Strength Assessment of a Corroded Pipeline through the Burst Test: Case Study

Abstract

Failure due to corrosion has become one of the major problems in maintaining pipeline integrity. Smart pigs have been used for decades to assess the in situ condition of steel pipe serving the oil and gas industries. The assessment techniques used are generally described in standards prepared by American Petroleum Institute (API) and American Society for Testing and Materials (ASTM). These standards are viewed by some in the industry as being conservative, resulting in premature repair or replacement of pipelines. Therefore, pipeline operators need better, more reliable condition assessment tools, not only to assure safe operations, but also to optimize maintenance costs. That is to repair or replace only the pipe sections that need the remediation. Recently, an alternative condition assessment method was developed using finite element (FE) analyses that were validated through actual pipe burst tests results. In this paper, the burst test procedure and results of testing a 250-mm (10-in.) nominal diameter API X52 pipe sections are presented. The experiments consisted of an exhumed pipe section with internal corrosion and additional sections with simulated corrosion defects. Details of the pipe and corrosion geometry, material properties, and the conditions surrounding each failure location were recorded.