Palynofacies Analysis and Hydrocarbon Generation Potential of Dokan and Gulneri Formations (Upper Cretaceous) from selected wells in Northern Iraqi Oil Fields

Abstract

Sixty five cutting samples from Dokan and Gulneri Formations in three subsurface sections from Khabbaz, Jambour and Taq-Taq oil fields at Northern Iraq have been selected to be studied optically and analytically from Palynofacies points of view. Four palynofacies types have been determined depending on the ratio of the existed palynomorphs, phytoclasts, amorphous and opaque organic materials. The suggested paleoenvironment of deposition for Dokan and Gulneri Formations is seems to be deposited in proximal to distal shelf environment and that depending on the ratio of the palynomorphs, amorphous and phytoclasts to each other. The optical examination of the organic matter revealed the slightly mature to mature condition of the organic matter (TAI between 3 and +3). The GC analysis also supported such a maturity condition as the Pr/Ph ratio for the studied sections was greater than 1 while the Carbon Preference Index (CPI) less than 1. TOC values of different depths have been determined and types of amorphous organic matter from their ability to hydrocarbon potential also pointed out optically. By connecting between maturity stage, quality and quantity of the organic matters in the Formations of Dokan and Gulneri in the studied sections a number of oil and condensate-wet gas zones have been detected at certain depths of each section.