Drilling Engineering Principles 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 Engineering Principles flashcards as text
What is the significance of the 'fracture gradient' when designing a drilling program?
Answer: It defines the maximum mud weight that can be used without fracturing and losing fluid to the formation
The fracture gradient sets the upper limit on equivalent circulating density; exceeding it causes induced fractures that lead to lost circulation and potential well control problems.
Which of the following best describes the role of 'stabilizers' in a bottom hole assembly (BHA)?
Answer: To centralize the BHA in the wellbore and control bit trajectory
Stabilizers contact the wellbore wall to centralize the BHA, control wellbore trajectory tendency, and reduce vibration and lateral movement of the drill string.
What is 'differential sticking' and what conditions make it likely to occur?
Answer: The drill string becoming embedded in a permeable formation due to the pressure difference between mud and formation, typically when the string is stationary
Differential sticking occurs when the drill string is held against a permeable formation by the net force from overbalance pressure acting over the contact area, especially during static conditions.
In hydraulics design, what is the purpose of optimizing bit hydraulics?
Answer: To maximize the cleaning of cuttings from beneath the drill bit and optimize jet velocity or hydraulic horsepower at the bit
Optimizing bit hydraulics maximizes the energy delivered to the bit face to efficiently clean cuttings and cool the bit, typically by optimizing nozzle size selection.
What is the primary purpose of 'conductor casing' in a well?
Answer: To prevent shallow blowouts, support subsequent casing strings, and provide a foundation for the wellhead
Conductor casing is the first casing string set to prevent shallow formation collapse, support the wellhead and subsequent casing strings, and provide a conduit for returns.
Which drilling problem is best identified by observing 'overpull' on the drill string when picking up off bottom?
Answer: A tight hole or mechanical sticking condition
Overpull — requiring more hookload than expected to move the drill string — indicates a tight hole, ledge, key seat, or other mechanical obstruction causing the string to hang up.
What is the function of the 'choke manifold' in a well control system?
Answer: To control wellbore back-pressure during well control operations by restricting flow through adjustable chokes
The choke manifold allows the driller to maintain back-pressure on the wellbore while circulating out a kick, controlling annular pressure to prevent formation fracture or additional influx.