CETP - Quantitative Strain Monitoring for Well and Seal Integrity through Wellbore Fibre Optics Cables

To assess the formation integrity, the temperature, strain and acoustics recorded in well environment will need to be corrected 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 may 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 barriers to implementation that prohibit exploiting downhole (inside- or outside-casing) FOC data in CO2 storage projects. This technology proof will 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 geologic surprises.

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.