华池油田三角洲前缘砂体展布的三维建模

Stochastic modeling of sand-body of deltaic front in Huachi Oilfield

目的利用三维建模方法预测三角洲前缘砂体有利储层的分布。方法利用序贯指示模拟法(SIS)对华池油田长3层段三角洲前缘水下分流河道及河口坝微相的砂岩岩相及砂体展布进行随机模拟。结果砂岩岩相模拟的三维实现表明,长31、长32、长33小层中以长33小层砂岩最为发育;砂体展布的三维模拟结果表明,长33小层砂体厚度最大,主砂体主要为东北—西南向展布的条带,主砂体向前伸展并演化为三条次级砂带。砂岩岩相与砂体的三维模拟结果在该区勘探实践中得到了较好的验证。结论在主砂体上砂岩厚度大、物性好,常常发育优质储层。

Aim Using stochastic modeling to predict the spacial location of the main sand-body of dehaic front, and then to make prediction of the potential reservoir. Methods Taking Huachi Oilfield of Ordos Basin as the example, the stochastic method of Sequence Indicator Simulation （SIS） was selected for modeling the lithofaeies and distribution of the sandstone which was composed of submerged distributary channels and river mouth bars in delta front of Chang 3. Results According to the results of sandstone lithofacies modeling, the distribution of the sandstone of Chang 33 was the most widespread, and the continuity and connectivity of the sandstone of Chang 33 was the best in the three layers of Chang 31 , Chang 32 and Chang 33. The results of sand-body modeling revealed that the thickest sandstone also lay in layer of Chang 33. The main sand-body of Chang 33 was like a band with the direction from northeast to southwest. It extended forward and then split into three secondary sand-bands. The predictions of the sandstone lithofaeies and the distribution of main sand-body matched well with the exploration facts. Conclusion In the main sand-body band, high-quality reservoir always existed in the places where the sandstone was thick and its corresponding property was high.