Abstract:The well inclination is difficult to control for high steep structure CBM drilling, and such reservoir spreads extensively and has a huge potential in China. According to the conditions of coal seam structure in Huolinhe basin, coalbed methane with large inclination, large thickness and high permeability is classic low coal rank and is easy to implement the process of drilling and extraction with U-shape slant well. This technology is to build a kind of special fluid circulatory system in coal seam by intersection of directional deviated well and a vertical well. Annular gas under-balanced drilling technology has been adopted in the drilling course in order to protect coal seam. Screw pump with large delivery capacity, low cost and strong sand resisting should be selected to improve production efficiency. U-shape slant well can take full advantages of fluid potential of coal seam and every well and improve efficiency of dewatering and gas producing.The paper discussed the drilling and completing technology of U-shape coalbed methane well and gas production technology according to the drilling and extraction in Huolinhe.

Abstract:By the analogy analysis on the comparison among sodium slurry, calcium slurry and other solid-free washing fluids, it was proved that sodium slurry had the mechanism for good drilling effect in complex formation of tin mining area. With this successful experience, suggestion was made on laying stress on study and application of sodium slurry.

Abstract:Some unforeseen downhole troubles often occur in the drilling course for various reasons， dealing with these troubles would waste a lot of time and cost much money. The paper introduces a new technology which can accurately forecast the downhole troubles ahead of time. Analysis was made on the variation of drilling parameters in drilling process by real time analysis with time series method, and according to the variation curves, the downhole troubles could be predicted. An application case and the remedial measures were elaborated. The study indicates that this new technology can reliably forecast downhole troubles 100~200 minutes ahead of time to greatly reduce the economic losses.

Abstract:Based on the logging data of the drilled holes, analysis and calculation were made on the formation pore pressure, formation fracture pressure and borehole collapsing pressure in main blocks of the Hailaer oilfield; the sectional drawing was also established for pressure change of wells in different blocks and pressure change of wells in the same block but with different depth. According to the analysis, accurate predictive value of formation pressure could be obtained by acoustic time difference method. The fracture pressure was calculated by Eaton mode, Steve mode, Huangrongzun mode and well log data; the comparison proved the predictive data of fracture pressure by Huangrongzun mode was accurate and the collapsing pressure calculated by Mohr-Column rule could satisfy the project precision requirement. Reasonable and safe drilling mud destiny window was eventually determined for different blocks by comprehensive consideration.

Abstract:In Tarim oilfield of Hudson area, drilling efficiency has been restricted mainly because of the existing micro fractures and joints in Permian igneous rock. According to this drilling difficulty, strong sealing inhibitor was tested for optimization in laboratory. The experiment showed the polysulphonate drilling fluid has good rheology, low filter loss and strong inhibition.

Abstract:The paper introduced the wall protection and leakage control technical measures for drilling in the complex formation of Haobugao mining area. According to the rock formation and the hole depth, wall protection and leakage control by casing, flushing fluid and cement sealing were adopted with good effect. Casing was safe and reliable, manual sodium soil low-solid mud has high inhibition function to downhole collapsing and block-falling, and cement has good sealing effect. Casing and cementing created favorable conditions for wire-line coring drilling with solid free drilling fluid and improved drilling efficiency.

Abstract:The quaternary and tertiary strata of Pingshanhu mining area are water encounter unstable with serious clay invasion and high borehole expansion rate while drilling; and all these result in frequent drilling accidents and low drilling efficiency. The application test was made on non-dispersed low solid-phase drilling fluid system with polymer as main additives, clay invasion and shale hydration swelling were effectively inhibited.

Abstract:The paper analyzed the causes of drill burying accident in 25-2 borehole of South Sichuan coalfield, introduced the treatment process and the technical measures, and summed up the experience.

Abstract:Based on the drilling construction in Yaozhuang coalmine of Henan, treatment measures for downhole water gushing, well cementing, coring and hard formation drilling were detailed for future drilling construction.

Abstract:As a new type of pipe material for well completion, PVC-U pipe has been widely applied in water well construction abroad but is still in promotion stage in China. By the economic comparative analysis on PVC-U pipe and traditional metal case in well completion, it shows that PVC-U pipe is more economical in the pipe material cost, well completion hour and construction process.

