Diagenetic Simulation of Paleogene Clastic Reservoir Based on Diagenesis in Bozhong Depression, China

Abstract

The mid-deep clastic reservoir of Paleogene in Bozhong Depression has become the main task to petroleum exploration in Bohai, and thus, study on its diagenesis and heterogeneity and reason on reservoir properties evolution and development mechanism are of great significance to evaluation of hydrocarbon resources. Based on reservoir mineral features and diagenesis, sediment characteristics, diagenetic fields and diagenesis sequence in the basins is researched, and the evolution model of “Diagenetic Stage-Diagenetic Facies-Reservoir Property” of the clastic reservoir is constructed to simulate the reservoir evolution process in burial history. Reservoir properties, diagenesis environment as well as diagenetic facies indicate that there are six types of diagenetic facies in the mid-deep clastic reservoir, and three of them (feldspar debris dissolution facies, residual intergranular pore facies and carbonate dissolution facies) are favorable diagenetic facies belts. Diagenesis sequences vary with diagenetic facies, and “weak compaction-medium cementation-medium dissolution” and “weak compaction-weak cementation-strong dissolution” determine favorable reservoirs distribution. The concept of Diagenetic Process System Simulation is proposed for the first time, in which we discuss the spatiotemporal matching relationship among diagenetic material, diagenetic field, diagenetic stages, diagenetic facies, diagenesis, and reservoir physical properties. Its essence emphasizes the idea of dynamic quantitative research dominated by process recovery.