250+ TOP MCQs on Well Testing – Transient Pressure Tests and Answers

Petroleum Production Operations Multiple Choice Questions on “Well Testing – Transient Pressure Tests”.

1. For Pseudo- Steady state flow which of the following is correct in which P,t represents Pressure and time respectively?
a) dP/dt =0
b) dP/dt =constant
c) dP/dt =infinity
d) dP/dt =1
View Answer

Answer: d
Clarification: For Pseudo- Steady state flow partial derivative of pressure with respect to time is constant not zero i.e. mathematically dP/dt =constant. Pseudo- Steady state flow is also known as semi-steady-state flow and quasi-steady state flow.

2. What is the type of fluid flow state showing on the diagram below?

a) Steady state flow
b) Unsteady state flow
c) Semi-steady state flow
d) Vertical flow
Answer: c
Clarification: The type of fluid flow state showing on the diagram is of Semi-steady sate flow which is also known as Pseudo- Steady state flow and quasi-steady state flow.

3. How can be the pressure drop across the _skin is calculated (all signs have their original meanings)?
a) ΔP_skin= 141.2qμBs/kh
b) ΔP_skin=141.2qkh/μBs
c) ΔP_skin=141.2qμks/Bh
d) ΔP_skin=162.2qμBs/kh
View Answer

Answer: a
Clarification: The pressure drop across the ΔP_skin is calculated by using the formula ΔP_skin= 141.2qμBs/kh. Where ΔP_skin is the pressure drop across the ΔP_skin. B is the formation volume factor, μ is the viscosity, s is the dimensionless _skin factor, k is the permeability and h is the height.

4. Damage Ratio is the inverse of the Flow efficiency.
a) True
b) False
Answer: a
Clarification: Yes, Damage Ratio is the inverse of the Flow efficiency. Flow efficiency can be calculated by using the formula Damage Ratio=J_ideal/J_actual. Where J_ideal stands for productivity index under ideal conditions and J_actual stands for productivity index under actual condition.

5. Which of the following is Miller- Dyes- Hutchinson equation?
a) P_ws = P_i – (162.6qμB/kh)* log((t_p + Δt)/Δt)
b) P_ws = P_i – (141.2qμB/kh)* log((t_p + Δt)/Δt)
c) P_ws = P_1hr + (162.6qμB/kh).log(Δt)
d) P_ws = P_1hr + (141.2qμB/kh).log(Δt)
Answer: b
Clarification: The Cloud Miller- Dyes- Hutchinson equation is P_ws = P_1hr + (162.6qμB/kh).log(Δt). MDH methods is usually easier to use hence it is used frequently but in the case of Drill Stem Testing where the flow time magnitude is almost equal to the flow time this method is not used. For that case we generally use the Horner’s plot.

6. Which of the following are not the benefits of the Pressure Drawdown test over the Pressure Build up test?
a) Production continues during the test period
b) Reservoir volume in communication with the wellbore can be estimated
c) Production continues during the test period as well as Reservoir volume in communication with the wellbore
d) Production ceases during the test period
Answer: d
Clarification: The correct answer is Production ceases during the test period. The benefits of the Pressure Drawdown test over the Pressure Build up test are Production continues during the test period, Reservoir volume in communication with the wellbore can be estimated along with the formation damage and formation permeability.