Abstract:In the full length core drilling in well Qiansuidi-1 of southern China, the winch sensor installation was realized by processing the simulation winch, the suspended load sensor was replaced by the installation of a switch and the pump punching sensor was installed on the pulley protection cover, which made the gas logging being smoothly carried out. The main factors affecting the gas logging results in well Qiansuidi-1 are the reservoir, drilling fluid, drilling engineering and degasser. In order to reduce the misunderstanding of gas logging data, it is necessary to strengthen the training of logging personnel on site to effectively eliminate the influence led by controllable factors on gas logging and improve the the accuracy of geological drilling gas logging to a certain extent to provide powerful data support for the division of shale gas formations in south China.

Abstract:Sticking accident happened at the drilling depth of 907.91m in Jiangxipo geothermal well, back-off was used after releasing failed, the remainded 75.53m drilling tool could not be taken out and the top end of the drilling tool was at the depth of 832.38m. It is necessary to adopt sidetracking to bypass the top end of the drilling tool for continue drilling. In the case of casing cementing completion, sidetracking window from inside casing was carried out with DXQ210/H type deflecting device selected as the deflecting tool and KCXZ216 type taper miller as milling tool. Based on the analysis on the general situation of the accident, the paper introduces the working principle of the deflecting device and the technical scheme of sidetracking window from inside the case and summarizes the attentions in the construction operation. The sidetracking is smoothly completed at the depth of 2364.56m.

Abstract:Houwujiahu gas field of Lishu fault depression is in the early stage of exploration and development, because of the deeply buried target layer, the design depth of follow-up production well has deepening trend. Based on the analysis on geological conditions in this area and considering the technical difficulties of drilling, this paper makes the application analysis and evaluation of drilling speed increasing in wellbore structure design and the use of drill bit and dynamic drilling tools, and puts forward measures and suggestions for the drilling speed increasing suitable for this area.

Abstract:At present, the azimuth drift often occurs in the drilling process of deep shale gas horizontal wells, which seriously affects the trajectory control of the horizontal well, and then affects the accurate target of the horizontal well. In the field construction in this area, usually according to the previous drilling experience, an “advanced azimuth angle” should be estimated before the directional slanting is carried out, but there are a lot of uncertainties in this field practice and there may be some big error. In this paper, a method of horizontal well trajectory optimization design based on azimuth drift is proposed, which solves the inaccuracy of “advanced azimuth angle” only estimated by the field experience. The optimization design of horizontal well trajectory is devided according to the well sections; the average azimuth drift rate of the well section is obtained by combining the stratigraphic factors with the well profile. Based on this method, the software for the optimization design of horizontal well trajectory based on azimuth drift is developed. The feasibility of this method is proved by the examples.

Abstract:In order to verify the difference between the round-hole screen pipe and the slotted screen pipe in the gas drainage process, this paper analyzes the passing performance of the conventional round-hole screen pipes and the slotted screen pipes with PFC3D discrete element analysis software. According to the simulation results, the slotting parameters are optimized, the gas drainage tests of the round-hole screen pipe and 3 kinds of the slotted screen pipe with different slotting parameters were carried out in coal seam 15# of 15117 working face in Yangquan mining area. The results of numerical simulation show that the volume of passed particles through the slotted screen pipes is less than that through the round-hole screen pipes; and for slotted screens, the effect of the slotted width on the volume of passed particles is greater than the slotted length. The field test shows that the average gas flow and gas concentration of the slotted screen pipe are 6 times and 3.8 times that of the round-hole screen pipe respectively, it proves that the smaller the volume of passed particles is, the better the anti-clogging performance is, and the better the gas drainage effect is.

Abstract:With the background of well ZK001 drilling project for potassium salt survey Xuanhan County of Sichuan Province, the drilling construction technology of potassium salt parameter well is summarized in well structure, drilling tools combination, drilling fluid technology, coring technology, well deviation control and deep pumping tests. In view of the technical difficulties such as super-long open hole drilling, hole leakage and long-section gypsum salt layer drilling in the construction process, by the countermeasures of optimizing drilling tools combination, adjusting the performance of drilling fluid

Abstract:The peripheral blocks in Sichuan Basin contain a large area of marine shale gas with low abundance and normal pressure, according to the current development costs, the reserves are difficult to be used, and it is urgent to carry out the low-cost technical breakthrough of drilling engineering to revitalize the shale gas resources. The research on low-cost drilling technology has been carried out in drilling, logging and cementing in Wulong area of southeast Chongqing. Based on the analysis on the causes of high drilling cost, the technical research and field practice are carried out mainly in the optimization of well bore structure, well trajectory control and drilling tools, leakage protection & control as well as the optimization of logging and cementing, etc. The test well Longye 2HF is composed of guide hole and sidetrack horizontal well, the drilling cost decreased by 30% compared with the adjacent well, which lays a foundation for the development of normal pressure shale gas in Wulong area.

