基于灰色关联分析页岩气开采中水锁效应影响因素

Grey Correlation Analysis on Effect Factor for Water Blocking Exploited from Shale Gas

采用水力压裂法开采页岩气中,产生的水锁效应对页岩气的产能有很大的影响。为了探究各个影响因素对水锁效应的影响程度,分析了渗透率、孔隙度、束缚水饱和度、作业压差、气液界面张力5个影响因素与水锁效应的相关性。采用灰色关联分析法研究,结果表明:以渗透率伤害率表示水锁伤害程度,R01>R03>R02>R05>R04。即与渗透率的关联性最高,接着是束缚水饱和度,然后是孔隙度,再是作业压差,最后是气液界面张力。处理水锁效应,依次从关联度的高低进行处理,对页岩气的抽采有一定的意义。

During exploit shale gas adopting hydraulic fracturing method, the generated water blocking effect will have a big influence on capacity of shale gas. In order to explore effect degree of each influence element on water blocking effect, correlation of water blocking with those five are analyzed including permeability, porosity, irreducible water saturation, work pressure difference and gas-liquid interface. Using gray correlation analysis method, the results show： the damaging rate of permeability is considered as damaging degrees of water blocking, R01〉R03〉R0z〉R05〉R04. The correlations are ranked from the highest to the lowest： permeability, irreducible water saturation, porosity, work pressure difference and gas-liquid interfaeial tension at last. water blocking is conducted based on highest to lowest of correlations, which has certain significance on exhausting and mining of shale gas.