Subsea Gate Valve-PDC Material and Sand Slurry Test

Area of Science:

• Materials Science
• Mechanical Engineering
• Petroleum Engineering

Background:

• Subsea gate valves are critical for well control, but failures due to erosion and wear in harsh environments are common.
• Current tungsten carbide (WC) coatings face limitations in extreme conditions, leading to frequent maintenance and high costs.
• Reliability of subsea valves is paramount due to the significant HSE risks and expenses associated with maintenance and replacement.

Purpose of the Study:

• To evaluate the performance of polycrystalline diamond compact (PDC) coatings as an alternative to tungsten carbide (WC) for subsea gate valves.
• To investigate the erosion resistance of PDC coatings under simulated subsea slurry conditions.
• To quantify the potential improvements in valve lifespan and reliability offered by PDC coatings.

Main Methods:

• Experimental testing to compare friction and wear properties of WC and PDC coatings.
• Development of a 3D subsea gate valve model for computational fluid dynamics (CFD) simulation.
• Simulation using Ansys Fluent 2024 R2 with Oka erosion and Discrete Phase Models under API slurry test conditions (2% sand slurry, 250-400 μm).

Main Results:

• PDC coatings demonstrated reduced friction and wear compared to WC.
• Simulations showed PDC coatings reduce erosion depth by 77.6% in a 5-inch gate valve.
• The use of PDC coatings is projected to extend the valve lifetime by 4.5 times.

Conclusions:

• PDC coatings offer superior erosion resistance compared to traditional WC coatings for subsea gate valves.
• Implementing PDC coatings can significantly enhance the durability and operational life of subsea valves.
• The findings support the adoption of PDC materials for improved performance and reliability in demanding subsea applications.