Forward looking systems and methods for positioning marine seismic equipment

Abstract

Systems and methods for positioning one or more spread elements of a marine seismic spread are described. One system comprises a seismic vessel-mounted acoustic Doppler current meter adapted to ascertain at least the horizontal component of the current velocity vector at a point ahead of the seismic vessel, and one or more controllers adapted to use the ascertained current velocity vector to control position of one or more seismic spread elements. It is emphasized that this abstract is provided to comply with the rules requiring an abstract, which will allow a searcher or other reader to quickly ascertain the subject matter of the technical disclosure. It is submitted with the understanding that it will not be used to interpret or limit the scope or meaning of the claims. 37 CFR 1.72(b).

Description

BACKGROUND OF THE INVENTION [0001] 1. Field of Invention [0002] The present invention relates to the field of marine seismic instrumentation and methods of using same. More specifically, the invention relates to systems and methods for positioning one or more spread elements of a marine seismic spread using information about the ocean current ahead of the towing vessel. [0003] 2. Related Art [0004] Marine seismic exploration investigates and maps the structure and character of subsurface geological formations underlying a body of water. For large survey areas, seismic vessels tow one or more seismic sources and multiple seismic streamer cables through the water. The entire system is typically referred to as a spread, and the elements making up the spread are referred to as spread elements. The seismic sources typically comprise compressed air guns for generating acoustic pulses in the water. The energy from these pulses propagates downwardly into the geological formations and is ref...

AI Technical Summary

Benefits of technology

[0020] Another method of the invention comprises estimating a vertical current profile at a predefined distance ahead of a spread element by using a vessel-mounted acoustic Doppler current meter mounted in a mounting and sampling current vertical component data at a defined rate, the mounting either fixing the meter in a single position relative to the vessel or enabling at least the acoustic beam transmitter or transmitters (sometimes referred to herein as “eyes”) to move relative to the vessel, the data sampling rate being at a frequency higher than a frequency of movement of meter or the beam transmitter. If a fixed position mounting is used, the meter will be useful when the vessel pitches. If the vessel is riding in a calm body of water, a pitching motion may be enforced. A mounting having a combination of features may be used, wherein the meter may be locked in a fixed position when the vessel is pitching, and when the seas

Problems solved by technology

While there have been some efforts to use information regarding environmental conditions, including ocean curr

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