Offshore Waste Water Management System Reduces Operating Costs

Abstract

Regulatory constraints governing the discharge of contaminated waste water in offshore operations are increasing across the world. In most regions, contaminant (oil) levels above 30 mg per liter are strictly monitored and regulated to protect our environment. These regulations prohibit disposal of contaminated material offshore, forcing this "slop" water to be transported from the rig to shore for proper treatment and/or disposal. The costs associated with transport, handling, and disposal are incremental to the drilling operations and drive up the cost of the well. These additional rig and logistical operations further expose rig personnel to potential health and safety risks by burdening the crew with additional activity and movement of materials. The intent of this paper is to show the performance capabilities of an innovative waste management system that has been proven capable of reducing the slop water volumes in offshore operations by as much as 80%.A novel waste management system has been developed and designed specifically to reduce the costs associated with offshore waste water management. The technology has been performance tested to prove that it can efficiently remove the contaminants required to allow clean permeate to be discharged to sea. Testing conducted to confirm system capabilities utilized genuine offshore slop water at various levels of contamination. Waste contents tested ranged between 1% and 10% and were comprised of both oil and solids.Performance testing has been successful for over one year with no visible suspended solids detected in the resulting permeate. All concentrations tested showed the quality of permeate produced to be below the 30 mg/liter oil in water threshold, qualifying it for discharge to sea. Additionally, the reliability and maintenance needs of the system were benchmarked to confirm operational efficiency and cost requirements.The system's performance has shown the ability to significantly reduce the volume of waste/slop water that would otherwise have to be transported to shore and treated/disposed of as prescribed by regulatory agencies. The system's ability to remove these contaminants directly results in reductions as high as 80% in the volumes being shipped to shore for treatment and disposal and consequently a significant reduction in disposal and handling costs.