Systems and methods for noise attenuation of land continuous records
The present invention discloses systems and methods for attenuation of coherent environmental and source-generated noise in a continuously recorded domain of seismic survey testing. Rather than applying universal de-noising techniques to conventional gathers after source de-blending, the system and methods discussed herein focus on estimating and removing noise directly on continuous records by leveraging the noise characteristics in the domain of natural recording. Such techniques may equally be applied to coherent environmental and source-generated noises on seismic data as well as other data and noise types. Driven by the noise types encountered in the field, the methods of noise attenuation may be based upon time-frequency domain rank reduction techniques. Further, to model signal and/or noise, low-rank approximations are employed in conjunction with other techniques such as operator design and unsupervised learning.
1 . A method for processing seismic survey data, the method comprising:
obtaining, at a computing device, continuous seismic survey data of a survey location, the continuous seismic survey data collected by a seismic surveying system including a seismic source and one or more seismic sensors, each seismic sensor having a sensor identifier;
generating segmented seismic survey data by slicing the continuous seismic survey data into one or more segments grouped by the sensor identifier;
generating transformed seismic survey data by transforming the segmented seismic survey data into a time-frequency domain;
determining, based on the transformed seismic survey data, a phase-only operator of an mth order harmonic of a fundamental, wherein m=1, 2, . . . , M;
correlating the segmented seismic survey data with the phase-only operator of the mth order harmonic;
isolating and estimating a harmonic noise component of the mth order harmonic based on the phase-only operator of the mth order harmonic by applying a low-rank approximation to the continuous seismic survey data;
generating attenuated continuous seismic survey data by attenuating the transformed seismic survey data using the harmonic noise component of the mth order harmonic;
determining one or more subterranean features of the survey location using the attenuated continuous seismic survey data; and
plotting the one or more subterranean features of the survey location identified based on the attenuated continuous seismic survey data.
2 . The method of claim 1 , wherein attenuating the transformed seismic survey data using the harmonic noise component of the mth order harmonic comprises subtracting the harmonic noise component of the mth order harmonic from the transformed seismic survey data.
3 . The method of claim 2 , comprising removing the fundamental and a respective harmonic noise of the mth order harmonics sequentially by repeating m+1 times, for m=1, 2, . . . , M, for steps of isolating, estimating and subtracting.
4 . The method of claim 3 , comprising retaining primary reflections by adding back the fundamental.
5 . One or more tangible non-transitory computer-readable storage media storing computer-executable instructions for performing a computer process on a computing system, the computer process comprising:
obtaining continuous seismic survey data of a survey location, the continuous seismic survey data collected by a seismic surveying system including a seismic source and one or more seismic sensors, each seismic sensor having a sensor identifier;
generating segmented seismic survey data by slicing the continuous seismic survey data into one or more segments grouped by the sensor identifier;
generating transformed seismic survey data by transforming the segmented seismic survey data into a time-frequency domain;
determining, based on the transformed seismic survey data, a phase-only operator of an mth order harmonic of a fundamental, wherein m=1, 2, . . . , M;
correlating the segmented seismic survey data with the phase-only operator of the mth order harmonic;
isolating and estimating a harmonic noise component of the mth order harmonic based on the phase-only operator of the mth order harmonic by applying a low-rank approximation to the continuous seismic survey data;
generating attenuated continuous seismic survey data by attenuating the transformed seismic survey data using the harmonic noise component of the mth order harmonic;
determining one or more subterranean features of the survey location using the attenuated continuous seismic survey data; and
plotting the one or more subterranean features of the survey location identified based on the attenuated continuous seismic survey data.
6 . A system adapted to carry out a method processing seismic survey data, the system comprising:
a computing device having at least one processor configured to:
obtain continuous seismic survey data of a survey location, the continuous seismic survey data collected by a seismic surveying system including a seismic source and one or more seismic sensors, each seismic sensor having a sensor identifier;
generating segmented seismic survey data by slicing the continuous seismic survey data into one or more segments grouped by the sensor identifier;
generating transformed seismic survey data by transforming the segmented seismic survey data into a time-frequency domain;
determining, based on the transformed seismic survey data, a phase-only operator of an mth order harmonic of a fundamental, wherein m=1, 2, . . . , M;
correlating the segmented seismic survey data with the phase-only operator of the mth order harmonic;
isolating and estimating a harmonic noise component of the mth order harmonic based on the phase-only operator of the mth order harmonic by applying a low-rank approximation to the continuous seismic survey data;
generating attenuated continuous seismic survey data by attenuating the transformed seismic survey data using the harmonic noise component of the mth order harmonic;
determining one or more subterranean features of the survey location using the attenuated continuous seismic survey data; and
plotting the one or more subterranean features of the survey location identified based on the attenuated continuous seismic survey data.