油藏流场定量表征方法及应用

复杂断块油藏经过长期注水开发，导致油藏流场分布愈加复杂，逐渐形成优势流场和弱势流场。优势流场区无效注水循环严重，弱势流场区注水却难以波及，油藏开发效果差，开发调整困难。为此，以黄骅拗陷南部的沧东凹陷枣南孔一段枣Z断块为例，基于真实油藏建立概念模型，开展了复杂断块高含水油藏流场定量化研究。根据油藏静、动态参数对油藏流场的影响程度，优选出渗透率、地层压力梯度、含油饱和度、面通量4个参数作为油藏流场的主要表征参数。在此基础上，基于模糊数学理论建立油藏流场强度计算模型，从而确定了目标油藏的不同类型流场强度划分界限，并针对不同流场类型制定了流场调整技术对策。目标油藏的流场调整实践结果表明，应用油藏流场定量表征方法能有效描述高含水期油藏流场特征，有利于指导油藏层系组合调整、注采井网重构，进而改善油藏注水开发效果。

Quantitative Characterization Method and Application of Reservoir Flow Field

Due to long term washing of water injection in the complex fault block reservoirs, the distribution of reservoir flow field would be more and more complicated and it results in forming different types of reservoir flow field with different intensities. In regions of high intensity of reservoir flow field, invalid water injection is very serious. But water injection cannot reached the regions of low intensity easily. It results in a poor efficiency of reservoir development and makes it hard to adjust reservoir development. Due to the above reasons, taking a case Block Zao Z of the first member of the Kongnan, Cangdong Sag, south of Huanghua Depression, the simulation model was modeled to study quantitatively reservoir flow field at high water cut stage. According to the influence on reservoir flow field, the primary characterization parameters were selected from some static and dynamic parameters, including permeability, pressure gradient, oil saturation and surface flux. A calculation model of intensity of reservoir flow field was proposed by the theory of fuzzy mathematics. The ranges of different types of reservoir flow field were determined on the study reservoir. And then technical strategies of reservoir flow field adjustment were given in different types of reservoir flow field. The implement results of flow field adjustment of the study reservoir show that the characterization method of reservoir flow field could be applied to a correct understanding of the characteristic of reservoir flow filed at high water cut stage. It is helpful to guide to adjust layer series and well groups and to improve effect of reservoir development.