wayground logo

Free Printable Worksheets

Font size

S
M
L
XL
Worksheets

well logging

Total questions: 129

Worksheet time: 1hrs 5mins

Name
Class
Date
1.

Which modern technique is most commonly used to improve log interpretation in unconventional reservoirs?

a)

Image logs

b)

Image logs

c)

Core analysis

d)

Caliper logs

e)

Machine learning models

2.

Which type of log measure the hydrogen concentration?

a)

Gamma Ray

b)

Resistivity

c)

Density

d)

Neutron

e)

FMI

3.

What is Pef of limestone?

a)

5

b)

3.5

c)

2

d)

4

e)

10

4.

NPHI>DPHI, in Neutron-Density log, indicates what?

a)

shale effect

b)

gas effect

c)

oil effect

d)

high content of hydrocarbon

e)

high content of hydrocarbon

5.

What element contain in high  GR reading zone?

a)

calcite

b)

potassium

c)

gold

d)

radium

e)

plutonium

6.

NPHI<DPHI, in Neutron-Density log, indicates what?

a)

shale effect

b)

gas effect

c)

oil effect

d)

high content of hydrocarbon

e)

high content of shale

7.

What does the resistivity log primarily measure?

a)

Formation porosity



b)

Borehole rugosity

c)

Ability of formation to resist electrical current

d)

Natural radioactivity

e)

Sonic velocity

8.

What does a gamma-ray log typically indicate about the formation?

a)

Water saturation

b)

Porosity

c)

Permeability

d)

Shale content

e)

Borehole collapse

9.

A formation shows low gamma-ray, high resistivity, and moderate
neutron-density porosity. What does this likely indicate?

a)

Shale gas zone

b)

Water-bearing dolomite

c)

Clean sandstone with hydrocarbons

d)

Tight limestone

e)

Salt plug

10.

In an open-hole log, you observe overlapping neutron and density
logs with low gamma-ray values. What does this likely represent?

a)

Shale bed

b)

Water-filled clean sandstone

c)

Gas-bearing tight zone

d)

Salt formation

e)

Oil-filled fractured limestone

11.

A neutron-density log in a well shows a clear crossover with neutron
values lower than density. The gamma-ray log is also low. What is the
most likely lithology and fluid?

a)

Shale with water

b)

Tight carbonate

c)

Gas-bearing sandstone

d)

Shale with gas

e)

Dolomite with oil

12.

What is a primary limitation of traditional well logs in unconventional
reservoirs?

a)

Logs cannot be run in horizontal wells

b)

Poor sensitivity to complex mineralogy and fractures

c)

Data resolution is too high

d)

Tools only work in air-filled boreholes

e)

Logs are too expensive

13.

A sharp increase in resistivity in a clean sand usually indicates:

a)

Water-filled zone

b)

Fractured formation

c)

Presence of hydrocarbons

d)

Salt dome

e)

Shale interbed

14.

Which log is most affected by borehole washouts?

a)

Gamma-ray

b)

Resistivity

c)

Density

d)

Sonic

e)

SP

15.

What lithology typically shows high gamma-ray and low resistivity?

a)

Sandstone

b)

Shale

c)

Salt

d)

Dolomite

e)

Anhydrite

16.

Why is the neutron log sensitive to hydrogen content?

a)

Hydrogen scatters acoustic waves

b)

Hydrogen slows down neutrons

c)

Hydrogen absorbs gamma rays

d)

Hydrogen increases borehole pressure

e)

Hydrogen reflects sonic signals

17.

In cased-hole environments, which log is best for determining
remaining oil saturation?

a)

SP log

b)

Pulsed neutron log

c)

Caliper log

d)

Resistivity log

e)

Gamma-ray

18.

Which of the following logs measures natural electrical potentials in the borehole

a)

GR

b)

Caliper Log

c)

SP

d)

Resistivity Log

e)

Neutron Log

19.

