Geometry, kinematics and dynamic characteristics of a compound transfer zone: the Dongying anticline, Bohai Bay Basin, eastern China

Abstract

Abstract:The Dongying anticline is an E-W striking complex fault-bounded block unit which located in the central Dongying Depression, Bohai Bay Basin. The anticline covers an area of approximately 12 km 2 . The overlying succession, which is mainly composed of Tertiary strata, is cut by normal faults with opposing dips. In terms of the general structure, the study area is located in a compound transfer zone with major bounding faults to the west (Ying 1 fault) and east (Ying -8 and -31 faults). Using three-dimensional seismic data, wireline log and checkshot data, the geometries and kinematics of faults in the transfer zone were studied, and fault displacements were calculated. The results show that when activity on the Ying 1 fault diminished, displacement was transferred to the Ying -8, Ying -31 and secondary faults so that total displacement increased. Dynamic analysis shows that the stress fields in the transfer zone were complex: the northern portion was a left-lateral extensional shear zone, and the southern portion was a right-lateral extensional shear zone. A model of potential hydrocarbon traps in the Dongying transfer zone was constructed based on the above data combined with the observed reservoir rock distribution and the sealing characteristics of the faults. The hydrocarbons were mainly expulsed from Minfeng Sag during deposition pe- riods of Neogene Guantao and Minghuazhen Formations, and migrated along major faults from source kitchens to reservoirs. The secondary faults acted as barriers, resulting in the formation of fault-bound compartments. The high points of the anticline and well-sealed traps near secondary faults are potential targets. This paper provides a reservoir formation model of the low-order transfer zone and can be applied to the hydrocarbon exploration in transfer zones, especially the complex fault block oilfields in eastern China.

Hydrothermal Dolomite Paleokarst Reservoir Development in Wolonghe Gasfield, Sichuan Basin, Revealed by Seismic Characterization

“…3D seismic dataset: The seismic dataset set covers an area of approximately 160 km 2 , and was used to understand the nature and morphology of underground rock layers in the Wolonghe area of the Sichuan Basin [25]. The seismic dataset used in this study is from the Pre-Stack Time Migration (PSTM) seismic common reflection poin (CRP) gather collected from 2014 seismic acquisition and processing in the Wolonghe area.…”