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Front Cover Story April 2015 - Global Marine proves its oil and gas credentials

Published:  21 May, 2015

Against a backdrop of proven capability, innovation and quality in subsea cable installation, Global Marine Systems Limited is making impressive inroads into the oil and gas market. With a rich history in underwater engineering dating back to the 1850s, the company has evolved to become a renowned name in the design, installation and maintenance of high speed fibre optic communications networks.

Instead of specialising in cables that travel from country to country, the focus for the oil and gas industry is shore to platform, as well as platform to platform installation and connectivity services, along with permanent reservoir monitoring (PRM) solutions in both deep and shallow water.

Among the secrets of a successful subsea cable engineering project is the provision of a whole life solution, from concept with cable route planning, to project engineering, installation, and comprehensive maintenance solutions. Such capability generates a position of strength when it comes to providing the oil and gas sector with a variety of innovative underwater cabling services.

Rising demand

Broadband data networks are rapidly emerging as the most effective technology to support diverse advances in oil and gas field management. These help manage risk, supervise remote drilling operations and use real-time information to drive field economies. Field information is critical intelligence because rapid sub-surface and production data analysis can lead to enhanced recovery. Furthermore, real-time communications provide benefits such as improved health, safety, staff welfare and quality of services in offshore facilities.

So, what does a typical subsea engineering project comprise? Well, the first stage following concept is typically pre-project planning. Here, it’s necessary to provide an end-to-end solution including desktop survey, route survey and route engineering.

Aspects such as the marine surveys typically use geophysical survey tools like echo sounders, sonar, sub-bottom profilers and magnetometers. When combined with geotechnical sampling, these help provide a comprehensive set of data which is charted and incorporated into cable routing GIS software.

All-encompassing route position lists and straight line diagrams detail the position and complete aspects of the cable route such as the cable plant (branching units, repeaters, joints, beach manholes), cable lengths, armour types, transitions, slack, water depths, cable and pipeline crossing points, and maritime boundaries.

Connecting the future

In terms of fibre connectivity, for both platform to shore and platform to platform projects, the aim should always be to deliver the customer’s data network requirements in a way that ensures reliability. The importance of reliable in-field communications is paramount, for both faster data analysis and contact between destinations.

To ensure every project is a success, staff must possess comprehensive skills and experience of working with small diameter cables is seen as an advantage. In addition, an appreciation of subsea equipment is paramount, as is recognising the appropriate solution for the application. For instance, in respect to trenching and burial capability, subsea equipment should provide the the capability to operate at water depths up to 2500m with burial capability to 2m below the seabed. In fact, for customers requiring even deeper burial, or burial in denser sea beds, rock cutting technology should be sourced.

Another important aspect to successful submarine cable installation is vessel support. Here, specialist cable ships should feature DP2 dynamic positioning, along with a crew that has extensive worldwide experience in the installation of small diameter cable, and a proven track record of operating within close proximity of oil and gas platforms.

The key to subsea success

While these specialist vessels handle surface operations such as cable planning, deployment and management of the cable as it descends through the water column, underwater efforts are performed by remotely operated vehicles (ROVs). The availability and suitability of these machines is imperative as they are able to traverse complex underwater environments in order to trench, bury, manipulate and inspect subsea cables. Any customer looking to appoint a subsea cable engineering partner should ensure that prospective suppliers such as Global Marine house a fleet of ROVs capable of performing a multitude of underwater tasks in varying degrees of ocean depth and in different sediment types.

Of course, proven J-tube and I-tube design and fabrication capabilities pave the way for successful installation to the platform itself. In combination with riser analysis, cable pull‐in design and engineering, cable pull‐ins, hang-offs, offshore hook‐up and commissioning, suppliers such as Global Marine ensure the offer for customers is suitably comprehensive. Needless to say, expert cable deployment and protection solutions such as mattressing and burial are vital for J-tube and I-tube projects, as they are for PRM.

PRM is a relatively new method of subsea terrain monitoring designed to enhance the efficiency of oil recovery. The process enables a company to decrease field risk by providing a better image of subsea reservoirs during extraction operations. Because the monitoring equipment remains onsite, oil companies are able to better manage oil reservoirs throughout their life cycle.

Designed to improve operational costs and drilling efficiency, PRM uses permanently installed sensors to detect the properties of sub-surface oil reservoirs. Demand is also expected to heighten as oil companies place ever greater emphasis on securing maximum extraction from a single field, as opposed to sourcing a new site, which is a far more expensive alternative. In all cases, extensive experience with the types of smaller diameter cable, as well as sensor deployment used in PRM installations, will enable more efficient deployment.

Joint benefits

With regard to fibre-based cable jointing technology, founding members of the Universal Joint Consortium (UJC) such as Global Marine, are best placed to provide customers with all the piece parts, tools, equipment and training required to install and maintain the Universal Joint (UJ) and Universal Quick Joint (UQJ).

On the subject of maintenance, it is clearly imperative that system downtime is minimised and that a broken segment of cable is repaired in a timely manner. Here, the best suppliers should be able to provide a variety of maintenance options that reflect individual requirements for quality, reliability, responsiveness, dependability, and speed of repair. Maintenance solutions are delivered typically via consortiums or, in some cases, through private agreements.

As a point of note, all of the skills developed by Global Marine for the benefit of its oil and gas customers are in principle fully transferable to other sectors that may be able to leverage this expertise.

Success stories

Among many oil and gas industry success stories for Global Marine is a project delivering platform to platform fibre connectivity in the North Sea for offshore communication network specialist, Tampnet and its customer, a major international oil company. Most recently this entailed the installation of 87 km of fibre optic cable between three platforms that incorporated the deployment of three branching units.

The solution required Global Marine to provide an end-to-end range of services encompassing all elements leading to installation, including: marine survey and route engineering; marine permits; route clearance; pre-lay grapnel runs; mattress installation over pipeline crossings; cable installation including plough burial; post lay inspection and burial; and the provision of detailed post installation information.

The company’s Cable Innovator vessel successfully executed the installation phase of the project operating in close proximity to both pipelines and platforms.

“We have been very pleased with the delivery of the project and the working partnership that has grown between Global Marine and Tampnet,” says Anders Tysdal, Technical Director of Tampnet. “The major oil companies are some of the most discerning customers in the world and working with businesses that enable us to meet those standards is of great importance.”

Global Marine is currently continuing with the fourth phase of work in the North Sea for Tampnet.

Fibre connectivity

Another notable North Sea project saw Global Marine facilitate 110 km of fibre connectivity to link the Valhall and Clyde platforms for client, NSC. The project involved cable plough installation to 1m below the seabed and a scope of work which included six pipeline crossings and a J-tube cable pulled through to the Clyde platform, as well as a branching unit.

The ship used to complete the work was C.S. Sovereign, the vessel worked in tandem with Atlas, an ultra-heavy work class ROV designed for intervention, trenching, umbilical and power cable maintenance, post lay and inspection roles. Also deployed was Hi-Plough, which has been designed to operate to depths of 1500m and is capable of installing cable, repeaters and cable splice boxes. The plough is equipped with a cable tracking system and forward obstacle avoidance sonar.

Over the years, Global Marine has proved itself as an ideal partner to manage risk and maximise the return of investment on underwater cable projects for the oil and gas market.

Global Marine Systems Limited

New Saxon House

Winsford Way

Boreham Interchange

Chelmsford

Essex UK CM2 5PD

www.globalmarinesystems.com

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