Petrophysical Techniques

Disclaimer: While every reasonable effort is made to ensure that the information provided is accurate, no guarantees for the currency or accuracy of information are made. It takes several proof readings and rewrites to bring the quiz to an exceptional level. If you find an error, please contact me as soon as possible. Please indicate the question ID-Number or description because server may randomize the questions and answers.

Questions on Petrophysical Log Interpretation will not appear in the following exam. Log questions are published under a separate section.

Go to: Midterm I | Well Log Interpretation

Geology (GLGY 449-UCAL) Midterm II

Some questions have hints and explanations. Click Start to begin.

Start

Congratulations - you have completed Geology (GLGY 449-UCAL) Midterm II.

You scored %%SCORE%% out of %%TOTAL%%. With incorrect multiple attempts your score is %%PERCENTAGE%%

Your performance has been rated as %%RATING%%

Your answers are highlighted below.

Question 1

Typically Quartz-rich zones will produce about ____ neutron porosity response on a well log. (ID-P02-16)

A	10
B	-2
C	44
D	12
E	19

Question 2

Which of the following porosity modifiers will have the greatest effect on porosity calculated? (ID-P02-10)

A	Quartz cement.
B	Pore filling plagioclase feldspar.
C	Clay mineral cement.
D	Cal mineral lamination.

Question 3

Which of the following is a basic assumption underlying Archie’s equations as applied to sands or sandstone hydrocarbon reservoirs? (ID-P02-04)

A	Clay minerals are only present as discrete laminae.
B	Clay-bearing shale laminae act as insulators between sand layers.
C	Salinity of formation water is the same above and below the oil-water contact.
D	Pressure gradient in the reservoir is the same above and below the oil-water contact.
E	Porosity in the reservoir is the same above and below the oil-water contact.

Question 4

On the following profile of tool-measured resistivities away from the borehole with saline formation water relative to the drilling mud, where is the invaded zone? (ID-P02-22)

A	Section 3
B	Section 4
C	Section 2
D	Section 1
E	Within the borehole

Question 5

In petrophysics, why would two Scientists looking at the same log may have two completely different conclusions? (ID-P02-12)

A	Because logging data have to be correlated with data from several other sources including physical core samples to obtain a near certain or certain conclusions.
B	Because logging data have to be correlated to with core samples to to obtain a near certain or certain conclusions.
C	Because logging tools are often incarcerate hence interpretation is needed to correct tool errors using core driven data sources.
D	Because petrophysics is heavily depend on unknown data sets.
E	Because petrophysics is not a cience.

Question 6

Which of the following is the main assumption underlying Archie’s equation? (ID-P02-06)

A	Oil and gas act as insulators within the formation.
B	Porosity type is same above and below the oil-water contact.
C	Formation is clean and clay free both above and below the oil-water contact.
D	Porosity in the reservoir is the same above and below the oil-water contact.
E	Salinity of formation water is the same above and below the oil-water contact.

Question 7

On the following profile of tool-measured resistivities away from the borehole with saline formation water relative to the drilling mud, what is labeled from 1 to 4? Answer is in respective order. (ID-P02-21)

A	Rxo, Rs, Rm, Rmc
B	Rmc, Ri, Ro, Rt
C	Rm, Rmc, Ri, Rw
D	Rxo, Rmc, Rm, Ri
E	Rmc, Rxo, Ri, Rt

Question 8

What would happen if you treat a hydrocarbon-bearing shale sand as clean? (ID-P02-08)

A	Oil saturation and water saturation will be underestimated.
B	Vertical resistivity will be overestimated.
C	Oil saturation will be underestimated.
D	Oil saturation and water saturation will be overestimated.
E	Water saturation will be underestimated.

Question 9

High permeability reservoir rocks will have which of the following properties? (ID-P02-05)

A	High value of porosity exponent.
B	High value of oil saturation.
C	Low value of bulk density.
D	Low value of Formation Factor.

Question 10

Which of the following property best reflects a high-permeability reservoir rock for a given formation water? (ID-P02-20)

A	High value of oil saturation (So).
B	High value of porosity exponent (m).
C	None of the listed answers are correct.
D	Low value of the formation factor (F).
E	Low value of bulk density.

Question 11

What are approximate vertical resolution and depth of investigation of the ILd, respectively? (ID-P02-02)

A	Vert. Res. = 0.6m and D.I. = 1.6 m
B	Vert. Res. = 2.5 m and D.I. = 1.6 m
C	Vert. Res. = 0.6 m and D.I. = 2.5 m
D	Vert. Res. = 1 m and D.I. = 1.6 m

Question 12

Which of the following is the most important fluid property affecting permeability? (ID-P02-03)

A	Pore geometry
B	Dynamic viscosity
C	Salinity gradient
D	Fluid composition

Question 13

Volumetric flow rate directly proportional to what other variable or condition? (ID-P02-01)

A	Cross sectional area and the height of the fluid column.
B	The rate of flow, q.
C	Height of the fluid column.
D	Cross sectional area.

