煤层气排采曲线特征及其影响因素分析

CBM Emission and Exploitation Curve Features and Analysis of Influence Factors

本文对胡底工区124口煤层气井排采曲线进行了分析,研究结果表明:在各阶段产气量与套管压力均呈正相关关系。在迅速加大抽水力度后的第二阶段煤层气井产气量增加明显,但衰减较快,单峰型煤层气井产气量主要取决于稳定后第三阶段的产气量;"双峰型"煤层气井主要分布于产水量较大区域,产气量与产水量呈正相关关系,产气量的大小主要取决于产水量;"平稳上升性"煤层气井产气量随时间的增加而增加,但整体产气量较小,应在排采初期加大排水力度。

The study has analyzed the CBM emission and exploitation curves of 124 CBM wells in Hudi working area. The study shows that all the gas production rates in different phases have the positive corre- lation relationship with the casing pressure. The gas production rate of CBM wells in the second phase af- ter intensifying the pumping strength quickly rises apparently but declines quickly, and the gas production rate of unimodal type CBM wells mainly depends on that in the third phase after stabilization; the ＂bi- modal type＂ CBM wells are mainly distributed in the area with a large water production rate, the gas and water production rates have a positive correlation relationship, and the former mainly depends on the lat- ter; the gas production rate of ＂steady rising type＂ CBM wells rises with the increase of time but the whole gas production rate is small, so the strength of water draining should be intensified in the initial stage of CBM emission and exploitation.