Abstract:Well QTD-1 is a shale gas geological survey well drilled in Tongren, northeast Guizhou Province. A brief description of investigative techniques such as drilling, well logging, gas logging are given in this paper. Through core drilling, gas logging, well logging and field data interpretation, the regional lithologic units have also been verified, with some geological parameters of shale gas within the Niutitang Formation obtained, including the development characteristics of the black shale, the gas bearing capacity. In conclusion, the marine shale of the Niutitang Formation is the main gasbearing strata, and it is distributed extensively and stable in the investigated area. Generally, the gas content increases with the depth; the maximum value of the total hydrocarbon is 4%, the gas production within the broken zone of the core is over 2600mL, and the maximum value of the field gas bearing capacity is 1.97m3/t. All these characteristics indicate a large gas capacity, and show a good prospect for the exploration and development of the shale gas in Tongren area.

Abstract:In order to further reduce the drilling difficulty of infill adjustment wells in the Fuling Shale Gas Field， as well as improve the drilling speed， research on infill well trajectories optimization design has been carried out in regard to the geological characteristics of the shale gas field. The 3D trajectory design for shale gas drilling mainly includes three types：“fivepoint sixsection” trajectory， “sixsection with the circular arc in the inclined plane” trajectory and “dual2D” trajectory. The optimized “circular arc in the inclined plane” 3D trajectory is determined to be more suitable for horizontal well design in the Fuling Shale Gas Field by comparison of the indicators such as the length of directional section， drag force， torque. To optimize the parameters of the 3D trajectory design with circular arc in the inclined plane， a case study has been conducted on trajectory optimization design for a 3D horizontal well with the kick off point and buildup rate optimized through comparison of drag force and torque at different kick off points and buildup rates to find out the minimum drag force and torque. It can provide reference for the infill well trajectory optimization design in the Fuling Shale Gas Field．

Abstract:As a national energy base， the Ningdong area of Ningxia has deployed and implemented a large number of core drilling projects in recent years， resulting in a large amount of waste drilling fluid. Because the disposal method of waste drlling fluid was relatively simple， it has brought some damage and impact on the surrounding environment. Through investigation and research on the treatment methods of waste drilling fluid in the Ningdong area， the solidification method was finally selected to treat waste drilling fluid. The produced waste water and solidified substance meet the relevant national discharge standards. A set of disposal methods suitable for waste drilling fluid in similar areas has been developed， which is helpful to protect the fragile ecological environment in the Ningdong area．

Abstract:There are a lot of fractures， karst caves and fractures in the shallow strata in the Guizhong-Nanpanjiang region， thus causing serious lost circulation and borehole wall collapse. It was difficult for hole drilling with conventional mud protection. The simultaneous casing drilling process has been applied to large diameter shale gas well drilling for the first time， which effectively solved the drilling problem with the conductor hole. The practical application of the process in the Qianshuidi-1 well is systematically summarized and can serve as valuable reference for similar projects in the future．

Abstract:In Liuyangbao Gas Field， lost return leakage generally occurs in the horizontal well during running casing through the horizontal section. This is mainly reflected in the fact that drilling slurry will not return out of the well when casing is set from 2800 to 3100m， though staged circulation is adopted. In the field， casing was directly run to the bottom of the well， and then the normal injection and reverse squeeze displacement method was used to establish circulation to ensure normal cementing. The method has solved effectively the problem of lost circulation in casing cementing， and provides solution for the similar situation in other blocks．

Abstract:The Songnan volcanic rock stratum has strong abrasiveness and poor drillability, leading to low drilling rates and long drilling periods. With the continuous advancement of exploration and development, the pore pressure of volcanic fractured reservoirs decreases gradually. At present, the development well type is mainly horizontal wells, where drilling rates are restricted due to acute circulation loss. In view of this problem, this paper describes the geological characteristics and the drilling difficulty with evaluation and optimization of the existing technology in regard to the progress on drilling technology for the Songnan volcanic rock in recent years. The measures and recommendations are presented for increase of the drilling rate in subsequent drilling in the region on the basis of field application results.

Abstract:Drilling parameters and operations are often guided by data shown at surface devices during drilling process. However， some of these data are different from real downhole parameters. The deeper the borehole， the bigger the difference; and it is true with deep drilling， particularly super deep drilling. As a result， it will influence improvement of technical and economical indexes of well drilling. Here we introduce the research results from Russian peers who deeply investigated on remote measurement and automatic control system of borehole bottom parameters such as drilling fluid pressure， azimuth， inclination， axial weight on bit. They also proposed some frameworks on how to perform these measurements and control operations. In China， deep earth exploration strategy has been initiated and a 13000m ultra-deep well is under planning. The design approach and execution plan for these systems discussed here can provide beneficial reference for downhole parameter measurement and automatic control during super deep well drilling of China in the near future.

