Fluid loss and gain for flow, managed pressure and underbalanced drilling

摘要

A method for monitoring a well bore during drilling operations, particularly with respect to a fluid gain and/or fluid loss event. Monitoring the well bore may be accomplished by monitoring an incoming flow rate of the fluid into the wellbore. The fluid return line from the well bore may carry drilling fluid from the well bore to a mud gas separator located downstream from the well bore. Changes in at least one parameter of the mud gas separator may be monitored. The changes to the at least one parameter of a mud gas separator may be compared to the incoming flow rate of the fluid. Discrepancies between the changes and the incoming flow rate may be indicative of a fluid gain or fluid loss condition.