List of top Petroleum Engineering Questions on Petroleum Exploration and Drilling Engineering

Which of the following is the basic mechanism of hydrocyclones and centrifuges used for solids control in a drilling operation?
Which of the following is the role of stabilizer subs in the rotary drilling process?
A wellbore has true vertical depth (TVD) of 10000 ft. The pore pressure of formation fluid in the permeable stratum at bottom of wellbore is 6500 psig. Which is/are the acceptable average static mud density value(s) (in lbm/gal) to prevent flow of formation fluid into wellbore?
[Given: 1 lbm/gal mud = 0.052 psi/ft]
A drill string in a wellbore is composed of 6000 ft of drill pipe with an internal diameter of 4.67 inches. Drilling fluid is pumped at a rate of 80 cycles per minute, with a pump factor of 0.21 bbl/cycle. The amount of drilling fluid held in the drill collar and drill bit assembly may be assumed negligible. The time required to circulate the drilling fluid from the surface to the drill bit (in minutes, rounded to two decimal places) is ______. [1 bbl = 5.61 ft\(^3\)]
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).

After well completion, a discovery well in an oil reservoir is produced for a short period and then closed for pressure build-up test. The production history before shut-in is given below. The Horner’s pseudo-producing time, $t_{pH}$, is ............... hr (rounded to nearest integer). 

Production rate (STB/day)Duration (days)
5005
5507
4008

 

A build-up test is characterized by production at constant rate over time $t_p$, followed by shut-in period of $\Delta t$. A plot of shut-in bottom hole pressure ($P_{ws}$) with $\log \left(\dfrac{t_p+\Delta t}{\Delta t}\right)$ for pressure build-up test data is shown in the figure. Which of the following statement(s) is/are TRUE?

Match the flow regimes associated with a vertically fractured well in a reservoir. 

Contact angle measurements are often performed on smooth surfaces to gain information about the wettability of a surface. The interfacial tensions between solid-liquid, liquid-air, and air-solid are $\gamma_{SL}$, $\gamma_{LA}$, and $\gamma_{AS}$, respectively. Which of the following expressions describes the contact angle, $\Theta$? 

A first arrival amplitude of the Cement Bond Log (CBL) of a cased hole section is given in the figure. The identified depth intervals P, Q, and R represent

The response of a four-arm caliper (dual caliper) log in a drilled section is shown in the figure. The borehole features associated with the three identified sections P, Q, and R are:

An opaque cylinder (shown below) is suspended in the path of a parallel beam of light, such that its shadow is cast on a screen oriented perpendicular to the direction of the light beam. The cylinder can be reoriented in any direction within the light beam. Under these conditions, which one of the shadows P, Q, R, and S is NOT possible?

Which one of the given figures P, Q, R, and S represents the graph of the following function? \[ f(x) = |x + 2| - |x - 1| \]

A gamma ray log run across a sand–shale sequence recorded maximum and minimum values of $70$ API and $30$ API, respectively. A bed in this sequence has a gamma log value of $50$ API. Assuming a linear relationship between shale index and shale volume, the volume fraction of shale in the bed is ............. (rounded to one decimal place).
The resistivity reading of a flushed zone across a permeable formation (drilled with water-based mud) is 20 $\Omega\!\cdot$m. Laboratory analysis shows that the resistivity of the core plug (100% saturated with a NaCl brine) from the same formation is 6 $\Omega\!\cdot$m. The resistivity of the NaCl brine is 0.6 $\Omega\!\cdot$m. If the resistivity of the mud filtrate is 0.9 $\Omega\!\cdot$m and Archie's saturation exponent is 2, then the estimated residual hydrocarbon saturation (in percentage) in the flushed zone is ............. (rounded to two decimal places).
Which of the following option(s) is/are indication(s) of a well kick?
Which of the following is/are the route(s) by which a toxic substance may enter a human body?
Polymer flooding enhances oil recovery from an oil reservoir by
Which of the following is necessary for the generation of electrokinetic potential across well-bore and permeable rock formation?
Consider an immiscible liquid mixture of n-decane and water containing fully dissociated NaCl. The number of degrees of freedom for this system is
The information contained in DNA is used to synthesize proteins that are necessary for the functioning of life. DNA is composed of four nucleotides: Adenine (A), Thymine (T), Cytosine (C), and Guanine (G). The information contained in DNA can then be thought of as a sequence of these four nucleotides: A, T, C, and G. DNA has coding and non-coding regions. Coding regions—where the sequence of these nucleotides are read in groups of three to produce individual amino acids—constitute only about 2% of human DNA. For example, the triplet of nucleotides CCG codes for the amino acid glycine, while the triplet GGA codes for the amino acid proline. Multiple amino acids are then assembled to form a protein.
Based only on the information provided above, which of the following statements can be logically inferred with certainty?
(i) The majority of human DNA has no role in the synthesis of proteins.
(ii) The function of about 98% of human DNA is not understood.
In a horizontal circular pipe, liquid and gas are flowing concurrently at the same superficial velocity. However, the average velocity of the gas is greater than the average velocity of liquid. If the slip velocity is equal to the superficial velocity of each of the phases, the fractional liquid holdup is ____________ (rounded off to two decimal places).
An oil well (wellbore radius = 0.5 inch) in a heavy oil reservoir (drainage radius = 745 ft, oil viscosity = 500 cP) is being operated at 200 rb/day and 150 psi under the radial steady state flow regime. A huff and puff steam injection is planned to reduce the oil viscosity to 35 cP. The steam soaks into the reservoir up to a distance of 65 ft from the centre of the wellbore. The new production rate at the downhole condition after the steam stimulation is ____________ rb/day (rounded off to two decimal places).