地学数值模拟技术.ppt

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1、地学数值模拟技术,韦重韬 教授 博士生导师资源与地球科学学院2009年,提纲,概述 数值模拟核心技术 煤层气成藏动力学过程模拟 油气盆地模拟技术 煤层气井排采过程模拟,资源与地球科学学院地学数值模拟技术课程提纲,煤层气成藏动力学过程模拟,地质模型,资源与地球科学学院地学数值模拟技术概述,In geological history,coalbed methane,The process,Factors control the process,A better understanding of this process would significantly improve evaluation

2、of CBM reservoirs for coalbed methane exploitation.,煤层气成藏动力学过程模拟,地质模型,资源与地球科学学院地学数值模拟技术概述,煤层气成藏动力学过程模拟,数学模型,资源与地球科学学院地学数值模拟技术概述,General description of the process by mass conservation,Qg quantity of gas generated by coal organic material,m3/t;Qs gas storing in coal reservoir,m3/t;Qd gas dissipated f

3、rom the coal reservoir,m3/t;,Gas Generation Qg by thermal simulation test of coal organic matter,Ro,max vitrinite reflectance of coal,%;Mn pure organic material in coal(dry,ash-free),t/t-coal;and Fg(Ro,max),In Qinshui Basin:,Maturation history of coal organic material is a key to access gas generati

4、on history,煤层气成藏动力学过程模拟,数学模型,资源与地球科学学院地学数值模拟技术概述,Dissipation of CBM Qd through different ways,Qdi diffusing from coal reservoir to cap,m3/t;Qob flow through cap via cap outburst,m3/t;Qpe permeating through coal reservoir to open passages or open atmosphere,m3/t.,Diffusion dissipation quantity Qdi co

5、ncentration diffusion,C free gas concentration in coal reservoir or cap,m3/m3-coal or m3/m3-cap;D diffusion coefficient,m2/s;t evolution time,sec.;Z points at the normal direction which is vertical to coal bed plane,m.,then:,S and V the diffusion area,m2,and volume of coal seam,m3;average bulk densi

6、ty of coal,t/m3;dC free gas concentration difference,m3/m3-coal;dH thickness of cap rock,m at the time diffusion occurs,sec.,煤层气成藏动力学过程模拟,数学模型,资源与地球科学学院地学数值模拟技术概述,Capoutburst dissipation quantity Qob simplified arithmetic,Permeation dissipation quantity Qpe similar to the above,Pop and Pcl reservoir

7、 pressures before and after cap outburst takes place,Pa;Pov overburden pressure,Pa;v Poissons ratio;Pt tectonic stress,Pa;t tensile strength of cap rock,Pa;Qpop and Qpcl gas contents under the reservoir pressures before and after cap outburst takes place,m3/t,Qcop and Qccl gas contents under the res

8、ervoir pressures before and after cleats open,m3/t,煤层气成藏动力学过程模拟,数学模型,资源与地球科学学院地学数值模拟技术概述,Preservation of CBM Qs Langmur Equations,Va adsorbed gas volume(in saturation state),m3/t;P reservoir pressure,Pa;a and b Langmuir volume(m3/t)and Langmuir pressure(Pa-1)constantsVf free gas volume per tone coal

9、,m3/t;T reservoir temperature,K;z the compressibility coefficient;m mass of the free gas,kg/t;R gas constant(R=8.3145),m3Pa/molK;M molecular mass of gas,kg/mol,Reservoir pressure becomes the key factor to control gas content,煤层气成藏动力学过程模拟,数学模型,资源与地球科学学院地学数值模拟技术概述,Preservation of CBM Qs Langmur Equati

10、ons,Pw and Pg the pressures caused by water potential energy and by gas generation,Pa;h relative elevation,m;average bulk density of coal,t/m3,density of water,kg/m3;g gravitational acceleration,m/s2;P0 and T0 reference pressure,Pa,and temperature,K;Vg the volume of pores per tone coal,m3/t;V0 volum

11、e of free gas per tone coal at standard conditions,m3/t;Tc coalbed temperature,K;Cp and compression coefficient and porosity of coal matrix,煤层气成藏动力学过程模拟,计算机软件,资源与地球科学学院地学数值模拟技术概述,Next time step,N,Y,煤层气成藏动力学过程模拟,计算机软件,资源与地球科学学院地学数值模拟技术概述,煤层气成藏动力学过程模拟,研究实例-沁水盆地位置,资源与地球科学学院地学数值模拟技术概述,Qinshui Basin,煤层气成

12、藏动力学过程模拟,研究实例-埋深图,资源与地球科学学院地学数值模拟技术概述,煤层气成藏动力学过程模拟,研究实例-地层,资源与地球科学学院地学数值模拟技术概述,煤层气成藏动力学过程模拟,研究实例-埋藏史,资源与地球科学学院地学数值模拟技术概述,煤层气成藏动力学过程模拟,研究实例-热史,资源与地球科学学院地学数值模拟技术概述,煤层气成藏动力学过程模拟,研究实例-成熟史,资源与地球科学学院地学数值模拟技术概述,煤层气成藏动力学过程模拟,研究实例-其他参数,资源与地球科学学院地学数值模拟技术概述,Other features:,CleatPorosity of coal matrixCoal seam

13、&coal qualityPhysical features of capSimulation grid post,煤层气成藏动力学过程模拟,研究实例-其他参数,资源与地球科学学院地学数值模拟技术概述,Other features:,CleatPorosity of coal matrixCoal seam&coal qualityPhysical features of capSimulation grid post,G17will be shown in next slide,煤层气成藏动力学过程模拟,研究实例-模拟结果,资源与地球科学学院地学数值模拟技术概述,Post G17,Evolu

14、tion curves,煤层气成藏动力学过程模拟,研究实例-模拟结果,资源与地球科学学院地学数值模拟技术概述,Evolution stage,煤层气成藏动力学过程模拟,研究实例-模拟结果,资源与地球科学学院地学数值模拟技术概述,煤层气成藏动力学过程模拟,研究实例-模拟结果,资源与地球科学学院地学数值模拟技术概述,煤层气成藏动力学过程模拟,研究实例-模拟结果,资源与地球科学学院地学数值模拟技术概述,煤层气成藏动力学过程模拟,研究实例-模拟结果,资源与地球科学学院地学数值模拟技术概述,煤层气成藏动力学过程模拟,研究实例-模拟研究的意义,资源与地球科学学院地学数值模拟技术概述,研究煤层气成藏的动力学过程 对深部区煤层气含量进行预测,