Throttling Performance and Structural Analysis of UHP Wellhead Throttle Valve

Abstract

The throttle valve， as an ultra-high pressure （UHP） wellhead device， is susceptible to erosion failure. This paper proposes the designs of spool and anti-sprint protection sleeve for double-wedge throttle valve， and analyzes the flow field characteristics of nine spools of the double-wedge throttle valve at different openings. The results show that the spools of the double-wedge throttle valve are better-performed in erosion resistance than that of the single-wedge throttle valve. With the increase of spool stroke， the velocity of drilling fluid passing through the wedge-shaped surface of the spool increases， and the drilling fluid has a strong erosion to the spool and the wall surface below the spool. Among the 9 types of spools of the double-wedge throttle valve， the convex symmetrical spool has the best throttling and anti-erosion performance， and its linear regression coefficient of pressure drop curve is 99.6%. The cavity size has a significant impact on the performance of the throttle valve： expansion of the cavity size by 30 mm leads to a decrease of maximum velocity by 3.87% on average. After the spool anti-sprint protection sleeve is installed， the maximum fluid velocity decreases by an average of 30.35%， extending the service life of the spool. The research results provide a reference for the design and application of UHP wellhead throttle valves.

Keywords

• uhp wellhead
• wedge throttle valve
• double⁃wedge surface
• erosion and wear
• design optimization