Abstract:This paper mainly studied the physical and mechanical properties and the breakdown pressure of oil shale in Wangqing of Jilin Province. Firstly, the physical and mechanical properties of oil shale were studied with DNS300 electronic universal testing machine and the range of these parameters was obtained by analysis. In the vertical bedding direction, the compressive strength of oil shale is 21～30MPa, the tensile strength is 1.1～3MPa, the elastic modulus is 7.1～9.9GPa, the Poisson’s ratio is 0.21～0.27 and the shear modulus is 3.4GPa. In the parallel bedding direction, the compressive strength is 13～17MPa, the tensile strength is 0.3～0.6MPa, the elastic modulus is 1.2～1.6GPa, the Poisson’s ratio is 0.31～0.36 and the shear modulus is 0.5GPa. According to the experiment results, the breakdown pressure of Wangqing oil shale was calculated theoretically by selecting the appropriate parameters. Then the hydraulic fracturing experiments of oil shale were carried out by using true tri-axial hydraulic fracturing device, the results show that the breakdown pressure of Wangqing oil shale is 5.34MPa. On the basis of the theoretical calculation and experiment results, it is suggested that the breakdown pressure of the hydraulic fracturing experiment in the site of Wangqing oil shale should be controlled in 4～6MPa.

Abstract:Flushing technology is an important link in drilling engineering. Circulation of flushing fliuid in the hole can clean hole bottom, cool drill bit, carry & suspend cuttings and protect the hole wall. Different flushing processes can produce different complicated situations. Due to the same direction of reverse circulation of flushing fluid at the bottom hole and the core entering into the core barrel, the quantity and quality of cores can be improved in the fissured, fractured, brittle and unequal hardness formations. Doctor KULIKOV V.V., who works in Moscow State Geological and Prospecting University in Russia, and some others have carried out a lot of scientific works in the hole flushing technology, present the classification table of compicated flushing situations in drilling process, analyze and discuss the flushing technology in geological drilling with commonly used drilling with no pump technology, jet core drill and air-lift core drill, and some correspongding suggetions are put forward.

Abstract:The conventional plain cement sealing material cannot fully meet the sealing requirements of the special geological formation with water gushing and gas bearing. Taking the sealing cement mortar as the research object, the proportion of cement mortar was designed by orthogonal experiment, the formula of the sealing material suitable for the water gushing and gas-bearing formation was obtained, and the technical requirements for borehole sealing quality are obtained. On the basis of laboratory experiments and combined with the specific formation conditions of Tongdi well1, the field application tests were carried out with the corresponding sealing material formula according to the sealing quality requirements of different well sections. The results show that the designed sealing material formula can meet the requirements of borehole sealing quality in the water gushing and gas-bearing formation.

Abstract:The deep copper-gold deposit in GUI Shan contains super thick weathered and fractured zone, severe collapse was encountered during drilling, which led to the difficulties of pipe tripping and hole cleaning. Therefore, the solid-free polyvinyl alcohol drilling fluid was used to enhance the collapse prevention ability.The experiment indicated that the higher the amount of polyethylene, the higher the viscosity of the drilling fluid, and the stronger the ability of stabilizing the core without disintegration. However, there is no obvious water loss-control ability. The use of FT342 can significantly reduce the water loss, and has good lubrication. This drilling fluid was used in drilling through the broken carbonaceous shale and coal seam during the section of 714～834m of ZK141 borehole, the scaling on the inner wall of drill pipe was solved with a good effect of preventing collapse.

Abstract:The geological conditions in the Guangdong Heyuan area are complex with well developed karst caverns and fissures. Drilling difficulties usually lead to serious circulation loss, long construction period and high cost. A new type of polymer gel plugging agent was developed to cope with the local formation with large size caverns and fractures. Theoretical analysis is made of the basic performance and the mechanism of the new type gel plugging agent, with lab experiments and field tests conducted on the gel forming time, load bearing capacity, breaking performance, etc. Comparative tests were done on different gel formula, resulting in an optimum make-up which was applied to plugging with good performace, such as reducing consumption of the drilling fluid, increasing the drilling efficiency. Application in the Guangdong Heyuan area shows that the new type gel plugging agent provides liquidity with the short gelling time, meeting the field needs; meanwhile it can also bear high load, and offer significant gel breaking performance, eliminating pipe sticking. The new type plugging agent was very effective in the Guangdong Heyuan area, and featured of easy concoction and without adding any special equipment. It will find promising application in areas with large size caverns and fractures.

