Abstract:Extra-deep drilling is the only way to obtain deep physical data and establish a deep channel into the earth’s interior， which plays an increasing important role in the exploration of oil， natural gas and other energy resources. The selection and optimization of drill pipe material is one of the most critical core technologies that restrict the development of extra-deep drilling， which directly affects the drilling depth limit， drilling efficiency and economic cost of extra-deep drilling. This paper analyzes the problems faced by drill pipe materials from the complex loading conditions of extra-deep drilling drill pipes， combines the performance characteristics of steel drill pipes and lightweight drill pipes， compiles the domestic and international solutions for deep-well drill pipes， and summarizes the three key technologies of steel drill pipe toughening and regulation， corrosion-resistant treatment of drill pipes， and stress-concentration treatment， which provides a reference for the research on the development of extra-deep drilling drill pipes.

Abstract:Real-time recognition of formation lithology is critical for promptly adjusting drilling parameters， effectively controlling wellbore trajectory， and identifying subsurface reservoirs. Compared to traditional methods of identifying lithology， real-time recognition through monitoring parameters while drilling offers advantages such as convenience， efficiency， real-time accuracy， environmental compatibility， and energy efficiency. In this paper， around the lithology identification technology based on real-time parameters while drilling， the parameters according to different applications such as coal exploration and oil and gas reservoir exploitation are classified. Through the analysis of the current research status of drilling measurement and control technology and equipment， the technology for collecting and transmitting real-time parameters while drilling is introduced. Additionally， the characteristics and applications of machine learning algorithms， multivariate statistical analysis， grey relational analysis， and cross-plotting methods are also discussed. Through application cases， it compares and analyzes four types of lithology identification methods based on real-time parameters while drilling. Ultimately， the key technical issues in real-time lithology identification research is summarized， the deficiencies and challenges in development and engineering applications are analyzed， and the recommendations are provided.

Abstract:Natural gas hydrates is a new type of energy， characterized by huge reserves， cleanliness and high efficiency. China is rich in hydrate resources， and the safe and efficient exploitation of hydrates can help realize the transformation of energy structure and the strategic goal of “double carbon”. Hydrate reservoirs are generally characterized by non-rock formation， weak cementation and strong temperature and pressure sensitivity. The application of water jet technology to hydrate drilling process can effectively solve the engineering problems of well borehole collapse and formation destabilization caused by conventional methods. This paper summarizes the existing water jet drilling hydrate technology and water jet drilling tools， and analyzes the influencing factors and breaking mechanism of hydrate-containing sediment breaking process under the impact of water jet. Finally， the research direction for the application of water jet technology in the hydrate drilling process is prospected. This work can provide support for the research of natural gas hydrate development technology in China.

Abstract:With the decreasing of shallow energy resources of the earth and the gradual transformation to deep energy development， China’s hot dry rock geothermal resources have great potential， but the development and research is still in its infancy. Deep energy exploitation will inevitably face the problems of high temperature， high stress， high permeability pressure and hydrochemical environment. Therefore， the multi-field coupling effect of rock THMC （temperature field+seepage field+mechanical field+chemical field） is the focus of current research. In this paper， the method and development process of the multi-field coupling model are introduced， and the application in deep energy exploitation is summarized， especially the multi-field coupling problem in the Enhanced Geothermal System （EGS） and related experimental studies. The results show that the research on crack propagation， chemical stimulation measures and mechanical parameters in EGS is the key research problem. Moreover， the urgency and necessity of deep energy development are emphasized， which provides an important reference and guidance for future research and practice.

Abstract:The paper entirely elaborates the peculiarity， connotation and fundamental purpose of the new-quality productive force fostered in the practice. Important meaning that drilling technique could play a conclusive role with the new-quality productive force in the geological survey is analyzed and discussed aiming at the key meanings of the new-productive force and the challenges which humankind will have to face the energy-saving and lowing-carbon， green and environmental protection and climate change. Three key points of development direction for the drilling equipment and technologies that could form a proprietary intellectual property right and have a huge market prospective are pointed out. The paper predicts that the key development points will lead a innovation and revolution for the drilling equipment and drilling technologies.

Abstract:The construction of water conservancy projects is often located in remote or complex geomorphic areas. For the shallow geological survey of the above areas， there are higher requirements for the weight of the drilling rig， the migration ability in the complex terrain and the multifunctional of the drilling rig to adapt to the complex strata. Based on this， the application status of different types of （i.e. vertical-spindle， fully hydraulic with power head， sonic， and portable） core drilling rig in hydraulic and hydropower engineering survey is summarized， and their advantages and disadvantages are compared. In general， the engineering survey drilling rigs are developing in the direction of green， modular and multi-function. For the drilling rig selection in the survey of water conservancy and hydropower engineering should comprehensively consider the characteristics of different types of drilling rigs， so as to meet the specific task requirements such as hole depth， orientation， coring and in-situ test.

Abstract:Microbial-induced calcium carbonate precipitation can effectively fill and repair the inevitable hydration cracks during the cement slurry consolidation process， enhancing the mechanical strength and impermeability of cement stone， thereby reducing many induced well cementing quality issues. This paper focuses on Bacillus subtilis with good mineralization properties， investigating the mechanics and impermeability performance of cement stone under different process formulations and curing conditions， after activation and expansion cultivation of bacterial strains and their addition to cement slurries in various ways. The results indicate that environmental temperature， pH， and calcium source concentration are the main factors affecting the mineralization ability of the bacteria. The alkaline environment of the cement slurry （pH：11~13） has a significant inhibitory effect on bacterial activity， with a maximum reduction in mineralization ability of 15.1%. Porous and adsorbent shale ceramic sand carriers can effectively mitigate the influence of alkaline environment on bacterial activity. Compared to direct addition， the addition of carrier+bacteria can respectively increase the compressive strength， flexural strength， and impermeability pressure of cement stone by 11.5%，14.8%，and 33.3%. When the adsorption rate of the bacteria solution increases from 0% to 35%， the compressive strength， flexural strength， and impermeability pressure of microbial cement stone increase by 10.8%， 47.0%， and 25.0% respectively. Therefore， the microbial cement slurry studied can effectively improve the mechanical and impermeability properties of cement stone， providing valuable guidance and reference for enhancing well cementing quality and promoting the application of microbial cement slurries.

Abstract:Deep hot-water drills in polar regions are used to melt ice by means of high-temperature and high-pressure hot water and are mainly used for rapidly drilling through the ice cap and then lowering scientific monitoring instruments or obtaining samples of the under-ice environment into it. The return-water cavity is an important part of the deep hot-water drill. After drilling， the meltwater is returned to the return-water cavity， pumped by submersible pumps， and returned to the surface through the return water hose. Due to the very low temperature of the polar regions ice and the long return hose of the deep hot-water drill， this leads to the risk of the meltwater inside the return hose being frozen during the upward return process. Therefore， laying heat tracing cables with electric heating function in the return water hose is of great significance to avoid freezing of meltwater in the return hose and stable operation of the deep hot-water drill. At present， there is no research on the required heat tracing power of return water hose. For this reason， this paper firstly analyses the normal working condition， drilling stop condition， dry burning condition and thawing condition that the return water hose may face， and then establishes the numerical simulation method of heat tracing power in four working conditions based on the COMSOL Multiphysics 6.0 software， and mainly investigates the operating power， operating time and upper limit of the safe power of the heat tracing function of the return water hose. The results of the study give the operation strategy of the return water hose heat tracing function under the four working conditions， thus providing a certain reference for the design of the return water hose heat tracing cable.

