Simulation Study on Ultra-High Pressure Rupture Disc of Pressure-Controlled Testing Tool

Abstract

In APR formation testing technology, the ultra-high pressure rupture disc is a core component ensuring the reliability of downhole operations. Aiming at the requirements for performance optimization and precise design of rupture discs under ultra-high pressure downhole conditions, this study adopts Inconel 718 nickel-based alloy as the bursting disc material and establishes a three-dimensional simulation model with reference to the 17.5 ksi rupture disc of OSECO Corporation. The effects of initial thickness S0, arch height H, top thinning thickness t0 and temperature on the stress distribution and rupture characteristics of the bursting disc are systematically analyzed using simulation software. The results show that increasing the initial thickness and arch height can reduce the degree of stress concentration and improve the burst pressure; the top thinning structure can transfer the stress concentration zone from the arch base to the arch crown to achieve controllable rupture, which is consistent with the actual failure morphology; the influence of temperature on burst pressure is mainly reflected by the attenuation of yield strength, and the fitted temperature-burst pressure curve agrees well with the trend of similar products of OSECO. This study verifies the adaptability of Inconel 718 alloy and the rationality of structural design, providing a theoretical basis and technical support for the design optimization and engineering application of ultra-high pressure rupture discs.