Progress on the Features of Laminated Physical Property and Hydrocarbon Accumulation of Lacustrine Fine-grained Sedimentary Rock

Key words: 
• varve /
• fine-grained deposition rock /
• physical property /
• hydrocarbon enrichment /
• shale reservoir

Abstract: [Objective] Statistics of published literature and analysis of previous research results show that the reservoir physical properties and oil and gas enrichment of laminar fine-grained sedimentary rocks are obviously superior to those of undeveloped/weakly developed laminar fine-grained sedimentary rocks and have a very good positive correlation with them. Compared with the laminar structure of Marine fine-grained sedimentary rocks, the laminar lacustrine fine-grained sedimentary rocks are limited by the sedimentary environment being closer to the provenance area, the frequent change of sedimentary environment hydrodynamics, and the more obvious control by climate and tectonic activities. As a result, the reservoir physical properties and oil and gas enrichment characteristics of different types of laminar rocks are not the same. The summary of relevant differences is still unclear and needs to be revealed.[Method] By focusing on the relevant literature at home and abroad in the past ten years, the types and causes of pores and fractures of lamellar fine-grained sedimentary rocks are reviewed, and the controlling effects of lamellar composition, continuity and sequence combination on reservoir physical properties and hydrocarbon enrichment characteristics are described respectively. [Results] It is believed that the laminar structure has the advantages of frequent turnover of vertical material composition, abnormal development of internal micro-fractures and different evolution of organic matter under the laminar structure, which further improves the ability of oil and gas enrichment on the basis of fine-grained sedimentary rocks. . [Prospects] It is pointed out that there is still a lack of difference and comparison of reservoir physical properties of fine grained sedimentary rocks which are all laminated due to different factors such as pores and fractures in each other's layers, and it will be the development direction in the future to use computer to invert macro reservoir sedimentary model based on micro laminar data to guide unconventional reservoir development