Abstract:The national groundwater monitoring well construction project is established and applied by Ministry of Land and Resources of the People's Republic of China and Ministry of Water Resources of the People’s Republic of China, which is approved by National Development and Reform Commission with the experience of feasibility study and evaluation for more than 10 years. With over 2 billion yuan of the total financial investment, the project covers 31 provinces and Xinjiang Production & Construction Corps including 7 large basins and 16 important hydrogeological units with 20401 groundwater monitoring sites. The organization and implementation of the project is of great significance, which is related to the livelihood issues of geological environment, drink water safety, economic and social sustainable development and so on. In this project, the drilling engineering determines the quantity, running effects and service life of national groundwater monitoring wells. In view of the characteristics of wide geolgraphical distribution, long construction lines and complex geological conditions of the project, this paper analyzes the key points of construction management, well construction design, pipe for well completion and drilling technology selection with detailed suggestions.

Abstract:The drilling construction situation of large angle inclined hole in Zara golden deposit in Eritrea is introduced. The practice and exploration are carried out on the requirements of hole deviation control technology, hole wall protection and plugging in complex formation, drilling efficiency improvement in slipping formation and some more drilling technologies. Rational configuration of bottom-hole assembly, washing fluid using technology, drilling parameter selection and bits selection are demonstrated. The exploration process and construction experience will be the foundation of similar projects in the future.

Abstract:Gas Hydrate Drilling Technology and Application Research in Wu-li Qinghai South Permafrost Region/LI Xiao-yang, ZHANG Yong-qin, SUN Jian-hua, LIANG Jian, WANG Han-bao, LI Xin-miao, WU Ji-xiu, LI Kuan, YIN Hao (The Institute of Exploration Techniques, CAGS, Langfang Hebei 065000, China) Abstract: Based on the introduction of the present situation of exploration and development of permafrost gas hydrates in the world and aiming at exploration requirements of gas hydrate in permafrost region of southern Qinghai, the hole structure of TK-2 is designed and large diameter wire-line coring and mud cooling technologies are used. Moreover, the problems of hole enlarging caused by permafrost melting and mud-cover in the inner wall of drill stem are emphatically discussed with effective solutions being adopted. The field experiment shows that key technologies of TK-2 are feasible. The meterage per rig-month is 702.07 m, the average core recovery rate reaches 93.5% and core bubbling and combustion-supporting are found at the depth of 229～234m.

Abstract:Tianjin area is rich in geothermal resources and oil and gas resources. In 1990s, Dagang Oilfield Co., Ltd. built a large number of exploited wells for oil prospecting in Tanggu area. With the oil resource exhausting, most of the wells have been abandoned. Combined with geothermal geological datas and oil well configurations, the methods of transforming abandoned oil wells into geothermal wells is explored in this paper, the feasibility is proved through the successful transformation examples of T38-1 and T38-2 wells.

Abstract:In order to improve the gas drainage hole drilling depth and the extracting effect, based on composite slag discharging technology with medium air pressure (0.7～1.2MPa), the field test was carried out by using screw drilling tool assembly with different specifications matched with corresponding process parameters. Comparing the different application conditions, the best bottom hole assembly and the matching technologies were selected to achieve high-efficient long borehole construction in whole coal seam.

Abstract:The hole wall stability and the flushing fluid leakage are important affecting factors for drilling efficiency and quality in drilling process. The more complex in the hole conditions, the longer the construction cycle and the higher the requirements on flushing fluid will be. The tectonic development is complicated in the construction area in Zaili of South Jiangxi, there are a large amount of loose and poor cemented sandstone, kaoline, chlorite and other water sensitive formations; borehole shrinkage easily occur; the hole wall stability is poor with spalling, block falling and collapse. The test was made on low solid dispersion flushing fluid, good drilling effects were achieved.

