The Importance of Hardness Requirement in Producing Pipes and Weldments for Drilling Riser P-Lines

Introduction

The question pertains to item A.2.2.3.3 of ISO 15156-2 and whether the relaxation of the hardness requirement from HRC 22 to HRC 26 would be helpful in producing pipes and weldments using AISI 4130 tubes in the quenched and tempered condition for drilling riser P-lines (choke, kill, and booster lines).

Applicability of Paragraph A.2.2.3.3 of ISO 15156-2

The answer is that Paragraph A.2.2.3.3 of ISO 15156-2 is applicable to downhole casing, tubing, and tubular components used in region 3 of the diagram in Paragraph 7.2. Materials for P-lines in drilling risers are not included in Paragraph A.2.2.3.3, and the materials for P-lines used in Region 3 are hardness-limited to HRC 22.

The Valid Point Raised by the Inquiry

However, the inquiry raises a valid point about Inquiry 2005-23 since testing according to Table B.1 in Annex B is an accepted qualification method. Testing can be used to qualify any material/application (including 4130/P-lines in drilling risers) provided it is performed according to ISO 15156 requirements.

Conclusion

This inquiry regards NACE MR0175/ISO 15156-2 Annex A.2.2.2 and A.2.2.3. Reference: ISO 15156 Maintenance Panel Inquiry #2010-04.