The Mars oil and gas field is located in the Gulf of Mexico about 130 miles southeast of New Orleans and has been one of Shell’s most important fields over the past 15 years. Shell initially developed the field using the Mars A 24-well tension leg platform. Given the field’s sizable resources, the company assessed the need for additional infrastructure to boost production at the field. The resulting Mars B project adds new infrastructure to the Mars field and will extend its production life to at least 2050.

Challenge
The Mars B infrastructure includes an Olympus tension leg platform, with 24 well slots and a self-contained drilling rig. This production platform has 16 caissons installed in the tension legs to assist with stabilizing the platform by controlling and distributing seawater. Because offshore platforms are highly susceptible to the aggressively corrosive effects of seawater, Shell was determined to use corrosion-resistant materials whenever possible.

Shell invited RMB Products to participate in the Shell Oil Deepwater Caisson Project in 2008. Shell’s main objective was to find a corrosion-resistant replacement for the super duplex 2507 stainless steel caissons the company used previously. Shell needed fast production turnaround and required the alternative components to demonstrate equivalent or superior long-term performance.

Finally, Shell stipulated that production costs had to meet—or beat—the budgeted cost targets.

Solution
RMB Products consulted with Shell for more than two years during the design phase of engineering. The scope of the project included:

  • Design and engineering
  • Custom material formulation and compounding (high-density polyethylene—HDPE—with an added antimicrobial agent)
  • Testing and validation
  • Fabrication
  • Preparation of the host structure
  • Rotational lining with complex geometry
  • Finishing, painting, and delivery for inspection and acceptance
    RMB Products provided in-house services throughout all phases of the project and delivered products in about one-third of the time required for stainless steel components.

Results
All aspects of the project ran smoothly and all project requirements were successfully met.

Project turnaround. RMB Products delivered the product 18 weeks after Shell released the order for production, compared with the anticipated 50-week lead time for super duplex stainless steel. Both lead times included fabrication, preparation, finishing, painting, and delivery for inspection and acceptance.

Product performance. Several parts of the project required rounds of testing and validation to meet Shell’s stringent design-life specifications for maintenance-free performance.

  • RMB Products used standard and proprietary preparation processes to enhance the receiving surface of the host material and better condition it for a successful coating application.
  • RMB Products determined the manufacturing methodology to assure uniform wall thickness throughout the interior of the host structure. The complex shape varied in diameter included multiple outlets and contained an internal component that transversed the interior of the caisson with four interlocking steel rectangular ribs.
  • RMB Products and Shell collaborated to select high-density polyethylene (HDPE) for the lining material. Shell requested the addition of an antimicrobial element, requiring RMB Products to test modified batches of material until it achieved design requirements without affecting established mechanical properties.

Cost reduction. RMB Products satisfied Shell’s budget requirements. The rotational lining technology reduced manufacturing costs on the caisson portion of the Mars B project. Meeting or exceeding all other project requirements in addition to generating cost savings proved to be a winning combination for Shell. As Mars B moves ahead, the use of corrosion-resistant HDPE will increase operational life, reducing maintenance costs and long-term capital expense for Shell.

Customer satisfaction. The overall project went smoothly due to the ongoing successful collaboration of Shell and RMB Products. Shell engineers were highly satisfied with the value of the alternative manufacturing materials and technologies provided for the project. Going forward, Shell has an additional arsenal of manufacturing options—with demonstrated advantages—that it can consider for future projects.

Partnering with United Pipeline
The Mars B project also utilized numerous long, straight sections of pipe with no complex geometry. For internal corrosion protection in these sections, Shell contracted with United Pipeline to install its HDPE Tite Liner® product. Tite Liner® is pulled through long pipe sections that are straight or contain gradual bends and fit tightly against the inside of the host pipe. Rotational lining and Tite Liner® work well as complementary technologies in many HDPE projects. RMB Products and United Pipeline have partnered on such projects for more than 20 years. For more information about Tite Liner®, visit unitedpipeline.com.

About Shell
Shell, is a global group of energy and petrochemical companies and one of the largest energy companies in the world. Houston-based Shell Exploration & Production Company focuses its exploration on the deepwater plays in the Gulf of Mexico. Visit shell.com to learn more about the company and the Mars B project.

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