Hydrocarbon origin and reservoir forming model research of Longwangmiao Formation, Moxi-Gaoshiti area, Sichuan Basin

• Published in: Petroleum Vol. 2; no. 2; pp. 130 - 137
• Main Authors: Jin, Mindong, Cao, Jian, Shi, Chuanhua, Zeng, Wei, Shen, Cheng, Shi, Kailan, Cheng, Xueying, Tan, Xiucheng
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01.06.2016; KeAi Communications Co., Ltd
• Subjects: Accumulation evolution; Bitumen; Gas reservoir; Longwangmiao formation; Moxi-Gaoshiti area; Sichuan basin; Accumulation evolution; Sichuan basin; Gas reservoir; Moxi-Gaoshiti area; Longwangmiao formation; Bitumen
• ISSN: 2405-6561
• DOI: 10.1016/j.petlm.2016.04.003

This paper focuses on the Longwangmiao gas reservoir in Moxi-Gaoshiti area, Sichuan Basin. Starting from the tectonic evolution perspective, though comparing biological marker compound and analyzing fluid inclusions, the oil & gas origin and accumulation evolution of Longwangmiao Formation are systematic studied with reference to the burial-thermal evolution of single well geological history in the study area. It is suggested that the oil & gas reservoir is generally characterized by early accumulation, multi-stage filling, late cracking and later adjustment. The oil and gas were mainly sourced from lower Cambrian Qiongzhusi Formation, partly from the Permian source rock. During the geological period, 3 major oil & gas fillings occurred in the Longwangmiao Formation, namely Caledonian-Hercynian filling that was small in scale and produced the first phase of paleo-oil reservoir that soon destroyed by Caledonian movement uplift, large-scale Permian filling that gave rise to the second-phase of paleo-oil reservoir and the Triassic-Jurassic filling that enriched the second phase of paleo-oil reservoir. Finally, the paleo-oil reservoir experienced an in-situ cracking during the cretaceous period that gave rise to a natural gas reservoir and left behind carbonaceous bitumen and oily bitumen in the holes of the Longwangmiao Formation.