亚洲特提斯域油气聚集地质特征

Geological characteristics of the hydrocarbon accumulation in the Tethyan tectonic domain

关键词:  亚洲  特提斯域  油气

Key words:  Asia  Tethyan realm  petroleum

摘要:

特提斯域含油气性,特别是亚洲特提斯域油气聚集地质特征,举世瞩目。本文从亚洲特提斯域地质演化、构造单元划分着手,讨论油气地理分布、油气分布与盆地类型、油气盆地与沉积环境、油气分布与盆地保存的特点,进而对亚洲特提斯域油气富集基本因素进行总结。亚洲特提斯域含油气盆地是特提斯洋形成、演化、造山和消亡过程的沉积-构造产物,其盆地成因和赋存的油气具有特提斯固有的特色。亚洲特提斯域油气地理上主要分布于西亚段南带,其次为西亚段北带、东南亚段中带,再次为中亚段。分析发现,亚洲特提斯油气分布,就盆地类型而言,主要与前陆盆地、克拉通边缘盆地相关;就成烃物质的沉积-构造环境而言,多位于古赤道与45°古纬度之间,盆地形态主要与台地、环形坳陷、线形坳陷沉积-构造环境相关。亚洲特提斯域油气分布与盆地保存关系极为密切,盆地保存是盆地油气评价的先决条件。文章把亚洲特提斯域油气富集基本因素归纳为两点,一是盆地演化过程中具备广阔平缓、长期保持被动陆缘沉积-构造环境,二是盆地演化末期直至现今保持沉积物被埋藏、保存的状况。

Abstract:

It has long been known for the oil reservoir potential in the Asian Tethyan tectonic domain. The present paper deals in detail, on the basis of geological evolution and division of tectonic units, with the geographical distribution of oil and gas, basin types, sedimentary environments, and hydrocarbon accumulation and preservation in the petroleum basins in the Asian Tethys.These petroleum basins are the tectonic-sedimentary products generated during the initiation, culmination and termination of the Tethyan Ocean. Geographically, the majority of the petroleum reserves in the Asian Tethys reside in the southern zone of West Asia, followed by the northern zone of West Asia, the central zone of Southeast Asia and Central Asia, or in foreland basins and pericratonic basins in the areas between the palaeoequator and 45° of the palaeolatitude.The basin morphology tends to be associated with the sedimentary-tectonic environments such as platforms, ring and linear depressions.The preservation of the above-mentioned basins may be considered as a prerequisite to basinwide petroleum assessment. The controlling factors for hydrocarbon accumulation include the broad and gentle continental marginal sedimentary-tectonic settings, and long-tern burial and preservation of the basin sediments.