The invention discloses an oil-rich
coal in-situ
pyrolysis system and method for multi-fluid synergistic
heat supply and
coke suppression and oil increase. The
system adopts an orthohexagonal underground
pyrolysis network comprising a
combustion input / output well, a heat
injection well and a production well, in-situ controllable
combustion is utilized to release heat, and high-temperature supercritical CO2 is coupled to perform
convection heating on a
coal seam; low-temperature supercritical CO2 is sprayed in an independent fluid channel of a production well and is in direct contact with a
pyrolysis product for heat exchange, and a liquid collecting and heating pumping device at the bottom of the well is matched, so that secondary reaction of
tar is effectively inhibited, and the flowability is improved;
superheated steam pulse type injection is adopted,
carbon deposition is removed under the action of a catalyst
bed layer, coking is blocked, pores are dredged, and after pyrolysis is finished, steam is continuously injected to achieve gasification exploitation of residual semicoke. The
system integrates the functions of
combustion heat supply, supercritical CO2 heat carrying /
shock cooling, steam gasification
coke suppression, multi-stage
waste heat recovery and the like, and the
tar yield, quality and energy utilization efficiency of oil-rich
coal in-situ mining are remarkably improved.