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U.S. Department of Energy
Office of Scientific and Technical Information

Well logging analysis methods for use in complex lithology reservoirs

Patent ·
OSTI ID:7247749
This patent describes a machine implemented iterative method of well log analysis to determine the volumes of anhydrite (or gypsum) in three mineral combination lithology utilizing well log measurements of gamma-gamma density, neutron and acoustic properties of earth formations in the vicinity of a well borehole. The method comprises: (a) obtaining a gamma-gamma density versus neutron porosity crossplot from the respective logs at a corresponding depth in the well borehole; (b) determining rho/sub map/ (the average density of rock matrix) and ..delta..t/sub map/ (the average matrix acoustic travel time) by solving the crossplot for two mineral lithology; using the rho/sub map/ and ..delta..t/sub map/, then determining the volume of anhydrite (or gypsum) present.
Assignee:
Halliburton Co., Duncan, OK
Patent Number(s):
US 4617825
OSTI ID:
7247749
Country of Publication:
United States
Language:
English