Source Rock Analysis

Definition List

S1 (free oil)

The amount of thermally freed hydrocarbons in the sample in milligrams hydrocarbons per gram of rock (mg HC/g rock).

Pyrolysis pyrogram - S1 peak highlighted

S2 (kerogen yield)

The amount of hydrocarbons generated through thermal cracking of non-volatile organic matter. S2 is an indication of the quantity of hydrocarbons that the rock has the potential of producing under increased burial and maturation. This is the kerogen yield. S2 measurements are reported in milligrams hydrocarbons per gram of rock (mg HC/g rock).

Pyrolysis Pyrogram - S2 peak highlighted

S3 (organic carbon dioxide yield)

The amount of CO2 in milligrams CO2 per gram of rock produced during pyrolysis of kerogen (mg CO2/g rock). This is a measure of the organic carbon dioxide yield of the rock. S3 is an indication of the amount of oxygen in the kerogen.

Pyrolysis Pyrogram - S3 peak highlighted


Milligrams of carbon per gram or rock produced from the organic residue remaining after pyrolysis of kerogen is completed (mg C/g rock).

Tmax (maturity)

The temperature at which the maximum generation of hydrocarbons from cracking of kerogen occurs during pyrolysis. This is the temperature at the top of the S2 peak. Measurements of Tmax are reported in °C. Tmax is an indicator of thermal maturity.

Pyrolysis pyrogram - Tmax indicated

TOC (Total Organic Carbon)

measure of the Total Organic Carbon content of the rock in weight percent (wt. %).

CC (Carbonate Carbon)

Measure of the inorganic carbon content of the rock and is derived from the mineral carbonate content of the rock (wt. %).

Absolute Tmax for kinetics calculations
Coming Soon

Plus the following interpretative calculations:

  • Adsorption Index (AI)
  • Oil Saturation Index(OSI)
  • Hydrogen index (HI)
  • Oxygen index (OI)
  • Production index (PI)
  • Generative Organic carbon (GOC)
  • non-generative organic carbon (NGOC)