四川盆地二叠系和三叠系礁滩天然气富集规律与勘探方向  

Gas accumulation and exploration direction of the Permian and Triassic reservois of reef-bank facies in Sichuan Basin

作　　者：郭旭升[1] 黄仁春[1] 付孝悦[1] 段金宝[1] 

机构地区：[1]中国石化勘探南方分公司,四川成都610041

出　　处：《石油与天然气地质》2014年第3期295-302,共8页Oil & Gas Geology

摘　　要：通过系统的天然气组分、碳同位素以及微观薄片、包裹体分析,明确了二叠系和三叠系礁滩气藏中天然气主要为原油二次裂解气,龙潭组(吴家坪组)为天然气藏的主力烃源岩层,气藏经历了早期岩性古油藏聚集、古原油裂解和天然气调整再聚集3个阶段;天然气藏(田)具有多元供烃、近源聚集、岩性控藏、气油转化、晚期调整的成藏富集模式,现今气藏的富集主要受控于3个方面:一是二叠系烃源岩的生烃灶分布控制了油气来源的充足程度;二是礁滩相储层的分布与规模控制了油气聚集的场所与规模;三是晚期保存条件决定了天然气的最终聚集。通过系统总结已发现礁滩气藏(露头)沉积储层、油气富集规律,进一步探讨了下步勘探发展的方向,认为长兴组、飞仙关组和嘉陵江组台缘礁滩、台内浅滩和下二叠统浅滩勘探领域仍存在良好勘探前景。Through systematic analysis of gas component , carbon isotope , thin section and inclusions , we found that the Permian and Triassic reef-bank reservoirs are dominated by natural gas from secondary cracking of crude oil .The Longtan Formation （ Wujiaping Formation ） is the major source rocks .The gas reservoirs experienced three stages ,namely earlier oil accumulation in ancient lithologic reservoirs ,ancient crude oil cracking and gas adjusting and re-accumulation.The hy-drocarbon accumulation pattern is characterized by multiple hydrocarbon supply ,accumulation near the source ,lithology reservoirs,oil-gas conversion and later adjustment .And the present day gas reservoirs are mainly controlled by three fac-tors.Firstly,the hydrocarbon kitchen of the Permian source rock controls the adequacy of oil -gas source.Secondly,the distribution and scale of reservoirs of reef-bank facies control the scale and location of hydrocarbon accumulation .Third-ly,later preservation conditions determine the finally accumulation of gas .By systematically summarizing the sedimentary characteristics and hydrocarbon accumulation conditions of the discovered reef -bank gas reservoirs （ outcrops ） ,we believe that reservoirs of platform margin reef-bank facies ,intra-platform shoal facies and the Lower Permian shoal facies are the favorable targets for further gas exploration .

关 键 词：碳酸盐岩 礁滩气藏 二叠系 三叠系 四川盆地 

分 类 号：TE122.3[石油与天然气工程—油气勘探]