Abstract An integrated study using gravity, 2D seismic, well logs, and geological data in the eastern Sirt Basin is presented in this research focussing on the Lower Cretaceous Sarir Sandstone which is the most important oil reservoir in the study area. Interpretation of basement architecture shows individual blocks are named in the present paper A, B and C, whilst depocentre represents the most pronounced topographic low within the study area and named D-Graben in this paper. The observed onset of rifting phase in the study area took place in the Early Cretaceous and was divided into three active and inactive phases contemporaneous with deposition of the continental clastic Sarir Sandstone. The basin-wide NW-SE syndepositional fault segments played consequently a significant role in the evolution of the irregular paleotopography, sediment infill and the created accommodation space resulting in controlling sedimentary thickness and facies distributions of the Sarir Sandstone. Some faults were reactivated during the Late Cretaceous-Palaeocene with no abrupt changes in stratigraphic thickness in the post Early Cretaceous section, which suggests non-tectonic post-rift (sagging) phase. The Sarir Sandstone reservoir unconformably overlies the basement (pre-rift sequence), and is therefore unconformably overlain by post-rift marine shales and carbonates of Late Cretaceous. The detailed analyses of log signatures variations, constrained by some core and cuttings information revealed that the deposition of Sarir Sandstone resulted essentially from alterative episodes of braided and meandering fluvial rivers. As a result, the Sarir Sandstone has been divided in general into lower and upper units, separated by a Red Shale bed. In turn the lower Sarir unit has been subdivided into two layers, whilst the Upper Sarir unit, which represents the main reservoir in the study area, has been subdivided into nine layers.

中文翻译：

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利比亚东部苏尔特盆地早白垩世 Sarir 砂岩储层的盆地结构和构造控制

摘要 本研究以该研究区最重要的油藏下白垩统 Sarir 砂岩为重点，利用重力、二维地震、测井和地质资料在苏尔特盆地东部进行了综合研究。对地下室建筑的解释表明，本文中的单个街区被命名为 A、B 和 C，而 depocentre 代表了研究区域内最明显的地形低，并在本文中命名为 D-Graben。研究区观察到的裂谷相开始于早白垩世，与陆相碎屑沙里尔砂岩沉积同时期分为三个活动期和非活动期。因此，盆地范围内的 NW-SE 同沉积断层段在不规则古地貌的演化中发挥了重要作用，沉积物填充和创造的容纳空间导致控制 Sarir 砂岩的沉积厚度和相分布。一些断层在晚白垩世-古新世重新活动，早白垩世后剖面的地层厚度没有突然变化，这表明非构造后裂谷（下垂）阶段。Sarir 砂岩储层不整合地覆盖在基底上（裂谷前层序），因此不整合地被裂陷后海相页岩和晚白垩世的碳酸盐岩覆盖。对受一些岩心和岩屑信息约束的测井特征变化的详细分析表明，Sarir 砂岩的沉积主要是由辫状河和蜿蜒河流的交替事件引起的。因此，Sarir 砂岩大体上分为下部和上部单元，由红色页岩层隔开。反过来，下部 Sarir 单元被细分为两层，而代表研究区主要水库的上部 Sarir 单元已细分为九层。