Abstract:The development of earth sciences is more and more depending on the deep earth exploration data, the scientific ultra-deep drilling, known as “the telescope into the crust”, becomes an indispensable method for the research on deep geology. Compared with the steel drill pipe, the aluminum alloy drill pipe, with its unique superiorities (lighter weight, high specific strength, deep drilling depth and less energy consumption), has become the essential scheme for drill string design used in difficult to enter area, extended reach wells and scientific ultra-deep well and so on. From the perspective of popular science, this article describes the differences between drill string and drill pipe, the limit use length of drill string, the technical advantages of aluminum alloy drill pipe and the existing deficiencies, so as to improve our understanding of aluminum alloy drill pipe and promote the research and development of the aluminum alloy drill pipe.

Abstract:Directional drilling under coal mine is an important technology to realize efficient gas extraction and prevent flood water inrush. The method of rotary drilling is mostly adopts. In hard rocks, low drilling efficiency, long drilling cycle and high construction cost seriously affect the project progress and quality of gas extraction drilling. The drilling test results of the limestone strata of Zhaogu mine1 show that with reasonable control of pump pressure, rotary speed and weight on bit, the efficiency of impact rotary drilling by SC86H high energy liquid-jet hydraulic hammer is increased by 3 times than that of conventional PDC rotary drilling, and the drilling cost is saved.

Abstract:MWD comb directional drilling technology is mainly used in coal mine gas prevention and control, geological anomaly body detection and exploration & release of water and some other fields at present. However, this technology has not been combined with enhanced extraction technology by hydraulic fracturing permeability to apply in the field of coal seam gas prevention and control. Due to the special drilling requirement of enhanced extraction technology by hydraulic fracturing permeability, the breakthroughs should be made in drilling equipment, drilling design and hole completion. The results of this study combine the advantages of gas drainage technology by comb directional drilling and enhanced extraction technology by hydraulic fracturing permeability, a set of equipments and technological processes are formed, which is suitable to segmented hydraulic fracturing comb directional drilling construction, can meet the needs of long distance and regional permeability enhancing for the soft coal seam and solve the problems such as weak permeability of soft coal seam, poor gas extraction hole completion, short extraction distance and small extraction area.

Abstract:A new technology of in-situ pyrolysis of oil shale by high voltage-power frequency heating is proposed by Jilin University and Tomsk Polytechnic University, Russia. It has the advantages of small footprint, less pollution and simple technology. The two-step method is to use high voltage electricity to break down oil shale, then by electric heating to realize rapid pyrolysis of oil shale. In order to determine the technical parameters of oil shale pyrolysis and master oil shale pyrolysis technology by high voltage-power frequency heating, the thermal analysis on the pyrolysis process of oil shale under the conditions of with or without oxygen are carried out. The test results show that the pyrolysis of oil shale can be completed under the aerobic and anaerobie heating conditions, and the pyrolysis processes are the same, all of which belong to two-step pyrolysis process. Oxygen plays a driving role in the pyrolysis of oil shale, which can reduce the pyrolysis temperature of oil shale, save energy and speed up the pyrolysis of oil shale.

Abstract:The cores with micro cracks were manufactured with metal foil and cementitious materials of different thickness, together with external cylinder of high temperature and high pressure water loss instrument and mud cup, the evaluation on micro crack plugging can be carried out. The verification is made by micro observation method and flow calculation method, the result shows that the micro cracks surface has a certain roughness and fracture opening is in accordance with the experimental design; the minimum crack opening is 3.33μm and the length of crack is 5～10cm. The manufacturing method of micro crack core is simple with high opening similarity. It is verified that the laboratory-made crack can be used to evaluate the plugging performance of drilling fluid plugging material, which provides core module for the evaluation experiment of micro crack sealing, and makes up the shortcomings of smooth crack surface by crack plate simulation and crack opening conversion when using porous media of sand bed, steel balls and sand plate.

Abstract:The research on “Air DTH Hammer drilling technology” was carried out by the Bureau of Geology and Mineral Exploration and Development of Guizhou Province, which was a part of the scientific research project of “Application research on deep well drilling technology in Guizhou complex strata”. During the test process, some typical accidents happened, such as the hammerhead fracture, hard alloy tooth fracture, impactor blockage and blocking, mud ring wrapping, drill pipe sticking & burying and borehole bending. The causes of these typical accidents are analyzed in detail, and the systematic technical measures to avoid and solve these typical accidents have been formed. The results are proved good through field inspection and this paper gives a comprehensive elaboration on this achievement in order to provide reference for the similar construction.

