压力控制下高煤阶储层煤层气井排采的流体效应

摘要

为得到高煤阶储层煤层气井排采的压力-产气-产水动态平衡关系，揭示不同压力控制下的煤储层煤层气井排采的流体效应及机制，以沁南地区 X1和 X2煤层气井为研究对象，在 X1煤层气井排采阶段划分的基础上，分析了不同压力条件下的煤储层煤层气井排采解吸规律及流体效应；研究了不同排采阶段的套压、动液面高度、井底压力及枯竭压力与产能的关系；数值模拟了 X2煤层气井在压力控制前后的产能变化特征。结果表明：煤层气井排采的流体效应取决于是否对排采见气初期套压进行控制，排水阶段结束后采用蹩压、控压的排采制度，可有效提高煤层气井的产能。%In order to obtain the dynamic equilibrium relationship among pressure,gas and water production in coalbed methane well drain-age of high rank coal reservoir,and reveal coalbed methane drainage effect as well as its mechanism under pressure control,taking X1 well and X2 well in southern Qinshui basin as examples,and based on drainage stages classification of X1 well,fluid effect and desorption laws in the two coalbed methane wells drainage were analyzed under changing pressure,relationships among gas production and casing pressure, dynamic liquid level height,pressure of downhose,depletion pressure were discussed and researched,and the variation characteristics of gas production before and after pressure control of X2 well were numerically simulated.The results showed that fluid effect in coalbed methane wells depend on control of casing pressure in the initial stage of drainage,a shutoff pressure and controlling pressure production system could contribute to coalbed methane well productivity effectively.