Abstract:The construction of ZK1013 hole in Zhuxi mining area was introduced, the severe collapse happened at the sections of 470～491, 630～650 and 703～709m. According to the formation conditions and based on the analysis on the reasons of the wall instability, 2 sets of composite slurry system suitable for diamond wire-line coring process were proposed and good results were achieved.

Abstract:Based on the basic performance requirements of cement slurry in deep and ultra-deep wells in Tahe peripheral blocks and considering the effect of high temperature and high pressure on the cement slurry performance, by analyzing the mechanism of thermostable materials, the additives suitable for thermostable cement slurry are selected. The retarder, fluid loss additive, nano liquid silica and some other thermostable materials are mixed according to the requirements to carry out the research on thermostable（≥120℃）cement slurry system with different density and measure the regular properties. This series of cement slurry, with the characteristics of good fluidity, API filter loss less than 50mL, anti-gas-migration coefficient SPN less than 1, high temperature stability and high compressive strength of the set cement, can meet the technical requirements for high temperature and high pressure underground construction. This series of thermostable cement slurry have been used in the cementing of the well-SHBP1H， well-SHB7 and well-Zhongtan1 with high excellent rate.

Abstract:Countries worldwide are increasing the exploitation of high temperature geothermal resources, due to their wide distribution, cleanliness and environment-friendliness. During drilling of the high temperature geothermal well of Geo2E, a geothermal power generating project of the Turkish company ECOLOG, research has been conducted on some drilling techniques to tackle high temperature geothermal drilling difficulties from various aspects, such as well structure design, drilling rate improvement, high-temperature resistant drilling fluid, safety drilling technology; and field application of these techniques has achieved good results. The successful high temperature geothermal drilling experiences in this area can be drawn on to enhance the economical and effective utilization of high temperature geothermal resources in China.

Abstract:The poor cementing quality occurred in some high pressure salt-gypsum layer of Missan oilfield is analyzed together with the influence on the next operation are analyzed, the design of preflush and cement slurry, on-site inspection of casing and liner, borehole requirements before casing running, borehole requirements before cementing, casing eccentricity, cementing by mud grouting & displacing and cementing quality checking are successfully applied in the high pressure salt-gypsum sections of 47 well, which provides a reference for the cementing quality improvement in similar situation.

Abstract:Slag slipping wells are often used in the projects of mining and tunneling, which can be dredged through drilling with casing by using top head drilling machine and wire-line core drilling tools to deal with the frequent clogging accidents. Based on the example of the slag slipping well dredging construction in Xiaolangdi Dam Yellow River diversion project, this paper introduces the dredging methods, supporting equipments, operation rules and attentions, summarizes the experience and deficiency of the drilling with casing to provide practical reference for similar dredging projects.

Abstract:Ice cores contain vast amounts of paleoclimate and paleontological information. These are important for climate change and biological evolution from ancient times to modern times. How to acquire clean ice cores efficiently and quickly is an important issue for polar scientists.The continual air-reverse-circulation ice coring drill use a double-wall drill pipe to form a reverse circulation channel. The inner pipe provides a continuous channel for transporting the ice chips and cores from the bottom of the hole to the ice sheet surface.The drill can break the ice core by its breaker, and move the ice core continuously through the reverse circulation channel, so as to realize the continual coring. By using ABAQUS software, this paper analyzes the process of ice core breaking, use of XFEM fracture criterion and Explicit method, choose appropriate breaker size and center channel size, so as to get better effect of reverse circulation drilling.

Abstract:This paper introduces the working principle and structure characteristics of a pipe storage mechanism for drill rods and drilling tools used in deep seabed. According to the deep seabed drilling process, the automatic rod making up & breaking out and storage mechanism are designed. This kind of mechanism has 2 single-row rotary cage type pipe storage racks to store the drill pipe and drill pipe assembly respectively. Each pipe storage rack is equipped with a pair of manipulators to clamp the drill rod and drilling tools between the borehole mouth position and the outlet position of pipe storage rack for the transfer and tightening positioning. This mechanism has the advantages of high reliability, high coring rate, simple structure and convenient operation.

