Production Operations & Optimization 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 Production Operations & Optimization flashcards as text
Which dimensionless number is used to determine the onset of critical (sonic) flow through a wellhead choke?
Answer: Mach number equal to 1 at the choke throat
Critical flow through a choke occurs when the flow velocity at the choke throat reaches the speed of sound (Mach 1), making downstream pressure changes unable to affect upstream flow rate.
A production engineer wants to reduce water production from a bottom-water drive reservoir. Which completion strategy is most effective?
Answer: Perforate at the top of the oil column and set a packer above the water zone
Perforating at the top of the oil column with a packer above water maximizes the standoff distance from the oil-water contact, delaying water coning.
What is the function of a production packer in a single-zone completion?
Answer: To prevent fluid migration between the tubing-casing annulus and the producing zone
A production packer isolates the tubing-casing annulus from the producing zone, directing reservoir fluids up the tubing and protecting the casing from produced fluids.
In multiphase flow through tubing, which flow regime typically results in the highest pressure drop per unit length?
Answer: Slug flow
Slug flow produces large, intermittent liquid slugs that cause significant pressure fluctuations and generally the highest average pressure gradient in vertical tubing.
When applying decline curve analysis, an exponential decline indicates which condition about the producing reservoir?
Answer: The production rate decline is proportional to the current rate with a constant decline rate
Exponential decline occurs when the rate of rate-decline is constant and proportional to the current rate, typically seen under boundary-dominated flow with constant BHP.
A well's flowing wellhead pressure suddenly drops to near zero while the flow rate remains stable. What is the most likely cause?
Answer: Choke washout increasing effective choke diameter
A washed-out choke has an enlarged orifice that reduces backpressure while maintaining or increasing flow rate, causing WHP to drop significantly.
Which method is used to estimate the skin factor from a pressure buildup test using the Horner plot?
Answer: Calculate skin from the difference between extrapolated p* and the actual flowing BHP at shut-in
Skin is calculated by comparing the extrapolated static pressure (p*) to the actual flowing BHP before shut-in using the standard van Everdingen-Hurst skin equation applied to the Horner straight line.