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Determination of effective well block radii for numerical reservoir simulations
Author(s) -
Pritchett J. W.,
Garg S. K.
Publication year - 1980
Publication title -
water resources research
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.863
H-Index - 217
eISSN - 1944-7973
pISSN - 0043-1397
DOI - 10.1029/wr016i004p00665
Subject(s) - discretization , radius , block (permutation group theory) , grid , flow (mathematics) , mechanics , computer simulation , block size , reservoir simulation , mathematics , geometry , geology , computer science , physics , mathematical analysis , petroleum engineering , computer security , key (lock)
In the numerical simulation of underground reservoir behavior it is often necessary to employ well blocks (i.e., a grid block containing a well) with dimensions much larger than the well diameter. This paper develops practical procedures for making reasonable estimates of well bore sandface conditions from the well block conditions calculated by numerical reservoir simulations. It is assumed that on a sub‐grid scale, pressures will equilibrate much more rapidly than in the reservoir as a whole; the subgrid flow may therefore be treated as steady flow. The conditions at the sandface may then be deduced from mean well block conditions by assuming that the latter obtain at a definite distance (the ‘effective well block radius’) from the well. The problem is to establish the value of the effective well block radius in terms of the size of the well block and other relevant parameters. Grid pressures obtained in the numerical solution of liquid flow into a single well located in both radial and rectangular grid blocks are examined. It is found that the effective well block radius depends on, among other things, the shape of the grid block (radial or rectangular), the type of mesh (uniform or otherwise) employed, and the character of the spatial discretization scheme.