断陷盆地缓坡区控砂控藏机制与勘探发现——以歧口凹陷歧北缓坡带为例

发布时间：2018-01-20 14:32

本文关键词： 层序地层坡折带缓坡带地层-岩性油气藏断陷湖盆歧口凹陷油气勘探　出处：《石油学报》2017年07期 　论文类型：期刊论文

【摘要】：为揭示断陷盆地缓坡区的控砂控藏机制,以高品质的800km~2三维地震和91口钻井资料为基础,层序地层和沉积演化分析表明,受控于断块掀斜和差异沉降作用,歧口凹陷歧北斜坡南侧在古近纪表现为具挠曲坡折的缓坡带。该带层序界面标志清晰,包括削截、顶超和上超等反射终止类型,由此将古近系划分为3个二级层序和11个三级层序。三级层序的结构样式类似于具陆架坡折的被动大陆边缘,其低位体系域和湖扩体系域普遍发育不同类型的岩性圈闭。其中,沙河街组三段—沙河街组二段沉积期,研究区断陷作用强烈,挠曲坡折带的坡度较大,层序的低位体系域主要发育大型低位扇;随后,拗陷作用增强,挠曲坡折带的坡度逐渐减小,至东营组沉积期转变为以低位三角洲沉积为主。湖扩体系域的岩性圈闭发育在沙河街组二段—沙河街组一段和东营组,发育湖相碳酸盐岩滩坝和碎屑岩滩坝。研究区挠曲坡折带明显控制了地层-岩性圈闭的发育和分布,成为缓坡带油气勘探的有利场所。通过勘探实践,新增三级储量近4×10~8t,探井成功率达80%,展示了挠曲缓坡带地层-岩性油气藏良好的勘探前景。
[Abstract]:In order to reveal the mechanism of sand control and reservoir control in the gentle slope area of faulted basin, the analysis of sequence stratigraphy and sedimentary evolution shows that the reservoir control mechanism is based on the high quality 800km-2 3D earthquake and 91 drilling wells. Controlled by fault block tilting and differential subsidence, the south side of Qibei slope in Qikou sag shows a gentle slope belt with flexural slope break in Paleogene. The sequence interface of this zone is clear, including cutting. The Paleogene is divided into three secondary sequences and 11 third-order sequences. The structure of the third-order sequence is similar to that of the passive continental margin with continental shelf slope break. Different types of lithologic traps are generally developed in its lowstand system tracts and lacustrine extension system tracts. Among them, during the depositional period from the third member of Shahejie formation to the second stage of Shahejie formation, the study area has strong fault subsidence, and the slope of the flexural slope break zone is large. Large low-stand fans are mainly developed in the low system tracts of sequence. Subsequently, the depression increased and the slope of the flexural slope gradually decreased. The lithologic traps of the lacustrine extension system tract developed in the second member of Shahejie formation and the first member of Shahejie formation and Dongying formation. The development of lacustrine carbonate beach dam and clastic rock beach dam. The flexure slope break zone in the study area obviously controls the development and distribution of stratigraphic and lithologic traps and becomes a favorable place for oil and gas exploration in the gentle slope zone. The new third-grade reserves are nearly 4 脳 10 ~ (-1) t, and the success rate of exploration is 80%, which shows a good prospect for exploration of stratigraphic-lithologic reservoirs in the flexural gentle slope zone.
【作者单位】：中国石油大港油田公司;中国地质大学资源学院;中国石油大学地球科学与技术学院;
【基金】：中国石油天然气股份有限公司重大科技专项“大港油区大油气田勘探开发关键技术研究”(2014E-06-01)资助
【分类号】：P618.13
【正文快照】： (1.PetroChina Dagang Oilfield Company,Tianjin300280,China;2.Faculty of Earth Resources,China University of Geosciences,Hubei Wuhan 430074,China;3.School of Geosciences,China University of Petroleum,Shandong Qingdao 266580,China)引用:赵贤正,蒲秀刚,王家豪,

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