塔里木盆地哈得4油田成藏年代学研究

Geochronology of petroleum accumulation of Hade 4 oilfield,Tarim Basin

哈得 4油田是近年来在满加尔凹陷北部发现的第一个海相油田 ,一直被认为是喜山期形成的油藏。然而 ,根据包裹体测温、伊利石K/Ar同位素测年以及油气水界面追溯等多种方法对其成藏年代重新研究表明 ,该油田主力油藏石炭系CⅢ油藏主要为晚海西期形成的古油藏 ,C5薄砂层油藏则可能为喜山期由CⅢ油藏垂向调整形成的次生油藏。

Hade 4 is the first large marine oilfield discovered recently in northern Manjiaer depression of Tarim basin. It was previously regarded as an oilfield formed in Himalayan (Neogene) period. Nevertheless, evidence from fluid inclusions, K/Ar dating of authigenic illite in the reservoir and retrospection of oil-water contact has revealed that the CⅢ accumulation (the major accumulation in the oilfield) was formed in Late Hercynian, whereas the C5 accumulation might be a secondary one formed by vertical adjustment of the CⅢ accumulation in Late Himalayan. Such a conclusion is of significance to the exploration and evaluation of western Manjiaer.