Synergistic Multi-Client Project
Drilling-and-completions engineers and well designers face challenging tasks in selecting OCTG materials for extreme-temperature applications (SAGD, CSS, HPHT, geothermal) in which pipe and connections are simultaneously exposed to cyclic thermo-mechanical loading and corrosive environments. These conditions lead to synergistic material damage, where various degradation mechanisms accelerate one another and lead to premature material failure. Ranking of candidate materials based on performance under synergistic loading may be different from the ranking based on response to individual loads. For example, a material may display favourable near-yield or post-yield characteristics in an in-air thermo-mechanical test, and also pass a standard NACE test with respect to sour resistance, but may perform poorly when thermo-mechanical cycles are applied in the sour environment. An adequate material evaluation method must account for the material response to synergistic loading.
Noetic has organized a multi-client project (MCP) to define an evaluation methodology for assessing of material performance under synergistic loading, combining cyclic elastic-plastic deformation, large temperature excursions, and exposure to sour environments. In addition to Noetic, four other engineering companies are engaged in this project: Alberta Innovates Technology Future (formerly Alberta Research Council), Ammonite Corrosion, C-FER Technologies, and Marion Oilfield Engineering.
The project scope consists of analytical and experimental phases. The analytical phase includes a comprehensive literature study, engineering analysis of synergistic loading, numerical modeling of downhole tubular systems subjected to extreme thermo-mechanical loads, and design of a high-complexity synergistic reference test simulating cyclic thermo-mechanical and environmental loading. The experimental phase includes various reduced-scale tests: reference NACE tests, synergistic tests on custom-designed 3D specimens machined from casing samples, and several semi-synergistic tests combining specimen pre-conditioning in air with test-to-failure in a sour environment.
Technical work commenced in December 2008, and is expected to extend to at least December 2011. Further scope expansion and next project phases are contemplated by the current participants. New participants are still welcome to join, with favourable entry terms, full access to analytical and experimental results acquired to-date, and opportunity to contribute to future project directions.
Contact: Jarek Nowinka, Email: jnowinka@noetic.ca
Phone: +1 780 414–6241 extension 122.
