China University of Petroleum China United Coalbed Methane Corporation Limited

针对煤层气井有效排采时间短的问题,基于煤层气井稳定渗流方程和朗格缪尔吸附定律,建立了径向流煤层气井和压裂煤层气井排采面积影响单井产气潜能的数学模型,分析了排采面积对单井产气潜能的影响,并研究了煤层气井单井控制的有效解吸边界。结果表明:压裂煤层气井和径向流煤层气井解吸量与解吸半径之间的变化趋势大致相同,其解吸量随着解吸半径的增加接近于二次函数变化,解吸半径增加10倍,解吸量大约增加46倍。排采面积越大,煤层气井产气潜能越大。径向流煤层气井井底压力为1.0 MPa时,其单井控制解吸边界半径为99.73 m,其有效解吸边界的研究为煤层气开采合理布置井网提供了依据。

According to a short effective drainage time of coalbed methane well, based on the stable seepage equation of coalbed methane well and the Langmuir adsorption law, a mathematical model of drainage area of radial flow coalbed methane well and the fractured coalbed methane well affected to gas production potential of single well was established. The drainage area affected to gas production potential of single well was analyzed and the effective desorption boundary controlled by th e single coalbed methane well was studied. The results showed that the variation tendency between desorption volume and desorption radius of fractured coalbed meth ane well and radial flow coalbed methane well was almost the same. The desorption volume would be close to a quadratic function variation with desorption radius incre ased. The desorption radius was increased by 10 times and desorption volume was increased by about 46 times. The larger of the drainage area was, the higher gas pr oduction potential of coalbed methane well would be. When the bottom pressure of radial flow coalbed methane well was 1.0 MPa, the desorption boundary radius contr olled by the single well would be 99.73 m. The study on the effective desorption boundary would provide the basis to the rational layout well network of the coalbed met hane mining.

国家自然科学基金资助项目(51174224)；国家科技重大专项资助项目(2016ZX05066004-002)；中央高校基本科研业务费专项资金资助项目(16CX02004A)；