Ⅲ类油藏聚合物驱注入参数研究与应用

Study and application of polymer flooding injection parameters in classⅢreservoir

中原油田经过三十多年的开发,油藏已进入高采出、特高含水阶段,采出程度接近水驱标定采收率,常规水驱难以进一步提高采收率。聚合物驱(复合驱)已在I、II类油藏成功工业化推广,但是在Ⅲ类高温高盐油藏的应用仍处于攻关试验阶段。基于文明寨油藏储层物性,利用物-数模一体化技术开展聚合物注入参数的研究,通过对注入浓度、注入量、注入速度及注入方式的优化以实现“强提压,深注入”的目标。结果发现,对于文明寨油藏明16块的最佳注入参数为注入质量分数0.20%,注入速度0.11 PV/a;注入方式依次为调剖段塞、聚合物驱主体段塞、后置段塞,段塞体积比为1∶4∶1,其中聚合物驱主体段塞采用交联聚合物-聚合物交替注入。研究结果在中原油田Ⅲ类高盐油藏成功应用2井次,截至2022年4月13日已累计增油815.7 t,为聚合物驱技术在中原油田的矿场应用提供了新的理论依据。

After more than 30 years of development in Zhongyuan oilfield,the reservoir has entered the stage of high recovery and extra-high water cut.The recovery degree is close to the calibration recovery factor of water flooding,and it is difficult to achieve conventional water flooding.Polymer flooding(composite flooding)has been industrialized in classⅠand classⅡreservoirs,and classⅢhigh temperature and high salt reservoirs are still in the stage of key research.In this paper,based on the reservoir physical properties of Wenmingzhai reservoir,the polymer injection parameters were studied by using the object-numerical-analog integration technology.The goal of“strong pressure increase and deep injection”was achieved by optimizing the injection concentration,injection volume,injection rate and injection mode.The results showed that the optimal injection parameters for Ming 16 in Wenmingzhai reservoir were as follows:injection concentration was 0.20%,injection rate was 0.11 PV/a,injection mode was profile control slug,polymer flooding main slug,and postslug,and the volume ratio of slug was 1∶4∶1.Cross-linked polymer-polymer alternating injection was used for polymer flooding main slug.The research results had been successfully applied in classⅢhigh salt reservoirs in Zhongyuan Oilfield for 2 wells,and the cumulative oil production had increased by 815.7 t as of April 13,2022,which provided a new theoretical basis for the field application of polymer flooding technology in Zhongyuan oilfield.