Explain what it means to "Drift" and "Tally" the casing.

Answer and Explanation:

The drift and tally of casing is mainly used in oil rings. The drift is a simple tool which is mainly used for measuring the inside size of the casing after the drilling process. Drift are mainly available in casing drift and turbine drift. The laser and m, annual methods are used for tally which is more quick and accurate. these two methods are done to increase the productivity of the casing