稠油油藏三元复合驱参数优化实验研究

Experiment Study on Parameter Optimization of ASP Flooding in Heavy Oil Reservoirs

针对扶北2稠油区块在蒸汽驱过程中采收率低、见效差的问题,提出了减氧空气+高温泡沫剂+蒸汽三元复合驱方案,并对其进行参数优化研究。通过优选出的最佳注入参数,采取并联三管填砂模型模拟地层纵向非均质性,对该三元复合驱采收率进行研究。结果表明,在渗透率级差为3.20,高温泡沫气液比为1∶1,以混合注入的方式,最佳泡沫剂注入量为0.25倍孔隙体积,水驱至含水率为50%,回压为5 MPa时,减氧空气+高温泡沫剂+蒸汽三元复合驱最终采收率为63.8%,比蒸汽驱采收率提高了28.9个百分点。研究认为,通过减氧空气+高温泡沫剂+蒸汽三元复合驱能有效地抑制汽窜,使中、低渗储层原油动用程度增大。该项研究为同类稠油油藏进一步提高原油采收率提供了借鉴。

The steam flooding in the heavy oil reservoirs of Fubei 2 Block is poor in application effect with low recovery factor.To solve these problems,ASP flooding scheme of oxygen-reducing air,high temperature foam and steam was proposed and the related parameter optimization was studied.Then,based on the selected optimal injection parameters,the vertical heterogeneity of strata was simulated in the sand packed model with three tubes in parallel and the recovery factor of ASP flooding was investigated.It is shown that the ultimate recovery factor of ASP flooding of oxygen-reducing air,high temperature foam and steam is 63.8%which is 28.9 percentages higher than that of steam flooding when combination injection is carried out,the permeability contrast is 3.20,the gas/liquid ratio of high temperature foam is 1∶1,the optimal foam agent injection is 25%pore volume,water cut of water flooding is 50%and back pressure is 5 MPa.It is concluded that ASP flooding of oxygen-reducing air,high temperature foam and steam can inhibit steam channeling effectively and increase the oil producing degree of moderate and low permeability reservoirs.The research can be used as the reference for enhancing the recovery factor of similar heavy oil reservoirs.