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通过对近年来鄂北工区所施工井的钻井资料进行分析、对比,优选出了适合于各区块、各井段的钻头型号和钻井参数,提高了机械钻速,缩短了钻井周期,使鄂北工区的钻井技术上了一个新的台阶,加速了鄂北气田的建设。 相似文献
106.
Three dimensional numerical simulation of residential building on shrink–swell soils in response to climatic conditions 下载免费PDF全文
Shrink–swell soils can cause distresses in buildings, and every year, the economic loss associated with this problem is huge. This paper presents a comprehensive system for simulating the soil–foundation–building system and its response to daily weather conditions. Weather data include rainfall, solar radiation, air temperature, relative humidity, and wind speed, all of which are readily available from a local weather station or the Internet. These data are used to determine simulation flux boundary conditions. Different methods are proposed to simulate different boundary conditions: bare soil, trees, and vegetation. A coupled hydro‐mechanical stress analysis is used to simulate the volume change of shrink–swell soils due to both mechanical stress and water content variations. Coupled hydro‐mechanical stress‐jointed elements are used to simulate the interaction between the soil and the slab, and general shell elements are used to simulate structural behavior. All the models are combined into one finite element program to predict the entire system's behavior. This paper first described the theory for the simulations. A site in Arlington, Texas, is then selected to demonstrate the application of the proposed system. Simulation results are shown, and a comparison between measured and predicted movements for four footings in Arlington, Texas, over a 2‐year period is presented. Finally, a three‐dimensional simulation is made for a virtual residential building on shrink–swell soils to identify the influence of various factors. Copyright © 2015 John Wiley & Sons, Ltd. 相似文献
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This paper presents a novel dynamical model to analyze the long‐term response of a percussive drilling system. This departs from existing approaches that usually consider a single activation and bit/rock interaction cycle for the analysis of the process performance. The proposed model integrates the axial dynamics of an elastic piston and an elastic drill bit, a motion‐dependent pressure law to drive the piston, and a generalized bit/rock interaction law representative of the dynamic indentation taking place at the bit/rock interface. It applies to down‐the‐hole percussive drilling as well as top‐hole, with minor modifications. The model does not account for the angular motion or the hole cleaning, however. The model is first formulated mathematically; then, a finite‐dimensional approximation is proposed for computations. Numerical analyses of the model response, for a low‐size down‐the‐hole percussive system, follow. The period‐1 stationary response for the reference configuration is studied in detail, and parametric analyses assessing the influence on the rate of penetration of the bit/rock interaction parameters, the feed force, and the percussive activation parameters are conducted. These analyses reveal that the multiscale nature of the process is well captured by the model and recover expected trends for the influence of the parameters. They also suggest that a significant increase of the penetration rate can be achieved by increasing the percussive frequency. Copyright © 2015 John Wiley & Sons, Ltd. 相似文献
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正20141864 Deng Mengchun(Institute of Exploration Technology,CAGS,Chengdu 611734,China);Huang Shenghui Rock Sample Collection and Division Technologies for Air Reverse Circulation Sampling Drilling(Exploration Engineering,ISSN1672-7428,CN11-5063/TD,40(7),2013,p.73-76,80,16 illus.,5 refs.) 相似文献
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The dynamic response of a mechanically stabilized earth wall to the passing of a high‐speed train is modelled using the finite element method. A three‐dimensional analysis is carried out, using a specific framework that allows performing the analysis with a moderate computational effort. In the first place, a so‐called multiphase approach is used to take into account the reinforcing strips. The moving load is taken into account by performing the calculation in a mobile referential using the properties of symmetry of the train cars and a simplifying assumption of periodicity for the whole train. We also assume a steady state. A partial validation of the approach is obtained by means of a comparison with an analytical solution. The quick increase in displacements induced by the train passing when the speed comes close to the celerity of Rayleigh waves clearly appears in the results. The vertical displacements, vertical stresses in the backfill, tensile forces in the strips and the influence of the stiffness of the soil are discussed. Copyright © 2017 John Wiley & Sons, Ltd. 相似文献
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CCSD-SK2井是一口钻穿松辽盆地白垩纪陆相沉积地层的中国大陆科学钻探井。二开段先以216mm口径钻至2806.20m,然后进行444.5mm口径扩孔。泥页岩地层大井眼钻进过程中粘土矿物含量高且易造浆,砂砾岩层渗透性强易粘卡,井壁稳定控制与钻屑携带难度大。选用了钾铵聚合物钻井液体系和聚磺钻井液体系,通过正交实验确定了钻井液配方。将钻井液控制在合适的密度、较低的失水量以及较强的封堵性,有效实现了井壁稳定;保持适当的环空返速、较高的动塑比以及定期打稠塞举砂等措施,有效实现了井眼净化。1086.45m~1147.56m与1182.74m~1256.01m井段累计收获岩心130.90m,取心率达到97.41%,平均机械钻速为0.84m/h;最终顺利钻至2806.20m。 相似文献