Seismic noise attenuation using dip map data structure

In a technological method of generating reduced-noise marine survey data that includes:

• generating, using a curvelet transform, transformed marine survey data from marine survey input data represented in an input domain, wherein the marine survey input data includes geophysical data indicative of geological structure, and wherein the marine survey input data contains noise;
• generating, using the curvelet transform, a transformed noise template from an input noise template, wherein the input noise template is indicative of predicted noise in the marine survey input data;
• applying a set of adaptation constraints to the transformed noise template to generate an adapted transformed noise template;
• removing noise from the transformed marine survey data using the adapted transformed noise template;
• and
• subsequent to noise removal, performing an inverse curvelet transform on the transformed marine survey data to generate reduced-noise marine survey data in the input domain;
• the specific improvement comprising:
• adapting a model of multiple noise to actual multiple events in the marine survey input data;
• estimating a multiple dip map from the adapted model of multiple noise;
• performing adaptive subtraction of the adapted model of multiple noise from the marine survey input data to generate a modified record of the marine survey input data, wherein the adaptive subtraction is sufficient to remove at least a majority of the multiple events;
• estimating a primary dip map from the modified record;
• and
• interpolating the primary dip map dependent upon the multiple dip map, wherein interpolating a given point of the primary dip map is dependent one or more neighboring points of the given point to a degree determined by the multiple dip map;
• wherein applying the set of adaptation constraints is performed dependent on relative amplitudes of the primary dip map and the multiple dip map, thereby controlling a degree of adaptation at a given point of the transformed noise template dependent upon the primary dip map and the multiple dip map, and thereby improving the removing of noise from the transformed survey data.

A system, comprising:

• a memory that stores instructions;
• and
• one or more processors configured to execute the instructions to perform operations that implement denoising of seismic data, the operations including:
• adapting a model of multiple noise to seismic data, thereby reducing a difference between the model and the seismic data, wherein the seismic data includes records of multiple events and primary events;
• generating a multiple dip map by convolving the adapted model of multiple noise with a set of directional filters;
• adaptively subtracting the adapted model of multiple noise from the seismic data to generate a modified record of the seismic data, wherein the adaptive subtraction is sufficient to remove at least a majority of the multiple events;
• determining a primary dip map from the modified record, wherein the determining includes interpolating the primary dip map dependent on the multiple dip map, thereby compensating for primary events that are masked by multiple events;
• performing adaptive subtraction of a noise template from the seismic data, thereby generating denoised seismic data, wherein prior to the adaptive subtraction, the noise template is adapted to the seismic data by a degree of adaptation that is determined dependent upon relative amplitudes of the primary dip map and the multiple dip map.

An apparatus for denoising seismic data, comprising:

• one or more computer systems having program storage and processing hardware, wherein the processing hardware is operable to execute instructions stored in the program storage to implement:
• means for adapting a model of multiple noise to seismic data;
• means for generating a multiple dip map from the adapted model of multiple noise;
• means for subtracting the adapted model of multiple noise from the seismic data;
• means for generating a primary dip map dependent upon the multiple dip map;
• and
• means for performing adaptive subtraction of an adapted noise template from the seismic data dependent upon the multiple dip map and the primary dip map, thereby generating denoised seismic data.