Question 14

What are approximate vertical resolution and depth of investigation of the ILd, respectively? (ID-P02-09)

A	Vert. Res. = 5 cm and D.I. = 10 cm
B	Vert. Res. = 1 cm and D.I. = 1.6 cm
C	Vert. Res. = 1 cm and D.I. = 5 cm
D	Vert. Res. = 40 m and D.I. = 1.2 m
E	Vert. Res. = 20 cm and D.I. = 30 cm

Question 15

What is the effect of clay mineral conductivity on Ro if the formation water is characterized by moderate to high salinity? (ID-P02-18)

A	Ro will be relatively constant.
B	This will depend on the volume and type of clay minerals.
C	Ro will crease with increasing oil saturation (So).
D	Ro will increase with increasing porosity.

Question 16

Why do standard dipmeter tools require water-based mud? (ID-P02-14)

A	To allow electrons from the formations to flow though to the sensor.
B	To improve responses between electrodes.
C	The hydrogen in water reduces unwanted log responses.
D	To cool down the tool otherwise would be heated due to friction.

Question 17

When using nuclear magnetic resonance (NMR) tools, which of the following would have the greatest influence on relaxation time, T₂, of protons? (ID-P02-11)

A	Average grain size and grain size sorting.
B	Magnitudes of both porosity and permeability.
C	Both amount of porosity and type of lithology.
D	Pore size distribution and pore fluid type.

Question 18

Calculate Sw using the data obtained from following interpreted Pickett Plot. (ID-P02-17)

A	0.09
B	1.08
C	1.00
D	0.08
E	0.65

Question 19

You observe an Gamma Ray response of API between 800 to 850 on a logging output. This type of response is typically associated with what rock type/lithology? (ID-P02-15)

A	Granite or basalt
B	Quartz or calcite-rich
C	Sandstone or sand-rich
D	Coals or coal-rich
E	Shale or shale-rich

Question 20

What are approximate vertical resolution and depth of investigation of the MSFL, respectively? (ID-P02-19)

A	Vert. Res. = 2 m and D.I. = 5 m
B	Vert. Res. = 15 m and D.I. = 5 m
C	Vert. Res. = 40 m and D.I. = 1.5 m
D	Vert. Res. = 2.5 m and D.I. = 1.6 m
E	Vert. Res. = 5 m and D.I. = 10 m

Question 21

When using NMR, the mercury injection method is used for calculating what purpose? (ID-P02-13)

A	To measure permeability and porosity.
B	To measure pore throat radii.
C	To measure water content and saturation in order to identify hydrocarbon bearing zones.
D	For evaluating the effective porosity by separating unconnected porous space.

Question 22

Which of the following region is closest to the borehole? (ID-P02-07)

A	Invaded zone.
B	Mud build up.
C	Flushed zone.
D	Virgin formation.

Question 22 Explanation: 

There is no such thing called, "mud build up". If one of the given choices was "Mud cake", then it would be the correct answer. The next closest one is Flushed zone.

Once you are finished, click the button below. Any items you have not completed will be marked incorrect. Get Results

There are 22 questions to complete.

←

List

→

Return

Shaded items are complete.

1	2	3	4	5
6	7	8	9	10
11	12	13	14	15
16	17	18	19	20
21	22	End

Return

You have completed

questions

question

Your score is

Correct

Wrong

Partial-Credit

You have not finished your quiz. If you leave this page, your progress will be lost.

Correct Answer

You Selected

Not Attempted

Final Score on Quiz

Attempted Questions Correct

Attempted Questions Wrong

Questions Not Attempted

Total Questions on Quiz

Question Details

Results

Date

Score

Hint

Time allowed

minutes

seconds

Time used

Answer Choice(s) Selected

Question Text

All done

Need more practice!

Keep trying!

Not bad!

Good work!

Perfect!

Credits: Based on the excellent class notes provided by, Dr. Rudi Meyer during Fall 2014.
FAQ | Report an Error

If you get a question wrong, you can still click on the other answers. This will open up hints and explanations (if available), which will provide additional information.

Since most well log images and other materials are copyrighted, I cannot use them on my quizzes. Therefore, no well logs can be found in the following quiz. For the exam, you are expected to be able to interpret well logs. If you are a company or an organization willing to donate copies of well logs, please contact me. I really appreciate your contributions.