Egypt’s Waterflood Strategy Changes, Challenges, and Innovations

About thirty eight years ago, the first waterflood project in Egypt was initiated in El Morgan oil field located in the Gulf of Suez. Sequentially, more than 14 different waterflood projects have been implemented in the same area. The reservoirs that subjected for waterflooding have already produced a cumulative oil representing 40% of their original oil-in-place. On average, the projected waterflood recovery factor is 54% of their OOIP. Due to non-uniform lithology and non-uniform pattern of existing well locations in most reservoirs, peripheral waterflood was found to be the most suitable and economic waterflood pattern at project startup. As these reservoirs become more mature, the line-drive pattern (peripheral + internal injection) was found to be more effective. Seven years ago, a joint study integrating geological and engineering data was undertaken on some fields located in the western desert of Egypt. A detailed sequence-stratigraphic framework based on core description and petrophysical analysis provides the static reservoir framework for those reservoirs. These geologic data are incorporated in a detailed 3D geological model, which forms the basis for all structural and reservoir mapping. Pressure and production data were analyzed within this framework, in order to identify potential infill and recompletion opportunities as well as potential improvements in changing water-flood pattern from peripheral to internal and to dedicated injection. Since most of the reservoirs are currently in the mature stage, good managing and close monitoring for each waterflood project is extremely important. This paper provides major strategies in managing the different waterflood projects to maximize both the oil production rate and oil recovery in optimum manners. This is being achieved through several common and familiar waterflood issues including; in-fill drilling, zonal injection improvement, injection pattern modification, injection below formation parting pressure, pressure maintenance, workovers for production and injection wells, continuous data collection, and water quality monitoring. The paper also addresses the waterflood side effects of scale buildup, reservoir souring and facilities corrosion. In addition, it discusses some of the innovative techniques that have been used to maximize waterflood recovery and enable waterflooding of marginal fields.