HIGH QUALITY SOURCE ROCKS OF NANTUN FORMATION IN WUERXUN DEPRESSION, THE HAILAER BASIN

Source rocks of Wuerxun Depression of the Hailaer Basin were investigated to characterize their biological developments,organic geochemistry.Together with wire logs and well cores analyses,three series of high quality source rocks in Nantun Formation were discovered.They all have good organic types,high abundance of organic materials and high hydrocarbon potentials.Combined with geological setting and referred previous study,the criterion of high quality source rocks was established(S₁+S₂) 20mg/g,chloroform bitumen "A"> 0.3%,TOC>5.0% and HC>700×10^-6,which was fit for the whole study area.Through the method of organic carbon log,the distribution of high quality source rocks was confirmed,which showed that the high quality source rock was mainly developed as thin layere in the Nantun Formation,especially in the upper part.In short,the development of the high quality source rocks contributed greatly to the pool forming.