Abstract:The ultrahigh temperature drilling trajectory measurement instrument is a new type of storage inclinometer system specially developed for drilling trajectory measurement in high temperature environment，with the vacuum flask as the main means of insulation from high temperature environment, since the vacuum flask has a large length/diameter ratio with the internal effective use length up to 2.0m. In order to understand the law of temperature rise in the axial direction of the vacuum flask when the external environment temperature is fixed, and provide a basis for the reasonable arrangement of the probe tube structure, this experimental study has been conducted. Through the laboratory test of two vacuum flasks, the internal temperature rise value of the vacuum flasks in different ambient temperatures was obtained. Through the analysis of the measured data, the internal temperature rise law of the vacuum flasks was found to include three main aspects: first, the temperature rise value is basically linear with time, and the temperature rise rate increases with the ambient temperature; second, the temperature rise value is a function of the ambient temperature in a cubic curve; third, the internal temperature rise value of the vacuum flask gradually decreases from both ends toward the middle, and the temperature rise value of the middle part is significantly lower than that of the two ends. Based on the test results, the layout of the probe tube structure has been rationalized with specific measures taken to ensure that the working temperature index of the instrument meets the specified requirements. The test results can also provide a reference for the structural layout of other similar hightemperature instruments.

Abstract:Efficient, economical and environmentfriendly defoaming technology is the basis for achievement of foam drilling fluid recycling. A novel rotary and spray type of foam breaker was designed according to the gas ejector principle by which compressed air was used as the power medium combined with vacuum negative pressure, impact shear, aerated saturation and pressure diffusion for quick defoaming and foam fluid recycling. The computational fluid dynamics software FLUENT was employed to simulate the flow characteristics inside the foam breaker. The simulation results showed that the rotary and spray type of foam breaker generated two adjacent overlapping vacuum negative pressure areas inside and can produce great suction force on the outside flow with the suction amount about 1.6 times the compressed air at the inlet. The maximum negative pressure can reach 21kPa inside of the foam breaker when the mass flowrate of the compressed air flow at the inlet was 0.1kg/s, generating a larger area of negative pressure near the collision point of multiple jets from the converging nozzles due to jet speed boost which is conducive to defoaming.

Abstract:This paper discusses the design approach for the vertical antislide structure of the anchor cable and pilewall combination through theoretical analysis of the Bishop strip method based on limit equilibrium theory， selection of the sliding surface of the slope by use of the Lizheng Rock Soil design software and stability analysis and calculation of the residual downsliding force in the context of the slope support project for a road under construction in the logistics port area of Liudong New District of Liuzhou City， where the elevation difference of the slope caused by the design and construction of road cutting is about 35m high. Combination of the pile crosssection size and rebars is conducted under the bearing capacity limit conditions; meanwhile， the slope surface treatment， protection and drainage scheme above the vertical support structure are also introduced. It may provide reference for the high slope support and treatment projects in road construction in the future

Abstract:This paper introduces the structure， main features and application of Geoprobe7822DT， Geoprobe 8040DT and Geoprobe 3230DT direct push soil drilling rigs， and compares them with other types of similar sampling rigs. Analysis is conducted on their inadequacies in quicksand sampling such as insufficient wall protection， poor overall stability， and easy drill pipe damage with suggestions put forward for further improvement and use of the direct push soil drilling rigs．

Abstract:In this paper， taking the bedrock slope of Wanshan Geological and Cultural Industrial Park as an example， the stability of the slope is calculated and evaluated quantitatively by the combination of stereographic projection method and Sarma method， it is concluded that the high and steep rock slope is in an unstable state. Two methods are used to calculate and confirm each other， which provides an important basis for the design and construction of the slope in the next stage， and has a good reference for similar projects．

Abstract:In reference to the geological structure and formation characteristics of Western Sichuan， the paper establishes the profile of the formation strength and rock mechanics parameters according to the well history data and logging data， and derives the distribution rule which shows general high rock strength and drillability and consistency of the change trend with the elastic modulus， cohesion， and internal friction angle. The mechanical parameters reach the maximum at 2500 to 2700m deep formation， while the poissons ratio decreases to the minimum. The bit evaluation and optimization method based on the theory of rock mechanics properties and the mechanical specific energy theory is proposed with the mechanical specific energy of the bit concluded for each section of formation. The performance of the bit which has been used is also evaluated， and it is found the PDC bit performance is not satisfactory. As a result， a bit recommendation which puts priority to the rock bit and the impregnated bit is presented to provide guidance for drilling speed design for the work area．

Abstract:The differential tensioning method can effectively improve the tensioning efficiency of the prestressed anchor cable with pressure dispersion, which has been successfully applied in the slope reinforcement for the drain building of Lianghekou Hydropower Station. In order to ensure the balanced load of the steel strand when tension reaches 110% of the design load, the differential compensation load is calculated and analyzed, and it is found that the difference generated in the pretightening stage is key to balanced load. The single differential compensation and the overall tension stage are briefly introduced and analyzed.

Abstract:During construction of the underground diaphragm wall for a pipe gallery in Chaoyang District, Beijing, the antiseepage treatment measures with sleeve valve pipe grouting were adopted to save the cost and reduce the influence of water seepage at the joint on waterproof construction for the subsequent structure due to limitations of the geoengineering and hydrogeological conditions, construction site, and other factors. This paper introduces the construction method with the sleeve valve pipe grouting process, and has verified that the antiseepage measures with the process in dealing with the flexible joint of the diaphragm wall are completely feasible.