Enhanced control during installation projects.
Subsea piling can be complex and technically demanding; operations often require a high level of skill and experience to deliver what customers need. CIS understands the challenges of subsea piling projects and has developed its new remotely operated subsea piling system to address these issues. The system, which the company designed for driving of piles up to 36-in. in diameter in water depths to 300 m plus, was used for the first time on a major installation contract for Technip Norge in Norway.
In developing the new system, CIS drew on its wealth of experience in conductor and pile installation, both on- and offshore. “Our primary objective is to employ hammer services to install conductors and drive piles with the highest standards of structural integrity, reliably and safely,” Andy Penman, group managing director, CIS, explains. “We also strive to reduce the cost of conductor and pile installation by developing more efficient work processes and using the latest technologies. The new subsea piling system makes a significant contribution to meeting these objectives.”
The system is unique in that it features self-tensioning hydraulic winches to lower and raise the hydraulic hoses and electrical cables connected to the hammer. Conventional systems rely on technicians to carry out this critical action by manually operating the winches, but the constant-tensioning ability of the new CIS system means that the winches automatically heave and lower according to the sea conditions. This automated approach has removed much of the guesswork and the risk of human error from the process, which helps
to make it more efficient, reliable and safer.
In line with the needs and expectations of offshore oil and gas industry operators, the subsea piling system features a modular and environmentally friendly design. “The focus of our approach was to develop a system that was easy to assemble and to deploy,” Penman says. “The subsea piling system has several primary components: a hydraulic hammer dressed for working subsea; a control unit equipped with instrumentation and technology to carry out and monitor the piling process; a power unit; hydraulic hose and cable winches that carry up to 300 m of hose or cable; and an upending frame.”
Conscious of increasingly stringent environmental protection legislation, CIS designed the subsea piling system to use the highest quality of biodegradable hydraulic oil.
“The process of driving piles with the new technology is very straightforward,” Penman adds. “The entire operation is carried out by an experienced piledriving engineer who monitors and controls the process from a dedicated CIS control cabin located on board a vessel or barge. A hydraulic hammer connected via an electronic umbilical cable to the control system is lowered into the water and placed directly over a subsea pile. Once it is accurately positioned, the pile is driven into the seabed by the hammer until it reaches its target depth.”
This remotely operated piling method offers a high level of control over the installation procedure, which means that the level of accuracy achieved by every hammer blow is much greater. As a result, the piledriving process takes less time, thereby delivering substantial cost savings.
“We are very proud of this technology,” says Penman. “The project we won offshore Norway provided an opportunity to showcase our piling capabilities in an important European context and, in the process, has helped to enhance our global reputation for subsea piling and conductor installation services.”
First commercial application
In early April this year, CIS also completed a contract to drive piles to secure two subsea structures permanently and to initiate three rigid pipelines that Technip Norge is installing in Norway. The contract was a breakthrough for CIS, as it was the first to utilise the new subsea piling system and the first CIS operation in Norway.
CIS drove three 30-in. initiation anchor piles, four 30-in. manifold piles and four 24-in. pipeline end manifold piles on the Bøyla development project in Norwegian waters. The field will have two subsea production wells in 120 m of water tied back to a floating production, storage and offloading vessel in Alvheim field.
The CIS package combined cutting-edge technology with highly trained engineers who could make the most of the new systems. According to Chloe Chirat, project purchaser for Technip Norge, both of these aspects were crucial in winning the project. “The combination of new techniques and expert specialists convinced us,” she says.
From a commercial perspective, the new system brings CIS’s capabilities much closer to the piling offerings from Acteon sister company MENCK. Within the Acteon business model, this overlap is seen as an opportunity to establish shared areas of expertise, work together more closely and offer a more integrated service to customers.
“In the past, CIS activities have focused on the drilling market, whereas MENCK has catered to the marine and construction sector,” says Dr Bernhard Bruggaier, executive vice president, Acteon Group. “Together, they can provide truly comprehensive piledriving capabilities to meet the needs of oil and gas operators around the world.”