List of top Reservoir Engineering Questions asked in GATE Petroleum Engineering

A real gas is produced from a gas reservoir at a constant temperature of 30°C. The compressibility factor (\(Z\)) is observed to change with pressure (\(P\)) at a rate of \[ \left( \frac{\partial Z}{\partial P} \right)_T = Z^2 \] The difference in the compressibility of the real gas from the ideal gas at a given pressure (\(P\)) and temperature (\(T\)) is:

Capillary pressure (\(P_c\)) vs water saturation (\(S_w\)) curves for different sandstone reservoirs (I, II, III and IV) are given in the following figure.

Which reservoir has the most uniform pore size distribution?

Flow tests are conducted for oil well in reservoirs P, Q, R and S having different parameters as given in the following table. In all the four cases the wells are tested at 1200 stb/day.

Identify the reservoir in which the pressure transient reaches earliest at a point 2000 ft away from the wellbore.

Identify the CORRECT match for the flow regimes (Group 1) with the corresponding slopes of the pressure derivative (Group 2) used in the type curve analysis.

The log data obtained for a particular well section are shown in the following figures. Identify the CORRECT interpretations for different zones.

A homogeneous sandstone reservoir is under a radial steady state flow. The wellbore radius is 0.1 m. The formation near the wellbore is damaged up to 0.9 m from the sand face. The permeability impairment results in \( k/k_s = 5 \), where \( k \) is the permeability in the undamaged region and \( k_s \) is that of the damaged region. The value of skin factor is (rounded off to two decimal places) ______________.

A reservoir is producing oil at 7000 stb/day with a producing gas to oil ratio (GOR) of 2000 scf/stb. At a certain point of time, the reservoir pressure is monitored and decided to be maintained at a constant pressure of 2500 psi using water injection. The PVT properties estimated at 2500 psi are:

Bubble point pressure = 3000 psi
Oil formation volume factor = 1.2 rb/stb
Water formation volume factor = 1.0 rb/stb
Gas formation volume factor = 0.0012 rb/scf
Solution GOR = 300 scf/stb
The initial water injection rate (stb/day) required to maintain oil production at 7000 stb/day is ________________ (rounded off to the nearest integer).

The logging tool(s) preferred for the measurement of formation resistivity in a well drilled with oil-based mud is/are:

The liquid shrinkage curves for different types of crude oil are shown in the following figure.

Which curve represents the Black Oil?

The formation volume factors of oil and water are \(B_o\) and \(B_w\), respectively. The CORRECT relationship between the fractional water cut at the surface condition \(f_{ws}\) and the fractional water cut at the reservoir condition \(f_w\) is: