Abstract:Under the background of “the Chinese continental scientific drilling project location and drilling test” in China, the article reviews and summarizes the great achievements and problems of drilling engineering of Russia СГ-3 ultra deep well. Based on the rethinking on the experience and lessons, some issues are discussed, which should be paid attention in future ultradeep scientific drilling project in China, such as scientific target and engineering management, scientific location selection, well deviation control and new drilling achievements, the related conclusion are presented.

Abstract:The paper introduces the situation of the calculation of core recovery percent by RC drilling in China. The calculation methods for weight recovery percent and volume recovery percent are discussed and the comparison is made on their advantages and disadvantages. The volume percent is suggested to be as the quality assessment index.

Abstract:The occurrence is steep with ore concentrating in Chengjiagou-Shagou silver polymetallic ore deposit. Because drilling designs are mostly branch holes with medium depth and large slope, the borehole quality is the key technology. By the construction case of 1550m inclined hole, the paper introduces the selection of medium-depth inclined hole drilling technology and the concrete measures for ensuring drilling hole curvature.

Abstract:According to the granite formations of deep wells and ultra-deep drilling, through the measurement of the longitudinal wave velocity after the granite heating and conventional tri-axial compression tests, and based on the experimental results, the study is made on the longitudinal wave velocities of granite by different temperatures heating and macro mechanical properties under tri-axial compression stat. The analysis is made on the relationship between the granite longitudinal wave velocity, peak stress, elastic modulus, peak strain and the temperature; at the same time, the granite macroscopic failure form under the condition of tri-axial compression are summarized. The results show that, after heating and cooling, granite longitudinal wave velocity is decreasing with increasing temperature; meanwhile, under a constant confining pressure, when the temperature changes from 20℃ to 200℃, the peak stress, elastic modulus, peak strain tended to increase with the temperature increasing, but when the temperature changes from 200℃ to 400℃, these mechanical parameters is decreasing. Temperatures can make the water content of rock gradually decreases, and because of different thermal expansion of rock internal mineral compositions, the additional thermal stress inside the rocks is generated, thereby the initial crack inside the rock will have propagation and coalescence or new cracks generate to affect the stability of the borehole wall and the surrounding rock.

Abstract:In the deep formation below Changling fault Quantou group, because of the increasingly higher rock drillability grade, low ROP and long drilling period, drilling speed improvement becomes the key problem in this area. The high rotating speed and high torque of turbo drilling can improve the rock breaking efficiency by high rotating speed and high torque, but it has a certain limitation. By the analysis on the speed-up of turbo drilling in the well Tushen 1, turbo drilling has good speed-up effect in fault Denglouku formation, but it isn’t fit to the Yingcheng group tuff formation.

Abstract:Daniudi is an oil and gas reservoir with low pressure, low permeability and low abundance, whether the optimized fast drilling is in put in use become the main factors restricting the development of horizontal wells. Through the statistical analysis on the well structure, BHA, bit selection and the drilling mud system, an optimized fast drilling technology is summarized, which is suitable for Daniudi gas field and can substantially improve the drilling speed and shorten the drilling cycle.

Abstract:Based on the analysis on the accident causes and omens of metal objects in the drilling hole bottom, a new type of magnetic fishing tool was developed, by which metal objects in the drilling hole bottom can be efficiently fished with good effects in engineering application. The paper introduces this new type of magnetic fishing tool about its design ideas, structure principle, operation technology and the field application effects.

Abstract:The paper summarized the research actuality and application fields both in China and abroad. The design structure, specification and key techniques of QHZ-2000 casing rotator are elaborated. The paper analyzes the structure principle and the application characteristics of casing string, hammer grab and drilling tools for underground obstacles removal; and also summarizes the construction process, mechanism and applicable scope of full casing cast-in-place pile, underground obstacles removal and pile extraction in full casing. This study fills the gap of independent research and development of casing rotator in China; it is environmental, universal and safe piling equipment and a new foundation drilling method with no mud used in urban construction and foundation works.

Abstract:Impact rotary compacting drilling is a kind of advanced soil anchor hole forming method, two-way pneumatic DTH hammer is the main equipment used for it. Its critical device is two-way pneumatic impact mechanism; the gas distribution stroke design is related to the DTH hammer conventional working performance and realization of effective reverse impact. Based on the analysis on DTH hammer gas distribution theory, using section calculation method and finite difference principle, the study was made on the design of gas distribution stroke length of two-way pneumatic impact mechanism and put forward the design reference value of gas distribution stroke length ratio.

