Effects of formation damage on the productivity of horizontal wells

Horizontal wells are being developed throughout the world in an increasing fashion to increase production rates by maximizing reservoir exposure, targeting multiple zones, reducing drawdowns to minimize premature water or gas coning problems and exploit thin pay zones. However, in many cases where viable reservoir quality has been present, production results from many horizontal wells have been disappointing, and it is believed that, near wellbore formation damage effects have been a major contributor to this disappointing marginal flow performance. This research work examines the various causes of formation damage in horizontal wells, how the damage affects the well productivity in well configurations, with regard to changing reservoir properties and also with changing horizontal to vertical permeability ratios. It aims to determine the best horizontal well to drill in order to attain maximum production rate in these reservoir conditions.