Abstract:As the important means of “drilling down into deep earth”, scientific deep drilling and ultra-deep drilling become important methods, which are known as “telescope into the earth’s crust”. Ultra-high temperature and high pressure in scientific ultra-deep well is one of the most prominent technical difficulties in drilling operation, so rigorous standards were put forward to the drilling fluid, down-hole motor, aluminum alloy drill pipe and so on, the project becomes more difficult with higher risk and prolonged construction duration. This paper summarizes the characteristics of scientific ultra-deep drilling engineering and analyzes the effect of drilling fluid continuous circulation on borehole stability and downhole temperature, it is concluded that scientific ultra-deep well has strong technical demand for continuous circulation system and this system would provide technical support for future scientific ultra-deep drilling program in China.

Abstract:There are many factors which affect the displacement efficiency in the cementing process at horizontal wells. In these factors, the eccentricity of casing, rheological property of flushing fluid and density difference between flushing fluid and drilling fluid are prominent. In order to understand the influence of various factors on horizontal cementing, three-dimensional model of eccentric horizontal well was established by CFD software and numerical simulation study was made on drilling fluid being displaced by flushing fluid by means of VOF method. The inner and outer diameters of the simulated wellbore and casing are 177.8mm（7in）and 215.9mm（81/2in）respectively, the length of annulus is 300m, the displacement velocity is 1m/s and the casing eccentricity is selected 0，0.2，0.3 and 0.4 separately according to the specific example. The simulated results indicate that the eccentricity of casing at horizontal wells is unfavorable to cementing displacement efficiency, and increasing flow behavior index and decreasing consistency index are helpful for improving the stability of displacement interface, reducing its length and enhancing displacement efficiency as well. Meanwhile, when the positive density difference between flushing fluid and drilling fluid is formed, it is conducive to the improvement of displacement efficiency.

Abstract:Carbonate formations are widely distributed in Guizhou Province with karst caves, karst cracks and joint cracks developing. Karst caves are frequently encountered in deep geothermal well drilling operation. For the purpose of reservoir protection, it is usual to drill against loss circulation. In geothermal reservoir of ZK2 geothermal well of Guizhou, by drilling against loss circulation with low permeability film forming drilling fluid, the cost was reduced and the cuttings were discharged in time. This safe drilling case provides its experience for the application of low permeability film forming drilling fluid in deep geothermal well drilling.

Abstract:In order to improve the drilling speed of the horizontal well to reduce drilling investment in Qingshen gas field, a rotary percussion drilling test was carried out in the 3rd opening interval of Xushen1-Ping3. By the analysis on the strength of the BHA and according to the characteristics of hydraulic rotary tools with different dimensions, the acceleration technology scheme was formulated, the drilling parameters were optimized and the field tests were made. It was proved that there was obvious improvement in deep vertical section by hydraulic drilling. First of all, from the analysis on testing whether the new BHA strength meets the drilling requirements to prevent fatigue failure of drill caused by stress concentration. The drilling parameters were optimized by the pump pressure-displacement back-stepping formula of hydraulic rotary tools under the condition of the fact that the pump pressure of ZJ50D rig is generally no more than 25MPa in Daqing. Based on the parameter optimization result, the specific construction measures were formulated to ensure the successful field test of φ279mm hydraulic rotary tool.

Abstract:NaCl was selected as antifreeze to solve difficulties for drilling and coring in plateau permafrost and exploration process of gas hydrate, and salt tolerant copolymer GTQ and hydrolyzed polyacrylamide PHP were taken as main polymer reagent. With orthogonal test method, 9 groups of optimal formulas were obtained in normal temperature, after low temperature test, the drilling fluid formulation Z1（20%NaCl 0.1%PHP 1.2%GTQ 1%KHm）and Z2 （25%NaCl 0.15%PHP 1.0%GTQ 1%KHm）were determined, which could be used in the temperature of -15℃. The main performance indicators were: AV values were 46.5 and 47.5 MPa·s, PV values were 34 and 35MPa·s, YP values were both 12.8Pa and FLAPI were 6.8 and 7.6mL/30min. By the cost accounting, the 2 formulas are economic and can meet the requirements of plateau permafrost drilling.

