Guidelines on materials requirements for carbon and low alloy steels for H2S-containing environments in oil and gas production (EFC 16) 3rd Edition PDF

This document provides guidelines on the materials requirements for the safe application of carbon and low alloy steels typically used in H2S-containing environments in oil and gas production systems. It does not include refinery operations.

A description is given of the types of cracking which can arise in wet H₂Scontaining environments.

A systematic approach to the definition of sour service in relation to sulphide stress cracking is presented for Oil Country Tubular Goods up to strength level PllO, i.e. high strength low alloy steels with homogeneous microstructure. The same methodology can be applied to other grades of steels and welded steels and these may follow similar trends, however, their precise environmental limits are still being established.

Guidelines are given on materials requirements to prevent sulphide stress cracking, stepwise cracking, stress oriented hydrogen induced cracking and soft zone cracking in steels in various product forms. The guidelines do not include requirements for avoiding other forms of corrosion, hydrogen embrittlement or other forms of cracking (e.g. stress corrosion cracking, corrosion fatigue, etc.) that can occur in the absence of H₂S.

Guidelines for materials requirements for corrosion resistant alloys in H2Scontaining environments are covered in EFC17.

Comprehensive guidance is given on procedures for sulphide stress cracking and stepwise cracking testing including suggested acceptance criteria for the various test methods.

Graphs are included for the approximate determination of pH in producing systems.

Recommendations are made on appropriate methods for hardness testing of components and weld zones for service in H2S-containing environments.