Abstract: A method of three-component seismology wherein seismic energy induced vertical, radial and transverse particle movement is detected at plural spaced positions along a survey line to produce orthogonal data signals, and the different orthogonal data signals are variously processed both separately and interactively to develope novel signal relationships which improve indication and identification of steeply dipping reflections, out-of-plane reflections, and the like.

Abstract: Seismic traces are stacked in a plurality of orthogonal measures to form multiple stacked traces at a positive offset. The stacking process determines the apparent velocities as functions of the travel time at the positive offset. The interval acoustic velocity of the first layer is then determined from knowledge of surface topography, source-receiver offset, two-way travel times and the first reflector apparent velocities. The first layer velocity information enables the incident and emergent angles of the raypaths at the surface to be calculated, as well as enabling the dip angles and spatial coordinates of the reflection points on the first reflecting boundary to be determined.Seismic data corresponding to the second reflecting boundary are then spatially mapped to the first reflecting boundary by ray tracing and by a new method for calculating the apparent velocities at the first boundary. The process is repeated for each succeedingly deeper boundary.

Abstract: A method for determining the position of a subterranean plane reflector relative to a known location on the earth surface from unprocessed seismic data received at a number of colinear acoustic receiver locations. A traveltime curve associated with the reflector is identified from the seismic data. From two points on the traveltime curve, a signal indicative of the reflector's dip angle is generated. Using the dip angle signal, signals indicative of the position of each imaged point of the reflector are generated. The inventive method assumes knowledge of the average velocity of seismic waves in the subterranean formation above the reflector, and that such formation region can adequately be considered to have constant velocity equal to such average velocity. The method may be applied to process raw data generated during a vertical seismic profiling operation.

Abstract: By using wave tracking rather than a downward continuation concept, two sets of elastic wave fields (one generated by a seismic source, the other recorded by multicomponent geophones) are migrated separately and are then imaged. The process is repeated for common shot gathers, and then the images (associated with each common midpoint gather), are stacked.As a consequence of wave tracking, migration operations are preferably performed in the time domain using finite difference discretization equations involving vector properties of the fields but without having to reduce the latter to one-way wave equations.

Abstract: In seismic exploration, seismic reflection signals are obtained along a line of exploration. These seismic reflection signals are time shifted to correct for moveout caused by horizontal dipping and diffraction subsurface events. These connected signals are stacked with a dip independent velocity parameter to provide a zero source-to-receiver seismic record section enhanced in signal-to-noise ratio.

Abstract: In a seismic recording and processing system in which a line of sources and a separate line of receivers are provided and each of the source operations from each of the source points is recorded on all receiver points. A method is described for determining the differential static correction between each adjacent pair of source points in terms of the differences in travel times from each pair of source points, to all pairs of receiver points. This is provided even though the lines of source points and receiver points may be parallel to or at angles to each other, and the spacings of source points and receiver points in their separate lines may be the same or different.

Abstract: A method for deriving seismic information of more generalized nature over a relatively large and previously unexplored expanse of land to determine relevant strike, dip, velocity and related information. The method consists of the placing of a plurality of seismic sources and receivers in respective lines arranged in a cross pattern, each line being generally at right angles each to the other, and thereafter exciting the sources and recording the received energy for further processing to derive the strike, dip and velocity information for selected strata by using travel times of signal return.

Abstract: A multiple coverage seismic exploration technique provides for a plurality of seismic trace recordings along a line of exploration. From these recordings, sets of common-offset-distance traces are gathered. Initial estimates are made of the apparent dips associated with the seismic reflection signals across each set of common-offset-distance traces. These initial dip estimates are smoothed and the sets of common-offset-distance traces filtered along the apparent dips associated with the smoothed dip estimates to enhance the signal-to-noise ratio of the primary reflection signals.

Abstract: In seismic exploration, linear, multiple fold, common depth point sets of seismograms with three dimensional reflection geometry are used to determine the dip and strike of the subsurface reflecting interfaces and the average velocity of the path of the seismic energy to the reflecting interface. The reflections in each set appear with time differences on a hyperbola with trace spacings determined by the source receiver coordinate distance along the lines of exploration. The offset of the apex of this hyperbola is determined from a normal move-out velocity search of the type performed on two dimensional CDP sets. This search identifies the correct stacking velocity and hyperbola offset which are used to determine dip, strike and average velocity.

Abstract: Common depth point seismic signals from a plurality of seismic receivers are recorded on a field recorder. A first time shifter corrects the seismic signals for multiple normal moveout. A linear dip filter rejects unwanted multiple reflection signals. A second time shifter reverses the multiple normal moveout correction of the first time shifter. A third time shifter corrects the primary reflection signals for normal moveout. The primary reflection signal are then stacked and recorded as a composite common depth point seismic signal.