Paleoenvironment and Petrophysics Properties of Bajwan Formation at Kirkuk Oil Field, Northeastern Iraq
Abstract
The Bajwan Formation is one of the most significant formations of the Oligocene cycle and the oil resource in the Kirkuk region. The present study is based on samples taken from two wells; the first is (K-A), where the Bajwan Formation about (30 m thick), while the second is (K-B), about (26 m thick). The formation is composed of creamy-colored limestone and dolomitic limestone with a various hardness. Some sections are soft. The formation is made up of four microfacies; Non-Fossiliferous Lime Mudstone, Milioldal-bioclasts Lime Wacke-stone/Packstone, Rotalids Wackestone, and Miliolidal Lime Wacke-stone/Packstone. These microfacies show that the formation was formed at inner ramp carbonate tidal flat platform environment. The Gama Ray log is used to compute the volume of shale (V-Shale) of the Bajwan Formation after the shale influence is removed owing to porosity equation adjustment. Based on the results of the porosity values for both wells, the Bajwan Formation successions are categorized into two zones in the well K-B, good and very excellent porosity zones, and three zones in the well K-A, poor, good, and very good porosity zones.
