BACKGROUND

In the geothermal energy production, water is generally injected into a geothermal formation for heat extraction. The extracted hot water is then sent to a surface facility equipped with a steam turbine for power generation using a Rankine cycle. The steam from the turbine stage is cooled and sent to injection pumps for re-injection into the formation. Such energy production processes require a large scale facility and a high temperature formation, such as above 350° F. Also, matching energy supply and demand at remote geothermal locations is unfeasible. Accordingly, there is a need for an economically feasible method of geothermal energy production.

SUMMARY

In an embodiment, a method of generating electricity is disclosed. A working fluid is injected from a surface location into a wellbore having a work string disposed therein, the work string including a downhole turbine and a downhole generator. The working fluid absorbs heat from a formation surrounding the wellbore, generating a rotation at the turbine via the working fluid that has absorbed the heat, generating electricity at the generator from the rotation of the turbine. The electricity is transmitted to the surface location.

In another embodiment, a system for generating electricity is disclosed. The system includes a work string extending into a wellbore, a heat pump unit at a surface location for circulating a working fluid through the work string to absorb heat from a formation surrounding the wellbore, a turbine for generating a rotation from the working fluid that has absorbed the heat, a generator for generating electricity from the rotation of the turbine, and an electrical cable for transmitting the electricity to the surface location.

