Question:
Which of the following option(s) is/are CORRECT for well testing analysis of a reservoir?
Which of the following option(s) is/are CORRECT for well testing analysis of a reservoir?
Show Hint
In well testing:
\textbf{Transient (IARF)} $\Rightarrow$ estimate \textbf{permeability and skin}.
\textbf{Late-time / pseudo-steady (boundary-dominated)} $\Rightarrow$ infer \textbf{reservoir geometry / boundaries}.
For gas wells, \textbf{back pressure (deliverability) tests} $\Rightarrow$ \textbf{AOFP}.
\textbf{Late-time / pseudo-steady (boundary-dominated)} $\Rightarrow$ infer \textbf{reservoir geometry / boundaries}.
For gas wells, \textbf{back pressure (deliverability) tests} $\Rightarrow$ \textbf{AOFP}.
Updated On: Feb 9, 2026
- Permeability, skin and reservoir geometry are calculated using data from pseudo steady state.
- Permeability, skin and reservoir geometry are calculated using data from transient state.
- Reservoir geometry is calculated using data from pseudo steady state.
- Absolute open flow potential is calculated from back pressure test for a gas well.
Hide Solution
Verified By Collegedunia
The Correct Option is C
Solution and Explanation
Step 1: Identify what is obtained from transient (infinite-acting) data.
In well testing, the transient (infinite-acting radial flow) period is primarily used to estimate:
Permeability ($k$) from the semilog slope, and
Skin ($s$) from the semilog intercept (or equivalent transient relationships).
Hence, $k$ and $s$ are transient-state estimates, not pseudo-steady-state estimates.
Step 2: Identify what is obtained from pseudo-steady-state / boundary-dominated flow.
When the pressure response becomes boundary-dominated (pseudo-steady-state in closed/drainage systems),
the data reflect reservoir size/geometry effects (e.g., drainage area, boundaries).
Thus, reservoir geometry is commonly inferred from pseudo-steady-state / late-time behavior.
So, statement (C) is correct.
Step 3: Evaluate Absolute Open Flow Potential (AOFP) statement.
For a gas well, back pressure (deliverability) tests are used to determine the deliverability equation and estimate
the absolute open flow potential (AOFP) (rate at $p_{wf} \to 0$) by extrapolation.
So, statement (D) is correct.
Step 4: Check each option.
(A) Incorrect: $k$ and $s$ are not primarily calculated from pseudo-steady-state data.
(B) Incorrect: reservoir geometry is not generally obtained from early transient data unless boundary effects are observed; it is classically obtained from late-time/boundary-dominated behavior.
(C) Correct.
(D) Correct.
Step 5: Conclusion.
The correct options are: \[ \boxed{(C)\ \text{and}\ (D)} \]
In well testing, the transient (infinite-acting radial flow) period is primarily used to estimate:
Permeability ($k$) from the semilog slope, and
Skin ($s$) from the semilog intercept (or equivalent transient relationships).
Hence, $k$ and $s$ are transient-state estimates, not pseudo-steady-state estimates.
Step 2: Identify what is obtained from pseudo-steady-state / boundary-dominated flow.
When the pressure response becomes boundary-dominated (pseudo-steady-state in closed/drainage systems),
the data reflect reservoir size/geometry effects (e.g., drainage area, boundaries).
Thus, reservoir geometry is commonly inferred from pseudo-steady-state / late-time behavior.
So, statement (C) is correct.
Step 3: Evaluate Absolute Open Flow Potential (AOFP) statement.
For a gas well, back pressure (deliverability) tests are used to determine the deliverability equation and estimate
the absolute open flow potential (AOFP) (rate at $p_{wf} \to 0$) by extrapolation.
So, statement (D) is correct.
Step 4: Check each option.
(A) Incorrect: $k$ and $s$ are not primarily calculated from pseudo-steady-state data.
(B) Incorrect: reservoir geometry is not generally obtained from early transient data unless boundary effects are observed; it is classically obtained from late-time/boundary-dominated behavior.
(C) Correct.
(D) Correct.
Step 5: Conclusion.
The correct options are: \[ \boxed{(C)\ \text{and}\ (D)} \]
Was this answer helpful?
0
0
Top Questions on Reservoir capacity
Questions Asked in GATE PE exam
- A vertical well is drilled up to a depth of 4000 ft. Further drilling starts with 10 ppg of fresh mud and 50000 lbf weight on bit (WOB). An equivalent circulation density (ECD) of 10.75 ppg was recorded. The total circulation pressure loss is estimated to be 110 psi. The steel density is 65.5 ppg. The decrease in hook load is _________ lbf (rounded off to one decimal place). (Note: 1 ppg mud is equivalent to 0.052 psi/ft.)
- GATE PE - 2026
- Petroleum Exploration and Drilling Engineering
- The laboratory analysis data obtained from the core is as follows:
Weight of clean dry core in air = 30 g
Weight of core completely saturated with oil = 32 g
Weight of saturated core completely immersed in oil = 24 g
If the density of oil used for saturation of core during the experiment is 0.88 g/cc, then the effective porosity of the core is _________% (rounded off to two decimal places).
- GATE PE - 2026
- Buoyancy and Floatation
- The porosity of a formation with matrix density of 2.65 g/cc and fluid density of 1.0 g/cc is 0.15. The formation has shear modulus of 30 GPa and bulk modulus of 36 GPa. The compressional wave velocity in the formation is _________ $\times 10^3$ m/s (rounded off to two decimal places).
- GATE PE - 2026
- Rock Physics
- In a capillary rise experiment with a capillary tube of length $l_1$, water rises to a height $h$ such that $h<l_1$. If the capillary tube is cut to a length $l_2$ such that $l_2<h$, and the experiment is repeated, which of the following statements is/are CORRECT?
- GATE PE - 2026
- Petroleum Exploration and Drilling Engineering
- Classification of kerogen is based on the relative amount of Carbon (C), Hydrogen (H) and Oxygen (O). Which ONE of the following options is CORRECT about Type II kerogen?
- GATE PE - 2026
- Geochemistry
View More Questions