This invention relates to the identification of drill pipe sections employed in a drill string of a borehole drilling system.
In borehole drilling operations, it is desirable to keep track of the position of the drill pipe sections in a drill string and to obtain a record of the service time of each drill pipe section for the purpose of determining fatigue damage. Such information is particularly useful by the contractor in determining the dollar value of the damage occuring to the pipe in drilling a given well and to determine when to downgrade or retire the pipe from service. It is possible to obtain and record this information manually, however, such a technique is time consuming and subject to error.
In a new identification process and system, numbers in binary form, comprising apertures filled with a non-magnetic material, are formed in the outer walls of the drill pipe sections. The numbers are read by a sensor comprising an encircling electrical coil and a detecting element which is rotated around the drill pipe sections as they are moved through the encircling coil.