Innovative Remediation Techniques for Restoring Well Integrity by Curing High Annulus-B Pressure and Zonal Communication

摘要

The petroleum industry has made significant investments and extensive research to rectify well integrity issues, one particular failure mode relates to the migration of hydrocarbon fluids to surface through microchannels, due to poor cementation, resulting in the inability to provide integral barriers in the 95/8" casing x 12" hole annulus. Section milling and external casing patches are two of the widely-utilized approaches to restore annulus integrity; however, they add complexity associated with excessive steel cuttings and re-entry risk. Remediation using Hydra System is one of the innovative approaches that can be utilized in wells to provide strong integral cement barriers behind the 95/8" production casing below the 133/8" casing-shoe to prevent reservoir fluids migrating to surface. As a consequence, the well life can be extended and the older wells can be restored back to production and injection. This approach is gaining increased popularity due to a number of economic and environmental advantages such as restoring the well production/injection with minimum workover costs and risk due to less complex operations. The research utilizes a novel technology to execute a repair of wells with failed Annulus-B (95/8" x 133/8" casing annulus barrier) integrity by providing integral cement barriers in Annulus-B above the reservoir for wells experiencing migration of hydrocarbons from reservoir through the this casing annulus. The planned methodology starts with completion recovery followed by running noise, temperature and cement bond logs in order to evaluate the cement quality behind 95/8" casing above the reservoir.