苏里格气田中下二叠统砂岩储层碱损害研究

RESEARCH ON ALKALI DAMAGE IN MIDDLE TO LOWER PERMIAN SERIES SANDSTONE RESERVOIR OF SULIGE GAS FIELD

为减小苏里格气田在勘探开发过程中造成的储层损害,提高低渗气藏储层的产能,针对致密砂岩储层的碱损害进行了实验研究,分析了碱损害机理及影响因素。结果表明,pH值为9的碱液对储层损害程度为弱,与储层中高岭石含量高且晶体较大有关。pH值为12的碱液对储层不仅无损害,反而能大幅度地提高储层渗透率,这与强碱对高岭石的溶蚀有关。最后提出了可以用强碱改造纯气藏储层,在压裂过程中可用强碱作为前置液。

In order to reduce the reservoir damage in exploration and exploitation process in Sulige gas field,and to improve the production of the low permeability gas reservoir,the experimental research about alkali damage in tight sandstone reservoir has been done,and the alkali damage mechanism and influencing factors has been analyzed.The results showed that alkali liquor with pH 9 has a weak damage effect on reservoir because of the high content and the large crystal of the kaolinite.Alkali liquor with pH 12 do not damage reservoir,conversely it can greatly improve the permeability of the reservoir because it can dissolve the kaolinite.Finally,it is pointed out that high pH value alkali liquor can be used to reform pure gas reservoir,and as ahead fluid during fracturing.