Abstract:Strong water sensitive and broken formation was encountered in drilling construction in Liba gold mine of Southern Gansu, drilling by ordinary wire-line coring tool resulted in low core recovery and low drilling efficiency, the average core recovery rate was 86.5%, the footage per run was below 1 meter, the minimum was only 20～30cm and the average footage per team was about 5 meters. Good drilling efficiency has been achieved by using SYZX96 wire-line coring hydro-hammer, the average core recovery rate, average footage per run and average machine efficiency per month have been improved by 8%, 50% and 17.5% respectively; drilling time increased to about 60%. Based on the application situation, the paper elaborates SYZX96 wire-line coring hydro-hammer about its structure, working principle and the points for attention in operation.

Abstract:Nowadays, building new reinforced concrete structures, repairing or reconstructing old structures are both important in China. To demolish and reconstruct a whole (or part of) reinforced concrete structure, conventional methods of mechanical disruption and blasting demolition have disadvantages of low construction efficiency, big potential security risk and serious environmental pollution. However, the construction method of static cutting demolition by employing diamond tools has developed rapidly in recent years. The most commonly used diamond tools include thin-wall diamond core bit, diamond saw blade and diamond wire saw. The application status, drilling and sawing mechanisms, manufacture technologies, as well as the construction parameters of the above mentioned 3 kinds of diamond tools employed in repair and reconstruction of steel concrete structure are summarized and analyzed in this paper, on the basis of this, the possible research trends and development directions are obtained. The research findings can provide technical reference value for wide application of diamond tools in civil engineering and some special fields.

Abstract:Because of the low automation level of traditional diamond drill sintering machine in China, it is difficult to flexibly deal with the requirements of diamond bits of different formula in hot pressing process, temperature and pressure. A new hot-pressing intelligent sintering machine for diamond bit is developed. It integrates optical, electricity and hydraulic pressure, taking the microcontroller as the core device of the control system and using fuzzy PID control theory to monitor and control the sintering temperature and pressure in real time to achieve prestoring process automatic operation, the control effect meets the needing of bit sintering process. The paper analyzes the influence of the working principle, temperature and pressure parameters of this hot-pressing sintering machine on the quality of finished bits and introduces its control system design matched with hot press.

Abstract:With the increasing investment of resources exploration and development in China, a large amount of full hydraulic truck mounted rigs are put into the drilling production. SDC-2500 full hydraulic truck mounted rig has been developed by CNIET, on which the load-sensing hydraulic system and PLC electronic control system are applied in the control and execution system with the characteristics of high integration, strong mobility, full hydraulic top driving, remote control and alternative-process adaptability. In the field production test, the rig shows its high mechanization and reliability.

Abstract:Sampling is required anywhere at anytime in the geologic survey and reconnaissance stage, it is necessary to develop portable sampling drill with the characteristics of convenient relocation, high efficiency and high quality. This paper introduces TGQ knapsack sampling drill about its parameters, features and the related tests. With the characteristics of small size, light weight, high and low gear speeds by reasonable structure design, the rig can realize diamond drilling and auger boring, take core in inclined hole and take sample in complex stratum. The drilling tools are made of high strength materials and rapid plug-in type connecting structure is used on drilling rod, the efficiency of drill pipe screwing on and off is improved. The development of this drilling rig has broken the monopoly of foreign products in Chinese market.

Abstract:Liquid-jet hammer have been successfully used in oil and gas drilling production for its high penetration rate and unlimited drilling depth. However, the damage of the bi-stable fluidic amplifier caused by complex stress has limited the working life of the liquid-jet hammer. In order to improving the performance of the liquid-jet hammer, the distribution of stresses in the bi-stable fluidic amplifier was studied by computation and the optimized structures of the bi-stable fluidic amplifier were proposed. Computational study results show that the optimized bi-stable fluidic amplifier can reduce the maximum stress one order of magnitude to improve stress situation obviously with longer service life.

Abstract:Taking Fuchun River pipe jacking engineering as an example, this paper introduces a quick-detachable device for local damage on pipe section in deep buried pipe jacking tunnel, which has simple and compact structure and is easy to be assembled in the tunnel with circular cross-section. With the maximum tolerance of water pressure of 0.8MPa, this device can repair damaged pipe section less than 0.4m along the axis at 30~80m below the groundwater level by grouting in pipe jacking tunnel to effectively deal with small area local damage and small scale water leakage & sand gushing, and it can provide emergency repair supports for circular cross-section tunnel constructed with pipe jacking method.

