Drilling & Well Completion Flashcards
7 cards from real SPE practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 7 Drilling & Well Completion flashcards as text
What is the primary purpose of a diverter system installed at the wellhead during top-hole drilling?
Answer: Divert shallow gas flows away from the rig floor to protect personnel
Diverter systems redirect unexpected shallow gas influxes away from the rig floor, protecting personnel since BOPs are not yet installed.
In a horizontal well, what is the primary function of a rotary steerable system (RSS)?
Answer: Provide continuous rotation while steering the bit to the target trajectory
An RSS allows the drillstring to rotate continuously while a steering mechanism deflects the bit toward the planned trajectory.
Which cement slurry additive is used to prevent gas migration through unset cement?
Answer: Expanding agent or anti-gas migration additive
Anti-gas migration additives (e.g., expanding agents or latex) reduce cement permeability and control gel strength development to block gas channels.
What does the term 'equivalent circulating density' (ECD) represent in drilling operations?
Answer: The effective mud weight at a given depth accounting for annular friction pressure losses
ECD equals static mud weight plus the additional pressure from annular friction losses, expressed as an equivalent fluid density at depth.
A perforating gun is fired with an underbalanced condition. What is the main benefit of underbalanced perforating?
Answer: Creates immediate inflow that cleans perforation tunnels of crushed zone debris
Underbalanced perforating draws formation fluids into the wellbore immediately upon firing, cleaning crushed zone damage from the perforation tunnels.
Which well control method involves pumping a heavier kill fluid down the drillpipe while holding constant casing pressure?
Answer: Wait-and-weight (engineer's) method
The wait-and-weight method mixes kill-weight mud before pumping, circulating it in one continuous cycle while holding constant casing pressure.
What is the purpose of a packer in a production completion?
Answer: Isolate the tubing-casing annulus to direct production through the tubing
A packer seals the annulus between the tubing and casing, forcing production fluids up the tubing and protecting the casing from wellbore pressures.