缝洞型碳酸盐岩油藏流动单元概念和研究方法探讨

流动单元对于提高油田采收率具有很大的实际意义,该项研究在砂岩油藏研究中已取得较大进展。对于缝洞型碳酸盐岩油藏,由于岩石结构构造、成岩后生作用、构造断裂作用、溶蚀作用等多因素对储集空间的影响,已有的流动单元概念及研究技术方法难于应用。以塔河油田为例,针对缝洞型碳酸盐岩地质特征,论证了碳酸盐岩储层渗流屏障的存在及其类型,探索性提出区别于砂岩油藏的缝洞型碳酸盐岩储层流动单元的概念。提出的研究思路和方法包括;油藏压力趋势分析法、井间生产干扰分析法、流体性质差异分析法、井间干扰试井法。结合储层发育特征,初步建立了缝洞型碳酸盐岩流动单元的划分标准。

Study and discussion on flow units of fractured carbonate reservoir

Flow units, which has made much progress in the study of fractured carbonate reservoir, has great practical significance for improving oil recovery ratio. As for the fracture - cavity carbonate reservoir, the conventional theory of flow units is hard to apply because of the complex influence of tectonic structure, post diagenesis, tectonic fracturing and dissolution. Based on the typical geological character of fracture - cavity carbonate reservoir in Tahe oil field, this article discussed the existence and variance of seepage barrier and brought forward the concept of flow units, which is quite different from that of fractured carbonate reservoir. The proposed research clue and methods included: pressure trend analysis, production interference analysis, fluid PVT differences, and interference well test. Combined with the reservoir features discussed above, we has established dividing criterion of fractured carbonate reservoir flowing unit.