高pH值工作液对油气层的损害

Study on hydrocarbon reservoir damage caused by high pH value working fluid

东河塘石炭系储层由于大量高pH值工作液侵入被严重损害。对岩心碱敏损害进行了评价,分析了碱敏损害机理。结果表明,pH值大于9的工作液对储层造成严重的碱敏损害。其实质是粘土矿物(主要为高岭石)颗粒在高pH值盐水中分散并释放微粒,导致微粒堵塞孔喉,造成对储层的损害。储层碱敏损害是不可逆的。

Hydrocarbon reservoir damage caused by high pH value working fluid in Donghetang reservoir is evaluated. Reservoir damage mechanism is analysed. It is shown that clay mineral can disperse in the working fluid with high pH value and the dispersed particles will plug the pore and throat. Tests indicate that working fluid with high pH value can cause serious reservoir damage. The pH value of working fluid should be limited below 9.