Well Log Data Ming
GMM
assumes that one well log matrix is one mixture model, which is a probabilistic
model. This method transforms well log data into Gaussian distribution, with
the parameters
. The objective
function of EM algorithm is the likelihood of the GGM. The likelihood
maximization is shown as follows:
EM
can give a relatively accurate approximation after iterations.
The figure of GMM clustering results is as follows:
Well
Correlation
It
enables people to do well correlation by generating electrofacies after
applying model-based clustering. Then the paper determines the size of the
sample and select sample points with systematic sampling method.
Discriminant
analysis (DA) it is a classification method where clusters from populations are
known to be a priori, assuming that different classes generate data based on
different Gaussian distributions.
To
facilitate future improvement, we can use core analysis to calibrate well
correlation results.
Well Log Data
Postprocessing
Artificial
neural network (ANN)
It
is a dynamic computation system which is capable of extracting and recognizing
the underlying dominant patterns among data, classifying new patterns and
generalizing an output based on the learned data.
Feedforward
back-propagation is a common scheme for training the network.
The figure of pairwise well prediction results is as follows:
Conclusions
The
system consists of three components: data preprocessing, data mining and data
postprocessing. The data are normalized, reduced in dimension, modeled and
selected, then correlated, finally predicted and generated.
(Some of the equations cannot be shown in the Blogger. Tomorrow,
I plan to read the paper again and find something useful for pseudo well log.)
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