Abstract:
A system comprises a plurality of acoustic transmitters, mounted inside the streamers, adapted to transmit broadband signals having low cross-correlation between the signals of different transmitters; a plurality of acoustic receivers, mounted inside the streamers, adapted to receive the signals from the transmitters; at least one processor adapted to cross-correlate the signals received at the receivers with copies of transmitter signals to determine identities of the transmitters of the received signals and to determine travel times of the received signals; and a main processor adapted to convert the travel times to distances between the identified transmitters and the receivers and to determine relative positions of the streamers from the distances.
Abstract:
Signals of pressure sensors and particle motion sensors located in marine seismic streamers are combined to generate pressure sensor data and particle motion data with substantially the same broad bandwidth. The noisy low frequency part of the motion signals are calculated from the recorded pressure signals and merged with the non-noisy motion signals. The two broad bandwidth data sets can then be combined to calculate the full up- and down-going wavefields.
Abstract:
In one embodiment the invention comprises a particle velocity sensor that includes a housing with a geophone mounted in the housing. A fluid that substantially surrounds the geophone is included within the housing. The particle velocity sensor has an acoustic impedance within the range of about 750,000 Newton seconds per cubic meter (Ns/m3) to about 3,000,000 Newton seconds per cubic meter (Ns/m3). In another embodiment the invention comprises method of geophysical exploration in which a seismic signal is generated in a body of water and detected with a plurality of co-located particle velocity sensors and pressure gradient sensors positioned within a seismic cable. The output signal of either or both of the particle velocity sensors or the pressure gradient sensors is modified to substantially equalize the output signals from the particle velocity sensors and the pressure gradient sensors. The output signals from particle velocity sensors and pressure gradient sensors are then combined.
Abstract translation:在一个实施例中,本发明包括粒子速度传感器,其包括具有安装在壳体中的地震检波器的壳体。 基本上围绕地震检波器的流体包括在壳体内。 粒子速度传感器的声阻抗在每立方米约750,000牛顿秒(Ns / m 3)至约3,000,000牛顿秒/立方米(Ns / m 3 / SUP>)。 在另一个实施例中,本发明包括地球物理勘探方法,其中在水体中产生地震信号并且利用位于地震缆索内的多个共同定位的粒子速度传感器和压力梯度传感器进行检测。 粒子速度传感器或压力梯度传感器中的任一个或两者的输出信号被修改为基本上均衡来自粒子速度传感器和压力梯度传感器的输出信号。 然后组合来自粒子速度传感器和压力梯度传感器的输出信号。
Abstract:
A cable for towing marine devices is disclosed. The cable includes a strength member and at least one conduit associated with the strength member. The conduit has apertures therein at selected locations along the conduit. The apertures are adapted to conduct gas from a source into water in which the cable is disposed. Also disclosed is a method for improving the flow of a cable through water. The method includes releasing a gaseous bubble stream proximate an outer surface of said cable while the water is moving relative to the cable.