Which type of wave is primarily used in standard sonic logging?

a)

Shear wave

b)

Rayleigh wave

c)

Compressional wave P-wave

d)

Stoneley wave

e)

Surface wave

20.

What would high neutron and high density readings typically indicate?

a)

Fractured zone

b)

Water-filled porous zone

c)

Gas-bearing zone

d)

Salt dome

e)

Hydrocarbon-filled tight limestone

21.

On a sonic log, an increase in interval transit time (Δt) typically suggests:

a)

Lower porosity

b)

Higher porosity

c)

Denser rock

d)

More resistive rock

e)

Gas invasion

22.

In a cased hole, you notice micro-annulus formation behind casing from the CBL. What does it likely indicate?

a)

Tool malfunction

b)

Poor cement bonding

c)

Oil saturation

d)

Caliper error

e)

Shale swelling

23.

In a deviated well, the FMI image shows sinusoidal curves. What does this pattern suggest?

a)

Fault

b)

Dippind beds

c)

Gas crossover

d)

Radioactive mineralization

e)

Casing wear

24.

Which method improves porosity estimation by integrating logs with core data?

a)

Caliper correction

b)

Spectral gamma ray

c)

Petrophysical modeling

d)

SP matching

e)

Resistivity averaging

25.

  Which technique enables visualization of fracture networks in horizontal wells?

a)

Density log

b)

SP log

c)

Cement Bond Log

d)

Mud logging

e)

Borehole image logging

26.

What would a sudden spike in gamma-ray reading most likely represent?

a)

Clean sandstone

b)

Shale-rich bed

c)

Salt dome

d)

Gas-bearing limestone

e)

Carbonate layer

27.

Which log is most affected by hydrogen index of fluids in the pore space?

a)

 Density log

b)

Neutron log

c)

SP log

d)

Caliper

e)

Resistivity

28.

   Which factor decreases the accuracy of porosity estimation from neutron-density logs?

a)

Oil-based mud

b)

Invasion depth

c)

Gas presence

d)

Saltwater saturation

e)

Cased hole logging

29.

  What does a low resistivity and high porosity usually indicate?

a)

Tight formation

b)

Water-filled zone

c)

Gas zone

d)

Shale

e)

Hydrocarbon saturation

30.

   Which tool reading becomes unreliable in highly saline drilling fluids?

a)

Gamma-ray

b)

Resistivity

c)

Neutron

d)

Sonic

e)

Caliper

31.

Which of the following logs cannot typically be run in a cased hole?

a)

Gamma-ray

b)

Resistivity log

c)

CBL

d)

Spectral GR

e)

Caliper

32.

    Which log would best help confirm the quality of the bond between cement and casing?

a)

Gamma-ray

b)

SP log

c)

CBL

d)

FMI

e)

Density log

33.

On a borehole image log, repeating subparallel conductive features dipping at high angles are observed. These are likely:

a)

Bedding planes

b)

Natural fractures

c)

Drilling-induced breakouts

d)

Salt intrusions

e)

Shale laminations

34.

Which of the following logging tools can be used both in open-hole and cased-hole environments?

a)

Density log

b)

Gamma-ray log

c)

Neutron log

d)

Sonic log

e)

SP log

35.

Why is a caliper log important in log interpretation?

a)

Measures porosity directly

b)

Identifies fluid types

c)

Tracks lithology changes

d)

Helps correct for borehole effects

e)

Measures pressure

36.

What effect does borehole enlargement have on density log readings?

a)

Readings become higher than true density

b)

Readings become lower than true density

c)

No impact on the readings

d)

Causes false porosity crossover

e)

Increases gamma-ray count

37.

What is the definition of a well log in the context of formation evaluation?

a)

A report detailing the drilling schedule and rig operations

b)

A core sample extracted from the well for laboratory analysis

c)

A continuous recording of rock and fluid properties along a borehole

d)

A map showing the location of wells in a specific field

e)

A summary of the production history of a reservoir

38.

