摘要
裂缝在四川盆地须家河组致密砂岩气田的形成过程中起到重要的作用。裂缝的发育特征与力学形成过程决定了其与致密砂岩有效储层的形成和天然气运聚之间的关系。围绕该问题,通过岩心观察与成像测井分析,研究了广安地区须家河组须六与须四段储层裂缝的发育特征。根据构造背景和区域应力场的研究,发现该区主要有两期构造裂缝,分别为燕山晚期褶皱伴生张裂缝与喜山期断层伴生剪裂缝。第1期裂缝的形成与烃源岩的大量生排烃时间相吻合,促进了该区有效储层的形成,同时也是天然气运聚成藏的通道,如广安5井区;第2期裂缝形成时间晚,储层已经致密化,裂缝必须与有效储层相结合,才能对气藏起到调整与定型的作用,如广安124井区。
The fractures have a great effect on gas migration and accumulation in compacted sandstone of Xujiahe Formation, the Sichuan Basin. Developmental features and mechanical formation process of fractures determined the relationship of effective reservoirs and gas accumulation in compacted sandstone. Based on it, the fractures in sandstone reservoirs of Tax^4 and Tax^6 in the Sichuan Basin are discusseded according to core observation and imaging logging analysis. According to researches of fractures character and regional stress fields indicated that there are two stages of fractures formation, which are tension fractures associated with folds in the late Yanshanian period, and shear ones associated with faults in the Himalayan period. In Well GAN5 area of Tax4 , the first stage of fractures is formed at the same time with peak hydrocarbon-generation period, therefore, the fractures can be favorable to the forming of effective reservoirs and the gas migration. However, in Well GAN124 area, the fractures are formed after the effective reservoirs occurrence, so the fractures must be comhinated with the effective reservoirs, and can adjust and reshape the gas reservoir which have already been formed.
出处
《石油实验地质》
CAS
CSCD
北大核心
2008年第6期585-590,共6页
Petroleum Geology & Experiment
基金
国家重点基础研究发展计划(973计划)项目(2007CB209504)
关键词
构造裂缝
形成期次
天然气成藏
广安气田
须家河组
四川盆地
structural fracture
forming period
gas accumulation
Guang＇an Gasfield, Xujiahe Formation
the Sichuan Basin
