Source Rock Evaluation Of Tight Oil In The Permian Lucaogou Formation,Jimsar Sag,Junggar Basin

The Lucaogou Formation in Jimsar Sag has been identified as one of the most favorable areas for tight oil development in China.In this study a total of 192,drill core samples were collected from fifteen(15)exploration wells drilled in the Lucaogou Formation with the purpose of evaluating the source potential and identify favorable hydrocarbon accumulation areas.Analytical techniques performed includes;Rock-Eval pyrolysis,Induced Coupled Plasma Mass Spectroscopy(ICP-MS),Gas Chromatography(GC)and Gas Chromatography-Mass Spectrometry(GC-MS).Based on the results of this research work the Lucaogou Formation consists of organically rich,widespread source rocks in close contact with potential reservoirs.The organic richness is indicated by total organic carbon(TOC)values ranging from 2-21%and above minimum chloroform bitumen "A" values.Type I and type II organic matter dominates.Thermal maturity measurements;vitrinite reflectance values between 0.65-1.07%Ro,indicate that the Lucaogou Formation is at peak to late stage thermal evolution.Biomarkers(Pr/Ph,Pr/n-Cp and Ph/n-C18)and n-C27,n-C28 and n-C29 sterane analysis indicates deposition in anoxic,hyper-saline lake environment.This is supported by V/V+Ni ratio which ranged from 0.62 to 0.91,V/Ni ratio ranging from 1-10 and V/Cr ratio<4.REE pattern is similar indicating some provenance for studied rock units.Reservoir physical parameter varies and type I,II and III reservoir types are present.Several areas with good potential for oil productivity "sweet spots" are present.