An Innovative Method of Water Management by Desalinating the Produced Water Using Thermal Renewable Energy

Produced water, which in many cases shows a high degree of salinity, is currently managed using water disposal wells and evaporation ponds. Both methods are conventional and have negative environmental impacts. ARA is adopting a unique and innovative method to manage high salinity produced water in an environmentally sustainable way by extracting potable water from produced water and reducing discharge water volume by at least 50%. For desalination of the produced water an innovative combination of forward and direct osmosis technology is used. This process is driven mostly by thermal energy which is provided to 100% solar thermal collectors. The structure of the plant is as follows: A solar thermal power plant consisting of 2 desert- and oilfield-proof solar thermal collectors ("HELIOtubes") with thermal energy storage (TES) using pressurized water for nighttime operations (24/7). The solar thermal plant powers an advanced forward osmosis desalination (FO) and brine concentration Direct Osmosis (DO) unit with pre-treatment unit to cope with the challenging produced water. This project is in the pipeline for implementation. The engineering and the planning design were successfully completed. Two main results are expected from this project, which is: (i) low-cost and low-maintenance thermal power and (ii) desalinated water from the produced water meeting the regulatory specifications. It is a state-of-the-art system integration engineering based on the simulation of the innovative desert-proof solar thermal plant including TES using 10-year historical satellite-based irradiation data to show optimal use of renewable energy. Lab studies show how low energy consumption pre-treatment of the challenging produced water with its difficult chemical composition can be achieved, allowing membrane-based forward osmosis to be applied even at a salinity level that is 3-times higher than seawater. That leads to high energy efficiency for desalination also at nighttime based on thermal power from cost-effective TES instead of expensive batteries. This system could be considered a game-changer in the oil and gas industry because it introduces a new water management methodology.