Compared with marine facies shale strata, lacustrine shale strata are more complicated in geological conditions, and thus more difficult to explore and develop. To realize economic exploration and development of lacustrine shale oil, the geological regularities of accumulation and high yield of retained movable petroleum in shale should be understood first. In this work, taking the shale strata of Kong 2 Member and Sha 3 Member in the Paleogene of Huanghua depression in the Bohai Bay Basin as examples, based on the previous joint analysis results of over ten thousand core samples and the latest oil testing, production test and geochemical data of more than 30 horizontal wells, accumulation conditions and models of retained movable petroleum in lacustrine shale were studied comprehensively. The study shows that at moderate organic matter abundance (with TOC from 2% to 4%), shale strata have the best match between oil content and brittleness, and thus are rich in oil and good in fracability. Moderate ancient lake basin size and moderate sediment supply intensity are the internal factors leading to best coupling of organic matter abundance and brittle mineral content in the shale formation. Moderate thermal evolution maturity of R_o of 0.7%–1.0% (at burial depth of 3200 to 4300 m) is the interval where oil generation from thermal evolution and oil adsorption by kerogen in shale layers match best, and retained movable petroleum is high in proportion. Moderate diagenetic evolution stage (3200 to 4300 m in the middle diagenetic stage A) is conducive to the formation of a large number of dissolved pores and organic matter pores, which provide storage space for shale oil enrichment. Moderate development degree of natural fractures (without damaging the shale oil roof and floor sealing conditions) is conducive to the storage, seepage and preservation of shale oil. The research results have overthrown the general understanding that high organic matter abundance, high maturity, and high development degree of natural fractures are conducive to shale oil enrichment, and have guided the comprehensive evaluation of shale oil and gas sweet spots and well deployment in the second member of the Kongdian Formation in the Cangdong sag and the Shahejie Formation in the Qikou sag. Industrial development of the shale oil in Kong 2 Member of the Cangdong sag has made major breakthrough, and important signs of shale oil have been found in Sha 3 Member of the Qikou sag, demonstrating huge exploration potential of lacustrine shale oil.

与海相页岩地层相比，湖相页岩地层的地质条件较为复杂，因此勘探和开发难度更大。为了实现湖相页岩油的经济开发，首先要了解页岩的成藏规律和高残留率。本文以渤海湾盆地黄hua陷古近系孔2段和沙3段页岩地层为例，以以往对上万个岩心样品的联合分析结果和最新的试油，生产为依据。全面研究了湖相页岩中30多个水平井的测试和地球化学数据，沉积条件和保留的活动石油模型。研究表明，在中等有机质丰度下（TOC为2％至4％），页岩地层在含油量和脆性之间具有最佳匹配，因此富含油且易碎。适度的古湖流域规模和适度的沉积物供应强度是导致页岩地层中有机质丰度和脆性矿物含量最佳耦合的内部因素。R的中等热演化成熟度_Ø0.7％–1.0％的深度（在3200至4300 m的埋藏深度）是页岩层中由热演化和干酪根吸附油而产生的油最匹配且保留的可移动石油所占比例最高的时间间隔。适度的成岩演化阶段（中成岩阶段A 3200〜4300 m）有利于大量溶孔和有机质孔的形成，为页岩油的富集提供了储存空间。天然裂缝的适度发展程度（不破坏页岩油顶板和底板的封闭条件）有利于页岩油的储藏，渗漏和保存。研究结果推翻了普遍的认识，即有机质含量高，成熟度高，天然裂缝发育程度高有利于页岩油的富集，并指导了苍东凹陷的孔店组第二段和祁口凹陷的沙河街组页岩油气甜点点和井位的综合评价。苍东凹陷的孔二段页岩油的工业发展取得了重大突破，齐口凹陷的砂三段页岩油已经发现了重要标志，表明湖相页岩油具有巨大的勘探潜力。