RTM seismic imaging without scratch data storage system and method

A system for creating an image of sub-surface formations in a defined volume of a geological structure comprising:

• an array of receiver devices at or within said defined volume for recording data representing measurements of each wave produced by a shot of a sequence of plural shots;
• a distributed processing parallel computer device having a plurality of processing nodes interconnected through one or more networks, the one or more networks including a nearest-neighbor 3D torus communications network in which each processing node is connected to six nearest neighbor processing nodes, each of the six nearest neighbor processing nodes being equally distant from the each processing node to which the six nearest neighbor processing nodes are connected, each node having a respective processor device and a local memory storage device associated with the respective processor device,
• wherein one or more said processing nodes is assigned a processing block representing one partition of a partitioned velocity model domain representing geophysical wavefield propagation characteristics of a sub-surface structure of the earth in said defined volume, each processing block having an associated processing task for processing wave data associated with a shot;
• wherein a processor device at each node is configured to perform, in parallel, a method comprising:
• computing in parallel, using said associated processing tasks at each said processing node, data representing contributions of forward wave propagation data and reverse wave propagation at that node using said shot data;
• configuring each node for pipelined processing wherein said forward or reverse wave propagation data contributions are computed at the processing node and stored at said associated local memory storage device for current shot data while new data for a next shot is loaded into the local memory storage device at each node;
• and,
• combining, via the nearest-neighbor 3D torus communication network, said computed forward wave propagation data and reverse wave propagation data contributions stored at each node to form an imaging condition from which an image of sub-surface formations is created.

A computer program product for creating an image of sub-surface formations in a defined 2D or 3D volume of a geological structure, the computer program product comprising a storage medium readable by a processing circuit and storing instructions run by the processing circuit for performing a method, the method comprising:

• partitioning a velocity model domain representing geophysical wavefield propagation characteristics of a sub-surface structure of the earth in said defined volume into a plurality of blocks, each block having an associated processing task for processing wave data;
• receiving, at an array of receiver devices at a surface of or within said defined volume, data representing measurements of each wave produced by a shot of a sequence of plural shots;
• and
• assigning each partitioned domain block to one or more processing nodes of a distributed processing parallel computer device having a plurality of processing nodes interconnected through one or more communication networks, the one or more communication networks including a nearest-neighbor 3D torus communications network in which each processing node is connected to six nearest neighbor processing nodes, each of the six nearest neighbor processing nodes being equally distant from the each processing node to which the six nearest neighbor processing nodes are connected;
• computing in parallel, using said associated processing tasks at each said processing node, data representing contributions of forward wave propagation data and reverse wave propagation at that node using said shot data;
• configuring each node for pipelined processing wherein said forward or reverse wave propagation data contributions are computed at the processing node and stored at said associated local memory storage device for current shot data while new data for a next shot is loaded into the local memory storage device at each node;
• and,
• combining, via the nearest-neighbor 3D torus communication network, said computed forward wave propagation data and reverse wave propagation data contributions stored at each node to form an imaging condition from which an image of sub-surface formations is created.