Abstract: Embodiments of determining a vertically transverse isotropy (VTI) anisotropy along a horizontal section of a wellbore drilled into a formation are provided. One embodiment comprises determining elastic constants C11, C44, and C66 of the horizontal section and determining a vertical compressional slowness of the horizontal section corresponding to an elastic constant C33 of the horizontal section using a model with a condition. The model is built using second sonic log data and second density log data of the vertical wellbore. The condition is that the shear slowness (DTS) of the vertical wellbore is equal to the vertically polarized shear slowness (DTSV) of the horizontal section. The embodiment further comprises determining a VTI anisotropy along the horizontal section using the elastic constants C11, C44, C66, and C33 of the horizontal section.

Abstract: One embodiment includes receiving seismic data from a plurality of seismic sensors located proximate to a build section of a wellbore that is drilled into a subsurface. The seismic data is recorded for a plurality of seismic waves, at different angles, sent from a plurality of seismic sources towards the plurality of seismic sensors. Locations of the plurality of seismic sources relative to locations of the plurality of seismic sensors are such that the plurality of seismic waves are essentially planar at the plurality of seismic sensors. The subsurface is essentially homogenous proximate to the build section. For at least a portion of the plurality of seismic waves, the embodiment includes determining a slowness vector for each seismic wave, and determining a phase velocity and a phase angle. The embodiment includes determining at least one anisotropic parameter value for the build section, determining a vertical velocity value, and using these.

Abstract: Embodiments of determining a vertically transverse isotropy (VTI) anisotropy along a horizontal section of a wellbore drilled into a formation are provided. One embodiment comprises determining elastic constants C11, C44, and C66 of the horizontal section and determining a vertical compressional slowness of the horizontal section corresponding to an elastic constant C33 of the horizontal section using a model with a condition. The model is built using second sonic log data and second density log data of the vertical wellbore. The condition is that the shear slowness (DTS) of the vertical wellbore is equal to the vertically polarized shear slowness (DTSV) of the horizontal section. The embodiment further comprises determining a VTI anisotropy along the horizontal section using the elastic constants C11, C44, C66, and C33 of the horizontal section.

Abstract: One embodiment includes receiving seismic data from a plurality of seismic sensors located proximate to a build section of a wellbore that is drilled into a subsurface. The seismic data is recorded for a plurality of seismic waves, at different angles, sent from a plurality of seismic sources towards the plurality of seismic sensors. Locations of the plurality of seismic sources relative to locations of the plurality of seismic sensors are such that the plurality of seismic waves are essentially planar at the plurality of seismic sensors. The subsurface is essentially homogenous proximate to the build section. For at least a portion of the plurality of seismic waves, the embodiment includes determining a slowness vector for each seismic wave, and determining a phase velocity and a phase angle. The embodiment includes determining at least one anisotropic parameter value for the build section, determining a vertical velocity value, and using these.

Abstract: At least one elastic parameter of a region of interest of a formation is modeled, and at least one velocity measurement acquired in a wellbore extending in the formation is predicted based on the modeling. The model is refined based on the predicted velocity measurement(s) and based on at least one actual measurement acquired from within a single wellbore.

Abstract: A method for estimating subsurface elastic parameters is described herein. One or more slowness vectors may be determined based on a vertical seismic profile of a subsurface area. A model containing anisotropy parameters and a well deviation estimate may be generated based on survey data. The slowness vectors may be corrected for the well deviation estimate based on the model. One or more modeled slowness vectors may be calculated using the corrected slowness vectors and the anisotropy parameters in the model.

Abstract: Methods and related systems are described relating to processing subsurface sonic and seismic data. The described techniques use anisotropy estimates derived from a walkaway VSP to calibrate elastic properties derived from sonic logs. An empirical relationship between the sonic derived anisotropy parameters is modified until the upscaled elastic properties from the sonic log data best matches the anisotropy parameters measured with the walkway VSP. The result is a set of elastic constants consistent with the walkaway VSP measurements.

Abstract: Methods and systems for determining reservoir parameters of subterranean formations. A tool is configured or designed for deployment at at least one depth in a borehole traversing a subterranean formation. The tool comprises at least one sensor configured or designed for sensing rotational components of a seismic wavefield deployed in an array comprising at least one sensor configured or designed for sensing translational components of a seismic wavefield. A computer is in communication with the tool and a set of instructions executable by the computer that, when executed, process the seismic measurements and derive parameters relating to the formation based on the seismic measurements.

Abstract: At least one elastic parameter of a region of interest of a formation is modeled, and at least one velocity measurement acquired in a wellbore extending in the formation is predicted based on the modeling. The model is refined based on the predicted velocity measurement(s) and based on at least one actual measurement acquired from within a single wellbore.

Abstract: Methods and related systems are described relating to processing subsurface sonic and seismic data. The described techniques use anisotropy estimates derived from a walkaway VSP to calibrate elastic properties derived from sonic logs. An empirical relationship between the sonic derived anisotropy parameters is modified until the upscaled elastic properties from the sonic log data best matches the anisotropy parameters measured with the walkway VSP. The result is a set of elastic constants consistent with the walkaway VSP measurements.

Abstract: To process subterranean survey data, measurement data is collected by a receiver positioned in deep water, where the collected measurement data is responsive to signals emitted by at least one signal source located at or near an air-water interface of the body of water. The measurement data is processed to reduce a predetermined signal component.

Abstract: A method for estimating subsurface elastic parameters is described herein. One or more slowness vectors may be determined based on a vertical seismic profile of a subsurface area. A model containing anisotropy parameters and a well deviation estimate may be generated based on survey data. The slowness vectors may be corrected for the well deviation estimate based on the model. One or more modeled slowness vectors may be calculated using the corrected slowness vectors and the anisotropy parameters in the model.

Abstract: Methods and systems for determining reservoir parameters of subterranean formations. A tool is configured or designed for deployment at at least one depth in a borehole traversing a subterranean formation. The tool comprises at least one sensor configured or designed for sensing rotational components of a seismic wavefield deployed in an array comprising at least one sensor configured or designed for sensing translational components of a seismic wavefield. A computer is in communication with the tool and a set of instructions executable by the computer that, when executed, process the seismic measurements and derive parameters relating to the formation based on the seismic measurements.

Abstract: To process subterranean survey data, measurement data is collected by a receiver positioned in deep water, where the collected measurement data is responsive to signals emitted by at least one signal source located at or near an air-water interface of the body of water. The measurement data is processed to reduce a predetermined signal component.

Abstract: To perform a survey of a subterranean structure behind a subsea surface, at least one sensor module is provided in a subsea environment, where the at least one sensor module comprises at least one magnetic field sensor. Measurement data is received from the magnetic field sensor, and an electric field along a particular direction is determined based on the measurement data to perform the survey of the subterranean structure, wherein the particular direction is generally orthogonal to the subsea surface.