苏丹穆格莱德盆地油气地质新进展与勘探新领域

New progress in petroleum geology and new field of exploration in the Muglad Basin,Sudan

苏丹穆格莱德盆地Bentiu组—Aradeiba组主力成藏组合构造油气藏勘探进入成熟期,可钻探圈闭日趋减少,勘探难度越来越大。通过成藏地质条件研究,结合近期的勘探实践,提出了浅层次生油藏、岩性油藏、基岩潜山油藏和天然气藏等4个勘探新领域;同时,明确了下步勘探的有利方向,即:Kaikang凹陷断阶带及凹陷内部的古突起是继续寻找浅层次生油藏的有利区,Fula凹陷、Bamboo凹陷、Sufyan凹陷及Neem南斜坡等地区是寻找岩性油藏的有利区,凹陷斜坡区或低部位被Abu Gabra组二段或四段烃源岩整体覆盖的潜山圈闭是寻找基岩潜山油藏的有利目标,Neem地区、Fula—Moga构造带、Sharaf—Abu Gabra构造带、Sufyan凹陷中央构造带Abu Gabra组五段构造圈闭是寻找大中型天然气藏的有利目标。

The primary reservoir-seal assemblage （RSA） of the Bentiu-Aradeiba formations in the Muglad Basin, Sudan is becoming over-explored, which significantly reduces inventory of drillable prospects and makes further exploration more difficult. Based on our reservoir forming study and recent drilling data, we propose that there are four novel exploration domains in the basin, i.e., the secondary oil reservoir in shallow formations, lithological oil reservoir, buried basement hill oil rcscrwir, and gas reservoir below source rocks. The four domains arc characterized as follows： the fault step zones and palaeo-uplifts of the Kaikang sub-basin are the favorable targets for the secondary oil reservoir in shallow formations; the Fula, Bamboo and Sufyan depressions and Necm South slope are potential candidates for the lithological oil reservoir; the basement hills blanketed by AG2 and/or AG4 source rocks in the center and slope of depressions should be the first choice for buried basement hill oil reservoir; and finally, the AG5 structural prospects distributed in the Neem area, the Fula - Moga and Sharaf - Abu Gabra structural zones and the central structural zone of the Sufyan depression, could be selected as favorable targets for the large - middle- scale natural gas reservoir below source rocks.