Waterflood Strategy, Challenges and Innovations

Abstract More than twenty four years ago, Gupco (Gulf of Suez Petroleum Company) initiated the first waterflood project in Egypt for the giant El Morgan oil field. With continuing waterflooding experience, Gupco has applied this improved recovery method for other fields. Currently Gupco operates 14 different waterflood reservoirs. These reservoirs have produced a cumulative oil representing 40% of their original oil-in-place. On average, the projected waterflood recovery factor is 54% of 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. Peripheral waterflooding has the advantage that it minimizes the number of injection wells by converting the watered-out producers. As the Gupco reservoirs become more mature, the line-drive pattern (peripheral + up-dip injection) was found to be more effective. Since most of the Gupco's reservoirs are currently in the mature stage, good managing and close monitoring for each waterflood project is extremely important. This paper presents Gupco strategy 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: a) pressure maintenance, b) in-fill drilling, c) zonal injection improvement, d) injection pattern modification, e) injection below formation parting pressure, f) workovers for production and injection wells, g) continuous data collection, and h) water quality monitoring. The paper also shows how Gupco is addressing the waterflood side effects of scale buildup, reservoir souring and facilities corrosion. In addition, the paper discusses some of the innovative techniques that Gupco has used to maximize waterflood recovery and enable waterflooding of marginal fields. Examples for these techniques are gas-cap water barrier injection, heavy oil waterflooding, coiled-tube water injection lines, slim-tube dual completions, and satellite waterflooding for pilot and marginal fields waterflooding.