下扬子苏皖南地区上二叠统页岩油气地质条件研究

下扬子地区广泛发育厚度大、有机质含量高的上二叠统海陆过渡相泥页岩,但是勘查程度低,缺乏对页岩油气地质条件的系统分析。下扬子苏皖南地区上二叠统大隆组和龙潭组泥页岩埋藏深度适中,部署的多口探井获得了良好的油气显示。结合前人资料,通过野外调查、岩心观察、测试分析和资料对比等手段,对苏皖南地区上二叠统泥页岩进行了页岩油气成藏条件与保存条件的综合分析。研究表明,苏皖南地区上二叠统地层具有良好的生烃基础和储集条件,但有机质成熟度变化大,构造活动复杂,导致了区内不同地区油气保存和富集条件的差异。建议在重点地区开展页岩油气保存条件和埋藏演化史的精细研究,以寻求突破,力争带动整个下扬子地区的勘探开发进程。

Study on geological conditions of Upper Permian shale oil and gas in Lower Yangtze area of southern Jiangsu-Anhui Province

The Upper Permian marine-continental transitional shale developed extensively in Lower Yangtze area, with great thickness and rich organic matter content, but the exploration degree of this area is low and it lacks systematic analysis on shale oil and gas geological conditions. The burial depth of the shale in Dalong and Longtan Formations in southern Jiangsu-Anhui area is favorable, and the exploration wells deployed previously have obtained good oil and gas display. Based on previous data, the authors comprehensively analyzed the accumulation and preservation conditions of shale oil and gas in the Upper Permian shale in southern Jiangsu-Anhui Province by means of field investigation, core observation, test analysis and data comparison. The results show that the Upper Permian strata in this area have good hydrocarbon generation and reservoir conditions, and the differences in thermal evolution maturity are related to tectonic evolution, reflecting the differences in oil and gas preservation and enrichment conditions. Based on previous studies, we suggested that fine research on shale oil and gas preservation conditions and burial evolution history should be carried out in key areas to seek exploration breakthrough and to improve the exploration and development of shale oil and gas in the entire Lower Yangtze region.