Gas accumulator improves capabilities of subsea valve
Offshore staff
ABERDEEN, UK– Interventek will unveil what it claims is the world’s first subsea shear-and-seal safety valve powered by an integrated gas accumulator at the Subsea Expo show in Aberdeen.
This is a further development of the company’s Revolution valve technology, with a gas accumulator added within the valve, close to the cutting and sealing mechanism.
According to the company, it increases the power and speed of the valve’s functionality and provides a failsafe mode which is triggered in the event of an emergency.
The gas accumulator valve, named Revolution PowerPlus, is designed to provide a compact safety barrier within the BOP (and below the primary shear rams) during subsea well completion or intervention operations.
The valve should rapidly cut intervention media such as slickline, braided electric cable, coiled tubing or coiled tubing with braided electric cable, and seal the wellbore, containing pressure and allowing the intervention vessel to disconnect if needed.
Interventek also claims that the faster closing speed – less than one second – will improve safety, particularly during gas production, as the speed of closure and integrity of the seal directly affects the volume of gas that is prevented from escaping.
Traditional safety valves, the company says, operate at much slower rates and rely mainly on hydraulic fluid with a power source positioned further away from the cutting and sealing mechanism – typically above the BOP shear rams – which takes longer to activate.
The valve’s compactness allows it to be installed below the shear rams, even on small BOPs allowing the well to be contained without resorting to the shear rams which can be difficult and costly to remediate following activation.
A first prototype 6⅜-in.15,000-psi in-riser landing string Revolution PowerPlus model is currently undergoing cutting and sealing qualification tests. It employs a primary sealing rather than elastomer components which is said to allow safe well intervention in, for example, large wellbore, deepwater or HP/HT scenarios.
01/28/2019
