塔北隆起哈拉哈塘凹陷石油地质特征与油气勘探方向

Petroleum geologic characteristics and exploration orientation in Halahatang Depression of Tabei uplift

哈拉哈塘凹陷具有较好的石油地质条件,发育寒武系和奥陶系2套烃源岩,其中中上奥陶统烃源岩是一套良好油源岩,目前主要处在中等成熟演化阶段;发育多套储盖组合,其中东河砂岩、角砾岩段与上覆石炭系卡拉沙依组泥、灰岩的储盖组合及奥陶系灰岩与上覆上奥陶统达西库木组泥岩及志留系柯坪塔格组下部泥岩的储盖组合较为有利。海西期后一直处于构造相对高部位,古生界是轮南低凸起的组成部分,是油气运移的指向区;盖层较为发育,晚加里东—早海西期油气保存相对较好。

In order to investigate the conditions of hydrocarbon accumulation, the characteristics of petroleum geology have been analyzed in Halahatang area. There developed Cambrian and Ordovician source rocks. The Middle-Upper Ordovician source rocks are good and now mainly in the medium mature evolutionary phase. There are several series of reservoir-seal assemblages. The one consisted of Carboniferous Donghe sandstone, breccia and overlying mudstone and limestone, and the other one consisted of Ordovician limestone and Silurian mudstone are more favorable. Palaeozoic is a nose structure in the westward plunging end of Lunnan lower uplift. The nose structure has always been in the relatively higher position of structural belt since Hercynian as the oriented region of hydrocarbon migration. Several series of cap rocks developed well, which have good conditions for late Caledonian-early Hercynian hydrocarbon preservation. The results obtained show that there is a good exploration prospect in Halahatang area.