Skip to main content
U.S. Department of Energy
Office of Scientific and Technical Information

Determination of water saturation in earth formations independent of lithology

Patent ·
OSTI ID:5124979
A method is described for determining the water saturation of subsurface earth formations traversed by a borehole, substantially independent of salinity contrasts and lithology comprising steps of: traversing a borehole with a logging instrument to obtain first measurements functionally related to the electric permittivity of the formations surrounding the borehole. The electric permittivity is functionally related to the reservoir porosity, water filled porosity, hydrocarbon filled porosity and rock matrix; injecting into the formations an oil miscible solution to displace substantially all the residual fluids contained in the measured formations; injecting into the formations a sufficient amount of water to render the measured formations substantially one hundred percent water saturated; traversing the borehole with a logging instrument to obtain second measurements functionally related to the electric permittivity of the measured formations. The electric permittivity is functionally related to the reservoir porosity, water filled porosity and rock matrix; and combining the first and the second measurements to determine the water saturation for the measured formations substantially independent of salinity contrasts and lithology.
Assignee:
Dresser Industries, Inc., Dallas, TX
Patent Number(s):
US 4617517
OSTI ID:
5124979
Country of Publication:
United States
Language:
English