Independent global completions service specialists Tendeka has worked with design engineering and manufacturing company Wellvene to create and qualify a new version of its swellable sealing solution, SwellStack.
The introduction of the enhanced Tendeka/Wellvene SwellStack provides a cost-effective sealing solution that is compatible with all Wellvene and original equipment manufacturer (OEM) insert safety valves.
The use of the patented technology ensures production can be reinstated to wells that are closed in due to the failed sealing of an insert safety valve, thereby eliminating any requirement to consider higher cost and long lead straddles or potential workovers.
Downhole safety valve seal bores can become corroded or damaged due to intervention activity such as wireline. Standard chevron stacks commonly provided for insert safety valves may be unable to effectively seal within such damaged bores. This results in a leak path for hydrocarbons to migrate up the control line. In such cases the only solution is to perform a straddle installation or workover the upper completion and replace the damaged valve. Both options are costly and time consuming.
Originally launched by Tendeka in 2013, the SwellStack has been utilised in more than 180 installations globally prior to the release of the next generation design. Comprising of swellable O-ring technology and a bespoke chevron seal design, the swellable O-ring expansion within the damaged bore activates the chevron seals to both effectively and reliably provide integrity for up to 10,000 psi in liquid and gas.
Gillian King, Tendeka’s VP for Europe, Russia, CIS & Africa says, “Our partnership with Wellvene to develop this new, improved SwellStack brings a superior design to our clients for their mature fields. We have a proven track record using our SwellStack solution to bring shut-in wells back on-line, adding significant value to global operators whilst maximising economic recovery.”
Bronson Larkins, Managing Director at Wellvene adds, “Combining Tendeka’s patented swellable technology with our expertise in providing downhole safety valve solutions, has delivered a redesigned, re-qualified, and enhanced wireline retrievable downhole safety valve sealing solution.”
“With ageing well stock and high potential for damaged seal bores, I understand the challenges our customers are faced with regarding sealing integrity during safety valve operations. The newly improved and qualified version of the Swellstack shall provide greater integrity and operational efficiencies within the well intervention and integrity industry,” continues Wellvene.
SwellStack incorporates the knowledge gained from standard Tendeka swellable compounds which have been used in over 65,000 successful installations worldwide. Tendeka’s Swellable O-rings have been used since 2011, with more than 11,200 O-rings supplied globally to date. All O-rings are manufactured from an oil or water swellable compound, designed to swell when in contact with control line fluid or produced well fluids.