寿阳南燕竹区煤层气井排水降压阶段压降漏斗状态分析及其排采管控意义

Condition Analysis of Pressure Drop Funnel during Water Drainage and Depressurization Stage of CBM Wells and Significance of Drainage Management in South Yanzhu Area of Shouyang

通过定量计算南燕竹区4口不同产气量的典型煤层气井排水降压阶段的压降漏斗范围,发现在见气前压降漏斗扩展的越大,单井产气量就越高。但压降漏斗的扩展过程受储层压力、渗透率和排采制度影响,不同井的储层参数差异较大,即使是采用相同的排采制度,其漏斗扩展的过程也会有较大的差异。根据排水降压阶段漏斗范围与流压降速的对比,本区排水降压阶段最有利于漏斗扩展的流压降速在3kPa/d左右。

By quantitatively calculating the range of pressure drop funnel of four typical CBM wells with different gas production during the drainage and depressurization stage in South Yanzhu Area,it is found that the larger the pressure drop funnel expands before gas producing,the higher the gas production of single well.However,the expanding process of pressure drop funnel is affected by reservoir pressure,permeability and drainage system,and the reservoir parameters of different wells vary greatly,even if the same drainage system is adopted,the expanding process of funnel will also vary greatly.Based on the comparison between the funnel range and the velocity of flow pressure drop,the velocity of flow pressure drop which is most advantageous to the funnel expansion is about 3kPa/d.