Search

Water Alternating Gas (WAG) injection is a Enhanced Oil Recovery method spread in several countries around the world since fifty years ago approximately. The technique consists in to inject inside a reservoir alternates and successive slugs of water and gas to achieve a best sweep efficiency of the interest zone; this fact will be seen reflected in an increase of the recovery factor. A description of the main theoretical aspects of this EOR process is presented, as well as a state of the art taking into account factors such as dominant displacement mechanisms, used gases, type of objective rocks and geographical location of the projects. Important operational issues during technique implementation are discussed. Finally, a screening guide to apply this EOR process, keeping in mind gathered information of historical field cases, is showed.