摘要
针对裂缝性潜山油藏非均质性强、含水上升快、产量递减快、开发中后期高效开发难度大等问题，文中以渤海JZ油田为例，采用数值实验、大型三维物模实验及数值模拟方法，开展了裂缝性油藏不同储层条件下裂缝参数敏感性分析、剩余油分布规律、剩余油挖潜策略等方面的研究。结果表明：不同的裂缝发育特征对油藏生产规律影响不同，根据生产井产能特征将JZ油田储层划分为3类，不同储层条件下剩余油分布规律不同；整体上，裂缝系统采出程度较高，基质系统是主要的剩余油富集区。平面上，剩余油主要分布在物性差区、大裂缝周边的小裂缝及井网控制不完善区；纵向上，剩余油以“零星镶边状分布型”、“局部块状分散型”、“大裂缝窜流块状连续型”赋存为主。在剩余油认识的基础上，采用数值模拟技术并结合矿场实践，提出了一套适合3类储层的剩余油挖潜策略。JZ油田现场实践表明，采用该系列技术，油田近3 a含水上升率持续降低，实现3 a连续稳产80×104 t，相比常规稳定注水方案，预计提高采收率近5百分点。该研究对同类裂缝性潜山油藏的开发具有一定的指导意义。
Abstract
In view of strong heterogeneity, rapid rise of water cut, large decline of production and great difficulty of efficient development in the middle and late stage of development in fractured buried hill reservoirs, taking JZ Oilfield in Bohai Bay Basin as an example, numerical experiment, large-scale three-dimensional physical model experiment and numerical simulation method are used to carry out studies on the sensitivity analysis of fracture parameters, distribution law of remaining oil and potential tapping strategy of remaining oil under different reservoir conditions in fractured reservoir. The results show that different fracture development characteristics have different effects on reservoir production law. According to productivity characteristics of producing well , the reservoir in JZ Oilfield is divided into three types of reservoirs. The distribution laws of remaining oil are different under different reservoir conditions. On the whole, the recovery degree in fracture system is higher, and the remaining oil is mainly rich in matrix system. On the plane, the remaining oil is mainly distributed in areas with poor physical properties, small fractures around large fractures and areas with imperfect well pattern control. In vertical, the remaining oil mainly occurs in "sporadic marginal distribution type", "local massive dispersion type" and "large fracture channeling massive continuous type". Based on this understanding of remaining oil, a set of remaining oil tapping strategy suitable for three types of reservoirs is proposed by combining numerical simulation technology with field practice. The filed practice in JZ Oilfield show that with this series of technologies, the water cut increasing rate has been continuously reduced in recent three years, and the continuous stable production of 80×104 t in three years has been realized. Compared with the conventional stable water injection scheme, the oil recovery is expected to be improved by nearly 5 percentage points. This study results has certain guiding significance for the development of similar fractured buried hill reservoirs.
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