Study On The Accumulation Characteristics And Favorable Zones Of The Silurian In The Keping-northwestern Part Of The Tarim Basin

The Silurian in the Tarim Basin was uplifted and denuded due to the influence of tectonic movements.The existing research results show that the Silurian in the basin was severely damaged after early large-scale oil and gas accumulation,and a large amount of asphalt sandstone remains today.Therefore,compared with other layers in the basin,the research on the evolution of the Silurian hydrocarbon accumulation characteristics is relatively weak.The significant Silurian oil and gas discovery in well Xinsudi 1 on the Shajingzi fault zone in the northwestern margin of the basin has brought the Silurian oil and gas exploration to a new level.Based on the analysis of the geological characteristics of the existing Silurian oil and gas reservoirs in the northern Tarim Basin,this paper studies the petroleum accumulation elements of the Silurian Kepingtage Formation in the Keping-western Tarim area,and predicts favorable zones.The research results show that the Silurian Kepingtage Formation in the Keping-northwestern Tarim Basin was formed in a coastal-tidal flat environment,with thick sand bodies in the upper and lower members.Oil was charged during the late Caledonian,Hercynian,and Indosinian periods by the Cambrian and Ordovician source rocks,and natural gas was charged during the Himalayan period.Among them,the early and middle periods were destroyed,and the Himalayan period gas was the mainstay.The structural uplift and denudation of the northwestern Tarim Basin paleo-uplift are favorable for oil and gas migration and trap formation,and it is predicted that the accumulation and preservation conditions are good.The Silurian hydrocarbon accumulation in the study area is mainly controlled by geological factors such as traps,sand bodies,source rocks and transport systems.Three favorable zones of the Kalpintag Formation were selected in the northwestern margin of the basin by superimposing key accumulation elements.