MINIMIZING LOG ANALYSIS ERRORS: THE USE OF OPTIMIZING PETROPHYSICS – GHAWAR FIELD
Ramsin Y. Eyvazzadeh
Stephen G. Cheshire
Rami H. Nasser
David G. Kersey
SAUDI ARAMCO JOURNAL OF TECHNOLOGY FALL 2004
ABSTRACT
The transformation of borehole logging measurements into
accurate and precise porosity, lithology, permeability and
fluid saturation data is the most important result of a
petrophysical analysis. A fundamental petrophysical
problem is how to minimize systematic and random errors
associated with data acquisition from different logging
tools, variable borehole conditions and reservoir properties.
Historically, errors were minimized by increasing the
number of logs and/or calibration of results to core data. In
the 1980’s, a major development in petrophysics was the
ability to utilize error minimizing routines to optimize the
accuracy of petrophysical results. This optimization analysis
combines input data with a set of response functions to find
the best solution by minimizing the differences between
predicted answers and actual inputs. Even though this
technique appears to have technical advantages, acceptance
has been limited due to underlying complex mathematics,
and consequently, the process is less understood. A recent
study was completed to determine the strengths and
weaknesses of this type of analysis on Ghawar field, Saudi
Arabia. Due to its vast areal extent, unique reservoir
properties and extensive logging and core data, this field
provided an ideal basis to evaluate optimizing analytical
models. Data from several logging companies was used to
show the combined effects of tool types and vintages,
borehole conditions and reservoir properties on the utility
of optimized petrophysical methods in Ghawar field.
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http://ipac.kacst.edu.sa/eDoc/eBook/768.pdf
Отправлено: 22.05.11 09:58. Заголовок: MINIMIZING LOG ANALYSIS ERRORS: THE USE OF OPTIMIZING PETROPHYSICS – GHAWAR FIELD
