scope:

Foreword

a. This recommended practice is under the jurisdiction of the API Committee on Standardization of Tubular Goods.

NOTE: No provision of this recommended practice shall be cause for rejection of casing or tubing provided the threads are in accordance with the requirements of API Std 5B.

b. The statements on corrosion of casing and tubing as given herein, were developed with the cooperation of the Technical Practices Committee on Corrosion of Oil and Gas Well Equipment, National Association of Corrosion Engineers.

c. It is suggested that the selection of a thread compound for casing and tubing be given careful consideration by the user, bearing in min that a satisfactory compound should possess certain properties, the major of which are (1) to lubricate the thread surfaces to facilitate joint make-up and break-out without galling, and (2) to seal voids between the mating thread surfaces and effectively prevent leakage. Compounds which have given outstanding service for casing and tubing under both laboratory and field conditions are described in API Bul 5A2: Bulletin on Thread Compounds.

d. The selection of a thread compound for use on rotary shouldered connections should also be given careful consideration to insure adequate protection against galling and excessive make-up. Compounds that have proven satisfactory are described in API Std 7: Specification for Rotary Drilling Equipment. Users are cautioned that thread compounds described in API Bul 5A2 should not be used on rotary shouldered connections.

e. Some generalized suggestions on prevention of damage to casing, tubing, and drill pipe by corrosive fluids are given herein (Par. 1.30-p, 2.34-o, and 5.1.) It is not, however, within the scope of this bulletin to provide detailed suggestions for corrosion control under specific conditions. Many variables may be involved in a specific corrosion problem and interrelated in such a complex fashion as to require detailed attention to the specific problem. For more complete technical information on specific corrosion problems, the user should consult the official publication of the National Association of Corrosion Engineers, CORROSION, or Corrosion of Oil and Gas Well Equipment, T-1, NACE, 2400 West Loop South, Houston, Texas 77027.