Abstract:As a CBM production well, 2013ZX-SH-UM15V is located in Qinshui basin in Shanxi Province. Coal-bed coring was conducted in 3# and 15# coal-beds during the construction in order to obtain the coal-bed gas content and coal rock characteristics and some other parameters. Because of the soft coal in lower parts of 3# and 15# coal-beds, the core recovery was once very low, but combined with the coal rock characteristics in 3# and 15# coal-beds and by the repeated tests, core recovery was up to more than 90%. The paper summarizes the key technology of wire-line coring in soft coal-bed in this region.

Abstract:Aiming at the casing integrity after long period of production, as for the traditional remedial measures, such as with straddle packer, cannot meet the post-operation requirements for borehole size, external casing patch technology was proposed. The paper introduces the principles of the external casing patch and the application in HZ19-3-6 and HZ26-1-16 of Huizhou oilfield. The results show that the repaired casing can maintain the original strength and produce permanent seal with the advantages of remaining borehole size. The analysis is made on the complicated situations in operation process, which has practical and theoretical guiding significance for the repair work of marine oil casing integrity and provide reference and inspiration to casing repair of water well and geothermal well.

Abstract:Along with the daily progress of the society and everlasting development of economy, the application of pipe-jacking crossing technology is applied more and more extensively in oil and gas pipeline crossing engineering. However, the different pipe-jacking crossing modes should be selected according to different formation situations in practical application. This paper introduces the principle, characteristics and classification of atmospheric pressure balance pipe-jacking, and summarizes this construction technology in oil and gas pipeline crossing engineering in soft soil section with the engineering example of Zhongshan-Guangzhou natural gas pipeline.

Abstract:For the convenience of XY-44AT core drill in large inclined angle and vertical drilling, based on the investigation on China-made series derricks, a drill rig erected by double derricking cylinder and cable stayed with translation structure of crane pulley and hydraulic aided hoister was designed. Connected with the derrick bottom and with the crane and steel cable stayed frame on its top, the rig can be simply operated, by which the service performance is further broadened to improve the production efficiency.

Abstract:Based on the water drilling practice of geotechnical engineering investigation in the second phase of Beijing subway Line 6 project, this article introduces the oil drum raft drilling platform on the waters about its structure, features and scope of application. The design principle, design method and establishing plan are discussed and the safety measures of water drilling are summarized.

Abstract:Ball latch wire-line coring hydro-hammer was developed to solve the inner tube assembly fluctuation of existing SYZX series wire-line coring hydro-hammers, by which, the output impact work is increased with further drilling efficiency improvement. The indoor and production tests confirm that the principle of ball latch wire-line coring hydro-hammer drilling tool is feasible. The fishing and positioning reliability of this hammer are more than 95%, but some partial details still need to be improved in future productive practice.

Abstract:Because of the favorable mechanics performance between pile and soil, the application of DX pile achieves good results in construction project. By the analysis on DX pile about its mechanics characteristics between pile and soil as well as the geological conditions in Zhengzhou area, theoretical analysis and finite element numerical simulation were used to analyze the applicability of DX pile to provide the reference for engineering application of DX pile in Zhengzhou area.

Abstract:Based on an excavation retaining project in Beijing, the paper describes the application of pile-anchor retaining structure in excavation retaining and the deformation control from the design point of view. According to the stress features and structure characteristics, main reinforcement of slope protection pile is unevenly arranged and segment reinforcement is adopted. Concrete middle beam was added in the middle of brick wall to ensure the excavation safety. In the slope protection pile construction, different construction technologies were used to protect the old trees in the slope protection range. From the excavation point view, horizontal displacement on top of retaining structure and subsidence of surrounding building structures were monitored, and the anchor was tested and monitored. The analysis shows that the horizontal and vertical deformation of excavation are in the scope of designed control range, the foundation pit is of overall stability, the pile-anchor retaining structure has played an effective control effect on the deformation.

