摘要
广安气田是目前川中地区在上三叠统须家河组发现的最大气田,由于其地质条件特殊,对该气田天然气的成藏机理和富集条件一直认识不清。根据大面积成藏的定义,结合广安气田的地质特征,认为广安气田具有大面积成藏的特征。从气田烃源岩和储层的结构、气层分布特征、裂缝与气藏分布的关系以及包裹体的测试分析入手,认为大面积成藏的主要条件为平缓构造背景下,源储的大面积间互;有效储层的分布范围控制了气层的分布,构造起伏与裂缝发育有利于气层的分布与产能的提高;煤系地层的吸附解析机理和平缓构造造成晚期构造抬升是大面积成藏的重要条件。这一认识与前人关于构造抬升对油气成藏不利的观点不同,将增加抬升区油气成藏的资源潜力。
Guang'an gas field is the largest gas discovery in the Xujiahe formation in the central Sichuan basin so far. Its hydrocarbon pooling mechanism and enriching conditions are still unclear due to its special geologic conditions. According to the definition of large-scale accumulation and in combination with its geologic features,Guang'an gas field is believed to be a large-scale gas accumulation. Based on analyses of the architectures of source rocks and reservoirs,the distribution of gas layers,the relationship between fractures and gas reservoir distribution and the test results of inclusions,the large-scale interbedding of source rocks and reservoirs in a gentle structural setting is the major condition for large-scale hydrocarbon accumulation. The distribution of the effective reservoirs controls the distribution of gas layers. Structural relief and fracture development are favorable for the distribution of gas layers and enhancement of productivity. Desorption of coal measures and the late uplifting of the gentle structure are important factors for large-scale gas accumulation. This understanding is different with the previous knowledge that uplifting is unfavorable for hydrocarbon pooling,and it can enlarge the resource volume of the uplifted area.
出处
《天然气工业》
EI
CAS
CSCD
北大核心
2009年第6期19-22,26,共5页
Natural Gas Industry
基金
国家重点基础研究发展计划(973计划)(编号:2007CB209504)的资助
关键词
四川盆地
须家河组
广安气田
大面积成藏
地质特征
形成条件
Sichuan basin,Xujiahe formation,Guang'an gas field,large-scale accumulation,geologic condition,forming condition
