鄂尔多斯盆地延长探区上古生界石千峰组沉积微相特征研究

摘要

Based on the study of exploration well datas which contain the core observation、description and well logging in the Yanchang field of Ordos Basin, the Shiqianfeng Formation was able to identified two sedimentary systems;delta and lacustrine facies. Shiqianfeng Formation was divided into five groups that are q5, q4, q3, q2 and q1 since the bottom. The delta front microfacies of delta facies is the mainly facies for q5. The underwater distributary channel and mouth bar are of the gas reservoir,which had been found out nature gas in some well since 2006. It is of good prospects for gas exploration. The coastal lacustrine microfacies of lacustrine facies is the mainly facies for q4-q1. Mudstone is the chiefly lithology, the thick mudstone is well capping for the underlying formations which are of gas-bearing reservoir. Therefore, it is suggest that compatibility exploration q5 when it is explored and developed the underlying gas-bearing reservoirs. The exploration cost will be declined and the gas production yield will be increased in Yanchang field.%分析了延长探区内已有探井的录井、测井和岩心观察结果等资料后认为，石千峰组沉积相可分为三角洲相和湖相。石千峰组自下至上分为千5、千4、千3、千2和千1五个段。千5段以三角洲相、三角洲前缘亚相为主，其中的水下分流河道和河口坝微相为主要含气相带。2006年起，在此处见到了工业气流。由此可见，此处具有良好的勘探前景。千4～千1四段以湖相滨、浅湖亚相为主，主要发育泥岩，巨厚的泥岩是千5及其以下气层的良好盖层，所以，建议在下石盒子组、山西组等下覆主力层勘探开发时一并兼探千5。这样做可节约成本，提高产量。