Dual axis geophones for pressure/velocity sensing streamers forming a triple component streamer
View Patent ↗A seismic streamer includes a sensor comprises an axially oriented body including a plurality of axially oriented channels arranged in opposing pairs; a plurality of hydrophones arranged in opposing pairs in the channels; a pair of orthogonally oriented acoustic particle motion sensors; and a tilt sensor adjacent or associated with the particle motion sensors. The streamer has a plurality of hydrophones, as previously described, aligned with a plurality of accelerometers which detect movement of the streamer in the horizontal and vertical directions, all coupled with a tilt sensor, so that the marine seismic system can detect whether a detected seismic signal is a reflection from a geologic structure beneath the streamer or a downward traveling reflection from the air/seawater interface.
1. A carrier configured to be provided in a streamer for acoustic marine data collection, the carrier comprising:
a single body having plural channels;
a first hydrophone provided in a first channel of the plural channels;
a first accelerometer provided in a second channel of the plural channels;
a second accelerometer provided in the first channel, wherein the first accelerometer is offset in a radial direction from the second accelerometer; and
a tilt sensor located in one of the first and second channels,
wherein the tilt sensor is configured to determine an angle of tilt of the carrier about a gravity direction, and
wherein the second channel has no other hydrophone or accelerometer sensor.
2. The carrier of claim 1 , wherein the offset is about 90°.
3. The carrier of claim 1 , further comprising:
a second hydrophone provided in a channel opposite the first channel.
4. The carrier of claim 1 , further comprising:
a third accelerometer provided in a channel opposite the second channel; and
a fourth accelerometer provided in a channel opposite the first channel.
5. The carrier of claim 1 , further comprising:
a buoyant material; and
a jacket enclosing the body, the first accelerometer, the second accelerometer, the first hydrophone, the tilt sensor, and the buoyant material.
6. The carrier of claim 1 , further comprising:
an internal housing extending axially through the body and configured to allow a cable to axially pass through the entire body.
7. A carrier configured to be provided in a streamer for acoustic marine data collection, the carrier comprising:
a single body having first and second pairs of opposite channels;
a first accelerometer provided at a first radial position in the first pair of opposite channels;
a second accelerometer provided at a second radial position in the second pair of opposite channels; and
a tilt sensor located in one of the first and second pairs of opposite channels and configured to determine a tilt angle of the carrier about a gravity direction,
wherein the second pair of opposite channels has no hydrophone sensor.
8. The carrier of claim 7 , wherein there is a 90° difference between the first radial position and the second radial position.
9. The carrier of claim 7 , further comprising:
at least one hydrophone located in the first pair of opposite channels.
10. The carrier of claim 7 , further comprising:
a third accelerometer provided opposite the first accelerometer; and
a fourth accelerometer provided opposite the second accelerometer.
11. The carrier of claim 7 , further comprising:
a buoyant material; and
a jacket enclosing the body, the first accelerometer, the second accelerometer, the tilt sensor, and the buoyant material.
12. The carrier of claim 7 , further comprising:
an internal housing extending axially through the body and configured to allow a cable to axially pass through the entire body.
13. A marine streamer configured to be towed by a vessel under-water for collecting seismic data, the marine streamer comprising:
plural carriers provided along the streamer, a carrier having,
a single body having plural channels,
a first hydrophone provided in a first channel of the plural channels,
a first accelerometer provided in a second channel of the plural channels,
a second accelerometer provided in the first channel, wherein the first accelerometer is offset in a radial direction from the second accelerometer, and
a tilt sensor attached to the single body; and
a field digitizing unit configured to receive analog signals from the first hydrophone and generate a corresponding digital signal,
wherein the tilt sensor is configured to determine a tilt angle of the carrier about a gravity direction, and
wherein the second channel has no other hydrophone or accelerometer sensor.
14. A marine streamer configured to be towed under-water by a vessel for collecting seismic data, the marine streamer comprising:
plural carriers provided along the streamer, a carrier having,
a single body having first and second pairs of opposite channels,
a first accelerometer and a first hydrophone provided at a first radial position in the first pair of opposite channels,
a second accelerometer provided at a second radial position in the second pair of opposite channels, and
a tilt sensor located in one of the first and second pairs of opposite channels and configured to determine an angle of tilt of the carrier about a gravity direction; and
a field digitizing unit configured to receive analog signals from the first hydrophone and generate a corresponding digital signal,
wherein the tilt sensor is configured to determine a tilt angle of the carrier about a gravity direction, and
wherein the second pair of opposite channels has no hydrophone sensor.