Tectonics and carbonate platform development, Gabes-Tripoli Basin, offshore Libya

利比亚近海加贝斯-的黎波里盆地的构造和碳酸盐平台开发

• 批准号: 417476001
• 负责人: Privatdozent Dr. Stefan Back
• 金额: --
• 依托单位: Lehrstuhl für Geologie und Paläontologie (GIA)
• 依托单位国家: 德国
• 项目类别: Research Grants
• 财政年份: 2019
• 资助国家: 德国
• 起止时间: 2018-12-31 至 2022-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/417476001?language=en
• 关键词: Tectonics; carbonate; platform; development; Gabes

This research proposal targets the Cenozoic development of faults, folds and carbonate platforms in the Gabes-Tripoli Basin, Mediterranean Sea, western offshore Libya. The study area encompasses numerous large hydrocarbon fields (e.g. the Bouri Field with 1,000–3,000 Million barrels oil) that are of major economic importance for Libya. Yet, despite the relevance and value of the study area, there are today unsolved issues including (i) the late Cretaceous to recent regional tectonic development of the Gabes-Tripoli Basin influencing sedimentary patterns and the basinwide stratigraphy; (ii) the structural development of hydrocarbon bearing anticlines concerning the role of a potential Triassic salt substratum; (iii) carbonate platform development through time; and (iv) the interaction of tectonic and sedimentary processes controlling reservoir development (deposition, diagenesis, structural overprint, trap integrity).The proposed work focuses on the analysis of a unique state-of-the-art 3D subsurface dataset (~1800 km2 3D seismic-reflection data; borehole-geophysical information of 13 industrial wells) kindly provided for academic research by the National Oil Corporation of Libya (NOC) to test following (partly controversial) research hypotheses: (1) The presence of Triassic salt in the deeper subsurface of the Gabes-Tripoli Basin was a key control for structural development offshore Libya, determining fold style above a salt detachment and controlling the formation of reservoir rocks (Eocene nummulitic limestones) above pre-existing salt structures. (2) Faulting, folding, carbonate sedimentation and trap formation in the Gabes-Tripoli Basin was not influenced by the Triassic salt substratum. (3) The W-E orientation of major hydrocarbon-bearing anticlines is oblique to the main NW-SE fault trend; folding and the preferential growth of carbonate platforms at the top of anticlines pre-date the development of NW-SE-oriented faults. (4) Diagenetic changes (e.g. dolomitisation; burial corrosion in relation to underlying salt structures) within the main reservoir limestones can be identified on 3D seismic-reflection data by seismic-attribute analysis validated at well locations by wireline data. (5) Neogene carbonate platforms of the Gabes-Tripoli Basin differ in architecture, size, type and distribution from their Paleogene predecessors. (6) Post-depositional tectonics and differential stratigraphic loading influenced reservoir development. Areas significantly affected by Neogene to recent tectonics lack subsurface reservoirs.A final important aspect of this research proposal is the development of fundamental tectonic and stratigraphic knowledge in a region largely neglected by the academic literature, in which, for political reasons, little research can currently take place.

该研究计划针对利比亚西部近海地中海Gabes-Tripoli盆地新生代断层、褶皱和碳酸盐岩台地的发育。研究区域包括许多大型油气田（例如，拥有10亿至30亿桶石油的Bouri油田），这些油气田对利比亚具有重要的经济意义。然而，尽管研究区域的相关性和价值，今天仍有未解决的问题，包括：（i）影响沉积模式和盆地地层的加贝斯-的黎波里盆地的晚白垩世至近代区域构造发展;（ii）关于潜在三叠纪盐基底作用的含油气背斜的结构发展;（iii）碳酸盐台地随时间的发展;构造作用与沉积作用的相互作用对储层发育的控制作用（沉积、成岩作用、构造叠加、圈闭完整性）。拟议的工作重点是分析独特的最先进的三维地下数据集（~1 800平方公里的三维地震反射数据; 13口工业威尔斯井的钻孔地球物理资料），由利比亚国家石油公司（NOC）提供，用于学术研究，以测试以下内容：（部分有争议的）研究假设：（1）Gabes-Tripoli盆地深层地下三叠纪盐的存在是利比亚近海构造发展的关键控制因素，决定了盐拆离体上方的褶皱样式，并控制了先存盐构造上方储集岩（始新世钱币状石灰岩）的形成。(2)Gabes-Tripoli盆地的断裂、褶皱、碳酸盐沉积和圈闭形成不受三叠纪盐下层的影响。(3)主要含油气背斜的东西向与NW-SE向断裂主走向成斜向，褶皱作用和背斜顶部碳酸盐岩台地的优先发育先于NW-SE向断裂的发育。(4)主要储层石灰岩内的成岩变化（例如，风化作用;与下伏盐结构相关的埋藏腐蚀）可通过电缆数据在井位置验证的地震属性分析，在3D地震反射数据上识别。(5)Gabes-Tripoli盆地新近纪碳酸盐岩台地在结构、规模、类型和分布上与古近纪前辈不同。(6)沉积后构造和差异地层负荷影响储层发育。受新近纪至现代构造影响显著的地区缺乏地下遗迹。本研究建议的最后一个重要方面是在一个被学术文献严重忽视的地区发展基础构造和地层知识，由于政治原因，目前几乎没有研究。