Challenge: | KOC needed high-purity water for its oil field in a water-scarce region. The primary source, desalinated water, is expensive but draws on precious potable resources. |
Solution: | Aquatech devised a process to treat reject wastewater from Sulaibiya's municipal wastewater treatment & reclamation plant, which recycles sewage to a tertiary treatment level. |
Customer Benefit: | Quantity and quality requirements were met with economic viability and without utilizing potable water. |
The heavy oil found at Ratqa has a high viscosity and sluggish flow rate, causing KOC to require cyclic steam injection to extract the oil. This process uses ~300,000 barrels of water daily, which must meet specific quality standards.
WorleyParsons, the owner’s engineer, and Petrofac, the project EPC, collaborated with Aquatech to devise a process to treat the unique wastewater, which traveled from the Sulaibiya municipal WWT&RP. Due to extensive experience with recycling difficult-to-treat water, Aquatech could offer a solution that provides boiler feedwater that exceeds KOC’s needs and has low capital expenditure and operating costs.
The source water is challenging wastewater from Sulaibiya that contains a high scaling potential, organic contaminants, and high levels of total dissolved solids (TDS), total organic carbon (TOC), organics, and hardness. Aquatech implemented a highly water-efficient project to recover ultrafiltration (UF) and RO reject and produce high-quality boiler feedwater needed in high volumes. The UF and RO reject from the Sulaibiya municipal WWT&RP is treated with technologies such as lime softening, multi-media filtration, UF, ion exchange, high recovery RO, UV, and ozone.
Treating the water through ultrafiltration membranes removes any residual suspended solids, colloidal matter and high molecular weight organics in the feed water, achieving the low and consistent silt density index (SDI) required for RO operation. QUA’s Q-SEP ultrafiltration membranes provide superior quality and performance at a lower footprint and capital expenditure.
he subsequent high recovery RO consistently achieves 94% recovery, and the product water is subsequently treated by UV and ozone to remove any residual chemical oxygen demand (COD) and impurities. The final step of the scheme is Vacuum Degasification, which is required to achieve the Oxygen limit of <100 ppb in the final product water. This project utilizes Once Through Steam Generator (OTSG) boilers to produce the steam required to inject heavy oil wells. The solution produces 1,507 m3/hr (9 x 167 m3/hr) of high-quality ultrafiltration permeate, which is further treated in a two-pass reverse osmosis system to deliver high-quality permeate water, which is required for steam production for operations.
This water treatment plant has proven that achieving high recovery (~94%) even in an extremely challenging application is not a pipe dream but a reality and that high recovery reverse osmosis is a viable, sustainable and affordable technology that enables municipal wastewater to recycle and reuse to produce boiler feed water.
This successful commissioning of the 30 MLD wastewater recycle and reuse project for KOC’s Lower Fars oilfield represents a benchmark in sustainable water management. It has demonstrated that with sound design, including the appropriate experience, membrane technology (UF/RO) can be used to reclaim and recover every drop of water possible in a water-scarce region, thus preserving vital natural resources.
We are proud to be part of this landmark project. Aquatech’s long-standing track record in recycling difficult-to-treat waters has resulted in a solution to reliably recover water from waste and reduce carbon and water footprint. The need to maximize the use of unconventional water resources is growing, and this is a great example of how we can utilize technology and expertise to make every drop count.
Devesh Sharma, CEO, Aquatech