Changes

Bottoms-up circulation, or ''lag time'', is the time for samples or gas created at the bit to arrive at the surface (via the drilling fluid) for examination. This calculation is dependent on the volume and rate.

Bottoms-up circulation, or ''lag time'', is the time for samples or gas created at the bit to arrive at the surface (via the drilling fluid) for examination. This calculation is dependent on the volume and rate.

After calculating wellbore volumes and mud pump output, several parameters for the circulating time of the drilling fluid can be estimated. The most routinely used of these parameters are

After calculating wellbore volumes and mud pump output, several parameters for the circulating time of the [[drilling fluid]] can be estimated. The most routinely used of these parameters are

* surface-to-bit pump strokes,

* surface-to-bit pump strokes,