In the 4th order Runge-Kutta method for solving ordinary differential equations with step size h<1, the ratio of the order of local truncation error to the order of global error is
GATE→2023→Engineering Mathematics→Linear Algebra
Q3
NAT[1 Mark]
Let X be a 3×3 matrix with det(X)=5. The determinant of matrix Y obtained by multiplying row 2 by 2 and row 3 by 3 is
GATE→2023→Engineering Mathematics→Calculus
Q4
NAT[1 Mark]
Consider a vector field V=x3i^+2y2xj^+0.5zk^. The divergence of V at the point (1,2,1) is (rounded to one decimal place).
Using Simpson's one-third rule (with step size h=0.25), the area under the curve y=e−x3, from x=0 to x=1 is (rounded to two decimal places).
GATE→2023→Engineering Mathematics→Calculus
Q7
NAT[2 Marks]
The directional derivative of f=x3+4y2+z2 at the point P(2,1,3) in the direction of the vector V=3i^−4k^ is (rounded to one decimal place).
GATE→2023→Engineering Mathematics→Probability and Statistics
Q8
NAT[2 Marks]
A switch-over event in a producing well occasionally results in a reportable oil leak with probability 1 in 500. With 10 switch-over events per day following a Poisson distribution, the number of days in a 365-day year with no reportable oil leaks is (rounded to nearest integer).
Core
47 Questions
GATE→2023→Core→Petroleum Formation Evaluation
Q9
MCQ[1 Mark]
Which of the following instruments can measure contact angle of a liquid drop placed on a surface?
GATE→2023→Core→Petroleum Production Operations
Q10
MCQ[1 Mark]
Which of the following is the primary role of proppants in hydraulic fracturing?
GATE→2023→Core→Health Safety and Environment in Petroleum Industry
Q11
MCQ[1 Mark]
A mixture of a flammable gas and air can ignite ONLY if
GATE→2023→Core→Reservoir Engineering
Q12
MCQ[1 Mark]
Which of the following relations defines the coefficient of isothermal compressibility (Cg) for a gas? (Here, p,T, and v represent pressure, temperature, and volume)
GATE→2023→Core→Reservoir Engineering
Q13
MCQ[1 Mark]
Consider an ideal liquid-vapor mixture at equilibrium having liquid phase mole fraction xi and gas phase mole fraction yi. For an ideal solution (Raoult's law), the equilibrium ratio (ki) is given by
GATE→2023→Core→Enhanced Oil Recovery Techniques
Q14
MCQ[1 Mark]
In-situ combustion method for enhanced oil recovery is commonly used for
GATE→2023→Core→Petroleum Exploration
Q15
MCQ[1 Mark]
Which of the following is a sedimentary rock?
GATE→2023→Core→Petroleum Exploration
Q16
MCQ[1 Mark]
Kerogen classification (Van Krevelen diagram) plots atomic ratios. Which of the following represents the X-axis and Y-axis, respectively?
GATE→2023→Core→Petroleum Formation Evaluation
Q17
MCQ[1 Mark]
The response of a four-arm caliper log in a drilled section is shown. The borehole features associated with the three identified sections P, Q, and R are
GATE→2023→Core→Petroleum Formation Evaluation
Q18
MCQ[1 Mark]
Which of the following is necessary for the generation of electrokinetic (streaming potential) across well-bore and permeable rock formation?
GATE→2023→Core→Petroleum Formation Evaluation
Q19
MCQ[1 Mark]
A first arrival amplitude of the Cement Bond Log (CBL) of a cased hole section is given. The identified depth intervals P, Q, and R represent
GATE→2023→Core→Reservoir Engineering
Q20
MCQ[1 Mark]
Contact angle measurements are performed on smooth surfaces. The interfacial tensions between solid-liquid, liquid-air, and air-solid are γSL, γLA, and γAS, respectively. Which of the following expressions describes Young's equation for the contact angle, Θ?
GATE→2023→Core→Offshore Drilling and Production Practices
Q21
MCQ[1 Mark]
Which of the following offshore rigs has the HIGHEST water depth operating capability?
GATE→2023→Core→Oil and Gas Well Testing
Q22
MCQ[1 Mark]
Consider an immiscible liquid mixture of n-decane and water containing fully dissociated NaCl. Using Gibbs Phase Rule (F=C−P+2), the number of degrees of freedom for this system is
GATE→2023→Core→Reservoir Engineering
Q23
MSQ[1 Mark]
The mean free path of the gas molecule is 10−6 mm, while the pore size of the rock is 10−3 mm. Which of the following statements is TRUE?
