Xpandable steel AZIP completes pilot CCS well in the North Sea
Two Annular Zonal Isolation Packers withstand tough RIH and successfully isolate sand screen sections in a carbon capture and storage (CCS) pilot well.
Operators are now seeking to safely and permanently store the carbon under the seabed. The goal is to prevent CO₂ from reaching the atmosphere and aggravating global warming. Carbon Capture and Storage are part of the options available. The client was a leading pioneer in this technology. Local authorities approved injecting and capturing CO₂ permanently from onshore industries to more than 2,000 meters below the seabed. The well was an exploration test well to evaluate the CO₂ injection capacity into the Johansen aquifer. They needed to deploy 65/8in lower completion with sand screens between open hole packers. The packers would isolate unwanted sandy migrations through the annulus and seal in the 8.5in the open hole section. The client had to cope with difficult RIH and needed to reach the TD. As a result, the client selected Saltel Xpandable steel annular zonal isolation packer (AZIP). Saltel packers ensured they would reach TD with less risk of damage. There was indeed a high probability they’d have to work the string under predicted harsh RIH conditions.
Isolate sand screens in single-trip installation.
The client could not pressure up the whole string due to sand screens as part of the lower completion. Consequently, Schlumberger suggested an inner-string alternative with polished bore receptacles (PBR). The PBRs would act as locators above each Xpandable steel AZIP to ensure the pressure integrity at the packer’s level and secure the single-trip installation. Once at TD, the client pulled up, located the inner-string seal stinger in the PBR above the lower packer, then pressured up the inner string against the shoe to set the lower AZIP. They repeated the process and pressured up the upper AZIP after pulling up and locating the inner string seal stinger in the PBR below the upper open hole packer.