Definition
Kick — A kick is an unwanted influx of formation fluid — oil, gas or water — into the wellbore that occurs when the pressure in the well falls below the formation pressure, and if not controlled it can escalate into a blowout.
Also known as: kick, well kick, influx
What a kick is
A kick occurs when formation fluids enter the wellbore because bottomhole pressure has dropped below formation pore pressure. Common causes include insufficient mud weight, failure to keep the hole full while tripping (swabbing), lost circulation, and drilling into an abnormally pressured zone. A gas kick is especially hazardous because gas expands as it rises, further reducing hydrostatic head and accelerating the influx.
Kicks are detected at surface through warning signs such as a pit-volume gain, an increase in flow-out with pumps constant, a drilling break, or the well flowing with pumps off. Prompt detection is the key to shutting in before the influx grows.
Responding to a kick
Once a kick is recognized, the crew shuts in the well on the BOP, records the shut-in drillpipe and casing pressures, and calculates the kill mud weight. The influx is then circulated out using a controlled method that holds bottomhole pressure at or above formation pressure to prevent further influx.
Why it matters for rentals
Controlling a kick relies on certified drill-string barriers working with the surface BOP. Rental inside BOPs, full-opening safety valves and dart valves must be pressure tested and matched to the well’s pressure. See our pressure control equipment and well control application, or contact us.