Abstract:The physical and mechanical parameters of rock and soil are indispensable for engineering investigation， design， construction， and other operations， but conventional laboratory testing or in-situ tests have obvious accuracy errors. Accordingly， a real-drilling machine learning model was proposed in this paper which is used to predict the soil physical and mechanical parameters from drilling parameters. By collecting the actual data from several holes with the depth of 20 meters located in the National High-tech Industrial Development Zone of Zhuhai， the drilling pressure， torque， and triaxial vibration collected by the EP-200G drilling rig in real-time were used as input data， and the test data of soil cohesion， internal friction angle， water content and elastic modulus were used as output. Based on the established model， it is proved that the prediction accuracy of the machine learning models using single algorithms （including support vector machine， artificial neural networks and decision tree） can only reach 0.78 at most， while the integrated model based on the stacking concept can increase the prediction accuracy to a maximum of 0.98. Combined with this model， a sensitivity analysis between the drilling parameters and soil parameters was carried out， which confirmed that the drilling parameters would change significantly with the change of soil parameters， proving the reliability and applicability of using drilling parameters to predict soil parameters.

Abstract:In the strategic action of ore prospecting breakthrough， the drilling depth is constantly increasing， and intelligent working condition recognition has become a necessary measure for safe， efficient and low-cost drilling. Its steps include signal acquisition， feature extraction， state recognition and diagnosis decision， among which the establishment of accurate and reliable in-hole accident discrimination criterion is the difficulty and core of state recognition and diagnosis decision. Firstly， based on the theoretical knowledge and engineering practice experience of in-hole accidents， this paper divides the six types of accidents in drilling holes into buried drilling， stuck drilling， burned drilling， broken drilling， hole leakage and hole overflow， and summarizes their occurrence symptoms. The characteristics and change trend expression of real-time drilling signal parameters are analyzed in detail. On this basis， the relative mean， standard deviation， mean slope， standard deviation slope and their thresholds of six characteristic parameters， including pump pressure， drilling speed， torque， rotation speed， overhead weight and outlet flow， are proposed to characterize the change of each parameter. Finally， the accident discrimination criterion is established in the form of matrix. The discrimination criterion has strong theoretical and practical basis， and can divide the detailed drilling accident categories in actual use， which can provide a discrimination basis for subsequent software development.

Abstract:During core drilling， it is common to encounter fractured or fragile formation. When the core enters the drill bit， due to the disappearance of confining pressure and the release of geostress， the core will break into blocks along the fractures. When entering the core tube， it forms a blockage form whcih hinders the entry of the subsequent core into the tube. In severe cases， the core will wear and consume each other， resulting in insufficient core recovery rate and the missing of formation data. Core blockage has become an important factor affecting core quality and drilling efficiency in core drilling. The state of core fragmentation and blockage morphology are complex， and it is difficult to grasp the mechanism of core blockage under the dynamic interference of drilling tools during drilling， making the core unblocking a major challenge in core drilling. By establishing a theoretical model of core blockage morphology， this paper analyzes the typical blockage morphology and variation patterns formed in the core tube after core fragmentation， suggestions on coring parameter specifications for formations prone to blocking are posed， and based on the typical core blockage patterns listed， the anti blockage methods are put foward and discussed.

Abstract:The near-bit measurement while drilling （MWD） system effectively avoids the data latency issues faced by traditional MWD systems， and antenna parameter design and optimization are crucial for improving signal transmission distance and stability. This paper presents an optimization study on the antenna parameters of a near-bit MWD system， exploring the relationships between antenna coil diameter， number of turns， load， and magnetic core with signal transmission distance through experiments. The results show that with an emitting coil of 100 turns and a diameter of 0.8mm， and a receiving coil of 180 turns and a diameter of 1.0mm， combined with a secondary power amplifier circuit and the use of ferrite cores or ferrite sheets， the signal transmission distance and stability are optimal. The research findings provide theoretical basis and practical guidance for optimizing the antenna design of near-bit MWD systems.

Abstract:In unconventional reservoir exploitation， underbalanced gas drilling technology overcomes the shortcomings of conventional drilling such as low drilling speed， long well construction period and low efficiency， and one of the key constraints to the gas drilling technology is the high efficiency of rock cuttings transport at the bottom of the well when drilling in deep formations. Since the gas drilling rock cuttings transport research mostly adopts spherical instead of real non-spherical rock cuttings， ignoring the influence of non-spherical contour on rock chip transport， resulting in the inaccurate characteristics of bottomhole jetting rock cuttings transport. In this paper， the non-spherical rock cuttings are produced by cutting sandstone with a PDC drill bit， and a PDC drill bit and high-pressure CO₂ jetting test platform are set up to investigate the effects of the sphericity φ of the rock cuttings， the jetting pressure， the rotational speed of the drill bit， and the volume of the rock cuttings on the rock transport. The results show that： the axial velocity of the non-spherical rock cuttings fluctuates greatly when they rise， and their start-up speed is faster than that of the spherical rock cuttings， but the velocity decays faster； with the increase of the value of φ， the axial velocity of the rock cuttings decreases and then increases in the wellbore， and the axial velocity of the rock cuttings decreases and causes the poor transport efficiency when the value of φ is in the range of 0.6~0.65； the axial velocity of the rock cuttings increases significantly with the increase of the CO₂ injection pressure， and the increase of axial velocity of rock cuttings at the distance of 35 mm from the bottom of the well can reach 221%； the increase of drill rotational speed increases the axial velocity of rock cuttings significantly close to the bottom of the well， and the average velocity is stable at 11.88 m/s when the rotational speed of the drill bit is in the range of 70~80 r/min， which shows a better effect of rock carrying； the axial velocity decreases and then increases with the increase of rock cuttings’ volume. The above study systematically elucidates the rock-carrying characteristics of PDC bit jet drilling， and provides a theoretical basis for the application of CO₂ and other gas jet drilling technologies.

Abstract:The viscosity of fluids can directly reflect the characteristics of different fluids， and its measurement is of great significance in identifying the quality of fluids and determining their direction of use. For example， the change of drilling fluid viscosity will affect the realization of lubricating oil function， and the viscosity parameter as a basis for the selection of the drilling fluid is particularly critical for the measurement of the viscosity of the drilling fluid. However， in the traditional rotary viscometer， the friction moment of the liquid acting on the whole inner cylinder is calculated to be large because the additional moment generated in the lower plane of the inner cylinder also acts on the spring at the same time， and the velocity gradient and shear stress at each point on the bottom flat surface are different， which makes the problem more complicated. In this paper， based on the traditional rotating cylinder viscometer structure， the calculation principle is improved and supplemented， and by using finite element software to analyze the flow characteristics of the double cylindrical winding flow， the simulation results are consistent with the theoretical analysis， which verifies the reasonableness of the derived formula. Applied to the flow characteristics of drilling fluid in intact formation， it can provide a basis for further research on the shear stress of drilling fluid in fractured formation， and provide support for the prevention of in-hole accidents.

Abstract:There are many researches on cementing implementation methods and engineering detection methods of cementing quality， but the analysis of picture results on cementing quality is relatively rare. In this paper， a text coordinate position reference algorithm for focusing image analysis range and an image analysis algorithm based on histogram similarity and gradient distance are proposed to evaluate cement quality using evaluation image. A combination of image analysis algorithm and business mechanism is used to extract quantitative data from the evaluation image to evaluate cementing quality. Through comparison of model experiments， the proposed image analysis algorithm can accurately identify the cement quality information in the picture， and the error rate between the analytic results and the actual results is less than 10%. The method proposed in this paper can effectively solve the shortcomings of low efficiency and large error of manual analysis， and provides a practical solution to the situation that electronic data of cementing quality is missing and only the cementing quality evaluation image is kept. The proposed algorithm has strong exploratory significance for deep mining of cementing quality pictures.

Abstract:Ionic rare earth ore is a unique mineral resource in China and rare in the world. It dominates the global supply of medium and heavy rare earth， and has the characteristics of complete distribution， many high-tech application elements and great comprehensive utilization value. However， in the process of ionic rare earth mining， the well wall is prone to collapse， resulting in slope instability. This paper analyzed the calculation model of the critical velocity of the migration volume of the ore body particles under different influence factors. The results show that the critical flow rate of the ore particles increases with the particle radius， arrangement angle and friction coefficient. Electrostatic power is affected by the concentration of immersion liquid， but it has little influence on the migration of ore body particles. In addition， the viscosity of the solution can significantly reduce the critical flow rate. This study can provide theoretical and technical support for the safty and efficient development of ionic rare earth.

