Identifying formation, matrix and fluid related characteristics from subsurface data using factor analysis

摘要

A method of interpreting petrophysical measurement data include arranging measurements of at least one physical property of formations into a matrix representing the measurements and selecting a range of number of unobserved factors or latent variables for factor analysis. Factor analysis is performed on the measurement matrix and comprises performing factorization of measurements matrix into a number of factorsand performing rotation of the factorization results. Whether the factor loadings for each factor have achieved a “simple structure” is determined and either each of the selected number of factors is associated with a physical parameter of the formations, or one is added to the number of factors and factor analysis and rotation are repeated until factor loadings of all factors have achieved “simple structure” such that the each of the number of factors is associated with a physical property of the formations.

主权项

1. A method for interpreting petrophysical measurement data, comprising:
measuring at least one physical property of formations using a petrophysical measuring instrument in a wellbore; in a computer, arranging measurements of the at least one physical property of formations made by the petrophysical measuring instrument into a matrix representing the measurements and selecting a number of unobserved factors for factor analysis; in the computer, performing factorization of the matrix into the number of unobserved factors; in the computer, performing rotation of results of the factorization; in the computer, determining whether factor loadings for each of the unobserved factors has achieved a simple structure; and in the computer, when it is determined that each of the unobserved factors cannot be associated with a corresponding physical parameter of the formations, performing the following operations until each of the unobserved factors has achieved the simple structure such that each of the unobserved factors is associated with the corresponding physical parameter of the formations:
adding one to the number of factors; andrepeating the performing factorization of the matrix, repeating the performing rotation of the results of the factorization, and repeating the determining whether factor loadings for each of the unobserved factors has achieved the simple structure.