Abstract:This paper mainly explores the key physical and mechanical parameters, and fracture initiation pressure range and distribution characteristics of oil shale in the Wangqing, Nong’an and Huadian areas of Jilin Province. Comparison and analysis of compressive strength, tensile strength, elastic modulus and Poisson’s ratio of oil shale in Wangqing, Nong’an and Huadian lead to the finding that the ranges of compressive strength, tensile strength, elastic modulus and Poisson’s ratio of oil shale are similar in Wangqing, Nong’an and Huadian of Jilin Province. The results show that the range of compressive strength of Jilin oil shale is 9 to 30MPa, and the average value is 15.35MPa; the range of tensile strength is 0.3 to 3MPa, and the average value is 0.95MPa; the range of elastic modulus is 0.22 to 9.9GPa, and the average value is 3.1GPa; the range of Poisson’s ratio is 0.2 to 0.5, and the average value is 0.33. Calculation of the fracture initiation pressure of oil shale at different burial depth indicates that the fracture initiation pressures of Wangqing, Nong’an and Huadian oil shale decrease in turn at the same burial depth. With the increase of burial depth, the fracture initiation pressure almost increases linearly. At last, the fracture initiation pressure of Jilin oil shale under different burial depth is found as: when d=200m, the range of the fracture initiation pressure is 0.5 to 2.3MPa; when d=400m, the range of the fracture initiation pressure is 1.0 to 4.5MPa; when d=600m, the range of the fracture initiation pressure is 1.6 to 6.8MPa; and when d=800m, the range of the fracture initiation pressure is 2.1 to 9.0MPa. Therefore, it is recommended that the pressure range should be controlled at 0.5 to 9MPa for the fracture initiation pressure of Jilin oil shale.

Abstract:A large amount of oil-based drilling cuttings is produced during deep oil exploration and unconventional oil and gas development, such as shale gas and tight gas. Thermal desorption technology is considered as the most effective technology for environmental protection treatment of waste oil-based drilling cuttings, and also an effective way to realize the resource utilization of oil-based drilling cuttings. This paper mainly introduces the typically advanced technology, equipment and application of thermal desorption of oil-based drill cuttings. In view of the complex and variable nature and composition of oil-based drilling cuttings, the complex pyrolysis chemical reaction process, the high energy consumption of thermal desorption equipment, the uncertain pyrolysis temperature, unstable and inhomogeneous feeding material, it is suggested to carry out investigation of continuous desorption dynamics and mechanism of the complex oil-based drilling cuttings system in the moving bed, establish the dynamic model, and define the optimal thermal desorption parameters for different components of oil-based drilling cuttings; meanwhile, establish the evaluation system and criteria of technical and economic benefits, environmental benefits and sustainable development, providing scientific and reliable basis and theoretical support for high efficiency, low consumption, safety and environmental protection thermal desorption of oil-based drilling cuttings in different systems.

Abstract:The geothermal Well CGSD-01 is located in Dongli Lake, TianJin and is part of the tectonic area of Tianjin Panzhuang Bulge. The design depth of the well is 4000m and the completion depth is 4051.68m. One of the main purposes of the well is to obtain geological data of various strata by staged core drilling. An effective coring solution has been found through attempts at combination of different coring tools and drilling methods, which successfully solved the problem of low core recovery in the third stage drilling in Wumishan Formation with high-quality cores obtained. Through comparative analysis of coring with various technical schemes, the key coring technologies for deep geothermal wells have been summarized, providing some experience and guidance for future core drilling.

Abstract:In recent years, the coal mine MWD system has been widely applied in CBM drainage, geological exploration and prevention and control of water disasters due to its advantages of high efficiency and accuracy. Through the field application of the mud pulse MWD system in Detong Coal Industry of Linfen city, Shanxi Province, the accuracy and efficiency of the wireline survey tool and the mud pulse survey system is compared. The result demonstrates that the mud pulse system can be widely used in high position directional holes.

Abstract:Well Heifudi-1 is a small diameter geological survey well for oil and gas, and in the context of drilling of the well, the basic principle and operation steps of the gas logging is introduced in this paper. The problems encountered and relevant solutions in gas logging are described. The evaluation principle for abnormality detected by gas logging in the well is explained and used for evaluation of gas formation encountered in the well. With reference to the results and experiences of gas logging, this paper analyzes the influence of major factors on gas logging data accuracy and logging curve continuity, explores the operating procedure of gas logging in small diameter geological survey wells for oil and gas, and describes the effect of small diameter drilling characteristics on the evaluation of oil and gas reserves.

