Abstract:
A section of a streamer for acoustic marine data collection, the section comprising a carrier for accommodating seismic sensors, wherein the carrier includes, a single body, a first particle motion sensor located on the single body, and a second particle motion sensor being located on the single body, with a 90° angular offset, about a longitudinal axis of the carrier, relative to the first particle motion sensor; and a tilt sensor coupled to the carrier and having a known direction relative to the first and second particle motion sensors so that the tilt sensor determines an angle of tilt of the carrier about a vertical, wherein the first and second particle motion sensors measure a motion related parameter and not a pressure.
Abstract:
A restrictor device is used on a cable to protect the cable from excessive bending. The restrictor device includes two or more restrictor members having a helix shape extending along a longitudinal axis X; and fasteners that connect the two or more restrictor members to each other to form the restrictor device. At least one property of the two or more restrictor members is selected such that a bending portion of the restrictor device moves along the restrictor device when a magnitude of a force applied to the restrictor device changes.
Abstract:
Method and apparatus for mitigating vibrations in a device towed in water. The apparatus includes one or more tuned elastic sections having a complex spring rate and adapted to attenuate vibrations in a specified frequency range; and a head end coupler adapted to couple the apparatus for vibration mitigation to a component of an electro-mechanical cable or a tow assembly. One of the one or more tuned elastic sections is coupled to the head end coupler with a high impedance material interface.
Abstract:
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.
Abstract:
A seismic source for generating seismic waves under water includes an operating head having an operating chamber, a cushion chamber, and discharge ports, a firing chamber attached to the operating head, the firing chamber configured to hold compressed air to be discharged through the discharge ports, and a shuttle assembly having a shaft located within the operating head and configured to prevent the compressed air in the firing chamber to enter the discharge ports when in a close state, and to allow the compressed air in the firing chamber to be discharged through the discharge ports when in an open state. The shaft of the shuttle assembly which extends in both the operating chamber and the cushion chamber, has a channel having a varying depth.
Abstract:
A seismic source having two or more operating heads with a firing chamber pressure vessel of compressed air for generating seismic oscillations at low and ultra-low frequencies (ULF) for marine seismic exploration. The multi-headed sound source increases low frequency signal in ranges from below 1 Hz to around 7 Hz to provide greater penetration of the seismic signal through complex overburden such as salt or basalt, improve velocity model building with methods such as Full Wave Inversion, improve the ability to build blocky reservoir models, and improve resolution by reducing side lobes.
Abstract:
A seismic source for generating seismic waves under water includes an operating head having an operating chamber, a cushion chamber, and discharge ports, a firing chamber attached to the operating head, the firing chamber configured to hold compressed air to be discharged through the discharge ports, and a shuttle assembly having a shaft located within the operating head and configured to prevent the compressed air in the firing chamber to enter the discharge ports when in a close state, and to allow the compressed air in the firing chamber to be discharged through the discharge ports when in an open state. The shaft of the shuttle assembly which extends in both the operating chamber and the cushion chamber, has a channel having a varying depth.
Abstract:
A section of a streamer for acoustic marine data collection, the section having a carrier for accommodating seismic sensors, wherein the carrier includes, a single body, a first particle motion sensor located on the single body, and a second particle motion sensor being located on the single body, with a 90° angular offset, about a longitudinal axis of the carrier, relative to the first particle motion sensor; and a tilt sensor coupled to the carrier and having a known direction relative to the first and second particle motion sensors so that the tilt sensor determines an angle of tilt of the carrier about a vertical. The first and second particle motion sensors measure a motion related parameter and not a pressure.
Abstract:
There is a testing device for testing a sensor. The testing device includes a rotating mechanism; a first rotating plate connected to the rotating mechanism so that the first rotating plate rotates around an orbital axis (Z1); a second plate rotatably attached to the first rotating plate at a rotating point, the second plate having a rotational axis (Z2) offset from the orbital axis (Z1) by a predetermined distance R; and a gripping mechanism attached to the second plate and configured to receive and fix the sensor relative to the second plate. The second plate follows a circular trajectory with constant attitude around the orbital axis (Z1).
Abstract:
A method for electrically setting a gap for a piezoelectric pressure sensor. The method includes positioning a piezoelectric flex element on a tray; attaching a voltage source to the piezoelectric flex element of a piezoelectric pressure sensor; applying a voltage from the voltage source to the piezoelectric flex element; curing an adhesive between the piezoelectric flex element and the tray while the piezoelectric flex element is deflected by the voltage; and stopping the voltage from the voltage source to the piezoelectric flex element when the adhesive has been cured.