Multi Product Application on Gas Storage Well

A gas storage operator planned a major workover on one of its cavern wells to replace the existing completion and reinstate long-term injection and withdrawal capability. To safely access the cavern, deep-set plugs were required in combination with the Barrier Verification System (BVS) to isolate the lower wellbore. In addition, four extra barriers were needed to support the installation and retrieval of the new completion and to secure the well during rig-up and rig-down phases of both the wellhead and workover unit. The operator required multiple plug sizes and configurations to maintain full well integrity throughout the operation.

Interwell delivered a fully integrated multi-product solution combining Medium Expansion (ME) Retrievable Bridge Plugs (RBPs), High Expansion (HEX) RBPs, and the BVS to establish and maintain a complete barrier envelope throughout the gas storage cavern workover. Across the campaign, Interwell executed 29 separate runs, covering the installation and retrieval of plugs, junk baskets and barrier verification tools. 

Deep-set barriers were installed using the BVS, enabling real-time/memory verification of pressure and temperature between the primary barriers. This allowed the operator to continuously monitor cavern barrier integrity during critical phases of the operation. 

Additional ME and HEX plugs were deployed in the upper wellbore to support BOP removal, wellhead operations, and completion handling. The BVS provided continuous wireless readout of pressure and temperature, delivering live integrity data for all shallow set barriers while rigging up and down.

Junk baskets were run and retrieved as part of multiple runs to ensure a clean wellbore and protect barrier equipment during the extensive intervention. The majority of the plugs were set using Interwell’s Electronic Tool (EST), to assist in evaluating the setting prior to pressure testing. The coordinated use of ME, HEX, BVS, Hydraulic Running Tool (HRT) and EST technologies ensured full integrity verification across every phase of the 29-run program.

The multi-run operation was completed safely and efficiently, with 29 successful runs carried out to install and retrieve mechanical plugs, junk baskets and barrier verification tools. The plugs set using the EST generated clear digital setting signatures and were validated through pressure testing; providing the operator with robust mechanical integrity confirmation. 

The HEX plugs were retrieved using Interwell’s Electronic Pull and Stretch Tool (EPST), enabling clean engagement and controlled retrieval without damaging tubulars or downhole components. The combination of EST and EPST provided complete digital records for both installation and retrieval sequences. 

The BVS played a crucial role by delivering continuous wireless pressure and temperature data from shallow barriers. This ensured verified integrity of upper plugs while rigging up and down the BOP and wellhead; a phase typically associated with heightened operational risk. 

Junk baskets were set and retrieved as required throughout the programme, ensuring debris control and maintaining clean access for subsequent runs, contributing to the smooth execution of the entire workover. 

The campaign was completed without safety incidents or unplanned downtime. The operator benefited from a fully verified, multi-layered well barrier strategy that supported the entire completion changeout while maintaining the integrity of a critical gas storage asset.