Abstract:With the rapid growth of market demand for natural gas, how to successfully develop the rich CBM reservoir in Ningwu basin becomes an important subject in unconventional gas reservoir development. It is one of the key factors to scientifically determine a suitable drilling fluid density window by combining with the crustal stress state, the parameters of formation pore pressure and formation strength, as well as angle of deviation and azimuth angle in order to realize effective and safe coal-bed methane industrialization development in Ningwu basin. The finite element model of No. 9 coal seam in Ningwu basin is established by ANSYS software, the influence rule of hole enlargement ratio is analyzed in the conditions of different crustal stress directions and different well inclination, by which the optimized range of mud density is obtained to control coal seam collapse and reduce complex prescription, and the support for research on improvement of drilling efficiency and comprehensive benefit of CBM in NingWu basin is found.

Abstract:Because of the increasing energy need in China, a lot of deep and complex reservoirs are to be exploited with more and more complex problems in drilling. The narrow safety density window of drilling fluid is one of the most prominent problems. MPD technology is the best way to solve this problem currently, which can be divided into constant bottom hole pressure system and micro-flux control system. By the analysis on these two basic styles of processes and equipments, the difference between these two systems is compared in order to provide recommendations for the further promotion of MPD technology.

Abstract:In Tengchong volcano-geothermal-tectonic zone scientific drilling project of Yunnan, while drilling in multi period volcano eruption formation, the complex conditions of hollow, slag, sand and leakage were serious. The paper introduces the large diameter air drilling tools, equipments and technical measures used in this complex volcano formation, which can be taken as reference to the geological engineering drilling construction in similar formations.

Abstract:The trial mining of gas hydrate is the only way which must be passed from the theoretical research to commercial exploitation. The steam mining is a combine mining method. Based on the pressure relief mining, hot steam is injected to the hole for thermal excitation in the gas hydrate target layer, which can avoid “self-preservation effect”, promote further decomposition of the hydrate and expand mining area theoretically. Numerical calculation was done on the dynamic process of steam heating hydrate layer by FLUENT software. Through the comparative analysis on the simulation results, it was decided that the best steam power was 20kW and the heat injection time was 38 hours in order to meet the requirements of the premise mining. In the natural gas hydrate production project in Muli basin of Qinghai, the steam mining lasted for 5.2 hours with the gas production of 3.25m3.

Abstract:Flooding is one of the three major dangers that threaten the safety production in coal mine. Exploring and discharging borehole construction is an important means to prevent and deal with flooding. The article elaborates the construction process of exploring and discharging borehole with directional drilling technology. The practice proves that by means of the directional exploring and discharging borehole, water information of target area may be accurately detected, which meets the requirements of water exploring and discharging in mine and provides technical support for safety production.

Abstract:In recent years, there has been a major breakthrough in shale gas exploration in Sichuan basin and its vicinity by SINOPEC, but the commercialization process of exploration and development is influenced by low penetration rate, long drilling cycle, high drilling cost and bad well completion quality in this area. In this article, the main challenges in shale gas horizontal drilling are summarized, air drilling limited by shallow formation water, low ROP due to large diameter of directed section, frequent circulation lost, hole deviation by air drilling and poor cementing quality in horizontal section with oil based drilling fluid. Aiming at the above challenges, the technical countermeasures are proposed in 6 aspects: shallow formation water control, test of directional drilling with foam drilling fluid, prevention and treatment for circulation lost, development of anti-deviation device for air drilling, cementing of shale gas horizontal well and research and application of multi-well pad drilling technology. All these can provide reference for the research on shale gas drilling technology and construction.

Abstract:Based on the test application of large fracture plugging agent in complex formation of Shennongjia mining area, the paper discusses the performance parameters and the plugging mechanism, summarizes the operation methods and briefly introduces the application process and the effects of this plugging agent in the field test.

Abstract:According to the characteristics of gravel, inclining, collapsing, leaking and strong abrasiveness in part of fault depression interval in Zhangwu work area, by establishing drillablility and three pressure profiles, the compound drilling tool of high efficient bit, single bend PDM PDC bit and new material & the measures are tested and promoted, which lays the foundation for the fast drilling to form a fast drilling technology series in Zhangwu work area.

Abstract:Well Yincan 4 is the first parameter well for Sinopec in Yinchuan District, the purpose of drilling is to investigate the stratigraphic sequence of Yinchuan basin and the development of Qingshuiying formation hydrocarbon source rock. According to the complicated conditions in drilling process, such as cementing, loose and collapsing in upper formation, bit bouncing in gravel layer of Ganhegou formation, mud pollution by intrusive fluid in Qingshuiying formation, drilling into a large section of unexpected salt gypsum layer and lost circulation of drilling fluid in mudstone fracture of Qingshuiying formation, which were considered in the design of wellbore structure and optimization of hydraulic parameters, straight screw drilling tool and inclining prevention BHA were used with large discharge and light pressure in the large section construction to effectively prevent bit bounce, high drilling speed and good well quality were achieved. The drilling fluid system suitable for the salt gypsum layer in this area is explored and the best ROP record of 39.09m/h is created with φ444.5mm bit.

