鄯勒油田煤系地层试注实践与认识

Pilot injection test on coalbed formation in ShanLe Oilfield.

鄯勒油田西山窑油藏储层属煤系地层,储层特低孔特低渗,天然能量弱,单井自然产能低,一般压裂后具有较好的工业开采价值,但地层压力、产能下降幅度快,弹性产率低,所以及时补充地层能量,是稳定产能、提高采收率的必要手段。根据油田实际,开展试注,探索注水开发可行性,是现实的确定能量补充方式的有效途径。通过定期注入优选的防膨剂,提高注入压力,实施定量注水,一年半来,试注井组油井产液能力稳定,地层压力下降幅度明显减缓,油井出现见效迹象,注水井端套管保持完好,实践证明在当前条件下注水开发是可行的。通过对鄯勒油田勒4-2井组试注一年半来井组动态反应,总结确定了煤系地层注水恢复能量的可行性,为鄯勒油田实施注水开发及国内同类型油田确定能量补充方式提供了详实的矿场试验资料。

The Xishanyao reservoir in Shanle oilfield is coalbed formation,which belongs to extremely low porosity and permeability reservoir.Wells have to be fractured to produce commercially.The productivity and pressure droped off quickly,so water injection to complement the reservoir energy was necessary to improve oil recovery and stabilize the production.By injecting clay stabilization periodically and increasing injection pressure,liquid production index of the pilot injection group had shown a stabilized status after the injection test started one and a half year ago,the declining extent of reservoir pressure was slowing up obviously.By analyzing the dynamic characteristics of the pilot injection group,water injection in coalbed reservoir is considered to be feasible.