| 摘要 |
A method and apparatus (28) is disclosed for efficient processing of NMR echo trains (fig.3) in well logging. A priori information about the nature of the expected signals is used to obtain an approximation of the signal using a set ofpre-selected basis functions (fig.5). A singular decomposition (SVD) is applied to a matrix incorporating information about the basis functions and is stored off-line a memory. During the actual measurement, the apparatus estimates a parameter related to the SNR of the received NMR echo trains and uses it to determine a signal approximation model in conjunction with the SVD of the basis function matrix. This approximation is used to determine in real time attributes (fig. 8) of the earth formation being investigated.
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