Biomarker characteristics of oils from Garmian Oil Fields and potential Jurassic source rocks, Kurdistan,NE Iraq: implications for oil–oil and oil-source rocks correlation.

Volume 18 , Issue 2 , February 2016 , Pages 43-62

Authors

¹ Kurdistan Institution for Strategic Study and Scientific Research Department of Geology, School of Science, University of Sulaimani, Kurdistan

The Middle Jurassic Sargelu Formation in Sangaw North -1 (SwN-1) borehole, Sangaw

North Block, Garmian area, Kurdistan region, was used for geochemical analyses. Two

crude oils from PLK-8 and Sarqala-1 wells in Pulkhana and Sarqala oil fields, one

condensate from KM-3 well in Kor Mor gas field and seepage oil from ChiaSurkh oil

field were chosen for organic geochemistry investigation, oil-oil and oil-source rocks

correlation. Tectonically, the study area is located in the southeastern part of the Foothill

Zone in Zagros Fold Belt. The biomarkers ratios and molecular compound distributions

showed that the oils, condensate and rock extracted sample of Sargelu Formation were derived

from marine carbonate source rocks bearing marine algae and kerogen type II that deposited under

reducing condition. Low presence of gammacerane indicated normal salinity condition

during the depositions. The GC-FID traces of oils and condensate showed lack of any

remarkable biodegradation, but rock-extracted of Sargelu Formations is strongly

contaminated by polyethylene glycol according to the GC-FID chromatogram.

Compositional similarity of sterane, hopane, isopernoid and n-alkane compounds among

the crude oils and crude oils with extracted sample of Sargelu Formation suggested that

the oils might be sourced from the same or similar source rocks that deposited under

similar conditions. On the other hand, Sargelu Formation is supposed to be one of the

sources of the generated crude oils. However, the maturity-related parameters showed no

similarity between the crude oils and extracted sample of Sargelu Formation.

Statistics