초록 ▼

A method and device for seismic exploration of a subsea geologic formation by pickups set on the sea bottom and intermittently connectable to active data acquisition stations (11) brought nearby. Permanent passive reception stations (1) comprising a heavy pedestal provided with housings for seismic

A method and device for seismic exploration of a subsea geologic formation by pickups set on the sea bottom and intermittently connectable to active data acquisition stations (11) brought nearby. Permanent passive reception stations (1) comprising a heavy pedestal provided with housings for seismic pickups (geophones (6), hydrophone (7) which receive acoustic or seismic signals from the underlying formation are arranged at the bottom of the water body. When collection sessions for the signals received by the pickups are scheduled, mobile active acquisition stations (11) connected to permanent passive reception stations (1) are positioned at the bottom of the water body. The signals picked up are then recorded, for the time required to carry out at least one session of acquisition and recording of the acoustic or seismic signals received by the passive stations in response to the emission of seismic waves by one or more seismic sources. The mobile active acquisition stations (11) are thereafter recovered at the surface and the records acquired by each one are transferred to a central collection laboratory.

대표청구항 ▼

1. A method of seismic exploration of an underwater geologic formation comprising:laying, at a bottom of a water body, at spaced apart locations, at least one passive reception station and locating respective positions of each passive reception station in relation to known positions at a water surfa

1. A method of seismic exploration of an underwater geologic formation comprising:laying, at a bottom of a water body, at spaced apart locations, at least one passive reception station and locating respective positions of each passive reception station in relation to known positions at a water surface, each passive reception station including pickups coupled to the geologic formation for receiving geologic formation; laying, at the bottom of the water body, in a vicinity of the at least one passive reception stations, at least one active acquisition station which acquires and records signals received by the pickups of the at least one passive reception station in a vicinity thereof coupled thereto and with the geologic formation, for a time required to carry out at least one acquisition and recording session of the signals; and transferring data accumulated by each active acquisition station to a central collection laboratory. 2. A method as claimed in claim 1, wherein the pickups comprise seismic pickups permanently installed in the passive stations and coupled to the geologic formation.3. A method as claimed in claim 2, wherein the pickups comprises instruments associated with the passive stations for measuring an orientation of the seismic pickups in relation to the geologic formation for a duration of at least one of the sessions.4. A method as claimed in claim 1, wherein the pickups are permanently connected to the at least one active station and intermittently coupled with the geologic formation by the passive stations for a duration of at least one of the sessions.5. A method as claimed in claim 4, wherein the pickups comprise seismic pickups and instruments for measuring an orientation of the seismic pickups in relation to the geologic formation.6. A method as claimed in claim 1, wherein each active station acquires and records signals received by pickups associated with multiple passive stations.7. A method as claimed in claim 2, wherein each active station acquires and records signals received by pickups associated with multiple passive stations.8. A method as claimed in claim 3, wherein each active station acquires and records signals received by pickups associated with multiple passive stations.9. A method as claimed in claim 4, wherein each active station acquires and records signals received by pickups associated with multiple passive stations.10. A method as claimed in claim 5, wherein each active station acquires and records signals received by pickups associated with multiple passive stations.11. A method as claimed in claim 1, wherein transfer of the data accumulated by each active acquisition station to the central collection laboratory is performed by recovery, at the water surface, of the active acquisition stations.12. A method as claimed in claim 2, wherein transfer of the data accumulated by each active acquisition station to the central collection laboratory is performed by recovery at the water surface, of the active acquisition stations.13. A method as claimed in claim 3, wherein transfer of the data accumulated by each active acquisition station to the central collection laboratory is performed by recovery at the water surface, of the active acquisition stations.14. A method as claimed in claim 4, wherein transfer of the data accumulated by each active acquisition station to the central collection laboratory is performed by recovery at the water surface, of the active acquisition stations.15. A method as claimed in claim 5, wherein transfer of the data accumulated by each active acquisition station to the central collection laboratory is performed by recovery at the water surface, of the active acquisition stations.16. A method as claimed in claim 6, wherein transfer of the data accumulated by each active acquisition station to the central collection laboratory is performed by recovery at the water surface, of the active acquisition stations.17. A method as claimed in claim 1, wherein transfer of the data accumulated by each active acquisition station to the central collection laboratory is performed by transmission cables.18. A method as claimed in claim 2, wherein transfer of the data accumulated by each active acquisition station to the central collection laboratory is performed by transmission cables.19. A method as claimed in claim 3, wherein transfer of the data accumulated by each active acquisition station to the central collection laboratory is performed by transmission cables.20. A method as claimed in claim 4, wherein transfer of the data accumulated by each active acquisition station to the central collection laboratory is performed by transmission cables.21. A method as claimed in claim 5, wherein transfer of the data accumulated by each active acquisition station to the central collection laboratory is performed by transmission cables.22. A method as claimed in claim 6, wherein transfer of the data accumulated by each active acquisition station to the central collection laboratory is performed by transmission cables.23. A method as claimed in claim 11, wherein transfer of the data accumulated by each active acquisition station to the central collection laboratory is performed by transmission cables.24. A method as claimed in claim 1, wherein laying and recovery of the passive and active acquisition stations is carried out by underwater vehicles.25. A system for providing seismic exploration of an underwater geologic formation, comprising at least one passive reception stations, each passive reception station comprising a pedestal for providing deployment on a bottom of a water body, a housing containing seismic pickups and an electrical connector connected by electric conductors to the seismic pickups, at least one active stations for connection to the at least one passive reception stations, each passive reception station comprising an electronic unit for acquiring and storing seismic signals received by the pickups, a power supply and at least one electrical connector for connecting, by a the electronic unit to the electrical connector associated with each passive reception station.26. A system as claimed in claim 25, comprising instruments which measure an orientation of the seismic pickups in relation to the geologic formation.27. A system for providing seismic exploration of an underwater geologic formation, comprising at least one passive reception station, each passive reception station comprising a pedestal for providing deployment on a bottom of the water body and to couple pickups with the geologic formation, at least one active station for connection to the at least one passive reception stations, for a time required to carry out at least one acquisition and recording session of seismic signals received by the pickups, each pickup comprising an electronic unit for acquiring and storing of the seismic signals and a power supply, the pedestal including a cavity for receiving the pickups, which are connected to the electronic unit by a cable.28. A system as claimed in claim 27, wherein the pickups are included in a removable module containing the pickups and instruments for measuring an orientation of the pickups in relation to the geologic formation, the module being disposed in a cavity of the pedestal coupled therewith with a predetermined angular orientation.29. A system as claimed in claim 28, wherein the pedestal comprises a hinged cover for contacting the removable module after the removable module has been set in the cavity.30. A system as claimed in claim 28, wherein the measuring instruments include a compass and an inclinometer.31. A system as claimed in claim 29, wherein the measuring instruments include a compass and an inclinometer.32. A system as claimed in claim 25, wherein each passive reception station comprises a pinger.33. A system as claimed in claim 27, wherein each passive reception station comprises a pinger.34. A system as claimed in claim 25, wherein each passive reception station comprises a means for contacting the geological formation.35. A system as claimed in claim 27, wherein each passive reception station comprises a means for contacting the geological formation.