Relationship Between Tectonic Evolution and Hydrocarbon in Hangjinqi Block of North Ordos Basin

Abstract

Little research on relationship between tectonic evolution and hydrocarbon had been done in Hangjinqi block of northern Ordos basin.In effect,tectonic evolution of studied area played an important role in upper Paleozoic hydrocarbon migration and accumulation.Based on former achievements,this paper focused on tectonic evolution of studied area and pointed out definitely that this area experienced five phases of tectonic evolution,including Archean-Paleoproterozoic basement formation,Mesoproterozoic-Neoproterozoic rift centralized development,Early-Paleozoic uplift denudation,Middle-Late Carboniferous-Triassic hedreocraton development and Meso-Cenozoic disproportionate development.In this studied area,tectonic framework of higher in northwest in early metaphase changed into higher in northeast at present.Tectonic evolution made an important role in upper Palaeozoic reservoirs.Paleohigh and its evolution controlled distribution and evolution of upper Paleozoic source rocks.Tectonic movement made upper Paleozoic reservoir tight generally.Basement shape and tectonic movement controlled development of structural traps.Tectonic evolution controlled hydrocarbon migration and accumulation in upper Paleozoic.Studied area experienced two periods of hydrocarbon generation and expulsion in Middle-Late Jurassic and Early Cretaceous up to now.Hydrocarbon migrated mainly northward and northeastward,respectively.Slope part in southern studied area develops source-contacting gas,while northern one develops conventional gas.