Eccentric Particle Motion Sensors for Torque Noise Suppression

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Solution Overview

Problem

Seismic streamers in marine surveys face significant challenges in suppressing torque noise, which contaminates seismic data and complicates the identification of hydrocarbon deposits due to the eccentric positioning of particle motion sensors, leading to rotation-induced noise that is difficult to discriminate from the desired seismic signal.

Innovation Solution

The solution involves eccentrically disposing particle motion sensors at varying angles along the seismic streamer to modulate the wavenumber of torque noise, either by using dual sensors with opposite phasing at each location or varying the phasing scheme along the streamer length, effectively canceling out or moving torque noise out of the signal cone in frequency-wavenumber space.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If particle motion sensors are eccentrically disposed on a seismic streamer, then the streamer can be towed behind a survey vessel, but torque noise is generated that contaminates seismic data

Engineering Contradiction:

ImproveStreamer towing capabilityVSAvoidTorque noise contamination

Core Design Contradiction:

Ease of operationVSObject-affected harmful factors

Solution Approach 1:

The patent converts the harmful torque noise into a beneficial effect by using the noise itself as a reference signal. Dual sensors are positioned to receive the same torque noise, and by subtracting the noise from one sensor's measurement from the other sensor's measurement, the noise is canceled out, leaving only the desired seismic signal.

Inventive Principle:

Principle #22Blessing in disguise (Convert harm into benefit)

Solution Approach 2:

The patent introduces an intermediary approach by using a second sensor as a mediator to capture the torque noise. This second sensor acts as a reference that allows the system to identify and remove the noise from the primary sensor's measurement through signal processing.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Object-affected harmful factors

If dual sensors with opposite phasing are used to cancel torque noise, then noise suppression is achieved, but device complexity increases

Engineering Contradiction:

ImproveTorque noise suppressionVSAvoidSensor configuration complexity

Core Design Contradiction:

Object-affected harmful factorsVSDevice complexity

Solution Approach 1:

The patent merges the functions of multiple sensors into a unified measurement system. By combining the measurements from dual sensors with opposite phasing and using signal processing to cancel noise, the system achieves noise suppression while maintaining a relatively simple overall structure.

Inventive Principle:

Principle #5Merging (Combining)

Data Source

PatentUS9513393B2System and technique to suppress the acquisition of torque noise on a multi-component streamer

Publication Date: 2016.12.06 WESTERNGECO LLC

AI summary

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.