Abstract:Hydraulic cavitation jet technology is widely used in petroleum drilling for its safety and reliabiligy with good effects. According to the conditions of poor drillability and low ROP in lower part of medium hard limestone formation of Y oil field in Iran, hydraulic cavitation jet tools are tested. By the study on the formation strength of test oil field and the drillability parameters, hydraulic pulsed cavitation jet device and BHA were selected; the mechanical and hydraulic parameters have been optimized. The real drilling data indicate the obvious improvement of hydraulic cavitation jet drilling tool, which is good for drilling in medium hard limestone formation.

Abstract:Since the Rotary magnetic ranging system (RMRS) of America Vector Co. is introduced in CBM horizontal butted wells field, major breakthrough was made in the construction technology of directional butted wells both in CBM and solution mining industries in China. However, most application is still limited in U-shaped well group composed of a vertical well and a horizontal well. In a project of Huajin coking coal Co., DS well group is a coal-bed methane well group composed of 2 horizontal wells, by the target guidance system “Huici” which is made in China, “point to point” is realized. The paper introduced the technical methods of accurate “point to point” target construction.

Abstract:In the halite resources survey project in Cang County of Hebei Province, the construction cost was high because it was difficult in coring and wall protection by mud. In the first borehole, Qingshen-98-Ⅱ double tube core barrel, carbide scraper, PDC bit and coring by drill string lifting were selected for coring operation. The construction efficiency was improved by critical drilling time and core plugging prevention; wall stability was ensured by sectional wall protection with mud.

Abstract:High altitude, short frost-free period and about 20m thick permafrost at 4000m above sea level are the characteristics in Qinghai area, where drilling is difficult because of the influence of flushing fluid and heat produced by high-speed rotary friction of drill pipe. Formation dissolution and collapsing occurred in the process of ice melting, and in addition to difficult polymer dissolution at low temperature, the rheology performance is affected. By improving the drilling tool joints and optimizing drilling fluid performance, construction difficulties were solved. The paper introduces the improvement of s and the flushing fluid technology.

Abstract:According to the tectonic development in a molybdenum mining area of Inner Mongolia with complex geological conditions of hard formation, broken core, borehole diameter shrinkage, leakage, collapsing and block falling, the technical experiences of drilling construction for wire-line coring in hard, brittle and broken formations were summed up. Analysis was made on borehole structure, mud configuration, flush fluid selection, drilling equipment and new SYZX75 2 ( 77) type wire-line coring hydro-hammer drilling tool to solves the leakage, collapsing, block falling and drilling difficulties in hard “skid” formations. The paper emphatically elaborates the high strength dehydration blocking test, which can improve drilling conditions in complex formations and drilling production efficiency to ensure the drilling safety.

Abstract:By selecting the suitable equipments and reasonable drilling parameters, good application effects were obtained by air reverse circulation continuous sampling drilling process in Wushi phosphorus vanadium mine of Xinjiang. The practice shows that this technology can get 100% sample recovery even in arid area and difficult sample recovery formation with low construction cost and effective economic benefits. The paper introduces the construction equipments, pipe configuration and drilling technology.

Abstract:For DZS1 well of freshwater resources investigation project in Zhoushan sea, the drilling was started at water depth of 15 meters. The full hole coring depth reaches 202.1 meters by drilling in overburden layer mainly with clay and sand layers and 2 meters of weathered bedrock. In the quaternary, 127mm drill pipe was directly used for wire-line hammer collision coring drilling without casing; in bedrock, 50mm drill pipe was used for swivel type double tube coring drilling with 127mm drill pipe as casing. The paper introduces the main construction processes and quality control methods, including anchor of drill ship, consideration of tide impact on drilling pipe，control of drilling procedure, hole cleaning, drill bit replacement，mud technology and so on.

Abstract:According to the treatment of drill rod burying accident in the hydro-geological hole reaming in Dandong of Liaoning Province, the paper analyzes the causes of drill rod burying, introduces the treatment method and summed up the prevention measures with suggestions.

Abstract:The rock in Dulanggou mine is hard and dense with the characteristics of weak abrasiveness and high drillability. The drilling efficiency and footage are low with large amount of auxiliary work and long drilling cycle in the earlier-stage construction. By using TXY75 wire-line coring hydraulic impactor technology, drilling “slip” was effectively overcome, drilling efficiency and footage were improved with less core plugging, reduced auxiliary time and higher efficient net drilling time.

