Drilling and Production Flashcards
7 cards from real API 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 and Production flashcards as text
What is 'underbalanced drilling' (UBD)?
Answer: Drilling with wellbore pressure intentionally lower than formation pore pressure
Underbalanced drilling maintains wellbore pressure below formation pressure, allowing formation fluids to flow into the wellbore in a controlled manner.
In production engineering, what is the 'tubing performance relationship' (TPR)?
Answer: A curve relating bottom-hole pressure to surface tubing pressure during production
The TPR (also called vertical lift performance or VLP) describes how bottom-hole flowing pressure varies with production rate for a given tubing string.
What is 'lost circulation' in drilling and how is it typically addressed?
Answer: Loss of drilling fluid into the formation, addressed by adding lost circulation material (LCM) to the mud
Lost circulation occurs when drilling fluid flows into natural fractures or vugular formations; it is treated by adding fibrous, flaky, or granular LCM to plug the openings.
What does API gravity measure in petroleum classification?
Answer: The density of crude oil relative to water, where higher values indicate lighter oil
API gravity is an inverse measure of crude oil density; values above 10 float on water, with higher API gravity indicating lighter, more valuable crude.
In drilling, what is the purpose of 'drill collars' in the bottom hole assembly (BHA)?
Answer: To provide weight on bit and stiffen the lower drill string
Drill collars are heavy, thick-walled tubulars placed above the bit to provide the necessary weight on bit while keeping the drill string in tension.
What is the 'Christmas tree' on a producing oil well?
Answer: An assembly of valves, spools, and fittings at the wellhead to control production flow
The Christmas tree is the surface assembly of valves and controls installed on the wellhead to regulate and monitor oil and gas production.
According to API standards, what is the minimum number of barrier envelopes required to prevent uncontrolled flow in a well during production?
Answer: Two
API and industry well control standards require a minimum of two independent barrier envelopes to prevent uncontrolled flow of reservoir fluids to surface or environment.