ENERGIFORSKNING-ENERGIFORSKNING

To assess the formation integrity, the temperature, strain and acoustics recorded along well environment need to be analyzed further for the coupled strains and acoustics through multiple media (formation, cement, casing steel, fluid, tubing) and the injection operation. Such in-situ multi-physical behaviour may not be captured and understood by single-point measurement such as bottom hole pressure and temperature (BHP and BHT). Fibre optic cable (FOC) sensing can provide a promising solution to this barrier. Q-Fibre aims to provide a technology proof to reveal the added value of downhole applications of FOC data for the purpose of quantitative characterization and monitoring of CO2 storage integrity, and eventually to reduce the technical and regulatory barriers to implementation that prohibit exploiting downhole (particularly, outside-casing) FOC data acquisition in the North Sea. This technology proof will also trigger a solid business model for FOC data acquisition along well and ensure that safe CO2 storage be viable with optimal operation cost and minimal geological surprises. During the first year of Q-Fibre, we have started setting up a preliminary version look-up table where we identify and summarize critical events that are realistically detectable via fibre optic cable data along injection or monitoring wells. This preliminary-version look-up table will guide all Q-Fibre WP tasks so that Q-Fibre can efficiently achieve the goals promised in the proposal. In this course, it was essential that the research and industry partners closely communicate and execute tasks together. In addition, all WPs in Q-Fibre progress according to the plan suggested in the proposal without much modification, including regular meetings among each WP members.

The main motivation is to build extensive novel knowledge on fibre optic cable (FOC) data and to enable safe CO2 injection via quantitative characterization of subsurface integrity, covering coupled interaction among pressure, temperature and fluid movement. Our aim in Q-Fibre is to contribute to FOC data processing and interpretation with the link to the coupled thermo-hydro-mechanical behaviour between the various elements in the near-well configuration, and to quantitatively understand near-well formation behaviour for early warning of subsurface integrity. It involves feasibility of using FOC data for integrity assessment of an entire sealing system for CO2 storage, including: a) caprock and secondary seals; b) both onshore and offshore; c) observation and injection wells. Eventually, we will also reduce uncertainty for the limits of integrity.