苏丹穆格莱德盆地苏夫焉凹陷含油气系统特征

PETROLEUM SYSTEM IN THE SUFYAN DEPRESSION OF MUGLAD BASIN IN SUDAN

苏丹穆格莱德(Muglad)盆地位于中非巨型走滑断裂带的东端部,是一个大型中生代含油气裂谷盆地。苏夫焉(Sufyan)凹陷位于该盆地北区块的最北侧,下白垩统阿布加布拉(Abu Gabra)组是烃源岩、Abu Gabra组的三角洲砂体和本蒂组(Bentiu)组的河道砂岩是主要储集层;上白垩统达尔富尔(Darfur)群为区域盖层;油气圈闭类型主要为断背斜、断鼻和断块等。苏夫焉凹陷含油气系统纵向上划分为二个亚系统,第一套沉积旋回Abu Gabra组自生自储自盖亚系统及第一套和第二套沉积旋回组成的下生上储盖亚系统,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,它们都是本区有利的勘探组合。该凹陷中部构造带是油气有利聚集区带,有些良好的勘探前景。

The Muglad Basin in Sudan is located the eastern boundary of Central Africa Strike-slip Fault Zone,is a large Mesozoic petroliferous rift basin.The Sufyan Depression is located most north end in this basin.Lower Cretaceous Abu Gabra Formation is an effective hydrocarbon source rock.Favorable reservoir in this area is the Abu Gabra Formation channel sandbody in delta or fan delta.Upper Cretaceou Darfur Group is the region cap rock.The hydrocarbon trap types have fault anticline,fault nose and fault block etc.The Sufyan Depression has two petroleum subsystems vertically,among which Abu Gabra Fm subsystem has favorable assemblage with self generating,collecting and sealing.While the other petroleum subsystem is composed of Abu Gabra Fm source rock,Bentiu Fm channel sandstone reservoir and Darfur Group shale seal.Both they are favorable for exploration.The Central structure belt of the Sufyan Depression is most favorable for exploration.