Modified Approach for Predicting the Remaining Strength of High-Strength Gouged Pipelines

Abstract

With the increasing application of high-strength carbon steel pipes in oil and gas transport pipelines, a precise evaluation of such pipelines is of the utmost importance for the optimum and safe utilization of oil and gas resources. Gouge defects caused by external factors are among the major factors in reducing the strength of pipelines. Therefore, an accurate evaluation of gouged pipes is highly important for pipeline integrity management. This study used a semiempirical method to predict burst pressure in high-strength gouged pipelines. To this end, the nonlinear finite-element method was used to evaluate the effect of various factors, including material properties, strain hardening exponents, and pipe and gouge defect geometry on the remaining strength of high-strength carbon steel pipelines. Finally, a formula was provided to predict the remaining strength and burst pressure of the gouged pipelines. In order to validate the formula, full-scale burst pressure tests were used. The results of the predicted burst pressure using the developed formula were shown to be close to those of practical experiments and had a good correlation with the actual burst pressure.