摘要
近期,四川盆地川中古隆起北斜坡蓬莱地区震旦系灯影组天然气勘探取得重大发现,明确该地区油气成藏过程与流体压力演化对于正确认识该区气藏的形成和分布规律具有重要意义。为此,通过灯影组二段(以下简称灯二段)岩心与薄片观察、流体包裹体测温、激光拉曼光谱分析、PVT模拟等测试手段,明确了该地区灯影组成岩演化序列,重建了气藏压力演化历史与成藏演化过程。研究结果表明:①蓬莱地区灯二段经历了泥晶白云石→早期隐晶质石英→纤状白云石→纹层白云石→细晶白云石→早期沥青→中粗晶白云石→鞍状白云石→原油裂解+硫酸盐热化学还原作用+沥青→铅锌矿化作用→晚期石英→萤石→构造裂缝共13个成岩—成藏演化序列;②蓬莱地区灯二段经历了多期成藏演化过程,其中志留纪末期形成的第一期古油藏在海西早期发生破坏,三叠纪中—晚期是第二次原油规模成藏期,侏罗纪—早白垩世古油藏裂解形成古气藏,晚白垩世—现今是古气藏调整改造与保存期;③震旦系气藏经历了常压→弱超压→强超压→极强超压→强超压→弱超压→常压的演化过程,震旦系古超压是深埋高温与热液作用并叠加硫酸盐热化学还原作用使得古油藏完全裂解生气所造成。结论认为,蓬莱地区气藏保存至今主要与晚侏罗世至晚白垩世经历了持续超压有关,喜马拉雅期的构造抬升促使天然气扩散运移和调整,原始超压气藏逐步演化为现今的常压气藏。
Recently,major discoveries have been made in natural gas exploration in the Sinian Dengying Formation on the northern slope of the Central Sichuan Palaeohigh in the Sichuan Basin.Clarifying the hydrocarbon accumulation process and fluid pressure evolution in the Penglai area is of great significance in effectively understanding the formation and distribution of gas reservoirs in this area.Through core and thin section observations,temperature measurement of fluid inclusions,laser Raman spectroscopy,and PVT simulation of samples from the second member of Dengying Formation(Deng 2 Member),the diagenetic sequence of Dengying Formation in the Penglai area is clarified,and the pressure evolution history and hydrocarbon accumulation evolution process of gas reservoirs are reconstructed.The results show that the Deng 2 Member in the Penglai area has experienced 13 diagenetic–hydrocarbon accumulation evolution stages,including micritic dolomite,early quartz,fibrous dolomite,laminar dolomite,fine-grained dolomite,early bitumen,medium–coarse-grained dolomite,saddle dolomite,crude oil cracking+thermochemical sulfate reduction of sulfate+bitumen,lead–zinc mineralization,quartz,fluorite,and structure fractures.Deng 2 Member in the Penglai area has experienced a process of multistage hydrocarbon accumulation evolution.The first-stage ancient oil reservoir formed at the end of Silurian was destroyed in the early Hercynian.The middle–late Triassic is the second large-scale oil accumulation period.In the Jurassic–Early Cretaceous,the ancient oil reservoir cracked to form an ancient gas reservoir.The Late Cretaceous–present is the period of reformation,adjustment and preservation of the ancient gas reservoirs.The Sinian gas reservoirs have evolved in a process of normal pressure→weak overpressure→strong overpressure→extremely strong overpressure→strong overpressure→normal pressure.The ancient overpressure of the Sinian is a result of complete cracking of ancient oil reservoirs to generate gas owing to the hig
作者
范俊佳
姜华
鲁雪松
刘强
柳少波
马行陟
黄士鹏
曾富英
田华
谢武仁
FAN Junjia;JIANG Hua;LU Xuesong;LIU Qiang;LIU Shaobo;MA Xingzhi;HUANG Shipeng;ZENG Fuying;TIAN Hua;XIE Wuren(PetroChina Research Institute of Petroleum Exploration&Development,Beijing 100083,China;State Kay Laboratory of EnhancedOil Recovery,Beijing 100083,China)
出处
《天然气工业》
EI
CAS
CSCD
北大核心
2022年第12期32-43,共12页
Natural Gas Industry
基金
国家自然科学基金项目“多层盖层扩散效应及其对深层气藏封闭性影响机制”(编号:42002177)
中国石油天然气股份有限公司科学研究与技术开发项目“油气地质基础新理论新技术研究”(编号:2021DJ01)
“海相碳酸盐岩成藏理论与勘探技术研究”(编号:2021DJ05)
中国石油勘探开发研究院国际合作项目“流体包裹体微区分析与深层—超深层油气成藏演化”(编号:YGJ-2019-04-03)。
关键词
四川盆地
蓬莱地区
震旦系
灯影组
白云岩
流体包裹体
PVT模拟
压力演化
成藏过程
Sichuan Basin
Penglai area
Sinian
Dengying Formation
Dolomite
Fluid inclusion
PVT simulation
Pressure evolution
Hydrocarbon accumulation process