A sandstone with quartz as the matrix typically shows a matrix density?

a)

2.65 g/cm³

b)

2.56 g/cm³

c)

2.11 g/cm³

d)

2.78 g/cm³

e)

2.14 g/cm³

39.

In a clean sandstone with high resistivity and moderate porosity, the likely fluid is:

a)

Freshwater

b)

Saltwater

c)

Gas

d)

Oil

e)

Mud filtrate

40.

What is the primary limitation of neutron logs in gas-bearing formations?

a)

Overestimation of porosity

b)

Underestimation of density

c)

Poor vertical resolution

d)

Sensitivity to shale volume

e)

Tool sticking in deviated wells

41.

Which of the following methods is best suited for detecting fractures in horizontal wells?

a)

Gamma-ray logging

b)

SP logging

c)

Image logs

d)

Density logging

e)

Neutron porosity logging

42.

Which cased-hole log is used to assess the quality of the cement bond?

a)

Acoustic log

b)

Gamma-ray log

c)

Neutron porosity log

d)

Resistivity log

e)

Caliper log

43.

A cross plot of neutron and density logs shows both values shifting to the right in a shale zone. What does this indicate?

a)

Overpressure reservoir

b)

Organic-rich source rock

c)

High clay content

d)

Gas presence

e)

Cemented sandstone

44.

What causes the typical deflection on an SP log when mud filtrate invades a permeable zone?

a)

Temperature difference between mud and formation

b)

Salinity difference between mud filtrate and formation water

c)

Pressure difference between borehole and formation

d)

Presence of hydrocarbons

e)

Clay content in the formation

45.

What is the main function of the spontaneous potential (SP) log?

a)

Measuring formation resistivity

b)

Determining rock porosity

c)

Estimating borehole diameter

d)

Identifying permeable zones

e)

Measuring natural gamma radiation

46.

Why does a neutron log underestimate porosity in gas-bearing formations?

a)

Neutron tool responds to borehole diameter

b)

Gas has lower hydrogen content than liquids

c)

Gas expands formation matrix

d)

Neutron log ignores shale effects

e)

Gas increases bulk density

47.

What does a neutron log primarily measure in a clean formation?

a)

Bulk density of rock

b)

Natural radioactivity

c)

Hydrogen concentration

d)

Sonic velocity

e)

Matrix porosity

48.

What is the main advantage of Nuclear Magnetic Resonance (NMR) logs over other porosity tools?

a)

Measures formation resistivity

b)

Measures matrix density directly

c)

Is unaffected by lithology changes

d)

Can be used only in cased holes

e)

Detects only hydrocarbons

49.

What is the primary distinction between total porosity and effective porosity?

 

a)

 Total porosity only considers interconnected pores

b)

Effective porosity includes isolated pores

c)

Effective porosity excludes isolated pores and clay-bound water

d)

Total porosity excludes water-filled pores

e)

Effective porosity equals total porosity in all formations

50.

What is the main advantage of mud logging compared to other logging methods?

a)

It provides quantitative reserve estimates

b)

It directly detects oil and gas during drilling  

c)

It measures the porosity of the formation  

d)

It requires no special equipment  

e)

It replaces the need for wireline logging altogether

51.

What is the primary measurement principle of the FMI tool?

a)

Detection of natural gamma radiation

b)

Acoustic wave reflection and velocity

c)

Electrical microresistivity imaging using pad electrodes

d)

Neutron capture by hydrogen atoms

e)

Magnetic resonance of formation fluids

52.

A sandstone formation has a RHOB of 2.35 g/cm³, and the matrix density is 2.65 g/cm³. What does this imply?

a)

The formation contains gas

b)

The formation is very dense

c)

The porosity is unusually low

d)

The formation is likely shale

e)

There is barite invasion

53.

Which condition would most likely reduce SP deflection, potentially leading to incorrect Rw estimation?

a)

Thick clean water-bearing formation

b)

Use of highly conductive mud

c)

Hydrocarbon presence causing SP suppression

d)

High bed porosity

e)

Small borehole diameter

54.

