SOURCE ROCK EVALUATION OF TAIZHOU FORMATION IN HAIAN SAG, NORTHERN JIANGSU BASIN

Source rock quality and exploration potential of the Taizhou Formation in the Haian Sag of the Northern Jiangsu Basin have puzzled geologists.Based on sampling analyses,organic geochemical profile of the formation has been set up.Source rocks are evaluated and exploration potential is predicted.Dark mudstone in the middle and upper section of the 2nd member of Taizhou Formation is not very contributory for reservoir.As to mudstone and muddy limestone at the bottom of the 2nd member of Taizhou Formation,average organic carbon content is high(2.32%).Kerogen is sapropel type or mixed type mainly composed of sapropel.It is in the low maturity to maturity stage and is a set of excellent source rock.Reserve of the Haian Sag is 4 242×10⁴ t,and remnant recoverable reserve is 1 358×10⁴ t,indicating good exploration prospect.