【作者】 杨华；

【导师】 陈洪德；

【作者基本信息】 成都理工大学 ， 古生物学与地层学， 2004， 博士

【摘要】 本论文以鄂尔多斯盆地三叠系延长组为研究对象,运用沉积学、石油地质学、地球物理学等理论,以大量的野外剖面、钻井和地震资料为基础,理论研究与实际研究相结合,宏观研究与微观研究相结合的技术思路,系统研究了鄂尔多斯盆地的沉积体系特征、主力油层的沉积微相、砂体形态及其展布、储层特征。明确提出了盆地延长组主要发育东北、西南两大沉积体系,盆地东北部以曲流河三角洲沉积体系为主,而西南部辫状河三角洲沉积体系较发育的特点;并认为砂体展布受沉积体系控制,西南部沉积体系砂体从环县至正宁,砂体形态主要呈东西向、北东向条带状展布,东北部沉积体系砂体连片性好,以朵状为主;通过沉积演化研究认为延长组是在盆地坳陷持续发展和稳定沉降过程中堆积的以河流—湖泊相为特征的陆源碎屑岩系,在湖盆发育到长7期达到鼎盛,之后逐渐萎缩;结合勘探成果重点论述了各期不同三角洲的发育特征,岩性及物性特征,并对各三角洲的含油性进行了分析和对比,明确了沉积环境是影响储层储集性能的地质基础的认识;通过典型油藏解剖分析认为三角洲砂体与区域西倾大单斜构成最佳配置,砂体上倾方向为洼地沼泽或分流间湾泥质沉积,有利于油气的富集与保存,辫状河三角洲、扇三角洲前缘砂体和三角洲前方的浊积体为油气聚集的有利场所,提出了不同类型的三角洲沉积体系的成藏模式。同时,依据沉积体系、砂体预测研究成果,结合成藏规律,分小层评价出有利勘探目标,为鄂尔多斯盆地中生界石油勘探指明了方向。更多还原

【Abstract】 This paper investigates the Yanchang formation in Triassic system of Ordos basin, using theories as sedimentology, petroleum geology, geophysics, et al., based on abundant outcrop sections, well drilling and seismic data. This paper also systemly investigates the characteristics of deposition systems in Ordos basin, sedimentary microfacies of the leading pay formations, sand bodies and its distributions, and reservoir characteristics, adopting the technique methods of academic research combined with practice research and macroexaminations combined with microexaminations. From the analysis of paleocurrent data, light minerals data and heavy minerals data of Ordos basin’s fringe , we conclude that main deposition systems developed in Yanchang Formation include northeast and southwest deposition system. The distributions of the sand bodies are controlled by deposition system. Southeast deposition system’s sand bodies’ configuration that have low component and textural maturity presents a band shape of east-west and northeast-southwest trend from Huanxian to Zhengning. Northeast deposition system’s sand bodies which have a good continuity presents a northeast-southwest trend in the plane .Having an overview on the evolvement from member 10 to member 1 of Yanchang formation, Ordos lacustrine facies basin expanded gradually and then shrinked. The siliciclastic Yanchang formation which characterized by fluvial-lacustrine facies was cumulated in the period of continuant sagging and stable subsiding of Ordos basin. Ordos lacustrine facies basin expanded to its height at member 7 stage, Then, the basin came to shrinking as the continuant infilling of fluvial. This paper discusses the developoment characteristic, lithology and properities of different delta of different stage, and analyses and contrasts the oilness of different delta.Delta sandstone and the regional big westleaning monocline make of a best combination. Bottomland, swamp and bight depositions above the sand bodies make for the accumulation and preservation of oil and gas. Turbidites at the frontpage of braid river delta sand bodies and fan delta front sand bodies are favorable reserviors for oil and gas accumulating. Accumulating patterns of different delta deposition system are put forward. Based on the deposition systems and sand bodies forcasting combined with accumulating rules, potential areas can be identified.更多还原