Strategy Development to Address the Challenges of CO2 Storage in Depleted Gas-Condensate Carbonate Reservoirs. A Case Study from the Sajaa Field, U.A.E.

The Intergovernmental Panel on Climate Change (IPCC, 2022) states that both emissions mitigation and negative emissions efforts and technologies are required to limit average global warming to the 1.5°C projected scenario. CO2 geological storage is a negative emissions technology that is an enabler for direct air capture with CO2 storage (DACS) and bioenergy with carbon capture and storage (BECCS) (IEA, 2022) and tackles emissions in hard-to-abate sectors, such as the steel and cement industries. The International Energy Agency (IEA, 2023) estimates that sequestering 1.2 Gt of CO2 per annum by 2050 through carbon capture, utilisation and storage (CCUS) is required. Geological carbon capture and storage (CCS) will account for 95% of the sequestration (IEA, 2021), with 30 – 50% of that permanently stored in depleted oil and gas reservoirs (IPCC, 2005). The IEA (2023) states that only 45 Mt CO2 was captured in 2023. CCS projects with geological storage have concentrated on saline aquifers, such as the Quest and Northern Light projects, and in depleted fields with sandstone reservoirs, such as the Weyburn and In Salah projects. Despite their significant global potential, the focus on carbonate reservoirs and depleted gas-condensate fields has been low, reflecting in the limited amount of published material and knowledge sharing available.