泌238断块凝胶与聚合物多轮次交替注入参数优化研究

Optimization of alternating injection with multiple rounds of gel and polymer in B238 Block

为改善下二门油田泌238断块水驱开发过程中窜流严重,开发效果变差的现状,实现进一步提高原油采收率的目的,在室内实验的基础上,运用数值模拟方法,系统地开展了水驱后凝胶体系与聚合物多级段塞交替注入参数优化及聚合物注入质量浓度差异化调整研究。研究结果表明,多轮次小段塞组合方式提高采收率效果优于低轮次大段塞组合方式,主体段塞为:0.08 PV(聚合物)+0.02 PV(凝胶)+0.06 PV(聚合物)+0.02 PV(凝胶)+0.06 PV(聚合物)+0.02 PV(凝胶)+0.06 PV(聚合物)+0.02 PV(凝胶)+0.06 PV(聚合物)+0.02 PV(凝胶)+0.06 PV(聚合物)的组合方式提高采收率值最高,提高采收率值为7.92%;注入井聚合物质量浓度差异化调整幅度为20%,即质量浓度值调整420 mg/L时,提高采收率出现拐点,随聚合物质量浓度调整幅度的继续增加,采收率增幅呈下降趋势。说明凝胶体系与聚合物交替注入驱油方法具备进一步开发剩余油的潜力,为同类油藏开发提供一定的技术参考。

In order to improve the current situation of serious water channeling and the poor development effect during the water flooding development of B238 Block in Xiaermen Oilfield,and further to enhance the oil recovery efficiency,the numerical simulation method has been carried out to systematically study the parameters optimization of the multi-stage slug injection system after polymer flooding and the differential adjustment of polymer injection concentration based on laboratory experiments.It is found that the combined small slug with multiple rounds is more effective than the large slug with less rounds.The main slug which increases EOR most is composed of 0.08 PV(polymer)+0.02 PV(gel)+0.06 PV(polymer)+0.02 PV(gel)+0.06 PV(polymer)+0.02 PV(gel)+0.06 PV(polymer)+0.02 PV(gel)+0.06 PV(polymer)and the EOR value is 7.92%.When the polymer concentration adjustment range of injection wells is 20%,that is,the concentration is adjusted to 420 mg/L,EOR reaches the inflection point.And with the continuous increase of polymer concentration adjustment range,the increase of oil recovery shows a downward trend.It shows that the gel system and polymer alternating injection method have the potential to further develop remaining oil,and provide some technical reference for the development of similar reservoirs.