中国致密砂岩气主要类型、地质特征与资源潜力

致密砂岩气已成为全球非常规天然气勘探的重点之一。中国致密砂岩气分布范围广,目前已在鄂尔多斯和四川等盆地实现了规模开发;致密砂岩气藏主要有低缓斜坡型、背斜构造型和深部凹陷型3种类型,其基本地质特征表现为以煤系源岩为主,生烃强度高,具有持续充注的气源条件;致密砂岩与烃源岩紧密相邻,大面积接触,以近距离垂向运移成藏为主;源储有效配置形成致密砂岩气大气区,局部富集。中国致密砂岩气的有利勘探面积约为32×104km2,可采资源量达(8～11)×1012 m3,目前中国致密砂岩气勘探开发技术已较成熟,具备加快发展的条件,在中国未来天然气发展中必将发挥重要作用。

Main Types, Geological Features and Resource Potential of Tight Sandstone Gas in China

Tight sandstone gas has become a focus of the global unconventional natural gas exploration.It is widely distributed in China.Until recently,Ordos and Sichuan basins have achieved the large-scale exploitation.Tight sandstone gas in China has mainly three types,including slop type,structure type and depression type.The tight sandstone reservoirs are mainly sourced by coal-measure rocks,and charged continually.The widespread source rocks and reservoirs interbed.Therefore,the gas can migrate vertically from source to adjacent reservoir.The intimate contact of source and reservoir forms the large-scale gas-bearing area,with"sweet spots" locally enrichment.The favorable exploration area of tight sand gas in China is 3.2×105 km2,with recoverable resources about(8～11)×1012m3.Currently,China has comparatively mature technology of the exploration and development of tight sandstone gas,having the conditions of accelerating the developing pace.Therefore,tight sandstone gas will play an important role in the future natural gas development in China.