Simulation’s Role in the Oil & Gas Industry
In a previous article I wrote about the role that simulation can play in the design and optimization of mining equipment. This time I would like to continue the broader topic of simulation’s role in the natural resources sector by giving special attention to the Oil & Gas industry and the applicability of CAE software in this demanding industry.
Oil and Gas drilling takes into account a variety of equipment: crown and crown block situated at the apex of the rig, traveling block, draw works, sand pipe, engine, fuel or water tanks, swivel, rotary hose, turn table, pipe rack, conductor pipe, bore hole, bit, drill pipe, mud pit and mud pump.
But drilling process in oil & gas extraction is well-known. Most interesting is that the same drilling infrastructure can perform seismic surveys based on shock waves generated by:
• Compressed air guns that shoot pulses or columns of air into the water for sea-platforms
• The thumper trucks used for drilling by slamming heavy palates into the ground for exploration over the land
• Explosives that are inserted into the ground by drilling for exploration over the land or taking it over board for exploration over water and detonated
Generated by the drilling infrastructure, the shock waves travel to the heart of the earth and are reflected back to the surface by the different layers of rocks. The reflections travel at varying speed depending on the density or category of layers of rock through which they pass. The shock waves are reflected and picked up by the audio sensitive vibration detectors or microphones: in the land, the drilling parts consist of seismometers, while those on the water are done by the drilling hydrophones. In this way the seismologists can interpret the anomalies associated with typical structures for gas or petroleum traps and oil.
Simulation for Oil & Gas Industry
The typical simulation analyses used to improve the performance of oil & gas equipment are:
• Drilling columns – structural stress & dynamic, CFD, thermodynamic
• Hydropower devices – structural and multiple CFD
• Pumps – structural, CFD, thermodynamic
• Pipes system (industrial water, petroleum) – structural stress and fluid dynamics
• Storage tanks (fuel tank, oil tank, pressure vessel, etc.) – structural pressure, fluid circulation
• Oil platforms – structural static & dynamic
But more practical is to see relevant simulations in real examples. Here are some interesting projects for Oil & Gas equipment and accessories described in the SimScale Public Projects:
1. Wave Impact on an Oil Rig Platform
This project simulates the impact of sea waves against the columns of an oil rig. A scaled geometry that maintains the Froude number of the actual phenomenon is used. The geometry was meshed on the platform using the snappyHexMesh tool. The resulting mesh consists of approximately 8 500 000 volumes.
2. Thermostructural Analysis of a Pressure Vessel
A very interesting simulation with applications in extraction and preservation of underground excavation is this thermostructural analysis of a pressure vessel. Pressure vessels are normally used for storing high pressure liquid or gas. In this simulation, a copper pressure vessel was considered with a steel coating inside containing the hot water having temperature of 593 K (290 °C) which was cooled down by a cold water at 293 K (25 °C).
For the analysis, transient thermostructural was selected since temperature is changed over time. Copper was selected as the vessel material whereas steel was selected for the inner coating.
The material table which contains the material parameters at different temperatures was uploaded. The vessel has two pipes; upper pipe for cold water inlet and lower pipe for hot water outlet. Imaginary valves were considered between pipes and the vessel. The simulation results show the temperature, heat flux and stresses in pipes and vessel at 2020 seconds (33.75 minutes).
3. Sloshing of Fluid in a Moving Fuel Tank
Also, an important project for petroleum storage is this simulation of sloshing of fluid in a moving fuel tank. Movement of the fuel tank was assigned by the Solid Body Motion option for the tank. The geometry is a 30 gallon cylindrical tank. The inside domain was meshed using the SnappyHexMesh on the SimScale platform and has about 0.5 million cells.
For this sample project, the fluid is assigned properties of water and the second phase is air. The simulation was run on 8 compute cores and took around 11 hours to complete.
All the projects presented in this article can be imported into your own workspace and used as templates. Feel free to browse the SimScale Public Projects for other interesting simulations.
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