Abstract:Achievement and development were reviewed in scientific drilling, gas hydrate exploration, deep drilling; drilling technical equipment; high precision directional butted well drilling; wire-line coring hydro-hammer; new diamond bit series; new flushing fluid; drilling technology for monitoring and control of geological disaster; talent training and the system reformation in Eleventh Five-year Plan period in China; and main work direction in the Twelfth Five-year Plan period was put forward.

Abstract:A comprehensive review is made of advances in drilling technology and equipment (including core drilling, engineering drilling and water well drilling) during the Eleventh Five-year Plan period in China, with their development trend, characteristics and direction envisioned for the Twelfth Five-year Plan period in terms of technology, product and market.

Abstract:The achievements and progresses made in geo-drilling by China Nuclear Geology during the Eleventh Five-year Plan Period are reviewed and summarized in terms of drilling operations, drilling R & D, drilling project management, drilling capacity building, and drilling force construction. A concept of ‘enhance talent cultivation, improve technological innovation, intensify capacity building, and implement fine management’ is proposed for the Twelfth Plan Period.

Abstract:Both the temperature and pressure are key parameters to keep natural gas hydrate as solid. Based on thermal physical mechanics and the characteristic property of ideal gas, and by computer simulating the decomposition of methane hydrates and carbon dioxide hydrates under different temperature(all above 0℃) and pressure conditions, the P-T balance station of methane hydrate dissociation was obtained and the relationship between temperature and pressure for land gas hydrate sampling was discussed.

Abstract:Determining the borehole trajectory is the premise of analyzing and correcting drilling deviations. Taking the borehole depth s measured during inclination survey as the variable, this paper establishes a parameter equation for the borehole trajectory with polynomial fitting, and a new mathematical model for the 3D borehole trajectory is therefore deduced. Calculations demonstrate that the new model gives better accuracy.

Abstract:Water-gushing in sandstone and sand-shale collapsing were effectively solved by managed pressure drilling technology in Yaozhuang coalfield, which played important role in improving drilling efficiency and reducing construction risk. The practice provided the construction experience for drilling in this area.

Abstract:Many problems were encountered in the drilling procedure of H020U of Beypazari trona mine in Turkey, such as the drilling fluid leakage; the severe bit abrasion by the hard silicified limestone; hitting the production casing of V020; brine gushing; instrument dropping into the open hole; inclination angle going down and azimuth deviating with the unexpected cavity, which caused the second target was not hit, and so on. All of these problems were analyzed and the corresponding solutions were brought forward. Finally both of the first target V020 and the second target V020U were successfully connected by H020U.

Abstract:Measurement while drilling is one of the key technologies of directional drilling in coalmine, the article introduced its characteristics and the working principles, simply illustrated the design and flowchart of directional drilling technology and described the applications of gas drainage in several coalmines.

Abstract:Sonic drilling coring is a relatively new exploration technique for drilling and sampling application in the fields of soil environmental and geo-technical exploration. It uses high frequency vibrations (50~200 Hz) generated by 2 symmetrical rollers in the sonic head (oscillator) to vibrate drill pipe or outer casing for drilling. The rollers’ vibration is synchronized to ensure that the vibration is transmitted vertically down the drill string to the bit. The paper introduced TGSD-50 sonic drilling coring rig about the structure design, main technical parameters and the features.

Abstract:Based on the analysis on LS-DYNA dynamic finite element, rotating fitting expansion tubular model was established with the whole expansion process simulation. By the analysis on stimulation results of different constraint methods to the tubular, it was found that the swelling force required in rotating fitting expansion is 1/5 of that in reverse tensile of solid cone; and change rule of axial length of the expansion tubular was variable in deferent constraint methods: with upper constraint method, the tubular length was a little decreased at first, and then steadily increased; while with underneath constraint method, the tubular length decreased all the time. This rule was proved by the rotary expansion test on Φ95mm tubular, the simulation was credible.

Abstract:Thread-sticky is a popular failure mode of drilling tool, and rotary-shouldered thread takes a great proportion in drilling string thread. By the analysis on the cause of thread-sticky in rotary-shouldered threads, it is put forward that the manufacture material, processing and operation factor have direct influence. The paper suggested the main measures for thread-sticky prevention.

Abstract:The in-situ testing instrument for ground thermophysical properties can be used to measure accurately the ground thermophysical parameters. This paper describes the in-situ testing instrument in terms of its principle, structure and components, characteristics， testing method and data processing. With the Ingersoll simplified model， it is found that a total of 498 geothermal wells with depth of 100m are needed to meet the heating requirement in Shuangliao Service Station.

Abstract:To prevent the bridgehead segment structure cracking, displacement, shear failure and the pile settlement after construction, DJM and geogrid joint reinforcement is used in soft ground reinforcement. It can bind the lateral deformation of the foundation; reduce the differential settlement of embankment and roadbed extrusion, effectively reduce the total settlement amount of the surface with good effect for preventing vehicle bouncing at bridge approach.

Abstract:This paper introduces the design and construction of a deep excavation support engineering in Nanjing and mainly elaborates the successful application of bored cast-in-place pile and deep-mixing pile in engineering case. This is a new experience in deep excavation support construction.

Abstract:With the advantages of simple construction, fast pile completion and low engineering cost, vibroflotation method is widely applied in the ground treatment, such as sand soil, silt soil, clay, artificial filled soil and sludge ground. Based on the ground vibroflotation reinforcement project of Beihai power plant, the paper analyzed the application of vibro-replacement pile in sludge soil and the treatment effect.

Abstract:The paper introduced an incline-prevention drilling tool for bored grouting pile construction with high verticality requirement, and introduced this gravity guide incline-prevention drilling tool about its design, processing and the application effect in bridge foundation engineering of Changjiang highway bridge in Jiujiang. Theoretical analysis was made on the principle of incline-prevention.

Abstract:By the construction practice of a tower foundation pile in Tianjin, the verticality control for super-long thin pile was tested and studied, some measures were put forward and construction experience was summed up.

Abstract:Pump displacement and drilling speed are 2 pivotal parameters in HDD. The matching state of pump displacement and drilling speed will affect the borehole quality and the construction progress, but there is no mature academic system to obtain them, for little research has been done in China, these parameters usually are estimated with experience in construction. In this article, mathematical analysis method is used with the consideration on the influence of drilled cuttings amount, calculating model of optimization of pump displacement and drilling speed is established combining with testing data for verification. It is proved by practice that this model is according with field construction.

Abstract:This paper discusses the varieties and causes of winch sliding-down accident in geological exploration and mine inclined shaft, introduces current situation of study on safety device for sliding-down prevention in inclined shaft both in China and abroad. Based on the comparison of anti-sliding-down devices, the prospect of the anti-sliding-down safety device for small cross-section exploration inclined shaft is forecasted.

Abstract:Stress-strain of surrounding rock is an important foundation for analyzing the stability of tunnel excavation. The mature tunnel mechanics is mainly to numerically simulate the tunnel excavation at the present. In this paper, with large finite element software ANSYS, stress-strain of surrounding rock of the saddle-shaped shallow tunnel excavation in soft rock of different depth, slope angle and covering layer thickness are calculated and analyzed, the laws are educed, the schemes is compared and the reasonable scheme is confirmed. The results show that: it is reasonable for 2 times of the tunnel depth as the judgment of deep or shallow unsymmetrical tunnel; it is reasonable to reduce the depth and covering layer thickness on the condition that surrounding rock is stable without wall spalling and roof caving. The laws of stress-strain of the surrounding rock internal wall in the tunnel excavation may provide reference to selection of the supporting structure parameter.