Method and apparatus for compensating for drilling line stretch in determining equipment depth in a well and for measurement of hookload on the traveling block of a drilling rig

摘要

An arrangement for measuring the stretch of a wire line used in well drilling operations by first measuring the amount of stretch in the deadline by measuring rotation of the dead sheave which supports the deadline, and multiplying the length of the wire line by the ratio of the amount of elastic stretch in the deadline to the length of the deadline. Equipment depth in the well is determined by measuring the movement of the wire line and applying a correction for the wire line stretch. If desired, a correction can also be applied for any errors in the split block separation. The ratio of the amount of stretch in the deadline to the length of the deadline may be employed to provide measurement of the hookload on the traveling block.