Measurement of formation rock properties by diffusion

Abstract

Embodiments of the present invention relate to a method to determine formation measurements, the method comprising placing a sample in a reservoir, removing aliquots from the reservoir containing the sample or continuously monitoring the reservoir or headspace as the sample and reservoir equilibrate and analyzing the aliquots or readings sufficient to provide diffusion measurements.

1 . A method to determine formation measurements, the method comprising:
 collecting a plurality of formation samples;   analyzing a first formation sample of the plurality to determine a salinity of the first formation sample;   sufficiently matching a salinity of fluid in a reservoir to the salinity of the first formation sample;   placing a second formation sample of the plurality in the fluid of the reservoir; and   analyzing the fluid in the reservoir as the second formation sample and fluid equilibrate sufficient to provide diffusion measurements.   
     
     
         2 . The method of  claim 1 , wherein analyzing the fluid in the reservoir includes removing aliquots from the fluid as the second formation sample and fluid equilibrate sufficient to provide diffusion measurements. 
     
     
         3 . The method of  claim 2 , further comprising, before removing aliquots, agitating the fluid and the second formation sample in the reservoir. 
     
     
         4 . The method of  claim 2 , wherein the aliquots are liquid samples from the reservoir. 
     
     
         5 . The method of  claim 2 , wherein the aliquots are vapor samples from the headspace of the reservoir. 
     
     
         6 . The method of  claim 1 , further comprising the step of measuring the surface area of the second formation sample, sufficient to provide surface area measurements. 
     
     
         7 . The method of  claim 6 , further comprising the step of calculating formation information from the surface area measurements and diffusion measurements, sufficient to provide porosity and permeability information. 
     
     
         8 . The method of  claim 1 , wherein the second formation sample comprises cuttings. 
     
     
         9 . The method of  claim 1 , wherein the second formation sample comprises a core. 
     
     
         10 . The method of  claim 1 , wherein the reservoir comprises essentially an isotopically labeled species fluid. 
     
     
         11 . The method of  claim 10 , wherein the reservoir further comprises essentially deuterated water. 
     
     
         12 . The method of  claim 10 , wherein the reservoir comprises essentially 180 water. 
     
     
         13 . The method of  claim 1 , wherein the analysis is performed by spectroscopy. 
     
     
         14 . The method of  claim 13 , wherein the analysis if further performed by laser spectroscopy. 
     
     
         15 . A method to determine formation measurements, the method comprising:
 collecting a plurality of formation samples;   analyzing a first formation sample of the plurality to determine a salinity of the first formation sample;   sufficiently matching a salinity of fluid in a reservoir to the salinity of the first formation sample using information about the salinity of the first formation sample;   placing a second formation sample of the plurality in the reservoir;   analyzing the fluid in the reservoir as the second formation sample and fluid equilibrate sufficient to provide diffusion measurements;   measuring the surface area of the second formation sample, sufficient to provide surface area measurements; and   calculating formation information from the surface area measurements and diffusion measurements, sufficient to provide porosity and permeability information.   
     
     
         16 . The method of  claim 15 , wherein analyzing the fluid in the reservoir includes removing aliquots from the fluid as the second formation sample and fluid equilibrate sufficient to provide diffusion measurements. 
     
     
         17 . A method to determine formation measurements, the method comprising:
 placing a formation sample in a fluid reservoir, the formation sample comprising a plurality of cuttings from the formation; and   analyzing the reservoir fluid as the sample and reservoir equilibrate, sufficient to provide diffusion measurements.   
     
     
         18 . The method of  17 , wherein the headspace of the reservoir is analyzed. 
     
     
         19 . The method of  claim 17 , further comprising before analyzing the reservoir, agitating the sample in the reservoir. 
     
     
         20 . The method of  claim 17 , further comprising before placing a sample in a reservoir, adjusting a salinity in a reservoir. 
     
     
         21 . The method of  claim 17 , further comprising the step of measuring the surface area of the sample, sufficient to provide surface area measurements. 
     
     
         22 . The method of  claim 21 , further comprising the step of calculating formation information from the surface area measurements and diffusion measurements, sufficient to provide porosity and permeability information. 
     
     
         23 . The method of  claim 17 , wherein the analysis is performed by spectroscopy. 
     
     
         24 . The method of  claim 23 , wherein the analysis if further performed by laser spectroscopy. 
     
     
         25 . A method to determine formation measurements, the method comprising:
 collecting a plurality of samples;   analyzing a first sample to determine a salinity of the first sample;   using information about the salinity of the first sample to sufficiently match a salinity of fluid in a reservoir to a reasonable degree of accuracy;   placing a second sample in the reservoir;   analyzing the reservoir fluid as the second sample and reservoir fluid equilibrate, sufficient to provide diffusion measurements;   measuring the surface area of the second sample, sufficient to provide surface area measurements; and   calculating formation information from the surface area measurements and diffusion measurements, sufficient to provide porosity and permeability information.   
     
     
         26 . A method to determine formation measurements, the method comprising:
 adjusting a salinity in a reservoir;   placing a sample in the reservoir;   analyzing a headspace of the reservoir as the sample and reservoir equilibrate, sufficient to provide diffusion measurements;   measuring the surface area of the sample, sufficient to provide surface area measurements; and   calculating formation information from the surface area measurements and diffusion measurements, sufficient to provide porosity and permeability information.