贵州煤层气合层开发的地质影响条件分析

Analysis on Geological Influence Condition of Coalbed Methane Development in Guizhou

通过对贵州5口生产井数据及其组合煤层的储层物性数据分析,发现随着组合煤层跨度、储层压力梯度差值、煤层层数的增大,煤层气井的日均产气量呈现逐渐减小的趋势。随着组合煤层的渗透率差值增大,煤层气井的日均产气量呈现逐渐增大的趋势,分析原因是渗透率差值大的组合煤层平均渗透率大,渗透率差值小的组合煤层平均渗透率小。建议贵州煤层气开发应优选组合煤层跨度小、储层压力梯度差值小、煤层层数少、渗透率大的储层。

By analyzing the data of 5 production wells in Guizhou and the reservoir physical property of the combined coal seam, it is found that with the combination of coal seam span, reservoir pressure gradient difference and coal seam number increasing, the daily average gas production of coalbed methane gas well decreases gradually. With the difference of permeability between the combined coal seams increasing, the daily average gas production of coalbed methane wells is increasing gradually, the reason is that the average permeability of the combined coal seam with large permeability difference is large, and the average permeability of the composite coal seam with small permeability difference is small. It is suggested that the coalbed methane development in Guizhou should preferably be a reservoir with small span, low reservoir pressure gradient difference, low seam layer and large permeability.