鄂南镇泾地区延长组油气富集主控因素及勘探方向

通过对已发现油气与有利相带、局部构造、断裂及裂缝分布等关系的分析,结合试油资料与砂体厚度、储层物性与录井显示关系的统计分析,开展了油气富集主控因素研究,提出了本区延长组油气富集"三元主控"的地质新认识--有利相带、局部构造背景、断裂及裂缝共同控制油气富集;油气主要富集在三角洲前缘水下分流河道砂体中;北西-南东宽缓鼻状构造高部位是油气富集区;垂直缝及高角度斜交缝是研究区延长组主要的有效裂缝。断裂及裂缝控制油气富集。长6和长8已发现油藏和规模储量主要分布在断距较大的F₂和F₃断裂带的附近。并指出了下步勘探的有利方向,即区块东南部局部鼻状构造、断裂及裂缝发育带和三角洲前缘水下分流主河道砂体叠置区是该区油气最富集的地区。

Main factors controlling hydrocarbon accumulation and favorable exploration targets for the Yanchang Formation in Zhenjing area, south Ordos Basin

Through analyzing the relations between petroleum discoveries and distributions of the favorable facies zones,local structures,faults and fractures,this paper studied the main factors controlling hydrocarbon accumulation in combinition with statistical analysis of the relationship between formation test data and sand thickness,reservoir property and logging data.The results show that favorable sedimentary microfacies zones,local structural setting,and faults & fractures are the three major factors controlling hydrocarbon accumulation.Hydrocarbon mainly accumulate in the underwater distributary channel sands of the delta front.The high of NW-SE-trending broad nose structure is the favorable place for hydrocarbon accumulation.The vertical and high-angle heterotropic fractures are the main effective factures in the study area.Faults and fractures control hydrocarbon accumulation.The discovered pools with a great amount of reserves are mainly distributed near the F2 and F3 fault zones with large fault displacement.The sandbodies of underwater distributary channel subfacies with well-developed faults and fractures in the local nose structures in the southeastern part of the study area are the the most favorable targets for further exploration.