What is the main reason a clean sandstone might still produce a high gamma ray reading?

a)

It contains high porosity

b)

It is highly permeable

c)

It contains potassium feldspars, micas, or glauconite

d)

It has low formation water resistivity

e)

It contains iron oxides

55.

Which of the following factors increases the likelihood of detecting hydrocarbons in mud logging?

 

a)

 High mud overbalance pressure  

b)

Slow drilling rate  

c)

High mud filtration rate

d)

Efficient cuttings removal

e)

Using oil-based mud systems

56.

While drilling through a sandstone reservoir, the gamma ray log shows a consistently low reading, and the SP log exhibits a strong deflection. What is the most likely interpretation of this zone?

a)

Shale with high organic content

b)

Tight carbonate with low porosity

c)

Gas-bearing zone with poor response

d)

Evaporite zone with high resistivity

e)

 Clean sandstone with good permeability

57.

During logging operations in an open hole, the resistivity log shows unusually high values in a zone where the SP log is flat, and the gamma ray indicates a shaly interval. Mud filtrate is fresh water. What is the most reasonable explanation for the high resistivity?

a)

Gas-bearing clean sandstone

b)

Oil zone with low water saturation

c)

Presence of a tight carbonate layer

d)

Freshwater-bearing shale with low salinity formation water

e)

Tool malfunction due to poor borehole condition

58.

Why is the NMR logging tool less influenced by lithology compared to neutron or density logs?

a)

It detects only solid rock matrix

b)

It uses sonic pulses instead of radiation

c)

It directly measures hydrogen in fluids, not in minerals

d)

It measures matrix composition precisely

e)

It responds to radioactive decay

59.

Why is the spectral gamma ray log preferred over the standard gamma ray log in formations with uranium-rich waters or feldspathic sandstones?

a)

It measures porosity independently of lithology

b)

It can be used in air-filled boreholes

c)

It differentiates radioactive elements by energy levels

d)

It gives direct hydrocarbon saturation

e)

It identifies fracture zones through acoustic response

60.

How does FMI logging improve formation evaluation compared to conventional resistivity logs?

a)

It measures porosity directly

b)

It provides high-resolution, oriented images of the borehole wall

c)

It replaces the need for neutron and density logs

d)

It eliminates the need for core samples

e)

It works in cased holes without fluid invasion

61.

In which of the following geological situations would the FMI tool offer the most value over conventional logs?

 

a)

Homogeneous shale intervals with no structural features

b)

Massive carbonate formations with low resistivity contrast

c)

Fractured reservoirs where structural dips and fracture orientation must be evaluated

d)

Salt domes with well-defined acoustic boundaries

e)

Thick clean sandstones identified by gamma ray and resistivity logs

62.

What does the SP log deflection indicate in a well log?

a)

The presence of hydrocarbons

b)

A porous and permeable formation

c)

A non-reservoir shale zone

d)

The depth of casing shoe

e)

The lithology transition from carbonate to shale

63.

What is the primary difference between Wireline Openhole Logging and Wireline Casedhole Logging?

a)

Openhole logging is used only for gas wells, while casedhole logging is for oil wells

b)

Openhole logging evaluates formation properties before casing is installed; casedhole logging is done after casing and completion, mainly for monitoring

c)

Openhole logging only uses gamma ray tools, while casedhole logging only uses acoustic tools

d)

Casedhole logging provides better porosity data than openhole logging

e)

There is no operational or data difference between the two

64.

What does the RHOB log measure?

a)

The amount of hydrocarbons in the reservoir

b)

The electrical resistivity of the formation

c)

The bulk density of the formation using gamma ray absorption

d)

The porosity of the formation using neutron count

e)

The formation's ability to transmit sound waves

65.

How does data acquisition of electronic borehole images occur?

a)

By sending electrical pulses into the formation to detect hydrocarbons

b)

By using wireline tools to capture optical photographs of the borehole wall

c)

By recording formation acoustic emissions during drilling

d)

By scanning the borehole wall with pads or button electrodes that measure microresistivity or acoustic responses

e)

By measuring formation temperature variations at multiple depths

66.

