苏丹国努加拉凹陷含油气系统特征与勘探

Petroleum system in Nugara Depression of Muglad Basin in Sudan and exploration

目的探究穆格莱德盆地努加拉伸展断陷含油气系统的特征,并分析含油气系统对油气藏的控制作用。方法在对下白垩系阿布加布拉组上段有效烃源岩、储层类型及生储盖组合等条件分析的基础上,用含油气系统的理论划分努加拉伸展断陷含油气系统并进行分析。结果把努加拉凹陷从平面上划分为东、西部两个含油气系统,东、西次凹是生油中心;纵向上划分为两个亚系统,其中有第一套旋回Abu Gabra组自生自储自盖亚系统及由第一套和第二套旋回组成的下生上储盖组合,即Abu Gabra组生油岩、Bentiu组河道厚砂岩储层和Darfur群泥岩盖层组合。结论努加拉凹陷含油气系统总资源量为21.6×108t,圈闭资源量11.9×108t,尚有较大的资源潜力,中央隆起带及其两翼、西斜坡是有利区带,有良好的勘探远景。

Aim To study the petroleum systems of Nugara Depression of Muglad Basin in Sudan,analyse the characteristic of the petroleum systems and oil reservoir in the Nugara depression.Methods On the basis of comprehensive analying A bu Gabra formation developed in early Cretaceous is an effective hydrocarbon source rock etc,Favorable reservoir,the characteristic of the Petroleum systems of Nugara depression are analyzed according to the theory of Petroleum systems.Results Nugara Depression has two petroleum systems in east and west horizontally.East and west sub-depressions are the centers of source rocks.There are two oil and gas sub-systems vertically,among which Abu Gabra sub-system has favorable assemblage with self generating,collecting and sealing.While the other hydrocarbon subsystem is composed of Abu Gabra source rock,channel sandstone reservoir in Bentiu and shale seal in Darfur Group.They both are favorable for exploration.Conclusion Total resources in Nugara Depression is 21.6×10^8t and trap resources 11.9×10^8t.Saraf-Abu Gabra rift belt which is most favorable for exploration which is a considerable exploration target with good prospect.