Abstract:Caojiakou gold deposit is located in Shandan County of Gansu Province. In the drilling construction in 2015, 2 full hydraulic power head drilling rigs were used, 4 drilling holes have been scrapped because of formation fracture, collapse and serious leakage. In order to improve the construction efficiency and quality, SYZX96 type wire-line coring hydraulic DTH hammer was adopted, and the evaluation analysis was carried out on the types of matching flushing fluid to ensure the best effect of the hydraulic DTH hammer. The field application results show that the footage per round trip increased by 68%, the core recovery rate was up to more than 95.5% in total and the average monthly efficiency increased by 21% with no downhole accident, which reduces the drilling cost and improves the construction quality and construction efficiency.

Abstract:The coal-bearing strata are mostly gray and yellowish conglomerate, sandstone, mudstone, mudstone and glutenite interbedded, mudstone intercalated coal seam or coal line in the eastern exploration area of Naomaohu coalfield in Xinjiang, among which, strata of mudstone, mudstone and glutenite interbedded have strong water sensitivity, poor cementation and are easy to cause hydrated swell, shrinkage and wall collapse in the drilling process, wall protection is difficult. In view of the characteristics of the mine strata, the inhibitory solid free and low solid drilling fluid are used, the borehole stability is kept and effective and safe drilling is realized.

Abstract:The detailed survey of Xianrenyan gold deposit in Changning City of Hunan Province is a focus scientific research project for Hunan Province Nonferrous Metal Geological Survey Bureau. Because of the high rock hardness, frequent changes of soft and hard formations, groundwater, karst caves, old complex galleries and some other reasons in this mining area, the construction is difficult with low drilling efficiency and core recovery rate is difficult to reach the standard. In order to solve this problem, through repeated tests and research, the improvement of flushing fluid and plugging technologies have been made and the mud system and plugging measures suitable for the construction in this area are developed. Some achievements have been received in complex formation drilling in Xianrenyan mining area.

Abstract:In order to improve horizontal well cementing quality in Honghe oilfield and meet the requirements of later staged fracturing, the horizontal well cementing technology in Honghe oilfield is studied. In view of the difficulties in horizontal section cementing, GSJ cement slurry system is selected through laboratory and field tests. Based on the measured formation pressure and formation rupture pressure, the balanced pressure cementing design is used to determine the annulus structure of slurry. In order to improve the displacement efficiency, the stabilizer type and placement location are optimized. The professional software simulation indicates that the centralized degree is more than 73%. High-quality well bore preparation and casing floating measure ensure smooth casing strings running down; the use of lengthened rubber plug, resin wheel rigid cyclone centralizer, shut-in valve and other accessories ensure the cementing quality. In the actual application in 53 horizontal wells, cement slurry all returned to the ground. CBL logging show that superior rate of cementing reaches 81.13%. This cementing technology is successfully applied in the horizontal wells in Honghe oilfield, which guarantees the cementing quality and meets the needs of later staged fracturing.

Abstract:Coalbed methane resource is very abundant in Guizhou Province. In the early stage of exploration and development, there are many drilling difficulties, karst cave were often encountered in the first section drilling with leakage, circulation lost, large dip angle and poor drillability; in the second section drilling, low ROP and thin coal seams led to low core recovery rate, these difficulties seriously restricted the exploration and development process of coalbed methane in Guizhou karst area. By the analysis on the formation characteristics and drilling difficulties of Guizhou karst area and based on years’ engineering practice, this paper summarizes a set of key technologies suitable for coalbed methane drilling in Guizhou karst area, including air drilling technology in the first drilling section, fast drilling technology in the second drilling section and wire-line coring technology. The research results can be suitable not only for the coalbed methane exploration and development in Guizhou karst area, but also can be reference for the coalbed methane exploration and development in other areas.

Abstract:During the construction of solid core drilling in coalbed methane exploration well, when encountering the tectonic development of rock strata and developed underground water system, multi-layer leakage and difficult wall protection often happen. Because of the special requirements for logging operation in coalbed methane exploration wells, the wall protection and plugging become the key of drilling construction. In the process of wall protecting and plugging treatment, some improper technical methods and incorrect calculation can lead to the failure, even cause major drilling accident. By the summary of the construction experience of the work area, the feasible technical measures of wall protection and plugging are put forward, which provide reference for the similar stratum drilling exploration and construction.

