Methods of analyzing stoneley waveforms and characterizing underground formations
AssigneeSchlumberger Technology Corporation
InventorsChristopher V. Kimball, Pawel Lewicki
Life of this patent
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Abstract
A method of analyzing Stoneley waveforms obtained in a well logging operation, includes analyzing the waveforms by means of multiparameter inversion using one or more externally provided parameters to obtain borehole fluid slowness and borehole fluid attenuation, and analyzing the Stoneley waveforms by multiparameter inversion using the borehole fluid slowness and borehole fluid attenuation and the externally provided parameters so as to determine a parameter, such as mobility, related to permeability of the formation being logged. Complex conjugate back propagation using a maximum likelihood/least mean squares error estimator or by applying Prony's method and fitting model-derived dispersion curves can be used to obtain mobility.
Claims13
A method of analyzing, sonic waveforms used for characterizing underground formations surrounding a borehole, comprising:
- a) transmitting and receiving sonic signals in the borehole;
- b) extracting Stoneley waveforms from received sonic signals;
- c) analyzing the Stoneley waveforms to determine borehole fluid slowness and borehole fluid attenuation;
- and
- d) using externally provided parameters and the borehole fluid slowness and borehole fluid attenuation determined from analysis of the Stoneley waveforms in the determination of a parameter related to the permeability of the formation.
Dependencies are inferred from the claim text.