全球不同类型大型气藏的开发特征及经验

据AAPG的资料,全球已发现的370个大气田集中分布在西西伯利亚盆地、波斯湾盆地、扎格罗斯盆地、卡拉库姆盆地、墨西哥湾盆地、卡那封盆地以及东西伯利亚盆地,分布在上述盆地的大型气藏占总数量的45%,其储量占到大气田储量的68.3%。在分析所有大型气藏资料的基础上,研究了大型气藏的数量、储量、地区、地层、圈闭类型、深度、发现时间等特征。依据"实用性、针对性和科学性"分类原则,围绕岩性、厚度、规模、物性、压力、流体等因素将大型气藏划分为5种类型:1厚层整装高渗透砂岩气藏,规模大、储层厚、物性好、或存在边底水;2低渗透砂岩气藏,规模大、物性差、一般不存在边底水;3边底水裂缝型碳酸盐岩气藏,规模大、裂缝发育、存在边底水;4高温、高压、高含硫"三高"气藏;5凝析气藏,压力温度异常、相态复杂、常常发生反凝析现象。厘清大型气藏的分布特征为我国天然气藏的勘探指明了方向,总结出的不同类型大型气藏的开发特征也为相同类型气藏的经济、高效、安全开发提供了宝贵的经验。

Characteristics and experiences of the development of various giant gas fields all over the world

According to the data of AAPG, the 370 discovered giant gas fields all over the world are mainly distributed in the West Siberian Basin, the Persian Gulf Basin, the Zagros Basin, the Karakum Basin, the Gulf of Mexico Basin, the Carnarvon Basin, and the East Siberian Basin. Giant gas reservoirs in these basins account for 45% of the total number in the world and their reserves account for 68.3% of the cumulative major field reserves. Therefore, we summarized all the data about those global giant gas reservoirs in terms of numbers, reserves, regions, formations, trap types, depth and discovery time. In light of the classification principle of practicality, directivity and scientificity, we classified giant gas reservoirs into 5 types in respects of the lithology, thickness, scales, physical properties, pressure, and fluid characteristics: (1) high-permeability and great-thickness sandstone gas reservoirs on a large scale, with favorable physical properties and edge bottom water; (2) low-permeability sandstone gas reservoirs on a large scale , with poor physical properties and free of edge-bottom water; (3) fractured carbonate gas reservoirs on a large scale, developed with cracks and edge-bottom water; (4) "three-highs" gas reservoirs with high pressure, high temperature and high sulfur content; and (5) condensate gas reservoirs with abnormal pressure and temperature and the phenomena of complex phases and retrograde condensation. This study will be a guidance to China’s exploration and development of more giant gas reservoirs and will provide precious experiences to the safe, cost effective and high-efficiency development of similar giant gas reservoirs.