At the PDO Nimr oil fields, only 10% of the production is crude oil. The other 90%, around 330,000 m³ per day, is water that is brought to the surface together with the oil. This water used to be disposed of by deep well injection. To reduce the high costs of reinjection and to enable beneficial reuses of the produced water, PDO decided to build a constructed wetland. The constructed wetland was originally designed to treat close to 200,000 m³ of produced water per day and has been successfully operating since 2010.
Optimisation of the water and CO2 footprint
A tool similar to AquaVest was used to optimize the water and CO2 footprint of the Nimr field facilities including the constructed wetland. A large number of scenario’s were run to explore different water and biomass monetization options including water reuse for biosaline agriculture and the application of RO to create drinking water quality water. High quality water is a valuable resource in a desert environment. The attractiveness of various investments options were evaluated based on NPV and VIR.
The business case
The study concluded that local market conditions, the proximity of local communities and farmland to the Nimr site and government policies related to water and CO2 accounting have a decisive influence on the economic viability of the plan.