恩平凹陷源外隆起区新近系油气成藏条件与定量评价

Accumulation conditions and quantitative evaluation of Neogene oil and gas in uplift zone outside source kitchen of Enping sag

源外隆起区是珠江口盆地恩平凹陷近年勘探的重点区带,其石油地质条件区别于近洼陷带。综合利用地震、测井、油藏等资料,对隆起区成藏特征和富集规律展开研究,并提出了定量评价方法。隆起区以侧向长距离运移成藏为特征,多次跨断层运移为特色;断裂对油气晚期成藏具有控制作用。富足的供烃单元是油气远源富集的物质基础和动力来源,圈闭与主汇聚脊的组合构成良好的空间输导格架,圈闭捕获能力和运聚强度的时空匹配是富集的关键因素。研究提出了油柱高度序列法和SGR图版法两种定量评价方法,分别评价了隆起区油气运聚强度和富集潜力,有效指导了隆起区的勘探且具有推广价值。

In recent years the uplift zone outside source kitchen is a key exploration area in Enping sag of Pearl River Mouth Basin,and its petroleum geological conditions are different from those around the sag zone.Based on the data of seismic,logging and reservoir,this paper studies the hydrocarbon accumulation characteristics and enrichment law in the uplift zone,and establishes a quantitative evaluation method.The uplift zone is characterized by long distance lateral migration and accumulation,and multiple cross-fault migration;the faults have the controlling effect on oil and gas accumulation in late stage.The adequate hydrocarbon source supply unit is the material basis and power source of far distance source oil and gas enrichment.The combination of trap and main accumulation ridge constitutes a good channeling space framework.The time and space match of trap capture ability and migration-accumulation capacity is the key factor for oil and gas enrichment.Two quantitative evaluation methods of oil column height sequence method and shale gouge ratio(SGR)image method are proposed in this study to evaluate the oil and gas migration-accumulation capacity and enrichment potential in the uplift zone respectively,which guide the oil and gas exploration effectively in the uplift zone and have the great value for application.