Downhole Sensors Using Anisotropic Permittivity

Abstract

A apparatus for use in a borehole in an earth formation. The apparatus may include: an electromagnetic source; an anisotropic permittivity material, either natural or manufactured, receiving electromagnetic radiation from the electromagnetic source; and a detector for estimating the electromagnetic radiation transmitted through the anisotropic permittivity material as an indication of a parameter of interest. Also, a method of estimating a parameter of interest using the aforementioned apparatus.

We claim: 
     
         1 . An apparatus for use in a borehole, comprising:
 an anisotropic permittivity material; and   a detector configured to receive electromagnetic radiation transmitted through the anisotropic permittivity material and generate a signal in response thereto,   wherein the apparatus is configured for use in the borehole and wherein the anisotropic permittivity material is altered such that the material will respond to one or more selected stimuli so that the electromagnetic radiation received by the detector can be correlated to the stimuli.   
     
     
         2 . The apparatus of  claim 1 , further comprising an electromagnetic source configured to transmit electromagnetic radiation into the anisotropic permittivity material. 
     
     
         3 . The apparatus of  claim 1 , wherein the anisotropic permittivity material comprises one of: (i) a uniaxial property and (ii) a biaxial property. 
     
     
         4 . The apparatus of  claim 1 , further comprising a proof mass connected to the anisotropic permittivity material, wherein the signal is indicative of gravitational acceleration. 
     
     
         5 . The apparatus of  claim 1 , wherein the anisotropic permittivity material is responsive to a stimulus, the stimulus being at least one of: mechanical force, temperature, magnetism, electric potential, electric current, pressure, acceleration, gravity, electromagnetic radiation, nuclear radiation, and vibration. 
     
     
         6 . A method for estimating a parameter of interest, the method comprising:
 operating a sensor positioned in a borehole, comprising:
 an anisotropic permittivity material; and 
 a detector configured to receive electromagnetic radiation transmitted through the anisotropic permittivity material and generate a signal in response thereto, 
 wherein the apparatus is configured for use in the borehole and wherein the anisotropic permittivity material is altered such that the material will respond to one or more selected stimuli so that the electromagnetic radiation received by the detector can be correlated to the stimuli. 
   
     
     
         7 . The method of  claim 6 , further comprising illuminating the anisotropic permittivity material with electromagnetic radiation. 
     
     
         8 . The method of  claim 6 , further comprising estimating an angle of the electromagnetic radiation transmitted through the anisotropic permittivity material. 
     
     
         9 . The method of  claim 6 , further comprising calibrating the anisotropic permittivity material to a reference. 
     
     
         10 . The method of  claim 6 , wherein the anisotropic permittivity material comprises one of: (i) a uniaxial property and (ii) a biaxial property. 
     
     
         11 . The method of  claim 6 , wherein the anisotropic permittivity material is responsive to a stimulus, the stimulus being at least one of: mechanical force, temperature, magnetism, electric potential, electric current, pressure, acceleration, gravity, electromagnetic radiation, nuclear radiation, and vibration. 
     
     
         12 . The method of  claim 6 , wherein the parameter of interest is at least one of: mechanical force, temperature, magnetism, electric potential, electric current, pressure, acceleration, gravity, electromagnetic radiation, nuclear radiation, and vibration. 
     
     
         13 . A non-transitory computer-readable medium product, comprising:
 a processor; and   a set of instructions that, when executed, cause the processor to perform a method, the method comprising:
 estimating the parameter of interest using an apparatus comprising:
 an anisotropic permittivity material; and 
 a detector configured to receive electromagnetic radiation transmitted through the anisotropic permittivity material and generate a signal in response thereto, 
 wherein the apparatus is configured for use in a borehole and wherein the anisotropic permittivity material is altered such that the material will respond to one or more selected stimuli so that the electromagnetic radiation received by the detector can be correlated to the stimuli. 
 
   
     
     
         14 . The non-transitory computer-readable medium product as in  claim 13 , wherein the parameter of interest comprises at least one of: mechanical force, temperature, magnetism, electric potential, electric current, pressure, acceleration, gravity, electromagnetic radiation, nuclear radiation, and vibration. 
     
     
         15 . A method for manufacturing an apparatus for estimating a parameter of interest, comprising:
 forming the apparatus by operatively coupling a detector and a medium, wherein the permittivity of the medium has been altered in at least one direction such that the material will respond to one or more selected stimuli so that the electromagnetic radiation received by the detector can be correlated to the stimuli and wherein the apparatus is configured for use in a borehole.   
     
     
         16 . The method of  claim 15 , further comprising:
 operatively coupling an electromagnetic source to the apparatus.   
     
     
         17 . The method of  claim 15 , wherein the artificial alteration of the medium includes tuning the medium to be responsive to a desired stimulus, the desired stimulus including at least one of: mechanical force, temperature, magnetism, electric potential, electric current, pressure, acceleration, gravity, electromagnetic radiation, nuclear radiation, and vibration. 
     
     
         18 . The method of  claim 15 , wherein the artificial alteration of the medium includes inducing one of: (i) a uniaxial property and (ii) a biaxial property. 
     
     
         19 . The apparatus of  claim 1 , wherein the anisotropic permittivity material comprises a tuned anisotropic permittivity material. 
     
     
         20 . The method of  claim 6 , wherein the anisotropic permittivity material comprises a tuned manufactured anisotropic permittivity material.