GATE→2023→Core→Health Safety and Environment in Petroleum Industry
Q24
MSQ[1 Mark]
Which of the following is/are the route(s) by which a toxic substance may enter a human body?
GATE→2023→Core→Health Safety and Environment in Petroleum Industry
Q25
MSQ[1 Mark]
Select ALL the safety system(s) that is/are required in an offshore platform.
GATE→2023→Core→Enhanced Oil Recovery Techniques
Q26
MSQ[1 Mark]
Polymer flooding enhances oil recovery from an oil reservoir by
GATE→2023→Core→Petroleum Production Operations
Q27
MSQ[1 Mark]
Which is/are the thermodynamic inhibitor(s) for natural gas hydrate?
GATE→2023→Core→Petroleum Exploration
Q28
MSQ[1 Mark]
Which of the following hydrocarbon trap(s) is/are a result of sedimentary facies changes (stratigraphic traps)?
GATE→2023→Core→Oil and Gas Well Drilling Technology
Q29
MSQ[1 Mark]
Which of the following option(s) is/are indication(s) of a well kick?
GATE→2023→Core→Health Safety and Environment in Petroleum Industry
Q30
MCQ[2 Marks]
Consider an industrial accident scenario involving a drain connection failure, vapor cloud formation, ignition, and eventual burnout. Match the three steps of the accident (P: Initiation, Q: Propagation, R: Termination) to the events:
(I) Formation of vapor cloud
(II) Failure of drain connection
(III) Consumption of all combustibles
GATE→2023→Core→Petroleum Production Operations
Q31
MCQ[2 Marks]
A centrifugal pump running at 500 rpm delivers 60 liters/minute with a head of 50 m. At the same efficiency, if the rotational speed is increased to 1000 rpm, the discharge rate and head would respectively be
GATE→2023→Core→Oil and Gas Well Testing
Q32
MCQ[2 Marks]
Match the flow regimes associated with a vertically fractured well in a reservoir:
(P) Formation Linear Flow
(Q) Fracture Linear Flow
(R) Bilinear Flow
(S) Pseudo-Radial Flow\nwith their corresponding schematic flow descriptions.
GATE→2023→Core→Reservoir Engineering
Q33
MCQ[2 Marks]
Match the organic solid phase deposition regions (I, II, III) around the bubble point curve with Wax, Hydrate, and Asphaltene.
GATE→2023→Core→Petroleum Production Operations
Q34
MCQ[2 Marks]
Match the pure gas hydrate phase diagrams (I, II, III, IV) with the corresponding gases: CH4, CO2, H2S, and N2.
GATE→2023→Core→Petroleum Exploration
Q35
MCQ[2 Marks]
Match the seismic data processing terms in Group-I with their objectives/features in Group-II:
**Group-I:**
(P) Stacking
(Q) Multiple
(R) Bow tie
(S) Deconvolution
**Group-II:**
(I) Synform
(II) Noise reduction
(III) Resolution enhancement
(IV) Echo
GATE→2023→Core→Oil and Gas Well Testing
Q36
MSQ[2 Marks]
Which of the following statement(s) is/are TRUE regarding Horner plot regions (ETR, MTR, LTR) in a pressure build-up test?
GATE→2023→Core→Health Safety and Environment in Petroleum Industry
Q37
MSQ[2 Marks]
Select the statement(s) that is/are TRUE regarding combustion, fire, and explosion fundamentals.
GATE→2023→Core→Offshore Drilling and Production Practices
Q38
NAT[2 Marks]
Figure shows an inextensible catenary mooring cable in still water. Submerged weight per unit length w=100 kg/m, anchor radius x=50 m, horizontal tension Th=1600 kg. The catenary length (AB) is m (rounded to two decimal places).
GATE→2023→Core→Offshore Drilling and Production Practices
Q39
NAT[2 Marks]
An empty steel pipeline with massless endcaps has an outer diameter D and thickness t. Steel density ρs=7850 kg/m3, seawater density ρw=1025 kg/m3. The critical D/t ratio at which the pipeline starts floating is (rounded to two decimal places).
GATE→2023→Core→Reservoir Engineering
Q40
NAT[2 Marks]
Consider the flow of oil and water in a 1D porous medium, with kroo=1, krwo=0.2, Swr=0.2, Sor=0.4, μo=5 cP, μw=1 cP. The total relative mobility (λtotal=kro/μo+krw/μw) at Sw=0.4 is cP−1 (rounded to one decimal place).
