Communications Technology That Can Weather Any Storm

By Zhong, Qian

The Impact of Optical Add/Drop Multiplexing Technology on the Offshore Community The 2005 hurricane season unleashed five unforgiving storms on the southern United States and gulf coast. Hurricanes Katrina and Rita battered the United States, resulting in unprecedented levels of destruction to offshore oil and gas rig infrastructures. According to the National Ocean Industries Association, the impact of the 2005 storms on the Outer Continental Shelf was severe; destroying 113 offshore platforms, seriously damaging 52 more and shutting in over 95 percent of offshore gulf crude oil production, or roughly 27 percent of total U.S. crude oil production.

Unpredictable weather will continue to rear its head, as predicted by the National Oceanic and Atmospheric Administration, as weather patterns constantly change. This poses a challenge the offshore community must face: how can oil and gas providers proactively minimize downtime and speed up the recovery efforts of future damage? The need for communications is becoming a paramount concern in such disastrous events. In efforts to prepare for the unknown, rig operators are looking to identify a reliable communications technology that can protect rigs from the dooming cost of uncertainty.

Reliable Communications Costs

To understand the significance of communications to a platform/ well operator, it is important to note that unplanned events cost the oil and gas industry more than $1 billion every year, according to Schlumberger Ltd. (Houston, Texas). The revenue from a single platform can easily exceed $10 million per day. For example, a single floating platform in a water depth of 1,900 meters with 25 subsea wells is designed to produce 250,000 barrels of crude and 200 million cubic feet of natural gas per day. At current wholesale market prices, this output has a value of over $15 million per day.

The need for reliable communications is further emphasized when examining the impact each threatening storm imposes on an offshore platform. For example, when turbulent weather is predicted, platform evacuation is announced days in advance of the storm’s arrival. With the assistance of communications-driven equipment and monitoring systems, the platforms can remain in remote operation throughout, minimizing downtime and facilitating faster recommissioning after the storm passes. The implementation of a reliable communications system supports the return to production in a much shorter period and averts a catastrophic loss of the platform’s functionality without compromising the safety of workers.

Identifying Reliable Networks

For the last 20 years, undersea fiber optic networks have been deployed in the world’s oceans and seas to provide secure and reliable telecommunications connections between countries as well as for domestic applications. Standard subsea systems are designed to transmit extremely large amounts of capacity between relatively few shore facilities. The technical capabilities of these systems, offering a cable capacity in excess of five terabits per second via wavelength division multiplexing of 10 gigabits per second data streams over multiple fiber pairs, can more than meet the bandwidth and security needs of the oil and gas industry. Hence, the cost of communication as measured by dollars per gigabit is not effective in utilizing the traditional dedicated subsea cable systems.

Optical add/drop multiplexing (OADM) is an emerging technology that enables sharing of the bandwidth with multiple platforms, but reserves the reliability of the subsea systems. An OADM technology differs from standard subsea systems by using the available bandwidth to distribute smaller units of capacity to a large number of offshore platforms by offloading from a main trunk. OADM technology connects a chain of rigs to the backbone of one undersea fiber optic network.

Each platform is provided with a dedicated channel and bandwidth, which allows traffic to continue flowing in the event that another rig’s connection is interrupted. Fully integrated OADM, a state-of- the-art communication infrastructure element, further strengthens a communications network with dedicated, protected bandwidth, enabling constant communications with offshore rigs during turbulent events. This technology is particularly suited to point-to-mullipoint transmission architectures, typically found in Internet protocol data networks.

OADM

OADM is an add/drop multiplexer system specifically designed to insert and remove optical (10 gigabits) wavelength channels from a linear or ring network. Lower level tributaries, such as E1 or gigabit Ethernet, interface the 10 gigabit per second rail via standard networking equipment, such as routers and multiservice synchronous optical network/synchronous digital hierarchy platforms.

The enabler for deploying such OADM technology is a powerswitched branching unit (OADM-PSBU), designed for use in systems requiring multiple undersea branching with optical connections. The OADM-PSHU provides optical channel connectivity from each branch leg onto the repeatered system’s main cable, also referred to as the trunk, via its passive OADM optical circuit. The OADM-PSBU also provides the ability to remotely switch the electrical power path of the undersea cable for fault isolation during repairs.

