甲醇改善致密砂岩气藏水锁伤害的实验研究

Experimental research on methanol improving tight sandstone gas reservoir water locking damage

利用水力压裂开发致密砂岩储层过程中,由于储层胶结致密,水敏性粘土矿物含量高,压裂液滤失过程中容易引起储层的水锁伤害,抑制油气产出。将甲醇添加在压裂液中,利用甲醇的互溶性强、沸点低、易挥发的特性,将吸入到岩芯基质孔隙和微裂缝中的压裂液滤液携带出来,缓解水锁伤害,降低束缚水饱和度。

Tight sandstone reservoir is developed during hydraulic fracturing process,because of compact cementation reservoir and water sensitivity high clay mineral,which is easy to cause water locking damage of fracturing fluid filtration into reservoir,in turn inhibiting oil and gas output.Adding methanol in fracturing fluid,using its strong solubility of methanol,low boiling point and volatile inhalation to core matrix pore and micro cracks,methanol in the fracturing fluid filtrate can carry out water phase,which alleviates the water locking damage and reduces the irreducible water saturation.