Theoretical and technical innovations in strategic discovery of a giant gas field in Cambrian Longwangmiao Formation of central Sichuan paleo-uplift, Sichuan Basin

Abstract

Since 2011, huge gas fields have been discovered in the Sinian and Cambrian strata in Moxi–Gaoshiti region, central Sichuan paleo-uplift, with the geological reserves reaching more than one trillion cubic meters. The main gas-bearing layers include Deng 2 Member, Deng 4 Member and Longwangmiao Formation. Based on brief review of the exploration history of large gas province in central Sichuan paleohigh, the paper systematically describes the formation conditions and petroleum accumulation patterns of huge gas fields there, and points out the large ancient uplift background, huge net of hydrocarbon supply system, large-scale grain shoal reservoirs and regional reservoir-cap combinations are important material conditions for the formation of large gas fields. In view of the huge depth, high temperature, high pressure and some other complex formation conditions, a lot of efforts have been put into the research on logging, seismic, drilling, reservoir stimulation etc, and a series of accomplishments have been achieved, which work well in the exploration and development of gas in Sichuan Basin. The Sinian and Cambrian strata in the Sichuan Basin have a great potential for petroleum exploration. Key words: Longwangmiao Formation, paleohigh, giant field, strategic discovery, aulacogen, central Sichuan paleouplift