Modeling and History Matching of a Fractured Reservoir in an Iraqi Oil Field

Abstract

In recent years the interest in fractured reservoirs has grown. The awareness has increased analysis of the role played by fractures in petroleum reservoir production and recovery. Since most Iraqi reservoirs are fractured carbonate rocks. Much effort was devoted to well modeling of fractured reservoirs and the impacts on production. However, turning that modeling into field development decisions goes through reservoir simulation. Therefore accurate modeling is required for more viable economic decision. Iraqi mature field being used as our case study. The key point for developing the mature field is approving the reservoir model that going to be used for future predictions. This can be achieved via History Matching. The production of this field is mainly from fractures, and it showed unfavorable decline during the production life from 1952. Thus, well modeling is necessary for developing the field, including history matching. This study employed a three-dimensional three-phase black-oil dual-porosity model by CMG-Builder/IMEX 2010 simulator using an Iraqi fractured, faulted reservoir model. History matching has been carried out to improve the model which was going to be used in the simulation study. Several modifications were required during the history matching, such as adjusting the vertical fracture permeability, the relative permeability, the aquifer properties, setting fault transmissibility, and the matrix and fracture compressibilities. The results of the History matching showed excellent agreement between the simulation and the historical profile. Furthermore the recent validated data by history matching have been used for the Iraqi reservoir model by running the CMG/IMEX simulator.

Calibrating the Reservoir Model of the Garraf Oil Field

“…A numerical simulation analysis must provide the mathematical model with production/injection data (oil, water, and gas flow rates). Successful simulation research requires good-quality data in terms of direct input and reference data to assess the validity of the history match phase [5].…”

Methods Used to Estimate Reservoir Pressure Performance: A Review

“…Ali et al, 2015) conducted a simulation study for a reservoir with two hydrocarbon accumulations-Pay-one and Pay-two-with faults and natural fractures, using a black-oil three-phase, three-dimensional dual-porosity model CMG-Builder/IMEX 2010. The production is primarily from fractures for the first pay zone and fractures and matrix for the second pay zone, with active water drive, depletion, and water injection serving as the Field's primary derive mechanisms.…”