Shell Canada has conducted thermal recovery operations in the Peace River area of Alberta for over 50 years, using a combination of vertical, deviated and horizontal wells. During this time, many different recovery schemes, well designs, and operating practices have been used and assessed to determine the best approach to minimizing well integrity risk from safety, technical performance, and cost standpoints.
The cumulative experience has allowed Shell to have an in-depth understanding of the most appropriate casing and connections for specific thermal service that offer the best long-term performance and integrity. Casing cement design and placement practices are a key component in well construction to obtain superior, long-term, hydraulic isolation performance.
Well operations must be monitored though an effective surveillance process to obtain not only periodic assurance of mechanical integrity of well components, but also detection of inter-well formation anomalies that may lead to well failure or loss of hydraulic isolation if left unidentified.
Monitoring and observation wells can offer key additional insights on sub-surface events and changes, and instrumentation techniques can flag anomalies, as soon as detected, for further assessment and action. This can protect not only the wellbores in use, but also assess the effect of project operations on boundary areas and previously abandoned wells.