Cold CO2 injection in depleted gas fields: coupling of wellbore and reservoir
conference paper
In the North Sea CO2 injection is planned into many depleted gas fields. CO2 will arrive at the platform at ambient temperatures of around 5-10°C. Injection at this temperature can result in sub zero temperatures in the well due to flashing of the CO2 at the well head choke, leading to pressure and temperature coupled at the phase boundary. This two-phase flow can persist in the reservoir. To understand where and how long two-phase flow and low temperatures occur, a steady state in house wellbore simulator is coupled to a commercial reservoir simulation model. Both reservoir and wellbore model solve the flow based on pressure and enthalpy, leading to greater numerical stability for fluids with a narrow phase envelope. The models are coupled via the bottomhole enthalpy. The results show strong variations in injectivity of the well due to different phase conditions, which cannot be captured with a wellbore model only. The downhole temperature strongly depends on the pressure in the storage reservoir.
TNO Identifier
994411
Source title
4th EAGE Global Energy Transition Conference and Exhibition, GET 2023
Pages
1-5
Files
To receive the publication files, please send an e-mail request to TNO Repository.