Abstract: Seismic shear-wave survey systems and methods that employ inclined borehole pairs with directional detonations. If the boreholes have substantially equal inclinations in opposite azimuthal directions, the resulting signal traces can be combined to isolate shear wave energy contributions, thereby offering potentially enhanced resolution and reduced-complexity interpretation. The boreholes may be cased to ensure repeatability for, e.g., monitoring of reservoir fracturing, treatments, and/or drainage. The directional charges may be immersed to improve coupling of seismic energy into the formation.

Abstract: Vertical Seismic Profile (VSP) analysis is a technique commonly used to conduct geophysical surveys of subterranean features. The processing of a VSP includes several steps, usually including a final step of depth migration. In order to properly process and image VSP data using depth migration, a velocity model of the subsurface must be known or derived. A variety of criteria can be used to ascertain whether the velocity used for migration is accurate.

Abstract: Vertical Seismic Profile (VSP) analysis is a technique commonly used to conduct geophysical surveys of subterranean features. The processing of a VSP includes several steps, usually including a final step of depth migration. In order to properly process and image VSP data using depth migration, a velocity model of the subsurface must be known or derived. A variety of criteria can be used to ascertain whether the velocity used for migration is accurate.

Abstract: Seismic shear-wave survey systems and methods that employ inclined borehole pairs with directional detonations. If the boreholes have substantially equal inclinations in opposite azimuthal directions, the resulting signal traces can be combined to isolate shear wave energy contributions, thereby offering potentially enhanced resolution and reduced-complexity interpretation. The boreholes may be cased to ensure repeatability for, e.g., monitoring of reservoir fracturing, treatments, and/or drainage. The directional charges may be immersed to improve coupling of seismic energy into the formation.

Abstract: Method of interpolating additional seismic traces between existing seismic traces obtained during the exploration of a subsurface formation. Seismic traces are recorded upon a datum surface in accordance with standard seismic data acquistion methods. Forward and backward wave equation datuming of the data set at the same velocity estimates new measurements for originally acquired data deemed unsatisfactory by propagating measured seismic traces to a fictitious datum plane using wave theory to create a second set of seismic traces and datuming the second set of seismic traces, again using wave theory, back to the original datum plane to create a third set of seismic traces. The third set of seismic traces will include new seismic traces to be used in place of the originally acquired unsatisfactory data.

Abstract: A borehole logging tool includes at least one acoustic energy transmitter and at least one spaced apart acoustic energy receiver. Acoustic energy signals travel from the transmitter to the receiver directly through the subsurface formation adjacent the borehole and indirectly through reflections from subsurface formation changes below the bottom of the borehole. The difference in travel times of the directly arriving and indirectly arriving signals are determined for like acoustic waveforms as a measure of the depth of the subsurface reflecting formations below the borehole.

Abstract: A well logging tool employing at least one transmitter and at least one receiver is incrementally advanced through a borehole. A plurality of recorded well log traces from successive ones of the incremental depth points for a single transmitter-receiver pair are correlated to identify a moveout trend for the recorded waveforms about the measured arrival time of the waveform on the center trace of such plurality of traces. A second correlation of the center trace of the plurality of traces with the next successive depth trace is carried out in accordance with the identified moveout trend to determine the arrival time of the acoustic waveform on such next successive depth trace with respect to the measured arrival time of the center trace.