Abstract:With the large-scale implementation of deep geothermal resources exploration and development， deep drilling technology and geothermal reservoir protection and restoration are facing new challenges and problems. At present， almost all deep geothermal drilling projects are using circulation boring method of water-based drilling fluid，which caused the damage of geothermal reservoir. In terms of geothermal reservoir restoration there are no compulsory standard in China. As a result， after the completion of geothermal Wells， many of them enter into the depressurization or pumping test without standardized geothermal reservoir restoration， resulting in the wrong evaluation of geothermal resources and contract disputes. This paper is based on a large number of geothermal drilling engineering examples， combined with oil and gas reservoir reconstruction literature. The damage type， lithology， mineral composition of plugging and filling， restoration and stimulation mechanism of geothermal formation are studied.The test and engineering practice show that hydrochloric acid （HCl）， mud acid （HCl+HF） and supercritical carbon dioxide can dissolve， expel， displace and expand the blockage or fracture in geothermal reservoir， which is the basic method to restore geothermal reservoir and improve the reservoir ermeability.The single restoration method is not effective in practical application， and the “two-in-one” or “three-in-one” method should be adopted in combination with the mechanism and degree of formation damage. In view of the common problems at present， the basic methods of restoration and stimulation technology for different types of geothermal reservoirs are put forward， in addition， the restoration and reconstruction of geothermal reservoirs should be an important part （working procedure） for geothermal drilling engineering.

Abstract:The exposed karst region in Guizhou features a complex network of underground river systems characterized by extensive karst development and intricate hydrogeological conditions. These systems are highly susceptible to severe contamination from surface pollutant sources due to percolation of leachates. The pollution pathways within these underground river systems are challenging to precisely identify owing to their concealed nature， narrow spatial extent， and anisotropy. To expose and identify contaminated channels， drilling operations face several difficulties， including alternating soft and hard layers， non-uniform weak zones， significant karstic formations causing borehole deviation， large cavities leading to casing misalignment or breakage， and slow tracer migration due to low natural hydraulic gradients in the underground river systems. Consequently， the identification and exposure of pollution pathways are both difficult and inefficient. To address these challenges， several technical measures were employed， including anti-deviation and vertical maintenance techniques， large karst casing passage and sealing， and in-hole activation to promote tracer migration. These measures ensured the verticality of exploration boreholes， facilitating accurate logging， tracer testing， and water sampling. This approach enabled the precise exposure and rapid identification of pollution pathways. The methodologies and technical measures adopted in this study offer significant reference and practical insights for the precise exposure and efficient identification of pollution pathways in similar geological formations.

Abstract:Core is the most intuitive and practical data for understanding geological strata and ore bearing characteristics. The heart rate of conventional coring tools used in complex geological resource exploration often fails to meet the requirements of standards or design. When conducting mineral resource exploration in mudstone， mudstone shale interbedded and other mud prone formations， scaling occurs on the inner wall of the rope drill pipe， causing the inner pipe to not be fully inserted and unable to be used； The miniaturized single action double tube coring drilling tool is relatively short and only used for coring in mineral layers； The use of a single tube coring drilling tool is a "squeezing force" jamming method between the core， retaining spring （or rock powder， retaining material）， and drill bit （or core tube）， which often leads to uncertainty in the recovery rate of the secondary core due to the high degree of uncertainty in the fit between the three， and the core recovery rate cannot be guaranteed. To this end， a controllable local hot melt drill bit for drilling using dry and wet drilling methods was developed by utilizing the temperature at the bottom of the hole and the bonding temperature of the adhesive ≤2 times the melting point temperature of the adhesive ≤2 times the allowable temperature of the dimmonds materialthe. The core clamping method was optimized to use a “lifting” core to seal the inner diameter of the drill bit with a core claw， and core sampling experiments were conducted in combination with a single tube core tube. The core sampling rate reached over 75%， solving the technical problem of weak and uncertain core clamping in conventional single tube core tubes. This provides a new approach for drilling engineering construction in similar geological formations， which can be referenced， promoted， and popularized.

Abstract:When marine coring drilling encounters soft hard interaction formations， it is often necessary to lift the drill and replace it with a matching coring tool to cope with formations of different hardness. The cost of offshore operations is high， and frequent replacement of drilling tools takes a long time. Faced with the interaction of soft and hard geological conditions， an adaptive telescopic rope coring drilling technology has been designed. When encountering soft formations during drilling， the inner pipe extends ahead and the drill bit installed on the inner pipe performs coring drilling； When encountering hard formations， the inner tube will compress its internal spring under the reaction force of the formation on the drilling pressure， and then retract into the outer assembly of the drilling tool. The core drilling is carried out by the outer assembly drill bit， and under the adjustment of the compression spring， the core drilling method can be automatically adjusted according to the change in formation hardness. Through engineering application testing， the average core recovery rate of this process is high， achieving the goal of ensuring core quality and extending the working life of the inner pipe drill bit， improving operational efficiency and safety， and providing certain reference significance for marine engineering investigation.

Abstract:When drilling in fractured formations， conventional wireline coring tools are prone to core jamming， shortened round length， and reduced drilling efficiency， which is particularly obvious in deep holes. At present， the wireline coring hydraulic hammer technology has an excellent core anti-jamming function. However， due to its complex structure， high technical requirements， and high price， its popularity is not high. In practice， there is a lack of wireline coring tools with good core anti-jamming functions. The project has developed a new HQFD type wireline coring vibration anti-jamming coring tool. Among them， the anti-jamming inner tube assembly is the core of the research. The fixed-size development is carried out while keeping the length and diameter of the conventional HQ inner tube assembly unchanged， which is conducive to the efficient replacement between the inner tube assemblies. The pump volume requirement for the efficient vibration of this tool is highly consistent with the recommended pump volume in the HQ specifications and standards， and the additional pump pressure is low， which can achieve the core anti-jamming function at the minimum cost. The first generation of the HQFD type vibration anti-jamming coring tool has completed the research and development work such as the selection of the vibration principle， the layout of the functional mechanism， and the evaluation of the vibration effect. The new coring tool provides a new option for the core anti-jamming of wireline coring.

Abstract:In order to solve the problem of low efficiency of core drilling in ultra-long horizontal holes， a cordless core drilling process is proposed to complete the delivery and recovery of the inner tube assembly by mud hydraulic drive. To this end， this paper designs a positive/reverse circulation switching mechanism for the borehole mud that assists the delivery and recovery of the inner tube. This mechanism can realize the positive/reverse circulation switching by changing the mud flow direction through the mutual cooperation of two dual-channel ball valves. Through the ANSYS software， the L type double channel of the positive/reverse circulation switching mechanism is simulated， and the results show that after the fluid passes through the L type channel， the high-velocity fluid only accounts for 50% of the total amount of fluid， and the pressure drop of the fluid through the ball valve channel is 1008.1Pa， and the fluid near the inside of the channel will produce a lot of turbulence， resulting in different degrees of backflow. For this reason， the shape of the channel was optimized， the original L channel was changed to a circular channel， simulation results show that the fluid through the circular channel， high-speed fluid accounted for 90% of the total amount of fluid through the ball valve channel pressure drop is only 105.3Pa， and the fluid trace overall smooth， only a small amount of fluid reflux occurred. The optimized fluid channel is effective in reducing the pressure drop through the ball valve. The optimized fluid channel effectively reduces the head pressure loss and ensures the stable transportation of the fluid.

Abstract:During the coring process of coalbed methane， changes in pressure can directly cause changes in parameters such as gas content and porosity of the coalbed core， which can lead to deviations in the detection of coalbed gas content and theoretical research on coalbed methane reservoir formation. At present， the pressure holding coring tool used for coalbed methane resource exploration has a pressure holding capacity of less than 50MPa， which cannot meet the precise exploration needs of deep coalbed methane resources. In response to this problem， a deep coalbed methane pressure holding coring tool has been developed with a pressure holding capacity of 60MPa and a single core length of 6.5m. The strength and safety of the tool have been verified through theoretical analysis， numerical simulation， indoor testing and other methods. Three pressure holding coring operations were carried out in a coalbed methane exploration well in Inner Mongolia， with a cumulative footage of 9.4m and a total core length of 9.12m. The average core recovery rate was 97%， and the pressure holding success rate was 100%.The research results indicate that the developed deep coalbed methane pressure holding coring tool has reliable performance and can provide new tool and method support for precise detection of unconventional oil and gas resources such as coalbed methane and shale gas.

