Re-Use of RO Reject in Oil Producing Facilities

In a gas plant, the reverse osmosis (RO) water treatment reject stream along with steam generating COGEN and auxiliary boilers blowdown are being diverted to the plant evaporation ponds for disposal. The facility has an adjacent oil producing plant with capabilities of handling sour water/produced water. The quality of the blowdown and reject are capable to be processed in the oil producing facility for well injection, use in seal flush systems, and oil desalting process rather than disposal in the ponds. A comprehensive water conservation assessment was conducted where multiple waste streams were identified and evaluated against alternatives destination and desired water quality. Following the assessment, the RO reject and steam generation blowdowns were rerouted to the adjacent oil facilities available capacity to process these streams and avoid consuming potable water in the oil facility operations. Frequent sampling was conducted to ensure consistent quality of the streams and avoid compromising the production of both plants, respectively. In terms of benefits and results, following the reroute, the evaporation ponds load during the winter was significantly reduced, and water consumption within the oil facility was also reduced from the potable water. The amount of water diverted, resulting in reduced fresh water consumption, was around 100 million gallons per year. In addition, no impact was observed on both facilities following the reroute. The initiative has been part of a comprehensive water conservation strategy in alignment with company and government goals.