Offshore CO2 Utilization: Sequestration, IOR, Blue Hydrogen and Ammonia

Summary Many IOR CO2 injection projects have been evaluated for possible application at the fields on the Norwegian Shelf: Volve field in the Sleipner area, main platform fields Gullfsaks, Statfjord and Troll in the North Sea, Draugen and Heidrun fields in the Norwegian Sea. None of these possible projects exploring CO2 IOR and geological sequestration synergies was finally considered economically feasible. A potential increase in oil recovery from miscible and immiscible CO2 injection was not evaluated as sufficient to compensate for additional costs associated with transportation /logistics, required additional processing and injection capacities. At the same time, CO2 geological sequestration projects at Sleipner and Snohvit fields were successfully implemented. Since 1996, about 1 million tons of CO2 from the Sleipner West natural gas is captured and stored in the Utsira aquifer reservoir 800 meters below the seabed in the North Sea. Natural gas from the Snøhvit field in the Barents Sea is transported through 143 km pipeline to Hammerfest LNG onshore plant since 2007 with about 0.7 million tons of CO2 from the processing plant being annually separated and returned to the field for injection into the aquifer. The CO2 sequestration project Longship represents a largest climate technology investment in Norwegian industry. In this project, CO2 will be captured from a cement factory, from flue gas at the waste incineration facility and the ammonia plant in Netherlands. CO2 will be transported by pipeline and ship to offshore storage site. From 2025 the first stage in the project will enable storing about 1.5 million tons of CO2 per year for 25 years. A possible second phase would have an estimated capacity of 5 million tons of CO2 per year. More and more blue ammonia and hydrogen projects are developed onshore. Hydrogen is regarded as a solution to decarbonize greenhouse gas emitting sectors of the economy. ExxonMobil announced the development of the largest low-carbon hydrogen production facility in Texas. It is planned to produce about 0.9 million tons of hydrogen and more than 1 million tons of blue ammonia annually from 2027–2028 while capturing and permanently storing more than 98% of the associated CO2 emissions. If hydrogen technologies can be developed for offshore application, many discovered stranded natural gas fields can become commercial with hydrogen and blue ammonia production on site. The paper will discuss what needs to be achieved to develop offshore SMR, separation and Haber processes facilities.