Abstract:The self-excited vibration rotary percussion drilling technology can improve the rock breaking efficiency and the ROP.The application test in a test well located in the northern part of the Jizhong region were presented.The drilling diameter of the test well section is 215.9mm， and the BHA is PDC bit+ZJXC-178 self-excited vibration impact tool. The field application tests are carried out in two well sections， the test drilling section and the subsequent well section. Through a meticulous analysis and comparison of torque， bit usage， ROP and cuttings in the same well and adjacent well， the self-excited vibration rotary percussion drilling technology significantly improved the drilling speed， achieved the speed increase effect of up to 73.4%， and the footage of a single bit also increased by 48.2%.The effectiveness of this technology in improving drilling efficiency is verified. While ensuring the rock breaking cutting force of the bit， the sudden change of torque is effectively reduced， and the stick slip vibration of the bit is significantly inhibited， so as to achieve speed increase and protect the bit at the same time.

Abstract:The “four in one” drilling tool is a directional drilling tool that combines the drill bit， screw， short drill collar， and stabilizer in a fixed order. It has a double stabilizer rigid structure. By utilizing the characteristics of a single bending screw， it is possible to achieve anti deviation straightening in the straight section， sliding directional drilling in the inclined section， and composite drilling in the stable， increased， and lowered sections. This article focuses on the different effects of different “four in one” drilling tool combinations on wellbore trajectory control. Combining with the construction case of Tao7-15-17X1 natural gas development directional well drilling project， the key factors affecting wellbore trajectory control by this drilling tool combination are discussed. The main reasons why different drilling tool combination parameters affect wellbore trajectory control are analyzed， which is of great significance for promoting the development of directional well trajectory control technology and improving the efficiency of directional well drilling construction.

Abstract:Casing directional drilling technology is a new type of directional drilling technology， which has the advantages of both casing drilling and directional drilling， and can achieve efficient directional drilling targets. As a key component in the casing directional drilling system， the performance of the locking device will have a direct impact on the drilling reliability. In this paper， a structural form is designed to seal all the parts of the moving mechanism of the lock， and the bearing capacity of the torque transfer and axial limit in the lock is calculated and analyzed. The two-parameter Mooney_Rivlin superelastic constitutive model is used to analyze the assembly clearance of the key seal O-rings at both ends and the sealing pressure of the rubber hardness. When the locking core is subjected to the maximum braking torque of 65011N·m， a single torsion key is subjected to the torque of 10835N·m with a stress of 74.86MPa， and a single positioning card can withstand the vertical bearing capacity of 184520N with a stress of 659MPa， both of which are less than the yield strength of the used material of 930MPa. The axial bearing capacity and torsional performance of the lock meet the design requirements. Mises stress and shear stress will increase when the gap is smaller. Excessive stress will damage the seal ring and make it difficult to assemble. The simulation results show that the contact pressure on the surface of the O-ring is greater than the external pressure within the selected tolerance range. Therefore， the fit gap is selected with large value； The greater the rubber hardness， the better the sealing performance of the O-ring and the smaller the deformation of the O-ring under the same medium pressure. By numerical simulation， the O-ring with 90HA hardness can meet the sealing requirements of the lock.

Abstract:The stuck drill accident is the most difficult accident to handle in mineral resource exploration core drilling. Traditional methods such as strong pulling， strong jacking， strong twisting， and reverse drilling of drill rods have extremely low success rates， and the program is cumbersome， time-consuming， labor-intensive， and cost-effective. To solve the problem of handling stuck drilling accidents， a vibration pipe extractor has been developed. When in use， the machine is installed on the drill pipe at the orifice， and when powered on， high-frequency and high-voltage vibration is generated. Then， the main winch of the drilling rig is used to pull up the vibration pipe puller+drill pipe combination， and through the combined effect of lifting+vibration， the blockage is relieved. The vibration pipe extractor is sturdy， durable， easy to operate， and cost-effective. It has been applied to deal with dozens of stuck drilling accidents on drilling sites， with a success rate of over 90%， and has significant promotion value.

Abstract:In order to improve the wall protection and anti collapse performance of solid-free flushing fluid during geological core drilling， five types of curing agents were selected， including alicyclic curing agent EPR， fatty curing agent DETA， AEP， aromatic curing agent PU， and amide curing agent PET. The use of curing agents can improve the film hardness， adhesion， weather resistance， and increased glossiness of the cured material. Adding curing agents to solid-free flushing fluid can improve the anti collapse performance. Through core immersion tests and linear expansion tests， it was determined that curing agents EPR and PU have a good effect on improving the anti collapse performance of the wall protection. Then， EPR and PU were compounded， and the optimal ratio of EPR∶PU=1∶4 was determined through core soaking test results. Finally， the optimal dosage of curing agent was determined to be 0.2% through linear expansion test and rheological performance test. The dosage of the solid-free flushing fluid is water+0.5% polyacrylamide + 0.04% EPR +0.16% PU， which improves the anti-clapse and wall protection performance with little impact on the rheological property of the flushing fluid.

Abstract:Reservoir damage mechanism has been widely studied， but the research of reservoir protection technology needs to be further in-depth. In view of the importance of reservoir protection， an acid soluble fiber is prepared by alkali oxidation method. By optimizing its particle size distribution and evaluating its acid solubility， it is confirmed that the combination of the fiber and rigid particles can achieve the purpose of reservoir protection. Drilling fluid additives （lubricants， fluid loss reducing agents and coating agents） for reservoir protection were optimized. The evaluation of lubricity， fluid loss reduction and rheology showed that the additives had good lubricity， fluid loss reduction and rheological properties. A drilling fluid system that can be used in reservoir was prepared. When acid soluble fiber and drilling fluid for reservoir are used at the same time， its rheological property can meet the construction requirements， with excellent salt resistance， good sedimentation stability and excellent reservoir protection performance. The field application in A coalbed methane well in Qinshui Block shows the excellent performance of acid soluble fiber and drilling fluid for reservoir， which is expected to be further applied.

Abstract:Using thermal insulation cement in the upper non reservoir section of geothermal extraction wells will be beneficial for increasing outlet temperature and improving energy utilization efficiency. Vitrified microbeads have been widely used in building exterior wall insulation due to their advantages of light weight， low cost and low thermal conductivity. However， due to its poor adhesion between the passivated surface and the cement matrix， the strength of the composite cement decreases linearly with the increase of its dosage. This article uses methods such as acid corrosion， high-temperature burning and spraying silane coupling agents to carry out surface modification of vitrified microspheres， and uses the modified vitrified microspheres to prepare geothermal insulation cementing cement. The surface morphology of vitrified microspheres before and after modification was characterized， the effects of modified and unmodified microspheres on the strength， hydration products， and interface morphology between microspheres and cement matrix were studied by micro testing methods such as SEM， XRD， etc. The following conclusion can be drawn： for microspheres with lower density， when mixed with cement of equal mass， the cement matrix does not cover the surface of the microspheres enough， resulting in a rapid decrease in the strength of the cement stone after its addition； After curing at 60 ℃， the compressive strength of the modified vitrified microsphere cement increased by 173.5%， and the addition of magnesium fluorosilicate further enhanced the strength； After modification， the increase in surface roughness of microbeads promotes the adhesion of hydration products， enhances the activity of microbeads involved in the overall hardening process of cement， and improves the bonding between cement matrix and microbead surface， collectively improving the strength of cement stone.

