CO2 Injection in the nearly depleted K12-B North Sea gas field

Two different CO2 injection field tests were carried-out in the nearly depleted K12-B gasfield, offshore Netherlands, in different compartments. The CO2 originating from the produced gas (the methane contains a fraction of 13% CO2), is separated on the production platform and reinjected into the reservoir. The first test, completed in 2004, consisted of CO2 injection through a single well in a depleted reservoir compartment to test the injectivity. The second test is ongoing in a nearly depleted reservoir<br>compartment comprising two gas production wells and one CO2 injection well. This presentation describes the simulation results based on a detailed geological model and history match to the production data until December 2005. A highly accurate match has been obtained. In March 2005, two tracers have been added to the injected CO2 such that injected CO2 could be discriminated from resident CO2. Breakthrough of the tracers has been observed for both producing wells after 130 days (in 2005) and 463 days (in 2006). For the first well the simulation results for CO2 breakthrough have been compared to the tracer time. Results were accurate within a few days. For the second well the comparison has not yet been made since injection and production data were not available at the time of writing this abstract. This work is in progress.