Abstract:Cantilever retaining structure is a commonly-used retaining form in excavation engineering, which comes in forms of row piles, diaphragm wall, SMW pile and steel sheet pile. The internal bracing is impossible under the confined conditions of excavation engineering, but parts of the peripheral buildings (structures) are sensitive to the excavation deformation. In this case, some auxiliary measures should be taken for excavation deformation. The paper introduces several commonly-used methods of deformation control in cantilever retaining structure with engineering examples, including two-row piles bracing, reinforcement by bolt (cable), inclined brace in foundation pit, soil consolidation in foundation pit and soil reserving for piles stability. Analysis is made on these methods about the application scope and technical requirements to provide the reference for the design and construction of similar engineering.

Abstract:Petrochemical device is high, large and heavy, for which, the bearing capacity of foundation and the settlement deformation should be strictly controlled. The paper presents a petrochemical project in soft soil of Ningbo, because of the poor engineering geological conditions and large wind load, the horizontal bearing capacity is a very important factor. In order to achieve the horizontal bearing capacity parameters of pile foundation in accordance with the practical conditions, the horizontal static load test on the foundation of prefabricated square-pile is carried out under the conditions of different pile diameters, pile lengths and vertical loads on pile top in working area. The test results show that when the pile top is under the free condition, the horizontal bearing capacity of single pile increases along with the increase of diameter and the length of the pile, not being linear growth, but the power function relation. The horizontal bearing capacity of single pile increases along with the increase of vertical load on pile top, and also with power function relation. The horizontal bearing capacity of pile group is larger than the sum of that of single piles.

Abstract:According to the situation of pile hole diameter reducing and borehole detection data, and based on the engineering investigation report parameters, the causes of hole diameter reducing in thick dredger fill formation in coastal region and the corresponding relation between time and volume are analyzed. The solving methods were put forward, one is by adding bentonite or additive to increase mud weight and adjust other technical indexes in order to improve the performance of wall consolidation; another is by diameter expanding. And accurate control of the expanding amount is particularly important. With the hole formation test and construction data, the corresponding relation between diameter reducing amount and time is analyzed to find out the diameter reducing rules in order to obtain correct diameter expanding amount to provide the reference for the construction.

Abstract:The analysis was made on the uneven settlement causes of a workshop foundation, it was considered the insufficient bearing capacity of foundation, the consolidation of foundation soil and the influence of ground water are main reasons. The foundation reinforcement should be made by mainly grouting with combination of permeability and compaction fracture grouting. By the indoor experiments and engineering grouting tests on the grouting materials of SJP and pure cement slurries, it is proved that SJP slurries have the features of good initial fluidity, strong groutability and controllable initial and final setting time etc., which is superior to the traditional pure cements for the application in the foundation reinforcement of large porosity and heterogeneity. 72 holes were grouted with SJP in the reinforcement project, 173m3 grouting materials and 173t cements were used, with about 108t cement being saved.

Abstract:On the right bank of Wudu reservoir of Sichuan, silt and fine sand layer with thickness of 2.3～9.8m exposed in EL574m grouting adit; in this case, reliable anti-seepage curtain can not be formed by high pressure grouting with ordinary cement. By the use of a combined grouting method of high pressure jetting grouting, wet grinding fine cement and chemical grouting, good construction effect is achieved. The construction was tested by water pressure in borehole, high-power acoustic CT, single-hole acoustic wave and drilling digital panoramic imaging, which indicates that the construction has met the requirement of designed seepage control.

Abstract:According to the poor effects and low efficiency of tunneling blasting at the initial production of an iron mine of Hebei, the optimization was mainly carried on blasting parameters in blast-hole interval and arrangement. The production practice proves that tunneling effect has been improved with lowered blasting cost by the optimized blasting parameters, which have been applied in actual production.