Tectonic–Hydrocarbon Accumulation of Laoyemiao Region in the Nanpu Sag, Bohai Bay Basin

Abstract: This paper aims to gain insight into Laoyemiao (LYM) tectonic features and utilizes the tectonic–hydrocarbon accumulation model by integrated analysis tectonic controls on suitable reservoirs, trap styles, and hydrocarbon migration. On the basis of 3‐D seismic data interpretation and the Xi'nanzhuang (XNZ) Fault geometry analysis, it has been assessed that the LYM tectonics is essentially a transverse anticline produced by flexure of the XNZ Fault surface and superimposed by Neocene north‐east‐trending strike‐slip faults. Transverse anticline is found to exert controls both on major sediment transportation pathways and sedimentary facies distribution. Fan‐delta plains that accumulated on the anticline crest near the XNZ Fault scrap and fan‐delta front on the anticline front and the upper part of both limbs slumps on synclines and the Linque subsag. In combination with the reservoir properties, suitable reservoirs are predicted in the subfacies of subaqueous distributary channel and mouth bar deposited on the anticline crest. The LYM‐faulted anticline accounts for the following trap groups: faulted‐block and anticline‐dominated trap, fault‐dominated traps, and combined and stratigraphic traps. Evidence from biomarkers of crude oil and hydrocarbon‐filling period simultaneous, or a little later to the strike‐slip fault activity, reveal that the strike‐slip faults penetrating into the deep source rock, by connecting with shallow reservoirs, provide the major hydrocarbon migration pathways.