Fig. 9: Schematic diagram showing the microdroplet-induced model for organic-organic interactions and mass transfer among different species in thermal alkane–water-feldspar hydrous systems.
a Low temperature stystem without formation of microdroplets near the interface btween alkane and water zones. b Formation of microdeoplets near the alkane-water interface at elevated temperatures higher than 150 °C. c Occurrence of free radical reactions, ion reactions and mass exchanges in diffferent zones of the thermal alkane-water-feldspar system. In the water zone, water-derived ions react with minerals, lead to continuous mineral dissolution and precipitation, as well as H/O exchange between water and minerals. In the oil zone, high temperature facilitates the formation and recombination of alkane-derived free radicals, resulting in free radical thermal-cracking and cross-linking reactions. In the water–oil mix zone, water microdroplets form near the water–oil interface, trigging the formation of water-derived free radicals and initiating the organic–inorganic interactions between water and oil. The formation and recombination of water-derived and alkane-derived free radicals result in H/O exchange among water, alkanes, organic acids, CO2, and H2. These processes, with water serving as a bridge, erase the conventional boundaries between oil and minerals, facilitating the transfer of alkane/water/mineral-derived H/O among the newly formed organic and inorganic compounds.
