Weatherford Technology Holdings, LLC

Weatherford/lamb, Inc.

Precision Energy Services, Inc.

Edwin K Roberts

Lucio Nelson Tello

Thomas Jay Blankinship

Marek Kozak

Thomas J Blankinship

Lucio N Tello

A method and apparatus for measuring parameters of a borehole using an acoustic logging system. By transmitting a high frequency acoustic signal essentially perpendicular to the major axis of a borehole casing using a transducer, the high frequency acoustic signal may produce one or more acoustic echoes. By receiving and analyzing a first acoustic echo from an inner wall of the borehole casing and at least one second acoustic echo from a back wall of the borehole casing, borehole parameters such as the impedance of the casing cement and the thickness of thicker borehole casings, up to and greater than 1 inch, may be determined.

Ultrasonic logging methods and apparatus for measuring cement and casing properties using acoustic echoes

Methods and systems for logging a wellbore having a casing are described. Acoustic energy, typically ultrasonic acoustic energy, is used to stimulate reverberation of the casing at a harmonic (for example, the second or third harmonic) of the resonance frequency of the casing. One or more acoustic sensors are used to measure acoustic signals generated by the casing reverberation. Parameters of the casing are calculated based on the measured acoustic signals adjusted by an adjustment factor determined by the particular harmonic. The use of harmonics instead of the fundamental resonance frequency allows wellbores with casings having walls thicker than 0.625 inches to be logged.

Ultrasonic cement and casing thickness evaluation

An ultrasonic scanner tool employs a transducer that excites a target plate at a known distance from the transducer. One side of the target plate forms a chamber that in operation is filled with wellbore fluid. On the other side of the target plate, a chamber is formed containing a vacuum or a fluid with a significantly lower acoustic impedance than the wellbore fluid and the target plate, allowing an improved measurement of the acoustic impedance of the wellbore fluid.

Apparatus and method for measuring the acoustic impedance of wellbore fluids

An acoustic logging system with a borehole tool comprising a transmitter assembly and an axially spaced receiver assembly. The transmitter and receiver assemblies are optionally rotatable with respect to each other, depending upon the embodiment of the logging system. The logging system is designed to measure, among other parameters, the velocity (or slowness) and amplitude of shear wave energy induced by the transmitter assembly within formation penetrated by the borehole. These parameters are extracted from full wave acoustic data responses of receiver elements comprising the receiver assembly, and are measured as a function of azimuth around the borehole. These parameters are subsequently used to determine anisotropic properties of the formation, such as the azimuthal direction of formation fracturing with respect to the well borehole. Optional rotation of the transmitter and receiver assemblies minimizes adverse effects of maintaining calibration and balance of multiple transmitters and receivers.

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Benbrook, TX, United States of America

Edwin K Roberts