Well Control & Blowout Prevention Flashcards

Which type of BOP ram can close and seal the wellbore around any size of drill pipe or even on an open hole?

Answer: Annular preventer (Spherical BOP)

The annular preventer (also called a spherical BOP) uses a donut-shaped rubber packing element that can seal around any size of drill pipe, kelly, or open hole by compressing inward.

What is the 'kill line' on a BOP stack used for?

Answer: To circulate heavy mud into the wellbore from the surface to kill the well

The kill line connects the mud pumps to the BOP stack below the pipe rams, allowing heavy kill-weight mud to be pumped into the wellbore to overcome formation pressure and kill the well.

What does Shut-In Drill Pipe Pressure (SIDPP) indicate?

Answer: The formation pore pressure minus the hydrostatic pressure of the mud in the drill string

SIDPP represents the difference between formation pore pressure and the hydrostatic pressure of the mud inside the drill string, and is used to calculate the kill mud weight needed.

What is the primary function of the choke manifold in well control operations?

Answer: To control annular back pressure while circulating a kick out of the well

The choke manifold allows the driller to maintain back pressure on the annulus while circulating a kick out, preventing additional formation fluid influx while keeping the bottom hole pressure constant.

What does 'gas-cut mud' returning at surface indicate?

Answer: Formation gas has contaminated the drilling fluid, reducing its density

Gas-cut mud occurs when formation gas enters the drilling fluid and becomes entrained in it, significantly reducing the mud density and potentially leading to reduced bottom hole pressure and a kick.

What is the purpose of a float valve (check valve) installed in the drill string?

Answer: To prevent formation fluids from flowing up through the inside of the drill string

A float valve is a one-way check valve in the drill string that allows mud to be pumped downward but prevents backflow of formation fluids up through the drill string interior.

What is 'Shut-In Casing Pressure' (SICP) used to determine during a well kick?

Answer: The pressure and composition of the formation fluid that has entered the wellbore

SICP, measured at the casing side after shut-in, helps determine the nature and density of the kick fluid (gas is lighter and gives higher SICP relative to SIDPP, while saltwater gives nearly equal pressures).