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人们已熟知世界常规天然气分布和资源量。然而,它不像石油常受检于市场,只有天然气被广泛利用并且占有较大能源市场时,许多细节才能搞清楚。可采常规天然气量与原油相当,即12000Tft~3的最终天然气资源相当于2273Gbbl原油。然而,到目前为止天然气的产量还不到原油的一半,并且多年产在北美。像其它所有的天然资源一样,天然气的分布相当没有规律,极个别地区却占有绝大部分的资源。未来的两个主要天然气产区是中东和西西伯利亚的巴伦支海,这些地区石油的储运设备已非常完善,但是,即使有市场,储运天然气的基础设施还很薄弱。同石油一样,天然气臧的形成受盆地五个独立的地质变量限制:气源岩、储集岩、圈闭、盖层和形成时间。在某种程度上,生储盖条件受气候的控制,温暖气候有利于气源岩、碳酸盐岩储层和盐岩盖层的形成。因此,已发现的石油和天然气主要来自接近赤道气候条件形成的沉积岩。考虑到板块构造发展,南半球仅在晚中生代到新生代处在低纬度。这样就限制了油气在生成岩当中形成的潜力。一般来说,起源于烃源岩并储盖在同一岩石中的天然气同样受纬度的制约。但炭质气源岩可能更易于在温带形成。常规天然气预测图显示,世界潜在丰富的含油气盆地接近500个。
People are familiar with the world’s conventional gas distribution and resources. However, unlike oil, which is often not inspected on the market, many details can be understood only when natural gas is widely used and has a large energy market. The amount of natural gas recoverable is comparable to that of crude oil, ie the final natural gas resource of 12,000Tft ~ 3 is equivalent to 2273Gbbl crude oil. However, so far output of natural gas is less than half that of crude oil and many years are produced in North America. Like all other natural resources, the distribution of natural gas is quite irregular and in very few areas it occupies the vast majority of resources. The two main gas producing areas in the future are the Barents Sea in the Middle East and West Siberia, where oil storage and transportation facilities are well established, but even with markets, the infrastructure for storing and transporting natural gas is weak. Like oil, the formation of natural gas is limited by five independent geological variables in the basin: gas source rocks, reservoir rocks, traps, cap rocks and formation time. To some extent, the conditions of reservoir-capment are controlled by the climate and the warm climate is favorable for the formation of gas source rocks, carbonate reservoirs and salt rock caprocks. As a result, the oil and gas discoveries have come mainly from sedimentary rocks close to the equatorial climatic conditions. Taking into account the tectonic development of the plate, the southern hemisphere only in the late Mesozoic to Cenozoic at low latitudes. This limits the potential for hydrocarbons to form in the rocks. In general, natural gas originating from source rocks and stored in the same rock is also subject to latitude. However, carbonaceous source rocks may be more easily formed in temperate zones. The conventional gas forecast shows nearly 500 potentially rich petroliferous basins in the world.