US3811111A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of exploring a medium by transmitting energy emitted in the form of separate impulses and its application to seismic prospecting
Assignee: NAT DES PETROLES SA
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Filing: 1972-06-12
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Granted: 1974-05-14
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Expires: 1992-06-12
Abstract
Abstract This invention concerns a method of exploring a medium by transmitting energy emitted in the form of separate impulses, and its application to seismic prospecting. It is characterized by the fact that the long signal is emitted by a number of sources off-set laterally from one another and from the receiver, the moments of emission by each source being such that when the sequence of moments of emission by all the sources are intercorrelated with the sequence of moments of emission by any one source, a function is obtained, for a duration equal to the longest time taken by waves to travel both ways through the medium, the ratio of the amplitude of the maximum peak of this function to the amplitude of the secondary residues being approximately the same as the corresponding ratio for the autocorrelation function of the moments of emission of this same single source.
Inventors
- 👤 M Barbier
- 👤 P Staron
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 07:10
CPC Classifications
G; G01; G01V; G01V1/00; G01V1/16; G01V1/20
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
186 words
A method of seismic prospecting of a medium which comprises the steps of: transmitting into said medium from a plurality of emission sources laterally off-set from one another a long signal consisting of a series of separate energy impulses of substantially uniform amplitude, the series of impulses being such that the autocorrelation function of the series of impulses emitted from each source of said plurality of sources presents correlation residues lower than a given fraction of the maximum amplitude of the autocorrelation function and the intercorrelation function of the series of impulses from all of said emission sources with the series of impulses from any one source presents secondary residues the amplitude of which is approximately the same given fraction of the maximum amplitude of the intercorrelation function, receiving by means of a receiver system and recording said energy signals after reflection from reflectors in said medium, said receiving system being laterally off-set from at least one of said emission sources, and cross-correlating the recorded signals with the lOng signal emitted by each source for determining the travel time of the reflected signals in said medium.
Claim 2
Independent Claim
186 words
A method of seismic prospecting of a medium which comprises the steps of: transmitting into said medium from a plurality of emission sources laterally off-set from one another a long signal consisting of a series of separate energy impulses of substantially uniform amplitude, the series of impulses being such that the autocorrelation function of the series of impulses emitted from each source of said plurality of sources presents correlation residues lower than a given fraction of the maximum amplitude of the autocorrelation function and the intercorrelation function of the series of impulses from all of said emission sources with the series of impulses from any one source presents secondary residues the amplitude of which is approximately the same given fraction of the maximum amplitude of the intercorrelation function, receiving by means of a receiver system and recording said energy signals after reflection from reflectors in said medium, said receiving system being laterally off-set from at least one of said emission sources, and cross-correlating the recorded signals with the lOng signal emitted by each source for determining the travel time of the reflected signals in said medium.
Claim 3
Dependent Claim
37 words
An improved method as defined in claim 1, in which the sources of emission are aligned at right angles to the direction of the receiver system, with one source on the same axis as said receiver system.
Claim 4
Dependent Claim
31 words
An improved method as defined in claim 2, in which the lateral distance between two consecutive sources is the same as the distance between the receiver system and said one source.
Claim 5
Dependent Claim
34 words
An improved method as defined in claim 1, in which several receiver systems are used, and the energy impulses emitted by each source and reflected by different reflectors are recorded by each receiver system.
Claim 6
Dependent Claim
27 words
An improved method as defined in claim 1, in which the sources emit impulses cyclically one after another, each source emitting a single impulse in each cycle.
Claim 7
Dependent Claim
53 words
An improved method as defined in claim 5, in which the intervals of time between two consecutive moments of emission in the sequence of moments of emission by all the sources are multiples of one basic time unit, plus a fixed time unit, the sequence of multipliers being a series of random numbers.
References Cited (Backward Citations)
US2989726A
Cited
US3332511A
Cited
US3622970A
Cited
US3736554A
Cited
US3698009A
Cited
US3680040A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-05-13 | 1977-11-12 | 1978-05-14 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-05-13 | 1981-11-12 | 1982-05-14 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-05-13 | 1985-11-12 | 1986-05-14 | $7700.00 | Window Closed / Lapsed |