济阳坳陷古近系页岩油地质特殊性及勘探实践——以沙河街组四段上亚段—沙河街组三段下亚段为例

基于前期基础研究与勘探实践，建立了济阳坳陷沙河街组四段上亚段—沙河街组三段下亚段页岩岩相发育模型，通过剖析济阳坳陷古近系泥页岩的储集性、含油性、可压性和页岩油的可动性及其协同演化特征，形成了针对性的勘探目标评价体系，支撑了济阳坳陷页岩油勘探的全面突破。明确指出了济阳坳陷页岩油6个方面的特殊性：①济阳坳陷古近系泥页岩岩相具有富含碳酸盐、纹层发育、大面积分布的特点；②无机孔隙和微裂缝形成的孔、缝网络体系是页岩油赋存的有利储集空间；③中、高演化程度富含碳酸盐纹层状页岩游离油富集；④有机、无机协同演化控制了泥页岩储集性和含油性的有效匹配；⑤异常高压体系有利于页岩油产出；⑥富含碳酸盐泥页岩具有中等可压性，通过组合缝网压裂工艺可实现有效改造。形成了基于泥页岩"四性"参数的陆相断陷盆地页岩油有利目标评价体系，建立了页岩油分级优选目标评价流程，破解了济阳坳陷页岩油地质—工程双甜点优选难题。中、高演化程度页岩油勘探的突破，特别是中等演化程度页岩油勘探的突破，大大拓展了济阳坳陷断陷湖盆页岩油勘探空间，也将丰富页岩油勘探理论。

Geological particularity and exploration practice of Paleogene shale oil in Jiyang depression: a case study of the upper submember of Member 4 to the lower submember of Member 3 of Shahejie Formation

Based on the previous basic research and exploration practice, this paper establishes the shale lithofacies development model of the upper submember of Member 4 of Shahejie Formation and the lower submember of Member 3 of Shahejie Formation in the Jiyang depression. By analyzing the reservoir property, oil-bearing and fracability of Paleogene mud shale in the Jiyang depression, as well as the mobility and co-evolution characteristics of shale oil, the specific exploration target evaluation system has been created to support the all-round breakthrough in shale oil exploration in the Jiyang depression. The particular characteristics of shale oil in the Jiyang depression is indicated in six aspects:(1) The Paleogene mud shale lithofacies in Jiyang depression are characterized by rich carbonates, development and large-area distribution of of laminae; (2) The pore-fracture network system formed by inorganic pores and micro-factures is a favorable reservoir space for the occurrence of shale oil; (3) Free oil is enriched in the carbonate-rich laminar shale with medium and high evolution stage; (4) The organic and inorganic co-evolution controls the effective matching of the reservoiring property and oiliness of mud shale; (5) Abnormal high pressure system is conducive to the production of shale oil; (6) Carbonate-rich mud shale has medium fracability, which can be effectively transformed using the combined fracture network technology. In conclusion, the paper creates the favorable target evaluation system of shale oil in the continental rift basin based on the four-property parameters of mud shale, establishes the target evaluation process of shale oil classification and optimization, and solves the problem regarding the optimizaiton of the geology and engineering sweet spots in Jiyang depression. The breakthrough in the exploration of shale oil with medium and high evolution stage, especially in the exploration of shale oil with medium evolution stage, has greatly expanded the exploration space of shale oil in the fault lacustrine basin in Jiyang depression and will also enrich the exploration theory of shale oil.