Complex analysis of collapse strength for tubulars used in the oil and gas industry

Oilfield Country Tubular goods are an important component in the oil and gas industry. Tubing is generally used for the production phase of a well, especially for gas wells. The integrity of tubing is critical for a safe and correct functioning of different installations in the oil and gas industry, and possible malfunctions can incur substantial financial or environmental problems. In these circumstances an exact appreciation of the tubing resistance is of paramount importance. The method that produces the most exact results is the collapse pressure test, but it is expensive and time consuming. Therefore, the authors propose a different approach in the sense that a Finite Element Analysis (FEA) could, if carefully performed, produce a reliable result for the assessment of the collapse pressure for tubing. In this paper, a quadruple analysis is proposed: a collapse pressure test, a geometric measuring (3D scanning) of the deformed (collapsed) pipe segment, an analytical calculation of the collapse pressure and a finite element analysis for a pipe segment. The results obtained will be compared and will allow the authors to evaluate and value the FEA, as a cheaper and rapid approach in assessment of the collapse pressure resistance for tubing.