Abstract:According to the requirements of promoting green exploration and constructing a modern equipment system that integrates ecological protection and mineral exploration breakthroughs， this paper explores the application of modular drilling technology using unmanned aerial vehicles （UAVs） for typical forest covered terrain in southern regions. The performance and suitability analysis of TF-500 series heavy-lift unmanned helicopter systems and ZY-800P portable fully hydraulic modular drilling rigs are conducted， focusing on their application in the detailed exploration of gold deposits in the Yueguangchong Mine Area， Xinhua County， Hunan Province. This technology demonstrates outstanding environmental adaptability and practicality， utilizing UAVs’ flight capabilities for efficient， precise hoisting and transportation of drilling equipment， significantly shortening the relocation cycle， minimizing ecological impact， and enhancing operational safety and efficiency.

Abstract:The Equipment Organization of the Mineral Exploration Office of the Ministry of Natural Resources has conducted research on mineral exploration equipment and comparative analysis of mineral exploration technology and equipment at home and abroad. The results indicate that after decades of accumulation， although progress has been made in the development of exploration technology and equipment in China， there are still some shortcomings and challenges. Overall， the current geological exploration team in China is equipped with outdated equipments， limited green advanced equipments， and mainly imported advanced instruments and equipment. The domestic research and development support capacity is insufficient， the level of equipment industrialization is not high， and the safety guarantee conditions for field life are poor. It is urgent to strengthen the construction of mineral exploration equipments， support the comprehensive promotion of green exploration， and meet the new demand for mineral exploration equipment in the new round of breakthrough strategic actions. The China Geological Survey Bureau of the Ministry of Natural Resources has taken the lead in accelerating the construction of a modern field condition guarantee system， and has successively formulated institutional documents such as the Guiding Opinions on Strengthening the Use of Geological Survey Field Comprehensive Support Bases. The main task is to promote green exploration and shorten the gap with advanced equipment levels abroad. To meet the requirements of the new round of strategic mineral exploration and the refinement of national major engineering surveys， the HRD800F horizontal core drill was developed. The power head is a key component of a core drilling rig. This article elaborates on the design scheme， design process， and testing process of the power head for this type of core drill， and summarizes the performance characteristics of the power head.

Abstract:This article focuses on the problem of scaling on the inner wall of the drill pipe during the diamond wire-line coring drilling process， which affects the smooth salvage of the core. Based on the research results at home and abroad， the main factors affecting the scaling on the inner wall of the drill pipe are systematically sorted out， and a calculation program that can conveniently and quickly calculate the scaling index I and critical diameter D_c is developed. It has been applied on site in scientific drilling projects， providing useful scientific guidance for on-site drilling engineers to prevent scaling and ensure safe and efficient drilling.

Abstract:Roughneck is a safe and efficient tool for screwing and unscrewing drill pipes， gradually replacing hydraulic and pneumatic tongs and becoming a standard configuration for automated drilling equipment. As the core component of roughneck， the shackle pliers are crucial to the performance of the entire iron roughneck. By analyzing the structural principle and working method of the shackle pliers， we conducted an oil cylinder selection and mechanical analysis. This led to the design of a highly efficient shackle pliers structure for the RN254 roughneck， which was then tested in field production. The test shows that the scientific structure design of the shackle pliers and the reasonable selection of the oil cylinder greatly improve the work efficiency of the roughneck， providing a reference for the design and manufacturing of roughneck.

Abstract:RN254 Roughneck is an independently developed wellhead automated unscrewing equipment by the Exploration Technology Institute. It can safely， quickly， and smoothly connect and detach drilling tools within a range of 3.5 “to 10”. Based on the analysis of the integrated application and functional requirements of general drilling platform automation equipment， the RN254 roughneck electronic control system was designed with the design concept of modularization and integration of platform equipment， combined with the operating conditions， mechanical structure， and hydraulic system of the RN254 roughneck. The system uses S7-1200 PLC as the control core and Profinet as the communication method， integrating all components of the roughneck in an orderly manner， achieving one key automatic control of single step action or multiple action sequence combinations. Through actual field production tests and joint debugging in the factory， the RN254 roughneck has performed well in all actions， with stable and orderly control of the main engine， verifying the feasibility and reliability of the electrical control system， improving the automation level and safety of drilling operations， and providing reference for the development of intelligent drilling equipment in the future.

Abstract:In offshore oil production trees or subsea equipment pipeline systems， when it is necessary to perform switching operations such as opening and closing the pipelines， manual operation is not feasible in deep-sea environments. Therefore， work-class ROVs or underwater measurement and control systems are typically employed for remote control. This paper aims to achieve a multi-state working mode of the RMR lift pump group pipeline， establishing an underwater HPU system based on the principles， parameters， and structural design of underwater hydraulic systems. Selection of hydraulic control ball valves as the actuator， and a reliable testing scheme for ball valves adapted to the underwater working conditions of RMR is proposed. A design for a pipeline switching system suitable for the RMR lift pump group has been completed. This research has a wide range of application value for the RMR lift pump sets and other underwater equipment pipeline switching systems design.

Abstract:The pump is an important equipment for RMR of deep-sea drilling， usually placed in deep water. In order to conveniently monitor the operation and working parameters of the pump in the ship deck control room， this paper designs an RMR underwater pump monitoring system. The hardware of the system includes three parts： underwater measurement and control unit， umbilical cable， and deck monitoring unit， which are responsible for collecting pump working parameters and working screens， supplying power and transmitting information to the pump， displaying and controlling pump working parameters. The use of optical transceivers and umbilical cables can achieve long-distance signal transmission. The underwater measurement and control unit adopts two PLCs of the same specifications， which have the advantage of modular design. The upper computer of the system is programmed using LabVIEW software， which has the advantages of simple operation and user-friendly interface. The lower PLCs is programmed using Easybuilder software， which has the advantages of powerful library functions and good readability. The upper computer and lower computer communicate through the standard Modbus RTU protocol. The system underwent software and hardware integration testing， and the upper computer was able to read and display data from external devices of the lower computer normally， control the on/off， start/stop of external devices， indicating that the system can well meet the monitoring requirements of RMR underwater pump. And the system also has advantage such as scalability.

Abstract:Riserless mud recovery drilling （RMR） is an emerging green and environmentally friendly drilling technology aimed at solving the problems of material loss and environmental pollution caused by mud discharge in open water drilling without mud recovery channels. The innovative mud recovery liquid level identification and control system solves the problem of identifying the interface between mud and seawater in the turbid field of open water drilling. The system consists of the mud level identification system and mud level control system. Firstly， the collected images of mud and seawater are transmitted to the mud level identification system to obtain the measured mud level. Then， based on the deviation between the measured mud level and the preset mud level， the mud level control system is used to automatically adjust the pump volume to maintain the wellhead mud level at the designed level. By building the land testing platform for experimentation， it has been verified that the RMR liquid level identification and control system can accurately identify the mud level and automatically control the pump flow rate， and can automatically respond to well kick and leakage. The overall performance of the system is reliable， achieving the original innovation of deep-sea drilling technology equipment.

Abstract:In the investigation of water resources and hydroower engineering， the pump-in test is often carried out. In order to improve the efficiency of pump-in test， a portable pump-in tester with airbag isolation was developed， and the tester can be used with wire-line core drill tool. During the testing process， without lifting all drill string out of hole， the portable tester can be quickly lowered down to the hole bottom from the hollow of the wire-line core drill string， and the pump-in test was conducted by using rubber airbag and air-water diversion device. In this paper， the working principle， structure compositions and key techniques of the portable tester are introduced in detail， and the field test is conducted in a hydropower project in Yunnan Province. The field test results show that the tester structure is simple， high reliability， low manufacturing cost， and it can significantly reduce labor intensity， improve production efficiency during the test. Furthermore， it can be made out to ?75mm， ?91mm and other specifications according to the practical application， which solves the challenge of wier-line core drilling technology promoted in water resources and hydropower industry.

Abstract:A large number of salt lake drilling construction projects have been implemented in Qinghai Province， and the implementation of green exploration is required. This article takes the No. 9 potassium mine exploration hole in the Mahai area of Mangya City， Qinghai Province as an example. Based on the actual construction situation on site and the natural ecological situation of the mining area， the layout of the living and construction areas was reasonably planned. The main factors causing environmental disturbance were analyzed， including the temporary road construction， vehicle driving， project site construction， drilling engineering construction， etc. Corresponding green exploration measures were also formulated. This can enhance the awareness of green construction among geological drilling practitioners， forming green exploration habits， and provide replicable and referenceable green exploration experience for other units to carry out geological drilling constructions in landscape areas covered by aeolian sand.

