Evaluation of the Hydrocarbon-Generation Potential of Pabdeh-Gurpi in one of the Fields in Southwest Iran

Abstract

The type of hydrocarbon potential of formations and their generation power can be investigated- regarding different aspects- by using and studying various features of the Pabdeh and Gurpi Formations. The source rock nature of Zagros Basin is the most important characteristic of these formations, playing the role of caprock for Bangestan reservoirs in some areas. The purpose of this study is to evaluate of hydrocarbon-generation potential of Pabdeh-Gurpi in one of the fields in Southwest Iran. In this research, the application of 44 palynological slides from 22 samples (2 slides from each sample) of drilling debris extracted from these formations in Mansouri Field led to the identification and determination of the amount of organic materials existing in each palynological slide. The selected samples for using Rock-Eval pyrolysis indicated that organic matters with marine sources are dominant, and the assessed Van Krevelen plot depicts the presence of kerogen type II in them. The generation potential of samples in which, parameters have had acceptable values includes oil and gas and is generally determined from almost good to very good. The trend of hydrogen index variations against the oxygen index of samples determined the B and BC facies, which implies anoxic to relatively anoxic environment with an average sedimentation rate that confirms palynological results. The plot of total organic carbon against the hydrogen index shows that when the hydrogen rate increases, the total organic carbon will increase, and the considered well with high amounts of total organic carbon and hydrogen index would specify anoxic (recovery) conditions and good durability of organic matter.