【作者】 张瑜；

【导师】 谢晓佳； 易俊；

【作者基本信息】 重庆大学 ， 采矿工程， 2009， 硕士

【摘要】 我国高阶煤煤炭资源量巨大,煤层气资源量也很丰富,达3.58万亿立方米多。由于我国地质条件和含煤盆地的构造活动复杂,存在着独特的煤层气产气机理和产气规律,而国内外也没有形成系统地分析高阶煤产气机理和产气规律的理论。本文结合沁水盆地南部高阶煤的现场数据,以沁水盆地3#煤层为研究对象,通过研究该煤体的孔隙系统和孔隙微观结构、煤层气吸附解吸规律、渗流机理,提出沁水盆地高阶煤产气机理和规律;建立反映煤层气流动过程中吸附-解吸-扩散-渗流的气水两相渗流场、煤层应力-应变场的流固动态耦合模型,分析沁水盆地高阶煤的产气规律,对中国高阶煤煤层气的勘探开发具有实际的指导意义。本文主要开展的工作:①分析了国内外煤层微孔结构、煤层气吸附、扩散、渗流及流-固耦合模型等方面的研究现状,明确了本论文研究的意义、研究内容和研究方法。②在明确了高阶煤的界定的基础上,概述了我国高阶煤的资源分布特点以及我国主要高阶煤地区的煤层气生产与赋存,并提出了高阶煤煤层气的成藏特征;同时,分析了沁水盆地南部的基本地质概况。③实验研究了不同煤阶煤的孔隙特征和比表面积,高阶煤煤层气的吸附、解吸特性,在此基础上分析了高阶煤煤层气的吸附解吸机理。④分析了煤储层中煤层气渗流的基本特征,并通过实验研究了不同煤阶煤的渗透特性,实验得出煤的渗透性与煤级、应力场、温度场等有关;提出了反映煤层气在煤层裂缝隔理宏观孔隙系统中煤层气流动的渗流压力场、温度场和应力场的高阶煤煤层气单相流固耦合数学模型,并实现了以煤层瓦斯开采为初始和边界条件的数值解,有效模拟了高阶煤煤层气的渗流过程,分析了高阶煤煤层气单相气体排采规律。⑤实验研究了高阶煤煤层气、水两相渗流特性,提出了煤层气、水相对渗透率随饱和度变化时的规律和特点;建立考虑煤层气渗流压力场与煤体变形场的气水两相流固耦合的煤层气渗流模型,采用数值模拟手段分析考虑煤层气渗流压力场、煤体变形场和气水两相耦合作用时煤层气生产井周围的压力变化规律,分析高阶煤层气、水两相的排采规律。更多还原

【Abstract】 High rank coal resources in our country is hugely, and coalbed methane resources are also very rich, more then 3.58 trillion cubic meters. Because the geological conditions and the tectonic activity of coal-bearing basin are complexity in our country, there is a unique gas production mechanism and discipline of coalbed methane, while there is no theorem of gas production mechanism and discipline of coalbed methane formed by systematic analysis at home and abroad. This paper based on the field data of high rank coal in southern of Qinshui Basin , with the 3# coalbed in Qinshui Basin as the study object, researched the pore system and micropore structure , methane adsorption and desorption law, percolation mechanism of this coal, presented the gas production mechanism and discipline of high rank coalbed in Qinshui Basin; Set up a fluid-dynamic coupling model to reflect adsorption - desorption– diffusion - percolation on the flow behavior of coal-bed methane under gas - water phases seepage field and coalbed stress - strain field.Analysis of gas production law of high rank coal in Qinshui Basin. It has actual guidance meaning of exploration and development to the high rank coalbed methane in China.The main conclusions in this paper are as follows:①Analyzed the study status quo of coalbed microporous structure and methane adsorption– diffusion - percolation and fluid-dynamic coupling model at home and abroad , made sure the meaning and the measure and the content of research in this paper.②On the basis of definite the defined of high rank coalbed, overviewed the resources pattern of high rank coalbed, as well as the methane production and occurrence in major areas of high rank coalbed in China, and proposed a accumulation characteristics of high rank coalbed methane; At the same time, analyzed the fundamental geology in southern of Qinshui basin③Experimental studied the coal porosity characteristics and specific surface area of different coal ranks, the adsorption and desorption characteristics of high rank coalbed methane, analyzed the adsorption and desorption mechanism of high rank coalbed methane on this basis.④Analyzed the basic characteristics of methane seepage in coal reservoirs, and through experimental studied the coal permeability of different coal ranks, experiments obtained that the coal permeability is relatived with coal rank, stress field, temperature field, etc.. A fluid-dynamic coupling mathematical model including pressure, temperature and stress fields was deduced with single methane of high rank coalbed in connected cleats and fractures in coal matrix . And realized the numerical solution with the coalbed gas exploitation as initial and boundary conditions , a flow event of high rank coalbed methane was simulated effectively, and analyzed the single-phase gas production laws of high rank coalbed methane.⑤Experimental studied the seepage characteristics of two phases between high rank coalbed methane and water, developed the rules and characteristics that the relative permeability of methane and water changed with saturation; Set up a coalbed methane seepage model of gas and water phases Fluid-solid coupling that considered with coalbed methane seepage pressure field and coal deformation field, adopted numerical simulation means to analysis the pressure laws around the coal gas producing wells under considering seepage pressure field, coal deformation field and gas-water phases coupling, analyzed the methane– water phases production laws of high rank coalbed methane.更多还原