沉积相与岩相相结合的三维地质模型建立

A three-dimensional geological model combining sedimentary facies with lithofacies

针对在相控建模中沉积相控只能在平面上起到约束作用而岩相控制的属性模型与沉积相匹配程度不高的局限,以Z油田为例,建立了沉积相与岩相相结合的三维精细地质模型,即综合运用单井相与平面沉积相相结合的方法,在变差函数分析的基础上对各沉积微相变差函数进行调节,利用序贯指示算法模拟空间上的相模型;再根据相模型的控制建立属性模型;最后利用容积法计算出油田地质储量。对比结果表明,利用上述方法计算出的Z油田地质储量与资料提供的地质储量仅相差0.6%,验证了本文模型的准确性。

In the facies-controlled modeling, the sedimentary facies can only provide an areal constraint and is quite low in its matching with the lithofacies-controlled attribute model. Therefore, Z oilfield was taken as an example to build a three- dimensional and refinded geological model combi- ning sedimentary facies with lithofacies. First, a method to combine single-well facies with areal sedimentary facies was comprehensively applied to adjust the variation function of each sedimentary microfacies based on an analysis of variation func- tion, and a sequential indicator algorithm was used to simulate a facies model in space. Then an attrib- ute model was built under the control of the facies model. Finally, the oil reserves were calculated for Z oilfield by using a volume method. The result shows that the oil reserves which calculated by this method has only 0.6% difference with the existing data, which proving the accuracy of this three-di- mensional geological model.