Mobil Oil Corporation

Adam Bednarczyk

Robert E Maute

Laird B Thompson

David Symmons

A method and apparatus is disclosed to identify fluid hydrocarbon flow rates in a flow line such as a pipeline or a producing oil well having a unidirectional fluid flow including moving an acoustic tool through a flow line. Acoustic energy is transmitted into the fluid flow. The acoustic energy is then received when it is reflected back by interfaces within the fluid flow. The reflected acoustic energy is transformed into electrical signals. The electrical signals are rectified. The amplitude peaks of the rectified electrical signals are determined. The travel times of the amplitude peaks are also determined. The amplitude peaks and the time values are used to determine hydrocarbon gas and the hydrocarbon liquid in the hydrocarbon fluid flow in the oil well. A transducer within the acoustic tool rotates three hundred sixty degrees six times per second. This enables us to obtain holdup and velocities for the total flow around the tool even in non ideal operating conditions such as deviated wells.

Multi-phase fluid flow measurement

A method and apparatus for determining the various components of a multi-phase fluid flow in a defined area includes using an acoustic transceiver tool to direct a beam of acoustic energy toward the fluid flow in a producing well or a horizontal line. A signal is generated when the reflection of the beam of acoustic energy returns and is detected. The signal is rectified and recorded as a measure of oil flow rate within the well. The amplitude peaks are identified and areas around each peak are determined. Two areas of the rectified signal are defined relating to the determined amplitude peaks. The rectified signal under each area is integrated to provide an indication of fluid flow and the strength of the signal reaching the casing. A ratio is determined from the integration results of the two areas. The magnitude of this ratio provides an indication of the extent of the presence of gas in the fluid flow. In an alternate embodiment, the detected signal is rectified and the envelop of the rectified full wavelet of returning signals is taken, reducing the frequency of the signal. The envelop of the reflection signals are recorded as a measure of oil flow rate within the defined area. The amplitude peaks are identified and areas around each peak are defined. Each defined area of the envelop is integrated to determine the portion of the flow that is liquid. A ratio is determined from the integration results of the two areas. The magnitude of this ratio provides an indication of the extent of the presence of gas in the fluid flow.

Acoustic logging to identify oil flow rate

In a borehole logging tool, a hot wire or hot film anemometer measures fluid flow entering or exiting the borehole at the wall of the borehole. The logging tool has open sensing pads mounted on the arms to place the sensor pads at the wall. The sensor pads are open to fluid flow to provide minimum disruption of flow. Other sensors measure flow direction, capacitance, and temperature.

Method of monitoring fluids entering a wellbore

A borehole televiewer logging tool employs a transducer assembly having a transmitter of acoustic energy pulses and a receiver of acoustic energy pulses representing reflections of the transmitted acoustic energy pulses from the walls of a borehole traversing a subsurface formation. The transducer assembly is rotated within the borehole and also advanced along the borehole. The received reflection signals are corrected for amplitude modulation resulting from oblique angles of incidence of the transmitted acoustic energy pulses when the logging tool is off-center of the borehole, is in an eliptical borehole, or is tilted from the vertical axis of the borehole. The corrected reflection signals modulate an image display so that the full 360.degree. of the borehole wall can be delineated.

Method and apparatus for logging the characteristics of materials

A method for improving the accuracy of neutron detectors is disclosed wherein a predetermined threshold level, by analysis of a neutron and gamma relative distribution curve, is set and all amplitudes below this predetermined minimum are removed from a neutron detector total count.

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Carrollton, TX, United States of America

Adam Bednarczyk