Abstract:With the comprehensive implementation of the new round of strategic breakthroughs in mineral exploration， the workload of mineral resource exploration continues to increase， and the contradiction between drilling engineering construction and environmental protection is becoming increasingly prominent. Guided by the concept of green development， it is particularly important to strengthen the application of green exploration technology and methods to reduce environmental damage in current drilling construction. This article introduces a series of green exploration techniques in the Yanzhupo work area of Mufu Mountain， including the use of a portable fully hydraulic drill for construction， the use of small tracked transport vehicles for relocation， the use of iron circulation tanks， geotextiles， and anti-seepage membranes to reduce flushing fluid and oil leakage pollution during site layout， the use of environmentally friendly drilling fluid and flushing fluid centrifuges during drilling， and the treatment of waste liquid， waste materials， and garbage after drilling completion， as well as site restoration. These measures reduce the damage of construction to the environment and provide valuable experience for future green drilling construction， and it is suggested to improve the standards and specifications for green exploration， increase the budget for green construction， explore unmanned aerial vehicle assisted relocation and high adaptability drill bases， and promote the effective implementation of green exploration construction.

Abstract:Green exploration， as an advanced concept，has been increasingly valued and promoted by the majority of geological work. Based on the topographic and geomorphologic conditions of Tsavalong plateau area in Xizang and the requirements of deep well electrode， the paper discusses the exploration location， drilling construction and management of small diameter geological exploration borehole and the protection of natural ecology.

Abstract:The shallow overburden of salt lake has the characteristics of strong water solubility， poor cementation， developed fractures and pores， etc. Boreholes are prone to problems such as diameter shrinkage， collapse， corrosion peeling， leakage， etc.， which further leads to borehole accidents such as tool stuck， drill buried， pump suppression， etc. Therefore， it is necessary to improve drilling technology to promote the quality and efficiency of engineering construction. Combined with the actual situation in the mining area， the project explored the combined wire-line core drilling technology of “short drilling tool+side-sprayed PDC bit+saturated brine flushing fluid+PVC tube protection wall”， by carrying out experimental research， optimizing the drilling parameters， improving the saturated brine flushing solution ， preferably selecting the core bit， modifiying the wire-line coring winch according to local conditions， designing and developing the single-double action joint of layered pumping test device， these technical measures were successfully applied in shallow drilling construction and production of salt lake， which ensures the high-quality and efficient implementation of drilling engineering.

Abstract:The iron ore body in the Yangling Iron Mine area of Gansu Province is located in the fourth lithological segment of the Pingtoushan Formation of the Jixian system， which is composed of shallow metamorphic clastic rocks interbedded with muddy marble rock layers. The upper part of the strata is complete and has strong abrasiveness， while the lower part is severely fractured and leaked， exhibiting strong ferromagnetism. In response to the construction difficulties caused by the complex geological formations mentioned above， such as low drill bit lifespan， frequent accidents in the hole， and severe magnetic interference， measures such as optimizing drilling structure， selecting drilling equipment reasonably， and improving the use of flushing fluid have been taken to effectively solve the above problems. At the same time， it has played a positive role in accelerating construction progress， improving drilling efficiency， and saving construction costs. This drilling technology experience has certain reference significance for drilling construction in other strong magnetic mining areas.

Abstract:The Dongbeizhai Gold Mine is located in the Songpan seismic belt， dominated by strongly water-sensitive phyllite strata with extremely complex stratigraphic conditions. Collapse， diameter reduction， rockfall， and low core recovery are the main problems faced by core drilling in this area， greatly affecting the drilling efficiency and hole formation.This article aims to address the formation characteristics of the project and the characteristic of the construction equipment， which is all fully hydraulic drills. Through extensive and in-depth research， based on the lessons learned from previous construction experience in the mining area， by optimizing equipment performance， improving equipment adaptability， using multi-diameter drilling and a inhibitor flushing fluid system with good adaptability to the formation， combined with comprehensive drilling techniques such as follow-up drilling， pump-free dry fishing， and diamond wireline three-layer tube coring， the construction efficiency and quality have been improved， and good results have been achieved. This comprehensive drilling construction technology has good promotion and application value for the efficient use of full hydraulic drills in the construction of complex strata such as strongly water-sensitive phyllite in the northwest region of Sichuan.

Abstract:The coal resource exploration project in the Shenjing block， Zhongwei City， Ningxia， is an urgently needed local mineral resource project for energy supply. The drilling work needs to be conducted in winter when the lowest temperature is -21℃. During the construction period， great challenges exist due to the influence of low temperature and strata fragmentation. The main coal seams were dominated by fine coal， which leads to the highly difficulty of coring. By using a low-temperature resistant flushing fluid system， reasonable maintenance of drill diesel engines and other equipment， optimization of drilling tool combinations， and improving the anti-cold and warm kepping conditions for construction personnel， the winter drilling construction is successfully completed， with an average monthly efficiency of 811.8m/month.

Abstract:In the detailed investigation project of talc mine in northwestern Hunan， modular full hydraulic drilling rigs were used for drilling construction， penetrating multiple layers of shale and mudstone formations， and breaking rocks. This paper analyzes various technical problems encountered during the drilling construction process， such as drilling rig capacity， flushing fluid， and borehole annular gap， and proposes countermeasures， which have a certain reference value for the construction of similar mining areas.

Abstract:In order to survey the background properties such as the plane and vertical spatial distribution of the black soil surface matrix in the Qiqihar work area， 320 soil boreholes were designed with a drilling workload of 1600 m. It is required to take 0~5m undisturbed soil samples， which are sampled according to the principle of layering to determine the characteristics of the layering structure and physical and chemical properties of surface matrix. To ensure the quality of the project， the GL-10 backpack drill was used， which is a handheld hydraulic cylindrical soil sampling drill. It uses a hydraulic power head to drive the impact round chisel and drill rod for impact drilling， which effectively solves the limitations of traditional drilling and the problem of sample contamination. This article elaborates the drilling technology and working principle of the backpack drill， and demonstrates their outstanding performance in various aspects. During the survey of the construction process， the backpack drill showed its flexibility， portability， and efficiency， as well as its reliability in obtaining accurate surface matrix samples and data. The results indicate that backpack drill can adapt to complex and diverse surface conditions， providing a convenient and effective technical means for surface matrix survey， significantly improving the accuracy and efficiency of survey work， and having important practical significance and application value for promoting the development of surface matrix survey technology.

Abstract:The small-diameter directional drilling is an important technology to solve the problem of high-precision ore-controlled exploration and drilling. In view of the broad-spectrum adaptability of the PDC bit in small-diameter directional drilling construction for the hard rock with thin and soft interbed in the Lanling iron ore area， through the optimization design of the crown shape of the drill bit， the blade arrangement， the PDC cutting tooth inlay welding angle， the hydraulic structure of the drill bit and the drill bit carcass， the ?98 mm directional drilling PDC bit was developed. After the application verification of three directional drilling holes in heterogeneous strata above medium hardness， the PDC drill bits have achieved satisfactory results in impact damage resistance， wear resistance， service life， etc.， achieving the goal of efficient rock crushing and continuous and stable directional drilling， which provids an effective solution for the design and manufacture of small-diameter directional drilling PDC bits.

Abstract:During the drilling construction in the Mingyuefeng area of Hunan Province， accidents such as hole shrinkage and tool stuck are prone to occur in limestone and mudstone formations， and casing is often used for wall protection. Due to the deep penetration of the casing and the limited lifting capacity of the portable drill， it is difficult to recover the casing. The method adopted is to use a hydraulic cutter to cut the middle of the casing for recovery. In the actual cutting process， the success rate of casing cutting is not high， mainly manifested as the casing still cannot be lifted out of the drilling hole after cutting， and the hydraulic cutting blade after cutting is prone to breakage， excessive wear， etc. The main reasons are incorrect judgment of the stuck point position and irregular cutting operation. In this paper， precautions for the use of hydraulic cutting tools are formulated to address the reasons of cutting failure. Cutting the casing according to relevant precautions can significantly improve the success rate of cutting.

