A thorough inspection process of drilling tubulars is required to be sure they meet the criteria for the job and is vital for maintaining the flow of operation. Inspection can help foresee any future problems before damage to the tubulars becomes critical, thus preventing costly repair bills, environmental damage and most importantly, injury to personnel. In this post we’re going to look at some of the standards, methods and techniques used in the inspection process. Reliability of inspection process depends on standards. These are used to ensure reproducible results during the drill pipe inspection and also helps us compare results and make decisions on acceptance/rejection. Ensuring all figures, dimensions and tolerances are complied to within these requirements is an important factor in assuring the tubulars are fit for use.

Globally, some inspection standards apply depending on customer requirements in different drilling areas. These include:
· API RP 7G/2: Recommended practice for Inspection and Classification of used Drill Stem Elements
· DS-1 Volume 3: Drill Stem Inspection
· NS-2 Drillstring Inspection Standard

API tubing is inspected at the mill in accordance with API Spec. 5CT. Physical properties are checked and each length hydrostatically tested, normally to only 3,000 psi in the plain end (unthreaded) condition. The following are also checked:
· Dimensions
· Weights
· Straightness
· Lengths

Inspection methods
There are several types of tubing inspection methods that may be beneficial. The common methods of inspecting the tubing currently in use in field operation are:
· Visual
· Calipers
· Hydrostatic
· Electromagnetic
· Magnetic particle
· Ultrasonic