摘要
在综合沉积相、油源对比、地层压力结构、包裹体均一温度等方面的基础上,对鄂尔多斯盆地吴起-定边地区延长组下部油气成藏模式与主控因素进行了研究,认为研究区发育长7和长9两套烃源岩,油源对比显示吴定地区长8、长9油气主要来源于长7烃源岩,长9烃源岩次之;延长组长7生烃增压是石油向下运移的主要动力,平面上长7及长8过剩压力差低值背景下的高值区是油气聚集的主要场所;延长组下部以三角洲前缘水下分流河道和河口坝为主,能够形成孔渗条件较好的储集空间;且长8、长9油藏具有"幕式充注、连续成藏"的特征,两者同属于源下成藏组合;综合分析认为上三叠统油藏分布主要受"近源、低压、优相"三大因素的控制。
Based on the integrated studies of the sedimentary facies,oil-source correlation,formation pressure structure and homogenization temperatures of fluid inclusions,this paper researches the hydrocarbon accumulation models and the main controlling factors for the lower member of Upper Triassic Yanchang Formation in the Wuqi-Dingbian area of the Ordos Basin.The result shows that the formations Chang 7 and Chang 9 are the two sets of fine source rocks which possess good hydrocarbon generation potential in the region.Oil-source correlation shows hydrocarbon in the Chang 7 and Chang 9 formations mainly derives from the source rock Chang 7 in the Wuqi-Dingbian area,and the Chang 9 formation follows.Hydrocarbon generating pressurization is the main drive force for petroleum migration in the Chang 7 formation of the region.The area with high values in the background of low values in excess pressure difference for Chang 7 and Chang 8 is the main locus for hydrocarbon accumulation in the lower member of the Yanchang formation.The main sedimentary facies of the Yanchang formation in the research region is deltaic front subaqueous distributary channels and debouch bars;which may serve as reservoir space with generally higher porosity and permeability.The Chang 8 and Chang 9 reservoirs are characterized by episodic injection and continuous accumulation,and both of the reservoirs belong to hydrocarbon accumulation assemblages under source rocks.Comprehensive analysis suggests that the distribution of the upper Jurassic reservoirs is mainly controlled by three major factors of near sources,low pressure and good facies.
出处
《地质与勘探》
CAS
CSCD
北大核心
2012年第4期858-864,共7页
Geology and Exploration
基金
"十一五"国家科技支撑项目(项目编号:2007BAB17B00)
关键词
鄂尔多斯盆地
吴定地区
延长组
成藏规律
主控因素
Ordos Basin； Wuqi-Dingbian area； Yanchang Formation； forming rule； controlling factors
