煤层气井井底流压分析及计算

煤层气井井底流压的大小直接决定煤层气产量的大小，为了获得高产，必须清楚认识井底流压并精确计算其数值。根据垂直气液两相环空管流理论，首先描述了煤层气的环空流动特征及井底流压的组成部分；结合现场生产测试资料，采用Hasan-Kabir解析法和陈家琅实验回归两种方法计算了井底流压值，并分析了其与气体流量的关系。结论认为：①油套环空中流体由上而下分为纯气体段、混气液柱段（高含气泡沫段和普通液柱段），井底流压为套压、纯气柱压力及混气液柱压力三者之和；②两种方法计算的井底流压值大体相同，与实测值误差小，精度高；③井底流压与气体流量呈负相关关系，而且随着井底流压下降，压降漏斗不断扩大，井底流压下降相同的数值能产出更多的煤层气。

Analysis and computation of flowing bottom-hole pressure in coalbed methane wells

The production of coalbed methane wells are directly determined by the flowing bottom-hole pressure(FBHP).In order to gain high production,it is necessary to know the FBHP of coalbed methane wells and calculate its value exactly.According to the theory of vertical two-phase flow in annulus,this paper first described flowing characteristics in annulus and the parts of the FBHP in coalbed methane wells.Then,in combination with the production and testing data,the FBHP was calculated by two methods,i.e.,Hasan-K...