Abstract:In the construction of deep exploration and scientific drilling, the reasonable selection and using of drill bit is one of key factors to improve the deep-hole drilling efficiency in the hard, brittle, crushed rock. Based on the analysis on the special rocks in Jinchuan scientific drilling and study on the distribution, holding and exposure of diamond in the bit by scanning electron microscope, the appropriate matrix materials for bit and diamond process parameters are found to prolong the service life of the diamond bit and improve the drilling efficiency.

Abstract:High RPM and large pressure drilling parameters were usually adopted in the exploration drilling in Yemaquan mine of Qinghai. Since too much cuttings and heat are produced in the unit drilling time, the early failure of diamond bit is often caused by the abnormal wearing, and the construction schedule is seriously affected. The diamond bit was designed and the matrix formula and manufacturing technology were improved based on the geological and technical conditions in the field, the water outlet is appropriate widened. The results of numerical modeling analysis and field test show that the cutting removing, temperature and diamond bit service life are effectively improved.

Abstract:The computational fluid dynamics (CFD) method is employed for numerical simulating the flow field in the bit which can be opened and closed with large via. Analysis was made on the speed field under different flow conditions, the optimum drilling air volume is acquired and the “obstruction vortex” is found in the flow field. And through the analysis on the pressure field under the optimal flow conditions, the existence of “suction pressure difference” is found in the flow field. The influence mechanism of “obstruction vortex” and “suction pressure difference” to the heat dissipation and slag discharge is realized, which can be the references to the optimized design of the bit and will lay a foundation for the popularization and application of the technology of gas drainage with screen pipe protection for the whole borehole in soft outburst coal seam.

Abstract:According to the slope collapse and rock falling in a tunnel of coal special railway line in Huangling mining company, the control plan was put forward by concrete spraying and pre-stressed cable frame beam to prevent the further weathering of the rock surface and the mountain collapse. The control construction was carried out based on the design the paper introduces the control plan design and the main points of the construction.

Abstract:It is very difficult to the construct large diameter anti-slide pile in hard rock mass, the safe and effective structure design and reasonable selection of construction methods are necessary. Taking a case of foundation pit supporting engineering, with innovative supporting structure scheme, using micro steel pipe piles instead of large pile in hard rocks, and these improved technology effectively overcame the difficulties in large diameter rock-socketed pile construction and met the requirements of original design to achieve the supporting effect.

Abstract:Because of the rich water content and high water level, the safety would be influenced in the foundation pit construction for a building in Nanyang City and the main difficulty was dewatering. The construction safety was ensured depending on the strict foundation pit support and dewatering scheme. The paper introduces the application of the design of shotcrete & rock bolt support and dewatering as well as the construction process.

Abstract:According to the collapse, borehole diameter shrinkage, slip of drill bit, large thickness of sediment in the bottom appeared in a viaduct project in soft soil layer with rotating drilling rig, the accident causes were analyzed; and casing lengthening, bit structure improving, drilling process optimizing, borehole cleaning by air-lift reverse circulation and slurry purifying methods, etc. were adopted with good effects. The construction experiences could be reference to the similar projects.

Abstract:In order to investigate the dynamic compaction effects under 2 different backfills of hill-skill soil and fine sand in soft ground, the field comparative tests were made in the same littoral area. The results of standard penetration test (SPT) before and after dynamic compaction and the shallow plate loading test were analyzed; and the comparative tests were also conducted. Based on the conclusion, the suggestions are put forward to further improve the foundation treatment effects after dynamic compaction.

Abstract:Combining with the on-water exploration engineering example of Wuhu Yangtze river highway bridge，the paper summarizes the construction technology and construction safety management in deep and rushing river section. With the existing conditions, effective technical measures were adopted mainly according to the accurate anchoring and positioning of drilling platform; protecting casing fixation; bending, deformation and fracture of protecting hole casing; fluctuation of the water level and casing expansion, the drilling cost was greatly reduced and the good economic benefit and social benefit were obtained.

Abstract:According to the comprehensive problem of large slope and small radius curve in the construction of a shield interval of Tianjin metro line 3, by the use of variety of data accumulated in the construction process, with the stress analysis and mathematical statistics, the analysis is made on the influence of the variety of data to shield tunneling, and the discussion is made on the shield tunneling operation and rectification technology. It is realized that the correct analysis on the thrust force and direction, the articulated structure and correction curve setting in the special curve segment is the focus for shield operation and rectification in large slope and small radius curve segment.