US3622970A
Expired / Lapsed
US
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Method of seismic prospecting
Assignee: Societe Nationale des Petroles dAquitaine SA
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Filing: 1969-06-19
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Granted: 1971-11-23
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Expires: 1989-06-19
Abstract
Abstract A method of seismic prospecting comprises transmitting into the ground a signal containing a series of discrete energy impulses of the same sign and constant amplitude in which the number of and intervals of time between the pulses are such that when the received signals are intercorrelated with a function of the transmitted signal to determine the travel time of the reflected waves the intercorrelation function of the transmitter signal has correlation residues, the amplitudes of which are less than a given fraction of the maximum amplitude of said intercorrelation function.
Inventors
- 👤 Leon Sayous
- 👤 Maurice Barbier
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 06:40
CPC Classifications
G; G01; G01V; G01V1/00; G01V1/003; G01V1/005
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
158 words
Seismic prospecting by correlated waves comprising the steps of: transmitting into the ground a long signal, constituted by a series of distinct elementary energy pulses of the same sign and of substantially constant energy, and separated by unequal and nonrepetitive short intervals of time, the series of pulses being such that the autocorrelation function of the signal transmitted presents harmonic contents of correlation whose amplitude is lower than a given fraction of the maximum amplitude of this function; detecting and recording, successively, after reflection from reflectors, each distinct energy signal; producing a function of the time whicH takes the value 1 at each instant when an energy pulse is transmitted and remains zero the rest of the time; intercorrelating the signals received with said function of the time for the purpose of determining the travel time of the signals reflected from reflectors; and measuring the travel times from the maximum of the autocorrelation function of the transmission function.
Claim 2
Dependent Claim
158 words
Seismic prospecting by correlated waves comprising the steps of: transmitting into the ground a long signal, constituted by a series of distinct elementary energy pulses of the same sign and of substantially constant energy, and separated by unequal and nonrepetitive short intervals of time, the series of pulses being such that the autocorrelation function of the signal transmitted presents harmonic contents of correlation whose amplitude is lower than a given fraction of the maximum amplitude of this function; detecting and recording, successively, after reflection from reflectors, each distinct energy signal; producing a function of the time whicH takes the value 1 at each instant when an energy pulse is transmitted and remains zero the rest of the time; intercorrelating the signals received with said function of the time for the purpose of determining the travel time of the signals reflected from reflectors; and measuring the travel times from the maximum of the autocorrelation function of the transmission function.
Claim 3
Dependent Claim
38 words
Seismic prospecting using correlated waves according to claim 1, wherein the series of energy pulses of substantially constant amplitude is governed by a law of random appearance of these pulses, said pulses being produced by a spark generator.
Claim 4
Dependent Claim
47 words
Seismic prospecting by correlated waves according to claim 2, wherein the intervals of time separating the appearance of two successive pulses of a series are multiples of the same base time to within about a fixed time, the series of multipliers being a random series of numbers.
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) | 1974-11-22 | 1975-05-24 | 1975-11-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-11-22 | 1979-05-24 | 1979-11-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-11-22 | 1983-05-24 | 1983-11-23 | $7700.00 | Window Closed / Lapsed |