(Credit: Saudi Aramco)
[Editor’s note: Saudi Aramco is a winner of an Environment + Energy Leader Project of the Year Award. The E+E Awards program is accepting submissions for 2021. Submission deadline is February 19. Submit here.]
Saudi Arabian national petroleum and natural gas company Saudi Aramco said that water reservoirs far from the Gulf previously required significant quantities of non-potable groundwater for injection to help produce oil. In 1979, the company created a Sea Water Injection Department (SWID) to replace most withdrawals from this source. Since then, the department has been conducting annual projects to avoid consuming non-potable groundwater while reducing energy consumption and cutting GHG emissions.
Saudi Aramco founded SWID by commissioning the Qurayyah Sea Water Plant (QSWP) and an associated pipeline network. The company gradually replaced the requirement for non-potable groundwater with a series of expansions to the plant from 5.5 million barrels per day (MMBD) in 1978 to 7.0 MMBD in 1994 to 9.5 MMBD in 2005 and then to 14 MMBD in 2008. QSWP, however, consumes groundwater for utility and potable uses to avoid energy consumption for desalination as well as GHG emissions.
In 2019, SWID implemented three initiatives. QSWP shifted from continuous groundwater treatment to need-based intermittent operation, resulting in saving 64 million gallons. SWID also optimized the use of gas turbines to inject that seawater, resulting in 13,770 million SCF fuel gas consumption avoidance, and enhanced efficiency of pumps — among other equipment — to avoid over 100,000 MWh power consumption, Saudi Aramco said.
The company has a water treatment strategy map for annual projects that enables reductions in non-potable groundwater, energy, and GHG emissions. In 2019, Saudi Aramco implemented sulfate-removing facilities that make seawater compatible with more reservoirs, helping avert withdrawals of non-potable groundwater for pressure maintenance. The facilities use nanofilters that previously experienced flux loss due to the biocide chemicals that protect SWID’s pipelines from corrosion and leaks. Last year plant personnel collaborated with biocide service providers to formulate the first biocide mixtures compatible with membranes to protect pipelines over the long run.
QSWP’s cumulative maximum design treatment amounts to nearly 21,000 million cubic meters, according to Saudi Aramco. This non-potable groundwater savings equals more than 650 years supply of 2 liters of daily water intake for the current Saudi population, and around 15% of available groundwater in Saudi Arabia’s largest aquifer, the company said. The present design treatment capacity achieves as much as 812 million cubic meters annual groundwater avoidance. By comparison, the country’s total non-renewable groundwater withdrawals for the industry was 800 million cubic meters in 2016. SWID’s groundwater avoidance in 2019 represented a 55% drop from 2018.