| |
FULL WAVE FORM SONIC
Tool design philosophy & applications
The full wave form sonic tool has been specifically designed for
the water, mining and geotechnical industries. Its specification
make it ideal for cement bond logs (CBL), for the measurement
of permeability index and as a specialist tool to carry out deep
fracture identification.
During logging, a series of high frequency sonic impulses are
emitted by the tool. Following their passage through the borehole
fluid and formations, these impulses are detected by receivers
at various distances from the transmitter. At each receiver, the
arriving waveform is digitally sampled according to a set of predefined
tool configuration parameters (sample rate, sampling period, gain).
The digitized waveforms are subsequently transmitted to the surface
acquisition and recording system.
Sonic logs are widely used to provide formation porosity/permeability
and mechanical properties.
Under suitable conditions S-wave and Stoneleys wave arrivals can
be detected.
The tool must only be operated in fluid-filled hole and does no
necessary need to be centralized.
Cased hole
• Detection
of poor or missing cement behind casing
Open-hole :
• Porosity
and permeability
• Lithology
identification
• Variation
of rock strength
• Elastic
moduli
•
Indication of fractures and permeability in hard rocks.
Main features
• High
energy of transmission to give a greater depth of penetration
•
Lower frequency of operation for greater penetration, and tube
wave recording especially for CBL
•
Ability to record a long wave train for Tube wave reflection acquisition,
which allows the determination of fracture aperture and permeability
index.
• Truly
modular construction allowing variation of receiver/transmitter
combinations
• Higher
logging speeds due to higher rate of data communication
FWS50 tool specifications
(PDF)
diameter
length
weight
Max temp
Max pressure
Borehole diameter
Number of transmitters
Number of receivers |
50mm /68mm
variable
variable
70°c
200 bar
minimum 60mm/78mm
1 or 2
2 to 8 |
Processing sonic data
|
