海上复杂断块油藏动态连通性分析方法及应用——以涠洲A油田A2井区为例

Dynamic connectivity analysis method of complex fault block reservoir of offshore oilfield and its application-taking the A2 well region of Weizhou A oilfield as an example

海上复杂断块油藏具有储层非均质性强、砂体连通性比较复杂等特征。同时,鉴于海上油田投资成本高昂,缺乏试井、示踪剂、地球物理等关键资料导致连通性分析困难、剩余油分布预测难度大。因此,针对以上问题,以油井生产系统为基础,将物质平衡方程和不稳定渗流理论相结合,并考虑水侵影响和产量递减的变化,提出了动态连通性分析方法。该方法仅需利用生产动态资料便可得到动储量、动用范围及水体规模,从而分析储层连通性,指导复杂断块油藏挖潜研究。选取涠洲A油田A2井区进行了现场应用,并利用数值模拟法进行了验证,结果表明储层是连通的,对于类似海上复杂断块油藏,该方法具有较好的推广应用价值。

Complex fault block reservoirs of offshore oilfield are characterized by strong het- erogeneity and complex connectivity. At the same time, owing to the high investment cost, lack of testing, tracer, geophysical and other key informations, it leads to the difficulty of connectivity analysis, and it is hard to predict the distribution of remaining oil. For this problems, based on the oil well production system, combined material balance equation with unstable seepage theory, with the consideration of the influence of water influx and yield de- creasing changes, the dynamic connectivity analysis method is proposed. With this method, the dynamic reserves, producing area and the size of water body can be acquired by using dynamic production data only. Thus analyses of reservoir connectivity can be conducted, which would guide the study of exploration potential. The technology has been applied to A2 well region of Weizhou A oilfield. Verified by numerical simulation, studies have shown thatthe reservoir is connected. This method also has a good application value in the similar off- shore complex fault block oil reservoirs.