An Eco-Friendly and Low Carbon Footprint Water Treatment Technology for Produced Water Recycling

Many challenges and limitations are experienced while treating the produced water in oil fields, due to large volumes of water produced together with oil. In this paper, we propose a new method to treat produced water, by integrating humidification and de-humidification desalination (HDH) unit with waste heat, extracted from abandoned oil and gas wells. This solution is based on circulating the produced water through abandoned wells (both vertical and horizontal wells) and heat them up to 60-80°C so that the heated water can be directly used as hot feed water into the HDH unit. This eliminates either electricity or power requirements from an external source thereby significantly lowering the energy requirements. The direct use of hot produced water at the desired temperature range allows for better performance of the HDH desalination unit, while reducing the operating cost, besides minimizing CO2 emissions to the environment. The use of heat extracted from abandoned oil and gas wells in the form of geothermal energy enables the utilization of waste heat associated with existing wells, which is already available in most of the oil fields. The proposed method therefore provides a sustainable renewable energy solution for produced water desalination using HDH processes.