After a successful Offshore Europe, InnovOil caught up with John Flynn of Teledyne Oil & Gas to talk about how the firm’s subsea interconnect systems are enabling new deepwater developments
Although some of the most commonly used options for maintaining and enhancing oil recovery, the technology behind subsea boosting, pumping and processing still requires constant innovation. Done right, these systems can significantly enhance production with comparatively minimal CAPEX and OPEX. They are a valuable part of most enhanced oil recovery (EOR) operations, whether to help return hydrocarbons to topsides facilities or to inject water and/or additives into the reservoir.
As operators go deeper and more processes are moved to the sea floor, such equipment is becoming more and more necessary. The same efficiencies and advances made over the past few years mean that previously uneconomic marginal or brownfield sites may now be rejuvenated with new subsea facilities and tiebacks. Similarly using robust, modular systems ensure that OPEX is controlled and reduced. Reliable equipment is unlikely to fail, and maintenance intervals can be lengthened; when equipment does need repair or replacement it can also be done without major interruption to production.
Much of this equipment is now enabled to include monitoring and data-capture, meaning issues can be identified in real time, and operators can better plan their approach to asset integrity, flow assurance and maintenance.
Spanning all these trends, pressure on cost and on project timelines mean that operators are demanding that these projects are less expensive and more efficient. Recent years have seen a major push for greater standardisation, especially within the subsea sector, where a myriad of connectors, cables and pumps could be streamlined into far more cost-effective systems.
Even with technological advances, actually powering subsea equipment remains a major challenge. Teledyne Oil & Gas (TOG) understands this, having worked closely with the system integrators to power new and existing fields in extremely harsh deepwater conditions. The group provides reliable electrical interconnect to power subsea pumping and boosting equipment, as well as unique monitoring solutions as part of its Cormon line.
Its expertise in the former include electrical and fiber optic wet mate connectors, power connectors from 6kV to 15kV, electrical penetrators, and umbilical termination assemblies. It has also developed a number of new and custom products for bespoke projects, thanks to the work and expertise at its Daytona Beach Technology Development Center.
The Cormon range includes sensing and monitoring systems to detect corrosion and erosion rates via metal loss measurement. Cormon also offers sensors to measure pressure and temperature, either standalone, or integrated into corrosion and erosion probes. All of these help to enable better production efficiency by giving users access to real-time information and enabling them to make better decisions about when they should intervene.
In this way, TOG focuses on minimising the life cost of the product, and not just the upfront cost.
One of the major components of TOG’s subsea fleet is the Nautilus™ wet mate connector. The patented design was first developed in 1991 by an ocean scientist, and now over 110,000 connectors are in use across the oil and gas, ocean science, and defense sectors. Configurations include ROV, manual and stab, with ratings up to 250 Amps.
With a patented shuttle pin design, it offers exceptionally reliable multi-channel electrical connections. For added redundancy, it features dual independent seals and oil reservoirs; the pin enters these reservoirs before sealing via the shuttle pin and dual wiper seal assembly, simultaneously cleaning and sealing the pin and providing two completely separate barriers.
Most recently, TOG engineered a new line of 60-A Nautilus wet mate connectors for use in the North Sea. These are capable of handling more power than standard 30-amp models, and will be used to power the magnetic bearings in the new subsea gas compressors.
VP of global marketing communication for Teledyne Marine, John Flynn, comments that: “The major project challenges here were developing and qualifying new high temperature pins and bladders capable of operating above traditional Nautilus internal temperatures of 50°C.”
To achieve this requirement, the team adapted its standard Nautilus design by qualifying new higher temperature materials for bladders and boot seals. The result is a connector that operates at pressures of up to 4,350 psi in 10,000 feet of water. In the long term, this added engineering ensures the connectors are reliable and robust when in use subsea.
As has been noted, subsea developments are moving deeper and with longer tiebacks. Royal Dutch Shell’s Appomattox development in the Gulf of Mexico, approved in July of this year, for example, has a substantial subsea template in 7,200 feet of water. Big challenges are posed in terms of supplying power to this kind of infrastructure
Electrical penetrators are used in subsea systems to power boosting or submersible pumps at the seabed. The penetrator is exposed to high differential pressure, harsh pump fluids, temperatures of up between 35°F-250°F (1.6°C-121°C), and uninterrupted voltage of 10 kV during operation.
“The industry traditionally uses thermoplastic materials in penetrator designs. When dealing with high pressures and high temperatures, thermoplastics may not provide the required reliability,” Flynn says. Field operators at another Gulf of Mexico project approached TOG to research and design a penetrator system for horizontal ESP-seafloor pumping. This had to be capable of handling 250 A of current, and pressures up to 12,880 psi (inboard-to-seawater), meaning new materials would have to be used.
To devise a suitable penetrator, TOG assembled a cross-disciplinary team from both Teledyne ODI and Teledyne Scientific and Imaging (TS&I) to develop a design using ceramics, and incorporate a new copper conductor pin. “The team included representatives from mechanical engineering, moulding, reliability engineers, process engineers, and materials scientists,” Flynn explains. “We worked very closely with Teledyne Scientific, our research partner in Thousand Oaks, CA, to develop the ceramic components. The scientists have a history in helping design ceramic tiles for the space shuttle, among other components in the space program,” he adds.
The operating environments of space and deep sea have their similarities, he points out – “challenging environments, extreme temperatures, differential pressures, lack of access for repairs, expensive maintenance,” he says – and the team’s experience with materials was a major asset in choosing the right ceramics for the task.
In the final design, “The new penetrator pin enabled the penetrator to handle the thermal expansion of the copper conductor while the ceramic material withstands the extreme pressure.”
Custom boot seals were also designed and qualified to withstand the harsh pump fluids, and to provide the necessary electrical stress control for the high voltage electromagnetic fields.
Success with its 10 kV model has now led TOG to develop another, 15 kV model for deepwater work offshore Brazil.
“Every oil field has different operating conditions, and every customer has different interface requirements or specifications,” Flynn says. “But our strength is really to develop core technology, such as a ceramic penetrator, or reliable wet mate connector technology, and adapt it to our customer’s needs and to fit their specific applications.” Harnessing the expertise and resources of its talented team, there are few limits to the range of Teledyne Oil and Gas innovation.