H油田为气顶边水油藏,以天然能量开发为主.目前该油田采出程度较大,剩余油分布零散且研究手段有限,油田挖潜难度大.为了认清该油田油水运移及剩余油分布规律,论证现阶段转变开发方式的可行性,基于二维物理模拟实验开展研究.结果表明:H油田衰竭开发后期剩余油主要分布在气顶高部位渗透率较低的储层中,转屏障注水和布调整井对采收率的提高均有一定的作用,但仍然不能弥补由于渗透率差异导致的剩余油分布特征.考虑到H油田气顶边水窄油环的特殊性,布调整井仍然面临成本高以及气窜和水窜的风险,对目标油田实施屏障注水井,措施实施后累增油4.8×104m3,井组提高采收率 4.9%.
The H oilfield is a gas cap edge water reservoir,mainly developed with natural energy.At present,the oilfield has a high degree of recovery,with scattered distribution of remaining oil and limited research methods,making it difficult to tap the potential of the oil-field.In order to understand the migration of oil and water and the distribution of remaining oil in the oilfield,and to demonstrate the feasibility of changing development methods at this stage,research was conducted based on two-dimensional physical simulation experiments.The results indicate that the remaining oil in the later stage of depleted development of H reservoir is mainly distributed in reservoirs with low permeability at high gas cap areas.Both barrier water injection and adjustment wells have a certain effect on improving oil recovery,but still cannot compensate for the distribution characteristics of remaining oil caused by permeability differences.Considering the particularity of the narrow oil ring at the edge of the gas cap in H oilfield,the deployment of adjustment wells still faces high costs and risks of gas and water channeling.Therefore,barrier injection wells are implemented for the target oilfield,and the cumulative increase in oil production after the implementation of measures is 4.8×104m3,with a 4.9%increase in oil recovery rate for the well group.