The OADM-PSBU is a broadband system that splits the full optical spectrum of a trunk fiber between the branch cable and the straight- through trunk fiber path. This flexible approach allows a single OADM-PSBU design to be used at any location in the system and serves as a universal spare. The advantage of incorporating universal configured branching units into a system presents an attractive solution from the operational expenditure perspective.

The OADM-PSBU power switching feature is controlled remotely and enables system reconfiguration during hurricanes and other external events, maintaining traffic in nonaffected segments during marine maintenance operations. The system’s internal electrical connectivity is controlled by an optical signal delivered to the branching unit through the same optical fibers used to carry traffic. The electrical switching features support a system design in which the trunk can connect to the sea ground at any branching point without affecting traffic through the system.

In the event of a system cable fault, such as damage to one connected rig, this feature enables any segment of the trunk to be grounded at both ends during repair operations, while reliably maintaining traffic to all platforms connected to the system. The branching unit can be configured to support fault location techniques, such us electroding, of the branch and trunk cables from an electroding resource at a branch terminal. The remote switching capability is initiated from any shore station and requires no connection to or action from any of the branch platforms. This feature makes network security independent of the presence or operational capability of any platform or series of platforms, a feature that is highly desirable in the event of a disaster.

The optical transmission configuration of a typical implementation of Tyco Telecommunications’ OADM-PSBU is reduced to four platforms for simplicity, served by a single fiber pair. Each platform communicates directly with each cable station on a unique, dedicated channel independent from any other platform. A fiber pair configured for eight wavelength division multiplexing channels ean serve four platforms, each with two paths to shore. The concept is easily extendable to tens of platforms per fiber pair.

In the event of a fault in the trunk cable. OADM-PSBUs can be reconfigured from the cable stations to electrically isolate the faulted segment during a marine repair. During the trunk repair, all platforms can maintain communications with one cable station.

Offshore Oilfield Nettworking

BP America Inc. (Warrenville, Illinois) recently chose Tyco Telecommunications to construct an undersea fiber optic system with OADM branching units to serve offshore platforms in the Gulf of Mexico. The 800-mile undersea fiber optic system will provide continuous broadband connectivity to the company’s offshore oil and gas facilities.

The system will allow greater operating flexibility, including the ability to continue safe production for extended periods when turbulent weather threatens the gulf, and return more quickly to production after storms pass. The implementation of the OADM network will enable the onshore BP staff to control offshore facilities remotely without having to close them down during personnel safety evacuations, bach year, hurricane-related shutdowns reduce oil and gas deliveries to refineries and power plants, sometimes resulting in higher gasoline and electricity prices or shortages.

The reliable long-haul undersea fiber optic technology will supply each BP platform with direct optical connectivity to landing stations, ensuring continued operations, independent of any other platform in the system during hurricane evenis. This project is part of BP’s overall strategy to ensure that key oil and gas production facilities around the world provide reliable supplies to market at times of greatest need. The Gulf of Mexico network will incorporate an upgrade capability designed to support 64 platforms with excess commercial bandwidth available for third-party deepwater operators. Conclusions

When considering the importance of their communication systems and determining which communications system to choose, oil and gas companies must consider that proven and innovative high-performance communications solutions, like undersea cables utilizing OADM, can increase revenue, profitability and oilfield yield, lessen environmental impact and improve worker safety.

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The typical optical transmission configuration of a telecommunications optical add/drop multiplexing powerswitched branching unit, reduced to four platforms served by a single fiber pair.

The configuration power of a four-platform network during a trunk cable fault. During repairs, all platforms can maintain communications with one station.

“In efforts to prepare for the unknown, rig operators are looking to identify a reliable communications technology that can protect rigs from the dooming cost of uncertainty.”

By Dr. Qian Zhong

Director of System Designs

Tyco Telecommunications

Eatontown, New Jersey

Dr. Qian Zhong, director of system designs for Tyco Telecommunications, has more than 15 years of experience in the telecommunications industry. At Tyco Talecommunications, Zhong is responsible for the design and provisioning of state-of-the-art global telecommunications systems. Zhong holds a Ph.D. in engineering and an M.B.A.

Copyright Compass Publications, Inc. May 2007

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