Shale diagenesis controls the generation, migration and accumulation of hydrocarbons through time and has become a frontier area of study in the fields of sedimentology and petroleum geology. There have been only a few studies on the generation of organic pores in lacustrine shale oil reservoirs during the oil generation thermal evolution stage. In this study, lacustrine organic-rich shale samples at various stages of maturity, from the first member of the Songliao Basin Qingshankou Formation were investigated, and a thermal transformation law of macerals was established, based on organic petrology. The diagenetic alteration styles and sequences were investigated using a high-resolution field emission scanning electron microscope, and cathode luminescence. Furthermore, automated pore extraction technology enabled the examination of the characteristics and genetic process of organic and inorganic pores under the influence of thermal maturation. The results indicate that a small quantity of pre-oil bitumen is generated during the early oil mature stage (R_o: 0.7% - 0.9%), and that the generation of a large quantity of post-oil bitumen that occurs following the peak oil generation stage (i.e., late oil mature stage, R_o: 1.1% - 1.4%), is controlled by the unimodal distribution of the activation energy of Type I kerogen. Compaction intensity certainly influences pore volume reduction. Siliceous cementation primarily occurs during peak oil generation maturity and the subsequent thermal evolution stage. The pores formed in the oil generation window primarily arise from mineral dissolution and organic matter polycondensation. Following peak oil generation, the pores undergo iron dolomitization, smectite illitization, and bitumen cracking. The degree of development of inorganic pores, the most common pore type in shale oil reservoirs, appears to have a significant impact on the total porosity of a reservoir shale. During thermal evolution, the inorganic pore volumes show a decreasing trend. There is a secondary pore development stage, reached when R_o exceeds 1.2%, closely related to the transformation of clay minerals. According to the hydrocarbon generation kinetics and compaction model, organic pore volumes increase gradually at 0.7%R_o, reach their peak at 1.1%R_o, and then steadily decrease due to compaction. The organic pores are relatively well developed when R_o is >0.85% (at the start of the oil window). The shale oil reservoir's most favorable thermal evolution stage is late oil maturity stage that follows the oil generation peak.

页岩成岩作用通过时间控制油气的生成、运移和成藏，已成为沉积学和石油地质学领域研究的前沿领域。关于生油热演化阶段湖相页岩油藏有机质孔隙生成的研究较少。本研究对松辽盆地青山口组一段不同成熟阶段的湖泊富有机质页岩样品进行了研究，并基于有机质岩石学建立了微质体的热转化规律。使用高分辨率场发射扫描电子显微镜和阴极发光研究了成岩改变的样式和序列。此外，自动孔隙提取技术能够在热成熟的影响下检查有机和无机孔隙的特征和成因过程。结果表明，在早期油成熟阶段（R_o : 0.7% - 0.9%), 以及在产油高峰期(即晚油成熟期, R _o: 1.1% - 1.4%)，受 I 型干酪根活化能的单峰分布控制。压实强度肯定会影响孔隙体积的减少。硅质胶结主要发生在产油成熟期和随后的热演化阶段。生油窗形成的孔隙主要来源于矿物溶解和有机质缩聚作用。在产油高峰之后，孔隙经历铁白云石化、蒙脱石伊利石化和沥青裂解。无机孔隙是页岩油储层中最常见的孔隙类型，其发育程度似乎对储层页岩的总孔隙度具有显着影响。在热演化过程中，无机孔体积呈减小趋势。有一个次生孔发育阶段，当 R_o超过1.2%，与粘土矿物的转化密切相关。根据生烃动力学和压实模型，有机质孔隙体积在 0.7%R o 时逐渐增加，在 1.1%R _o时达到峰值，然后由于压实作用逐渐减小。_{当R o} >0.85%时（油窗开始时），有机质孔隙相对发育。页岩油藏最有利的热演化阶段是生油高峰之后的晚油成熟阶段。