SY/T 6857.2-2012 in English

Scope

This part specifies the technical performance index system of steel drill pipe for drilling in an acidic environment containing hydrogen sulfide. A acidic environment containing hydrogen sulfide refers to a fluid containing liquid water and HS exceeding a certain limit value [acid gas refers to a gas with a total pressure greater than or equal to 0.4MPa (65psi), and a HS partial pressure greater than 300Pa (0.05psi)]. This part defaults to the same provisions as API Spec 5DP:2009 and API Spec 7-2 for drill pipe outer diameter, wall thickness, thickened transition zone size, thread parameters and other structural parameters. For non-API drill pipe specifications, the specific parameters are determined by negotiation between the supply and demand parties. The products involved in this part are divided into two categories: a) SS drill pipe, which is suitable for drilling projects where the drilling fluid column pressure is not lower than the formation pressure. Its product identification is "SS+steel grade (ksi)", and the matching joint identification is "SS+steel grade (ksi) + TJ". The steel grade in the identification indicates the yield strength of the pipe body or joint material. b) SU drill pipe is suitable for underbalanced drilling projects where the drilling fluid column pressure is lower than the formation pressure. Its product identification is "SU+steel grade (ksi)", and the matching joint identification is "SU+steel grade (ksi)+TJ". The steel grade in the identification indicates the yield strength of the pipe body or joint material.