Abstract:There are a lot of drilling technologies and methods in the world，among them coiled tubing drilling is an important oil and gas drilling technique, particularly for gas drilling. It has been used widely in USA, Canada, and also in Russia, leading to good technical and economical results. There are such coiled tubing units in China, and they are used. In Russia steel wire armored polymer coiled tubing has been developed and its technical characteristics are as good as those of carbon-steel coiled tubing. The designed hydraulic feed device has eliminated the problems such as high drag force, low penetration rate while drilling long horizontal wells. Combining of the armored polymer coiled tubing with the feed device creates favorable conditions for promoting the application of the technology. It can be expected that this technology may make contributions to development of coal gas and shale gas drilling in China, and has definite practical significance. It is worthy for us to pay attention to.

Abstract:Based on the introduction of the development and application status of BeiDou Navigation Satellite System (BDS) in China, and taking into account of the characteristics and requirements of field construction, operation and maintenance management and data security of geological exploration equipment, this paper proposes the overall conception and technical framework of the BDS application in geological exploration equipment through integration of mobile communication, internet, broadband satellite communication and other technologies. The paper also describes in detail the spectrum planning and the application platform development scheme of BeiDou application terminal products for drilling equipment and geophysical prospecting instruments, which can work as guidance and reference for better application of BDS in geological exploration equipment.

Abstract:In order to meet the increasing demand for bored piles with 3m diameter and complete the series sizes of full hydraulic percussive reverse circulation drilling rig, YCJF-30 full hydraulic percussive reverse circulation drilling rig with the nominal drilling diameter of 3m was developed. The mechanical, electrical and hydraulic technology is integrated into the YCJF-30 drilling rig, with the unique hydraulic cylinder for impact, the differential double-drum hoist for increasing lifting ability, and the heavier 20t impact hammer for high rock-breaking efficiency. The drilling rig is equipped with hydraulic step-walk crawlers, which can be conveniently shifted to align with the well collar. The drilling tower is controlled by hydraulic cylinders, which are stable, safe and labor-saving. Furthermore, air-lift or pump reverse circulation can be adopted to discharge drilling cuttings with high carrying ability. The production test showed that the drilling rig has reasonable and advanced parameters, reliable performance, high degree of automation, simple operation, easy maintenance, low cost, and can be used for drilling of various formation.

Abstract:Rock vibrates when the bit breaks rock. In order to study the influence of rock characteristics on rock vibration during drilling, a vibration-based rock identification method is proposed. Rock vibration equations are established on vibration theory and elastic mechanics, and numerical simulation software is used to analyze the influence of different parameters on rock vibration. Research shows that rock vibrates under the impact load, and rock properties are closely related to vibration; the density, rigidity and compressive strength of rock has a certain effect on rock vibration, and the rock strength has the most obvious effect; the smaller the rock rigidity, the lower the strength. The rock vibrates more under the impact load. Studying the vibration characteristics of rock during impact drilling is of great significance for drilling parameter setting and lithology identification.

Abstract:The Zhunnan Coalfield Mining Area in Urumqi is the key area of coalbed methane exploration in Xinjiang Region. Compared with conventional cluster wells, horizontal wells have been used more and more in coalbed methane exploration due to its benefits of low cost and good yield-increasing effect. However, the Urumqi Mining Area has the characteristics of high dip and complex structured target coal seams. So it is necessary to optimize and adapt the horizontal well drilling technology to the local geological characteristics. In light of the horizontal well construction characteristics, research has been conducted on wellbore instability mechanism, low harm drilling fluid systems, and the optimization design of wellbore structure; and field tests were carried out with good effects.

Abstract:Fuling Shale Gas Field was the first marine shale gas field put into commercial exploitation. It went through the development evaluation test phase in 2013 years, and the Phase I productivity construction from 2013 to 2015 with development of a series of drilling and completion technology ideal for Fuling Shale Gas Field exploration and exploitation through field test and application. In the second phase, greater buried depth, and formation uncertainty led to great obstacles in increasing the drilling speed; particularly the bit type selection was difficult for some complex formation. It was mainly reflected in the low drilling rate per round trip with conventional bits, multiple times of tripping, and difficult orientation. With the analysis of drillability and directional difficulties, 121/4in high abrasive hybrid drill bits were selected for strong abrasive and alternating sand and mudstone in the Xiaoheba Formation of Pingqiao Block. In order to solve the serious problem of directional drag force in drilling of the second section in long reach three-dimensional wells, 121/4in high-efficiency directional hybrid bits were optimized. In view of the characteristics of high formation deflection rate and strong abrasiveness in the build section of Longmaxi Formation (containing turbidite sandstone), the 81/2in hard formation directional hybrid bit was optimized. Up to now, the three types of hybrid drill bits have been used in the Fuling work area for more than 200 times totally, with an average reduction of 4 to 5 trips and cutting short of the drilling duration by 6～7 days. The selection of the hybrid bit has provided technical guarantee for the drilling acceleration and efficiency improvement in the second construction phase, and also provides the bit selection scheme for the efficient development of the following shale gas fields.

Abstract:In recent years, the small-diameter coring technology has been widely used in oil and gas exploration. Incidents often happen in the hole during drilling, such as frequent wellbore overcut, large displacement due to high deviation at the bottom of the hole, unstable drilling fluid performance. The small-diameter coring technique was used to drill the geological survey hole of Well Tongdi-1 for oil and gas, and it was successfully completed with all drilling indicators meeting the geological design requirements through optimizing drilling parameters, properly determining the drilling structure, and adopting effective measures to prevent hole deviation.