The sonic log measures the interval transit time (∆t) of a compressional sound wave traveling through the formation. What does this measurement primarily indicate?

a)

Formation resistivity

b)

Fluid saturation

c)

Porosity of the rock

d)

Natural gamma radiation

e)

Bulk density

67.

What does SSP (Static Spontaneous Potential) represent in well logging?

a)

The maximum resistivity reading in a shale zone

b)

The maximum deflection of the SP curve in a thick, clean (shale-free), permeable formation

c)

The baseline shift in the SP log due to borehole fluid invasion

d)

The minimum SP response in a non-permeable zone

68.

What does effective porosity measure in a reservoir rock?

a)

Total void space, including isolated pores

b)

Only the interconnected pores that contribute to fluid flow

c)

The percentage of shale content in the rock

d)

The density of the rock matrix

69.

What is the primary purpose of an induction log in well logging?

a)

To measure natural gamma radiation

b)

To determine formation resistivity in non-conductive (oil-based) muds

c)

To calculate porosity using acoustic waves

d)

To detect shale content

70.

What is a key limitation of induction logs?

a)

Poor resolution in thin beds

b)

Requires conductive mud

c)

Cannot measure resistivity

d)

Only works in cased holes

71.

What is a key advantage of NMR logging compared to porosity logs?

a)

Measuring formation resistivity

b)

Differentiating between moveable and irreducible fluids

c)

Detecting natural gamma radiation

d)

Identifying lithology changes

72.

How does an acoustic borehole imaging tool generate data?

a)

By measuring natural gamma radiation from formations

b)

Using a rotating transducer that emits/receives high-frequency sound waves

c)

Through electrodes that inject current into the formation

d)

By detecting neutron interactions with formation fluids

73.

A low CBL amplitude reading typically indicates:

a)

Poor cement bonding (free pipe)

b)

Good cement-to-casing bond

c)

High formation porosity

d)

Casing corrosion

74.

Which factor does NOT affect CBL measurements?

a)

Casing size

b)

Cement compressive strength

c)

Formation resistivity

d)

Tool centralization

75.

Which drilling fluid environment is REQUIRED for standard electric imaging tools to function properly?

a)

Oil-based mud

b)

Air or gas

c)

Water-based conductive mud

d)

Foam drilling fluid

76.

Which factor would NOT affect the SP log response?

a)

Formation water salinity

b)

Mud filtrate salinity

c)

Borehole diameter

d)

Formation porosity

77.

What does a "baseline shift" on an SP log typically indicate?

a)

A change in lithology (e.g., sand to shale)

b)

A variation in formation water salinity

c)

A fault or unconformity

d)

All of the above

78.

Determine the maximum deflection of the SP curve

a)

-50Mv

b)

-45Mv

c)

-40Mv

d)

-55Mv

79.

Define the effective porosity

a)

amount of void space that is interconnected

b)

amount of void space that is isolated

c)

amount of vois space both isolated and interconnected

d)

ratio of the total pore volume to the total volume of rock

e)

ratio of the isolated pore volume to the total bulk volume
learning objective: test our understanding of porosity and its types

80.

What is irreducible water saturation

a)

amount of water that is movable and has a good permeability

b)

ratio of formation water occupying pores to the total pore space in rock

c)

water saturation at which all the water is held in the capillaries by
capillary pressure

d)

water saturation at which all the water can be easily transmitted through
the pores

e)

ratio of formation oil occupying the pores to the total pore space
learning objective: shows our understanding of irreducible, residual,
connate water saturation

81.

What is the common and typical value for density of sandstone in g/cm3

a)

1.0

b)

2.64

c)

2.71

d)

2.87

e)

2.96

82.

If the actual real density of matrix is less than typical value that we use for
calculations, what will be with porosity

a)

It doesn’t change

b)

It will overestimate

c)

It will underestimate

d)

It will show value less than actual porosity

e)

Porosity doesn’t depend on density of matrix
learning objective: test our ability to analyze how parameters will change
if we apply some wrong and not actual values

83.

