A Three-dimensional Stratigraphic Numerical Forward For The Lower-mid Ordovician Formation Of Yubei Area,Tarim Basin

Sedimentary numerical simulation,by means of model building and stimulation validation,can reappear stratigraphic deposition procedure and analyze the spatial variation characteristics in the process of deposition.Hydrocarbon discovery of the Lower-Middle Ordovician in Yubei Area,Tarim Basin is mainly concentrated in fault zone and it remains unclear whether there are planar reservoirs under the T74 interface.On the basis of comprehensive analysis of core,sedimentary facies,paleo-water depth,paleo-subsidence and using sedimentary simulation method,the forward sedimentary numerical modeling of the Penglaiba to Yingshan Formation in Yubei Area,Tarim Basin was studied with Dionisos software and reappear its sedimentary evolution process.By using forward sedimentary modeling,it is considered that there existed multi-periods of sea-level fluctuations in the Penglaiba to Yingshan Formation,which has experienced repeated exposures and developed multi-periods of short-term exposed karsts.With the global sea-level showing a rising trend on the whole,two units of sedimentation formed in the prograding carbonate ramp environment.The Penglaiba Formation deposited with intermittent exposure.In the lower part of Yingshan Sedimentation the water level changed deeply and open-platform developed in the South Yubei Area,while semi-restricted to semi-open platform developed in the North.In the upper part water became more open and intraplatform shoal formed.The result of planar reservoirs distributed along karsts in study area is signaficant in petroleum exloration and prediction of favourable reservois.