The Model of Sandbody Controlled by Dynamic Provenance System and its Exploration Significance in Superposition Area of Strike-Slip and Extension Stress in the South of Bohai Sea

Laizhouwan sag in Bohai Bay basin is a fault basin controlled by extensional fault depression and strike slip pull apart, which is an important oil and gas exploration area in Bohai Bay. Exploration practice shows that the prediction of high quality reservoir is the core problem of exploration in this area. Based on the analysis of drilling, seismic data and structural physical simulation in Laizhouwan depression, this paper analyzes the structural deformation under the stress field of strike slip extensional superposition, and points out the dynamic source controlled sand model in the strike slip extensional superposition area. Firstly, The structural response of "pressure relief settlement, pressure boosting uplift" under the mechanism of strike slip extension stress superposition stress is the root cause of block uplift drop alternation transformation. As a result, the southern slope zone of Laizhouwan depression shows the structural pattern of early uplift and late uplift in the East and early uplift and late uplift in the west, forming a "seesaw" structural evolution pattern. Secondly, the unique paleogeomorphology controls the orderly distribution of sedimentary system in time and space. In the Paleocene, the east uplifted, forming a local provenance system. In the denudation area above the slope break developed fracture weathering shell type reservoirs, and the subsidence area under the slope break developed fan delta deposits; In the early Eocene, the relatively flat platform palaeogeomorphology was developed, which created favorable conditions for the development of mixed sedimentary body of lacustrine carbonate and delta; At the end of Eocene, the West was pressurized and uplifted, the East was released and subsided, and the braided river delta sediments of Western provenance were developed. Under the guidance of this recognition, the hidden dynamic provenance was successfully identified in the study area.