US4841444A
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Method for continuous estimation by non-linear signal matching of seismic traces
Assignee: ConocoPhillips Co
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Filing: 1988-09-30
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Granted: 1989-06-20
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Expires: 2008-09-30
Abstract
Abstract A method for continuous velocity estimation of seismic data uses non-linear signal matching. Common depth point trace data is examined at selected offsets and non-linear signal matching is performed to derive moveout information from which the RMS and interval velocities may be further estimated. Non-linear signal matching for selected offsets of each CDP trace gather functions to derive characteristic match curve data at selected depths or travel time intervals. The match curve data inherently contains moveout information that relates to energy velocities for the particular trace position. Derived velocity data for selected time depths may then be output across a line of survey.
Inventors
- 👤 Chittibabu Chittineni
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 01:35
CPC Classifications
G; G01; G01V; G01V1/00; G01V1/28; G01V1/34; G01V1/30; G01V1/303
Claims Analysis
Total Claims: 16
Claim 1
Independent Claim
169 words
A method for determining a continuous velocity for the propagation of acoustic seismic pulses through subsurface formations in a system where acoustic pluses are generated by a seismic source transmitted into the earth, reflected back by interfaces, detected by seismic pulse receivers and converted to electrical signals representing a series of sequentially detected acoustic pulses, said method including the steps of: receiving signals representing detected acoustic pulses; selecting signals representing acoustic pulses having a common reflection midpoint between a seismic source and a seismic pulse receiver; determining a beginning point, intermediate points and an end point for each selected signal; estimating non-linear signal match curves for said selected signals; calculating derivatives of the inverse of the square of the root mean square velocity of the acoustic pulses represented by each said selected signal; computing root mean square velocities of the acoustic pulses by integrating said derivatives; estimating interval velocities for the acoustic pulses between interfaces; establishing a continuous velocity for the acoustic pulses; and displaying said estimated interval velocities.
Claim 2
Independent Claim
169 words
A method for determining a continuous velocity for the propagation of acoustic seismic pulses through subsurface formations in a system where acoustic pluses are generated by a seismic source transmitted into the earth, reflected back by interfaces, detected by seismic pulse receivers and converted to electrical signals representing a series of sequentially detected acoustic pulses, said method including the steps of: receiving signals representing detected acoustic pulses; selecting signals representing acoustic pulses having a common reflection midpoint between a seismic source and a seismic pulse receiver; determining a beginning point, intermediate points and an end point for each selected signal; estimating non-linear signal match curves for said selected signals; calculating derivatives of the inverse of the square of the root mean square velocity of the acoustic pulses represented by each said selected signal; computing root mean square velocities of the acoustic pulses by integrating said derivatives; estimating interval velocities for the acoustic pulses between interfaces; establishing a continuous velocity for the acoustic pulses; and displaying said estimated interval velocities.
Claim 3
Dependent Claim
37 words
The method according to claim 1 wherein said estimating non-linear signal match curves step includes the steps of: non-linearly matching signals having common reflection midpoints at selected offset valves; and computing the slope of each match curve.
Claim 4
Dependent Claim
91 words
The method according to claim 1 wherein said computing root mean square velocities step includes the steps of: determining slopes for said signal match curves between predetermined points of said signal matching estimate; forming a coefficient matrix and a vector representing changes of the square of the inverse of the root mean square velocity with respect to time; calculating a matrix representing the correlation of the derivative of said square of the inverse of said root mean square velocity; and computing a coefficient vector representing weight values for a constraining parameter.
Claim 5
Dependent Claim
17 words
The method according to claim 1 wherein said computing step includes adding constraints of known velocity information.
Claim 6
Dependent Claim
20 words
A method as set forth in claim 1 wherein: said root mean square velocities are root mean square seismic velocities.
Claim 7
Dependent Claim
27 words
A method as set forth in claim 1 which further includes: processing the root mean square velocities over a predetermined interval to determine respective interval velocity estimates.
Claim 8
Dependent Claim
53 words
A method as set forth in claim 1 wherein said step of computing root mean square velocities includes: determining successive slopes for the signal match curve over a time interval; and relating said successive slopes to estimate the successive derivative values for the inverse of the square of the root mean square velocities.
Claim 9
Dependent Claim
43 words
A method as set forth in claim 1 wherein said step of computing root mean square velocities includes: applying selected constraints to the estimated velocities at each of the end and intermediate check points thereby to minimize the estimation errors in signal matching.
Claim 10
Dependent Claim
61 words
A method as set forth in claim 1 which is further characterized in that: the steps of receiving, selecting, determining, estimating and computing are carried out for a succession of signals representing common depth point trace data gathers that extend over a selected line of a survey; and interval velocities estimated are for the selected interval across the line of survey.
Claim 11
Dependent Claim
29 words
A method as set forth in claim 9 wherein: said estimated interval velocities are presented in differential color display of the time interval extending across the line of survey.
Claim 12
Dependent Claim
28 words
A method as set forth in claim 10 wherein: said differential color display is presented in time coincident overlay with a selected display mode of seismic section data.
Claim 13
Dependent Claim
48 words
A method as set forth in claim 9 which further includes: processing the root mean square velocity of the acoustic pulses over said interval to determine respective interval velocity estimates; and outputting signals indicating interval velocity estimates along time intervals of each of said successive trace data gathers.
Claim 14
Dependent Claim
31 words
A method as set forth in claim 12 wherein: said signals indicating interval velocity estimates is presented in differential color display of the time interval extending across the line of survey.
Claim 15
Dependent Claim
28 words
A method as set forth in claim 13 wherein: said differential color display is presented in time coincident overlay with a selected display mode of seismic section data.
Claim 16
Dependent Claim
23 words
A method as set forth in claim 1 wherein: said estimated interval velocities are presented in differential color display of the time interval.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1992-06-19 | 1992-12-19 | 1993-06-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-06-19 | 1996-12-19 | 1997-06-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2000-06-19 | 2000-12-19 | 2001-06-20 | $7700.00 | Window Closed / Lapsed |