中非多赛奥盆地白垩系油气成藏特征

Hydrocarbon Accumulation Characteristics of Cretaceous Strata in Doseo Basin of Central Africa

为深入认识多赛奥盆地油气成藏规律,以含油气盆地油气成藏理论为指导,结合盆地构造演化和沉积体系发育特征,对多赛奥盆地油气成藏条件进行逐一分析,结合钻井失利原因剖析,确定成藏主控因素,建立研究区油气成藏模式,确定油气富集有利区带。研究表明,多赛奥盆地成藏条件优越,烃源岩厚度大,热演化程度高,生烃潜力大,发育多套储盖组合;盆地呈现“深凹双向供烃、断层+砂体作为疏导体系向斜坡带构造圈闭供烃、深水砂体对接油源窗口直接供烃,油气近源运聚,深部岩性与浅部构造双类型甜点成藏”的特点,其中南部缓坡带为下步优势油气勘探区。

In order to study the law of oil and gas accumulation in Doseo Basin,based on the theory of oil and gas accumulation in oil and gas-bearing basins,combined with the structural evolution of the basin and the development characteristics of the sedimentary system,the conditions of oil and gas accumulation in Dosaio Basin were analyzed one by one,combined with the analysis of the causes of drilling failures,the main controlling factors for accumulation were determined,and a oil and gas accumulation model in the study area was established,favorable oil and gas enrichment zones were determine.The research shows that Doseo Basin has superior reservoir forming conditions and great hydrocarbon generation potential,it developes many sets of reservoir-cap combination.The basin is characterized by“two way hydrocarbon supply in the depression area,fault&sand body as the migration system to supply hydrocarbon to the structural trap in the slope zone,deep-water sand body directly supplied hydrocarbon by the downdip source,the hydrocarbon migration and accumulation with close distance,the reservoir includes deep lithology and shallow structure type”.The southern gentle slope zone is a favorable exploration area.