Abstract:Drilling construction was difficult in Qinghai Yemaquan mine, diamond bits were replaced frequently during exploration, which caused low bit service life, long construction period and high cost. All these were due to the unclear drillability in the mine and the adopted diamond bits did not adapt to the drilled strata. By the on-site survey, rock sampling and the indoor test, including thin section analysis and XRD test, the quartz content, grain size of quartz, feldspar content and feldspar granularity etc. were obtained to determine the rock drillabiligy. Based on these data, the diamond bits were selected. The outdoor test results show that the selected diamond bits work well with high performance- price ratio.

Abstract:Nitrogen drilling is to use nitrogen as circulating medium to cool the drill bit and carry out cuttings, which is generally used for efficiency improvement in deep well drilling or reservoir drilling. There are the characteristics of low porosity-permeability, low abundance and low production in middle-shallow reservoir of Daqing oilfield, mining by the conventional drilling process will result in reservoir damage and greatly reduce the output of crude oil. The paper introduces the application of nitrogen drilling technology, diesel dilution and screen pipe completion in middle-shallow reservoir of Daqing oilfield. Based on the field tests and exploration in 4 wells, the support technologies have been formed for drilling and completion in middle-shallow reservoir of Daqing oilfield. The analysis on the site application effect shows the feasibility and importance of nitrogen drilling in middle-shallow reservoir mining of Daqing oilfield.

Abstract:In the deep drilling construction of ZK96-5 which is the first deep drilling of rock gold exploration in China, SYZX wire-line coring hydraulic hammer was used with its advantages to increase the footage per round, improve drilling efficiency and prolong bit service life in the complex broken formation; and improve drilling speed and reduce auxiliary time in the complete formation. The newest record is created with the present hole depth of 3911.34m. The paper analyzes and sums up the advantages and common problems of wire-line coring hydraulic hammer in deep drilling.

Abstract:In Haoyaoerhudong gold deposit of Inner Mongolia, the intensive silicified formation is complicated with hard, brittle, broken and weathered broken stratum of sandy shale. By conventional rotary drilling, “slipping”, borehole upward inclining, core plugging, less footage round, frequent fishing, short net drilling time and low efficiency often occur. These difficult problems are overcome by wire-line coring hydro-hammer with good effects.

Abstract:According the problems of natural gas hydrates drilling fluid refrigeration system in the using process, such as improper manual operation, system paralysis caused by some abnormal factors of the equipment and frequent manual switching on and off of refrigeration cryogenic medium circulating pump, the intelligent temperature control unit was added based on the original system to improve the automation degree of drilling fluid refrigeration system for natural gas hydrates. The important hidden dangers of the refrigeration process are solved to ensure the normal process of drilling fluid refrigeration.

Abstract:With the construction case of a bedrock well in an iron ore mine of Gansun, which was 310 mm in diameter and constructed by foam DTH hammer, the paper summed up and verified the application of foam DTH hammer technology in large diameter bedrock well construction and presents drilling technologies in different borehole sections.

Abstract:Well Gucheng-7 is the first drilling well in Tadong block of Daqing oilfield. To increase the success rate of drilling, shorten drilling period and reduce drilling cost, a lot of calculation, statistical analysis and screening were made on the designs of well structure, BHA, bit optimization and the application of torsion impact apparatus in combination with PDC bits, the real drilling speed was greatly improved. The average penetration rate was 4.68m/h, 55.48% higher than that in well Gucheng-6 of 3.01m/h; drilling cycle is 152.44d, 86.8d less than well Gucheng-6. The practice shows that the design of well Gucheng-7 is consistent with the geological conditions in Tadong block with large improvement of drilling speed, short drilling period and low drilling cost.

Abstract:Soft erosion strata are often encountered in drilling construction; the cracked and soft rocks usually are eroded by slurry before entering the inner tube or drop out from inner tube because of unstuck core lifter. The low core recovery often results to borehole abandoned. The paper analyzes the causes of low core recovery in soft erosion stratum by an example of bauxite mines in Guizhou, an advanced side spray wire-line coring tool without pump is developed to ensure the core recovery with good effects.

Abstract:The paper analyzes the formation characteristics in Ashele mining area of Xinjiang and sums up the deep drilling experiences in hole structure and drilling tool grading, drilling equipment selection, drilling technology, wall protection and shut-off technology as well as drilling deviation control technology in Ashele area. According to the complicated broken formations, hole circulation loss and serious deflection-promoting in strata, the relative technical measures are presented.

Abstract:This article introduces the special application of drilling deviation correcting and deflecting techniques in dealing with drilling troubles in Songta hydropower station. The deviation correcting technology was used to ensure hole verticality when drilling construction was obstacled by casing deflection caused by uneven hardness in deep overburden riverbed; the deflecting technology was used to eliminate the effects casused by drill rod burying to keep drilling construction going on. These techniques have worked well in the drilling in deep overburden and broken layers and have development and application values.

