Source Rock Assessment of Naokelekan Formation in Iraqi Kurdistan

Abstract

The Callovian-Kimeridgian Naokelekan Formation is a heterogeneous sequence consisting principally of bituminous shales with bituminous limestone and dolomitic limestones. It is 48 m thick maximally in some parts of the area. One hundred forty four rock and cutting samples from six outcrops and eight boreholes in different parts of Iraqi Kurdistan have been studied using the Rock-Eval technique with the primary purpose of assessing their potentiality as promising source rocks for petroleum. The outcomes of the Rock-Eval study for examined samples shows that TOC ranges from 0.4 to 18.8 wt. % and types II and III kerogens are the main components of organic matter.Qualitative evaluations are also done by textural microscopy used in assessing amorphous organic matter for palynofacies. The organic matters are mature that have thermal alteration index of 2.6-3.2 by Pearson's scale with palynomorphs of dark orange and light brown colors and Tmax ranges between 434 to 493ºC. Thus the Naokelekan Formation can be considered as a source rock for generation and expulsion of oil and/or gas that has been charged largely oil fields in the area.Maturity increases toward the northeastern part of the studied area. Furthermore, the study revealed that Naokelekan Formation is within dry gas and/or late oil zone in the eastern part, early oil window in the central part and immature in the western part of the studied area.

Hydrocarbon Potentiality and Depositional Environment of Naokelekan Formation in Binari Serwan-1 Well, NE-Iraq Using Infrared Factors and Palynological Analysis Evidence

“…and lotharingius sp. within the upper part of this formation signifies Callovian-Upper Oxfordian age [15].…”

Petroleum System Modelling of the Akri-Bijeel Oil Field, Northern Iraq: Insights From 1-Dimensional Basin Modelling

“…Mathematically calculated Tmax values and their equivalent %Ro values, as determined by Rock-Eval pyrolysis, were used for calibration. The Tmax values have been reported by Abdula (2015) and Abdula (2017b). It is reasonable to assume that the heat flow changed over time, but it has not been necessary to make assumptions about when the heat flow changed because the use of a constant heat flow over time has led to an appropriate context visualization of the %Ro value, as determined by EASY%Ro (Sweeney and Burnham, 1990).…”

Rock-Eval analysis and organic petrographical characterization of the Upper Jurassic Naokelekan Formation, northern Mesopotamian basin, Kurdistan Region-Iraq

“…Nevertheless, an additional aspect to consider is that the in-depth organic petrographical data presented within this paper correspond mostly to the bituminous strata of the lower parts of the Naokelekan Fm, as defined by Abdula (2016) and presented in Fig. 1b.…”