坪北探区延长组长8、 长9油层组资源潜力分析

以大量的岩心和测井资料为基础，利用铸体薄片、扫描电镜及压汞等测试分析方法，对坪北探区延长组长8和长9油层组的沉积环境、储层特征以及生储盖的组合关系进行了研究，结果表明长9期属浅湖相沉积，沉积物普遍较细，其顶部发育一套优质烃源岩，厚度5～14ITI，具有良好的供烃能力；长8期位于安塞三角洲沉积前缘，主要发育三角洲前缘水下分流河道和河口坝砂体，具有良好的储集空间，以原生残余粒间孔隙为主；区域内发育自生自储式、下生上储式、上生下储式3种成藏组合类型．根据坪北探区延长组长8、长9层试油成果，综合评价认为：坪北探区自生自储式成藏组合类型和下生上储式成藏组合类型具有良好的勘探前景，可通过实施滚动勘探进一步扩大含油面积，作为下一步开发的接替资源．

PREDICATION OF THE ORE RESOURCE POTENTIAL OF CHANG 8 AND CHANG 9 OIL GROUP OF YANCHANG FORMATION IN PINGBEI EXPLORATION AREA

In recent years,along with the exploration change of Yanchang formation in strategy,Pingbei exploration area achieved new discovery in Chang 8 and Chang 9 oil group of Yanchang formation.Based on the massive core data,with SEM observations microscopic-analysis,casting thin sections and conventional Hg injection techniques,the results showed Chang 9 oil group is shallow lake deposition and sediments are fine.Chang 8 oil group locates in Ansai delta front,underwater distributary channel and debouch bar sandbodies whose storage space are big developed.Reservoir space is made up of original residual pore between grains.There is one set of premium hydrocarbon source rock on the top of Chang 9 oil group,about 5~14 m thick,which generate hydrocarbons strongly.There are three types of reservoir assemblage in this area,self-generation and self-accumulation ones,lowe generation and high accumulation ones,high generation and low accumulation ones.According to oil-test results of Chang 8 and Chang 9 oil group,self-generation and self-accumulation ones,low generation and high accumulation ones in Pingbei exploration area present good oil exploration prospect.Oil-bearing area can be increased by progressive exploration,it′s also the replacement resources of next exploitation.