Erosion pattern and structural optimization of high-pressure Y-type tee line for fracturing with high-sand content ratio

Aiming at the problem of erosion damage of high-pressure manifold components in oil and gas field fracturing operations, the effects of erosion angle, particle size, and impact velocity on erosion rate were systematically studied through a self-designed liquid–solid two-phase flow erosion test device, and an erosion model was constructed based on experimental data. The results show that the main erosion area of the Y-type tee is located at the intersection wall of the branch pipe and the main pipe, and the front section of the main pipe. The maximum erosion rate decreases first and then increases with the solid particle size (100–400 μm), and reaches the minimum value of 1.62 × 10⁻⁶ kg m⁻² s⁻¹ at 350 μm. When the particle mass flow rate increases from 1 × 10⁻³ to 5 × 10⁻³ kg s⁻¹, the maximum erosion rate increases linearly by 4.5 times. When the inlet flow rate of fracturing fluid increased from 0.3 m³ min⁻¹ to 1.5 m³ min⁻¹, the maximum erosion rate increased by 61.8 times, and the growth rate increased significantly after the flow rate exceeded 0.9 m³ min⁻¹. The structure optimization shows that the maximum erosion rate increases by 41.12 times when the spatial opening angle increases from 15° to 90° (the growth rate increases after the opening angle > 60°), and the maximum erosion rate can be reduced to 35.8% of the structure without rounded corners by setting 20 mm rounded corners. The study confirms that the particle mass flow rate and the fracturing fluid flow rate are the main influencing factors. Optimizing the space opening angle and setting the fillet can effectively improve the erosion resistance of the pipe fittings. It is recommended to strengthen the detection of the intersection wall and the front section of the main pipe to ensure the safety of the operation.