Communications – electrical: acoustic wave systems and devices – Signal transducers – Receivers
Patent
1992-04-27
1993-10-12
Lobo, Ian J.
Communications, electrical: acoustic wave systems and devices
Signal transducers
Receivers
367188, 367 15, 181122, 181401, G01V 116, G01V 138
Patent
active
052532232
DESCRIPTION:
BRIEF SUMMARY
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a device and a method for use on a seabed to collect and record signals during the execution of marine seismic off-shore explorations. Basically, the invention concerns seismic exploration of the substratum offshore, where pressure and shear waves from the substratum are measured in response to the releasing of pressure and/or shear wave energy.
2. Description of the Related Art
Marine seismic exploration is usually carried out by a seismic cable provided with several hydrophones being towed at a certain depth. Pressure waves are released in the vicinity of the cable in several ways. This usually takes place by means of air guns. The pressure wave energy travels downwards through the substratum, but parts of the pressure waves are reflected from areas where there are acoustic impedance features in the substratum. The hydrophones record the reflected pressure waves in the water and transform this information into electric signals which are received and processed on the seismic ship which tows the cable. Using this method, only reflected and/or converted shear to pressure wave energy is recorded. However, it is known that down in the formation both pressure waves and shear waves will be reflected. The shear waves do not travel in water and cannot therefore be detected by a hydrophone cable. Moreover, with today's conventional hydrophone technology, it is not possible to detect the directions of the measured signals, and this severely complicates the possibilities of three-dimensional data collection.
SUMMARY OF THE INVENTION
The objective of the invention is to provide a new and improved device and method for the recording of three-dimensional pressure and shear waves which travel in the substratum.
The above objective is met by providing a device including instruments for use on seabed for the collection and recording of first signals during off-shore seismic exploration. The device includes first, second and third geophones arranged in x, y and z directions, respectively, which produce geophone signals; an electronic angle gauge; a compass; a top portion having means for allowing said device to be handled; an intermediate portion being substantially cylindrical in shape and having a first end being connected to the top portion; a pointed end, connected to a second end of the intermediate portion, which houses the geophones, the electronic angle gauge and the compass; a hydrophone for recording pressure waves which is disposed proximate to the top portion; a battery; a processor which processes the geophone signal; a memory unit which stores information; an acoustic communications system for receiving and transmitting second and third signals; an optical reader which reads collected measurements; and a power supply which supplied power to the processor and the memory unit. In addition, the battery, the processor, the memory unit, the communication system, the optical reader, the power supply, and the hydrophone are disposed in the intermediate portion.
BRIEF DESCRIPTION OF DRAWINGS
The invention will be more closely described in the following, with reference to the accompanying drawings where:
FIG. 1 shows a schematical drawing of a geopole according to the invention.
FIG. 2A illustrates a sub sea vessel after the laying out of poles on the sea-bed, seen from above.
FIG. 2B illustrates execution of a seismic exploration.
FIG. 2C illustrates a magazine for poles according to the invention.
FIG. 2D shows a geopole.
FIG. 2E shows a submarine vessel.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
The device shown in FIG. 1 has a pole-like shape and comprises a cylindrical portion 1, a lower conically shaped or pointed end 2 and an upper portion 3. The upper portion 3 is compatible to equipment for inserting the pole down into, or pulling it out of the sea bed. In the shown embodiment, the upper portion is designed with a narrowing part 4 and an upper flange 5. This design is advantageous in that the flange 5 can b
REFERENCES:
patent: 3987404 (1976-10-01), Woodruff
patent: 4134097 (1979-01-01), Cowles
patent: 4163206 (1979-07-01), Hall, Jr.
patent: 4323988 (1982-04-01), Will et al.
patent: 4405036 (1983-09-01), Wener et al.
patent: 4516227 (1985-05-01), Wener et al.
patent: 4870625 (1989-09-01), Young et al.
patent: 5007031 (1991-04-01), Erich, Jr.
Berg Eivind
Svenning Bjornar
Den Norske Stats Oljeselskap A.S.
Lobo Ian J.
LandOfFree
Seismic device does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Seismic device, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Seismic device will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-1911376