Characteristics of Paleogene compression-extension deformation and exploration significance in the Baiyun East area, Pearl River Mouth Basin

Abstract

The Baiyun East area is one of the two favorable reservoir-forming areas in the Baiyun Sag in the Pearl River Mouth Basin. At present, exploration is facing the stage of turning to the deep strata of the Paleogene. In recent years, drilling has found that the sandstone in the deep gentle slope zone becomes less abundant, which contradicts the development model of extensional half-graben reservoirs. Based on the comprehensive interpretation of deep reprocessing 3-D seismic data and drilling data, a full 3-D structural analysis of the Paleogene and subbasement detachment surface in the Baiyun East area is carried out. The basin evolution stages are reclassified according to the dynamic mechanism. The tectonic sequence has been modified from a passive rift cycle to three cycles of passive rift-active rift-passive rift.The tectonic episode is subdivided into six curtains from three stage cycles: fault episode-fault depression conversion episode-depression episode is subdivided into rift two subepisodes-fold two subepisodes-rift shrinking episode-drift episode, and the subdivision scheme better reflects the law of strata deformation.A new model of compression-extension deformation of the Paleogene basin has been established in the eastern Baiyun area. In the development process of the extensional structure, the new model coordinates the Paleogene structure-sedimentary response of the eastern Baiyun area. This model enriches the evolutionary model of the South China Sea Basin and provides support for the exploration of new deep areas in the Baiyun Sag.

Keywords

• compressional-extensional deformation
• detachment surface
• tectonic evolution
• baiyun sag
• pearl river mouth basin