By Scott Parker, Product Manager for energy chain systems in Canada, igus
Mining industry rigs rely on service loops as the heart of their operations. The loops include cables for electricity, hydraulics, and pneumatics, and need to work in all types of weather and conditions. If there is a hiccup in the heartbeat, whether it is for maintenance, replacement or failure, the rig needs to be shut down, resulting in lost time and revenue.
Most service loops, however, require frequent maintenance and replacement. The process is expensive, time-consuming and frequent. Many cables need to be replaced after just two years. Weather can also impact service loops. High winds can cause cables to become snagged on the rig frame, resulting in rips or pulls.
AKITA Drilling in Canada frequently faced difficult weather conditions and production delays. The company sought a new solution for its 500,000 lb capacity pad drilling triple rig, and in January implemented a long-term answer. The day prior to one of Saskatchewan’s worst blizzards of the winter, workers retrofitted the rig with an energy chain. AKITA, which was drilling for potash for its customer, K+S Potash Canada, teamed with igus in an 8-hour retrofit of the rig with a 21.5 meter energy chain.
Winds reached 88 mph the next day in Regina, where the rig is located. The storm brought 6 in. of snow, and temperatures fell to nearly –40°. Residents reported numerous power outages. Under these circumstances prior to the retrofit, workers had to suspend operations.
This time, however, the rig with the igus energy chain rolled on in the cold Canadian night. No snags, no work stoppages, no unplanned downtime. The e-chain serving as the service loop for the rig aced its first test with flying colors. The rig’s steady pulse remained unaffected amid the worst conditions possible.
“Even in those extreme conditions the loop functions very well,’’ said Darren Hrynkiw, a senior manager for K&S. “I am always pleased when an engineered solution can be found to eliminate a safety hazard as this is far more effective than procedural safeguards. We expect little to no maintenance given its design and there are no productivity impacts with the installation of this protective system.”
Any drilling rig becomes inoperable without reliable service loops. The loops power a large electrical drilling motor that is installed in a derrick, which supplies the torque to turn the drill string. The system allows the drill to reach depths as far as 10 kilometers. Electrical service loops provide the power to the main motor and auxiliary power for other functions, such as lighting, lube oil heaters, and cooling fans. They also power control, data and instrumentation functions.
Most service loops, however, are made with steel, and require steady maintenance. In addition, steel loops are susceptible to corrosion. Repair work on rigs is quite dangerous, with all sorts of moving parts and components and the possibility of flammable chemicals or natural gas or oil in the well. The deadliest rig incident occurred in 1988, when 167 workers were killed at the Piper Alpha oil platform in the North Sea. Only 61 workers survived the tragedy.
AKITA’s rig included wrapped cables, but they became snagged when they came close to the rig frame. That caused rips and pulls on the cables, which are also costly to replace.
“Sometimes the wind gusts and grabs the service loop and sends it into mast beams,’’ said Justin Amyotte, a Field Superintendent with AKITA. “Hopefully, the driller sees it and stops and fixes the snag. If he does not see it, the cords get damaged. That results in even longer downtime.”
There were also safety concerns. “There was more than one occasion where the service loop became snagged on the top drive, resulting in a dangerous overhead safety incident with high voltage cabling,’’ Hrynkiw said. “Multiple engineered safety solutions were explored, but in most cases the solution presented other maintenance or sometimes even new safety concerns.”
Eliminates snags, safer repairs
The e-loop from igus has a bend radius of 500 mm, and includes a protective cable guidance system that eliminates service loop cable snags and hang-ups. The modular design allows easy pre- and post-installation access, making it safer for repairs. igus manufactures highly technical, cost down products that are self-lubricating and extraordinarily durable.
“Less down time results in more productivity, and less damage to the rig saves money,’’ Amyotte said. “There is also an important safety component. There is 600 Vac running through those power cords and up to 600 A before the breaker trips.”
The product combines the advantages of a polymer energy chain with a Dyneema rope that possesses high tensile strength. The tensile forces are absorbed by the rope and passed through the mounting brackets into the support structure. The design relieves cables of any strain, and ensures a defined bend radius of the cables. The modular e-loop also withstands vibrations and shocks.
The e-loop is mounted in the middle of the mast, which is a load-bearing structure used to support and position the drill string. The e-loop traverses the 136-ft mast by going 70 ft up and 70 ft down from the center point.
Applicable for all rigs
While the technology in this application was used for potash, Amyotte said any rig could use the technology. “A drilling rig is a drilling rig,’’ he said. “What it drills for doesn’t matter. It could be a huge benefit on any drilling rig.”
Canada is the world’s largest producer and exporter of potash, which is an important ingredient in fertilizer. It supports plant growth, yield and enhances water preservation. Potash is a group of minerals and chemicals containing potassium, and is added to farming soils in large amounts for high crop production. Ninety-five percent of the world’s potash is used in farming to fertilize food supply.
It is also critical to the Canadian economy. Exports of potash from Saskatchewan amounted to more than $5 billion in 2017, and generated payments of more than $308 million to the province’s economy in 2017-18.
The economic figures illustrate the importance of keeping the rigs operational, no matter the weather.
“We worked out a great solution,’’ Amyotte said. “This has been a challenge for us for a while, so it’s nice to have something we can depend on.”