Tectonic-sedimentary characteristics and exploration plays in the western section of Deyang-Wusheng Intracratonic Sag, Sichuan Basin

Abstract

The tectonic-sedimentary characteristics and exploration plays in the western section of the Deyang-Wusheng Intracratonic Sag in the Sichuan Basin were studied by combining geophysical and surface geological data and exploration results. The Deyang-Wusheng Intracratonic Sag is a northwest trending tectonic unit formed in the Changxing period of the Late Paleozoic under a weak extension stress background. It has a trough-like structure, and is thick on both sides and thin in the middle. High energy facies such as biological reefs and bioclastic beaches are developed at the edges (platform margins) on both sides, which is conducive to reservoir development. Lithological combinations of microcrystalline limestone, siliceous mudstone, carbonaceous mudstone and shale developed under deep water in the center of the trough are favorable source rocks. A strip-shaped biological reef developed along the northwest platform margin in the Longbaoliang 3D work zone in the western section of the Deyang-Wusheng Intracratonic Sag. Combined with underlying source rocks such as the Longtan Formation, it forms "lower source and upper reservoir" and "side by side" source-reservoir combinations. The marginal facies of the intracratonic sag is a potential exploration area, and the Longbaoliang area is a favorable target for exploration.

Keywords

• biological reef
• sedimentary characteristics
• source-reservoir combination
• changxing period
• late permian
• deyang-wusheng intracratonic sag
• sichuan basin