Abstract: A method for determining mineralogy of a formation includes determining a model of arenites in the formation by performing a first type of linear regression on a plurality of elemental dry weights of the formation based upon a sum of elemental dry weights of calcium and magnesium being at least a given value, or performing a second type of linear regression on the elemental dry weights based upon the sum of the elemental dry weights of elemental calcium and magnesium being less than the given value. A model of arkoses in the formation is determined by performing a third type of linear regression on the elemental dry weights. A partitioning function is then determined. The mineralogy of the formation is then determined by applying the partitioning function to the model of arenites and the model of arkoses, and adding the model of arenites and the model of arkoses together.

Abstract: The accurate determination of formation hydrocarbon or water saturation is a useful step in the petrophysical evaluation of petroleum reservoirs. This disclosure presents a new method for estimating hydrocarbon saturation directly from a porosity log and a total organic carbon (TOC) log. The method is enabled by the recent development of a geochemical spectroscopy logging tool that combines inelastic and capture gamma ray measurements to provide a robust and accurate TOC log. The method differs from the prior approach of using carbon-to-oxygen ratios that is most often applied in cased hole evaluation. The main advantages of this method are that it does not use knowledge of formation water resistivity, it does not rely on a resistivity model, it does not use an extensive calibration database, and it is largely independent of clay or other lithology effects.

Abstract: A method for predicting at least one property of a geological formation may include generating mapping function values relating a plurality of reference elemental compositions to corresponding reference properties thereof based upon at least one non-linear mapping function. The method may further include determining a sample elemental composition of at least one sample associated with the geological formation and performing, using a processor, an interpolation to map the sample elemental composition to at least one sample property based upon the mapping function values and the at least one non-linear function.

Abstract: The subject disclosure relates to the evaluation of lithology, mineralogy and organic content of earth materials. More particularly, the subject disclosure relates to evaluating lithology, mineralogy and organic content of earth materials using diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS).

Abstract: Systems and methods are described for analyzing hydrocarbon bearing earth samples to determine information indicating the maturation, or changes in composition of kerogen from original deposition over geologic time as the kerogen is subjected to heat and pressure. A DRIFTS spectrometry signal is corrected and normalized and then plotted against TOC data to obtain an index indicating thermal maturity.

Abstract: The accurate determination of formation hydrocarbon or water saturation is a useful step in the petrophysical evaluation of petroleum reservoirs. This disclosure presents a new method for estimating hydrocarbon saturation directly from a porosity log and a total organic carbon (TOC) log. The method is enabled by the recent development of a geochemical spectroscopy logging tool that combines inelastic and capture gamma ray measurements to provide a robust and accurate TOC log. The method differs from the prior approach of using carbon-to-oxygen ratios that is most often applied in cased hole evaluation. The main advantages of this method are that it does not use knowledge of formation water resistivity, it does not rely on a resistivity model, it does not use an extensive calibration database, and it is largely independent of clay or other lithology effects.

Abstract: A method for determining mineralogy of a formation includes determining a model of arenites in the formation by performing a first type of linear regression on a plurality of elemental dry weights of the formation based upon a sum of elemental dry weights of calcium and magnesium being at least a given value, or performing a second type of linear regression on the elemental dry weights based upon the sum of the elemental dry weights of elemental calcium and magnesium being less than the given value. A model of arkoses in the formation is determined by performing a third type of linear regression on the elemental dry weights. A partitioning function is then determined. The mineralogy of the formation is then determined by applying the partitioning function to the model of arenites and the model of arkoses, and adding the model of arenites and the model of arkoses together.

Abstract: A method for predicting at least one property of a geological formation may include generating mapping function values relating a plurality of reference elemental compositions to corresponding reference properties thereof based upon at least one non-linear mapping function. The method may further include determining a sample elemental composition of at least one sample associated with the geological formation and performing, using a processor, an interpolation to map the sample elemental composition to at least one sample property based upon the mapping function values and the at least one non-linear function.

Abstract: The subject disclosure relates to the evaluation of lithology, mineralogy and organic content of earth materials. More particularly, the subject disclosure relates to evaluating lithology, mineralogy and organic content of earth materials using diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS).

Abstract: Methods and apparatus are provided for determining the content of a first element in a formation which cannot otherwise be determined via a capture spectrum measurement. The methods and apparatus utilize the inelastic spectrum measurement of the first element and the inelastic and capture spectrum measurements of at least a second element. The methods and apparatus have particular application to determining the carbon content of a formation although they are not limited thereto. The inelastic and capture spectrum measurements of silicon are useful in making such determinations, although other chemical elements may be used as the second element.

Abstract: Methods and apparatus are provided for determining the content of a first element in a formation which cannot otherwise be determined via a capture spectrum measurement. The methods and apparatus utilize the inelastic spectrum measurement of the first element and the inelastic and capture spectrum measurements of at least a second element. The methods and apparatus have particular application to determining the carbon content of a formation although they are not limited thereto. The inelastic and capture spectrum measurements of silicon are useful in making such determinations, although other chemical elements may be used as the second element.