Slim Pump Safety Valve successfully completes SIT with Zilift

DTI has successfully completed a systems integrations test on both size variants of its new Slim Pump Safety Valve (SPSV). This demonstrated the efficient and reliable operation of the SPSV under field simulated conditions, in advance of field deployment.

Our advanced SPSV technology is designed to be retrofitted to mature or depleted wells, in-line with a cable-deployed electric submersible pump (CDESP), to deliver enhanced operational safety.

The tests were conducted by Zilift at their purpose-built facility in Aberdeen, utilising a Zilift cable-deployed ESP in-line with the SPSV, within a test and validation flow loop. A range of tests were performed to ensure that both SPSV variants, a 2.625” and a 3.19” sized valve, functioned in synergy with the ESP. The SIT provides additional customer confidence and performance data and supports the product’s API 14A qualification, which was awarded in 2020.

Both valves opened within seconds of the ESP’s activation, ensuring no cavitation or overheating of the pump occurred. The valves quickly closed again on shut-down of the ESP. During continued operation, no impact in ESP performance was witnessed. Zilift personnel conducted pump-curve tests to fully validate the SPSV with their ESP technology. This work ensures the SPSV is fully prepared for commercial deployment in the North Sea and Middle East.

Operation

The SPSV sits below the ESP in the well and operates independently, removing any reliance on the existing subsurface safety valve (SSSV) components and uses no pressurised chambers, hydraulic control lines or electrical power, improving reliability. It is actuated by pressure differentials, to fail-safe close when the ESP is switched off and open again when the ESP is pumping. 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.

Applications

If an existing ESP fails, operators can avoid the cost of a workover and lengthy remediation downtime by retrofitting a slim-line cable-deployed ESP, along with an SPSV, 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.

Providing added flexibility for operators, the SPSV 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.

Design

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.