US4008459A
Expired / Lapsed
US
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Method of seismic surveying for stratigraphic traps
Assignee: Texaco Inc
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Filing: 1975-07-18
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Granted: 1977-02-15
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Expires: 1995-07-18
Abstract
Abstract A method for recognizing the presence of and defining the location of a subsurface stratigraphic trap by seismic exploration is disclosed wherein a common depth point seismic source-detector spread is in effect moved along a prospecting line along the surface of the earth. The apparent stacking velocity to a plurality of selected subsurface reflectors is obtained at each common depth point location and is plotted as a function of horizontal distance. Differentials in the stacking velocity plots are compared to provide an estimate of the horizontal location along the survey line of subsurface stratigraphic traps. Additionally, a technique for determining the approximate depth of such traps is disclosed.
Inventors
- 👤 Hugh O. Walker, Jr.
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 01:31
CPC Classifications
G; G01; G01V; G01V1/00; G01V1/003
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
280 words
A method of seismic prospecting for stratigraphic traps of expected horizontal extent in subterranean earth formations comprising the steps of: a. arranging a seismic source detector spread comprising a plurality of seismic energy sources and a plurality of seismic detectors having a horizontal extent approximately at least twice the expected horizontal extent of any subsurface feature being prospected for at a first source detector spread location along a line traversing a subterranean region to be prospected; b. imparting from seismic energy sources at said first spread location, acoustic energy which travels generally downwardly and outwardly from said source into the subterranean region to be prospected; c. recording as a function of time signals representative of the amplitudes of reflected seismic energy at said detector locations in the spread; d. determining the apparent stacking velocity of seismic energy from a plurality of selected subsurface reflectors at each such impartation of seismic energy by said seismic energy sources; e. moving said source detector spread location a predetermined horizontal distance approximately 1/10 the expected horizontal extent of any subsurface feature being prospected for along said traversing line and repeating steps (b), (c) and (d) at each such new location; and f. comparing said apparent stacking velocities at each such source detector spread location, by graphically plotting the apparent stacking velocity at each source detector spread location to each selected subsurface reflector as a function of horizontal distance along said traversing line, to observe any differential present in said stacking velocities to each of said selected reflectors as a function of horizontal distance, thereby obtaining the approximately horizontal distance location along said traversing line of any stratigraphic traps in said subterranean region being prospected.
Claim 2
Independent Claim
280 words
A method of seismic prospecting for stratigraphic traps of expected horizontal extent in subterranean earth formations comprising the steps of: a. arranging a seismic source detector spread comprising a plurality of seismic energy sources and a plurality of seismic detectors having a horizontal extent approximately at least twice the expected horizontal extent of any subsurface feature being prospected for at a first source detector spread location along a line traversing a subterranean region to be prospected; b. imparting from seismic energy sources at said first spread location, acoustic energy which travels generally downwardly and outwardly from said source into the subterranean region to be prospected; c. recording as a function of time signals representative of the amplitudes of reflected seismic energy at said detector locations in the spread; d. determining the apparent stacking velocity of seismic energy from a plurality of selected subsurface reflectors at each such impartation of seismic energy by said seismic energy sources; e. moving said source detector spread location a predetermined horizontal distance approximately 1/10 the expected horizontal extent of any subsurface feature being prospected for along said traversing line and repeating steps (b), (c) and (d) at each such new location; and f. comparing said apparent stacking velocities at each such source detector spread location, by graphically plotting the apparent stacking velocity at each source detector spread location to each selected subsurface reflector as a function of horizontal distance along said traversing line, to observe any differential present in said stacking velocities to each of said selected reflectors as a function of horizontal distance, thereby obtaining the approximately horizontal distance location along said traversing line of any stratigraphic traps in said subterranean region being prospected.
Claim 3
Dependent Claim
49 words
The method of claim 1 and further including the step of obtaining the approximate depth of the stratigraphic trap traversed by said traversing line by multiplying the time of occurrence of any stacking velocity differential occurrence so observed by the apparent stacking velocity at the location of said differential.
Claim 4
Dependent Claim
40 words
The method of claim 1 wherein the step of imparting from each seismic energy source, acoustic energy which generally travels downwardly and outwardly from said source, is performed by so doing in a repetitive manner at each such source location.
Claim 5
Dependent Claim
23 words
The method of claim 1 wherein said seismic source detector spread comprises at least a six fold common depth point source detector array.
Claim 6
Dependent Claim
22 words
The method of claim 1 wherein said seismic source detector spread comprises at least a 12-fold common depth point source detector array.
Claim 7
Dependent Claim
22 words
The method of claim 1 wherein said seismic source detector spread comprises at least a 24-fold common depth point source detector array.
Claim 8
Dependent Claim
41 words
The method of claim 1 wherein the recording step is performed by digitally sampling the amplitude of reflected seismic energy at each detector as a function of time at a predetermined and recording said digital samples as a function of time.
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) | 1980-02-15 | 1980-08-16 | 1981-02-15 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-02-15 | 1984-08-16 | 1985-02-15 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-02-15 | 1988-08-16 | 1989-02-15 | $7700.00 | Window Closed / Lapsed |