Abstract:Compared with the traditional core drilling technology by lifting bits, wire-line coring technology can effectively solve the technical difficulties of poor core quality, borehole bending and downhole accidents. According to the drilling technology of hole-forming for curtain at the elevation of 940m on the left bank of Dagangshan hydropower station, the problems in drilling construction are analyzed and effectively solved by process improvement and optimization, the engineering quality is improved with economic benefits.

Abstract:Low drilling efficiency was caused by large friction and high torque in drilling and casing running process in middle-long and long horizontal wells in Daquing oilfield and the borehole wall collapsing led by long time contact with drilling fluid further slowed down the construction speed. The stimulation was made to rationally design the well trajectory according to different profile types, build-up rates and frontal distances to hitting target to reduce the friction and torque in drilling and casing running process and provide technical support for the smooth construction of middle-long and long horizontal wells.

Abstract:The heart of the screw drill (also called positive displacement motor, PDM) is the rotor, it decides the work efficiency and performance of the screw drill. In this paper, the influence of different slurry solid content and additive on rotor surface wear was studied, and a special testing set was made to stimulate the rotor surface wearing rule under real downhole working conditions. The rotor wear regularity under different mud conditions was explored, which was further studied. It is found that the solid particle and salty additives are the main reasons for hard chromium coating damage and identifies that the main form of hard chromium coating damage is corrosive wear. Some suggestions are presented to the rotor manufacturing process and the application.

Abstract:The variation rules of granite dynamic tensile mechanical properties are summed up, which are under the conditions of being cooled under different high temperatures, different loading rates and random fracture development; according to the process of down-hole rock cracking by roller bits, analysis is made on the curve of loading-fracturing depth under the coupling dynamic and static loads, the loading point of coupling dynamic and static loads should be at unloading stage of static load. Fracturing depth and volume of rock mass under dynamic and static loads are discussed based on the different pressure values, it is indicated that the efficient rock fragmentation and crack development could be carried out through enhancing static load and impact force, preloading static pressure to make pre-stress damage on rock and loading unloading loading fracturing circular mode. By the rock-socket pile foundation engineering practice, it is showed that by optimizing the structure and teeth arrangement, applying dynamic and static loading mode and cooling treatment of bit, the roller bit can realize high efficiency drilling in slightly weathered granite, which provides import technical support for the application of roller bit in rotary drilling bored piles construction.

Abstract:The paper introduces the rotator of a new vertical shaft drilling rig and the feeding device about the structure characteristics, technical parameters and the application in the project construction site. The products absorb the advantages of full hydraulic power head both in China and abroad with the features of long travel distance and easy maintenance.

Abstract:The paper briefly introduces the main difficult points and technical measures for the construction of φ3m anti-slide pile in Meiziping town of Guandi reservoir, which can be the important references to the similar large diameter pile foundation construction.

Abstract:In a treatment of high filling slope, it was difficult for hole construction with traditional methods, driving anchor tube method was adopted, which is well adapted to soil layers. Based on the numerical stimulation analysis on the reinforcement mechanism of high filling slope by driving anchor tube, the stress, displacement and plastic district are analyzed, finally the specific construction technology of driving anchor tube was given, which could be the reference for similar engineering.

Abstract:In the foundation pit engineering for an office building of BMW Brilliance in Shenyang, the excavation was pit in the foundation pit with depth of 10.4m and local excavation depth 6.05 to 7.4m, and the adjacent buildings surrounding around. Row piles and rotary jet grouting pile water-stop curtain were adopted as retaining structure and dewatering method to control the deformation. The selection of supporting scheme and the analysis on the construction effects could be the reference to the design and construction of the similar project.

Abstract:The internal bracing with two reinforced concrete lines was used in the foundation pit of a new ward building in Henan Province. The monitoring was made on the deep horizontal displacement of foundation pit retaining pile, strut axial force, ground subsidence and the settlement of surrounding buildings, the monitoring results under all the conditions were analyzed to find out the factors affecting the deformation of foundation pit and the regularity under different conditions, some instructive conclusions are obtained, which could be the reference to the similar engineering construction.

Abstract:In the deep foundation pit supporting engineering, the composite soil nailing wall with cement mixing pile-soil nailing wall and pre-stressed anchor was adopted. The paper introduces the main points of construction technology and the actual effects.

Abstract:In a project of backfill collapsible loess foundation in the Northeast, some regional soil collapsibility was not completely eliminated. Analysis is made on the influencing factors on effective reinforcement depth by dynamic compaction method in backfill collapsible loess foundation, the first influencing factors are determined to be the consolidation energy and one-shot points, and the soil moisture content, the thickness and distribution of different soils, compaction rate and the dynamic compaction design factors should also be considered.

Abstract:The paper analyzes the causes of settlement cracks in Datong-Hohhot expressway and introduces the measures for subgrade treatment with high pressure jet grouting technology. The practice shows that with this technology, the treatment construction can safely carried out with normal traffic remaining.