天然气工业2026，Vol.46Issue(7)：35-47,13.DOI:10.3787/j.issn.1000-0976.2026.07.004
四川盆地中南部筇竹寺组页岩储层压力形成机制及其地质意义
Pressure formation mechanism in the Qiongzhusi Formation shale reservoirs of the central-southern Sichuan Basin and its geological significance
摘要
Abstract
Overpressure is widely observed in the shale of the Lower Cambrian Qiongzhusi Formation in the central-southern Sichuan Basin,and significant pressure differences exist among different types of shale reservoirs.However,the formation mechanisms and controlling factors of shale overpressure remain poorly understood.Based on well-log data of the Qiongzhusi shale reservoirs in the central-southern Sichuan Basin,this paper systematically investigates the genesis,evolutionary process and controlling factors of overpressure across different shale lithologies by means of multiple overpressure identification methods including combined logging method,porosity comparison method,and acoustic velocity-density crossplot method.The following results are obtained.First,two types of overpressure systems are identified in the study area.Specifically,the overpressure in the organic-rich shale is mainly caused by hydrocarbon generation,while that in the silty shale is jointly controlled by fluid charging and differential compaction.Second,the dominant timing of overpressure development varies with overpressure types.Hydrocarbon generation overpressure mainly occurs during the oil window and crude oil cracking stages,whereas fluid charging overpressure is closely related to fault activity during critical tectonic episodes and to pore preservation.Differences in pressurization timing and main controlling factors are the principal reasons for pressure differentiation among different types of shale reservoirs.Third,the evolution of overpressure is directly responsive to the natural gas charging process.The'pressure-resistant pore preservation'effect of overpressure reservoirs results in better preservation conditions and higher gas content.In conclusion,two overpressure development models are established,and the pressure coefficient is determined to be a key indicator for selecting sweet spots of Qiongzhusi shale gas.The research findings provide guidance for the sweet spot prediction and well placement in the shale gas development in the Sichuan Basin.关键词
四川盆地中南部/筇竹寺组/储层压力/超压成因/生烃增压/差异压实/甜点Key words
Central-southern Sichuan Basin/Qiongzhusi Fm/Pressure of strata/Overpressure genesis/Hydrocarbon generation overpressure/Differential compaction/Sweet spot分类
能源科技引用本文复制引用
杨洪志,张洞君,李博,杨学锋,朱宁,谢圣阳,赵圣贤,齐亚东,陈凤,张德良..四川盆地中南部筇竹寺组页岩储层压力形成机制及其地质意义[J].天然气工业,2026,46(7):35-47,13.基金项目
国家科技重大专项项目"四川盆地深层页岩气效益开发技术与集成示范"(编号:2025ZD1405300)、中国石油青年科技专项项目"寒武系筇竹寺组超深层页岩气地质工程甜点评价及立体开发模式研究"(编号:2024DQ03067). （编号:2025ZD1405300）
