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

本研究以利比亚西部地中海Gabes-Tripoli盆地新生代断裂、褶皱和碳酸盐岩台地发育为研究对象。该研究区域包括许多对利比亚具有重要经济意义的大型油气油田（例如拥有100 - 30亿桶石油的Bouri油田）。然而，尽管该研究区域具有相关性和价值，但目前仍有一些未解决的问题，包括：(i) Gabes-Tripoli盆地晚白垩世至近期区域构造发育影响沉积模式和全盆地地层学；（ii）含烃背斜的构造发育与潜在三叠系盐基底的作用有关；（iii）碳酸盐岩台地发育；构造与沉积相互作用控制储层发育（沉积作用、成岩作用、构造覆印、圈闭完整性）。建议的工作重点是分析一个独特的最先进的三维地下数据集(~1800平方公里的三维地震反射数据；利比亚国家石油公司（NOC）为学术研究提供了13口工业井的钻孔地球物理信息，以检验以下（部分有争议的）研究假设：(1) Gabes-Tripoli盆地深层三叠系盐的存在是利比亚海上构造发育的关键控制因素，它决定了盐拆离之上的褶皱样式，并控制了原有盐构造之上的储层（始新世多源灰岩）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基底的影响。(3)主要含油气背斜的西东向与NW-SE主断裂倾向相倾斜；背斜顶部褶皱和碳酸盐岩台地的优先生长早于北西-东向断裂的发育。(4)主要储层灰岩内的成岩变化（如白云化作用、与下伏盐结构相关的埋藏腐蚀）可以通过三维地震反射数据识别，通过测井数据验证地震属性分析。(5)新近纪Gabes-Tripoli盆地的碳酸盐岩台地在构造、规模、类型和分布上与古近系有所不同。(6)沉积后构造和差异地层负荷影响储层发育。受新近至近代构造影响较大的地区缺乏地下储层。本研究计划的最后一个重要方面是在一个被学术文献很大程度上忽视的地区发展基本的构造和地层知识，由于政治原因，目前在该地区进行的研究很少。

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.