Combined Vibrational Spectroscopy and Laser Induced Breakdown Spectroscopy for Improved Mineralogical and Geochemical Characterization of Petroleum Source or Reservoir Rocks

Abstract

A method for determining mineralogical or geochemistry of at least one geological sample with vibrational spectroscopy combined with laser-induced breakdown spectral measurements performed on the geological sample in a time variant manner with spectral acquisitions made after each of a plurality of measurement shots, spectral pre-processing performed as necessary, and subsequent analysis is applied to the collected data to determine at least one mineralogical or geochemistry parameter of the sample. The method can provide a rapid method to estimate mineralogy or geochemical parameters of a sample, which does not require sample preparation, and which can be non-destructive with respect to portions of the sample. A system for performing the method also is provided.

1 . A method for performing kinetic analysis as geochemical information of a sample of a petroleum source or reservoir rock, comprising:
 a) making a vibrational spectroscopy measurement on the sample of a petroleum source or reservoir rock;   b) heating the sample, or a second sample of the petroleum source or reservoir rock that has a similar composition and structure;   c) determining a reaction rate, such as a value of the Arrhenius equation rate constant k, of the sample of the second sample comprising at least one of:
 i) determining changes in amounts of elements associated with organic matter and hydrocarbons for a portion of the sample or the second sample that is heated by the laser-induced pyrolysis, 
 ii) collecting and analysing hydrocarbon species produced by pyrolysis of a portion of the sample from the laser-induced pyrolysis by a flame ion detector or gas chromatography-mass spectrometry (GC-MS), 
 iii) monitoring weight of the sample during the laser-induced pyrolysis of the sample, 
 iv) monitoring the temperature of the sample and determining the amount of energy inputted into the portion of the sample by the laser during the laser-induced pyrolysis, or using any combination of i), ii), iii), and iv). 
   
     
     
         2 . The method of  claim 1 , wherein a prefactor in the Arrhenius equation is inputted based on a priori knowledge or solved for based on measurements performed on two or more different heating rates of the sample. 
     
     
         3 . The method of  claim 1 , wherein the different heating rates are obtained by one or more of different laser power, laser spot size or laser shot rate, or any combination thereof. 
     
     
         4 . The method of  claim 1 , wherein the kinetic analysis by LIBS and vibrational spectroscopy is used to either solve for the activation energy distribution in the sample or the reaction rates given a known input of energy. 
     
     
         5 . A system for determining mineralogy or geochemistry of a sample, comprising:
 i) a vibrational spectral data acquisition device for obtaining vibrational spectral data on the sample;   ii) a LIBS spectral data acquisition device for obtaining LIBS spectral information on the sample, or a second sample of the petroleum source or reservoir rock that has a similar composition and structure;   iii) a spatial information acquisition device for obtaining spatial information on the sample, or a third sample of the petroleum source or reservoir rock that has a similar composition and structure, wherein the vibrational spectral data acquisition device, the LIBS spectral data acquisition device, and the spatial information acquisition device are the same device or different devices;   iv) one or more computer systems comprising at least one processor and a non-transitory computer-readable medium including a stored program comprising a set of instructions performed by the processor for carrying out steps to obtain mineralogy or geochemical information on the sample or the second sample using the spectral data, and to determine spatially resolved mineralogy or geochemical information for the sample, the second sample, or the third sample using the mineralogy or geochemical information and the spatial information; and   v) a device to display, print, and/or store as a non-transitory storage medium, results of the computations.