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SwellStack Overview

SwellStack overview

Tendeka has the in-house capability to custom design a range of sealing solutions, from non-standard diameters to unique fluid parameters, ensuring the end result is a perfect fit for well projects. SwellStack is designed to seal inside damaged and corroded seal bores within downhole safety valves, restoring production and maintaining well integrity.

The Challenge
Due to intervention techniques, downhole safety valves can become corroded or damaged due to wireline activity. Standard chevron stacks commonly provided with safety valves are unable to seal in this damage and prevent any leak that can lead to hydrocarbons migrating up the control line. Prior to Tendeka’s development of the SwellStack, a patented technology, the only option of a leaking safety valve was to perform a straddle or workover, and replace the damaged valve. This proved to be costly and time consuming.

Tendeka’s sealing solution
In 2013, Tendeka developed and released SwellStack, a swellable sealing solution which can be installed on an insert safety valve in place of an existing chevron stack, to seal in any damage in the bore and successfully withstand the required pressure of the existing DHSV.

Originally designed for a major North Sea operator whose leaking safety valve resulted in the well being shut in, the SwellStack solution has since been used with multiple operators globally to regain the integrity of downhole safety valves. Comprising of a swellable seal element, and multiple chevron seals, the swellable element seals any damage in the seal bore and activates the chevron seals, effectively providing a seal.

Easy to install with no further intervention required, the SwellStack can be used in damaged bores of up to 0.063”, maintaining a continuous working pressure of 5000psi to successfully regain well production.

SwellStack Overview 2019