oa New Insights into Water Influence on Organic Matter Transformations During Aqueous Pyrolysis in a Closed System

Injection of supercritical/hot water in unconventional reservoirs is a perspective technology for petroleum production, as it allows to convert kerogen and heavy oil fractions into mobile hydrocarbons. Water is not only a good heating agent due to high heat capacity, but also a reactant and a solvent for polar fractions, affecting the pyrolysis products composition. The new insights were obtained during studies on early mature type II kerogen thermal decomposition during aqueous closed-system pyrolysis in a wide temperature range. Particularly, this study revealed the significant influence of water on pyrolysis products composition and kinetics of kerogen decomposition: 1) transformations of non-pyrolyzable kerogen part in temperature range 360-380?; 2) consequent acceleration of the whole process in aqueous closed system comparing to open system; 3) elevated CO2 and H2 yields due to water-gas shift reaction. These phenomena can be taken into account during planning of in-situ kerogen conversion and choice of optimal regime for hot water injection