Abstract:
A termination for an end of a braid formed as a flat closed loop of braided strands expandable to an annular cylinder having a selected wall thickness includes a sleeve having a selected internal diameter. Spacers are configured to be applied on the braid such that when in contact with each other form an annular cylinder having an external diameter selected to fit inside the sleeve. The spacers have a bevel at one longitudinal end. A substantially cylindrical insert has a bevel at one longitudinal end at substantially a same bevel angle as on the spacers. A diameter of the insert combined with twice the wall thickness of the braid is larger than an internal diameter the spacers. When axial tension is applied to the braid, the bevel on the insert with braid thereon laterally urges the spacers outward. The sleeve limits lateral outward movement of the spacers.
Abstract:
There is provided a solid seismic streamer cable for use in seismic surveying in marine environments. The streamer is characterised by a buffer layer 2 which is provided with a cut-out 50 and a sensor element arranged in the cut-out 50. There is also provided an associated hydrophone for integration into the seismic streamer cable. The hydrophone is characteristic in a split-element sensor base 10, 11 being suited for efficient mounting into the cut-outs 50 of the seismic cable. There is also provided an associated accelerometer for integration into the seismic streamer cable. The accelerometer is characteristic by a split-element sensor base 30, 35 for being efficiently arranged into the cut-outs 50 of the seismic cable. A method of producing a seismic streamer cable according to the invention incorporating a hydrophone or accelerometer according to the invention is also provided.
Abstract:
An apparatus includes a streamer cable having one or more seismic devices disposed within a polymer body and about a core. The polymer body includes a channel defined therein for receiving one or more wires connecting the seismic devices. The wires include slack for withstanding the tensional forces experienced by the streamer cable during deployment and operation. Associated methods are also described.
Abstract:
A technique includes distributing particle motion sensors along the length of a seismic streamer. Each particle motion sensor is eccentrically disposed at an associated angle about an axis of the seismic streamer with respect to a reference line that is common to the associated angles. The sensors are mounted to suppress torque noise in measurements that are acquired by the particle motion sensors. This mounting includes substantially varying the associated angles.
Abstract:
A marine seismic streamer includes at least one particle motion sensor array. The array includes a plurality of particle motion sensors disposed at spaced apart locations along the streamer. Outputs of the particle motion sensors are functionally coupled to form an array. A number of the particle motion sensors and a spacing between adjacent particle motion sensors are selected to attenuate noise in a selected mode of propagation and within a selected wavenumber range. The streamer includes means for weighting a signal output of each particle motion sensor in the at least one array. A signal weight applied to each sensor by the means for weighting is selected to optimize attenuation of the noise.
Abstract:
Method and retrievable vertical hydrophone cable for collecting seismic data underground. The retrievable vertical hydrophone cable includes an envelope having a first end at which a connector mechanism is provided to close the envelope; plural hydrophones distributed inside the envelope at predetermined positions; and a fluid provided inside the envelope and around the plural hydrophones. The envelope increases its volume when the fluid is pressurized through the connector mechanism.
Abstract:
A position sensing system including a flexible tether and at least one sensor at least partially embedded within a portion of the flexible tether is disclosed. The sensor may be adapted to detect a sensor position factor. The system also includes a communication device adapted to transmit the sensor position factor from the sensor, and a signal processor adapted to receive the sensor position factor. The signal processor is also adapted to calculate at least one of the shape or orientation of the flexible tether from the sensor position factor. The sensor position factor may be relative orientation, relative depth, relative pressure, presence of a magnetic field, presence of an electric field, acceleration, or relative rate of rotation. The system may also include a probe connected to the flexible tether, and the signal processor may calculate the orientation of the probe from the sensor position factor.
Abstract:
An anti-biofouling casing for a seismic streamer is described, the anti-biofouling casing including a polymer system having a hydrophobically-modified base polymer, the hydrophobically-modified base polymer including a base polymer having a backbone and a hydrophobically derivatized chain extender coupled to the backbone of the base polymer. The polymer system including between about 0.1% and 10% of the hydrophobically derivatized chain extender by weight. The anti-fouling casing including a hydrophobic surface that serves to prevent biofouling of the surface.
Abstract:
A disclosed data acquisition system includes one or more streamers having multiple spaced apart sensor units. At least one sensor unit includes at least one digital sensor employing a quantized feedback loop to produce a digital output signal. A data recording system collects and stores data from the sensor units. The quantized feedback loop may be adapted to exert a quantized force on the sensing element. A described method for acquiring data includes deploying at least one streamer having multiple spaced apart sensor units, where at least a portion of the sensor units include a digital sensor employing a quantized feedback loop to produce a digital output signal. A stimulus event is triggered. Data is received from the sensor units and stored.
Abstract:
A marine sensor cable comprises a jacket covering an exterior of the sensor cable, wherein the jacket comprises an outer portion containing biocide disposed in a co-extrusion process. A method for producing a marine sensor cable jacket comprises providing a co-extruder to construct a polyurethane jacket for a sensor cable with a first extruder constructing an inner portion of the jacket and a second extruder constructing an outer portion of the jacket; producing a mixture of thermo polyurethane and biocide; supplying thermo polyurethane to the first extruder; supplying the mixture of thermo polyurethane and biocide to the second extruder; and constructing the polyurethane jacket with the outer portion containing the biocide.