塔里木盆地两种重要的圈闭型式及其与喜山期油气关系

TWO IMPORTANT TRAP TRPES IN TARIM BASIN AND THEIR RELATIONSHIP WITH HIMALAYAN PETROLEUM

在塔里木盆地众多的圈闭类型中，中生界披覆背斜圈闭和以下古生界为主的断块潜山（或潜山）圈闭是最重要的两种高产圈闭型式。此两种圈闭均主要形成于中生代，它们所富集的油气均主要是喜山期以来生成的油气。披覆背斜圈闭封闭样式为单封闭层整合型，而断块潜山（或潜山）圈闭封闭样式为不整合型（其中许多尚属多封闭层圈闭），故从理论上看，中生界披覆背斜圈闭封闭和储聚油气能力要优于古生界断块潜山（或潜山）圈闭，塔北勘探实践亦证明了这一点。

Various trap types have been formed in Tarim Basin during geological time.The two most important ones are drape anticline and block buried-hill trap types. In the dis-covered over 50 reservoirs,there are 23 drape anticline traps(45%)and 17 block buried-hill traps(33%).Drape anticline and block buried-hill traps develop widespreadly in Shaya uplifted area in NE Tarim and in the central uplifted area.The former were formed in Mesozoic,and the latter in Lower Paleozoic,especially in Lower Ordovician,and their cap rocks are Mesozoic or Carboniferous.The two trap types are closely related and usually exist in the same structure.Therefore in Tarim Basin,a single structure can have several trapsand/or reservoirs.Mesozoic anticlines are single conformable traps,while Paleozoic block buried-hillsare partly single unconformable traps and partly multiple unconformable traps. Explo-rations have showed that conformable traps are better than unconformable ones in capa-bility of seal and preservation. Hydrocarbon in the two traps mainly generated during Hi-malavan.