The Hydrocarbon Accumulation Mechanism and Exploration Prospects for the Dengying Formation of Sinian in Sichuan Basin
Wei Sun¹, Shugen Liu¹, Keyou Han², Guozhi Wang¹, Dan Li², Guoshen Xu¹,
Yuehao Ye¹, and Wei Zhang¹
¹National Key Laboratory of Oil and Gas Reservoir Geology and Exploitation, Chengdu, China
²Exploration&Production Research Institute of PetroChina Oil and Gasfield Company, Chengdu, China
The exploration for the Dengying Formation of Sinian in the Sichuan Basin has been nearly five decades, experienced four stages, Weiyuan gas field exploration stage, around Sichuan basin exploration stage, Leshan-Longnvshi paleo-uplift exploration stage and now Gaoshiti- Moxi structure belt exploration stage. In addition to the discovery of Weiyuan Gas Field was proved natural gas reserves of 408.61 × 108m3 , only Gaoshiti - Moxi gas-bearing structure has made a breakthrough. This paper summarizes the exploration results and material of the Sinian in Sichuan Basin and adjacent areas, and analyzes the conditions of the Sinian accumulation of hydrocarbon source, reservoir conditions and caprock conditions, combined with the characteristics of structural evolution and the accumulation process recovery, from a broader perspective to analyze the Dengying Formation of hydrocarbon accumulation in Sichuan Basin. On this basis, combining the impact of the Leshan-Longnvshi paleo-uplift formation and evolution on the oil and gas geological conditions, and according to comparative and analysis the Lower Paleozoic gas reservoir in Weiyuan-Ziyang area and Gaoshiti - Moxi similarities and differences, we think that Leshan-Longnvshi palaeo-lift had formed large-scale Palaeo oil reservoirs, Palaeo-oil reservoirs cracking form Palaeo-gas reservoirs. Himalayan movement transformed Sichuan Basin, and transformed the Palaeo gas reservoirs simultaneously. Weiyuan Gas Field is a short distance migration gas reservoir, and Gaoshiti - Moxi structure is formed gas reservoir by the Palaeo gas reservoir adjusted. Therefore, the gas generating center, the gas accumulating center and the gas preserving center did not change significantly area is still important areas of exploration Dengying Formation in the Leshan-Longnvshi paleo-uplift and adjust area.
AAPG Search and Discovery Article #90175©2013 AAPG Hedberg Conference, Beijing, China, April 21-24, 2013