Karen S. Hoffman1, John W. Neave2
(1) Dynamic Graphics, Inc, Houston, TX
(2) Dynamic Graphics, Inc, Alameda, CA
ABSTRACT: Reservoir Characterization Using 3D Fault Restoration
Faulted reservoirs pose a particular problem for three-dimensional reservoir characterization using well data. Often there are a limited number of wells in each fault block; in order to distribute properties properly within the structural framework, data from one fault block must be used to influence the interpolation in surrounding fault blocks. This cannot be done unless the faulting is removed from the structure so that the interpolation can be done in geometrically restored space. A 3D geospatial modeling technique using a fault restoration methodology provides the necessary information to remove the faulting and shift the data to stratigraphic space. This is not merely a vertical shift, but allows for varying fault displacement and rotation of fault blocks. After the data have been shifted, a stratigraphic grid is superimposed on the data for interpolation. This grid may conform to surface boundaries, thus allowing a variety of internal truncations. Any interpolation technique may be used, such as deterministic or geostatistical methods. The resulting property model correctly shows the distribution of properties developed pre-faulting. This same technique can also be used in growth-faulted regimes. The geospatial technique allows expansion of section on one side of a fault. The interpolation may then be done as before, or may be confined to "super-blocks" composed of one or more individual fault blocks. The latter technique would interpolate the two sides of a growth fault independently. Reservoir management decisions may be made with greater confidence as the model provides the most rigorous representation of the data.
AAPG Search and Discovery Article #90906©2001 AAPG Annual Convention, Denver, Colorado