Structural diagenesis and its petroleum geological significance
ZENG Lianbo, ZHU Rukai, GAO Zhiyong, GONG Lei, LIU Guoping
1 China University of Petroleum-Beijing, Beijing 102249, China 2 China Petroleum Exploration and Development Research Institute, CNPC, Beijing 100083, China 3 Northeast Petroleum University, Daqing 163318, China
The formation and evolution of sedimentary reservoirs is controlled by sedimentation, tectonism and diagenesis, of which sedimentation is the foundation, and tectonism and diagenesis are the keys. Based on the main geological factors controlling formation and evolution of sedimentary reservoirs, the concept of structural diagenesis and its implications are put forward in the paper. Then the application of structural diagenesis in quantitative evaluation of tight and low-permeability reservoirs and effectiveness of natural fractures is analyzed. Structural diagenesis is referred to structural and diagenetic interaction occurring in the process of change from loose sediments to the formation of consolidated sedimentary rocks. Structural diagenesis is the study of the relationships between structural deformation and physical and chemical changes to sediments, including both the influences of structural deformation mode and deformation intensity on diagenesis and fluid, and the influences of diagenesis and fluid on structural deformation in sedimentary reservoirs. Structural diagenesis controls the formation and evolution processes of sedimentary reservoirs and distribution of effective reservoirs in petroliferous basins. So the study of the structural diagenesis can provide an effective way for evaluation of reservoir quality, natural fractures and fracture effectiveness in tight and low-permeability reservoirs.
