Scientific and technical journal

«Geology, geophysics and development of oil and gas fields»

ISSN 2413-5011

Geology, geophysics and development of oil and gas fields
Diagenetic effects in low-porous limestones of shoals facies, lagoons and their transitional varieties of the Mishrif formation of the West Qurna-2 deposit

UDC: 553.98(567)
DOI: 10.33285/2413-5011-2022-12(372)-13-23

Authors:

DMITRIEV SERGEY A.1,
KHAIRULLIN ILSHAT I.2,
ISAEV ALBERT B.3

1 LUKOIL-Engineering LLC, Moscow, Russia
2 PJSC "LUKOIL", Moscow, Russia
3 LUKOIL Mid-East Limited, Moscow, Russia

Keywords: carbonate reservoirs, well logging, facies model, diagenesis, field logging, core, karst processes

Annotation:

The study is aimed at identifying intervals of low-pore carbonate reservoirs in the section of the Mishrif formation (Cenomanian stage) of the West Qurna-2 deposit (Republic of Iraq), which are characterized by improved reservoir properties as a result of their modification by secondary digenetic leaching processes. Qualitative characteristics and features of such reservoirs are considered according to well logging data, field geophysical surveys, core samples and their quantitative prediction based on wells data. By combining core and well logging data, as well as relying on regional data, the study substantiated the lithofacies and sequence stratigraphic models of the Mishrif formation deposits and established the most probable causes of the development of diagenetic processes in the upper part of the section that improve the initial reservoir properties of the rocks. To visualize the spatial distribution of leaching zones, maps of the thicknesses of low-pore leached reservoirs estimated according to well logging data were built.

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