Beneficial reuse of produced water

Location: Nimr oil fields, Oman

Customer

Petroleum Development Oman LLC (PDO): a joint venture between The Shell Petroleum Company Ltd and the Government of Oman

Introduction

At the PDO Nimr oil fields, only 10% of the total 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 re-injecting the produced water, and to explore beneficial reuses of the produced water, PDO decided to build a constructed wetland that polishes the water to a quality that is suitable for biosaline agriculture. 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.

AquaVest for improved NPV and higher impact

The AquaVest algorithm was used to optimize the water, power and CO2 balance of the Nimr field facilities while minimizing TCoO. A large number of scenarios were focused on optimizing the design of the wetland system and on better understanding the different water and biomass monetization options. Different water purification and distribution options were explored including the application of RO to create drinking quality water. Drinking quality water is a valuable resource in a desert environment. The attractiveness of various investments were evaluated based on NPV and VIR.

The study concludes that local market conditions (supply versus demand), the proximity of local communities to the Nimr site and government policies related to environmental penalties heavily influence the economics of the different options.

Impact

SDG12: Responsible consumption and production

  • Beneficial water reuse (produced water is treated as a resource, not as a waste)
  • The effluent can be reused for biosaline agriculture or can be upgraded to drinking quality water

SDG13: Climate action

  • The creation of an ecosystem within a desert environment
  • The new ecosystem improves climate regulation and leads to better soil, water, and air quality

SDG15: Life on land

  • The project is an example of how to “green the desert”
  • The wetland increases biodiversity (more then 100 bird species detected)