GATE→2023→Core→Reservoir Engineering
Q41
NAT[2 Marks]
A binary mixture of n-butane (C4H10) and n-pentane (C5H12) is at 180∘F and 95 psia. Vapor pressures are 160 psia and 54 psia, respectively. Assuming ideal solution behavior (Raoult's and Dalton's laws), the mole fraction of n-butane in the gas phase is (rounded to three decimal places).
GATE→2023→Core→Reservoir Engineering
Q42
NAT[2 Marks]
A highly permeable reservoir with initial pressure of 3000 psi is under active water drive. Stabilized pressure is 2500 psi. Oil production rate = 30,000 STB/day, water production = 0, Bo=1.5 bbl/STB, Bg=0.0007 bbl/scf, Bw=1, GOR=850 scf/STB, Rs=700 scf/scf? (Given Rs=700 scf/STB). The water influx rate is bbl/day (rounded to nearest integer).
GATE→2023→Core→Reservoir Engineering
Q43
NAT[2 Marks]
A volumetric undersaturated solution gas drive reservoir has initial water saturation of 15% (unchanged). After production of 10% of initial oil (Np=0.1N), Bo changes from 1.4 to 1.2 bbl/STB. The final gas saturation in percentage is (rounded to one decimal place).
GATE→2023→Core→Oil and Gas Well Testing
Q44
NAT[2 Marks]
After well completion, a discovery well in an oil reservoir is produced and then closed for a pressure build-up test. Production history: 500 STB/day for 5 days, 550 STB/day for 7 days, 400 STB/day for 8 days. Horner's pseudo-producing time tpH is hr (rounded to nearest integer).
GATE→2023→Core→Petroleum Formation Evaluation
Q45
NAT[2 Marks]
A compressional acoustic wave takes 55μs to travel 0.3048 m through a rock formation having bulk modulus K=37.5 GPa and shear modulus G=31 GPa. The bulk density of the rock is kg/m3 (rounded to two decimal places).
GATE→2023→Core→Petroleum Formation Evaluation
Q46
NAT[2 Marks]
A gamma ray log run across a sand-shale sequence recorded maximum (shale) and minimum (clean sand) values of 70 API and 30 API, respectively. A bed has a gamma log value of 50 API. Assuming a linear relationship, the volume fraction of shale (Vsh) in the bed is (rounded to one decimal place).
GATE→2023→Core→Petroleum Formation Evaluation
Q47
NAT[2 Marks]
Flushed zone resistivity Rxo=20Ω⋅m, 100% brine saturated core resistivity R0=6Ω⋅m, brine resistivity Rw=0.6Ω⋅m, mud filtrate resistivity Rmf=0.9Ω⋅m, saturation exponent n=2. The estimated residual hydrocarbon saturation (Shr=1−Sxo) in percentage is (rounded to two decimal places).
GATE→2023→Core→Enhanced Oil Recovery Techniques
Q48
NAT[2 Marks]
Consider a micellar displacement process in a reservoir with porosity ϕ=0.30. Microemulsion slug volume = 4% of pore volume, with 4 vol% surfactant. Rock density ρrock=2.7 g/cm3, surfactant density ρsurf=1.1 g/cm3. Average surfactant adsorption = 0.25 mg/g of rock. The fraction of injected surfactant adsorbed is (rounded to two decimal places).
GATE→2023→Core→Oil and Gas Well Drilling Technology
Q49
NAT[2 Marks]
A kill mud density is required such that bottomhole pressure equals formation pressure. Shut-in pressure (SIDPP) = 6.8×106 Pa at 3500 m depth. Original mud density ρ1=1100 kg/m3. The kill mud density ρ2 is kg/m3 (rounded to two decimal places).
GATE→2023→Core→Oil and Gas Well Drilling Technology
Q50
NAT[2 Marks]
A non-Newtonian drilling fluid obeying Bingham plastic model (τyx=μpγ˙+τyxo) is placed between two flat parallel plates of area 10 cm2 separated by 1 cm. Force to initiate motion (yield stress) = 300 dyne. Force to keep upper plate moving at 10 cm/s = 600 dyne. The Bingham plastic viscosity μp is dyne⋅s/cm2 (rounded to nearest integer).
