# Dual Laterlog Measurement Principle

37 Questions | Total Attempts: 51

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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.

• 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.

• 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.

• 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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