Objectives
- Identify the relevant technical issues
- Propose a conceptual CO2 injection completion
- Identify operational scope, risks and issues
- Recommend a work unit
- Develop an operational time estimate
Method
- Reviewed existing well status
- Proposed a CRA liner / CRA completion
- Reviewed design cases and identified test pressure for casings
- Constructed time models, listed key risks and contingency time provisions
- Recommended a light rig with power swivel
Challenges
- Condition of existing wellhead, wellhead specification break for CO2 injection
- Mitigation of ongoing aquifer cross flow risks in sand-prone overburden
- Mitigation of risk of external carbonic acid corrosion on existing carbon steel production casing above the production packer
- Derated casing burst capacity based on metal thickness logs
- Annulus fluid freezing during CO2 injection transient events
- Balancing production casing burst risks versus design life of injector
- Phasing of work to resolve key uncertainties at minimum committed cost
Outcomes
- Concept level definition of workover scope, operational plan, times and risks
- Framed further assessment of the balance between casing condition and burst capacity versus CO2 injection life
- Framed initial mitigation strategies for key CO2 injection operations issues
