Collapse and Post Collapse Behaviour of Tubulars: a simple approach

This paper describes a simple method of evaluating the collapse strength and post collapse behavior of oil field tubulars subjected to external pressure. The method is based on elastic ovalization and subsequent plastic collapse by formation of a four-hinge mechanism. The resulting predictions of collapse strength are compared with available collapse test data, and other existing collapse equations. For post collapse behavior, model predictions are compared with available experimental and numerical data. Applications of the method to collapse of perforated and slotted liners, prepacked screens and collapse under non-uniform loading are described.