渤海A油田转注方案研究及实施效果分析

Study and effect analysis of the injection scheme of oil wells in Bohai A Oilfield

渤海A油田具有高地饱压差、低黏的特点,投产后衰竭开采22年,地层压力由29.50 MPa下降到注水前的21.58 MPa,低于22.50 MPa的原油饱和压力,油井脱气严重,产量递减明显。为了尽快恢复地层压力,在建立精细地质模型的基础上,采用数值模拟软件对5口先期排液井转注时机以及转注后注采比进行了数模研究。结果表明,油井转注越早,地层压力恢复越早,累积产油量越多。在注水初期,以1.05的日注采比注水,既能使地层压力得到有效恢复,又能使油田注水后期取得较高采收率。该研究结果可有效指导油田转注方案的实施。

Bohai A Oilfield is characteristic of high pressure difference between formation pressure and saturated pressure and low viscosity.After depletion and production for 22 years,the formation pressure drops from 29.50 MPa to 21.58 MPa before water injection,which is lower than the saturated pressure of crude oil 22.5 MPa,and the degassing of oil well is serious.In order to recover the formation pressure as soon as possible,this paper carries out the numerical simulation study on the injection occasion of the transfer of the five oil wells and the injection-production ratio after the transfer with the numerical simulation software based on the establishment of the fine geological model.The results show that the earlier the oil well transfer,the earlier the formation pressure recovery time is,the more cumulative oil production is.In the initial stage of water injection,the injection of water with a daily injection ratio of 1.05 can not only effectively recover the formation pressure,but also achieve higher recovery rate in the later stage of oilfield water injection.The results of this study can effectively guide the implementation of oilfield transfer programs.