Abstract:This paper summarizes the construction experience of a geothermal well in Hasuhai scenic spot of Inner Mongolia. The well completion depth is 2232.59m, Petroleum 30 type drilling rig was used by full face drilling with rotary positive three-cone bit and matching with PDC bit coring drilling process. This geothermal well has 3spud structure, 80 mesh wrapped 80 mesh wire wrapping filter pipe. Both the water temperature and the water output meet the design requirements after well completion. The judgment and prevention measures of PDC bit balling are introduced.

Abstract:Most of the HDD projects in Shanghai area are conducted in sandy soft soil formations, and different special requirements of mud property should be taken into consideration. However, because of the similar property of the commonly used compound synergistic commercial bentonite, it is difficult to adjust the most favorable property in accordance with every single engineering case. Therefore, the main design points of drilling mud property in such engineering environments are discussed, the mechanism of material addition is analyzed and some useful and practical material technologies for parameters of mud density, viscosity and shear as well as water loss volume are given in order to provide a reference method for mud application under similar engineering conditions.

Abstract:The paper presents a project with typical dualistic-structural stratum in Wuhan, the average buried depth of the continuous sand layer is about 50m with no proper bearing layer for reasonable pile length, which makes cast-in-place pile sediment control difficult with low pile completion efficiency. More than 30mdepth fine sand with silty clay soil layer is selected as pile end bearing layer, the pile completion technology is verified through 2 separate groups of 14 testing piles with different pile diameters and pile lengths, comparing the load-bearing characteristics of these 2 groups, the shortage of value drawing according to standard empirical parameters is put forward, the post-grouting friction cast-in-place pile, 800mm in diameter and 30m in length, is selected as engineering pile parameter based on the comprehensive cost performance and bearing stability, which can provide the basis for pile foundation design optimization and can be the reference for the similar projects.

Abstract:Combining with the drilling practice of the detailed investigation for geotechnical engineering of China Railway world expo city and the matching projects, in view of the complicated formations, serious mud leakage, drill pipe sticking and burying in the drilling process, some effective measures, such as wall protection with high quality mud, grouting, casing putting and drilling parameters optimization, are taken to improve the construction efficiency and reduce cost, and obvious technical results have been achieved.

Abstract:Multi beam tensioning technique is mostly adopted for the tensioning of anchor cables of lattice beams. In a protection construction of the unstable slope cable lattice beam in Longnan of Gansu, it was difficult to carry out multi-beam tension due to the insufficient working length of the strand. A treatment scheme of combined application of single-beam tension technology and multi-beam tension technology is put forward. The construction technology and treatment effect are introduced in detail.

Abstract:Tao River water diversion is one of the most important projects of poverty alleviation and development in central Gansu during “The Tenth Five-Year Plan” period, with Jiudianxia water control project of Taohe River as the source of water, the water shortage in arid region in central Gansu is focused on. The administrative division of this project involves 6 counties of Zhuoni, Lintao, Weiyuan, Dingxi, Longxi and Yuzhong and the project includes 3 major landform units across mountain area of West Qinling, Longxi loess plateau and mountain area of Maxian mountain-Xinglong mountain. The geological condition is quite complicated with main geological hazards of collapse, landslide, debris flow and loess collapsibility. In this paper, the evaluation is carried out on debris flow, one of the main geological hazards, through lots of filed observation and in-situ investigation, and combined with the characteristics of linear engineering and debris flow distribution in this water supply project, the evaluation range is extended at both sides of the channel, the corresponding measures of hazard prevention and control are put forward.

Abstract:The important measure to eliminate or reduce the safety risk of tailing pond is to reduce the saturation line in the dam body, and the seepage drainage technology is the main means. Based on the application of some geotechnical engineering technology in the seepage drainage project of tailing pond and with a number of engineering practice, this paper discusses and summarizes the blind ditch drainage, horizontal hole drainage, radiation well drainage, well point pipe drainage and some other combined drainage measures about their principles, characteristics, construction methods and quality control points in tailing pond seepage drainage engineering technology.

Abstract:The shield receiving well in Nanjing Yangtze tunnel is located at the river island; the excavation is mainly in fine sand layer and gravel sand layer. In the dewatering construction, a series of difficulties are successfully overcome, such as thick strong permeability formation, great influence of confined water, deep excavation depth, close distance from civil house to foundation pit, complex dewatering technology and difficult ground settlement control. In this paper, the study and summary are made on the design of foundation pit dewatering, construction process and ground settlement control.