陆相致密油形成地质条件及富集主控因素——以鄂尔多斯盆地三叠系延长组7段为例

发布时间：2018-07-22 10:05

【摘要】：鄂尔多斯盆地三叠系延长组7段为典型陆相致密油大油区。以大量岩心分析及室内模拟实验为基础,结合盆地致密油勘探开发实际,研究长7段形成致密油大油区的地质条件和主要控制因素。研究表明,长7段致密油具有分布范围广、烃源岩条件优越、砂岩储集层致密、孔喉结构复杂、物性差、含油饱和度高、原油性质好、油藏压力系数低的特点。长7沉积期西南陡、东北缓的湖盆底形和活跃构造条件有利烃源岩及储集岩沉积与分布;广覆式分布的优质烃源岩为致密油大油区的形成提供充足油源;大规模沉积砂体为致密油大油区的形成提供储集条件;发育的构造裂缝是形成致密油的有利运移通道;盆地稳定的沉积及构造演化为致密油区提供良好保存条件。长7段致密油富集的主控因素:1有效源储配置和持续充注是致密油形成的关键因素;2密集发育的微小孔隙是致密油富集的前提;3持续强大的石油充注控制致密油富集高产。
[Abstract]:Member 7 of the Triassic Yanchang formation in Ordos Basin is a typical continental dense oil area. Based on a large number of core analysis and laboratory simulation experiments combined with the exploration and development of dense oil in the basin the geological conditions and main controlling factors for the formation of dense oil in Chang7 formation area are studied. The results show that the tight oil of Chang 7 has the characteristics of wide distribution, superior source rock conditions, tight sandstone reservoir, complex pore throat structure, poor physical properties, high oil saturation, good crude oil properties and low reservoir pressure coefficient. The lacustrine basin bottom and active tectonic conditions of Chang7 sedimentary period are favorable to the deposition and distribution of source rocks and reservoir rocks, and the high quality source rocks with wide overlying distribution provide sufficient oil source for the formation of dense oil and large oil areas. Large-scale sedimentary sandbodies provide reservoir conditions for the formation of dense oil-rich areas; developed structural fractures are favorable migration channels for the formation of dense oil; stable deposits and tectonic evolution of basins provide good preservation conditions for dense oil areas. The main controlling factors of tight oil enrichment in Chang 7 formation are effective source allocation and continuous filling. The key factor for the formation of dense oil is the dense micropores, which are the premise of dense oil enrichment. The continuous and powerful oil filling controls the high concentration and high yield of dense oil.
【作者单位】：中国石油长庆油田公司;低渗透油气田勘探开发国家工程实验室;中国石油长庆油田公司勘探开发研究院;
【基金】：国家自然科学基金重大项目(41390451) 国家重点基础研究发展计划(973)项目(2014CB239003) “十三五”国家油气重大专项(2016ZX05046)
【分类号】：P618.13

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