Research Status and Development Trends of Fault Seal in Petroleum Geology

Fault sealing and opening properties are crucial to hydrocarbon migration and accumulation. Fault sealing and opening properties refer to the displacement pressure difference caused by the lithological and physical property differences between the hanging wall and footwall of a fault, and this pressure difference controls the fluid flow capacity between the two sides of the fault. In terms of migration direction, fault sealing and opening properties are divided into vertical sealing and opening and lateral sealing and opening; in terms of the nature of the isolation zone, they are divided into fault plane sealing and opening and lithologic sealing and opening. The controlling factors of sealing and opening properties include juxtaposition, cataclasis, cementation, smear and filling, as well as asphaltene precipitation. The research methods for this property include the Allan plot method, fault plane pressure method, shale smear method and fuzzy mathematics method. At present, all the research methods are quantitative or semi-quantitative analyses with a single means from a certain perspective. Therefore, the breakthrough direction of research methods for fault sealing and opening properties will be comprehensive quantitative analysis from different perspectives.