Xingkai taphrogenesis and petroleum exploration from Upper Sinian to Cambrian Strata in Sichuan Basin,China

TLDR: Based on the theory of the Xingkai taphrogenesis, the present paper analyzes the evolutionary process of the Mianyang-Lezhi-LongchangChangning intracratonic sag and its control on the Upper Sinian to Cambrian petroleum geological conditions as discussed by the authors.

Abstract: The present paper approaches the effects of the Xingkai taphrogenesis on the Upper Sinian to Cambrian oil and gas accumulation in Sichuan Basin.Based on the theory of the Xingkai taphrogenesis,the present paper analyzes the evolutionary process of the Mianyang-Lezhi-LongchangChangning intracratonic sag and its control on the Upper Sinian to Cambrian petroleum geological conditions.The evolutionary process of the intracratonic sag can be divided into the pregnant stage of extension(uplifting and eroding)at the end of the Late Sinian Dengying period,the beginning stage of extension at the Early Cambrian Maidiping period,the summit stage of extension at the Early Cambrian Qiongzhusi period,the decreasing stage of extension at the Early Cambrian Canglangpu period,and the dispersal stage of extension at the Early Cambrian Longwangmiao period.The process has controlled the superior source rock development of the Lower Cambrian Qiongzhusi Formation,the superior reservoir development and preservation of the Upper Sinian and Lower Cambrian strata,and the formation of the petroleum conduit system.There are probably groups of the Upper Sinian and Lower Cambrian large natural gas fields(including shale gas)within and surrounding the Mianyang-Lezhi-Longchang-Changning intracratonic sag in Sichuan Basin.