List of top Petroleum Engineering Questions

Which of the following definition(s) related to fire and explosion is/are CORRECT?

In a capillary rise experiment with a capillary tube of length $l_1$, water rises to a height $h$ such that $h \lt l_1$.

If the capillary tube is cut to a length $l_2$ such that $l_2 \lt h$, and the experiment is repeated, which of the following statements is/are CORRECT?

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?

Crude oil denser than pure water has the API gravity

Match the well logging methods in GROUP I with their corresponding measured parameters in GROUP II:

Three different pressure profiles are shown in the figure. CSD is Casing Setting Depth.
Match the entries in GROUP I with the entries in GROUP II.

Which ONE of the following rocks shows the highest reading in the natural gamma ray log?

A homogeneous rock layer $ Q $ of density 2600 kg/m³ is lying below homogeneous rock layer P of density 2400 kg/m³. A compressional wave travels from P to Q. On reaching the interface of P and Q, this wave is incident normally and gets reflected and refracted. The velocity of the compressional wave is 2.7 km/s in the rock layer P and 3.5 km/s in layer Q.
The ratio of reflection coefficient to the transmission coefficient at the interface is .......... (rounded off to two decimal places).

A horizontal well is planned with two radial sections to land the target at an angle of 90°. The total vertical depth (TVD) between the surface and the target is 8000 ft. The buildup rate is 6° per 100 ft in the first section and 9° per 100 ft in the second section. The total angle built by the second section is 30°.
The distance of the first kickoff point from the surface is .......... ft (rounded off to one decimal place).

The Buckley Leverett frontal advance theory is employed to evaluate the performance of the water flooding operation in a horizontal reservoir.
The following data are given:
- Cross-sectional flow area = 40000 ft²
- Payzone thickness = 20 ft
- Porosity = 20%
- Water injection rate = 1000 rb/day
- Distance between injection and production well = 1000 ft
- Cumulative pore volume of water injected (PVWI) at breakthrough = 0.5
The time of breakthrough is .......... days (rounded off to one decimal place).

A hydraulically fractured vertical well has fracture permeability of 4000 mD, fracture width of 0.12 in, and fracture half-length of 1000 ft.
Dimensionless fracture conductivity is .......... $ \times 10^{-4} $ (rounded off to two decimal places).

Correlation equations for gas compressibility factor ($ z $) and viscosity ($ \mu $) as functions of pressure ($ p $) are as given below.
\[ z = C_1 p^{-0.25}, \quad \mu = C_2 p^{1.25} \] where $ C_1 $ and $ C_2 $ are constants, consistent with the field units (pressure in psi and viscosity $ \mu $ in cP), and have values 1.96 and $ 7 \times 10^{-4} $, respectively.
Real gas pseudo pressure corresponding to a pressure of 2500 psi is .......... $ \times 10^6 $ psi²/cP (rounded off to two decimal places).

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?

The formation resistivity factor ($ F $) is related to the formation porosity ($ \phi $) in a water-bearing carbonate formation by the following correlation:
\[ F = 0.9 \phi^{-2} \] where $ \phi $ is in fraction. The resistivity of the invaded zone of the formation obtained by the Microspherically Focused Log (MSFL) is 4.5 $ \Omega $m, and the resistivity of the mud-filtrate is 0.05 $ \Omega $m. The formation porosity is .......... % (rounded off to one decimal place).

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).

Which of the following logging tool(s) underestimate(s) porosity in a gas-bearing formation?

Which of the following definition(s) related to fire and explosion is/are CORRECT?

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?

The maximum Polished Rod Load (PRL) in the operation of the sucker rod pump is observed near the

A shell-and-tube heat exchanger is used for cooling crude oil from $400~\text{K}$ to $360~\text{K}$. Crude oil flows through the tube at $3650~\text{kg/h}$. Water enters the shell side at $310~\text{K}$ and has a flow rate of $1600~\text{kg/h}$. Assume $c_{p,\text{oil}}=2.5~\text{kJ/(kg.K)}$, $c_{p,\text{w}}=4.187~\text{kJ/(kg.K)}$, overall $U=300~\text{W/(m}^2\!\cdot\!\text{K)}$, and countercurrent flow. The required heat–transfer area is ............... m$^2$ (rounded to one decimal place).

An oil droplet is to be mobilized by injecting water through a pore throat. The oil–water interface has the rear radius of curvature $r_A = 25\times10^{-6}\ \text{m}$ and the forward radius of curvature $r_B = 5\times10^{-6}\ \text{m}$. The pore is completely water-wet (contact angle $=0^\circ$) and interfacial tension is $\sigma = 0.025\ \text{N/m}$. The minimum pressure drop required to mobilize the trapped oil droplet is ________ N/m$^2$ (nearest integer).

Crude oil having density and viscosity of $850\ \text{kg/m}^3$ and $2\times10^{-3}\ \text{Pa}\!\cdot\!\text{s}$, respectively, is flowing at an average velocity of $0.35\ \text{m/s}$ through a horizontal capillary tube. The inside diameter and length of the capillary tube are $2.5\times10^{-3}\ \text{m}$ and $0.30\ \text{m}$, respectively. The Fanning friction factor is $f=\dfrac{16}{\mathrm{Re}}$. The pressure drop across the capillary tube is ________ Pa (rounded to one decimal place).

A non-Newtonian drilling fluid (Bingham plastic) is between two flat parallel rectangular plates of area $10\ \mathrm{cm^2}$ each, separated by $1\ \mathrm{cm}$. A force of $300$ dyne is required to initiate motion of the upper plate. A force of $600$ dyne keeps the plate moving at a constant velocity of $10\ \mathrm{cm/s}$. The constitutive law is \[ \tau_{yx} = \mu_p \dot{\gamma} + \tau^o_{yx}. \] Find the Bingham plastic viscosity $\mu_p$ in dyne$\cdot$s/cm$^2$ (rounded to the nearest integer).

A kill mud of appropriate density is required to be injected in a well such that the shut-in pressure is $6.8 \times 10^{6}\ \mathrm{Pa}$ at a depth of $3500\ \mathrm{m}$. Here, the shut-in pressure is the quantity by which the bottom-hole pressure exceeds the hydrostatic pressure of the original mud at the given depth. The density of the original mud is $1100\ \mathrm{kg/m^3}$. The density of the kill mud is _________ kg/m$^3$ (rounded to two decimal places).

Consider a micellar displacement process in a homogeneous reservoir with a porosity of 30%. The volume of the microemulsion slug to be injected is 4% of the pore volume. The slug contains 4 vol% surfactant. The density of the rock and the surfactant is $2.7~\text{g/cm}^3$ and $1.1~\text{g/cm}^3$, respectively.

Assuming that the average surfactant adsorption is 0.25 mg/g of the reservoir rock, the fraction of the injected surfactant that will be adsorbed is ............. (rounded to two decimal places).