Borehole televiewer for fracture detection and cement evaluation

Patent · Tue Feb 12 04:00:00 EST 1991

OSTI ID:5802749

Rambow, F H.K.; Clerke, E A

This patent describes a method for acoustically logging a borehole in the earth to detect anomalies in the earth formation beyond the wall of the borehole. It comprises generating a plurality of narrow beam acoustic pulses with a rotating transducer at a first location in the borehole, wherein the complete circumference of the borehole at the first location is scanned by the pulses; receiving at the first location the reflected responses of the acoustic pulses and producing a first electrical signal; receiving at a second location vertically spaced from the first location the reflected responses of the acoustic pulses with a single element annular thin film omnidirectional receiver and producing a second electrical signal; recording the first and second electrical signals to provide a visual display of the elapsed time between the generating of the acoustic pulses and the occurrence of reflection events from the anomalies in the first and second electrical signals; and analyzing the display to locate the position of the anomalies.

• Assignee: Shell Oil Co., Houston, TX (USA)
• Patent Number(s): US 4992994; A
• Application Number: PPN: US 7-330384
• OSTI ID: 5802749
• Country of Publication: United States
• Language: English

Related Subjects

02 PETROLEUM
020200* -- Petroleum-- Reserves
Geology
& Exploration
ACOUSTIC MONITORING
BOREHOLES
CAVITIES
GEOLOGIC FRACTURES
GEOLOGIC STRUCTURES
GEOLOGIC SURVEYS
MONITORING
SURVEYS
TECHNOLOGY ASSESSMENT
WELL LOGGING