Definition - What does Mud Loss mean?
Mud loss, also known as lost circulation, can be defined as the loss of drilling mud to the formation during drilling operations. Mud loss is noticed when there is a lack of drilling mud returning to the surface after it has been pumped down a well.
Mud loss is frequently encountered while drilling and happens when the mud weight essential to maintain wellbore stability and well control exceeds the fracture resistance of the formation, especially in depleted reservoirs.
Trenchlesspedia explains Mud Loss
Mud loss occurs when the drill bit encounters fractures or natural fissures in the formation and mud flows into it, uncontrolled. It can also happen due to improper drilling conditions, excessive downhole pressure or when the intermediate casing is set too high. Lost circulation can be addressed by conducting preventive tests such as leakoff test (LOT) and formation integrity test (FIT).
Lost circulation can be costly and reduce the ability of the operator to produce from that zone. When mud loss occurs, it is necessary to seal the zone by using loss of circulation materials (LCM) such as fibrous, flaked or granular material mixed with the mud.