As even a casual newswatcher knows, offshore drilling can be a dangerous enterprise. Among the safety hazards is the ocean itself with its unpredictable and sometimes intense currents exerting forces on the floating platform.
Researchers at Los Alamos National Laboratory used advanced simulation software to help improve the safety of ultra-deep floating oil rigs by studying how the surrounding currents affect the motion of the platform. As highlighted in a recent article, the project responsible for carrying out these computational fluid dynamics (CFD) numerical simulations was recognized as an ANSYS Hall of Fame finalist.
As land-based oil resources reach a saturation point, industry pushes into ever more challenging environments to satisfy current and future fuel demands. Most of the earth is covered by water, said Dusan Spernjak, a member of the laboratory’s mechanical and thermal engineering team, so it follows that most of the earth’s fossil fuel stores are likewise submerged. “Designing a floating structure for offshore deep water oil drilling is a challenging task because drilling starts deep under the sea surface with no infrastructure in place,” Spernjak added.
The research team, comprised of mechanical and thermal engineering experts, used ANSYS Fluent simulations to analyze the motion of the floating structure resulting from complex fluid–structure interactions and vortex shedding. The phenomenon called vortex-induced motion (VIM) is highly complex with limited experimental data, so researchers must rely on advanced numerical simulations and supercomputers for answers.
In real-world terms, vortex-induced motion from the ocean currents jeopardizes the integrity of key components related to system safety, such as the riser and mooring systems of the drilling station. The research shed light on methods of mitigating this impact.
“The simulations reveal insights into the physics of vortex shedding and VIM at different length and time scales,” according to the piece, “The immediate benefits include the improved process for design optimization for large floating structures, and possible strategies for vortex-induced motion improvement.”
The successful project led to the team finishing as a finalist in the 2015 ANSYS Hall of Fame Simulation Competition.
“Recognition from ANSYS for our effort to improve offshore drilling safety brings global exposure to the diverse science and advanced engineering conducted by the Laboratory and our team,” Spernjak reported. “Making their Hall of Fame is the result of a great team effort, from our postdoc Seung Jun Kim to our industry partners, with support from Los Alamos high-performance computing.”
The Research Partnership to Secure Energy for America (RPSEA) funded this effort and the LANL Institutional Computing Program provided computational resources.