Method an system of geophysical exploration

A method for determining a quantitative measure of the minerals comprising the formations surrounding a wellbore, including the steps of:

• (a) obtaining a plurality of core samples of the earth's formations at selected intervals along substantially the entire wellbore length;
• (b) irradiating a portion of each core sample with infrared radiation and recording a spectral absorption response signal of the infrared radiation absorbed by said portion of each core sample;
• (c) locating the peaks in each spectral absorption response signal;
• (d) determining the relative amplitude of each peak in the spectral absorption response signal and
• (e) performing a regression analysis using the spectral location and relative amplitudes of the spectral absorption response signals using spectral locations and relative amplitudes for standard samples having a plurality of known mineral compositions to determine a quantitative measure of the minerals present in each core sample.

A method of evaluating the composition of minerals comprising the formations surrounding a wellbore, comprising the steps of:

• (a) obtaining a plurality of core samples of the earth's formations at selected intervals along substantially the entire wellbore length;
• (b) irradiating a portion of each core sample with infrared radiation and obtaining a Fourier transform absorption response signal representative of the infrared radiation absorbed by said portion of each core sample;
• (c) locating peaks in each Fourier transform response signal;
• (d) identifying minerals in each core sample by correlating the peaks in each Fourier transform absorption response signal with minerals exhibiting similar characteristic absorption peaks;
• and
• (e) producing a composition log of the minerals comprising the formations surrounding the wellbore along substantially its entire length from the minerals identified from core samples obtained at selected intervals along the wellbore length.

A method for determining a quantitative measure of minerals comprising a formation surrounding a wellbore, including the steps of:

• (a) obtaining a plurality of core samples of the earth's formation at selected intervals, corresponding to the minimum resolution intervals of a selected geophysical method of survey, along a wellbore length;
• (b) irradiating a portion of each core sample with electromagnetic radiation and recording a spectral absorption response signal of the electromagnetic radiation absorbed by said portion of each core sample;
• (c) locating peaks in each spectral absorption response signals;
• (d) determining the relative amplitude of each peak int eh spectral absorption response signal;
• and
• (e) performing a regression analysis using the spectral location and relative amplitude of the spectral absorption response signals using spectral locations and relative amplitudes for standard samples having a plurality of known mineral compositions to determine a quantitative measure of the minerals present in each core sample.