Aberdeen-based oil and gas production technology business Pragma said it has developed an advanced downhole safety valve to create an improved well control solution for cable deployed electric submersible pumps (ESPs) retrofitted to production wells.
According to the company, the new valve will enable on and offshore installations to meet all safety regulations whilst improving the operational footprint at the wellsite during installation and retrieval by reducing time, cost, personnel and risk.
An API 14A qualified subsurface safety valve (SSSV) is a legal requirement for producing wells in many regions. These devices generally use a flapper style mechanism and are incorporated in the production tubing during completion. However, when an ESP is retrofitted to a well, its surface control lines run through the inside of the production tubing, obstructing the SSSVs and creating the requirement for an additional safety valve. A rig would usually be mobilised to deploy the valve and then the ESP in separate runs, however cable deployment now provides significant cost and efficiency savings. Pragma explains.
Pragma’s ESP safety valve has been designed to complement this type of deployment. It is integrated within the lower portion of the ESP assembly and is deployed and retrieved through the production tubing in the same run as the ESP. It is said to be the only device on the market which offers wellbore closure below the ESP control lines. By installing the valve between the ESP and ESP packer, the valve does not rely on the integrity of aged well completion components unlike alternative systems.
The valve’s functionality is based on a novel pressure differential, or lift actuated design, requiring no pressurised chambers, hydraulic control lines or electrical power, which safeguards reliability. The valve will fail-safe close when the ESP is switched off and can be opened and closed as many times as required. The technology can also be applied to alternative artificial lift systems including capillary strings, gas lift velocity strings, progressive cavity pump and jet pump systems. A high temperature version is also available, the company noted.
Pragma technology manager, Matt Manning , said: “ Like a demand valve, or pressure regulator between the tank and mouthpiece of deep-sea diving equipment, our valve uses the ESP’s lifting capability to open or close it in line with production. The unique design advantages of this technology, combined with its compact nature, not only provide greater safety and reliability assurances to the operator, but also lower installation, operation and retrieval costs. The technology has been developed in-house and we are conducting prototype testing, with field trials and API 14A certification planned later this year.
“As the oil and gas industry continues to evolve, it’s important the supply chain also adapts to deliver quality solutions to support cost reduction and production optimisation. The ESP safety valve is just one example of how Pragma continues to pioneer advanced technologies to deliver safety and efficiency gains .”