高含水油藏细分注水层段组合优选方法研究

Study on Layer Combination Optimization Method of Subdivision Water Injection in High Water-cut Reservoirs

针对高含水期油藏层系细分后层间干扰依然严重、层间矛盾突出、注入水无效循环等问题,细分注水技术为提高注水利用率和改善注水开发效果提供了有效手段,其成功的基础是根据各小层物性资料和开发动态确定合理的层段组合。为此,采用最优分割法,综合考虑影响细分注水层段组合的各种动静态因素,将判别分析中的费歇准则思想与反映细分注水开发效果的各种指标以及主客观权重方法相结合,引入层段直径概念,建立定量化的细分注水层段划分方法,从而快速地确定最优层段划分方案。实例分析与油藏数值模拟表明,该方法结果可靠、计算简便,便于实际操作,有助于指导多层油藏高含水期的细分注水调整。

In the high water cut period, even after subdivision of reservoir layers, serious problems still remain, such as inter- layer conflict and inconsistency and invalid water cycle, to solve them, subdivision water injection is an effective approach of improving the development effect and water-flooding sweeping efficiency. The key to success of subdivision water injection is to determine the reasonable combination of layers according to the reservoir properties and development situations of each layer. This article adopts optimal segmentation methods, considering the Fisher principle with expertise and the various indicators reflecting development effect. In addition, it introduces the concept of interval diameter considering the various factors to determine the optimal scheme for layer division, which can reflect the contradiction between layers, such as permeability, producing degree, absorption strength, restraining barrier and so on. The comparison of instance analysis with the results of reservoir simulation shows that this method is simple but reliable water cut stage. and can help adjust the subdivision water injection at high