Analysis Of Petroleum Play And Resources Evaluation In The North Ustyurt Basin

The North Ustyurt Basin is one of the most potential petroliferous basins in the Middle Asia,which has a great amount of undiscovered recoverable reserves.According to the newest IHS,USGS data,this paper applies the petroleum analysis method,combining with the location,resource rock and reservoirs data of all 51 discovered fields that already in production,divides the whole petroleum resources in to 8 plays in the North Ustyurt Basin.Based on a series of evaluation parameters,with approaches of Monte Carlo method and Exploration trend extrapolation,we calculate the undiscovered recoverable reserves of target basin.4 petroleum systems are recognized,in which the PrecaspianJurassic petroleum system and Middle Jurassic-Oligocene petroleum system are most important.Regionally,the discovered oil and gas are mainly distributed in the North Buzachi Uplift,Kultuk Trough,Chelkar Trough and Sudochiy Trough,with feature of “oil in the West and gas in the East”.Stratigraphically,they are most reserved in the Middle Jurassic sandstone/ siltstone and Lower Cretaceous sandstone.The result of petroleum resources assessment show that undiscovered oil,gas and condensate resources amount to 515.93 MMbbl?1166.22 BCF?7.27 MMbbl,in total equals to 717.58 MMboe.In conclusion,the most potential plays are North Buzachi Jurassic play,North Buzachi Lower Cretaceous play and Ustyurt Middle Jurassic play.