Abstract:Because of the underground mining, a large number of goaf are formed, the collapse accident is prone to happen, especially for the mines from underground mining changing into open-pit mining, there are hidden dangers to the safety production of the mining area. In view of this situation, this paper studies a filling well completion technology for multi-layer goaf to carry out support treatment. By means of this process, the amplitude of rock movement can be reduced to prevent the large area of ground pressure activities, so as to provide guarantee for the production and safety. Due to the different conditions of the specific location, morphological characteristics and size of the goaf in each mine, the treatment methods for goafs are not the same. According to the characteristics of Luanchuan molybdenum mine goaf, this paper introduces the study and test on filling well completion technology.

Abstract:Aiming at the conundrum of goaf gas excess after working face mining, 3 long-distance coal seam roof large diameter directional borehole were constructed in 1029 working face of Taoyuan mine by using the directional drilling technology combined screw motor with MWD, the maximum hole depth is 531m and the cumulative footage 1701m(contains branch holes). Through the precise control of drilling trajectory, the borehole is extended along the crack zone of the coal seam roof, the gas in the goaf is effectively extracted after the coal seam mining. This paper summarizes a set of drilling construction methods of high position and long borehole in roof for gas control in the goaf to ensure the safe and efficient production of coal mines.

Abstract:In order to evaluate the economy of openhole cementing sidetracking in the same layer and openhole sidetracking in casing to optimize the way of sidetracking, the conventional design and operation processes of 2 wells by the same layer sidetracking are introduced. The period of screen pipe fishing in well abandonment and the economy of openhole cementing sidetracking are analyzed, by establishing a decision graph of sidetracking scheme, the key factors affecting the economy of sidetracking are seeked out, and the calculation method concluded for the economic construction period of screen pipe fishing and critical surplus construction period of the economy can be used as the decision basis for whether the screen pipe fishing scheme should be adjusted or not.

Abstract:Drilling is the most direct means to obtain deep geological information, which can identify the sequence of Quaternary strata, determine the depth and fluctuation of the top surface of the bedrock, verify the speculating model, study the geological structure, delineate the important contact relation between geological bodies and serve the geological mapping of overburden area. Geophysical logging is a scientific and effective means of well detection. Based on the characteristics of specific lithology or lithological association corresponding to specific logging parameter combination, the formation lithology can be identified, the depth and thickness of the stratum can be determined and the stratigraphy subdivision and correlation can be preceded by using logging parameters. The comprehensive utilization of drilling-geophysical logging technology will improve the exploration efficiency in overburden area and reduce exploration cost and provide technical support for the geological mapping of overburden area in the next step.

Abstract:In view of the drilling rod broken accident that often occurs in geological drilling, in this article, the main factors that lead to the wire-line drilling rod breaking are analyzed in the aspects of drilling rod material and processing, complex formation conditions and drill hole bending, and the corresponding prevention measures are summed up in drilling rod material selection, drilling rod processing and heat treatment process, thread structure optimization and fine processing, borehole structure and drilling tool grading optimization, wall protection and leakage plugging technology and field operation regulations. It is suggested that the drilling tools grading and drilling regulation parameters should be optimized by numerical simulation to strengthen the detection of drilling rod corrosion defects and crack, so as to improve the reliability of the whole drilling system.

Abstract:DB2-E5 is the first sidetracking horizontal well for grouting in Dongpang. This paper analyzes the drilling difficulties, presents the well structure desigh and branch well design trajectory and introduces the real drilling technical measures and DHA as well as drilling parameters in detail. The successful completion of this well is of great significance for Ordovician grouting, waterproofing, water control and drilling cost reduction.

Abstract:Hydrogeological and water well drilling are important parts of exploration engineering. With the increasing demand of underground water resources and requirement intensification of ecology and environment protection, the hydrogeological and water well drilling engineering become more important. In the well completion process, corrosion and scaling of the filter are often encountered, which directly affect the wellbore influent amount and pumping effect, and even lead to the filter being scrapped and water well abandoned. Prof. Третьяк А.Я., who works in National University of Technology in Southern Russia, and some others have invented a new automatic scale-handling water filter and resolved the filter corrosion and scaling in the drilling process.

