【作者】 薛军民；

【导师】 柳益群；

【作者基本信息】 西北大学 ， 油气田地质与开发， 2009， 博士

【摘要】 以陕北地区蟠龙油田三叠系延长组为研究对象,运用沉积学、石油地质学等理论,综合应用大量的钻井、测井及各种分析化验资料,采取理论与实际研究相结合,宏观与微观研究相结合的方法,系统分析了蟠龙油田延长组地层与构造、沉积与储层及成藏规律的研究,总结了该探区的油气分布规律,取得的主要成果和认识,概括为以下几方面：(1)研究区三叠系延长组精细的构造编图和分析研究表明,蟠龙探区三叠系延长组各油层顶面并非是简单的单斜构造,而是在西倾单斜背景上发育一系列鼻状隆起构造,其规模和分布位置在各油层组既有继承性又有差异性,长2油层顶面构造与长4+5、长6顶面构造相比,鼻状隆起更发育。(2)通过岩性、沉积构造、粒度、古生物及测井相的分析,认为长6时期研究区主要为三角洲前缘沉积,其中长64～长62时期为三角洲前缘亚相沉积,长61时期为三角洲平原亚相沉积,分流河道为主要的储集类型;长4+5沉积时期继承了长6’沉积时期面貌,前期主要为三角洲平原分流河道沉积,后期形成漫滩沼泽化沉积；长2时期主要为辫状河流相沉积,河道砂坝为主要的储集微相类型；长1时期为三角洲平原沉积,局部地区为浅湖沉积。(3)烃源岩评价表明,长1暗色泥岩主要为Ⅰ型有机质,长2、长6主要为Ⅲ型有机质,长4+5中Ⅱ型和Ⅲ型均占一定比例,长7主要为Ⅱ型。长7有机质丰度最高,其次为部分长4+5和长1暗色泥岩,其余层位丰度差,因此对成油贡献不大。油源对比证实各目的层(长2、长4+5及长6)油源主要来自于长7湖相的“张家滩”页岩,部分来自于长1、长4+5和长6暗色泥岩。(4)成岩作用研究表明,本区砂岩储集层发生的成岩作用主要为压实作用、胶结作用、交代作用和溶蚀作用,同时,认为早成岩期的压实作用及胶结作用是低孔、低渗储层形成的主要原因。(5)根据研究区岩心、普通薄片、铸体薄片及扫描电镜等的观察结果,并结合大量孔、渗透资料,得出本区成岩相类型有绿泥石胶结相、自生碳酸盐胶结相、碳酸盐溶蚀相、长石溶蚀相、浊沸石胶结相及浊沸石溶蚀相。进一步分析认为,各种溶蚀孔隙相和绿泥石膜残余孔隙相往往代表着较好的储层。(6)长6、长2内流体运移、聚集特征表明,在各地质历史时期,流体运聚距离较短、流体聚集区较多,且有较好继承性。特别对于长6油藏,古流体运聚特征对其成藏有明显控制作用,这是长6油层往往在构造低部位能成藏的原因(其他成藏条件具备的情况下)。(7)油气富集规律表明：长2油藏纵向上主要分布于长21、长22两个油层亚组中,平面上主要分布在研究区的北部和中部地区,主要受控于沉积相、鼻状隆起构造、运移通道和盖层等四个因素。长6油藏平面上主要分布在南部的沙则沟地区,纵向上富集在长61亚组,次为长62、长63亚组中,主要受油源条件、有利沉积相及储层条件、盖层条件、运移通道等四大因素控制。更多还原

【Abstract】 With the theory of sedimentlogy and petroleum geology, by a large number of drilling, logging and various analytical data applied, taking the means of theoretical study and practical research to combine and the combination of theoretical study and practical research, research on stratum and tectonic、reservoir sedimentation and accumulation rules were taken; oil and gas distribution and accumulation model in exploration area were summarized inYanchang formation Of Triassic, in Panlong field,Ordos Basin, the Results and cognition were gain generally as follows:Research on fine structure mapping of Triassic in the study area showed that reservoir inYanchang formation of Triassic, in Panlong field is not the simple monoclinic structure but a series of tectonic uplift noses developed on mnocline dumped to west whose scale and location not only have inheritance but also differences succeed. For instance, compared with top surface structure in the oil layer Chang 4+5andchang6, the nose-shaped bulge in in the oil layer Chang 2 were developed so much.By means of analysis of lithology、sedimentary structures grain size、paleontology and logging, the sedimentary facies in the oil layer Chang 6 was mainly delta front deposition, among which the delta front subfacies deposition developed at from Chang64to Chang62 and delta plain subfacies deposition developed at Chang 61; reservoir types were mainly sandstone deposited in distributary channel; sedimentation face was succeed when the stratum of Chang 4+5 deposited, the sedimentation type was delta plain distributary channel deposition previous and back swamp deposit; the sedimentation type at Chang 2 was braided fluvial deposition and the reservoir microfacies types is channel sand dam? the sedimentation type at changl was delta plain sediments, shallow lake sediment developed in some areas.The evaluation on hydrocarbon source rocks showed that type of organic matter of dark mudstones from changl formation mainly belongs to,chang2 and chang 6 mainlyⅢrespectively,the type Hand III take some proportion in chang4+5,chang 7mainlyⅡ; organic matter abundance in chang 7 is highest,second is chang 4+5 and chang l,the rest is worse;ecept the mudstone in chang 7 come to maturity,the rest also immaturtity,which have little contribution to reservoir.Simultaneously,oil-source correlation confirmed the oil source all come from the Zhang-jiapan lacustrine shale in chang7,partlt from dark mudstone in chang1、chang4+5andchang6 formation.Diagenesis studies have shown that the diagenesis type of sandstone reservoir mainly compaction, cementation, metasomatism and dissolution; at the same time, diagenetic compaction and cementation in early period main reason which led to low porosity and low permeability reservoir.Reservoir enrichment rules demonstrated that the oil layer chang2 distributed in sub-formationchang21andchang22 longitudinally and horizontally distributed in the northern and middle part of the study zone,which was controlled by sedimentary facies、nose like structure、migration pathway and capping formation; the oil layer chang6 horizontally distributed in the Saze duct areas and enriched longitudinally insub-formation of chang6, secondary is sub-formationchang62andchang63 which was controlled by petroleum sources、favorable sedimentary facies、reservoir conditions、migration pathway and capping formation.更多还原