«Proceedings of Gubkin University»

DIAGENESIS PROCESSES AND THEIR EFFECT ON RESERVOIR PROPERTIES OF THE LOWER MIOCENE RESERVOIRS IN THE GARMIAN BLOCK, KURDISTAN, IRAQ

UDC: 552.5(419)
DOI: 10.33285/2073-9028-2019-2(295)-18-29

Authors:

¹ Gubkin Russian State University of Oil and Gas (National Research University), Moscow, Russian Federation

Keywords: diagenesis processes, reservoir properties, lower miocene forma-tions, Jerib, Dhiban, Euphrates, Kurdistan, Iraq

Annotation:

In the Iraqi Kurdistan, the most significant oil deposits are concentrated in the Cretaceous and lower Miocene sediments. In this paper we used data on the recently discovered Sarqala and Shakal oilfields. The Lower Miocene formations of Euphrates and Jeribe are the main target objects of the tertiary oil and gas system in the Iraqi Kurdistan. The formations are composed of carbonates with a few interbeds of evaporites of the Dhiban formation. The rocks of the studied formations are affected by a number of diagenetic processes, including dolomitization, micritization, cementation, neomorphism, leaching, compaction, styllolitization, pyritization and anhydration. The most significant of these are the processes of dolomitization, dissolution, neomorphism, cementation and compaction. The processes of dolomitization and dissolution improve the quality of reservoirs, while neomorphism, carburization and compaction have a negative effect. Fracturing plays a significant role in the increased porosity and permeability of the rocks studied, mainly in calcareous mudstone and wackestone.

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