苏丹Fula油田成藏规律与油气分布

Reservoir formation and oil and gas distribution of Fula Oilfield,Sudan

Fula凹陷Fula油田是苏丹Muglad盆地主要的产油气区之一。Fula凹陷经历了早白垩世、晚白垩世末和第三纪3期裂陷作用,第一裂陷期沉积的AG组泥岩为主力烃源岩;Aradeiba组、Bentiu组、AG组上段是主要含油层系;反向断块(断鼻)是主要圈闭类型。深切入AG组的大断裂是油气纵向运移的主要通道;Aradeiba组泥岩的侧向封堵是形成Aradeiba组和Bentiu组油藏的关键控制因素;AG组长期继承性发育的古隆起带是油气富集的有利场所,AG组上段泥岩对储集层的侧向和垂向有效封堵是形成AG组油气藏的决定性控制因素。Aradeiba组油藏为单一的层状油藏;Bentiu组油藏油水分布比较复杂,油水界面倾斜;AG组油气藏为层状油气藏,纵向上存在多套油气水系统。

Fula Oilfield in the Fula sag is one of the main petroleum-producing areas in the Muglad basin. The Fula sag suffered three faulted depressions in Early Cretaceous, Late Cretaceous and Tertiary. AG shale formation deposited in the first depressed period is the main hydrocarbon source, and Aradeiba, Bentiu and upper AG Formations are the main oil-bearing series; reverse fault block （nose-type） is the leading trap; the big fault cut into the AG Formation is the main channel for migration vertically; the lateral sealing of shale in Aradeiba Formation is the key control factor in forming the Aradeiba and Bentiu reservoirs; the successively developed palaeohigh in the AG Formation is the favorable hydrocarbon concentration area, the effective lateral and vertical seals by the shale in the upper section of AG are the crucial factors for the AG reservoirs. Aradeiba Formation is a single bedded reservoir; Bentiu Formation is a reservoir with complex oil-water distribution and tilted oil/water interfaces; AG Formation is a layered reservoir with multiple water/oil/gas systems vertically.