Detailed investigation of the pyrolysis process and new applications of the technique in organic geochemistry

Dry pyrolysis (Peak2) of source rocks and kerogens was found to be mainly affected by four parameters, organic matter content, pyrolysis heating rate, pseudo activation energy (E), and Arrhenius constant (A). Peak2 becomes larger but remains unchanged in position with increasing organic matter content. It moves to higher temperatures with increasing heating rate. It broadens and moves to higher temperature with increasing E. The effect of A is just the opposite; Peak2 narrows and moves to lower temperatures with increasing A.; In a whole pyrogram of a source rock, Peak1 was found to be formed from the free bitumen in pores. The process involved is a distillation process. Peak2 is formed from cracking of kerogen. The intermediate peaks are from the adsorbed bitumens on the mineral matrix and kerogen. The process involved is a desorption process. The high temperature tail on Peak2 is formed from secondary cracking of the adsorbed polar organic compounds on the mineral matrix.; E and A related to kerogen type and maturity. They can be used to indicate kerogen type and maturity. For different types of kerogen, E and A values are different at same maturity level. For one type of kerogen, E and A values are different at different maturity levels.; Pyrite was found to affect kerogen pyrolysis. It lowers Tmax (up to 14{dollar}spcirc{dollar}C) and E. It can change the yield and composition of pyrolysates. Pyrite converts to pyrrhotite during pyrolysis. The conversion temperature overlaps the temperature of kerogen cracking (with laboratory heating rates).; A model using pyrolysis data to simulate oil generation and migration was developed. The model can quantitatively time oil generation and migration from a source rock throughout its geological history. The mass balance method was introduced into the model.; Pyrolysis-gas chromatography of oil asphaltenes was found to be useful for correlating biodegraded oils. Oil asphaltenes can produce a "normal" gas chromatogram of the original oil.; Asphaltenes behave like kerogens during pyrolysis. Asphaltenes evolve at Peak2, overlapping with kerogen pyrolysis. Asphaltenes can be used to substitute kerogens for some geochemical research.