Dual Laterlog Measurement Principle

37 Questions | Total Attempts: 51

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Dual Laterlog Measurement Principle

The Dual Laterlog measurement principle allows the measurement of resistivity using laterlog electrode configuration. It is a rather technical subject, but if it is relevant to you, then there is no other option than taking the quiz. All the best.


Questions and Answers
  • 1. 
    Select the applications of the Dual Laterlog Tool when combined with the Micro-Spherically Focused Log Tool.
    • A. 

      Determination of formation lithology

    • B. 

      Depth of fluid invasion

    • C. 

      Determination of formation density

    • D. 

      Qualitative estimation of formation permeability

    • E. 

      Presence of moveable hydrocarbons

  • 2. 
    The DLLT is primarily used to determine a value of true resistivity for the _______ zone.
    • A. 

      Flushed

    • B. 

      Uninvaded

    • C. 

      Target

    • D. 

      Transition

  • 3. 
    Under which of the following conditions does the DLLT yield the best results?
    • A. 

      Cased Hole

    • B. 

      Oil-based mud

    • C. 

      Freshwater based drilling fluids

    • D. 

      Saltwater based drilling fluids

  • 4. 
    The current flow geometry must be known and constant for the DLLT to provide accurate formation resistivity values.
    • A. 

      True

    • B. 

      False

  • 5. 
    How is the survey current forced beyond the borehole and deeper into the formation?
    • A. 

      Using guard electrodes to emit a focus current

    • B. 

      Using monitor electrodes to emit a focus current

    • C. 

      Increasing the amount of survey current injected into the borehole

    • D. 

      Option 4

  • 6. 
    Select all the characteristics of monitor electrodes on the DLLT.
    • A. 

      Senses imbalances between survey and focus currents

    • B. 

      Ensure zero-potential difference exists between survey and focus currents

    • C. 

      Provides feedback to the tool to increase or decrease focus current as needed

    • D. 

      Forces the survey current to follow the path of least resistance

  • 7. 
    Which of the following does NOT define vertical resolution or depth of investigation of the DLLT?
    • A. 

      Number of monitor electrodes

    • B. 

      Length of guard electrodes

    • C. 

      Survey current frequency

    • D. 

      Distance from A0 electrode to current-return electrode

  • 8. 
    What is the black arrow pointing to in the following diagram?
    • A. 

      Monitor electrode

    • B. 

      A0 electrode

    • C. 

      Guard Electrode

    • D. 

      Survey Current

  • 9. 
    Which of the following statements is true?
    • A. 

      The greater the distance between the A0 and current return electrodes, the deeper the depth of investigation.

    • B. 

      The smaller the distance between the A0 and current return electrodes, the deeper the depth of investigation.

    • C. 

      The greater the distance between the A0 and current return electrodes, the shallower the depth of investigation.

    • D. 

      Taylor is ripped

  • 10. 
    Increasing the spacing between the A0 and current return electrode ________ the measurements vertical resolution.
    • A. 

      Degrades

    • B. 

      Improves

    • C. 

      Does not change

  • 11. 
    Based on the guard lengths, which tool has the greatest depth of investigation?
    • A. 

      Tool A

    • B. 

      Tool B

    • C. 

      Guard length does not affect depth of investigation

    • D. 

      Taylor is a tool

  • 12. 
    Longer guard electrodes result in shallow depths of investigation.
    • A. 

      True

    • B. 

      False

  • 13. 
    Depth of investigation is ________ _________ to the survey current frequency.
    • A. 

      Directly proportional

    • B. 

      Inversely proportional

    • C. 

      Not related

  • 14. 
    What is the vertical resolution of the Shallow Resistivity (LLS) measurement?
    • A. 

      1 Foot

    • B. 

      2 Feet

    • C. 

      3 Feet

    • D. 

      4 Feet

    • E. 

      5 Feet

  • 15. 
    What is the depth of investigation for the Deep Resistivity (LLD) measurement?
    • A. 

      1-3 Feet

    • B. 

      2-4 Feet

    • C. 

      5-7 Feet

    • D. 

      7-9 Feet

  • 16. 
    Including the current return electrode, how many electrodes are present on the DLLT?
    • A. 

      11

    • B. 

      12

    • C. 

      13

    • D. 

      14

    • E. 

      15

  • 17. 
    The shallow LLS and deep LLD measurements use a common A0 electrode to emit two survey currents at different frequencies into the formation.
    • A. 

      True

    • B. 

      False

  • 18. 
    Which electrodes do the shallow measurement LLS use as guard electrodes?
    • A. 

      Upper and lower A3

    • B. 

      Upper and lower A4

    • C. 

      Upper A3 and Lower A4

    • D. 

      Upper A4 and Lower A3

  • 19. 
    Which electrodes does the deep measurement (LLD) use to maintain a zero potential difference between the survey?
    • A. 

      M1 +/- and M2 +/-

    • B. 

      M3 +/- and M2 +/-

    • C. 

      M1 +/- and M3 +/-

  • 20. 
    What electrode provides an Earth ground reference?
    • A. 

      Current Return

    • B. 

      Monitor

    • C. 

      Fish

    • D. 

      Guard

  • 21. 
    What is represented by K in the Ohm's Law equation?
    • A. 

      Resistivity

    • B. 

      Survey Voltage

    • C. 

      Survey Current

    • D. 

      Tool Constant

  • 22. 
    Which of the following electrode(s) serve as the current return for the deep (LLD) measurement?
    • A. 

      Remote current return

    • B. 

      Upper and lower A4

    • C. 

      Upper and lower A3

    • D. 

      Fish

  • 23. 
    Between which of the following electrodes is survey voltage measured for the deep (LLD) and shallow (LLS) measurements?
    • A. 

      M2- and fish

    • B. 

      A0 and current return

    • C. 

      M1 and M2

    • D. 

      M1 and M3

  • 24. 
    Designed to provide measurements of formation resistivity at two distances from the borehole.
    • A. 

      True

    • B. 

      False

  • 25. 
    Log results are presented in units of resistivity (ohm-m), which is the reciprocal of conductivity.
    • A. 

      True

    • B. 

      False

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