Abstract:To solve the common problem of casing pipe breaking in DTH hammer drilling with casing and to increase the depth of drilling with casing, double shock of DTH hammer drilling with casing was adopted and casing pipe jar was designed to put external force to the top of the casing in the drilling process. By calculating the force of the jar and analyzing the factors on the maximum drilling depth of drilling with casing, this paper verifies that the impact generated by the jar can drive the casing follow-down smoothly, so as to solve the problem of casing pipe breaking and low depth of casing with drilling.

Abstract:φ219.1/168.3mm large diameter reverse circulation drilling tool is independently developed by Coalfield Geology Bureau of Henan Province, which has been successfully applied to large diameter engineering well with good results. In this paper, the preliminary analysis is made on various factors affecting air-lift reverse circulation drilling efficiency based on the basic production test data, it is concluded that the drilling rate has certain relevance to sinking ratio and air volume, but with little relationship to air pressure.

Abstract:It is a new trend to control landslide by using anti-sliding composite structure of micro-piles combined with other engineering measures, which has been largely applied in engineering practice for its convenient, low cost and high landslide stability being obviously increased by pressure grouting. Taking a landslide case of Xining-Jiuzhi highway as an example and based on the analysis on 2 existing slip zones of shallow layer and deep layer, a comprehensive landslide treatment measure is put forward: micro combined anti-sliding pile is applied with anchor frame beam consolidation and inclined drain holes. By the stability computation and rainfall test in rainy season, the feasibility and effectiveness of the comprehensive treatment measure by micro combined anti-sliding pile are proved.

Abstract:Fluid samples from deep boreholes can provide a variety of information, which is an important part of deep drilling engineering. This paper introduces a technology for borehole fluid sampling—U-tube sampling technology. By the research and analysis on the principles of U-tube technique, U-tube sampler was designed and developed with field tests; the sampling depth reaches 500m and the maximum flow is up to 40L/h.

Abstract:To ensure the scientific and effective drilling operation, a hook position monitoring system is designed based on LabVIEW. It can measure the hook position, provide real time display of hole depth, remanent distance of drilling rig, penetration rate and drill length. Meanwhile, a double channel hall sensors is installed on the crown block to detect the pulse signals, through the transformation of micro programming conversion by the digital display meter, serial port communication connecting PC and Labview platform, the data acquisition, analysis, presentation and storage are realized. The practice proves that this system has the advantages of convenient installation, high test precision and strong practicability and can be widely applied to the vertical drilling machine, rotary drilling rig and hydraulic drilling rig.

Abstract:Micro-drill experimental device 2000 (MDES 2000) can stimulate field conditions, including rock abrasiveness and drillability tests, the diamond bits performance parameters and service life tests and optimization of drilling practice parameter tests and can do some other micro-drilling experimental researches in laboratory. Drilling stimulation work can be made, and the monitoring, collecting and storing the parameters (bit pressure, penetration rate, rotary torque and spindle stroke) can be realized in drilling process with a database of drilling parameters report file being built. This experimental device has a great practical significance for the core drilling research.

Abstract:Taking a case of water inrush in Sangshuping coal mine, the paper discussed the grouting and water blocking technology used for the special large water inrush caused by being mined beyond the approved limits with unknown water channel. The engineering practice indicates that the situation of cross-border mining must be firstly detected to determine the general location of water interception; then the water inrush channel should be detected by geophysical methods and based on the geophysical information, the water channel position is pinpointed with downhole drilling. After dynamic water interception, the grouting is carried out in the coal seam floor and the top of Ordovician limestone.

Abstract:Bad geological conditions are often encountered in bored pile construction process, which cause local collapse of hole wall and soil mixing into concrete in the concrete grouting; these lead to bored pile broken, concrete defects in pile body and insufficient bearing capacity of pile end. High pressure circulation grouting with steel pipe underpinning reinforcement technology can be very good to deal with the problem. Take high pressure circulation grouting with steel pipe underpinning reinforcement technology as the research object and with the engineering case of pile foundation reinforcement, analysis is made on the design, calculation and application; the reinforcement effect is tested by core-collection, test results show that the bearing capacity of pile foundation meets the design requirements after reinforcement.

Abstract:Proceed from actual engineering, the paper summarizes the work of drilling, sampling, geological logging and hydrogeology observation, and elaborates the importance of the field work for geotechnical engineering investigation.

Abstract:It has been more than 5 years since “Technical code for building pile foundation”（JGJ 94-2008）was implemented on October 1, 2008. As an engineering technician, the author elaborates the conformity and suitability in the revision and implementation of this technical code for years from construction angle, and also shares the related personal thoughts.

Abstract:Take an example of application of CMS method in deep foundation pit support project with shaped steel interpolated in Tianjin, combined with the actual construction effects and monitoring data, analysis is made on the CMS method about its characteristics and its application prospect in super deep foundation pit support in soft soil area of Tianjin.

Abstract:In long distance tunneling with large diameter air cushion slurry balance shield machine under different geological conditions, different degrees of wear on shield machine cutter will be produced; especially in sand and gravel based formation, the formation with excessive level of quartz and soft & hard formation, the cutter head and cutter are more easy to be worn. In order to ensure the safe use of shield machine cutter head, inspection and replacement of edge cutter and center cutter often should be done according to the different wear standards in the cabin with pressure. With an engineering case of cutter inspection/replacement in cabin with pressure for river channel construction, the paper summed up the construction technology of cutter inspection/replacement in cabin with pressure for large diameter shield.