Abstract:The main part of the Hunan Baojing shale gas exploration block is located in Baojing County of Western Hunan. It is a favorable zone for exploration and development of shale gas, but high risk and challenge are present due to complicated geological conditions, deep buried reservoir, large formation dip change, poor drillability, long drilling period and high drilling cost. Before drilling started, the formation pressure and rock compressive strength was obtained by processing and analyzing the existing data of seismic, logging and core experiments. The well structure and drill bit selection were optimized. In the drilling operation, the drilling tool assembly, mud system and cementing technology were optimized according to the characteristics of the formation. The high efficiency bit was adopted with the MWD tool and long-run core barrel to carry out compound drilling, well deviation prevention, and fast drilling. In order to improve the drilling speed and efficiency in shale gas, and reduce the drilling cost, a new 70 MPa liner hanger and liner cementing technology were adopted to ensure the overall sealing, and cementing quality of the casing string, which provided guarantee for the following fracturing treatment.

Abstract:The upper overburden in the northern mining belt of Xiaoqinling is quaternary sediments with thickness from 700 to 950m. Malignant incidents such as bit sticking, bit burial, hole caving often happen in drilling, and even result in the scrapping of the drilling hole, which seriously restricts drilling efficiency, leading to high drilling cost. In view of these technical difficulties, technical analysis and research were carried out. Through optimizing the borehole structure, adopting the wireline core drilling method suitable for the thick overburden in the mining area, properly choosing the drilling fluid with good borehole wall protection, and other technical measures, the difficulty in drilling the thick overburden was solved; meanwhile, the drilling efficiency and quality were improved, and the drilling cost was reduced.

Abstract:The high position directional borehole is a key technical measure for gas control in the upper corner. In view of the need for gas control of roof cracks in Qinglong Coal Mine and the difficulty in drilling high position directional boreholes in the complex roof, the technical principle and technical advantages of high position directional boreholes are expounded. Based on the theory of “three zones”, the horizons of high position directional boreholes are determined, and the drilling tool combination and drilling parameters are optimized. At the No. 11615 working face of Qinglong Coal Mine, five high position directional boreholes were completed in the roof with the maximum hole depth at 612m, the maximum gas flow rate of the single hole at 2.79m3/min, and the gas concentration up to 23.4%, which effectively ensured mining at the working face.

Abstract:In view of the grave influence on surrounding buildings due to the design and construction process of the Tongyu Yangguang Haoting foundation pit support project, some measures were taken to ensure the smooth progress of the project, such as optimization of the construction process and construction sequence according to the stratum and surrounding environment, adoption of jet grout expanded anchor cables, change of the support pile drilling and rebar cage lowering methods, local adoption of the SMW method, intensification of monitoring during construction. The construction experience can be used as a reference for similar projects in the future.

Abstract:Firstly, through orthogonal experiment, this paper optimizes the fusion scheme for seamless connection of the Revit model for the foundation pit supporting structure and the Civil real three-dimensional geological model; thus, solving the difficulty for Revit to directly create the real three-dimensional geological model at present. On the basis of this scheme, a series of fine modeling methods for common supporting structures of foundation pits such as pile, anchor, surface and layer are explored and summarized. Finally, in the context of actual project cases, the preliminary application research of the comprehensive model for supporting structures of foundation pits under the BIM concept is carried out in the field of computer aided design: three-dimensional concretization and roaming display, collision check of supporting structures and the surrounding underground precast piles, accurate calculation of work quantity, design optimization of space intersection joints of different supporting structures, sectional observation of the three-dimensional spatial attitudes of the groundwater table, the poor weathered bedrock surface and the silt layer, the two-dimensional CAD supporting pile position plan which can be used to guide accurate measurement and setting-out, etc.

Abstract:During hoisting of the pipeline in horizontal directional drilling, the hoisting point on the pipeline determines the entry angle into ground. If the entry angle is too large or too small, it may cause either sticking or collapse of the pipeline. Through the simulating analysis for the influence of the entry angle and the lifting point during the lifting process, it is obtained that with the distance between the lifting point No.2 and the front end of the pipeline at 10m, when the entry angle is 10°, the allowable space between the two lifting points is 22～28m; when the entry angle is 12°, the allowable space between the two lifting points is 28～36m; when the entry angle is 14°, the allowable space between the two lifting points is 30～36m. In such a way, the pipeline is in a safe state during the lifting process. When the entry angle exceeds 16°, the pipeline stress exceeds its yield stress; thus, the entry angle should not exceed 16°.

Abstract:The excavation depth of the No.3 shaft on the Zhenhe to Jianhe Water Diverting Project in Xin’an County was large, where groundwater was extremely rich with water gushing and flooding. Slim pilot pipe grouting was taken to seal off seepage and gushing within 2 times the shaft diameter of the gushing point with a dual fluid made of cement and sodium silicate mortar. With grouting before excavation, the tunnel excavation was successfully completed, which can provide experience for the construction of similar projects.

Abstract:Plasma blasting technology is a new type of blasting technology. The design of blasting holes plays a decisive role in the overall blasting effect and blasting efficiency. In this paper, the finite element model is established for the blasting hole based on ANSYS/LS-DYNA. The numerical simulation of the wall pressure and the fracture zone of the undercut holes under blasting loads is carried out. The results show that the distortion energy changes during blasting from beginning to end. It is basically elliptical; and the smaller the aperture, the larger the accumulated energy, and the greater the damage to the rock mass; the shorter the hole depth, the smaller the energy accumulation space, and the greater the damage caused by the blasting to the rock mass; The hole depth has less impact on the lower rock mass and has greater impact on the middle rock mass. In addition, since the explosion experiment is mostly a destructive one, it is difficult to carry out the prototype test. Therefore, it is feasible to use the numerical simulation method to study the structure of the blasthole, which can be used as a reference for field work.