Abstract:The paper mainly introduces CYG-300 type multifunctional full hydraulic drilling machine about its overall structure design and hydraulic system design as well as main function. The load feedback system is adopted with dynamic head double hydraulic motors and two-gear manual transmission to output 4 different stepless torques and rotating speeds; related control valve is set for feeding circuit in hydraulic system to increase rotary spray function of the machine, all of these make the rig suitable for wider range with more functions. The field test drilling shows that this hydraulic system has good operation condition, strong drilling ability and convenient operation.

Abstract:The drilling pressure control model was established based on the structural characters of full hydraulic driving head ground coalbed gas drilling rig, feed mechanism mathematical models and drilling pressure control experience formulae; the fuzzy PID controller was designed and simulation analysis was carried out. By adjusting the coefficients value of threshold pressure value and rock drillability value, the influence of the different strata and the parameters of controlled objects in drilling courses on auto-drilling system were simulated and the simulation analysis indicates that this system has good adaptability and anti-interference ability with high response speed and small overshoot. Therefore, it is feasible to realize constant drilling pressure by fuzzy control, which has guiding value for automation and intelligent control of drilling machine.

Abstract:The directional drilling technology with MWD system used in underground is one of the important means for exploration of hidden geological factors causing disasters in coal mine. Compared with the conventional drilling technology, directional drilling technology has the advantages of precise trajectory control, broad branches coverage, calculation of coordinates and some others. In order to test the accuracy of the measurement results of the new MWD system, a field experiment was carried out in the well and 2 testing holes were drilled. The results show that the accuracy of new MWD system is excellent, the real drilling deviation can be kept in the allowable range of 5‰ of the borehole depth and can provide accurate three-dimensional coordinate parameters to meet the requirements of accurate exploration of hidden geological factors causing disasters in coal mine.

Abstract:Casing is commonly used for wall protection in quaternary loose strata drilling and pulled out after completing construction. But it is easily to be stuck by attachments from the outside, pulling out is difficult. A casing stuck releasing device was developed to loose the outside wedged attachments for casing unfreezing and pulling out. This device has been used in boreholes with desired effect.

Abstract:This article describes a case of deep foundation pit construction for Huangpulu sewage treatment plant, which was by Yangtze River with complex geological conditions. The paper points out the harm of groundwater in the construction of deep foundation pit and discusses the methods and the major points of treatment. Dewatering is inevitable in the process of deep foundation water treatment but peripheral settlement can be avoided. With reasonable treatment scheme, ensured well quality and standard-operation, the construction requirements on dry operation can be reached.

Abstract:Foundation pit dewatering is one of the key links in the excavation for building construction by the riverside and is an important factor affecting the construction period and the construction quality of the whole project. The paper introduces the design and implementation process of groundwater treatment for the ultra-deep foundation pit of a high-rise building by Songhuajiang. The selection of the design parameters in the construction process, the construction experience and deficiency are discussed and summarized, which can be reference to the subsequent construction.

Abstract:The traditional support structure of double-row piles single portal frame is a frequently used supporting design for foundation pit in soft soil area because of the advantages of simple construction without inner support, small investment and space saving. But for super-large foundation pit of medium excavating depth in soft soil, large lateral displacement and settlement as well as poor structure stability often appear. Combined with the improvement on the traditional support structure of portal frame, double portal frame support structure without inner support was proposed in a large medium-depth excavation project in soft soil to further improve the overall safety and stability and control the lateral displacement of the supporting structure. The applicability and feasibility of this improved design are verified through a basement foundation pit supporting project in Shaoxing County, which provides valuable experience for the similar projects in the future.

Abstract:Based on a rock slope blasting project in a scenic spot, a relevant blasting design scheme is proposed for solving the harmful effects caused by controlled blasting of rock slope in complex urban environment. Weak loose directional controlled blasting was combined with shallow-hole urban blasting and pre-splitting blasting in this scheme. The blasting design parameters of each design are presented with corresponding detonating circuit and sequence as well as charge structure. Through the strict implementation of this scheme, the vibration damage by blasting is greatly reduced and the actual blasting construction effects meet the desired objectives. This design can be reference for similar projects.