Why in gas reservoirs neutron log show to us low value

a)

Because gas has high concentration of hydrogen

b)

Because gas has low concentration of hydrogen

c)

Because gas absorbs neutrons faster than liquids

d)

Because gas has a higher density than oil or water

e)

Because neutron tools cannot detect gas at all

84.

What is measured by induction log

a)

Resistivity

b)

Porosity

c)

Lithology

d)

Permeability

e)

Conductivity

85.

What parameter cannot be calculated by NMR

a)

Porosity

b)

Grain size

c)

Pore distribution

d)

Lithology

e)

Viscosity

86.

Choose statement that describe this zone

a)

Impermeable with large pores

b)

Permeable with large pores

c)

Impermeable with very small pores

d)

Permeable with small pores

e)

Permeable with isolated pores
learning objective: test our ability to analyze interpretation based on
gamma ray, NMP logs and finding permeable zones

87.

What does Cement bond log (CBL) measure

a)

Quality of cement slurry

b)

Amplitude of waves propagating axially along with a casing

c)

Thickness of cement between the casing and formation

d)

Density and viscosity of cement

e)

All of them

88.

What does electrical borehole imager record?

a)

Gather image

b)

Microresistivity

c)

Lithology

d)

Porosity

e)

Video image

89.

From which reservoir do the fluids come?

a)

From above reservoir

b)

From below reservoir

c)

From both reservoirs

d)

From higher reservoirs

e)

None of them

90.

Why it is important to use centraliser in acoustic borehole imager?

a)

Because waves should reach the walls of the well at the same
speed and be reflected correctly

b)

Because it increases the speed of logging

c)

Because it is necessary to measure the temperature in the well

d)

Because the waves travel through the rock faster

e)

All of them

91.

Why does density log show lower value when there are fluids than when
there are no fluids?

a)

Because fluids reduce the total volume of the rock, increasing its density

b)

Because fluids have lower density than solids and reduce the bulk
density

c)

Because fluids increase the porosity of the rock, resulting in more water

d)

Because fluids absorb more gamma rays, increasing the density
readings

e)

Because fluids have very high density and increase the RHOB
learning objective: require our analysis of bulk density and densities of
fluids and matrix and how they affect bulk density

92.

In which zone can you see the gas presence?

a)

1

b)

2

c)

3

d)

no gas

e)

only water

93.

The higher the matrix velocity(ft/sec), the _______ the transit time (∆t
µsec/ft) in sonic log

a)

Equal to velocity

b)

Smaller

c)

Greater

d)

Same for all rock types

e)

None of them

94.

What is the reason of the drop in resistivity on this profile (mud filtrate –
fresh water):

a)

Due to presence of flushed mud filtrate

b)

Due to fractures present in the rocks

c)

Due to good permeability

d)

Due to the high concentration of formation water

e)

Due to high effective porosity

95.

How can you describe the following cement job:

a)

Perfect cement job

b)

Good cement job

c)

Bad cement job

d)

Perfect casing-cement bond

e)

Good formation-cement bond

96.

A formation has high gamma ray and high potassium readings, but low thorium and uranium. What does this indicate?

a)

Uranium-rich shale

b)

Shale-free carbonate

c)

Feldspathic or glauconitic sandstone

d)

Coal seam

e)

Salt intrusion

97.

The SP curve shows a deflection to the right of the shale baseline. What does this most likely indicate?

a)

A) Hydrocarbon suppression

b)

Rmf < Rw Reversed SP

c)

Shale-rich zone

d)

Presence of potassium feldspar

e)

Rmf > Rw Normal SP

98.

In which scenario is the SP curve likely to show no deflection from the shale baseline?

a)

Permeable sandstone

b)

Rmf = Rw

c)

Shale with uranium

d)

High porosity carbonate

e)

Hydrocarbon-bearing sandstone

99.

