American Petroleum Institute

Techniques for Sizing Imperfections in  Tubular Goods
 N REPORT 95-83

Annotation

INTRODUCTION

This project was sponsored by the American Petroleum Institute (API) under agenda item #1043, and assigned as API Project 95-83. The Technical Advisory Committee for project 95-83 is listed in Table 1. The objective of the project is to examine nondestructive test (NDT) imperfection sizing methods applicable to API tubular goods. This objective is further defined to include sizing of the radial extent of inside diameter (ID) imperfections in the "prove-up" stage of tubular manufacture. Prove-up inspections are conducted after tubular imperfections have been located by full body NDT and are generally conducted at the tubular mill, but inspection at the user site by third party testing is not uncommon.

The project was conducted in two phases. The first phase consisted of a feasibility assessment of nondestructive sizing methods, and included a brief round robin test series using machined notches in flat plates. Phase I concluded with submission of a TRI/ Austin technical report, and is summarized in Appendix A (also see bibliography for report reference). The goals of the Phase TI portion of the project included:

1. Collect a set of API Tubular mill rejected specimens for imperfection depth measurement testing and method documentation

2. Conduct a round robin test series, using the API Tubulars specimen set, with technologist measuring the maximum radial extent of imperfections

3. Destructively analyze/measure imperfection radial depth in the API Tubulars specimen set

4. Analyze data and document NDT methods, applicable standards, training and NDT equipment costs

5. Recommend imperfection depth measurement technologies and directions for further development in API Tubulars to the API TAC.