Patent application number | Description | Published |
20080298174 | Method for determining seismic anisotropy - The method disclosed is useful for estimating anisotropic properties of an earth formation. The method includes extracting travel time values of components of the acoustic wave induced from a downhole tool and reflected from a boundary bed formation. The method further includes obtaining a travel time ratio of the wave components and using the travel time ratio to estimate the anisotropic properties of the formation. | 12-04-2008 |
20090000859 | Method and Apparatus for Phased Array Acoustic Well Logging - A downhole acoustic logging tool uses a phased-array of transmitters and/or receivers to improve the signal level of compressional waves generated by the transmitters and propagating in the formation. It is emphasized that this abstract is provided to comply with the rules requiring an abstract which will allow a searcher or other reader to quickly ascertain the subject matter of the technical disclosure. It is submitted with the understanding that it will not be used to interpret or limit the scope or meaning of the claims. | 01-01-2009 |
20090005995 | Method and Apparatus for Characterizing and Estimating Permeability Using LWD Stoneley-Wave Data - Stoneley-wave data acquired in the LWD environment are used to characterize/estimate formation permeability. Real-time Stoneley-wave time-delay/slowness and center-frequency/attenuation data are used to indicate/characterize formation permeability even during drilling. The use of stabilizers mounted at the tool ends helps maintain the tool position from severe decentralization, reducing ambiguities in the permeability characterization/estimation. It is emphasized that this abstract is provided to comply with the rules requiring an abstract which will allow a searcher or other reader to quickly ascertain the subject matter of the technical disclosure. It is submitted with the understanding that it will not be used to interpret or limit the scope or meaning of the claims. | 01-01-2009 |
20090185446 | Identification of Stress in Formations Using Angles of Fast and Slow Dipole Waves in Borehole Acoustic Logging - Cross-dipole measurements are obtained in a borehole. By estimating a direction of polarization of the fast shear mode at low and high frequencies and comparing the estimated distances, a cause of anisotropy is established. Formation stresses and directions may be estimated. | 07-23-2009 |
20090205899 | Acoustic Imaging Away From the Borehole Using a Low-Frequency Quadrupole Excitation - Acoustic measurements made in a borehole using a multipole source are used for imaging a near-borehole geological formation structure and determination of its orientation. The signal to noise ratio (as defined by the ratio of the signal radiated into the formation to the axially propagating signal) depends upon the type of source (force or volume) and its position in the borehole (on the tool, in the fluid or on the borehole wall). | 08-20-2009 |
20090296522 | METHOD AND SYSTEM FOR DELINEATING A SECOND WELLBORE FROM A FIRST WELLBORE - Disclosed herein is a method of delineating a second wellbore from a first wellbore. The method includes, emitting acoustic waves from a tool in the first wellbore, receiving acoustic waves at the tool reflected from the second wellbore, and determining orientation and distance of at least a portion of the second wellbore relative to the tool. | 12-03-2009 |
20100085835 | NOVEL CURVE-FITTING TECHNIQUE FOR DETERMINING DISPERSION CHARACTERISTICS OF GUIDED ELASTIC WAVES - A method for estimating a slowness of an earth formation, the method including: transmitting acoustic energy into the earth formation using an acoustic source; receiving the acoustic energy with an array of acoustic receivers, each acoustic receiver being configured to provide acoustic waveform data related to the received acoustic energy; transforming the acoustic waveform data into a frequency domain to provide frequency domain data; calculating a slowness-frequency coherence function using the frequency domain data; selecting slowness dispersion data from peaks of the slowness-frequency coherence function; fitting a curve to the slowness dispersion data; and estimating the slowness from the curve. | 04-08-2010 |
20100097887 | Active Noise Cancellation Through the Use of Magnetic Coupling - Passive suppression of casing signals is used to improve the ability to measure formation velocities. Passive suppression includes the use of a magnet slidably coupled to the casing. | 04-22-2010 |
20100246325 | Method and Apparatus for Acoustic Impedance and P-Wave Anisotropy Measurements - Measurements of impedance are made using a piezoelectric transducer oriented at different angles to a formation bedding plane. The impedance measurements are then used to estimate the anisotropic velocity of the formation. | 09-30-2010 |
20100309748 | Method and Apparatus for Determining Radial Shear Velocity Variation From Dipole Acoustic Logging - A radial shear velocity profile of an earth formation is obtained by using dipole and/or cross-dipole measurements. The non-uniqueness in the inversion is addressed by using a constraint based on the fact that high-frequency dipole shear waves are mostly sensitive to the near-borehole shear velocity. | 12-09-2010 |
20120109528 | RADON MIGRATION OF ACOUSTIC DATA - Disclosed is a method implemented by a processor for imaging a formation penetrated by a borehole. The method includes: obtaining acoustic data in a depth-time domain using an acoustic downhole tool disposed at a depth in the borehole, the acoustic downhole tool having an acoustic source and an acoustic receiver; transforming the acoustic data in the depth-time domain into a Radon domain using a Radon transform; filtering the acoustic data in the Radon domain to increase a signal of interest in the acoustic data in the Radon domain; determining a location of a point in the formation that reflected acoustic energy emitted from the acoustic source to the acoustic receiver, the location of the point being represented in the Radon domain; and inverting the location of the point represented in the Radon domain into a radius-depth domain to image the formation. | 05-03-2012 |
20130070560 | Arranging Source-Receiver Orientations to Reduce High-Order Modes in Acoustic Monopole Logging - The present disclosure relates to methods and apparatuses for estimating a parameter of interest of an earth formation. The method may include using an acoustic sensor azimuthally positioned relative to a monopole acoustic source to reduce at least one high-order mode due to the monopole acoustic source. The monopole acoustic source may include one or more acoustic elements. The method may include generating a monopole acoustic pulse. The apparatus may include at least one acoustic source element and at least one acoustic sensor disposed on a housing configured for conveyance in a borehole. The at least one acoustic sensor may be azimuthally positioned relative to the at least one acoustic source to reduce at least one high-order mode. | 03-21-2013 |