Integration of Reservoir Performance and Geoscience Studies in the History Match of a Complex Carbonate Reservoir – a Case Study from the Magwa Marrat Reservoir - Kuwait

Jadi, Menayer Al (Kuwait Oil Company, Kuwait) | Kumar, Pranay (IFP Middle East Consulting, Bahrain) | Lislaud, Frederic (Beicip Franlab, France) | Robert, Joël (Beicip Franlab, France) | Alessandroni, Mauro (Beicip Franlab, France) | Lefebvre, Christian (IFP Middle East Consulting, Bahrain) | Groen, Vincent de (Beicip Franlab, France) | Vigier, Louise (Beicip Franlab, France) | Datta, Kalyanbrata (Kuwait Oil Company, Kuwait) | Hafez, Karam (Kuwait Oil Company, Kuwait) | Taneja, Hans (Kuwait Oil Company, Kuwait) | Bhattacharya, Muktibrata (Kuwait Oil Company, Kuwait) | Bond, Deryck (Kuwait Oil Company, Kuwait)

OnePetro 

Abstract

An integrated reservoir study of the Magwa Marrat reservoir has been completed recently. This study was carried out to support the continued development of the reservoir, in particular the planning of a secondary water flood.

The initial part of the study concentrated on reservoir characterization and reservoir performance over a long period, in the order of 30 years, of primary recovery, followed by analysis of a recent pilot water flood. A better understanding of the controls of flow and the role of fracture corridors and diffuse fractures was achieved through and integration of geophysical, petrophysical and dynamic data including tracer tools and in particular through a dynamic model of the water flood pilot. The uncertainties related to structural extension, especially on the flanks of the field and related to aquifer support, were also recognized.

Later on static and dynamic models were built, first around the pilot water flood area and then for the entire reservoir. These models have been used for development planning.

This paper gives an overview of the integrated study but concentrates on the features, detailed below, that were key to better understanding the fluid flow physics and to achieve a satisfactory "history match".

A single porosity model that accounted for matrix permeability, local enhancement to permeability within restricted fracture corridors and the effect of diffuse fractures in "tight" zones was adopted. Matrix permeability values were based on the results of a rock typing study. Static and dynamic pressure, oil production and water movement matching was achieved by making limited and realistic changes to fracture zone permeability, fracture zone extent and some fine tuning of matrix permeability. Well productivities, pressure transient tests, interference tests and production log data were used to guide and validate the history match.

Water-cut match was further improved by making reasonable changes to the structural model in regions where significant structural uncertainty was recognized.