Abstract:This paper mainly introduces drilling of Hole ZKS001 in the silver polymetallic mine in the Sijiagou-Kuanping section, Xiaoshan District, Shan County, Henan. It is a straight hole with the design depth of 900m. The upper strata are hard, broken, with well developed fractures, serious leakage, and falling blocks. There were many difficulties in drilling in this zone such as low penetration rate, difficult coring, serious wear of drill bits, which resulted in drill pipe fractures many times during drilling. The drill hole is located at the intersection of the valley and gully with serious water gushing. Many mud interbedds are present between the borehole depth of 200m and 460m, which resulted in borehole diameter shrinkage. During drilling, due to improper handling of many drilling technical measures, drilling was difficult, and accidents often happened, delaying the construction period and increasing the construction cost, which should be taken as a lesson for future operations.

Abstract:With analysis of the existing drilling information of Hole ZK1403 in Henan Banchang Mining Area, a deviation correction plan was determined according to the geological requirements of directional deviation correction. An effective directional deviation correction process with the slim hole mud motor was developed in terms of deviation correction drilling theory with the slim hole mud motor, drilling equipment, instruments, drilling procedure and drilling parameters. Successful deviation correction was achieved from the hole depth 958m, inclination 10° and azimuth 143° to the hole depth 1100m, inclination 7° and azimuth 18°. Based on the correction results in the mining area, both the advantages and disadvantages of the process were summarized, providing reference for deviation correction in deep geological hole drilling.

Abstract:Tahe Oilfield is an important oil and gas production area in China, and lost circulation endangers production safety in the field. Lost circulation in Tahe Oilfield happens mostly in the Permian, Carboniferous and Ordovician strata. The causes can be summarized as below: well developed fractures in the Permian strata, highly sensitive Carboniferous strata and large crack-holes in the Ordovician strata. In this paper, the geological characteristics of Tahe Oilfield are summarized with the resulting down hole incidents such as lost circulation expounded and analyzed. At length, the technical methods for lost circulation prevention and plugging in Tahe Oilfield are summarized, providing some reference for the future exploitation in this region.

Abstract:Portable full hydraulic drilling rigs are widely used in green exploration drilling. There is no matching mud purification equipment due to the influence of the mud drilling process and the footing area of portable drilling rigs, leading to some problems, such as waste of water resources, lack of environmental treatment of waste mud. Through comprehensive analysis of various mud purification methods, the miniature high frequency double-layer circular screen shaker was put forward to purify mud, which provided good peformance, and was economic and practical, meeting the requirements of green exploration.

Abstract:According to the project requirements, wellhead water injection tests need to be conducted in the drilling process to detect its leakage and other failures based on the water absorption of boreholes and the pressure data. In the conventional way of wellhead water injection tests, drilling tools should be lifted out of the borehole, which severely affects the construction schedule. The development of the split type wellhead device allows the test to be done without lifting the drill string up, which is of great economic value and practical significance as it saves time, reduces labor intensity and safety accidents. This paper introduces the structure, working principle and application of the split type wellhead device developed for water injection tests without tripping the drilling string, and compares it with the conventional wellhead water injection devices through tests to verify its reliability and advantages.

Abstract:This paper relies on the deformation accident of the steel piles in the pile foundation of the Dawangshan mine pit project. Through theoretical analysis combined with the actual situation, The deformation treatment and mechanical analysis of the steel casing of the pier pile foundation in the karst area are carried out. The main research conclusions are as follows: (1) The deformation treatment of the pile steel casing adopts the gas cutting steel casing and the correction deformation method in the jack hole. It is supported by internal support, C30 high-flow concrete filling and grouting reinforcement; (2) The steel inner support adopts 80mm*80mm*2.5mm rectangular steel pipe, and the circumferential arrangement is divided into three triangles, and the vertical spacing is 0.5m. (3) The eight grouting small pipes and four small pipes are embedded in the piles and inserted into the caves to grout. The grouting reinforcement effect is obvious;(4) The gas cutting method is cut layer by layer. The cutting height of each layer is 50cm, the ring direction is divided into three pieces for cutting, and the two semicircles are bent by 2cm thick steel plate, and the welding is closed into a ring. The research content of this project can provide theoretical and engineering practical support for similar projects.

