Paleogene geological framework and tectonic evolution of the central anticlinal zone in Lufeng 13 sag, Pearl River Mouth Basin

Abstract

The Paleogene geological framework and evolution process in the central anticline zone in the Lufeng 13 sag in Pearl River Mouth Basin is well analyzed through seismic data and drilling data, and control of tectonic evolution on hydrocarbon accumulation is also discussed. The results show that the central anticline zone in the Lufeng 13 sag develops the upper deformation layer and lower deformation layer. The “arched graben system” is developed in the upper deformation layer, and the magmatic diapir structure and flowing deformation of plastic strata is developed in the lower deformation layer. The evolution process of the central anticline zone can be divided into four stages, i.e. fault block uplifting stage, prototype stage, strengthening stage and finalization stage. The geological framework and tectonic evolution of the central anticline zone control Paleogene hydrocarbon accumulation. The Paleogene two-layer geological framework is favorable for development of structural traps and composite traps; the paleostructure highs are the direction of hydrocarbon migration, and the gravitational gliding faults are the main carrier bed for vertical hydrocarbon migration; the tectonic uplift is a key factor for reservoir diagenesis improvement and preservation of primary pores, and also controls distribution of high-quality reservoirs.