- Award winning new field joint coating technology
- Cost reduction for ultra deepwater pipelines
- Viable filed joint coating solution with proven technology
This year at Offshore Pipeline Technology (OPT) Conference 2017, Shawcor was presented the Technology Innovation Award for NEMO Hybrid field joint coating, a two-layered injection molded field joint for pipeline applications WO 2016115634 A1 (Patent Pending).
Suresh Choudhary, Technical Lead Americas, Flow Assurance Technologies at Shawcor presented NEMO Hybrid field joint coating, to address material cracking during the reeling process.
Technology Innovation Award, OPT 2017.
The following sections outline the features and benefits of the new technology innovation being awarded at OPT 2017:
Need for this New Technology
As oil and gas companies push the boundaries of existing technologies, pipelines must also evolve in order to address these new operating parameters. Along the length of all pipelines, one of the most critical and vulnerable areas is the welded joint between the fused pipes. Ultra deepwater pipelines, requiring an extremely thick layer of thermal insulation coating, need to mitigate against material cracking at the field joint during the reeling process. Excessive cracks during reeling process will result in expensive repairs offshore due to additional vessel time. In addition to the cost, operators are also concerned about the integrity of repairs for the design life.
NEMO Hybrid Field Joint Coating
To address material cracking during the reeling process, Shawcor has introduced its NEMO Hybrid field joint coating. The Hybrid field joint consists of an hour glass shaped layer of Injection-Molded Polypropylene (IMPP) insulation coating to approximately 30mm thickness, which acts as a heat barrier. This is followed by NEMO 1.1 infill to complete the body of the field joint and achieve the ductility needed during reeling, without creating added stress in the parent coating. NEMO 1.1 infill is an epoxy-urethane hybrid system, processed similar to existing polyurethane materials.
Shawcor NEMO Hybrid Technology.
This solution underwent rigorous installation (using reel vessel) and subsea operation testing. This is a technically, operationally and commercially viable solution which fits in with existing footprint on the spoolbase without increasing cycle time of the process. It has been successfully deployed this year in the Gulf of Mexico for a major operator.
Innovative Field Joint Coating
The NEMO Hybrid field joint solution allows operators to expand the capability envelope of wet insulation technologies to deeper water. Without this solution, the operator will have to pay for additional 10-20% vessel time to fix the field joint cracks offshore. Alternative technology such as pipe-in -pipe may be used but the requirement of two thick walled pipes for deepwater also requires higher load capability vessels. The NEMO Hybrid field joint solution uses a new epoxy-urethane material that has improved ductility but is processed using an existing process footprint obviating the need for additional CAPEX.
Injection Molded Polypropylene (IMPP) field joints have been used in the industry for decades as a compatible field joint for five layered syntactic and foamed polypropylene line pipe. In last couple of years, industry has seen a higher percentage (three commercial projects since 2014) of cracking of IMPP field joints during reeling process. Pipe-in -pipe system could be a technically viable alternative but commercially less attractive for deep water rendering projects economically infeasible. NEMO Hybrid development started in 2014 as potential solution for a commercial project facing severe cracking issues and was successfully deployed in 2016 with issues resolved.
- Over 15 reeling simulation trials in winter conditions in Norway for different reeling radius ranging from 7.5m to 9.75 m
- 4 subsea simulated service vessel testing validating the thermal performance of the system
- 2 tensioner trials determining installation capability
- Long term material ageing tests
Broad Interest in the Technology
The concept of dual layer field joint system is not only limited to polypropylene line pipe systems but can be extended to polystyrene and other extreme temperature polymeric materials. The solution is not just a material innovation but also it is also a different way of incorporating materials within the field joint system that combines high temperature resistant material with a low temperature ductile material. This technology will allow broader use of wet insulation technology for deeper water and improving economic feasibility of deep water projects.
Significant Impact of the Technology
The exotherm during the reaction of this epoxy-urethane material is very low thereby reducing the temperature on the surface of freshly casted field joint. This could be important benefit from HSE perspective as the joints can be safely handled within few minutes of casting thereby eliminating the hazards of hot body in the work area (onshore or offshore) for a longtime.