Abstract:The project team of China Geological Survey “Land Trial Production of Natural Gas Hydrate in Sea Area” has constructed a drilling test site in the coastal beach area of Dongying City, Shandong Province. The foundation soil of the site is typical silty clay in the Yellow River Delta, which has the characteristics of micro-vibration liquefaction. By comparing the advantages of cost, construction period, environmental protection and applicability, the project team chose the construction scheme of lime-soil cushion and strictly controlled the construction quality. Lime-soil cushion can form effective water-proof layer, isolate groundwater rising channels and surface water seepage channels, avoid the causes of micro-vibration liquefaction, and eliminate the seepage of construction waste water in the site. At the same time, static compaction was used throughout the backfilling construction to avoid the upward migration of pore water and micro-vibration liquefaction effect of soil. The backfilling area is divided into heavy-load area and light-load area. Different backfilling schemes were adopted, which not only met the bearing capacity requirements, but also saved costs. The backfilling schemes have achieved good construction results, ensuring the smooth operation of the test site.

Abstract:By analyzing the stress state of soil around a pile and friction characteristic of the pile-soil interface during the load bearing process of the pile foundation, a calculation model of shear strength of soil based on stress state of soil and calculation model of shear strength of interface based on friction characteristic of pile-soil interface is derived. By comparing the shear strength of soil with that of the interface, the calculating model of ultimate shaft resistance under the influence of the coupling of the two kinds of strength is derived, and the rationality and feasibility of the model is verified by an engineering example in Shanghai, and the distribution law of ultimate shaft resistance of different types of soil with buried depth is analyzed by using the model. The results show that, due to the different relations between the internal friction angle and the lateral pressure coefficient, the ultimate shaft resistance shows different distribution characteristics with buried depth, and in a certain relationship, there is a critical depth beyond which the ultimate shaft resistance is maintained at a stable value or even reduced constantly to zero.

Abstract:In petroleum and geological exploration drilling, PDC bits have obtained good drilling results in middle hard and some hard rocks, resulting in satisfactory technical and economic indexes, and been accepted by drilling users. However, while they are used in complicated formations, such as drilling in hardness-changing formation, fractured formation and abrasive formation, the penetration rate is often slow with short bit life. In order to tackle above-mentioned problems, Russian specialists have designed a new elongated, stabilized and vibration-reduced PDC drill bit. Laboratory and field experimental results with the bit show that the bit is effective in the field with good technical and economic results.

Abstract:In order to tackle the problems of fast wear and short life of impregnated diamond bit in abrasive formation, the WC was added to iron base prealloyed powders as matrix metal owing to the characteristics of high hardness, high wettability and good abrasion resistance of WC. The hardness, impact toughness and bending strength of the matrix sample with different WC contents were tested to find the influence law of the support metal WC on the matrix performance. The results show that with the gradual increase of WC contents, the hardness, the impact toughness and the bending strength of the matrix sample exhibit the same trend: increase first and then decrease. From the perspective of micro-structure and energy, the reason of this rule is analyzed. Finally，it is concluded that the matrix achieves the optimal performance when the sintering temperature is 830℃ and the WC content is 5%. In this case, the strength and abrasiveness of the matrix sample are the maximum.

Abstract:Green exploration is the concrete embodiment of green development in geological work. China began green exploration relatively late. Up to now, there has not been a unified evaluation method and standard yet at the national level, which restricts the understanding of green exploration. With review of the national and local guiding principles and standards for geological exploration, the advances are summarized since the implementation of green exploration in China, and analysis is made of the policies and evaluation standards for geological exploration implemented in different ecological zones by major mining countries abroad. Finally, in view of geological exploration problems and current situation, regional distribution of mineral resources and economic situation in China, green exploration evaluation methods and criteria are proposed for different ecological zones. The impact of geological exploration is quantified, and it is recommended that exploration work should reach 95 points, 90 points and 85 points respectively in ecological conservancy areas, fragile areas and general areas to meet the green exploration criteria. It is proposed that China should change the geological exploration policies for ecological conservancy areas and fragile areas, so as to keep ecological environmental protection in pace with resource exploration and economic development.