Aberdeen-based Pragma Well Technology has developed an advanced retrofittable safety valve, which enables cable-deployed artificial lift technology, such as electric submersible pumps (ESPs), to be installed with added safety.
The “Slim Pump” Safety Valve (SPSV) recently achieved API 14A qualification to meet the highest safety standards and its unique features simplify its deployment and retrieval.
The SPSV is actuated by pressure differentials created by the ESP. This removes any reliance on the existing subsurface safety valve (SSSV) components and uses no pressurised chambers, hydraulic control lines or electrical power, improving reliability.
Greater use of cable-deployed ESPs using more efficient permanent magnetic motors (PMMs), benefits the industry by providing a more cost-effective, retrofittable and rigless solution to maximise production, both on and offshore.
When an existing ESP fails, operators can avoid the cost of a workover and lengthy downtime by retrofitting a slim-line cable-deployed ESP through the tubing, above the existing pump, stabbing into a seal bore packer set in the tubing. For depleted wells, or for reinstating shut-in wells that require artificial support to kick-start production, this through-tubing technology is fast and cost-efficient to install.
In many regions an API 14A qualified, subsurface safety valve (SSSV) is a legal requirement and most use a flapper style mechanism as part of the production tubing. However, a slim-line retrofitted ESP is deployed through the production tubing on conductor cable to provide power. This means that the ESP cable renders a standard SSSV inoperable, whereas Pragma’s SPSV avoids this issue as it is located below the ESP. Other regions have also adopted regulations which require greater well control for mature producing wells, so the SPSV provides an ideal solution.
SP series technology
The SPSV will fail-safe close when the ESP is switched off, and uplift pressure from above is low, and will open again when the ESP is pumping fluid to surface. It can be opened and closed as many times as required and provides an effective well barrier, being unaffected by lower well pressure. It effectively acts as a fluid loss valve, preventing PMM backspin for additional safety.
Providing added flexibility for operators, the valve can be deployed in a variety of configurations, either run in with the production packer, or with the ESP and latch, allowing regular field maintenance. As part of the SP series the SP latch prevents the tubing and ESP from pumping itself out of the sump packer when production starts.
Created using advanced materials and with the option for additive manufactured components, the SPSV provides a compact and cost-effective solution. It is available in variants for both 3.5” or 4.5” tubing with a standard temperature rating of 150 deg. C.
The unique bi-directional design permits a surface pressure test, to verify the integrity of the packer, valve and completion equipment. Emergency full bore pump-through is also available.
This versatile technology is multi-purpose and can be used as a safety valve for other artificial lift systems such as jet-pumps and velocity strings.
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