石油与天然气地质 ›› 1996, Vol. 17 ›› Issue (2): 87-95.doi: 10.11743/ogg19960201

• 论文 •    下一篇

青藏高原油气地质条件与勘查方向

何治亮, 刘继顺   

  1. 地质矿产部石油地质综合大队
  • 收稿日期:1995-06-07 修回日期:1995-12-21 出版日期:1996-06-25 发布日期:2012-01-16
  • 基金项目:

    地质矿产部石油地质海洋地质局资助

PETROLEUM GEOLOGICAL CONDITION AND EXPLORATION DIRECTION OF QINGZANG PLATEAU

He Zhiliang, Liu Jishun   

  1. Comprehensive Research institute of Petroleum Geology, MGMR, Jingsha, Hudei
  • Received:1995-06-07 Revised:1995-12-21 Online:1996-06-25 Published:2012-01-16

摘要:

青藏高原位于特提斯构造沉积域东段,晚元古代以来,先后经历了元古洋、古特提斯洋、新特提斯洋、印度洋四大演化阶段,导致了不同构造部位多成盆期和多种原型盆地的复合与叠置,构成多个潜在的含油气领域。上新世以来,强烈的挤压作用和复杂的变盆改造使高原内部油气保存与成藏条件更为复杂,保存与散失、有效与无效成藏,以及寻找相对稳定的构造区块成为评价的关键。以伦坡拉第三纪陆相盆地和羌塘中生代海相残余盆地为代表,构成了青藏高原两大油气勘探领域。

关键词: 青藏高原, 特提斯域, 盆地, 油气条件, 勘探方向

Abstract:

Qingzang Plateau is an important part of Tethys domain between paleo-Eurasia and Gandwana. The petroleum geological condition there is complicated due to the regional framework of nearly E-W trending arc faults alternated with faulted terrains, the complex crust-mantle architecture and intensive neotectonic movements within the plateau. Since Cambrian, the plateau has undergone multi-cyclic geological evolution of four major stages: Proterozoic ocean, palaeo-Tethys, new Tethys and indian Ocean. The composition and overlapping of the prototype basins in different places and different periods within the plateau formed potential oil-bearing regions. Among them, Northern Himalaya is composed of overlapped cratonic depression-intercontinental rift-passive continental margin-peripherral foreland basin: the Northern Gangdise is composed of superposed cratonic rift depression-back arc basin-remnant back are basin-strike slip pull apart basin : Northern and Southern Qiangtang consist of superimposed cratonic rift depression-quasipassive continental margin-strike slip and compressional basin, and cratonic depression-passive continental margin-peripheral foreland basin and strike slip basin respectively. On the setting of intensive compressional deformation and uplifting,the basins show unique stratigraphic distribution,tectonic framework and structural patterns,and complex oil-gas-water system. Various blocks in the plateau have multiset of source rocks and reservoirs, but the organic matter of the source rocks is a little overmatured. As the plateau uplifted, the period of high geothermal environment was little later than that of tectonic deformation. This might probably result in secondary oil generation and late stage pooling in some places within the plateau. Mudstones and shales that widely developed there, gypsolyte distributed in local places and permafrost formed multi-type of source-reservoir-cap rock assemblages. Different types of structural, lithologic and sedimentary traps are targets for oil and gas exploration. Strategic break-through in oil and gas exploration could be achieved by selecting stable blocks with fine oil-gas-water system and overlapped basins with favourable matching within the plateau.