Sustainable Utilization of Zero Liquid Discharge Produced Water Treatment Waste in Lost Circulation Applications

In the process of oil and gas explorations, crude is being produced from subsurface reservoirs. Crude is a mixture of hydrocarbon resources such as oil and gas along with water. The mixture is then sent to gas oil separating plant (GOSP) where oil, gas, water and other impurities get removed and/or separated. Suitable treatment and handling technologies of produced water for proper recycling and reuse is gaining traction within oil and gas industries. Zero liquid discharge (ZLD) technology developed exclusively for desalination of produced water generates low saline clean water from hypersaline produced water with recovery efficiency from 80 to 90%. The small quantity of excessively salt laden reject waste stream is generated as a byproduct from ZLD desalination plant. As the waste water is saturated with salts, it is not fit to reuse for many domains unless treated appropriately. Finding use for reject waste water to reuse without further treatment such as recovery of different minerals or any drilling applications is ideal to accomplish 100% circular economy. In this paper, we studied the applicability of waste water for potential reuse in drilling applications as carrier fluid to prepare lost circulation slurry and compared the performance with lost circulation slurry prepared using regular drill water. We have also investigated the applicability of ZLD reject brine as an internal phase of formulating invert emulsion oil based mud. This is to promote sustainability to reuse the waste water and to circumvent waste discarding.