Method of acoustically detecting fractures in a borehole

Patent · Tue Jan 17 04:00:00 EST 1989

OSTI ID:6060566

Cheung, P S

A method of detecting fractures in earth formations penetrated by a borehole is described. The method includes the steps of: (a) moving a tool through the borehole, the tool processing transducers for transmitting and for receiving acoustic energy with at least one given transmitter-to-receiver spacing; (b) repetitively causing the tool to transmit acoustic energy as it is moved, and recording the acoustic energy received in the form of echo waveforms by a transducer together with the corresponding transmitter-to-receiver spacing, these echoes resulting from acoustic coupling between the transducers and the earth formations through the fluid filling the borehole; (c) selecting a window in the recorded waveform containing compression wave echoes and extracting therefrom a compression amplitude magnitude An, thereby providing at least one compression amplitude curve as a function of depth An(z), associated with a transmitter-to-receiver half-spacing sn; (d) isolating from the compression amplitude curve amplitude peaks having a width close to a predetermined value thereby obtaining at least one amplitude peak curve; and (e) determining the presence of fractures from the curves Pn(z + sn) and from the curve Pn(z - sn).

• Assignee: Schlumberger Technology Corp., Houston, TX
• Patent Number(s): US 4799200
• OSTI ID: 6060566
• Country of Publication: United States
• Language: English

Related Subjects

02 PETROLEUM
020200* -- Petroleum-- Reserves
Geology
& Exploration
03 NATURAL GAS
030200 -- Natural Gas-- Reserves
Geology
& Exploration
ACOUSTIC MEASUREMENTS
DETECTION
EQUIPMENT
EXPLORATION
FRACTURED RESERVOIRS
GEOLOGIC DEPOSITS
GEOLOGIC FRACTURES
GEOLOGIC STRUCTURES
GEOPHYSICS
MINERAL RESOURCES
NATURAL GAS DEPOSITS
PETROLEUM DEPOSITS
PROBES
RESOURCES
SONIC LOGGING
SONIC PROBES
TRANSDUCERS
WELL LOGGING
WELL LOGGING EQUIPMENT