The sudden, unexpected increase in mud pit volume that serves as the most reliable surface indicator of a kick.
What is a pit gain?
The first line of defense in well control, maintained by the weight of the drilling fluid.
What is Primary Well Control?
The shut-in procedure where the choke is kept closed during the initial closure of the BOP.
What is a Hard Shut-In?
The well kill method where the kick is circulated out while simultaneously pumping heavy kill mud in a single continuous circulation.
What is the Engineer's Method (Wait and Weight Method)?
The large vertical conduit connecting a subsea blowout preventer (BOP) on the seafloor to the floating drilling rig.
What is a Marine Drilling Riser?
The flow status where fluid flowing out of the well is greater than fluid being pumped in.
What is positive flow (gain in flow rate)?
Equipment used to contain and manage pressure when primary well control fails and a kick enters the wellbore.
What is secondary Secondary Well Control (or BOP stack)?
Abbreviated as SIDPP, this surface reading indicates the difference between formation pressure and the hydrostatic pressure inside the drill pipe.
What is Shut-In Drill Pipe Pressure?
The well kill method where the influx is immediately pumped out using existing mud, followed by pumping heavy mud in a second circulation.
What is the Driller's Method?
The component in a subsea BOP stack designed to shear through drill pipe and seal the wellbore in an extreme emergency.
What is a Blind Shear Ram (BSR)?
This phenomenon occurs when drilling into a formation where the fluid pressure exceeds the hydrostatic pressure of the mud column.
What is an underbalanced condition?
The hydrostatic pressure exerted by a mud column depends on these two primary factors.
What are Mud Density (weight) and True Vertical Depth (TVD)?
Abbreviated as SICP, this surface reading is typically higher than SIDPP because the influx in the annulus is less dense than the mud.
What is Shut-In Casing Pressure?
The non-conventional well control technique used to bleed off gas hicks when pipe is off bottom or circulation is impossible.
What is Volumetric Method (Lubricate and Bleed)?
The phenomenon in floating rigs where vessel vertical motion affects downhole pressures, pit levels and slip joint stroke.
What is Rig Heave?
Drilling faster than normal due to a decrease in rock strength and mud weight differential-often an early warning sign of transitioning into over pressured zone.
What is a drilling break?
The term for pressure lost due to fluid friction as mud moves through the drill string, bit and annulus.
What is Annular Pressure Loss (Dynamic Pressure Lost)?
The pressure test conducted below the casing shoe to determine the maximum pressure the formation can withstand before fracturing.
What is a Leak-Off Test (LOT)?
During a well kill operation using the Driller's or Engineer's method, this parameter on the choke panel must be kept constant while adjusting the choke at constant pump speed.
What is Drill Pipe Pressure (Circulation Pressure)?
Lines wrapped around the outside of a marine riser that connect the subsea BOP to the surface choke manifold.
What are Choke and Kill lines?
The influx fluid type that results in the highest shut-in drill pipe pressure (SIDPP) and fastest surface pressure build-up due to gas expansion.
What is natural gas (or a gas kick)?
The total effective pressure exerted on the formation while circulating mud, accounting for hydrostatic pressure and friction loss.
What is Equivalent Circulating Density (ECD)?
The maximum pressure that can be safely applied at the casing seat or surface choke without inducing formation fracture.
What is Maximum Allowable Annular Surface Pressure (MAASP)?
The pressure required to overcome static friction and system resistance when restarting circulation during a well kill, requiring careful choke adjustment to avoid over pressuring the formation.
What is Initial Circulating Pressure (ICP)?
Trapped gas under a subsea BOP stack that must bee safely removed after a well kill to avoid a secondary kick when opening the rams.
What is Gas trapped under the BOP (Trapped Gas Bleed-off protocol)?