Finding porosity and oil fraction by means of dielectric spectroscopy
AssigneeBaker Hughes Incorporated
InventorVitaly Nikolaevich Dorovsky
Life of this patent
Estimating the term…
Abstract
Methods, systems, devices and products for evaluating an earth formation. Methods include estimating at least one property of the earth formation using at least one polarization parameter estimated using a real part and an imaginary part of a permittivity of the earth formation at a plurality of frequencies, where the real parts and the imaginary parts are based on measurements obtained using an electromagnetic tool in a borehole penetrating the earth formation.
Claims16
A method of evaluating an earth formation including a porous medium, the method comprising:
- making a plurality of estimates of complex permittivity based on measurements at at least one receiver on an electromagnetic tool responsive to electromagnetic signals transmitted at a plurality of frequencies in a borehole penetrating the earth formation from a transmitter in the borehole;
- and
- estimating a parameter of interest of the earth formation using the plurality of estimates by using a spectral dielectric curve constant (v) for the porous medium, the spectral dielectric curve constant (v) invariant with respect to water-oil ratio in the porous medium and determined by an estimated rate of change between estimates of the plurality of estimates of complex permittivity of an imaginary part relative to a real part of each estimate, comprising:
- generating a spectral dielectric curve by mapping the real part with respect to the imaginary part for each estimate of the plurality of estimates;
- using at least one processor to perform at least one of:
- i) storing the parameter in a computer memory;
- ii) transmitting the parameter uphole;
- or iii) displaying of the parameter to an operating engineer.
An apparatus for evaluating an earth formation, the apparatus comprising:
- a carrier configured to be conveyed in a borehole penetrating the earth formation;
- a electromagnetic tool disposed on the carrier and configured to make a plurality of estimates of complex permittivity based on measurements at at least one receiver on the tool responsive to electromagnetic signals transmitted at a plurality of frequencies in a borehole penetrating the earth formation from a transmitter in the borehole;
- and
- a processor configured to estimate a parameter of interest of the earth formation by using a spectral dielectric curve constant (v) for the porous medium, the spectral dielectric curve constant (v) invariant with respect to water-oil ratio in the porous medium and determined by an estimated rate of change between estimates of the plurality of estimates of complex permittivity of an imaginary part relative to a real part of each estimate, comprising:
- generating a spectral dielectric curve by mapping the real part with respect to the imaginary part for each estimate of the plurality of estimates;
- using at least one processor to perform at least one of:
- i) storing the parameter in a computer memory;
- ii) transmitting the parameter uphole;
- or iii) displaying of the parameter to an operating engineer.
Dependencies are inferred from the claim text.