Journal of African Earth Sciences ( IF 2.2 ) Pub Date : 2023-12-25 , DOI: 10.1016/j.jafrearsci.2023.105152 Khaled Albriki , Wei Guoqi , Feiyu Wang , Rajab El Zaroug , Abdulati Abdullah
The lower Silurian hot shale in the Ghadames Basin was investigated to provide a regional assessment of the future prospects of shale gas play as an important unconventional resource system in one of the top African superglobal petroliferous sedimentary basins. The unconventional natural gas potential of the hot shale was studied based on regional improved organofacies assessment, thermal maturity, the timing of generation and expulsion, and sweet gas spot analysis, such as gas in place (GIP), total expelled gas (TEG), and total retained gas (TRG). The integration between regional geology and organic geochemistry, together with the proper regional utilization of the multi-dimensional basin modeling to better appreciate the importance of the Silurian hot shale as a key future shale gas unconventional-rich petroleum system (URPS) in the Ghadames Basin. The relationship between the richness and thermal parameters, such as the total organic carbon indicator (%TOC), hydrogen index (HI), measured and time step (calibrated models) vitrinite and equivalent vitrinite (%VRo) reflectance were used to develop quality control models for the regional natural gas spots of the Silurian hot shale were present-day mapping presentations are utilized as well for each parameter to better appreciate the lateral variability of the dry gas volumes. Regional basin control parameters from several key wells, such as heat flow levels, formation pressure system, and basin porosity were successfully utilized for the hot shale gas play resource screening (sweet spots) study utilizing multi-dimensional modeling approaches. The established regional spatial type B marine organofacies of the hot shale with excellent geochemical properties (∼18 %TOC) and regionally sufficient thermal maturation (∼2.45 %VRo, post-mature stage) indicate a significant amount of natural gas expelled and retained that has occurred in the Silurian hot shale system. The estimated GIP of the hot shale is about 120 bcf/km2 (equivalent to 320 bcf/section). The maximum expelled gas (TEG) amount is defined with values up to 88 bcf/section and the total estimated volume of the retained gas (TRG) is up to 96 bcf/km2, with the current geological architecture, geochemical properties, volumes, and distribution of the hot shale dry gas sweet spot in the Ghadames Basin. The hot shale can be considered in the near future for extensive further studies and exploration and development plans in Libya, Algeria, or Tunisia.
中文翻译:
北非加达梅斯盆地志留纪热页岩的页岩气成藏:综合地球化学和盆地建模的见解
对 Ghadames 盆地的下志留统热页岩进行了调查,以对页岩气作为非洲顶级含油沉积盆地之一的重要非常规资源系统的未来前景进行区域评估。基于区域改进的有机相评价、热成熟度、生排时序以及天然气地质储量(GIP)、总排汽量(TEG)等低硫气点分析,研究了热页岩的非常规天然气潜力。和总保留气体(TRG)。区域地质学和有机地球化学的整合,以及多维盆地模型的适当区域利用,以更好地认识志留系热页岩作为Ghadames盆地未来关键的页岩气非常规富油气系统(URPS)的重要性。丰富度和热参数之间的关系,如总有机碳指标 (%TOC)、氢指数 (HI)、测量和时间步长(校准模型)镜质体和等效镜质体 (%VRo) 反射率用于制定质量控制志留纪热页岩区域天然气点模型也采用了当今的测绘演示,每个参数也都使用了这些模型,以更好地了解干气量的横向变化。几个关键井的区域盆地控制参数,如热流水平、地层压力系统和盆地孔隙度,已成功利用多维建模方法用于热页岩气区资源筛选(甜点)研究。已建立的热页岩区域空间B型海相有机相具有优良的地球化学性质(~18%TOC)和区域充分的热成熟度(~2.45%VRo,后成熟阶段),表明大量天然气被排出和滞留,发生在志留系热页岩系统中。热页岩的 GIP 估计约为 120 bcf/km 2(相当于 320 bcf/剖面)。根据当前地质结构、地球化学性质、体积,最大排出气体 (TEG) 量定义为高达 88 bcf/section,保留气体 (TRG) 的总估计体积高达 96 bcf/km 2。Ghadames盆地热页岩干气甜点区及分布. 在不久的将来,可以考虑在利比亚、阿尔及利亚或突尼斯对热页岩进行广泛的进一步研究以及勘探和开发计划。