Precision Energy Services, Inc.

Computalog Research, Inc.

Weatherford Technology Holdings, LLC

Computalog USA Inc.

Weatherford/lamb, Inc.

Lucio Nelson Tello

Thomas Jay Blankinship

Edwin K Roberts

Elan Yogeswaren

Edwin Kamm Roberts

Stanley R Thomas, Jr

Allen R Young

Peter J Schoch

Gregory J Caston

Sarah D Molder

Gerald T Alford

Marek Kozak

Freddie L Sellers

Thomas J Blankinship

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

A method and apparatus for normalizing an acoustic wellbore tool by correcting measured sector acoustic signals due to changes in pressure and temperature downhole, the method and apparatus comprising an acoustic wellbore tool having at least one monopole transmitter and monopole receiver, and one or more sector transmitters and receivers disposed along the longitudinal axis of the tool, determining the attenuation values of received monopole and sector acoustic signals, determining a correction ratio using an average sector attenuation value and a theoretical attenuation value, and correcting the sector acoustic signals using the correction ratio.

Normalization of sector amplitudes using monopole amplitudes

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 that measures distribution of foam cement and other material in a casing-borehole annulus. The distribution is preferably displayed as map. A borehole tool utilizes at least one acoustic transducer with a known frequency response and mounted on a rotating scanning head that is pointed essentially perpendicular to the borehole wall. The response of the transducer is used to measure an original impedance map of material within the borehole-casing annulus. A fast Fourier transform is used to generate a FFT map from the data comprising the original impedance map. The original impedance map is then combined with the FFT map using logic rules to obtain a final impedance map that is indicative of material within the casing-borehole annulus.

Method and apparatus for logging foam cement in cased boreholes

An acoustic borehole logging system for generation and detection of multipole modes used to determine elastic properties of earth formations characterized as inhomogeneous anisotropic solids. The system concurrently generates and senses monopole, dipole, quadrupole and any higher order pole in the borehole/formation system in order to characterize the elastic properties and stress state of material penetrated by the borehole. Multipole modes of all orders are induced simultaneously without the need for separate transmitter and receiver systems. Performance of the logging system is not compromised due to eccentering of the axis of the tool in the borehole, tool tilt with respect to the axis of the borehole, or mismatch of response sensitivity of multiple receivers within the tool. The system comprises apparatus for generating and sensing acoustic signals in a borehole in an earth formation, and further comprises a processing method by which the sensor response signals are processed and analyzed to obtain desired formation parameters of interest.

Borehole apparatus and methods for simultaneous multimode excitation and reception to determine elastic wave velocities, elastic modulii, degree of anisotropy and elastic symmetry configurations

Methods and apparatus for in situ, continuous, automatic, and real-time acoustic impedance calibration of a transducer in an acoustic logging system. By taking the frequency characteristics of the ultrasonic transducer which are present in the internal casing reflection and convolving them with the frequency characteristics of the casing being logged, a theoretical model is created with a theoretical acoustic impedance fluid producing a theoretical free pipe signal at each measure point. The measured signal is then compared to the theoretical free pipe signal thereby yielding a calibrated acoustic impedance value for at each measure point. The only model employed is in the theoretical calculation of spectrum characteristics of free pipe.

Ultrasonic logging methods and apparatus for automatically calibrating measures of acoustic impedance of cement and other materials behind casing

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.

Method and apparatus for azimuthal logging of shear waves in boreholes using optionally rotatable transmitter and receiver assemblies

A free point tool has at least one sensor to measure deformation of a stuck conduit in a borehole. A set of anchors is located adjacent to and on each side of the sensor. The anchors include anchor arms that move from a stowed position to an extended position. Each of the anchor arms has a pad, which pad has a contact face. The contact face is structured and arranged to engage the conduit. The pad is coupled to the respective anchor arm in an articulating manner, such as by a pin joint or a ball and socket joint. The pad can be easily coupled to or disconnected from the arm. This allows the pad to be selected for the downhole conditions, including conduit physical characteristics and environmental conditions downhole. The anchors also include cam arms coupled between the anchor arms and an actuator. There are provided at least two sets of anchor linkages of cam arms and anchor arms so as to adapt to the conduit inside diameter.

Method and apparatus for anchoring tool in borehole conduit

The acoustic impedance of a fluid in a borehole is determined by gating a reflected acoustic signal into a plurality of time slots, and comparing received energies of the signal for the time slots to obtain a value indicative of the acoustic impedance of the fluid. The value may be normalized to yield the acoustic impedance of the fluid using the acoustic impedance of, e.g., water as a calibration point. The acoustic pulse may be generated using a transducer immersed in an intermediate fluid contained within a chamber defined in part by a plate in contact with the borehole fluid and having a thickness such that a mechanical resonance frequency of the plate in a thickness mode is substantially equal to a resonance frequency of the transducer. The sonic velocity of the fluid is also measured and, when combined with the acoustic impedance, is used to determine fluid density.

Method and apparatus for acoustics logging of fluid density and wet cement plugs in boreholes

A method of determining the acoustic impedance of a fluid in a borehole, by gating a reflected acoustic signal into a plurality of time slots, and comparing received energies of the signal for the time slots to obtain a value indicative of the acoustic impedance of the fluid. The value may be normalized to yield the acoustic impedance of the fluid using the acoustic impedance of, e.g., water as a calibration point. The comparison is performed by comparing a ratio of an integration of a first ring down time slot and a second ring down time slot, to an integration of an internal reflection time slot. The acoustic pulse may be generated using a transducer immersed in an intermediate fluid contained within a chamber defined in part by a plate in contact with the borehole fluid and having a thickness such that a mechanical resonance frequency of the plate in a thickness mode is substantially equal to a resonance frequency of the transducer. The sonic velocity of the fluid is also measured and, when combined with the acoustic impedance, is used to determine the fluid density.

Method and apparatus for acoustic logging of fluid density and wet cement plugs in boreholes

Method and apparatus for acoustic logging of fluid density and wet

An acoustic logging tool having an acoustic transmitter and at least one acoustic receiver longitudinally spaced from the transmitter is lowered into a borehole fluid within a tubular member having a known resonant frequency. A pulse of acoustic energy is then transmitted into the tubular member, and acoustic energy traversing the tubular member and formation is detected at the acoustic receiver. A frequency domain transformation is performed on the detected acoustic energy and a cement bond evaluation is performed by comparing transformed detected acoustic energy amplitudes within a predetermined range of the resonant frequency of the tubular member, effectively filtering out acoustic energy which traverses the formation surrounding the tubular member.

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Benbrook, TX, United States of America

Lucio Nelson Tello