沁中南断层不发育区多期构造运动作用下煤层气直井产水产气特征

查明小范围内煤层气直井产气特征是减少工程盲目投资、准确进行产能预测的重要保障。通过对沁水盆地中南部小范围内断层不发育区不同构造部位煤层气井产气量、产水量差异主控因素的分析，得出小范围内燕山期、喜山期等多期构造运动作用引起的气水分异、渗透率差异是引起产气量和产水量大小的根本。底板标高差值引起气/水分异，最终导致小范围内储层压力梯度、产水量差异。煤层变形中等/较强区域多期褶皱叠加的隆起或凹陷块段，渗透率最低；变形弱/较弱区多期褶皱叠加的底板高值块段渗透率最好。小范围内储层压力梯度、水/气分流和渗透率的差异导致煤层气井表现出“水大气大、水大气小、水小气大、水小气小”等产气产水曲线特征。

Study on gas production and water production characteristics of CBM vertical wells under multi period tectonic movement of un-development fault in central south Qinshui Basin

It is important to reduce the blinding investment on the project and accurately predict the gas production by identifying the gas production characteristics of CBM vertical wells within a small range un development fault.Through the analysis of the gas production and water production of CBM vertical wells and the main controlling factors at different tectonic positions in the central and southern Qinshui Basin within a small range,the differences of gas transport and water transport and permeability in coupled stress superposition effects in Yanshan period and Xishan period are found as the essential reason for gas production and water production.The differences of floor elevation resulted in the differences of gas and water transport routes,reservoir pressure gradient and water production.The permeability is the lowest in the uplift or depression blocks of multi periods fold coupling areas in medium or strong deformation regions.The permeability is the highest in the high values of the floor elevation in weak deformation regions.The differences of reservoir pressure gradient,permeability and gas and water transport route within a small range lead to the differences of gas and water production curves characteristics.These characteristics are as follows:water and gas production are both high,water is high and gas is low,water is low and gas is high,water is low and gas is low.