Poly-generation energy system driven by associated geothermal water for oilfield in high water cut stage: A theoretical study

Onshore oilfields are also geothermal fields. In order to reduce cost of geothermal wells and simultaneously improve the energy efficiency of geo-plants, a poly-generation energy system driven by associated geothermal water was established for oilfield in high water cut stage. The system consists of four parts: the power generation subsystem, the absorption chiller subsystem, the oil gathering and transportation heat tracing (OGTHT) subsystem and the radiant heating subsystem, and it realizes the combined cooling, heat, power generation, and oil recovery (CCHPOR), with the associated geothermal water ranging from 373.15 K to 423.15 K. The impact of the heat source temperature and the evaporation temperature on system performance was analyzed. The results show that the performances including net power output, thermal efficiency, exergy efficiency, of the TSORC (two-stage series organic Rankine cycle) are better than those of the ORC, and the total energy efficiency of the CCHPOR reaches 75%. Moreover, the CCHPOR system can prolong the effective life of oil wells, especially for those in high water cut stage, which can be adopted in engineering applications.