Microwave apparatus and method for determination of adsorbed fluid in subsurface formations surrounding a borehole

A method of determining the amount of adsorbed fluid in formations surrounding a borehole, comprising the steps of:

• deriving a first quantity which is a function of the dielectric constant of said formations as measured by passing microwave electromagnetic energy of a first frequency through said formations;
• deriving a second quantity which is a function of the dielectric constant of said formations as measured by passing microwave electromagnetic energy of a second frequency through said formations;
• and
• determining the amount of adsorbed water in said formations as a function of said first and second quantities.

Apparatus for determining the amount of adsorbed water in formations surrounding a borehole, comprising:

• means for injecting microwave electromagnetic energy at first and second frequencies into the surrounding formations;
• means for measuring the relative attenuation and relative phase shift of the microwave electromagnetic energy passing through a given portion of the surrounding formations;
• means for deriving a first quantity which is a function of the measured attenuation and phase shift at said first frequency;
• means for deriving a second quantity which is a function of the measured attenuation and phase shift at said second frequency;
• and
• means for determining the amount of adsorbed water in said given portion of the surrounding formations as a function of said first and second quantities.

A method for determining the amount of adsorbed water in formations surrounding a borehole, comprising the steps of:

• injecting microwave electromagnetic energy at first and second frequencies into the surrounding formations;
• measuring the relative attenuation and phase shift of the microwave electromagnetic energy passing through a given portion of the surrounding formations;
• deriving a first quantity which is a function of the measured attenuation and phase shift at said first frequency;
• deriving a second quantity which is a function of the measured attenuation and phase shift at said second frequency;
• and
• determining the amount of adsorbed water in said given portion of the surrounding formations as a function of said first and second quantities.

Apparatus for determining the amount of adsorbed water in formations surrounding a borehole, comprising:

• means for injecting microwave electromagnetic energy at first and second frequencies into the surrounding formations;
• means for measuring the relative attenuation and relative phase shift of the microwave electromagnetic energy passing through a given portion of the surrounding formations;
• means for deriving a first quantity which is indicative of the loss-corrected dielectric constant of the given portion of the formations by combining the attenuation and phase measurements taken at said first frequency;
• means for deriving a second quantity which is indicative of the loss-corrected dielectric constant of the given portion of the formations by combining the attenuation and phase measurements taken at said second frequency;
• and
• means for determining the amount of adsorbed water in said given portion of the surrounding formations as a function of said first and second quantities.

A method for determining the amount of adsorbed water in formations surrounding a borehole, comprising the steps of:

• injecting microwave electromagnetic energy at first and second frequencies into the surrounding formations;
• measuring the relative attentuation and relative phase shift of the microwave electromagnetic energy passing through a given portion of the surrounding formations;
• deriving a first quantity which is indicative of the loss-corrected dielectric constant of the given portion of the formations by combining the attenuation and phase measurements taken at said first frequency;
• deriving a second quantity which is indicative of the loss-corrected dielectric constant of the given portion of the formations by combining the attenuation and phase measurements taken at said second frequency;
• and
• determining the amount of adsorbed water in said given portion of the surrounding formations as a function of said first and second quantities.