A Lasting Connection: Mining
The mining, oil and gas industries see workers and equipment deployed into some of the most inhospitable locations on Earth. From the frozen wastes of the Arctic circle to the unforgiving heat and humidity of the jungle, the quest for energy has taken us to the ends of the Earth.
Designing and manufacturing equipment that will continue to work in these demanding conditions requires components that can provide a high level of reliability and protection.
The increasing sophistication of electronic systems and their deployment in these harsh environments has forced connector manufacturers to develop new solutions.
The offshore environment presents a range of hazards. Above the surface, the impact of wind and waves can result in considerable physical damage while the corrosive nature of salt water weakens the exposed metal.
However, equipment deployed below the surface must face one of the most challenging environments known to engineering: the massive external pressure caused by deep water.
During the descent to the seafloor, the pressure increases by the equivalent of one atmosphere for every 10 meters of water. Therefore, at 1000 meters, the external pressure is approximately 100 times more than that experienced on the surface.
This deep-water environment is crucial in our quest for resources, but the pressures found at depths of 200 meters or more prevent the use of human divers. To solve this problem, the oil, gas, and mining industries rely on remotely operated vehicles (ROVs).
ROVs are crewless submarines that are designed and equipped to survive the crushing pressures found near the seabed. They are controlled by a pilot on the surface using imagery collected by the ROV.
ROVs are capable of more than just exploration. Larger versions can be equipped with arms and tools, allowing them to conduct complex operations like repair and maintenance, even at huge depths.
Understanding the Requirement
Unlike true submarines, ROVs are generally not free-swimming. Instead, they depend on a large cable known as a tether to provide a link to the surface.
The tether provides all power and control services required by the vehicle. For modern vehicles, fiber optic cables are often included to accommodate the volume of data that is collected by onboard systems.
One ROV operator found that the tether attachment point was also the source of considerable delay and cost. The tether was hard-wired onto the ROV, with many power and signal lines to be connected, along with a fiber optic link.
The operator was forced to conduct hours of maintenance after every mission, and the time taken to reattach the tether in preparation for the next deployment was costing more than $100,000.
The client approached Bulgin to design a new connector solution that could provide all the electrical and data services to the ROV. By building these links into a connector, the servicing of the ROV between missions would be far quicker.
The conditions encountered by the client’s mission were extreme.
The tether cable was just under 127 mm (5 inches) in diameter. The connector it would be fitted into needed to remain sealed at depths of up to 7000 meters (20,000 feet).
The temperature and pressure encountered at this depth allowed no room for compromise when choosing materials; Bulgin selected grade 316 stainless steel for the body of the connector itself.
The external pressure of over 700 atmospheres (10,000 psi) had also forced the operator into an unusual approach for the cable design, presenting an additional challenge.
To prevent the cable from being crushed, the empty cavities were filled with non-conductive, dielectric oil. The tether connector needed to accommodate a corresponding tube to allow the pressure to be equalized on either side of the attachment point.
Creating the Solution
The engineering team at Bulgin is experienced in creating sealed connectors for some of the harshest environments. They used this expertise to create the Bulgin ROV Tether Connector.
With a screw-locking system for secure mating, the ROV Tether Connector is a hybrid solution that delivers the power of 5 KV at 32 Amps to the vehicle, along with conventional data circuits and dedicated fiber optics.
It incorporates the all-important Pressure Balanced Oil Filled (PBOF) system that prevents crushing at enormous depths. The high-grade stainless-steel shell provides the strength needed.
With the ROV Tether Connector, lengthy installation is no longer needed, reducing the cost for each mission. The solution is repeatable, allowing the operator to minimize preparation and make the best use of the time available.
The client worked with the Bulgin engineering team at all stages of the design process. The initial concept was developed by Bulgin over 6 weeks, providing the client with full documentation and a non-functional 3D model for their evaluation.
Following approval, Bulgin was able to create a functional prototype in another 6 weeks.
In just over 3 months, the client had a fully customized, production-ready tether connector that saved hundreds of thousands of dollars over the life of the ROV.
The ocean will become more important over the next few decades, as we look to the sea as a source of raw materials, food, and energy.
Bulgin is ideally placed to support the exploration of this vast environment, developing bespoke solutions that will provide reliable service in the harshest conditions. Contact us to learn more.