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WorksheetsNuclear/Radioactive Properties of Rocks
Total questions: 25
Worksheet time: 50mins
An atom nuclide has a unique set of discrete energy levels or states. At which states of nucleus is the most unstable?
At higher energy level
At lower energy level
At middle energy level
Right in the core
What is gamma radiation
positron radiation
electron radiation
electromagnetic/ photon radiation
Which are not the origin of natural gamma radiation in rocks?
U-Ra
Th
K
He
What isotop is impossible to use to absolute dating the 5 Mya -old rocks?
U
Th
K
C
What is the sister of a potassium parent?
Uranium
Thorium
Lead
Argon
These are the sources of potassium in rocks, except?
Clay minerals
Carbonate
K-feldspar
What is the source of radioactive emission in carbonate reservoirs?
Uranium
Thorium
Potassium
Where does uranium majorly occure?
Phosphates, organic matter
Shales, heavy minerals
Feldspars, Illite
What you see is general tendencies of natural radioactivity of rocks. Which the following statement is wrong?
Basalts are more radioactive than Granites
Shaly carbonates are more radioactive than coal
Gamma measurements are done either by spectral measurement (count per second) or integral measurement (API unit).
True
False
I do not know
Absolute rocks and fossils dating is based on decay process of unstable elements.
Agree
Disagree
What radioactive element contributes more to GR (API) in the shaded interval ?
Uranium
Potassium
Thorium
Among the applications of radioactive properties in rocks are, unless..
Lithological discremination
Shale content elimination
Clay mineral typing
Source rock studies
The lithospheric heat flow is greater (65 mW/m2) than the heat flow from the mantle in continental areas (20 mW/m2). Why is that?
Radioactive elements (K, U, and Th) occuring in the Earth's crust produce significant heat.
Radioactive elements (K, U, and Th) occuring in the Earth's mantle do not produce heat.
Beside the natural gamma ray, rocks also interact with an artificial gamma radiation. This interaction is detected by a gamma detector. Two effects are applied as the result of the interaction, unless...
Compton effect
Photoelectric effect
Side effect
If gamma photon is emitted from a gamma source and it interacts with the rocks, types of interaction that probably occurred depends on..
the energy of the emitted gamma radiation
the frequency of the emitted gamma radiation
the atomic number of the target element
all the above option is true
Photoelectric index (PE) is used to measure ...
rock's mineralogy
mud content in rocks
grain's shape
Compton energy interaction can be used to measure...
bulk density
porosity
both
Neutron radiation can be used to measure "neutron porosity" i.e. the elastic scattering interaction of neutron indicating hydrogen concentration. What does the neutron porosity mean?
Exact true porosity in a water-bearing limestone formation
Not exact true porosity until fluid/formation/shale correction is done in non-water-bearing limestone formation
Porosity based on hydrogen concentration under certain lithological calibration
All the answers are true
Nuclear spectroscopy methods is used to deliver %w of certain elements, but they cannot deliver a full mineral analysis until these some measurements are accomplished i.e. elemental concentration measurement, general lithology categorisation, and specific lithology categorisation. The given spectroscopy of chemical composition is used in what measure?
Elemental concentration
General lithology categorisation
Specific lithology categorisation
all the answers are true
What is the carbonate bulk density and its neutron porosity if it consists of 50%v Calcite, 20%v Dolomite, and 30%v porosity saturated with oil?
2.169 and 0.302, respectively
2.619 and 0.341, respectively
2.169 and 0.270, respectively
2.619 and 0.270, respectively
The profile consists of carbonate rocks with mixed lithology. The derivation of volumetric rock composition including matrix and porosity composition is derived from RHOB and NPHI readings. What is the mixture of calcite, dolomite and its porosity filled with water at the depth of 9230 ft?
75%v Calcite, 13%v Dolomite, 12%v pore-filled water
13%v Calcite, 12%v Dolomite, 75%v pore-filled water
13%v Calcite, 75%v Dolomite, 12%v pore-filled water
12%v Calcite, 13%v Dolomite, 75%v pore-filled water
What is volume of shale (Vsh) at the depth of 1000 m using linear response?
25%
50%
70%
90%
What is the age of the fossil sample in a rock if 70% of Carbon-14 has been decayed into its Nitrogen sister?
2910 +/- 20 years old
5450 +/- 40 years old
9900 +/- 70 years old
13200 +/- 90 years old
A monoenergetic gamma radiation emitted by a K-Ar decays is 1.46 MeV. What is the spectra of that gamma radiation?
5.33 x 1020 Hz
3.53 x 1010 Hz
3.53 x 1020 Hz
5.33 x 1010 Hz
