开发非常规天然气是利用低碳资源的现实最佳选择

Development of unconventional natural gas:The best approach to low-carbon economy and resource efficiency

非常规天然气资源因其具有"低碳、洁净、高效、低污染"的特性,故而从严格意义上讲,也属于新能源的范畴。非常规天然气资源的埋藏、赋存状态与常规天然气资源既有相似之处,又有较大的差别,其主要的差别在于资源的"低品位"。权威专家估算的全球非常规天然气资源量为2 338.2×1012m3,约为世界常规天然气资源量(512.6×1012m3)的4.56倍,约为常规石油、天然气资源量的1.65倍。全球非常规天然气资源主要分布在加拿大、俄罗斯、美国、中国、拉美等国家和地区。以美国为代表的非常规天然气开采实践,经过近30年的不断探索,已经逐步形成了适用于非常规天然气开发的技术体系,中国在致密气开发方面也走在了世界前列。我国的非常规天然气(仅包含致密砂岩气、煤层气、页岩气和天然气水合物)资源量为280.6×1012m3,是常规天然气资源量(56×1012m3)的5.01倍。目前,中国的致密砂岩气已进入规模开发阶段,煤层气、页岩气的开发利用正在起步;天然气水合物等资源的基础研究工作也正逐步展开。中国非常规天然气的地质特点包括:①南北中广泛分布;②深中浅层系复合;③海陆相沉积兼有;④储层物性复杂;⑤一般与常规油气共生共存。总体来看,非常规天然气开发利用要取得成功,其关键是拥有低成本的技术体系和低成本的管理体系。结论认为:开发非常规天然气是利用低碳资源的现实最佳选择。

Unconventional natural gas belongs to,in the strict sense,a kind of new energy resources due to its advantages of low carbon and low pollution.Although some similarities between conventional and unconventional natural gas are the burial history and occurrence state,a big difference exists between them,unlike conventional natural gas,unconventional natural gas is usually classified as a kind of low-grade resources.According to the authorities,the global unconventional natural gas,mainly distributed in Canada,Russia,the USA,China,Latin America,etc.,is estimated to be 2338.2 bcm,being approximately 4.56 times of the world's total conventional gas resources(512.6 bcm) and 1.65 times of the world's oil and gas resources.After 30 years of unconventional gas exploitation practices represented by the USA,a complete technical system has gradually come into being.China has leaped into the front ranks of the world in tight sandstone gas recovery.The unconventional gas resources in China which only includes tight sandstone gas,coalbed methane,and natural gas hydrate has a volume of 208.6 bcm,being about 5.01 times of the domestic conventional gas resources(56 bcm).At present,China has started the scale commercial development of tight sandstone gas,while the recovery of coalbed methane and shale gas is still at the initial stage,and fundamental studies of other new energy resources like natural gas hydrate is gradually being developed.Furthermore,the geological features of unconventional natural gas resources in China are summarized as follows: ①they are widely distributed in the north,south and middle of China;②they are discovered in those compound strata with deep,medium,or shallow layers;③they are found to be accumulated in both continental and marine deposit;④the petrophysical properties of their reservoirs are complex;⑤they are commonly originated and co-exist with conventional oil and gas.In general,the key to achievements in developing the unconventional natural gas resources relies on a low cost technical system and management system.This paper concludes that the development of unconventional natural gas resources is the best approach to low carbon economy and resource efficiency.