You’re evaluating a thin bed (<10 ft) permeable sandstone with measured SP = –40 mV. Why might this not reflect the true SSP?

a)

Because it's gas-bearing

b)

Because Rmf > Rw
correct

c)

Because bed thickness reduces SP deflection

d)

Because hydrocarbon saturation increases SP

e)

Because the log is too shallow

100.

What is a major advantage of Fullbore MicroImager (FMI) logs over traditional dipmeters?

a)

They can operate without pads

b)

They use acoustic sensors instead of resistivity

c)

They provide faster logging speeds

d)

They offer higher borehole wall coverage and resolution

e)

They eliminate the need for any processing

101.

What is the key reason image logs require slow logging speeds (e.g., 10'–50' per hour)?



a)

To avoid overheating the tool

b)

To ensure high-resolution data acquisition and image quality

c)

To synchronize with gamma-ray logs

d)

To prevent tool sticking

e)

To allow magnetometer calibration

102.

What is a major limitation of running open-hole logs compared to cased-hole logs?

a)

Cannot measure porosity

b)

Requires perforation first

c)

Provides lower resolution than cased-hole tools
correct

d)

Susceptible to birehole environment effcts like washoits and mud invasion

e)

Cannot measure formation resistivity

103.

What does SFLU logging show?

a)

formation resistivity Rt

b)

The resistivity of the flushed zone Rxo

c)

The resistivity of invaded zone Ri

d)

Resistivity of mud filtrate Rmf

e)

Resistivity of formation water Rw

104.

What does the “Hot Wire” sensor measure during drilling?

a)

The rate of speed

b)

The electrical conductivity of the fracture

c)

The presence and concentration of CH gases in the drilling mud

d)

The volume of cuttings

e)

The temperature of drill mud

105.

Difference between Time domain analysis and diffusion analysis in interpretation data of NMR?

a)

Time domain analysis shows T1, and diffusion shows T2 

b)

The measurement of rock resistance in various fluids

c)

The use of short and long current pulses

d)

The comparison of different Tw and echo spacing intervals Te

e)

In showing the content of CH

106.

What is T2 cutoff in NMR logging and what does it do?

a)

Transverse relaxation time, show the small pores

b)

Relaxation time, separating bound and mobile fluid

c)

Longitudinal relaxation time, show the small pores

d)

Relaxation time, unites large and small pores

e)

Relaxation time, show the permeable and porous zones

107.

What is the ratio from Sxo/Sw (flushed/uninvaded zones) used for?

a)

to determine the saturation of formation water

b)

to determine the water saturation

c)

to determine the mobility of a hydrocarbon

d)

to determine the mobility of water in shales

e)

to determine the mobility of free fluid

108.

What does the term BVW (bulk volume water) mean and what is it for?

a)

the volume of water that can be retained in the rock without desplacing oil

b)

the volume of oil that can last without displacing water

c)

the volume of water that can displace a hydrocarbon

d)

the calculated volume of water needed for the drill mud

e)

the volume of water that can displace gas in pore spaces

109.

Which method does not require a porosity value when calculating Sw?

a)

Archie’s equation method 

b)

Density logging method

c)

Resistivity logging method

d)

Wyllie’s equation method

e)

Ratio method

110.

   In SP deflection, what does this region represents?

a)

Rmf=Rw

b)

Rmf>Rw

c)

Rmf<Rw

d)

Rmf=0

e)

Rw=0

111.

   Which drilling fluid could be used with GR log?

a)

Cement slurry

b)

Water-based mud

c)

Air-based fluid

d)

Oil-based mud

e)

Salt-saturated gel

112.

  1. What zones are NMR not used in?

a)

water-saturated zones

b)

hydrogen-bearing zones

c)

high porosity sandstone zones

d)

uninvaded zones

e)

zones with clay content

113.

  1. What does hydrogen effects causes?

a)

Reduction in borehole diameter

b)

It could increase interval transit time

c)

Decrease in gamma ray response in shales

d)

Sudden changes in mud cake thickness

e)

Complete loss of resistivity readings

114.