Abstract:Because of the extremely thick water sensitive weathered layer in Yaoyu gold mine, collapsing and block-falling occurred frequently in drilling process, and the common wall protection measures were not effective to deal with the accidents. ZK604 was completed by experimental application of PAB non-dispersion polymer mud and potassium polymer mud. The paper introduces the difficulties and the relative mud technologies in the drilling construction of this mine.

Abstract:The paper introduces the LXZJ4000 crawler underground drill about its development background and general structure placement design; respectively describes the drill about the functions of main parts, structure features, working principles, the tests and the application.

Abstract:According to the requirements of the strength and MWD communication to the drill pipe for the directional drilling technology, center cable drill pipe is used to realize real-time MWD signal transmission; and the high strength pipe, special screw thread structure, friction welding technology are adopted to improve the tensile, compression, bending and torsional strength of pipe. The necessary solutions are introduced based on the existing problems in field operation. MWD examples in Dafosi mine, comb hole examples in Zhuxianzhuang mine and directional drilling examples in Hashatu mine respectively prove that the center cable drill pipe can meet the requirements of measuring communication and strength with the maximum hole depth of 1200m, the directional drilling with minimum bending radius of 54m and directional drilling in coal seam with inclined angle of 58.

Abstract:The necessity of multifunctional application of rotary drilling rig, the multifunctional design ideas and the schemes are discussed; each function configuration and the application are introduced. By the multifunctional design of rotary drilling rig, the use of rotary drilling rig can be greatly expanded, the purchase cost can be reduced and the quality of the bore-forming can be improved to meet the requirements of environmental protection.

Abstract:The Quaternary loose layer of Yangtze floodplain area is a huge thick and complex aquifer with rich groundwater, which has great influence on deep foundation pit engineering. This paper analyzes the characteristics of dewatering project for the foundation pit in Nanjing Meizizhou river-crossing tunnel project, dewatering designs were made for each segments, and proper dewatering well structure was selected based on the features of different segment, the aquifer above the excavation surface was dredged by whole hole filling filter material with good dewatering effect. Standby wells were prepared in the segments where there was big water level difference between inside and outside pit to prevent piping caused by the defect of enclosure, increase security for foundation pit and effectively protect the surrounding environment.

Abstract:By an engineering case of small diameter diamond drilling in Dagangshan hydropower station, the paper summarizes the construction technology of small diameter diamond drilling in hard formation. The description includes the choice of equipment machinery, construction technology, the determination of the relevant parameters, common problems in drilling and prevention measures. And analysis is made on the borehole deviation according to plane projection drilling track.

Abstract:According to the complex karst characteristics near No. 30 and 31 piers of the large bridge at Beijin-Fuzhou passenger dedicated line and by the repeated discussions, the foundation treatment plan was decided to take pre-reinforcement of dissolved cavity fillings by pressure grouting. The paper introduces the construction processes, attentions and late quality detection, which can be the reference to the similar engineering.

Abstract:Underwater concrete injection is the most important process in the construction of bored pile. There will be the phenomenon of tube rupture or collapse sometimes for the tremie in underwater concrete injection in ultra-deep hole. The direct reason why the phenomenon would happen was theoretically analyzed through stress analysis. Various factors which may cause tube rupture and collapse were listed based on the practice, and the corresponding preventive measures were put forward, which may be beneficial to the quality management of underwater concrete injection in ultra-deep hole.

Abstract:Bases on the traditional static blasting, a new technology of static blasting in large diameter borehole is presented; with a new reaming bit and mechanical hole plugging device, hole gushing of static blasting in large diameter borehole was solved. As the hole becoming larger, the expansion pressure increases and the reaction of cracking agent speeds up, these make plugging more difficult. Test of static blasting in large diameter borehole for block rock was made by newly designed reaming bit and hole plugging device, which proves the feasibility of this new technology with expected effects of improving the cracking ability and reducing the cracking time. It is a new way for rock blasting construction in sensitive areas.

Abstract:Wire-line coring drilling put forward higher requirements to the parameters of diamond bit. By the analysis on the influence of diamond bit performance to drilling operation, discussion was made on the manufacture and performance parameters of diamond bit to satisfy wire-line coring drilling in deep hole. The parameter indexes of new type of bit are suggested based on the advanced experiences both in China and abroad.

Abstract:Big field fluidity, complex working conditions and uncertain factors affecting safe construction bring dangers to geological prospecting activities. By the analysis methods of preliminary risk factors and working conditions risk analysis in safety system engineering, the paper discusses the variety of risks of geological drilling exploration activities at present and proposed universal feasible safety countermeasures.