Abstract:JSN2B mud purifier is a kind of mud treatment equipment commonly used by geological prospecting units. Because the vibration is produced by eccentric block driven by motor belt transmission for the vibrating screen system, it is inconvenient to maintain the equipment and replace the sieve mesh in the practical application, which affects the normal use of the purifier. Through research and analysis, the vibration motor and composite sieve mesh were adopted to transform it. The actual use of one year proves the good effect, convenient maintenance and significantly improved benefit.

Abstract:With the tight control of the water level of the non-flood season (0.6m/d) in the Three Gorges Reservoir area, nearly 1000 landslides are prevented from a large-scale sliding into the river. However, the control of the reservoir drawdown rate in flood falling period limits the flood control and the benefits of hydroelectric power generation to a certain extent. In this paper, the feasibility of raising the reservoir drawdown rate in non-flood season is studied, Seep/W and SLOPE modules in Geo-studio are used to analyze the seepage and evaluate the stability of landslide on the ditch side. On this basis, the reservoir drawdown rate in flood falling period can be determined, which has significant practical significance and scientific value for the adjustment of drawdown rate in the Three Gorges Reservoir area.

Abstract:There are a large number of natural slopes and artificial slopes in the upgrading project of the Shitouping scenic area in Jincheng Park of Lanzhou. Due to the variability of the physico-mechanical parameters of slope soils, the Monte Carlo random sampling method and limit equilibrium method were used to calculate and analyze the slope stability reliability indexes and the change rules according to different slope heights and gradients. The results show that the slope is stable and reliable in the area of the actual slope height and slope gradient range, which is suitable for the scenic spots construction. However, when the slope height and slope gradient reach the maximum or over-range of the actual range, the slope is in a basically stable or under-stable state, the reinforcement measures are suggested.

Abstract:Strength reduction method is applied in the slope stability analysis, the soil strength is reduced and calculated by finite element program until the calculation convergence. At this time, the reduction coefficient is the safety coefficient. Combining with the engineering case, the slope stability is analyzed using the strength reduction method; meanwhile, also using Swedish arc method and with the geotechnical engineering design software Tianhan as well as the finite element analysis software ABAQUS to analyze slope stability and compared the safety coefficient. It is concluded that the safety coefficients obtained by these 3 calculation methods have little difference and the coefficient accuracy can meet the engineering requirements.

Abstract:Pumping test is carried out in the silty soil interlayer in the third hard soil layer in Shanghai, that is, 10th layer of confined aquifer. The water level, surface settlement and deep layer settlement are observed. 3-dimensional seepage and Biots consolidation theory simulation are used to analyze the relationship between the vertical deformation of the stratum and the change of the groundwater table during the deep confined water pumping process, which provide the basis for groundwater control in ultra deep foundation pit.

Abstract:Most of the engineering geological environments near the foundation pit of urban buildings are complex with narrow construction space. The general supporting methods, such as pile-anchor structure, can not be used because of the influence of the existed piles of the around buildings. It is more difficult for the construction when low shear strength of foundation pit slope soil layer and long embedded length of the supporting pile are encountered. Combined with a comprehensive design in Xingtai City, this paper presents a foundation pit support project with double-row piles + water-proof curtain between piles + foundation reinforcement. Double-row piles can increase the slope stiffness, water-proof curtain between piles can save the construction space and is helpful to solve construction space restriction, improve the shear strength of the foundation and shorten the length of supporting piles.

Abstract:In a foundation pit supporting engineering of Zhenzhou, the pile-anchor support, micro-pile + pre-stressed anchor composite soil nailing wall support and micro-pile composite soil nailing wall support systems are adopted respectively. The paper introduces the design and construction schemes of slope retaining pile, pre-stressed anchor cable, micro pile, pre-stressed anchor, soil nailing wall and perforated pipe pile in detail, as well as the emergency response plan adopted for the abnormity in foundation pit deformation monitoring, this technical achievement provides reference for the design and construction of similar projects.

Abstract:CFG pile composite foundation treatment technology is a widely used foundation treatment method. According to the site geological conditions of Yiquanguomao Hotel project and the actual situation of the project, the CFG pile is designed for the foundation treatment. The design and construction of CFG pile are introduced. The test results show that the application of CFG pile composite foundation treatment technology is a feasible basic scheme under the premise of ensuring construction quality in high-rise and even super high-rise buildings.