Abstract:The screw pile is a new type pile with high bearing capacity, low cost, high construction efficiency and non-pollution. The newly developed LGZ-25 full hydraulic screw drilling rig satisfies the special technological requirement of screw pile. The paper introduced the drilling rig about its structure, technical parameters, working principle and the application effect.

Abstract:By the large diameter rocksocket boredgrouting pile project in the construction of Beijing-Shanghai highspeed railway, the SH25H hydraulic pneumatic impact drill was trial manufactured with the pneumatic DTH and positive circulation rotary drilling technology, and chip removal was carried by bailing bucket. A new method for dry borehole drilling was explored and summarized with high drilling efficiency and high quality of borehole.

Abstract:The paper introduced the shaft verticality control technology for shaft of mine (in the diameter of 8.3 m and depth of 286 m) constructed with mechanical drilling method, such as the key technical measures of increasing the weight of large diameter drilling tool, installing the drilling director and measuring the shaft verticality.

Abstract:Incomplete casing, case breaking, drilling rod cementing and case collapsing often occur in the construction of large diameter coal mine gas emission well, ice transmission cooling-well, nitrogen injection well and feeding well in China in recent years. The paper analyzed the failure causes according to the study on common accident of large diameter project well, and put forward the prevention measures.

Abstract:This text elaborated the advantages of diaphragm wall with triad structure compared to the traditional one and introduced a few key links of strict control while diaphragm wall as “function structure”. Application effect and trend prospect in the actual engineering were also discussed.

Abstract:The monitoring of the deep soil horizontal displacements is very important in the excavation process. Based on the monitoring on the deep soil horizontal displacement in Yuhuan, the paper discussed the dynamic change of the displacement. The monitoring result shows that deep soil horizontal displacement usually happened near the orifice or 3 m below it; soil horizontal displacement situation of each hole was in safety range and tended to be stable. The foundation pit was effectively guaranteed by the information feedback to the construction according to the analysis study on the foundation pit monitoring effect.

Abstract:The paper introduced the application and effect of bored occlusive pile in foundation pit support. By the engineering case, bored occlusive pile construction technology and technical measures were described. It was proved that the bored occlusive pile had good effect in strength, verticality, integrity and water prevention for medium sized foundation pit support structure.

Abstract:The paper briefly related the characteristics of polymer slurry based on the analysis on the wall protection mechanism of polymer slurry. Preparation, recycling, purification and discharging method of polymer slurry were summed up, and the layout of slurry circulation system was optimized. According to the engineering practice, some rotary drilling problems necessary to pay attention and the treatment methods were pointed out.

Abstract:Taking the example of Meipu reservoir reinforcement project of Yun Country and combining with the practical engineering geology and the design of plastic concrete cut-off wall, the paper introduced the application of plastic concrete cut-off wall made by hydraulic grab in reservoir reinforcement about construction programs, construction technology, construction difficulties and countermeasures, construction processes and the quality control.

Abstract:In order to make clear the karst cave distribution beneath roadbed at Yesanguan section of 318 national highway, GPR was used for delineating. By the analysis on the stability of the karst disturbed zone, the jet grouting method was chosen for the reinforcement. The strengthening region was detected again, and the effect is very significant.

Abstract:With the engineering case, the paper discussed the construction process of collapsible loess foundation treatment with deep dynamic compaction pile in borehole and the effect.

Abstract:The characteristic of wireline coring drilling in deep hard formation is that there is a contradiction of bit pressure increasing limited by bit slipping. Based on the successful experience of the extra-deep well construction of Taigou iron mine, the paper put forward the technical measures of impregnated diamond bit selection and application for improving drilling efficiency and prolong bit service life to solve bit slipping in deep hard formation drilling.

Abstract:Shield construction is widely used in the urban metro; the urban metro generally has the characteristics such as small engineering quantity, short mileage, multi stations and a large number of turning around, etc. Station-passing plays an important role in the construction. Shield generally has a narrow space and various processes, so the reasonable shield station-passing can not only save manpower and material resource, but also can ensure the engineering quality. Based on the engineering practice, the shield station-passing construction technology has been deeply studied in this paper.