Chevron U.s.a. Inc.

Triad National Security, LLC

Timothy James Ulrich, Ii

Harvey Edwin Goodman

Robert A Guyer

Marcel Remillieux

Paul Allan Johnson

Pierre-Yves Le Bas

James A Ten Cate

Esteban Rougier

Zhou Lei

Peter Roberts

Strain information may define strain of a material to stress. The strain of the material may be decomposed into classical strain, hysteretic strain, and residual strain. The classical strain, the hysteretic strain, and the residual strain may be used to facilitate modeling of the material. For example, the classical strain, the hysteretic strain, and the residual strain of a rock may be used to facilitate modeling of a subsurface region that includes the rock such as a reservoir simulation to predict hydrocarbon recovery.

Strain decomposition method

Structure information for a substance within a volume may be obtained. The structure information may characterize structural non-linearity of the substance within the volume. A structure model for the substance within the volume may be generated based on the structure information and/or other information. The structure model may simulate one or more characteristics of the substance within the volume. Presentation of information on the characteristic(s) of the substance within the volume may be effectuated based on the structure model and/or other information.

Systems and methods for modeling substance characteristics

A pulsed sinusoidal acoustic signal transmitted through a subsurface volume of a wellbore may be detected. A time-reversed acoustic signal of the pulsed sinusoidal acoustic signal may be transmitted through the subsurface volume of the wellbore. Transmission of the time-reversed acoustic signal through the subsurface volume of the wellbore may result in generation of focused acoustic signal in the subsurface volume of the wellbore. The focused acoustic signal in the subsurface volume of the wellbore may be detected, and the integrity of the wellbore may be determined based on the focused acoustic signal in the subsurface volume of the wellbore.

Time-reversed nonlinear acoustics for wellbore integrity characterization

Apparatus () and methods for combining time reversal and elastic nonlinearity of formation materials for qualtitatively probing for over-pressured regions down hole in advance of a well drilling bit, to determine the distance to the over-pressured region, and for accurately measuring pore pressure downhole in a formation, are described. Classical and reciprocal time reversal methods may be utilized to achieve these measurements.

Time-reversed nonlinear acoustics for downhole pressure measurements

Apparatus () and methods for measurement of pore pressure in rock formations through a metal borehole casing () after a well is cased and cemented, are described. Such measurements may be accomplished by using the Dynamic Acoustic Elasticity (DAE) method for characterizing nonlinear parameters by perturbing a selected rock formation region with a High Amplitude, Low Frequency (HALF) acoustic strain wave, and probing this region using a Low Amplitude, High Frequency (LAHF) acoustic wave (), (). Time reversal techniques () may be employed for focusing acoustic energy into the formation in the vicinity of the pipe or open hole. The change in wave speed of the probe pulses as the HALF induced strain wave oscillation propagates through the formation, as a function of the induced strain, may be used to determine the nonlinear elastic parameters &#x3b1;, &#x3b2;, &#x3b4;, and A of the pore pressure, from which the pore pressure may be determined in the region of the HALF wave.

Time-reversed nonlinear acoustic downhole pore pressure measurements

Apparatus and methods for measurement of pore pressure in rock formations through an open, or cemented and/or cased, borehole are described. Such measurements are achieved using the Dynamic Acoustic Elasticity (DAE) method for characterizing nonlinear parameters by perturbing a selected rock formation volume with a High Amplitude, Low Frequency (HALF) acoustic strain wave, and probing this volume using a Low Amplitude, High Frequency (LAHF) acoustic wave. Time reversal techniques may be employed for focusing acoustic energy Into the formation in the vicinity of the pipe or open hole.

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Los Alamos, NM, United States of America

Timothy James Ulrich, Ii