1. A computer implemented method for simulating attributes in a stratigraphic grid for determining a subsurface reservoir model, wherein the computer implements the method comprising: (a) creating the stratigraphic grid of nodes of the subsurface reservoir model; (b) creating a training image representative of subsurface geological heterogeneity; (c) creating a coarse grid of nodes corresponding to nodes of the stratigraphic grid; (d) simulating attributes at the nodes of the coarse grid utilizing well data to get informed nodes; (e) refining the coarse grid of nodes by adding uninformed nodes to the informed nodes to create a working grid of nodes; (f) selecting a data template of nodes from the working grid and building a search tree using the data template and the training image; (g) simulating attributes for the uninformed nodes of the working grid using the search tree; and (h) repeating steps (e)-(g) until the attributes of the nodes in the stratigraphic grid of the subsurface reservoir model have been simulated; wherein in at least one of the refining steps (e), the ratio of informed nodes to the total number of nodes in the working grid is greater than 1/4 for a 2D grid and greater than 1/8 for a 3D grid.