Global completions service specialist Tendeka has worked with design engineering and manufacturing company Wellvene to create and qualify a new version of its swellable sealing solution, SwellStack.
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 these 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.
The patented technology provides a cost-effective sealing solution, compatible with all Wellvene and original equipment manufacturer (OEM) insert safety valves. It ensures production can be reinstated to wells that are closed in due to the failed sealing of an insert safety valve, eliminating any requirement to consider higher-cost and long-lead straddles or workovers.
Originally launched by Tendeka in 2013, SwellStack has been used in more than 180 installations globally prior to the release of this next-generation design. Comprising of swellable O-ring technology and a bespoke chevron seal design, the O-ring expansion within the damaged bore activates the seals to both provide integrity for up to 10,000psi in liquid and gas.
Tendeka VP for Europe, Russia, CIS & Africa, Gillian King, said: “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.”
Wellvene managing director Bronson Larkins added: “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.”