What does M represents?

a)

M is the plane

b)

M is the cemented fracture

c)

M is the small-scale fault

d)

M is the open fracture

115.

In the Resistivity log there several fluid distribution profiles, which of them characterized by being the most realistic model of true borehole conditions?

a)

Annulus profile

b)

Step profile

c)

Transition profile

d)

Casing profile

e)

Spontaneous profile

116.

In hydrocarbon-bearing zones, the SP deflection is reduced. What is this effect called?

a)

Shale effect

b)

Baseline effect

c)

Water suppression

d)

Hydrocarbon suppression

e)

Klinkenberg effect

117.

Borehole images are electronic pictures of rocks and fluids encountered by a wellbore. What main applications of FMI?


a)

Qualitative profile, Rock texture

b)

Saturation, Permeable zone

c)

Porosity, Density

d)

Hydrocarbon zones, Secondary porosity profile

e)

Borehole rugosity, Cavings

118.

Which logging method provides direct NMR porosity and fluid typing (movable vs. bound water)?

a)

Density log

b)

Neutron log

c)

Resistivity log

d)

Magnetic resonance Imaging log

e)

Sonic log

119.

Which logging tool is least affected by shale content?

a)

SP log

b)

Resistivity log

c)

Neutron log

d)

Gamma ray log

e)

Density log

120.

What effect does borehole washout have on neutron-density readings

a)

Increases both readings

b)

Decreases both readings

c)

Creates incorrect porosity crossover

d)

No effect

e)

Only affects resistivity logs

121.

In a clean sandstone, what typical gamma ray readings are?

a)

45-65

b)

0-25

c)

75-100

d)

50-75

e)

65-85

122.

In open-hole logging, tools are deployed in:

a)

Cemented casing

b)

Tubing

c)

Bare formation without casing

d)

Fracture zones only

e)

Mud cake

123.

Which condition causes high resistivity readings in a water-bearing zone?

a)

Freshwater mud

b)

Hydrocarbon invasion

c)

Saltwater

d)

Shale interference

e)

High porosity

124.

What is the primary use of density-neutron crossplots?



a)

Estimate formation dip

b)

Identify lithology and gas zones

c)

Calculate temperature gradient

d)

Detect mud invasion

e)

Measure borehole size

125.




Resistivity log is used to identify hydrocarbon presence in formation by measuring resistivity of fluids within it. What typical logs we use?



a)

DTLN, IMPH, SFLU

b)

DTSM, DTLF, SFLU

c)

IMPH, NPHU, RHOB

d)

SFLU, IMPH, IDPH

e)

PEF, SFLU, IMPH

126.

GR log measures the natural radioactivity in formations, however it can not differentiate specific types of mineral. What is it?



a)

Shale

b)

Limestone

c)

Clay

d)

Salt

e)

Quartz

127.

Cased-hole logging tools rely primarily on which method?



a)

Nuclear and acoustic measurements

b)

Resistivity only

c)

Sonic and SP

d)

Open-hole gamma tools

e)

MRI imaging

128.

The Archie equation was the first empirical model built (1942) to estimate the water saturation in non conductive matrix rocks. Which combination of logs are best estimate water saturation?

a)

Sonic and caliper logs

b)

Resistivity and porosity logs

c)

SP and gamma ray

d)

Density and caliper

e)

Neutron and gamma ray

129.

. Based on the log snippet provided, which of the following interpretations is most accurate for the zone around 7450–7480 ft?

a)

Shale-rich zone with poor permeability

b)

Clean sandstone, water-bearing

c)

Clean sandstone, hydrocarbon-bearing

d)

Fractured carbonate zone

e)

Tight gas reservoir with low porosity

Similar Resources on Wayground

Elec group quiz

125 questions

Elec group quiz

quiz

Worksheet

•

University

Worksheet MCQs extracted from provided images

125 questions

Worksheet MCQs extracted from provided images

quiz

Worksheet

•

University