Abstract:Hole +304 is a deep coal seam borehole drilled in Huacaotan mining area.The buried depth of main coal seam generally exceeds 800m. The coal quality condition is mainly broken coal， poor cementation， high risk of fragmentation， loosening and collapse. During the use of conventional sodium clay polymer flushing fluid system， complex accidents occur continuously. The polymer flushing fluid system with easy degradation and strong inhibition against collapse was studied， main formula： water+4% sodium clay+0.05% soda ash+0.3% hydroxyethyl cellulose （HEC）+0.5% degradable polymer （JP）+1% fluid loss agent +1% anti-collapse agent+1% degradable plugging agent +0.5% lubricant + weighting agent （calcium carbonate）， apparent viscosity 15~20mPa·s， fluid loss <5mL， dynamic shear force 8~10Pa. After experiments， the expansion rate of coal seam is less than 0.1%， using oxidation type gel breaker OPJ 1.0%， The degradation rate reaches 93.5%， the drilling footage is 1077.50m， and there is no collapse， diameter reduction and other complicated situations.

Abstract:In this study， the 1000m core drilling of hole ZK407 in the southern and peripheral gold polymetallic resources investigation and evaluation project in Shandong Zhaoping Belt is taken as an example to analyze the technical difficulties of deep gold deposit drilling in Jiaodong area under the background of fault development. The borehole is located in Qingshan village， Nanshu Town， southern end of Zhaoping fault zone. The gold deposit is mainly altered rock type and quartz vein type located in the fracture zone. In the process of drilling， some accidents occurred， such as groundwater pressure imbalance， hole collapse and block clamping， serious leakage and drilling burning. In order to solve these technical problems， some measures have been taken， such as casing isolation， adjusting mud performance， composite material plugging， top leak drilling and cement plugging. These measures have effectively solved the technical problems， achieved the expected goals， and provided qualified geological drilling and physical core data for the research of deep mineral mineralization theory and resource exploration in this area. The results of this study have important reference value for drilling engineering under similar geological conditions.

Abstract:The shale gas parameter Well Eheye 3 is located in the Yidu-Hefeng complex anticline and Hefeng syncline of the Enshi Xiang’exi Fold Belt in Hubei Province. The main purpose of drilling is to explore the sedimentary shale gas of the Permian Dalong Formation platform basin facies， as well as the mixed shelf sedimentary shale gas of the Qixia Formation. The designed well depth is 2300m， and the completed drilling depth is 2326m. This article introduces the drilling and construction situation of Eheye 3 well， focusing on the treatment of non return leakage in the shallow Jialingjiang Formation on the surface， the selection of high hardness siliceous limestone drill bits for the Gufeng and Maokou formations， and the design of anti inclination straight bending shell screw drilling tool combinations. Research has been carried out to improve drilling efficiency. The first shale gas parameter well independently established by the China Geological Survey has been completed， and physical data of target layer rock cores have been obtained. New discoveries have been made in the exploration of Permian Dalong Formation shale gas and Qixia Formation oil and gas in western Hubei， expanding the exploration area and new layers of Permian shale gas in western Hubei. The investigation and evaluation of shale gas in western Hubei have been conducted. Provided important technical support for development.

Abstract:Shale gas formation have developed fractures and poor cementation， manifested as rock fragmentation， poor water sensitivity， and low wellbore strength. During the drilling process， it is easy to encounter complex situations such as collapse， falling blocks， and diameter reduction， which can lead to instability of the wellbore， drilling jamming， and buried drilling accidents inside the hole. Research on deep exploration drilling technology for the geological survey well engineering of the shale gas geological survey project in Liuzhou， Guangxi， and the application of PVA1788 film-forming system without solid flushing fluid and film-forming anti collapse system without solid flushing fluid， rope coring fluid dynamic hammer drilling technology， new technology for expanding corrugated pipe wellbore protection， and directional drilling correction technology for screw drilling tools. Good construction effects have been achieved in a number of field applications.

Abstract:When the drill string is pressed against the wellbore due to poor mud cake quality， it is prone to sticking under the pressure difference between the drilling fluid column pressure and the formation pressure， which poses a challenge to subsequent drilling construction. In this paper， the mechanism of releasing filter cake in low solid drilling fluid system based on bentonite is analyzed， and the dissolution of filter cake in different concentrations of sodium hydroxide solution is discussed through experiments. The results show that the combination of OH^- with Ca²⁺ and Mg²⁺ increases with time and the 6% sodium hydroxide solution has the better effect on filter cake under the same condition. The application in Well WBD-1 shows that compared with acid soaking and oil soaking， the treatment time of foam alkali is faster， which can avoid larger downhole complexity， reduce the interference to the subsequent drilling fluid and save the drilling cost. The results have a reference value for the similar sticking processing.

Abstract:Sidetracking on the old well is one of the main means of stable and increase production in the Bohai Oilfield. There is an uncertainty of the cost for cleaning the well before sidetracking in complex wells. The formulation of reasonable sidetracking decision-making trees can effectively control the cost. This article sorts out the current status of the sidetracking design technology in Bohai Oilfield. In view of the problems in drilling design for complex wells such as sleeves and sieve pipes recycle， “falling fish” salvage and so on， based on the principle of “safety， economy， and efficiency”the sidetracing decision-making trees are formulated， such as the long-time casing recycle， the sieve pipes recycle or not， and the fish salvage or not. Taking the sidetracking design for 3 complex wells in Bohai Oilfield as an example， the application of the decision tree realizes the scientific design of the sidetracking solution. Compared with the conventional design method， it costs less than 15 million RMB. The decision tree proposed in this article has a certain promotion value.

Abstract:Since the development of Gulong shale oil in the northern Songliao Basin， due to the geological characteristics of the formation and the limitation of drilling technology，the horizontal wells in the test area all adopted three-layer casing well structure， and the 2000~2500m horizontal section of long horizontal wells have a 100% “one-trip drilling” ratio in ?311.2mm boreholes. The “one-trip drilling” technology of the ?215.9mm boreholes has gradually transited from the initial “one-trip drilling” of the inclined section and the horizontal section respectively to that of the inclined section+horizontal section. With the improvement of drilling technology of shale oil wells’ ?215.9mm boreholes， in order to further shorten drilling and completion period and reduce drilling investment， the application and practice of three-spudding to two-spudding and “one-trip drilling” of ?215.9mm hole was optimized in Well GY15-Q8-H1. In this paper， the optimization design process， technical difficulties， risks and practical understanding of countermeasures of Well GY15-Q8-H1 well are described in detail， which provides a reference for the improvement of shale oil three-spudding to two-spudding drilling technology and the reduction of drilling construction complexity.

Abstract:In order to ensure well control safety， existing plugging materials have been added to the drilled areas of Changqing Oilfield for common leakage. However， there are technical difficulties such as water hole blockage of drilling tools， lack of signal from downhole instruments， and low success rate of one-time plugging. Therefore， wireless drilling instruments and downhole power tools have been optimized， and matching drilling plugging slurry has been developed to achieve rapid plugging of the leaking layer while meeting the requirements of permeability. This has formed the Changqing area drilling plugging technology， which has been applied in more than 100 wells on site， increasing the success rate of one-time plugging by 23.54%， significantly shortening the plugging time， improving plugging efficiency， and ensuring safe and rapid drilling and completion of wells.

