The Development of Risk-Based Burst Design for Well Casing and Tubing

Abstract

Abstract This paper reports on the development of a risk-based burst design method. A criterion is developed so that ductile materials can be identified. The results for an experimental and analytical burst pressure study are combined with a large body of data for tubular dimensions and material properties. Statistical measures were obtained for all the data and a reliability study was performed on the design equations developed. This reliability study investigated: The relationships between probability of failure the design factor used in the design.The relationship between material grade and the probability of failure.The effect of axial tension on the probability of failure.The effect of flaw frequency on the probability of failure of a well string.The effect of D/T ratio on failure probability. The methods developed can be used to estimate the probability of failure for well casing and tubing under any given combination of pressure and axial loads.