Abstract:Scientific drilling hole NLDS-1 in Ganzhou is one of the 6 boreholes in the pre-research project on the location for CCSD. Because of the complex formations and serious natural bending, the wire-line core drilling was used with high viscosity and high density mud and the drilling trajectory was manually controlled for this borehole. The paper introduces the hole construction technology and innovation achievements, summarizes the experiences in the construction process and expounds the understandings from the technology in deep drilling.

Abstract:Based on three-dimensional fast Lagrangian finite difference method of fluid-solid coupling theory of porous medium and elasto-plastic limit equilibrium theory, according to the QK-2 well drilling data of gas hydrate drilling test well in Qiangtang basin, the analysis is made on the mechanism of borehole instability under the condition of seepage and the numerical simulation analysis is also made on the wall stability of instable section to learn stress distribution of surrounding rock around the well and deformation laws of borehole collapse or crack in different drilling fluid density. The safe density window of drilling fluid is determined for no formation collapse (diameter reducing) and no leakage for the gas hydrates drilling test well in Qiangtang basin, so as to provide the evidences for the determination of casing program design and reasonable drilling fluid density.

Abstract:With the case of 2000m deep drilling in Hadamangou Inner Mongolia, the paper summarizes the difficult problems encountered in the construction and the related technical measures to be taken; introduces the selection of flushing fluid and the preparation, selection of 3 drilling parameters and the study on technical measures.

Abstract:The gold orebody shows cylindrical output with small section area in Jinchang mining area of Heilongjiang Province, the location deviation is common for the densive borehole distribution. The directional drilling technology is introduced to control the drilling trajectory, which improves drilling efficiency and develops branch holes to learn the morphology of ore body. The paper introduces some affecting elements and the technical measures in the application of directional drilling.

Abstract:Almost all the drilling contractors accomplish inverse well construction with mechanical raise boring machine, but it usually works inefficiently. Engineers in CNIET have developed a fast and safe process to drill inverse wells by adopting SDC1500 all hydraulic truck-mounted rig matched with new cluster inverse well pneumatic DTH to solve the inefficiency. This construction process is summed up with the case of large diameter drainage well in a coal mine of Inner Mongolia.

Abstract:In the crisis mine deep exploration drilling, abandoned tunnels are inevitable encountered, which bring many difficulties for the normal construction. In this case, the use of reverse reaming technology and casing in the tunnel will receive good effect. The reverse reaming tools are designed to solve the sealing of circulation medium under high pump pressure; the geological designing purpose is realized with rapid and economic one-time crossing tunnel.

Abstract:No circulation media core drilling and auger drilling were used for the bauxite prospecting in Bokai of Guinea. The engineering practice and the comparison test show that no circulation media core drilling has disadvantages of low efficiency, high cost, unstable core quality and high labor intensity in weathering residual formations; but with auger drilling technology, the drilling quality of design requirement by specification can be satisfied with lower cost and higher drilling efficiency, the drilling efficiency is 6.77 times that of core drilling and the comprehensive construction efficiency is 3.5 times that of the core drilling.

Abstract:In view of the high viscosity of drilling fluid, difficult pipe tripping and hard control of drilling fluid rheology in a highly deviated well of a block in Liaodong Bay, a new technical method is put forward that starting from cuttings bed removing, on the basis of the improvement of mud cake quality to ensure a smooth borehole, stable borehole wall and effective cuttings carrying, the rheology of drilling fluid is controlled to be turbulence at the drill collar so as to the cuttings uniformly dispersing in the drilling fluid to reduce the formation of cuttings bed. In this block of Liaodong Bay, this technology is used in 8 wells with the horizontal distance and vertical distance ratio of less than 2, the ideal effects are obtained.

Abstract:The drilling trajectory can be precisely controlled by directional drilling technology to meet the requirements of geological structural exploration in Hudi coal mine. Four quasi-directional drilling boreholes has been constructed by ZDY6000LD directional drilling rig to accurately prospect coal seam strikes in main and auxiliary transport cross-hole, which provides a basis for coal mining, extraction and digging. The paper introduces the design basis of the directional geological structural exploration hole in Hudi coal mine and the drilling technology.

