Investigation On The Mechanism Of Multi-fluid Injection For Heat Extraction In Geothermal Reservoir

Geothermal energy extraction is becoming a global sensational solution for the oil&gas industry to switch to renewable energies.Application of geothermal heat mining coupled with non-condensable gases like CO₂ and N₂ as main heat transfer fluid has gain great attention amongst researchers.Unlike using water as extraction fluid,these non-condensable gases have found to have significant heat mining rate for a specific thermal reservoir.This work presents analysis on the influences of multi-fluid injection,including the non-condensable gases towards heat extraction.Using a computational optimization tool CMG-CMOST,a selection of combinational mix of water with CO₂ and N₂ under specific mole fraction was proposed in order to maximize the potential heat extraction from the geothermal reservoir.Field scale numerical simulations under CMG-STARS module was considered taking an actual case study of Baobab field in the Bongor basin,Chad.The results analysis showed that deployment of geothermal projects at Bongor basin is possible considering at hand the geological parameters that favors effective heat mining.Furthermore,in faulted geothermal reservoirs,the fault’s conduit and sealing properties played an important role towards choosing the appropriate development plan.Numerical simulation of a proposed field plan consisting of 22 injectors and 22 producers considered multi-component system over single component system.Comparison in terms of heat mining efficiency between the native water system and the potential suggested multi-component system was performed.Under similar conditions to water only system,the use of multi-fluid system for heat extraction offered a remarkable drive to due to the extra pressure drive exerted by the two non-condensable gases within reservoir.Furthermore,using CO₂ as heat extraction fluid potentially promoted CO₂ sequestration as most of the injected fluid will remain in the thermal reservoir.