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During the drilling, the flow field characteristics of the vertical well inclinometer are complex. In a harsh underground environment, the valve head is prone to erode and wear. To overcome these disadvantages, the three-dimensional (3D) model of the valve head of a vertical well inclinometer was developed, and the flow field and erosion characteristics were simulated by using a numerical program. Results show that the maximum velocity and the maximum turbulence effect occur at the throttling inlet through which the drilling fluid passes the guide sleeve. By analyzing the particle trajectory of the discrete phase model, it is found that the particles above the valve head surface have obvious accumulation and rebound phenomena and that the erosion effect appears to some extent on the valve head surface. Analysis of the shear stress on the surface of the valve head shows that the stress concentration occurs in the valve head directly impacted by the drilling fluid and in the groove of the flow drilling fluid, respectively. The feasibility and accuracy of the simulation are verified by comparing the theoretical results with that of the field test. This investigation can be used to explain the failure of the valve head of the vertical well inclinometer and provide the design and optimization of the valve head with scientific support.
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