Pipelines in deep water – improved monitoring of corrosion and flow

Citation

(2001), "Pipelines in deep water – improved monitoring of corrosion and flow", Anti-Corrosion Methods and Materials, Vol. 48 No. 5. https://doi.org/10.1108/acmm.2001.12848eaf.001

Pipelines in deep water – improved monitoring of corrosion and flow

Pipelines in deep water – improved monitoring of corrosion and flow

Keywords: InterCorr International, Shell Global Solutions, Pipelines, Corrosion monitoring

Exploration and production in the deep waters offshore can be compared to exploring in deep space. In both areas, it is extremely difficult to maintain equipment because of inaccessibility. And, in the famous words of Gene Kranz, flight director at NASA during Apollo 13: "Failure is not an option."

Dr Andrea Etheridge, senior consultant for InterCorr International, Inc., the corrosion solutions company, says:

You can't easily send a person down 3,000 to 9,000 feet to check on deep water pipelines. You can't easily intervene if problems develop, either. The systems that monitor oil and gas production and the corrosion of pipelines must be fail-safe and in place when the flow lines are installed on the ocean floor.

Corrosion-related failures, or excessive corrosion rates at today's tremendous oil production depths can be extremely expensive if left unchecked as well as being potentially dangerous to the environment, Etheridge explains.

A new joint industry program, launched in April by InterCorr International, Inc. and Shell Global Solutions (US) (a division of Shell Oil Products company), will investigate cost-effective and reliable systems for monitoring corrosion and flow assurance in subsea pipelines.

In addition to Shell, other oil companies taking a lead role in developing the program are BP, Intevep-PVDSA, the R&D arm of Venezuela's national oil company, and Perturbs, the national oil company of Brazil. Input gained through two focus group meetings with these and other companies has helped to develop the scope of work for this major joint industry development effort.

"We expect to have about ten to 15 participants in the program, including oil and gas producers, major suppliers and service companies," says Etheridge.

"Shell Global Solutions" is a trading style used by a network of technology companies of the Royal Dutch/Shell Group.

"Those who sign early – within 90 days after the program starts – will save about 25 percent of the cost to participate," she says. "Our experience has shown that most companies recoup their participation costs in this type of program with only a single application of the technology."

Offshore oil comes from the ground in flow lines at high temperature, but then is rapidly cooled by deep water at low temperatures once it is in the subsea pipeline. This can cause precipitation of water that increases corrosivity and can also cause deposition of waxy substances, both of which can jeopardize flow, system integrity and ongoing operations. Until recently, producers saw the rate of flow and corrosion of pipelines as independent problems. The new InterCorr/Shell Global study will address both of these concerns and provide a common solution, says Etheridge.

One of the problems currently experienced by deep water operators is that only limited monitoring options are available today and none has been proven in deep water service. The major purpose of the InterCorr program will be to integrate several monitoring capabilities into a single unit and verify their performance under simulated deep water conditions in advance of a field trial.

The new program will develop an enhanced, multifunctional monitoring capability that integrates existing, high reliability technologies capable of monitoring corrosion and flow assurance. This system will be adaptable to subsea, pipe-in-pipe, insulated or buried flowlines. The program will also provide a demonstration of long-term system performance and reliability under simulated deep water conditions.

Effective corrosion monitoring and flow assurance of subsea flowline installations remains a challenge. In deep water projects, flow lines are the most capital-intensive parts of the project. In the Gulf of Mexico and many other field developments around the world, these lines are made from carbon and low alloy steels to minimize cost. However, to achieve this cost benefit, the carbon and low alloy steels must be adequately protected against corrosion by chemical inhibitors and must be monitored for sand erosion, scaling and organic solids deposition which jeopardize production.

Excessive deterioration or loss of flow can lead to lost production, failure, or the need for repair. The consequences in deep water can range from very expensive to cost prohibitive. Therefore, it is critical to develop pipeline monitoring capabilities for deep water systems.

Etheridge explains that the new monitoring and corrosion control system will be designed around the following anticipated requirements: continuous corrosion rate measurements and wall thickness data at multiple points of interest rapid response monitoring capabilities for both general and localized corrosion multi-functional capabilities that also include monitoring of flow, sand erosion and scale/organic solids deposition:

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  Effective, reliable operations in deep water subsea environments.

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  Interface with existing hardware systems for field production monitoring.

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  Reliable transmission of data at regular intervals using modem telemetry technology.

Sponsors of the program will receive a preferred position over non-sponsors in terms of technology availability and cost. Consultants to the program will be Dr Russell D. Kane, senior consultant, and Peter Pratt, sales manager, both with InterCorr. Combined, they bring more than 50 years of oilfield corrosion and monitoring experience to the program.

Details available from: InterCorr International: UK, Europe and Asia Pacific: Dr Andrea Etheridge. Tel: 0 11-44-207-53 8-4982; E-mail: aetheridge@intercorr.com North and South America: Dr Russell D. Kane. Tel: +1 281-444-2282; E-mail: rkane@intercorr.com