鄂西—渝东地区飞三段天然气成因与成藏阶段  

Natural Gas Origin and Accumulation Stages of the Third Member of Feixianguan Formation in Western Hubei and Eastern Chongqing Area

作　　者：舒志国[1] 

机构地区：[1]中国石化江汉油田分公司,湖北潜江433124

出　　处：《现代地质》2013年第1期165-171,共7页Geoscience

基　　金：国家科技重大专项项目(2011ZX05005-003-009HZ)

摘　　要：飞三段是鄂西—渝东地区海相碳酸盐岩层系的主力产气层,系统研究飞三段的天然气成藏阶段与主控因素,对该区飞三段的天然气勘探具有指导意义。利用天然气组分和稳定碳同位素资料、烃源岩的干酪根碳同位素资料以及流体包裹体均一温度资料,在阐明油气的成因与来源、烃源岩的生烃史和油气充注史的基础上,结合构造演化史和圈闭演化史,划分了天然气的成藏阶段,并总结了天然气成藏的主控因素。结果认为:飞三段天然气主要为二叠系烃源岩生成的原油的二次裂解气;天然气的成藏经历了古岩性油藏的聚集(190～160 Ma)、古油藏裂解与古岩性气藏形成(160～140 Ma)、天然气调整再聚集形成今构造—岩性复合气藏(140 Ma—现今)3个阶段;沉积期暴露浅滩相储层的规模决定了古油藏的规模,晚期天然气的调整再聚集过程中的保存条件决定了天然气的最终聚集。The third Member of Feixianguan Formation （T1f^3） is the main gas producing formation of marine carbonate strata in western Hubei and eastern Chongqing area. Systematic research on natural gas accumulation stages and main controlling factors should be helpful for natural gas prospecting in this area. Based on natural gas composition and stable carbon isotope, kerogen carbon isotope, and homogeneous temperature of fluid inclu- sions data, this paper discussed the origin and source of the natural gas, hydrocarbon generating and petroleum charging history. Finally, gas accumulation stages and the main controlling factors of gas accumulation were ana- lyzed according to the regional structure and local trap evolution histories. Following conclusions can be drawn. The natural gas of T1f^3 was mainly secondary cracking gas of the crude oil generated from the Permian source rock. Natural gas accumulation can be divided into three stages： oil accumulation of paleo-lithologic reservoir （190 Ma to 160 Ma）, oil cracking and gas accumation of the paleo-lithologic reservoir （160 Ma to 140 Ma）, and present structural-lithologic gas reservoir formed by the reaccumulation and adjustment of gas （ 140 Ma to present）. The scale of the exposure shoal reservoir effects the scale of paleo-oil reservoir, and the reservation condition during the natural gas remigration and accumulation should be vital for the final gas accumulation of present gas reservoir.

关 键 词：鄂西-渝东 飞三段 天然气 成藏阶段 主控因素 

分 类 号：TE122.1[石油与天然气工程—油气勘探]