Palynofacies and Source Rock Evaluation of Baluti Formation (Late Triassic) in two selected wells, in Duhok Governorate, Iraqi Kurdistan Region.

Abstract

Palynofacies and petroleum potential of Baluti Formation (Late Triassic) were studied from the sum of 37 samples, which have been taken from two exploration wells Atrush-1 and Sheikhan-1B, near Duhok city, Iraqi Kurdistan Region. These cutting samples were chosen to be studied for optical and analytical analysis.

Baluti Formation at the current study mainly consists of green to grey shale, dolomite, anhydrite and dolomitic limestone. Three palynofacies were distinguished in this formation, depending on the percentages of Amorphous Organic Matter, Phytoclast and Palynomorph. The Palynofacies-1 was deposited in Heterolithic oxic shelf, Palynofacies-2 was deposited in shelf to basin transition and Palynofacies-3 was deposited in Mud-dominated oxic shelf.

Thermal Alteration Index (TAI) is applied and showed early stage of maturation, the estimated paleotemperatures was not more than 80 °C. The major dominant types of AOM kerogen were type B and C and lesser amounts of type A and D, which mainly indicates gas prone. Infrared executed for particular samples, the results were showing type kerogen II to III (with more tendency to II).

 

Moreover, Pyrolysis technique done for particular chosen samples, according to Total Organic Carbon, the percentage of TOC was higher in Sheikhan-1B, resembling in fair source rock, while Atrush-1 showed poor source rock. In addition, according to Pyrolysis parameters, the type of organic matter in Sheikhan-1B is type III to IV and Atrush-1 contains type II to III. Finally, Sheikhan-1B has ability to generate gas (gas prone), while Atrush-1 has ability to generate mixed oil-gas.

 

posted: 9/10/2016