松辽盆地榆树断陷火石岭—营城组油气地质特征研究

发布时间：2018-03-18 08:04

  本文选题：松辽盆地　切入点：榆树断陷　出处：《吉林大学》2017年硕士论文　论文类型：学位论文

【摘要】：随着近年松辽盆地东部断陷带的深层勘探取得突破,断陷盆地展现了广阔的勘探前景。榆树断陷位于松辽盆地东南隆起区,是东部断陷带内的一个复合半地堑盆地,由榆东、榆西两个次级断陷组成,勘探面积2741km2。断陷层主要由火石岭组、沙河子组与营城组构成。通过对区内地震资料的闭合解释,建立了研究区的地层构造格架,结果显示榆东、榆西两个次级断陷均为雁行式组合断裂控制的半地堑式断陷复合体,二者被中部榆树凸起分隔,并以榆树凸起为中线,总体形成了镜像的次级断陷组合;火石岭组地层受控盆断裂影响较小,广泛分布于断陷及榆树凸起区域内,沙河子组及营城组地层受控盆断裂控制,主要分布于断陷内部。以研究区内6口探井岩心相分析为基础,结合单井相综合分析,建立了火石岭组、沙河子组和营城组的岩相模式。研究区内共识别出六种岩相,分别是湖泊相、三角洲相、扇三角洲相、湖底扇相、近岸水下扇相和火山岩相,划分出12种沉积亚相、21种沉积微相;使用地震相识别方法,建立了区内岩相与地震相对应关系,恢复了火石岭组-营城组的岩相展布。其中火石岭组主要发育湖泊—扇三角洲沉积体系,同时形成了较大规模的火山爆发相、溢流相;沙河子组主要发育半深湖—扇三角洲—近岸水下扇沉积体系;营城组内发育滨浅湖—扇三角洲—近岸水下扇沉积体系,局部发育少量火山溢流相。岩心测试数据结果统计显示,火石岭组及沙河子组的暗色泥岩为榆树断陷的主要烃源岩,地化指标显示其有机质丰度高,干酪根类型以Ⅱ2型为主,处于成熟的演化阶段。碎屑岩是区内重要储集单元,其物性以特低孔、特低渗为特征,且广泛分布火石岭组及营城组的火山岩可以提供潜在的储集空间。榆树断陷内发育自生自储、上生下储及下生上储型生储盖组合。油气地质条件综合分析表明,研究区有利勘探区带主要位于榆东次断陷的中部次凸区,其内火山穹窿构造带与厚层优质半深湖相烃源岩侧向接触,是油气勘探的有利目标。
[Abstract]:With the breakthrough of deep exploration in the eastern Songliao basin in recent years, the faulted basin presents a broad prospect of exploration. Yushu fault depression is located in the southeast uplift area of Songliao basin, and is a composite semi-graben basin in the eastern fault depression zone. The exploration area is 2741 km2. The fault subsidence is mainly composed of Huoshiling formation, Shahezi formation and Yingcheng formation. Through the close interpretation of seismic data in the area, the stratigraphic structural framework of the study area has been established. The two secondary faults of Yuxi are semi-graben type fault depression complex controlled by echelon type combination fault. They are separated by the middle Yushu uplift, and take the Yushu uplift as the middle line, forming the mirrored secondary fault depression assemblage as a whole. The formation controlled basin fault of Huosiling formation has little influence and is widely distributed in the fault depression and Yushu uplift area, and the controlled basin fault is controlled by Shahezi formation and Yingcheng formation. Based on the core facies analysis of 6 exploration wells in the study area and the comprehensive analysis of single well facies, the lithofacies models of Huosiling formation, Shahezi formation and Yingcheng formation are established. Six kinds of lithofacies are identified in the study area. They are lacustrine facies, delta facies, fan delta facies, sublacustrine fan facies, nearshore underwater fan facies and volcanic facies. Twelve sedimentary subfacies and 21 sedimentary microfacies are divided, and the corresponding relationship between lithofacies and seismic facies in the area is established by using seismic facies identification method. The lithofacies distribution of Huosiling and Yingcheng formation was restored. The Huoshiling formation mainly developed lacustrine fan delta sedimentary system and formed a large scale volcanic eruption facies and overflow facies. In Shahezi formation, there are mainly semi-deep lacustrine-fan deltaic and near-shore underwater fan sedimentary systems, while in Yingcheng formation, shore-shallow lacustry-fan delta-inshore subaqueous fan depositional system is developed, and a few volcanic overflow facies are developed locally. The dark mudstone of Huosiling formation and Shahezi formation is the main source rock of Yushu fault depression. The geochemical index shows that its organic matter abundance is high, the kerogen type is mainly type 鈪，

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