Methods for acquiring and processing seismic data from quasi-simultaneously activated translating energy sources

Abstract

A method for obtaining seismic data is disclosed. A constellation of seismic energy sources is translated along a survey path. The seismic energy sources include a reference energy source and a satellite energy source. The reference energy source is activated and the satellite energy source is activated at a time delay relative to the activation of the reference energy source. This is repeated at each of the spaced apart activation locations along the survey path to generate a series of superposed wavefields. The time delay is varied between each of the spaced apart activation locations. Seismic data processing comprises sorting the traces into a common-geometry domain and replicating the traces into multiple datasets associated with each particular energy source. Each trace is time adjusted in each replicated dataset in the common-geometry domain using the time delays associated with each particular source. This result in signals generated from that particular energy source being generally coherent while rendering signals from the other energy source is generally incoherent. The coherent and incoherent signals are then filtered to attenuate incoherent signals.

Description

TECHNICAL FIELD [0001] The present invention relates generally to seismic exploration, and more particularly, to acquiring and processing seismic data generated from generally simultaneously activated seismic energy sources. BACKGROUND OF THE INVENTION [0002] In the hydrocarbon exploration industry, remote sensing of underground geological formations using seismic waves provides information on the location, shape, and rock and fluid properties of potential hydrocarbon reservoirs. The standard technique comprises the activation of a source of acoustic energy which radiates seismic waves into the earth. These seismic waves reflect from and refract through subsurface geologic layers (acoustic illumination or insonification). The recording of these seismic waves by many different receivers (pressure or motion sensors) are ideally situated so as to optimize the ratio of information obtained to cost. This basic sourcing / insonification / recording procedure is repeated many times at slightly...

AI Technical Summary

Benefits of technology

[0009] This invention teaches a method for the acquisition of marine or land seismic data using quasi-simultaneously activated translating seismic sources whose radiated seismic energy is superposed and recorded into a common set of receivers. Also taught is the subsequent data processing required to separate these data into several independent records associated with each individual source. Quasi-simultaneous acquisition and its associated processing as described herein enable high quality seismic data to be acquired for greater operational efficiency, as compared to a conventional seismic survey.

[0012] It is an object of the present invention to provide a method for acquisition of seismic signals generated “quasi-simultaneously” from several moving separated sources activated with a small time delay, and their subsequent accurate separation during data processing into independent data sets exclusively associated with each individual source. This can greatly improve operational efficiency without compromising data resolution.

Problems solved by technology

This results in signals generated from that particular energy source being generally coherent while rendering signals from the other energy sources generally incoherent.

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