Research On The Geochemical Features Of Aer Sag

The single sag of Erlian basin is characterized with small scale resource,severe variation of sand body and physical properties,and complicated reservoir forming conditions,which means to increase reserves and to enhance production will give priority to back-up sags.As discovered sags are deeply explored,it is increasingly difficult to discover new reserves.Therefore,it is badly in need of breakthrough in Erlian basin to back-up reserves.Locating the peripheral region of Erlian basin,the unexplored Aer sag of Bayinbaolige uplift is the key target.The 3D seismic is covering area 400.4km2 for Aer sag,almost the whole lease.Total 29 exploration wells have been drilled.Total 7 wells have been systematically analyzed on geology.Over 5,000 samples from more than 20 wells have been analyzed on 12 items in laboratory.Information like petroleum distribution,source,migration,accumulation and resource distribution have been achieved through analyzing quantities of collected and sorted data.The amount of source rock has been determined through studying source distribution and scale.The major source has been found through analyzing quantity,quality and thermal evolution of organic matter.The features and distribution prospects of various generated oil have been determined through studying physical properties,geochemical features and generation.The migration pathway has been determined through studying features of petroleum and source rock.The forming conditions and source of CH4,CO2,H2 S have been determined according to forming conditions and features of natural gas.The oil/gas accumulation and migration rules have been revealed through correlation between oil/gas and rocks and studying their accumulation features,providing evidence for scale reserves.The remaining resource distribution has been predicted through reserves estimation of Aer sag.All of the achievements have supported in technical for further exploration and development in this region.The final results indicate matured Teng'er formation and Aershan formation in Aer sag are developed.The oil threshold is equivalent to the bottom of Teng'er formation in depth of1,250 m.Therefore,it is probably that petroleum can accumulate within the interval from Paleozoic formation to Tengyi formation and be trapped as long as the trap condition is favorable.