低渗透油藏高含水期强化微泡沫体系研究

The optimization in enhanced micro foam system in high water cut in low permeability reservoir

为解决安塞油田低渗透油藏开发存在的高含水井多、产能损失严重等问题,对强化微泡沫体系的优化及提高采收率方式等进行了可行性研究;应用Waring Blender方法和泡沫驱动态模拟装置评价微泡沫体系驱油规律和影响因素。结果表明:自主研发的QHWP-121阴非离子微泡剂在模拟地层水中的泡沫体积为850mL,半衰期为380min,泡沫综合指数为323 000mL·min,泡沫质量0.65,泡沫性能最好。油藏条件下,驱油规律主要表现为非均质性改善、压力上升、动用孔喉半径增多、堵水不堵油,强化微泡沫体系驱油影响因素主要与油藏配伍性、浓度、渗透性和气液比相关。本研究表明,强化微泡沫驱油效果的好坏主要与强化微泡沫体系和油藏的配伍性具有直接关系,推荐该体系在安塞油田王窖区块的现场应用浓度为0.5%,气液比在1∶1~2∶1之间,渗透率适应范围(10~10 000)×10^(-3)μm^2。

To tackle the problems of high water content and capacity loss in the development of low permeability reservoirs in Ansai oilfield,the feasibility study was carried out in the optimization of strengthen the micro-foam system and the improving mode of oil recovery.The oil displacement law and the influencing factors of the micro-foam system were evaluated by Blender Waring method and the foam flooding dynamic simulation device.The following results were obtained.For a self-developed non-anionic micro-bubble agent QHWP-121,the foam volume was850 mL,the half-life was 380 min,the foam composite index was 323 000 mL·min,and the foam quality is 0.65.In this case,the foam is the best.Under the condition of oil reservoir,theoil displacement law is mainly manifested by improved heterogeneity,increased pressure,increased radius of pore throat,water shutoff but no oil shutoff and the oil can pass.The influencing factors in oil displacement of the micro-foam system were mainly related to the compatibility,concentration,permeability and gas/liquid ratio of the reservoir.The results revealed that the efficiency of oil displacement is mainly related to the compatibility between the strengthening micro-foam system and the reservoir.The suitable parameters used in the field practice are recommended as following.The concentration of micro-foam system is 0.5%,the gas-liquid ratio is 1∶1~2∶1,and the permeability is（10~10 000）×10-3μm2,which can provide a basis for enhanced micro foam flooding field in low permeability reservoir of Wangyao operation area in Ansai oilfield.