Claims Analysis
Total Claims: 23
Claim 1
Independent Claim
178 words
A method for deriving a three-dimensional seismic image from two-dimensional seismic data arranged according to a plurality of shot lines in a survey area, comprising the steps of: representing said seismic data in a representation which corresponds to the spatial relationship of the shot lines in the survey area; for each portion of said seismic data corresponding to each of said shot lines, performing a two-dimensional migration thereof to generate migrated seismic data in the form of a plurality of migrated traces corresponding to each shot line; selecting a plurality of image points in said representation, said image points corresponding to points in said survey area; for each of said selected image points, performing the substeps of: selecting the migrated trace for each of said plurality of migrated shot lines that is closest to the image point in said representation; and for each selected migrated trace, performing a migration with respect to the image point; and forming a migrated three-dimensional image using the results of said migrations of said selected migrated traces with respect to said image points.
Claim 2
Independent Claim
178 words
A method for deriving a three-dimensional seismic image from two-dimensional seismic data arranged according to a plurality of shot lines in a survey area, comprising the steps of: representing said seismic data in a representation which corresponds to the spatial relationship of the shot lines in the survey area; for each portion of said seismic data corresponding to each of said shot lines, performing a two-dimensional migration thereof to generate migrated seismic data in the form of a plurality of migrated traces corresponding to each shot line; selecting a plurality of image points in said representation, said image points corresponding to points in said survey area; for each of said selected image points, performing the substeps of: selecting the migrated trace for each of said plurality of migrated shot lines that is closest to the image point in said representation; and for each selected migrated trace, performing a migration with respect to the image point; and forming a migrated three-dimensional image using the results of said migrations of said selected migrated traces with respect to said image points.
Claim 3
Dependent Claim
21 words
The method of claim 1, wherein said step of performing a two-dimensional migration comprises the step of performing a Kirchhoff migration.
Claim 4
Dependent Claim
19 words
The method of claim 2, wherein said step of performing a Kirchhoff migration uses only the far-field term thereof.
Claim 5
Dependent Claim
31 words
The method of claim 1, wherein said step of performing a migration on each selected migrated trace with respect to the image point comprises the step of performing a Kirchoff migration.
Claim 6
Dependent Claim
23 words
The method of claim 4, wherein said step of performing a Kirchhoff migration uses only the far-field term thereof of said Kirchhoff migration.
Claim 7
Dependent Claim
12 words
The method of claim 1, wherein said representation is in (x,y,t) space.
Claim 8
Dependent Claim
17 words
The method of claim 1, wherein each of said steps of performing migrations comprise performing diffraction summations.
Claim 9
Dependent Claim
29 words
The method of claim 1, wherein each of said steps of performing migrations are for correcting representations of the position and angle of dipping reflectors in the survey area.
Claim 10
Dependent Claim
17 words
The method of claim 1, wherein said plurality of shot lines are not parallel to one another.
Claim 11
Dependent Claim
27 words
The method of claim 1, wherein said step of creating a representation comprises: associating an angle value and an intercept value with each of said shot lines.
Claim 12
Dependent Claim
21 words
The method of claim 1, wherein said step of creating a representation is prior to said step of performing two-dimensional migrations.
Claim 13
Independent Claim
160 words
A method for producing a migrated three-dimensional seismic image from two-dimensional seismic data from a plurality of shot lines in a seismic survey area, comprising the steps of: creating a representation of the survey area according to the position and the orientation of each of the shot lines relative to one another; for the portion of the seismic data corresponding to each shot line, performing a two-dimensional migration to produce a plurality of migrated shot lines; selecting a plurality of image points in said representation; for each image point, performing the following substeps: for each migrated shot line, selecting a migrated trace therein in such a manner that a line drawn in said representation from the selected image point to the selected trace is perpendicular to the migrated shot line; performing a two-dimensional migration of each selected trace with respect to the image point; and summing the migrated selected traces to form an output trace corresponding to the image point.
Claim 14
Independent Claim
160 words
A method for producing a migrated three-dimensional seismic image from two-dimensional seismic data from a plurality of shot lines in a seismic survey area, comprising the steps of: creating a representation of the survey area according to the position and the orientation of each of the shot lines relative to one another; for the portion of the seismic data corresponding to each shot line, performing a two-dimensional migration to produce a plurality of migrated shot lines; selecting a plurality of image points in said representation; for each image point, performing the following substeps: for each migrated shot line, selecting a migrated trace therein in such a manner that a line drawn in said representation from the selected image point to the selected trace is perpendicular to the migrated shot line; performing a two-dimensional migration of each selected trace with respect to the image point; and summing the migrated selected traces to form an output trace corresponding to the image point.
Claim 15
Dependent Claim
18 words
The method of claim 12, wherein each of said steps of performing two-dimensional migrations comprise performing Kirchoff migrations.
Claim 16
Dependent Claim
31 words
The method of claim 12, wherein each of said steps of performing two-dimensional migrations are for correcting representations of the position and angle of sub-surface dipping reflectors in the survey area.
Claim 17
Dependent Claim
17 words
The method of claim 12, wherein said plurality of shot lines are not parallel to one another.
Claim 18
Dependent Claim
27 words
The method of claim 12, wherein said step of creating a representation comprises: associating an angle value and an intercept value with each of said shot lines.
Claim 19
Dependent Claim
30 words
The method of claim 12, wherein said step of creating a representation is performed prior to said step of performing two-dimensional migrations to produce a plurality of migrated shot lines.
Claim 20
Dependent Claim
187 words
A computer for creating three-dimensional representations of stored two-dimensional seismic data, taken from a plurality of shot lines in a survey area, said computer programmed to perform the steps of: representing said seismic data in a representation which corresponds to the spatial relationship of the shot lines in the survey area; for each portion of said seismic data corresponding to each of said shot lines, performing a two-dimensional migration thereof to generate migrated seismic data in the form of a plurality of migrated traces corresponding to each shot line; selecting a plurality of image points in said representation, said image points corresponding to points in said survey area; for each of said selected image points, performing the substeps of: selecting the migrated trace for each of said plurality of migrated shot lines that is closest to the image point in said representation; and for each selected migrated trace, performing a migration with respect to the image point; and storing, for each of said image points, the results of said migrations of said selected migrated traces performed therewith, to form a migrated three-dimensional image of the survey area.
Claim 21
Dependent Claim
187 words
A computer for creating three-dimensional representations of stored two-dimensional seismic data, taken from a plurality of shot lines in a survey area, said computer programmed to perform the steps of: representing said seismic data in a representation which corresponds to the spatial relationship of the shot lines in the survey area; for each portion of said seismic data corresponding to each of said shot lines, performing a two-dimensional migration thereof to generate migrated seismic data in the form of a plurality of migrated traces corresponding to each shot line; selecting a plurality of image points in said representation, said image points corresponding to points in said survey area; for each of said selected image points, performing the substeps of: selecting the migrated trace for each of said plurality of migrated shot lines that is closest to the image point in said representation; and for each selected migrated trace, performing a migration with respect to the image point; and storing, for each of said image points, the results of said migrations of said selected migrated traces performed therewith, to form a migrated three-dimensional image of the survey area.
Claim 22
Dependent Claim
20 words
The computer of claim 18, programmed to perform the additional step of displaying the three-dimensional image of the survey area.
Claim 23
Dependent Claim
26 words
The computer of claim 18, wherein the stored seismic data is taken from shot lines which are not parallel to one another in the survey area.