泌阳凹陷北部斜坡复杂断块群油气成藏主控因素

Main Controlling Factors of Hydrocarbon Accumulation of Complex Fault-block Group in the North Slope of Biyang Depression

泌阳凹陷北部斜坡的烃源岩主要是下第三系核桃园组三段的暗色泥岩砂泥岩,有机碳平均含量为1.77%,干酪根为Ⅰ型和Ⅱ1型;储层以下第三系核三段细砂岩为主,孔隙度一般20%～35%,渗透率(150～900)×10-3μm2;油藏类型以断块油藏、断鼻油藏和断层-岩性复合油气藏为主。北部斜坡油气成藏主要受构造演化、断裂发育、沉积相和温压场流体势控制,构造演化和流体势控制油气的运聚方向,断裂和砂体的展布控制油气运聚模式和富集程度。

In the north slope of Biyang Depression,hydrocarbon source rocks were predominantly dark shale and sandy shale in the 3rd member of Paleogene Hetaoyuan Formation,with the TOC average content of 1.77% and kerogens of typeⅠand Ⅱ1;Reservoir rocks were mainly composed of sandstone and fine sandstone in the 3rd member of Paleogene Hetaoyuan Fm,with the porosity of 20～35% and permeability of 150～900×10-3μm2;The types of oil pools were mainly composed of fault-block,fault-nose and composite oil pools of fault plus lithology.The north slope hydrocarbon accumulation process is controlled dominantly by structural evolution,rupture growth,sedimentary facies,temperature-pressure field and fluid potential.Structural evolution and fluid potential control the direction of migration and accumulation of oil and gas;the distribution of rupture and sand controls the mode of migration and accumulation of oil and gas and enrichment extent.