南亚油气分布特征及成藏因素探讨

An Exploration for the Oil and Gas Distribution and Geological Factors in South Asia

南亚作为世界大油气区之一,经历了漫长的构造沉积演化,尤以新生代以来的构造活动最显著。本文以获取的最新油气田储量资料为基础,探讨了南亚油气资源在不同类型盆地、不同年份、不同层系和不同圈闭类型的分布特征。统计分析表明,南亚油气勘探集中于上世纪五十年代以后,且整体呈增长趋势;前陆盆地油气最富集,其次是被动陆缘盆地;油气在1 km^2 km埋深最富集;以构造圈闭为主;储层主要分布在新生界;储层岩性以碎屑岩和碳酸盐为主。南亚油气分布特征与其构造沉积演化史密不可分,尤其是印度板块裂离后形成被动陆缘向北漂移最后与欧亚板块碰撞,直接影响了烃源岩成熟度和储层分布以及油气的成藏聚集与运移,对油气分布起着决定性作用。

As one of the world＇s largest oil and gas area, South Asia goes through a long lasting tectonic and sedimentary evolution, whose tectonic activity is especially significant in Cenozoic period. Based on the up-to-date reserve data of oil and gas fields in South Asia, this paper documented the oil and gas distribution features in terms of basin and trap type.It also characterized the areal and strati-graphic distribution of discovered oil and gas reserves. Statistical analysis showed that oil and gas prospecting started in South Asia after 50 s 20 th century, and kept increasing. The foreland basin was the basin type with the richest oil and gas resources, followed by the passive margin basin. Oil and gas were embedded the depth of 1km to2 km and concentrated mainly in the structural trap. Reservoirs were mainly distributed in the Cenozoic and reservoir lithology accounted for most of classic rock and carbonate. South Asia＇s oil and gas distribution characteristics were closely related to its tectonic sedimentary evolution, especially the South Asia plate＇s collision with the Eurasian plate to influence directly on the maturity of hydrocarbon source rock, reservoir distribution and accumulation and migration of oil and gas. It could play a decisive role in hydrocarbon distribution.