A method may include obtaining core image data regarding a geological region of interest. The method may further include obtaining well log data regarding the geological region of interest from one or more wells. The method may further include determining a sliding window that corresponds to a predetermined window size. The method may further include determining various quantitative image attributes using the core image data, the well log data, and the sliding window. The quantitative image attributes may be determined in a continuous manner by moving the sliding window along the core image data. The method may further include generating predicted rock data for the geological region of interest using the quantitative image attributes, a machine-learning algorithm, and a machine-learning model.

The present disclosure relates to methods and apparatuses for acquiring multi-component gravity information for an earth formation. More particularly, the present disclosure relates to estimating the movement of fluid in an earth formation using at least one gravimeter configured to generate multi-component gravity information. The method may include estimating density changes in the earth formation. The method may include estimating a position of the at least one gravimeter. The apparatus may include a multi-component gravimeter configured to estimate gravity vectors for each vector component.

Methods comprising electronically receiving information of a reflection of a known first sound pulse, electronically receiving information of a reflection of a known second sound pulse, determining, by a processor, a change in a first property between a known first sound pulse and a reflection of the known first sound pulse, determining, by the processor, a change in a second property between a known second sound pulse and a reflection of the known second sound pulse, comparing, by the processor, the change in the first property of the first known sound pulse with the change in the second property of the second known sound pulse, and determining, by the processor, a condition of a well in response to the comparison of the change of the first property with the change of the second property are disclosed. Systems for determining a condition of a well are also disclosed.

A method for estimating formation slowness is provided. The method comprises forward modeling to compute formation slownesses based on a first method for orthorhombic media using stress magnitudes and third-order elastic constants as inputs, and forward modeling to determine formation slownesses analytically based on a second method using stress magnitudes, stress azimuth and third-order elastic constants as inputs. The first method may be based on Tsvankin method and the second method may be based on Christoffel method. The forward modeling may further use well configuration and reference moduli as inputs, and the results from the forward modeling may include formation slownesses, and at least one of vertical slownesses, anisotropic parameters, anellipticity indicators and fast shear azimuth. The method may further comprise assessing quality of the forward modeling based on results output from the forward modeling.

Some aspects of what is described here relate to seismic profiling techniques. A seismic excitation is generated in a first directional wellbore section in a subterranean region. A seismic response associated with the seismic excitation is detected by a fiber optic distributed acoustic sensing array in a second directional wellbore section in the subterranean region. Fluid movement in the subterranean region is identified based on the seismic response. In some cases, the fluid movement is identified in real time during well system operations.

Various examples are provided for wavefield extrapolation in anisotropic media. In one example, among others, a method includes determining an effective isotropic velocity model and extrapolating an equivalent propagation of an anisotropic, poroelastic or viscoelastic wavefield. The effective isotropic velocity model can be based upon a kinematic geometrical representation of an anisotropic, poroelastic or viscoelastic wavefield. Extrapolating the equivalent propagation can use isotopic, acoustic or elastic operators based upon the determined effective isotropic velocity model. In another example, non-transitory computer readable medium stores an application that, when executed by processing circuitry, causes the processing circuitry to determine the effective isotropic velocity model and extrapolate the equivalent propagation of an anisotropic, poroelastic or viscoelastic wavefield. In another example, a system includes processing circuitry and an application configured to cause the system to determine the effective isotropic velocity model and extrapolate the equivalent propagation of an anisotropic, poroelastic or viscoelastic wavefield.

Example computer-implemented methods and systems for geostatistical depth map based hydrocarbon exploration are disclosed. One example computer-implemented method includes obtaining one or more seismic attributes at multiple wellbores of a hydrocarbon reservoir. Multiple prior velocity maps of the hydrocarbon reservoir are determined based on the obtained one or more seismic attributes. Multiple velocities are determined based on the multiple prior velocity maps. Multiple depth map realizations are determined based on the multiple velocities. Multiple gross volumetric uncertainties of the hydrocarbon reservoir are determined based on the multiple depth map realizations. The multiple gross volumetric uncertainties are provided for hydrocarbon exploration of the hydrocarbon reservoir.

A method for estimating uncertainty in seismic-derived depth prognoses of a subsurface region includes receiving an initial velocity model of a subsurface region based on seismic data associated with the subsurface region, performing a seismic de-migration on initial post-migration seismic data obtained from the initial velocity model to obtain pre-migration seismic data, and perturbing one or more of the components of the initial velocity model to produce a plurality of perturbed velocity models that are each different from the initial velocity model. The method further includes performing a seismic migration of the pre-migration seismic data using the perturbed velocity model to obtain perturbed post-migration seismic data for each of the plurality of perturbed velocity models, estimating a depth error from a depth prognosis obtained from a selected subset of the perturbed velocity models based on characteristics of the perturbed post-migration seismic data, and estimating a depth uncertainty from the estimated depth error.

The present invention provides an intelligent geophysical data acquisition system and acquisition method for shale oil and gas optical fiber. A pipe string is arranged in a metal casing, and an external armored optical cable is fixed outside the metal casing; an, internal armored optical cable is fixed outside the pipe string; the external armored optical cable comprises a downhole acoustic sensing optical cable, two multi-mode optical fibers, a strain optical cable and a pressure sensor array, and further comprises horizontal ground acoustic sensing optical cables arranged in the shallow part of the ground according to an orthogonal grid, and artificial seismic source excitation points arranged on the ground according to the orthogonal grid.

This disclosure presents processes and systems for generating an image of a subterranean formation from seismic data recorded in a seismic survey of the subterranean formation. The seismic data is contaminated with low frequency noise in a low frequency band. Processes and systems reconstruct seismic data in the low frequency band of the seismic data to obtain low frequency reconstructed seismic data that is free of the low frequency noise. The low frequency reconstructed seismic data is used to construct a velocity model of the subterranean formation. The velocity model and the low frequency reconstructed seismic data are used to generate an image of the subterranean formation that reveals structures of the subterranean formation without contamination from the low frequency noise.