石油地质学论文石油地质勘探论文陕北地区长7沉积相特征及石油地质意义.docVIP

石油地质学论文(石油地质勘探论文）：陕北地区长7沉积相特征及石油地质意义 摘要:论文的目的：查明陕北地区延长组长7沉积环境及古地理演化，进而寻找有利砂体及石油聚集区。论文的方法：采用野外观察与室内研究相结合的方法对长7沉积相进行专项研究。结果研究区发育三角洲相和湖泊相，三角洲前缘及深湖浊积岩发育。在古地理演化过程中，长73湖盆达到鼎盛，浅湖区及深湖区分布范围均最大，沉积了广泛分布的张家滩油页岩;三角洲砂体不太发育，浊积岩零星分布;从长73—72—长71，湖岸线及深湖线均向湖内收缩，三角洲前缘砂体及浊积砂体逐渐发育。论文的结论：发育良好的油页岩为延长组主要的烃源岩，而三角洲及浊积岩砂体可以作为好的储层。 关键词:长7;延长组;沉积相;陕北地区;石油地质意义Sedimentary facies characteristic and petroleum geological significanceof Chang 7 in Shanbei AreaPANG Jun-gang Abstract:Aim To ascertain depositional system of Yanchang formation Chang 7 in Shanbei Area and furthermoreprobe favorable sand body and high-yield oil area.Methods Combined research methods of field exploration andindoor analysis are adopted，sedimentary facies of Chang 7 are studied as special item.Results Delta and lake fa-cies are recognized.Furthermore，the sub-facies and micro-facies are recognized，delta front and turbidite in deeplake are bothdeveloped well.During the paleo-geography evolution of Chang 7，lake basin is at its best duringChang 73，shallow lake and deep lake are both at its best，resulting to Zhangjiatan shale broadly distributed，deltasandstone developed not well and turbidite distributed scattered;From Chang 73，Chang 72to Chang 71，lakeshoreline and deep lake line are both moved toward lake center，but sandstones sedimented by delta front and turbiditegradually developed better.Conclusion The well developed oil shale can be as good hydrocarbon source rock andsandstones formed by delta front and turbidite can be good reservoir. Keywords:Chang 7;Yanchang formation;sedimentary facies;Shanbei Area;petroleum geological significance 研究区地处鄂尔多斯盆地陕北斜坡，该斜坡为微向西倾斜的单斜构造。盆地内构造相对简单，以鼻状构造为主，地层平缓，倾角一般不足1°。根据沉积序列，延长组可划分为5个岩性段:T3y1—T3 y5。同时，根据油层纵向分布规律自上而下又可划分为长1—长10油层组［1］。延长组经历了湖盆的产生、发展，演化及消亡的过程［2－3］。长7最大湖泛期沉积的暗色泥岩、油页岩为延长组的主要烃源岩。根据沉积旋回，长7自上而下为长71、长72、长73。随着石油的勘探开发，对三角洲发育的长2、长6储层研究较多，长7作为烃源岩的研究也较多。近年研究发现，长7深水区存在的浊积岩可以作为石油储层，打破了深水区为油气勘探禁区的观念。目前，对长7沉积相展布规律的研究基本明确［4］，而这些研究还不能满足进一步石油勘探的需要。本次拟在长7小层划分的基础上，研究其沉积相类型、各种沉积相的特征、展布规律及古地理演化，以