Drilling & Production Techniques Flashcards

What is the primary purpose of a blowout preventer (BOP) stack on a drilling rig?

Answer: To seal the wellbore and prevent uncontrolled flow of formation fluids

A BOP stack is a series of valves installed at the wellhead to seal the wellbore and prevent blowouts caused by unexpected formation pressure.

Which drilling method uses a continuous steel tube wound on a reel instead of individual drill pipe joints?

Answer: Coiled tubing drilling

Coiled tubing drilling uses a continuous flexible steel tube that is unwound from a large reel and inserted into the wellbore without connections.

What does 'WOB' stand for in drilling operations?

Answer: Weight On Bit

WOB (Weight On Bit) is the downward force applied to the drill bit by the drill collars, which is critical for efficient penetration of formation rock.

In directional drilling, what instrument measures the wellbore's inclination and azimuth?

Answer: Measurement While Drilling (MWD) tool

MWD tools transmit real-time wellbore inclination and azimuth data to the surface while drilling, enabling directional control.

What is a 'kick' in drilling terminology?

Answer: Unplanned influx of formation fluid into the wellbore

A kick occurs when formation fluid (gas, oil, or water) enters the wellbore because formation pressure exceeds hydrostatic pressure of the drilling fluid.

Which type of well completion allows reservoir fluids to flow through perforations in the casing?

Answer: Cased-hole perforated completion

In a cased-hole perforated completion, shaped charges create holes through the casing and cement to connect the reservoir to the wellbore.

What is the function of drill collars in a bottom hole assembly (BHA)?

Answer: To provide weight on bit and keep the drill string in tension

Drill collars are heavy-walled steel tubes that provide the necessary weight on bit while keeping the drill pipe above them in tension to prevent buckling.