Abstract:The ultimate aim of the oil shale in-situ pyrolysis technology is to heat the oil shale to the state of pyrolysis. Direct heating, which can be realized by heating in the well to achieve the highest energy utilization rate with the smallest heat loss, has become the main heating way of the in-situ pyrolysis. In this paper, a new type of downhole heater with spiral baffle is developed, and due to the spiral continuos distribution, the contact time of gas and heating rod can be effectively prolonged to remarkably increase the heat transfer coefficient of heat rod surface. This paper also focuses on surface heat transfer characteristics of the in-situ pyrolysis heater with spiral baffle. Through the numerical simulation and theorecical deduction, the effects of the spiral baffle’s pitch and the gas mass flow on the heat transfer coefficient of the heating rod surface is analyzed, it is concluded that the smaller the pitch of the baffle or the larger the gas mass flow the higher the heat transfer coefficient of the heating rod; in the meanwhile, the fitting equations for heat transfer coefficient of heating rod surface changing with the pitch and gas mass flow are obtained to provide the theoretical support for the following-up design of the heater with spiral baffle.

Abstract:Based on the research and optimization analysis on the drilling mechanism and cutting structure of the rotary drilling bucket, according to the problems in the rotary drilling process, such as low drilling efficiency; poor guidance of centering tip and being easy to slip; ineffective residual soil collection; outer edge teeth holder wearing and the tips of outer edge teeth being easy to break; much sediment at the hole bottom and wall and the structure type of the soil leading plates can not meet the engineering requirements, the structural design of centering tip and soil leading plates are optimized and improved, as well as the cutting teeth distribution, teeth quantity and the rock cracking angle. By the optimized improvement, the drilling efficiency is improved by 80%. In addition, the labor intensity is alleviated, the bit service life is extended and the construction cost is reduced, the practice provides the theoretical basis and experience for the structure design and application of the rotary drilling bucket in the future.

Abstract:Take the example of Dasuji molybdenum mine in Inner Mongolia, the analysis is made on the forms of damage and types of geological hazards in the geological environment of open pit mine on the basis of the present mining situation, the further harm to the mine geological environment by the production activities are predicted and the restoration and treatment plan of the mine geological environment is put forward. This paper mainly describes the whole process of flood control dam completion from its design to the concrete construction, as well as the technical measures such as the restoration and control of the open pit and treatment of dump and tailing pond.

Abstract:The main lithology of the strata that Liangshui tunnel crossed is carbonaceous phyllite with poor geological conditions, the surrounding rocks are broken with high breaking degree and joint development. Since the construction of Liangshui tunnel in 2009, the problems of tunnel engineering have come out in an endless stream. The preliminary support cracking and failures happened, even serious tunnel structure failure such as cracking of the secondary lining, block falling and inveted arch uplift occurred, which led to slow construction progress. In the section of imported pile number of DK359+712～ DK359+742, good results have been received by double-layer preliminary support and single-layer secondary lining. The analysis on the stress situation provides a basis for the support mode selection of carbonaceous phyllite tunnel.

Abstract:The sedimentation column tests and particle analysis experiments are performed on the waste slurry of a bored pile in Wenzhou to study the influence of organic flocculant APAM and inorganic flocculant CaO on the mud settling property and particle size. The influence of different addition order of inorganic flocculant CaO on the flocculation effect of organic flocculant APAM are focused on. The results show that: on the basis of less APAM addition (10mL), CaO adding can increase the mud initial sedimentation amount; adding CaO then adding APAM is not conductive to APAM flocculation; in case of adding CaO later, the effect of CaO on the final flocs particle size mainly depends on the strength of the floc itself and the stirring intensity.

Abstract:In the mining system of potassium salt mine of Ganmeng Province in Laos, the ventilating shaft passes through carnallite and halilith, which are easily soluble in water. After the ventilating shaft excavating, cavern phenomenon, a serious threat to the normal function of the shaft, is found behind shaft wall. In order to ensure the safety of shaft construction and the normal production, curtain grouting is adopted to control the disease of ventilating shaft. The closed curtain grouting technology is adopted with the method of grouting from the top to bottom and with effect checking while grouting to finish the reinforcement and water plugging. The cementing materials used for carnallite and halite layer were tested in laboratory, a new type of grouting material, brine + magnesium oxide slurry was determined together with the scientific grouting mix ratio. By the summarization, the design and construction experiences are accumulated for waterproofing and water blocking in potash mine mining process.

Abstract:In order to ensure the correct application of the post-grouting technology for the holing cast-in-place pile with slurry retaining, this paper analyzes the mechanism of post-grouting technology to the cast-in-place pile with slurry retaining hole and the application status, some corresponding measures or suggestions are put forward based on the analysis on the factors that affect the application effect, such as the qualification of the employees, the quality of the completed holes and piles, grouting valve, grouting pump and the relevant grouting parameters.

Abstract:Tube well dewatering is widely used in the construction of underground works for its high drainage efficiency with simple equipment. This paper studied the scheme optimization of the tube well dewatering of a foundation pit by river and analyzed the key and difficult points in the dewatering process in high altitude area based on the constructin practice of dewatering project by river in Lhasa and with the reference of the actual construction effects and the actual construction conditions. As the dewatering scheme is more scientific, the dewatering efficiency is also improved.