GATE→2023→Core→Petroleum Production Operations
Q51
NAT[2 Marks]
Crude oil (ρ=850 kg/m3, μ=2×10−3 Pa⋅s) flows at V=0.35 m/s through a horizontal capillary tube (D=2.5×10−3 m, L=0.30 m). With Fanning friction factor f=16/Re, the pressure drop across the capillary tube is Pa (rounded to one decimal place).
GATE→2023→Core→Reservoir Engineering
Q52
NAT[2 Marks]
An oil droplet is to be mobilized by water injection. Rear radius of curvature rA=25×10−6 m, forward radius of curvature rB=5×10−6 m, wetting contact angle = 0∘, interfacial tension σ=0.025 N/m. The magnitude of the minimum capillary pressure drop required to mobilize the droplet is N/m2 (rounded to nearest integer).
GATE→2023→Core→Offshore Drilling and Production Practices
Q53
NAT[2 Marks]
A four-column semi-submersible floater has column diameter D=5 m each (N=4 columns). Total displaced weight = 4000 tonnes=4×106 kg. Added mass = 50% of mass (ma=0.5m), ρw=1025 kg/m3, g=9.81 m/s2. The natural period of oscillation in heave mode is seconds (rounded to one decimal place).
GATE→2023→Core→Petroleum Production Operations
Q54
NAT[2 Marks]
A shell and tube heat exchanger cools crude oil (3650 kg/h, Cp=2.5 kJ/kg⋅K) from 400 K to 360 K. Water (1600 kg/h, Cp=4.187 kJ/kg⋅K) enters at 310 K. Countercurrent flow, U=300 W/m2⋅K. The heat transfer area required is m2 (rounded to one decimal place).
GATE→2023→Core→Offshore Drilling and Production Practices
Q55
NAT[2 Marks]
An underwater riser with outer diameter Do=250 mm and wall thickness t=20 mm (inner diameter Di=210 mm) is subjected to effective tension Teff=1200 kN, internal pressure Pi=25 MPa, and external pressure Po=6 MPa. The true wall tension in the riser is (in ×106 N, rounded to two decimal places).
General Aptitude
10 Questions
GATE→2023→General Aptitude→Verbal Ability
Q56
MCQ[1 Mark]
The village was nestled in a green spot, ______ the ocean and the hills.
GATE→2023→General Aptitude→Verbal Ability
Q57
MCQ[1 Mark]
Disagree : Protest :: Agree : _____
(By word meaning)
GATE→2023→General Aptitude→Quantitative Aptitude
Q58
MCQ[1 Mark]
A 'frabjous' number is defined as a 3 digit number with all digits odd, and no two adjacent digits being the same. For example, 137 is a frabjous number, while 133 is not. How many such frabjous numbers exist?
GATE→2023→General Aptitude→Quantitative Aptitude
Q59
MCQ[1 Mark]
Which one among the following statements must be TRUE about the median of a set of scores (such as candidates appearing for GATE)?
GATE→2023→General Aptitude→Quantitative Aptitude
Q60
MCQ[1 Mark]
In the given diagram, ovals are marked at different heights (h) of a hill. Which one of the following options P, Q, R, and S depicts the top view of the hill?
GATE→2023→General Aptitude→Verbal Ability
Q61
MCQ[2 Marks]
Residency is a housing complex where all well-established residents are academicians, and most of these academicians are authors of best-selling books. Which statement can be logically inferred with certainty?
GATE→2023→General Aptitude→Quantitative Aptitude
Q62
MCQ[2 Marks]
Ankita has to climb 5 stairs starting at the ground by moving either 1 or 2 stairs up at a stage without moving down. Let F(N) denote the number of possible ways to reach the Nth stair (F(1)=1,F(2)=2,F(3)=3). The value of F(5) is
GATE→2023→General Aptitude→Verbal Ability
Q63
MCQ[2 Marks]
Based on the text stating that only about 2% of human DNA consists of coding regions used to produce proteins, which statement can be logically inferred with certainty?
GATE→2023→General Aptitude→Quantitative Aptitude
Q64
MCQ[2 Marks]
Which one of the given figures P, Q, R and S represents the graph of the function f(x)=∣∣x+2∣−∣x−1∣∣?
GATE→2023→General Aptitude→Quantitative Aptitude
Q65
MCQ[2 Marks]
An opaque cylinder is suspended in the path of a parallel beam of light to cast a shadow. Which of the shadow shapes P, Q, R, and S is NOT possible?