3D geological modeling of the 428 Tectonic Zone in Bozhong Depression using GOCAD software

The 428 tectonic zone is a buried hill, located in the central part of Bozhong Depression in Bohai Bay basin, and is the result of multi-stage fold superposition and extensional fracture. How to understand the three-dimensional geometric features of the buried hill is very important to reveal the superposition-remodeling process in different tectonic stages and the development of deep oil and gas reservoirs. In this paper, a 3D geological model of the 428 tectonic zone was constructed based on 3D seismic and drilling data using 3D geological modeling software GOCAD. By comparing and analyzing the stratigraphic distribution and fault development in the model, we identified the fold deformation pattern of the 428 tectonic zone and its peripheral area, as well as the intersection of inner faults in the 428 tectonic zone. The eastern 428 tectonic zone is a uni-structural belt where the Paleozoic strata overlay the Archean basement, while the western 428 tectonic zone is a dual- structural belt where the Paleozoic and Mesozoic strata sit on the Archean basement. The fold deformation patterns of the two belts reflect the superposition of Indosinian and Yanshanian folding processes.