大牛地气田回注井地层敏感性实验研究

大牛地气田W-4污水回注井储层结构致密,岩心孔隙度在10%～15%,属于低孔隙度、低渗透率砂岩储层。该井在污水回注过程中,回注压力急剧升高,影响正常回注。针对该井回注压力升高过快的问题,进行了储层敏感性实验研究。结果表明:W-4井储层具有弱速敏、强水敏和弱碱敏,且随着回注水水量的增大,岩心渗透率逐渐降低,影响回注生产作业。根据实验研究结果,提出了对策措施,对于解决压力升高的问题具有指导意义。

Research on formation sensitivity in the Daniudi gasfield reinjection well

In Daniudi gas field,the reservoir structure of W-4sewage reinjection well is fine and close.The core porosity is 10% ～15%,which belongs to low porosity,low permeability sandstone reservoir.During the process of water ’ s reinjection,injection pressure increases sharply,which affects the normal injection.Based on the problem of reinjection pressure rapid increasing of the well,the formation sensitivity was studied experimentally.Results show that W-4well ’ s reservoir bed is weak velocity sensitivity,strong water sensitivity and weak alkaline sensitivity,and the core permeability decreased gradually with the water content increasing,which affected the injection production.On the basis of the experimental results,the countermeasures to solve the problem of pressure rise are put forward which has guiding significance for solving problem of pressure rise.