Abstract:The trajectory of cycloid extended reach well consists of straight section-arc section-cycloid section-steady inclined section with the minimum or very small friction and friction moment. The design comes down to solution for system of two elements equations, when the unknown design parameters are according to the initial well deviation angle of cycloid section or deviation angle of remained inclined section, the equations are nonlinear without analytical solution. The equivalent triangle function equation is obtained by mathematical transformation and simplification; numerical iterative algorithm for triangle function equation approximate solution is put forward by interval query and bisection method. The numerical examples show the algorithm has high calculation accuracy and quick operation with good iterative stability. This new algorithm can be applied in the development of computer software to improve the applicability.

Abstract:According to geological characteristics and drilling difficulties in Haita district, drilling technical study and field test were made for drilling speed-rising plan. Technical difficulties caused by collapsing of upper-part formation, easy deviation in mid-part formation and hard bottom part formation were solved with the optimized and fast drilling realized. The paper analyzed the field application in borehole structural optimization, optical selection on drilling bit and parameters and compound drilling with the case of Xi 50-54 well, and it showed the great improvement on penetration rate and drilling period.

Abstract:Composite rapid solidification early strength agent was made by laboratory tests to improve the long cement curing time of wall protection for drilling in complex formation, which was applied in different mining types drilling as additive for cement wall protection and seepage control with short cement curing time, controllable setting duration and good quality.

Abstract:The paper introduced the application of SYZX96/75 wire-line coring hydro-hammer in complex formation with interbedding of soft and hard rocks in a gold mine of Hunan and summed up the construction experience. SYZX96/75 wireline coring hydrohammer was applied with the footage greatly increased and auxiliary time reduced, which played a key role in improving the coring effect in broken formation and reduced hole deviation.

Abstract:Wire-line coring drilling technology has been widely applied in drilling engineering, which can greatly improve the drilling efficiency and drilling quality in deep hole drilling. Based on the application research on deep hole wire-line coring drilling technology in Xiping iron mine, the paper discussed the importance of borehole structural optimization and suitable matching of drilling tool types, and also studied the key technologies of mud system and deviation control.

Abstract:The paper introduced the complex geological conditions in the encountered formation for deep hole construction in Hadamengou gold deposit zone and several drilling fluids with each applicability, and discussed attention points for medium-deep hole drilling and the importance of strengthening the construction management.

Abstract:Drilling pipe sticking accident occurred in HDR29D geothermal well, which was overcome by the accident cause analysis, stuck-releasing scheme study and stuck-pipe freeing agent compounding. The paper summed up the causes of drilling pipe sticking in directional well and the treatment method.

Abstract:The southwest edge of Erdos basin is an extreme water shortage area. There are many water wells in cretaceous water-bearing formation, but water quality degradation and water quantity decreasing are common phenomenon, which is mainly caused by the serious unreasonable well structure. Based on the analysis on the causes of water well quality degradation, the substantial issues was found that water quantity decreasing was caused by well structure deformation because of unreasonable water stoppage method and diameter shrinkage in mudstone. The scientific and reasonable well-forming scheme was put forward to solve the water well quality issue and prolong the water well service life.

Abstract:In the application of bridge filter in water supply pipe and geothermal well engineering, collapsing accident often occurs. The paper analyzed accident principles, types, characteristics and the influence factors with relevant preventive measures put forward to prevent and reduce the deforming and collapsing accident of bridge filter.

Abstract:The construction technology of the seismic monitoring well in Hebei was introduced about drilling technology， well pipe processing， pipe laying & cement injection and well pipe cleaning & water fetching. The cement injection around the pipe was applied correctly; the design demands were satisfied by this technology.

Abstract:Gas content can be effectively decreased by pressure injecting nitrogen with high fire retardancy nitrogen or liquid nitrogen to extruding and exhausting gas, and improve coal production security. As passage between the surface and the tunnel, nitrogen injection hole should be with large diameter, good verticality and channel protection property. The paper discussed the construction technology of large diameter nitrogen injecting hole with successful case.

Abstract:Rock drillability is the key for drilling efficiency， which reflects the fragmentation， and is the base for drilling model， type of drilling bit and drilling parameters designing. According to the calculation method of rock drillability and the logging data， the profiling of rock drillability is built， based on which, different types of drilling bit are suggested. The application results show that these drilling bits can increase penetration rate in the central part of Junggar Basin with guiding significance to bit selection for subsequent drilling.

Abstract:The paper introduced the newly developed test device of drill performance about the testing method, composition, testing bench, loading device, load controller and testing control system.

Abstract:Ultrathin flexible concrete seepage-proof wall construction method has many advantages in various underground seepage control projects. This technology was applied in the seepage control project of Pudong Liming landfill site reconstruction, which was the first case of the similar project in China. Based on this project case, discussion was made on the application of ultrathin flexible concrete seepage-proof wall construction method about construction technology and quality control, and some suggestions were also made on reasonable selection of seepage control technology.

Abstract:With the rapid development of urban economic construction, the project of urban underground space keeps increasing. Excavating and drilling adjacent to underground structures are usually encountered in engineering construction; especially for the large area and deep excavation method such as diaphragm retaining wall, which would affect original underground structures with safety and quality trouble. According to the engineering case, the paper introduced the application of diaphragm retaining wall in foundation pit near subway structures in Shanghai. By the feasibility analysis, the relevant controlling methods were adopted in the construction process to minimize the deformation effect to subway structures. The practice shows that diaphragm retaining wall is suitable for similar complex project.

Abstract:In long spiral CFG pipe construction, attention should be paid on pile position control, pile foundation construction, concrete quality, construction measures in winter, thickness of cushion and protection after pile-forming to avoid appearing quality problems. The experience summary and the discussion on above issues were made in this paper.

Abstract:The high pressure jet grouting method has advantages of wide application, easy construction, simple equipment and convenient management, which has been widely applied in foundation seepage control for hydraulic structure. According to the high pressure jet grouting construction in tailrace of Lingguan hydropower station, the paper introduced the problems encountered in the construction and the treatment measures to provide reference for the similar engineering.

Abstract:Foundation treatment is usually difficult for large water conservancy project on the mudstone which generally has poor geological conditions. The dam foundation of Hattashan hydro-junction project was constructed on flat mudstone; the stability and security of the dam foundation were seriously affected by the deep layered fracture zone. Analysis on the outgush infiltration channel was made and a series of grouting method were taken. This approach not only saves cost, but also ensures the construction quality. The article summed up the treatment method of special gushing water in the mudstone on the basis of the large water inrush in powerhouse water collecting well and in the P7 fracture zone; it is worth to be the reference.

Abstract:Analysis was made on the dynamic consolidation design, construction parameters and reinforcement effects by the application and successful experience of hydraulic fill sand foundation treatment with dynamic compaction method in Shougang Jingtang Caofeidian Steel United Company, which could be the reference for the similar projects.

Abstract:In the anchor support construction with large-tonnage and super-long hole depth, the borehole deviation control greatly influences the effect of pre-stressed cable anchorage. Based on the analysis on the causes of borehole inclination, the paper put forward the prevention and control measures for large depth anchorage cable hole.

Abstract:The Jinpingshan tunnel project is the key of Jinping hydropower complex, which is located in the high geo-stress area of south-west China with a whole length of about 17.5km and the maximum depth of the tunnel is about 2375m. The length of the section with buried depth over 1500m is about 12875m. The paper introduces the unique characteristics of the project and the comprehensive prevention construction technology by the analysis and study on the rock burst characteristics in Jinpingshan tunnel.