CO2 underground storage for Snohvit gas field development

This paper presents an overview of the Snphihvit LNG project operated by Statoil and includes a description of the gas fields, the development concept, the production strategy and the LNG plant. The selected solution for the CO2 separated from the well stream, is storage in an underground structure. The technology for storage of CO2 in an underground structure is considered proven by the CO2 storage at the Sleipner field, Norway. However, the subsea concept and the lack of a huge water-bearing formation similar to the Utsira Formation in the Sleipner area resulted in challenges in establishing a prudent design for the Snphihvit CO2 injection system. This paper describes the reservoir selection process, the reservoir modelling as well as the CO2 injection facilities. The reservoir simulations described were performed by use of the Extended Network Option in Eclipse, which makes it possible to simulate the gas production from several well clusters combined with the CO2 injection. Further, the paper reviews the CO2 injection facilities including compression unit, pipeline, injection well and well control system from shore.