# Shared Flashcard Set

## Details

Sonic Log
Lecture 9
10
Engineering
Not Applicable
05/30/2016

Term
 What does the sonic log measure?A) Measure travel time of an elastic wave through the formation. B) Measure natural waves in the formation C) Measure frequency of collison of the waves D) Measure the amplitude of a wave through the formation
Definition
 A) Measure travel time of an elastic wave through the formation.
Term
 What is the main use of a sonic log?   A) To find permeability B) To find the density of the formation C) To find Elvis D) To provide information to support and calibrate seismic data and to derive the porosity of a formation
Definition
 D) To provide information to support and calibrate seismic data and to derive the porosity of a formation
Term
 Does the sonic tool work at a higher or lower frequency than seismic waves?
Definition
 The sonic tool works at a higher frequency than seismic waves.
Term
 What is the first type of wave that will arrive the receiver?
Definition
 The first wave to arrive is the compressional (P-wave).
Term
 What type of wave will arrive after the P-wave?
Definition
 The next wave, usually, to arrive is the transverse or shear wave.
Term
 Can shear wave propagate in fluids?
Definition
 The shear wave cannot propagate in fluids, as fluids do not behave elastically under shear deformation.
Term
 Write Wyllie's equation:
Definition
 [image]
Term
 How can we find the velocity of the wave?
Definition
 Measure the distance from transmitter to receiver. dt=1/Vp
Term
 How is sonic log data presented?
Definition
 The data is presented as a slowness or the travel time per foot traveled through the formation, which is called delta t, and is usually measured in microseconds per ft.
Term
 What does the velocity of the p-wave depend on?
Definition
 Depends upon the elastic properties of the rock (matrix plus fluid), so the measured slowness varies depending upon the composition and microstructure of the matrix, the type and distribution of the pore fluid and the porosity of the rock.
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