US 5,349,527 A · Method of seismic time migration using a massively parallel computer

Abstract

A method for 3 dimensional, one pass migration of post stack seismic data is implemented on a massively parallel computer. The quality of the migration and speed of execution makes possible iterative 3D post stack depth migrations. The depth migration method computes in the frequency domain and downward continues one or more frequency planes through all depth levels of interest. For a single frequency, at each depth level, the method extrapolates a shifted position for each x,y position by applying a filter for 2D convolution. A processing component is assigned to each subgrid of x,y spatial positions and the processing components operate concurrently in parallel to determine filter coefficients independently for each x,y spatial position and to extrapolate the x,y shifted positions. The filter coefficients are derived independently at each x,y position by storing a limited table of filter coefficients in local memory of each processing component.

Claims19

Dependent claims

A method for time migration of space-time domain seismic data to build a reflector time map using a parallel computer having a number of processing components, comprising the steps of:

(1) transforming the seismic data from the space-time domain x,y,t to a space frequency domain x,y,f data cube using a Fourier transform process;
(2) storing the space frequency data cube in computer memory;
(3) grouping one or more frequency planes from said space frequency data cube into frequency chunks;
(4) downwardly continuing the space frequency data cube for each frequency chunk through a number of time steps to obtain a reflector time map, where for each time step the method includes the substeps of
(a) modeling a velocity profile,
(b) loading a table of operator coefficients into memory,
(c) for a single frequency plane within the frequency chunk, assigning processing components to respective subgrids of one or more x,y spatial positions in the x,y plane,
(d) extrapolating all of the x,y spatial positions by concurrently operating several processing components in parallel, for each x,y position the extrapolation using the velocity profile and some of the operator coefficients from the table,
(e) building the reflector time map.

6 more elements

Dependencies are inferred from the claim text.

Method of seismic time migration using a massively parallel computer

Life of this patent

Method of seismic time migration using a massively parallel computer

Life of this patent

Abstract

Claims19