High Resolution Induction Theory

23 Questions | By Jtodlozil | Updated: Mar 17, 2022 | Attempts: 97

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1.

The primary objective of logging the High Resolution Induction Tool (HRID) is to determine:
- A.
  
  Flushed Zone Resistivity (Rxo)
- B.
  
  Formation Water Resistivity (Rw)
- C.
  
  True Resistivity of the Uninvaded Formation (Rt)
- D.
  
  Mud Filtrate Resistivity (Rmf)
2.

Faraday's Law predicts:
- A.
  
  Resistivity of a formation is inversely proportional to voltage, and directly proportional to current.
- B.
  
  A magnetic field intersecting a coil of wire will induce an alternating voltage in that coil.
- C.
  
  Current in a coil of wire creates an electromotive force.
3.

The magnitude of the primary ground loop current flow is _________ to formation resistivity.
- A.
  
  Proportional
- B.
  
  Inversely Proportional
4.

Ampere's Law predicts:
- A.
  
  Resistivity of a formation is inversely proportional to voltage, and directly proportional to current.
- B.
  
  A magnetic field intersecting a coil of wire will induce an alternating voltage in that coil.
- C.
  
  Current in a coil of wire creates an electromotive force.
5.

Which of the following three voltages induced in a receiver coil is undesirable and is not related to formation resistivity?
- A.
  
  R-Signal
- B.
  
  X-Signal
- C.
  
  Mutual Signal
6.

Which of the following is the primary method of minimizing the mutual signal from the measured receiver voltage?
- A.
  
  Subtraction of sonde error from the measurement
- B.
  
  The use of multiple transmitter and/or receiver coils.
- C.
  
  Measurement of the X-signal in very low resistivity formations
- D.
  
  Correction for skin effect in very low resistivity formations
7.

The resistivity of very low resistivity formations is ____________ if skin effect is not corrected for.
- A.
  
  Underestimated
- B.
  
  Overestimated
8.

The X-signal becomes significant and skin effect becomes a problem in:
- A.
  
  Low resistivity formations
- B.
  
  High resistivity formations
9.

Select all of the following potential applications of the HRID measurements.
- A.
  
  Determination of water saturation
- B.
  
  Estimation of diameter of invasion
- C.
  
  Measure of formation porosity
- D.
  
  Qualitative estimation of permeability
- E.
  
  Measure resistivity of drilling fluid
10.

Select all of the following measured depths of investigation of the HRID
- A.
  
  24 inches
- B.
  
  30 inches
- C.
  
  39 inches
- D.
  
  60 inches
- E.
  
  91 inches
11.

Select all of the following synthetic depths of investigation of the HRID
- A.
  
  24 inches
- B.
  
  30 inches
- C.
  
  39 inches
- D.
  
  60 inches
- E.
  
  91 inches
12.

Select all of the following that must be corrected in order to ensure the 91-inch HRID measurement accurately reflects Rt.
- A.
  
  Invaded mud filtrate
- B.
  
  Permeability
- C.
  
  Formation water resistivity
- D.
  
  Borehole resistivity
- E.
  
  Shoulder bed resistivity
13.

Which of the following conditions can the HRID provide accurate results
- A.
  
  Air drilled holes
- B.
  
  Oil based mud
- C.
  
  Fresh water based mud
- D.
  
  Saltwater based mud
14.

In very low resistivity formations, the magnitude of the primary ground loop current can become quite ______.
- A.
  
  Large
- B.
  
  Small
15.

For a simple two-coil induction tool, the largest receiver voltage component is the mutual signal.
- A.
  
  True
- B.
  
  False
16.

Unfortunately, even with a mutually balanced multi-coil tool, there still remains some small amount of residual coupling between the transmitter coil and the receiver coil. The small and constant voltage signal created by this residual coupling is known as ________.
- A.
  
  Sonde error
- B.
  
  Mutual signal
- C.
  
  Skin effect
17.

The voltage induced by the primary ground loop’s magnetic field is the main signal of interest, and is known as the ______.
- A.
  
  R-Signal
- B.
  
  X-Signal
- C.
  
  Mutual Signal
- D.
  
  Taylor Signal
18.

The R-Signal is ______ proportional to formation resistivity because it is directly related to the magnitude of the ground loop current induced in the formation. But when there is secondary ground loops present in very low resistivity formations, the R-Signal is no longer _____ proportional to formation resistivity which is known as skin effect.
- A.
  
  Inversely
- B.
  
  Directly
- C.
  
  Linearly
- D.
  
  Perpendicularly
19.

The R-Signal has a ______ phase relationship with the transmitter current, and is said to be in-phase with the transmitter current.
- A.
  
  180-degree
- B.
  
  270-degree
- C.
  
  90-degree
- D.
  
  120-degree
20.

The magnetic field associated with the secondary ground loops induces the _______ in the receiver coil.
- A.
  
  X-Signal
- B.
  
  R-Signal
- C.
  
  Mutual Signal
- D.
  
  Taylor Signal
21.

The HRID is unique among induction tools in that it dynamically corrects for skin effect through its measurement of the ______.
- A.
  
  X-Signal
- B.
  
  R-Signal
- C.
  
  Mutual Signal
- D.
  
  Taylor Signal
22.

What are the HRID measured depths of investigation with the DFL?
- A.
  
  17-inches
- B.
  
  24-inches
- C.
  
  30-inches
- D.
  
  39-inches
- E.
  
  60-inches
- F.
  
  91-inches
23.

What are the HRID synthetic depths of investigation with the DFL?
- A.
  
  17-inches
- B.
  
  24-inches
- C.
  
  30-inches
- D.
  
  39-inches
- E.
  
  60-inches
- F.
  
  91-inches