Abstract:Because of the poor drillability, dense lithology and local high gravel content in Denglouku formation, Yingcheng formation, Shahezi formation and Huoshiling formation in Lishu fault block; and rock hardness is up to Grade 7. Low drilling efficiency and short service life of cone bit were the difficulties for traditional drilling technology, and the drilling effect was not ideal for PDC bit trial. But with turbodrilling technology, the average ROP increases 4 times, the drilling cycle is shortened and the comprehensive drilling cost is greatly reduced. The practice shows that turbodrill impregnated diamond drilling technology is effective with high abrasive, high compressive strength and speeding up for drilling in high temperature deep well.

Abstract:In coastal prospecting drilling, the positioning control is difficult in both horizontal and vertical orientation because of the waves, tide, currents, winds and other factors of instability, which can be solved by pontoon platform steel pipe pile sleeve expansion joint method. The paper introduces the compound application of sleeve expansion joint and positioning steel pipe pile in coastal wire-line core drilling by the engineering practice.

Abstract:Due to the soft and broken characteristics of soft and outburst coal seam, the gas drainage borehole easily collapses with low borehole completion rate and the blockage of gas drainage channel, which influence the efficiency of gas extraction. The open-closed reverse circulation bit was designed in order to solve these problems, and its working principle and structure characteristics were also analyzed. The advantages of full screen liner and reverse circulation drilling technology are combined with this bit, by reducing the second damage to the hole wall to improve the borehole completion rate and depth, by sending the full screen liner to the hole bottom to avoid wall collapse and gas drainage channel blockage, the utilization rate of the gas drainage borehole is increased. The paper introduces this new bit about its configuration design, working principle and the application.

Abstract:To prevent the accidents caused by unclear geological conditions and ensure the construction safety at mining face, preliminary geological exploration should be done. The originally used underground drilling machine could ont satisfy the need of preliminary geological exploration because of the small power and difficult relocation. Taking ZDY1200S full hydraulic underground drilling machine as a prototype, the design of hydraulic system and main components are optimized to meet the application requirements of preliminary geological exploration. The field test proves the good effect.

Abstract:With the continuous development of the geothermal well construction in recent years, the demand of casing for geothermal well is also increasing steadily. Because the construction cost of geothermal well using oil casing keeps growing, it is urgent to develop a special casing for geothermal well to adapt the needs of geothermal well construction with low cost. According to the characteristics of the geothermal well construction and the performance requirements to the casing, a low-cost casing for thermal well is developed. The paper mainly introduces this casing about its structure form, technical parameters, process equipment and production application.

Abstract:CSM Method, that is double wheel milling deep mixing technology, is a new type of technology. A good job of the cement soil quality control and the related preparation work should be done to ensure the construction quality of CSM method before the construction. In construction process, the trenching verticality, cement in cement slurry, water cement ratio and grouting volume, milling drilling speed and double wheel revolution, overlapping length and quality of structural steel inserting must be under control.

Abstract:The application history of foundation treatment technology is reviewed, which is roughly divided into 4 categories, namely consolidation method, replacement cushion method, grouting reinforcement method and composite foundation method. The reinforcing mechanisms, construction technology, strengthening advantages for all kinds of optimization technology in foundation treatment are summed up. This paper introduces the engineering application of these foundation treatment technologies and the direction of future research; states the development trend of optimization technology for foundation treatment in China.

Abstract:The paper introduces the engineering design and technical scheme of pressure grouting before the construction of the second auxiliary shaft and the east ventilation shaft of Zhangji coal mine. Y-shape branch holes were constructed with directional drilling by MWD to improve the construction efficiency of grouting hole and avoid interference from the site. Repeated grouting and grouting with pressure control were used to solve the mud channeling in fractured formation and protect the roadways nearby. The related issues in the engineering design and the construction are systematically summarized and discussed.

Abstract:The row piles internal bracing system is commonly used in soft-soil area for foundation excavation retaining and protection. This paper analyzes the key factors in the design and construction, which affect the stability of this system. And based on a failure case of foundation pit engineering, the typical instability causes in row piles internal bracing are discussed with treatment countermeasures put forward. The excavation results show that the treatment is effective and safe.

Abstract:The original stress sate of the formation is destroyed in the shield tunneling construction. Formation stress increment, especially shear stress increment, will cause ground movement and result in ground settlement in different degree. If construction parameters are not in proper control in super large diameter slurry shield tunneling, too serious ground settlement will affect the safety and usage of ground construction. The summarization is made on a dyke-crossing construction project by large diameter slurry balance shield in Nanjing, which can be taken as reference to the similar construction.