Abstract:Zhangji coal mine multi-branch well is a drilling project of 1 straight 5 branch wells deployed to find out the geological （collapse column， thin coal belt and graben， etc.） and hydrogeological characteristics of No.3 abnormal area.The main target layers of T3 hole are 3_up and 3_down coal seams， which have low mechanical strength， developed fractures and cleats， poor homogeneity and high shear stress. The wellbore of coal seam section is extremely unstable， and it is easy to cause wellbore collapse， lost circulation， stuck or even buried wellbore during drilling. By analyzing the main technical difficulties of drilling fluid operation， the polymer drilling fluid system for strong plugging and anti-sloughing of multi-branch wells is developed. The main formula is： base slurry+0.5%KPAM+1%ammonium salt +1%potassium humate+1%filtrate loss agent+1% anti-sloughing agent+3%NS plugging agent， viscosity 35~50s， density 1.05~1.2g/cm³， water loss 4~6mL. One main hole and five branch holes were drilled， drilling quantity was 2506.23m， hole formation rate was 100%， core recovery rate was 92%， which ensured the requirements of construction.

Abstract:The operation cost can be reduced effectively in open sea duing the ultra-deep water drilling. However， due to the influence of ultra-deep water and ultra-shallow （“double ultra” for short） environment， it faced with difficulties and challenges such as the swaying of cable logging instruments caused by shallow water surge， the difficulty of “entering hole” of cable testing instruments and the hidden safety problems of down-hole operation. In this case， the 20in casing is used to seal off the shallow surge to form an effective sealing. Making full use of the underwater robot to ensure the success of the instrument to “get into the hole”； The speed of the instrument is strictly controlled， and the dual monitoring mode of “ROV underwater + platform control panel” is adopted to ensure the safety of operation. A pilot test was made in several “double ultra” exploration wells in Qiongdongnan Basin， South China Sea， and several wireline logging operations were successfully carried out， detailed logging data were obtained， and operating costs were greatly reduced. This operation practice accumulated valuable experience for subsequent ultra-deep open sea operations， and provided a powerful technical solution for offshore oil and gas exploration and development to increase the reserves and production， reduce costs and increase efficiency.

Abstract:The Pinghu oil and gas field has entered the mid to late stage of development， and the development of deep high-temperature and high-pressure and marginal oil and gas resources is an important means of subsequent energy alternation. The development of deep strata with large displacement and horizontal wells is the only way to ensure production and stability. In view of the losses caused by the failure of wellbore leakage and pressure testing， as well as the failure of downhole tail pipe cementing at high temperature and high pressure in the Pinghu block， it is necessary to optimize the cementing process for high temperature and high pressure wells and large displacement wells in order to ensure wellbore safety and reduce operating costs， in order to meet the requirements of subsequent energy development and production replacement. This article starts with the difficulty of cementing PH-X high-temperature and large displacement wells， systematically elucidating the difficulties and countermeasures of cementing high temperature and high pressure and large displacement horizontal wells in the block. The aim is to explore a cementing technology that meets the requirements of Pinghu block for high-temperature and high pressure and large displacement wells， and also provide some reference and reference for cementing similar large displacement wells.

Abstract:Well Weire-1 is a geothermal exploration well deployed by Department of Land and Resources of Henan Province in western Taikang Uplift， South North China. The designed depth of the well is 3000m with the completion depth of 3306.80m， which is the deepest geothermal well in South North China area. The fault was well developed， and the reference materials from adjacent wells were lacking. The geothermal geology research is not thorough and the formation is extremely complex， which are prone to collapse and block falling during drilling. In view of the difficulties in drilling works， optimization of drilling equipment， drilling parameter selection， drilling fluid systems was conducted. These measures have ensured the smooth implementation of drilling operations and provides reference and guidance for the construction of deep geothermal drilling in this area. In addition， Thermal reservoir thickness， lithology， porosity and permeability， water yield， hot water temperature and other parameters of the deep thermal reservoir in the area were obtained by analyzing the physical core data， logging data and pumping test data， and the development characteristics and development potential of deep heat storage in this area are revealed， which provides a guiding direction for future geothermal exploration and development.

Abstract:Geothermal resource is a kind of clean energy. It plays an important role in promoting energy structure transformation and achieving carbon peak and carbon neutrality. With accelerating development of geothermal resources， geothermal directional wells have been increasing year by year. Directional drilling technology has become more and more important in developing and utilizing geothermal resources. In order to improve geothermal directional drilling speed and efficiency， paper analyzed the technical issues of geothermal directional drilling technology and the wellbore structures of geothermal directional wells in Tianjin. Geothermal directional drilling technology optimization includes anti-deflection technology optimization of vertical well section， choice of KOP， optimization of BHA and parameters， improved drilling fluid system. Application of geothermal directional drilling technology optimization can ensure better well trajectory and improve directional efficiency in 6 wells in Tianjin.

Abstract:Due to issues such as low production efficiency， high costs， high safety risks， uncertain brine solubility， and significant environmental impact associated with single-well salt mining， the technology for drilling horizontal intersected wells has continuously developed and improved in recent years. The JSV005-JSV006 wells in the Wuyang salt mine are a set of horizontally intersected wells deployed in the Wuyang depression. This paper systematically summarizes the connection and communication of these wells from various aspects， including wellbore structure， drilling assembly， drilling parameters， drilling fluid performance， directional well trajectory control and geological steering technology， and measures to prevent downhole failures. The focus is on addressing the issue of insufficient horizontal displacement using near-point pullback technology， providing technical support for future salt mining operations.

Abstract:In order to improve the mining efficiency and output of a potash mine in Qinghai province， the mining scheme of through wells is put forward， after water injection from horizontal wells， brine is extracted from vertical wells， which greatly increases the production of potassium salts. The sticking accident occurred in the initial stage of construction， which was perfectly avoided by optimizing mud formula， reasonable selection of bit and design of anti-sticking drilling tool. After the completion of 40 horizontal and vertical wells， the annual output of potash in this area has increased by 35000 tons， which proves that the scheme of using horizontal directional drilling technology to improve the efficiency and output of potash mining is feasible！ The related research results can provide theoretical basis and practical guidance for the subsequent use of horizontal directional drilling technology for soluble mineral exploitation.

Abstract:During the mining process， coal mining enterprises dump a large amount of coal gangue on the ground. Through the construction of a super-large bore hole near the ground coal gangue bin to the underground roadway， the solid waste of coal gangue produced can be transported to the underground gob， which can not only solve the environmental pollution of coal gangue on the ground， but also effectively control the movement and deformation of the surface， so as to realize the green and sustainable development of coal mines. In the construction practice of large diameter feeding hole in Beixulou coal mine， Tengbei mining area， Shandong Province， small diameter pilot hole is pre-constructed， 5-stage re-expanding hole is opened in one stage， and 4-stage re-expanding hole is opened in the second stage， and a large diameter feeding hole is drilled in a coal mine with positive circulation of mud and air lift reverse circulation of cone bit. Its mature construction scheme has certain guiding significance for the large diameter drilling project.

Abstract:The Transient Electromagnetic Method （TEM）， as an efficient geophysical exploration technique， has been widely applied in geotechnical surveys. For the voids formed during the deep mining of phosphorus ores， their unique geoelectrical properties provide ideal conditions for the application of TEM. The TEM technology is used to precisely locate the position and shape of the voids and to assess their association with water-rich fractured zones. Integrated with geological data， an in-depth comprehensive analysis has been conducted on the distribution range， water accumulation， and other conditions of the voids and karst water-rich areas. This provides a scientific reference for the survey of concealed disaster factors in phosphorus ore voids， and offers new technical means and theoretical support for the geological feature assessment and hazard identification of phosphorus ore voids， thereby providing a scientific foundation for the safe operation of related engineering projects.

Abstract:Safety is a fundamental prerequisite for the development of enterprises and a basic requirement for labor. To ensure that personnel of different cultural levels， professions， and age groups understand safety， a safety production work system of “everyone is responsible， each level is responsible， and each person fulfills their own responsibilities” is established. On the basis of confirming that the 4M1E analysis method meets the requirements of safety production compliance， targeting the main production factors such as man， machinery， materials， methods， and environment， the 4M1E analysis method is used to propose key control points and implementation measures for achieving safety production from the perspectives of safety function management and on-site safety management. This demonstrates that safety management is essentially controlling production factors， promoting people’s understanding of safety management and improving personnel safety quality. The research results can provide reference and inspiration for safety management in the geological exploration industry under the new situation.