LOCAL EXPANSION IS A SIMPLE WAY TO SEAL MICRO-ANNULI AND STOP UNWANTED GAS FLOW. THIS ONE-RUN TOOL LEVERAGES A TELESCOPING CONE THAT EXPANDS A RADIAL SET OF HARDENED KNUCKLE-BENT FINGERS INTO THE CASING.

The solution involves a new process that uses a retractable, expandable mechanical device to cause plastic deformation and elongation of the casing string’s inner diameter. This leads to the casing’s outer diameter expanding into the cement. The resulting reduction in the annular volume seals off the micro-annuli defects in the cement and results in a densification of the cement overall. This approach allows for rigless remediation of annular gas/fluid migration.

Shell developed this process, which permanently deforms the casing pipe to increase its local diameter. It operates mechanically, with full control, and can be repeated quickly at any target interval. This engineered redundancy ensures the complete elimination of all micro-annuli and backside gas flow issues with confidence.

HOW IT WORKS

THE LOCAL EXPANDER™ FUNCTIONS BY ENLARGING THE CASING INTERNALLY, IN EFFECT COMPRESSING THE SURROUNDING CEMENT. 

• Fingers at the top end of the tool are pressed outward by an actuated cone. 
• The fingers expand the casing into the cement. 
• RESULT: The cement is locally densified, and any gaps or small channels are sealed.  

CONVEYED VIA ELECTRIC WIRELINE 

The Local Expander places a sequence of crimps in the casing, eliminating the micro-annulus. This tool, which can be used in a single run and is conveyed via an electric line, has delivered comparable results to the traditional squeeze methods, albeit more cost-effectively and efficiently.

SAFETY 

The Local Expander also significantly increases safety in workover operations. With the casing crimped near the surface, the personnel can operate under safer conditions, confident in the knowledge that there’s no gas leakage to the surface.

PLUG AND ABANDON 

Wells scheduled to be permanently taken out of service must be totally sealed not only at the surface but throughout the casing string. This means no leaks of any kind. This often results in a backlog of wells waiting for plug and abandonment. The Local Expander is the trusted choice for scheduled plug and abandonment because it can affordably seal any leaks prior to plug and abandonment. Once gas migration leaks are sealed, plug and abandonment can proceed.  

Wells marked for permanent decommissioning must be entirely sealed both at the surface and throughout the casing string, ensuring zero leakage. This requirement often causes a queue of wells awaiting plug and abandonment. The Local Expander is the go-to solution for scheduled plug and abandonment because of its ability to cost-effectively seal all leaks before discontinuation. Once gas migration leaks are sealed, plug and abandonment can proceed.

In addition to plug and abandonment, several other wellsite operations can utilize the benefits of the Local Expander. 

• Shutting off backside pressure in producing or injection wells 
• Stopping gas migration behind the surface and/or intermediate casing strings during the drilling process 
• Preventative maintenance prior to hydraulic fracturing where the Local Expander is used to isolate the frac zone  
• Create a barrier during squeeze cementing

REGULATORY

The Local Expander is the preferred solution for regulatory departments because it repairs micro annulus without the use of chemicals and perforation. RWLS Specialty Services is working with the Regulatory bodies in Western Canada, Saskatchewan, Alberta and British Columbia, to name a few, to advocate the importance of eliminating this type of issue by finding a means to mitigate stray gas migration from the beginning.

ENVIRONMENTAL

Because there are no explosives, permanently deployable tools, products, or chemicals left behind, the Local Expander leads the industry in an alternative service that leaves no trace beyond the intended service. Furthermore, keeping unwanted gases and liquids in the ground instead of permeating to the surface on the backside of the casing has always been the preferred choice.