考虑吸附、变形的煤层气分阶段流动模型  

A stage-by-stage flow model of coalbed methane gas considering adsorption and deformation

作　　者：欧成华[1] 梁成钢[2] 蒋建立 张俊成[1] 

机构地区：[1]"油气藏地质及开发工程"国家重点实验室.西南石油大学 [2]中国石油新疆油田公司准东采油厂 [3]新疆准东石油技术股份有限公司

出　　处：《天然气工业》2011年第3期48-51,110-111,共4页Natural Gas Industry

摘　　要：煤岩具有微孔—中孔—大孔—裂隙多重孔隙结构,中孔—大孔中的煤层气流动规律是连接微孔解吸和裂隙渗流的桥梁,是揭示煤层气解吸—扩散—渗流分阶段产出机理的关键环节。基于受煤岩变形影响的煤层气分阶段产出特征和规律分析,建立煤层气在基质微孔表面解吸、由基质微孔向基质较大孔扩散、在基质较大孔中和裂隙空间中渗流的分阶段流动数学模型,求取裂隙中气—水两相隐式压力显式饱和度有限差分线性方程组,计算出晋试1井煤层气的产出动态,验证了考虑吸附变形的煤层气分阶段流动模型的可靠性,为完善煤层气产出动态分析和预测方法提供了理论依据。A coal rock's multi-pore structure is made up of micro,mediate,large pores and fractures.A coalbed methane(CBM) flow pattern between mediate and large pores sets up a bridge between micro-porous adsorption and seepage flow of fracture,which is the key point to illuminate the mechanism of development for multiple stages such as desorption-diffusion-seepage process.Based on an analysis of the stage-by-stage output characteristic of CBM which is influenced by coal rock deformation,a mathematical model is constructed from the desorption stage at the surface of micro-pore,to the diffusion stage from micro-pore to meso-pore or macro-pore,then to the percolation stage between macro-pore and fracture.By use of this model,the finite-difference linear equations of gas-water two-phase implicit pressure explicit saturation are obtained by using the IMPES method;the dynamic performance on the CBM well Jingshi-1 is thus calculated,the results of which have shown the reliability of this stage-by-stage flow model of CBM with the consideration of desorption and deformation.This provides theoretical foundation for the improvement of the CBM's dynamic analysis and prediction methods.

关 键 词：煤层气 流动 阶段 吸附 变形 数学模型 泌水盆地 

分 类 号：P618.11[天文地球—矿床学]