苏丹Fula坳陷白垩系AG组沉积特征

Sedimentary characteristics of the Cretaceous AG Formation in Fula Depression,Sudan

苏丹Fula坳陷白垩系AG组为典型的湖相裂谷盆地沉积。白垩系AG组油气资源丰富,随着勘探和开发的深入,需要分析沉积特征及有利砂体展布规律。为此,利用钻井、地震等资料,在层序地层划分基础上,开展岩心分析、测井相及单井相分析,根据地震相确定沉积相,建立沉积模式,进而寻找油气勘探有利区。研究发现,AG组主要发育扇三角洲、三角洲、湖相砂岩、泥岩沉积,其中扇三角洲前缘亚相、三角洲前缘亚相水下分流河道、河口坝微相和浊积扇等相带的砂体可作为有利储层,是岩性—地层圈闭发育的有利勘探区域。该成果可为下一步油气勘探提供指导。

The Cretaceous AG Formation in Fula Depression is a typical lacustrine rift basin deposition with rich oil and gas resources.With the deepening exploration and development,it is necessary to analyze the sedimentary characteristics and distribution patterns of favorable sand bodies.To this end,based on sequence stratigraphic division,this paper conducts core analysis,well logging facies,and single well facies analysis by drilling and seismic data to determine sedimentary facies according to seismic facies,build sedimentary models,and then search for favorable areas for oil and gas exploration.The results show that the AG Formation mainly develops fan delta,delta,lacustrine sandstone,and mudstone sedimentary facies.Sand bodies carried by subfacies of fan delta front,underwater distributary channels in subfacies of delta front,mouth bar microfacies,and turbidite fan can serve as favorable reservoirs and are favorable exploration areas for the development of lithologic stratigraphic traps.The results can provide guidance for further oil and gas exploration.