Research progress and prospects of the stages, genesis and fluid evolution of micro-fracture veins in petroliferous basins

Abstract

Faults and fractures in sedimentary rocks are important channels for fluid activities in petroliferous basins.Different stages and types of mineral veins filled in fractures are the product of hydrocarbon-water-rock interactions, recording the formation process of faults and fractures fluid properties, components, sources, temperature and pressure fields, redox environment and other information in different stages of the process. They provide important clues to study the development of faults in sedimentary basins, the characteristics of fluid dynamic fields, physical and chemical environments.This paper systematically summarizes the basic methods of fluid activity tracing and evolution of fracture veins in petroliferous basins and their current geological applications, and believes that they are mainly concentrated in three aspects: First, through the petrological observation of diagenetic minerals filled with fracture veins, to analyze the type, structure and relative order of formation of diagenetic minerals; the second is to trace the nature, source, temperature and pressure of vein-forming paleo-fluids through geochemical tests such as isotopes, trace rare earth elements, and fluid inclusions of vein diagenetic minerals- redox environment, etc.; the third is to accurately determine the formation time of veins by testing radioisotopes of diagenetic minerals in veins(such as U-Pb, Re-Os, etc.), and discuss vein formation processes and hydrodynamic fields based on regional structural evolution environment and its dynamic evolution process.Finally, the problems of existing research methods are analyzed, and the future development trends and geological application prospects are discussed, in order to provide references for the study of the evolution of paleofluid in petroliferous basins and their relationship with hydrocarbon migration and accumulation and preservation.

Keywords

• rare earth elements
• paleofluid evolution
• diagenetic sequence
• fracture vein
• petroliferous basin