摘要:
A method of correlating seismic events associated with different types of seismic transmission modes and includes calculating a shift estimate between a first set of seismic events or attributes associated with the seismic events attributable to one type of transmission mode and a second set of seismic events or attributes associated with the seismic events attributable to a different type of transmission mode using a smoothed version of at least one of the sets of seismic events or attributes associated with the seismic events, and updating the shift estimate using a less severely smoothed or unsmoothed version of the at least one set of seismic events or attributes associated with the seismic events. A related computer system and computer program products associated with the method are also described.
摘要:
A method for estimating near-surface material properties in the vicinity of a locally dense group of seismic receivers is disclosed. The method includes receiving seismic data that has been measured by a locally dense group of seismic receivers. Local derivatives of the wavefield are estimated such that the derivatives are centered at a single location preferably using the Lax-Wendroff correction. Physical relationships between the estimated derivatives including the free surface condition and wave equations are used to estimate near-surface material properties in the vicinity of the receiver group. Another embodiment of the invention is disclosed wherein the physical relationships used to estimate material properties are derived from the physics of plane waves arriving at the receiver group, and the group of receivers does not include any buried receivers.
摘要:
The present invention provides for a method of processing mode converted seismic data. The method comprises acquiring seismic data and determining a P-wave velocity model for the seismic data. An S-wave velocity model is determined from the P-wave velocity model. The mode converted seismic data are depth migrated forming CIP mode converted seismic data gathers. Corrected S-wave velocities are determined from near-offset data of the CIP gathers which corrects the depth migrated mode converted seismic data to the P-wave velocity model depth. A correction factor is provided and the iterating with the method quickly converges to a solution. This invention provides an efficient method of updating the shear wave velocity model for prestack depth migration of mode-converted data.
摘要:
A method for estimating near-surface material properties in the vicinity of a locally dense group of seismic receivers is disclosed. The method includes receiving seismic data that has been measured by a locally dense group of seismic receivers. Local derivatives of the wavefield are estimated such that the derivatives are centered at a single location preferably using the Lax-Wendroff correction. Physical relationships between the estimated derivatives including the free surface condition and wave equations are used to estimate near-surface material properties in the vicinity of the receiver group. Another embodiment of the invention is disclosed wherein the physical relationships used to estimate material properties are derived from the physics of plane waves arriving at the receiver group, and the group of receivers does not include any buried receivers
摘要:
A method and apparatus for reliable and low-cost acquisition of offset checkshot survey data using tube wave conversion. An acoustic receiver is deployed in a fluid-filled well, preferably at or near the top thereof. At least one tube-wave conversion point is used, such as an interface between two immiscible fluids, a change in casing geometry or a wellbore constriction. The traveltime of a tube wave from the tube-wave conversion point to the acoustic receiver is determined. Then, a seismic signal is generated at a laterally offset location. The total seismic signal traveltime along a raypath from the source location to the tube-wave conversion point and then upwardly through the fluid-filled well to the acoustic receiver is measured. The previously determined tube-wave traveltime from the conversion point to the acoustic receiver is then subtracted from the total traveltime to obtain the seismic signal traveltime from the source location to the tube-wave conversion point.
摘要:
The instant invention provides a method for processing converted-wave data into interpretable images using a compact two-parameter model. The method broadly comprises the steps of: collecting both P-wave and converted-wave seismic data; identifying the arrival times of the P-wave and the converted-wave data; computing the vertical velocity ratio from the arrival time data; computing the moveout velocity ratio from the corresponding moveout velocities; computing the effective velocity ratio from the vertical velocity ratio and the moveout velocity ratio; and computing the conversion point from the short-spread P-wave moveout velocity for each reflector, from the effective velocity ratio, the C-wave moveout velocity ratio, and from the arrival time data.
摘要:
Production capability of cased hole perforations in a cased completed well lined with a casing in an under-pressured gas producing reservoir is tested. A sonde of a dipole shear or array sonic (full waveform) acoustic well logging tool is moved in a well bore of the cased completed well in the reservoir across a depth interval of interest, which covers cased hole perforations zones in the reservoir. The well logging sonde has in it an acoustic energy source and acoustic energy receivers. Responses are logged at depth intervals of interest to the transit of Stoneley waves along the casing walls from the acoustic energy source to the acoustic energy receivers. Measures of characteristics (e.g., travel time and attenuation) of the Stoneley wave are obtained. The responses are then processed to indicate production capability of the cased hole perforations.
摘要:
A system and method of processing seismic data obtained using a plurality of towed single-component receivers in a marine environment is described, the towed single-component receivers configured to measure compressional P waves. The method comprises retrieving seismic data from a storage device, the seismic data comprising P-P data and shear mode data, wherein the P-P data and shear mode data were both received at the towed single-component receivers configured to measure compressional P waves to generate the seismic data. The method further comprises processing the seismic data to extract SV-P shear mode data and generating shear mode image data based on the extracted shear mode data.
摘要:
A system and method of processing seismic data obtained using a plurality of towed single-component receivers in a marine environment is described, the towed single-component receivers configured to measure compressional P waves. The method comprises retrieving seismic data from a storage device, the seismic data comprising P-P data and shear mode data, wherein the P-P data and shear mode data were both received at the towed single-component receivers configured to measure compressional P waves to generate the seismic data. The method further comprises processing the seismic data to extract SV-P shear mode data and generating shear mode image data based on the extracted shear mode data.
摘要:
A system and method of processing seismic data obtained using a surface-based receiver configured to measure vertical movement of the Earth includes retrieving seismic data from a storage device, the seismic data comprising P-P data and shear mode data. The P-P data and shear mode data were both received at a surface-based receiver configured to measure vertical movement of the Earth to generate the seismic data. The system and method further include processing the seismic data to extract the shear mode data and generating a shear mode image based on the extracted shear mode data.