Progress of CO2 Injection and Monitoring of the Tomakomai CCS Demonstration Project

Abstract

The Tomakomai CCS demonstration project is an offshore CCS project now under way in the busy port area of Tomakomai City, Hokkaido Prefecture, Japan. The Tomakomai Project is a nine-year project from JFY 2012(*) to 2020, comprised of a four-year construction, three-year CO2 injection and two-year post injection monitoring period. The CO2 source is offgas from a HPU (hydrogen production unit) of an oil refinery located in the coastal area of the Tomakomai Port. The gaseous CO2 captured by an activated amine process is compressed and injected by two highly deviated injection wells drilled from an onshore site targeting two offshore reservoirs, namely, the Lower Quaternary Moebetsu formation and the Miocene Takinoue formation. CO2 injection into the Moebetsu formation began in April 2016 and the cumulative amount of the injected CO2 is 206,632 tonnes as of 30th August 2018. Comprehensive offshore and onshore monitoring facilities comprised of three observation wells, an OBC, four OBSs and an onshore seismic station were deployed, and monitoring started in February 2015, thirteen months before the start of CO2 injection. Seasonal marine environmental surveys in line with a domestic law reflecting the London 1996 Protocol have been conducted along with CO2 injection. Since the start of CO2 injection, no seismicity has been detected at and around the reservoir. The first time-lapse 2D seismic survey was conducted from January to February 2017 at cumulative CO2 injection of about 7,200 tonnes into the Moebetsu formation, but did not show any anomaly in comparison to the baseline survey. The first time-lapse 3D seismic survey conducted from July to August 2017 at cumulative injection of 61,000 to 69,000 tonnes indicated a clear anomaly along the injection interval of the injection well for the Moebetsu formation. Prior to the end of the project, four further surveys; two 2D and one 3D seismic surveys are scheduled. (*JFY denotes April of calendar year to March of following year)

Keywords: GHGT-14; offshore; deviated injection well; micro seismicity; seismic survey; marine environmental survey; Tomakomai