QI1L4BF Comparison of Direct Assessment to Other Pipeline Integrity Assessment Methods

Abstract

The purpose of this project is to compare the attributes of three pipeline integrity assessment methods: direct assessment, hydrostatic testing, and in-line inspection. Technical Perspective: In conjunction with on-going work by others to establish methods for conducting direct assessments and to establish the reliability of those assessments, this report shows how the evolution of direct assessment has brought it to a level that makes it comparable to other pipeline integrity assessment methods. Technical Approach: The benefits and limitations of hydrostatic testing, in-line inspection, and external corrosion direct assessment are discussed. The report points out how the work by others on external corrosion direct assessment leads to a calculable level of the probability of a failure after such an assessment. The other methods of pipeline integrity assessment, hydrostatic testing, and in-line inspection also assure a maximum probability of failure. The probability of failure becomes the basis for comparisons between any two or all three methods.