西藏——我国西部21世纪新的油气资源接替区

Tibet-A New Take-Over Region for Petroleum Resources of 21st Century in West China

根据西藏地区区域地质构造和油气地质特征,从含油气区及其含油气盆地分析着手,论述其含油气性。立足西藏地区油气成藏条件的特殊性,将西藏地质划分为柴达木(及边缘)、巴颜喀拉、羌塘-昌都、冈底斯、喜马拉雅等5个含油气区,并讨论了构造复杂地区油气资源评价的基本思路,提出含油气实体(盆地、残盆、构造残块、沉积残体)的概念,作为西藏地区油气资源评价的基本单元、油气勘探对象和评价核心。分析了西藏地区主要盆地的生烃量、远景资源量,并结合油气成藏的其他地质因素,特别是油气保存条件,对主要盆地油气远景进行论证,计算结果表明,该地区总石油资源量约90亿吨,展现了地区的美好油气勘探前景。提出羌塘盆地应作为西藏地区油气勘探首选实体,措勤、比如、昌都、岗巴-定日等盆地应作为勘探远景实体。

This paper discusses the petroliferous property of Tibet region in light of characteristics of its regional geological structure and petroleum geology with analysis of its petroliferous areas and basins. In view of the unique feature in petroleum accumulation condition, Tibet region can be divided into five petroliferous areas such as Qaidam (margin), Bayankelahan, Qiangtang-Changdu, Gondis and Himalayan ones. As for petroleum resource assessment of their complex structural areas, this paper proposes a concept of petroliferous body composed of basin, residual basin, remnant structural mass and relic deposit, which is regarded as the basic unit for petroleum resource assessment, the target for oil-gas exploration and the core of evaluation. In addition, this paper makes an analysis and estimation of hydrocarbon-generated amount, potential resource amount in main basins of Tibet. The result shows that the petroleum resources amount to 9 billion tons, revealing its bright future for exploration, in which Qiangtang basin should be selected as an optimal body, and other basins like Cuole, Biru, Changdu and Gonba-Riding could be as prospective bodies.