Dynaflow Research Group (DRG) conducted comprehensive pipe stress analyses for a large oil and gas extraction facility. This facility comprises three onshore flow stations, one offshore flow station, and a gas export compressor station. Crude oil and gas are transported from the wells to the flow stations, where the crude oil and gas are separated. The oil is then pumped to storage tanks for shipment, while the natural gas is directed to the compressor station. At the compressor station, the gas is compressed to 150 bar through multiple stages and subsequently transported via a pipeline.
Pipe Stress Analysis
Scope and Methodology
DRG’s analysis encompassed both static and dynamic pipe stress evaluations, focusing on critical lines identified as multiphase flow lines, large diameter pipes, piping connected to reciprocating equipment, and fiberglass piping. Emphasis was placed on assessing flange loads and the loads on equipment connections.
The stress analysis covered various load scenarios, including operational loads, design loads, and wind loads, with results compared against relevant engineering codes. For sections of the facility with existing piping, a fitness-for-service assessment was performed. Additionally, a pulsation study was conducted for piping connected to reciprocating equipment to evaluate dynamic stresses across different compressor operating frequencies.
In total, DRG analyzed several hundred isometries and examined nearly one hundred nozzle connections.
Results and Recommendations
The analysis revealed that, at several locations, piping, flanges, and equipment nozzles were subject to overloading under certain load conditions. Most overstress issues were mitigated by relocating pipe supports or modifying their functionality. For specific cases, DRG recommended rerouting pipelines to reduce loads on flanges and nozzles. In instances involving pressure relief valves, DRG advised using higher-rated flanges to manage the substantial relief loads when the valves are activated.
Throughout the engineering phase of the project, DRG maintained close communication with the client. Additionally, DRG provided training courses to the plant’s lead engineers, focusing on static and dynamic stress analysis techniques and addressing key construction issues pertinent to such facilities.
The stress analysis covered various load scenarios, including operational loads, design loads, and wind loads, with results compared against relevant engineering codes. For sections of the facility with existing piping, a fitness-for-service assessment was performed. Additionally, a pulsation study was conducted for piping connected to reciprocating equipment to evaluate dynamic stresses across different compressor operating frequencies.
In total, DRG analyzed several hundred isometries and examined nearly one hundred nozzle connections.
Conclusion
DRG’s pipe stress analysis ensured the structural integrity and operational efficiency of the oil and gas extraction facility. By identifying potential stress points and providing practical recommendations, DRG contributed to the facility’s safe and effective operation.
