Full waveform inversion using combined shot data and no scratch disk

摘要

A system, method and computer program product for seismic imaging implements a seismic modeling algorithm utilizing Forward Wave Inversion technique for revising Reverse Time Migration models used for sub-surface modeling. The technique requires large communication bandwidth and low latency to convert a parallel problem into one solved using massive domain partitioning. The partitioning of a velocity model into processing blocks allows each sub-problem to fit in a local cache, increasing locality and bandwidth and reducing latency. The RTM seismic data processing utilizes data that includes combined shot data, i.e., shot data selected from amongst a plurality of shots that are combined at like spatial points of the volume. An iterative approach is applied such that the correction term RTM generates at each iteration in the iterative approach is used for refining the model, and the updated model is used for generating a further refined RTM model.

主权项

1. A computer-implemented method for creating a Reverse Time Migration seismic model of sub-surface formations in a defined 2D or 3D volume of a geological structure using a Full Waveform Inversion computation, said method comprising:
partitioning a velocity model domain representing a subsurface structure of the earth in said defined volume into a plurality of blocks, each block having an associated processing task for processing wave data associated with a shot; assigning each partitioned domain block to processing nodes of a distributed processing parallel computer device having a plurality of processing nodes interconnected through one or more communication networks; receiving, at a local storage device associated with a respective processing node, a trace data representing measurement of each wave produced by a shot of a sequence of plural shots, each local storage device comprising a local cache or flash memory storage device coupled with a processor device at the processing node; computing, in parallel, using said associated processing tasks operating on said received trace data associated with a shot at each said processing node, contributions of forward wave propagation data and reverse wave propagation data at that node, said reverse wave propagation data computed using a residual data from forward wave propagation data computing, wherein said forward or reverse wave propagation data contributions are computed at the processing node and stored at the local cache or flash memory storage device at the processing node; and using said computed forward wave propagation data and reverse wave propagation data contributions stored at the local cache or flash memory storage device at the processing node to compute a correction term from which the seismic model is updated, the seismic model updating including, for each shot, iteratively performing:
computing, in parallel, said contributions of forward wave propagation data;obtaining said residual data representing a difference between said received trace data and data from said forward wave propagation computations;determining an accuracy of said seismic model based on said obtained residual data; andupdating said seismic model based on said determining, the updated seismic model minimizing an error in modeling the sub-surface formations.