The hardness values of weldments of supermartensitic stainless steels exceed limits for “sour service” and testing has to be done. Most testing has been done by procedure defined in EFC Publication No 172. Some observations during testing have led to a discussion on the relevance of the test methods and procedures.
A corrosion cracking assessment evaluated a 13Cr-5Ni-2Mo 110 ksi grade martensitic stainless steel as a potential well tubing material for oil and gas production from Gulf of Mexico reservoirs. Also, Stress Corrosion Cracking at low H2S/low temp/high acidity (pH<3.5) was tested by Cyclic Slow Strain Rate.
The purpose of this paper is to illustrate the possibility of testing full sized connections in sour environments. It is also intended to demonstrate to the industry that the pipe body is possibly more susceptible to cracking than is the premium connection fabricated from the same susceptible material.
The aim of this test program is to provide technical data to support the replacement of austenitic flexible pipe carcass, at Campos Basin, by low cost materials with suitable mechanical properties and corrosion resistance when the field conditions turn too aggressive to carcass materials in operation.