Disclosed herein are various embodiments of systems for drilling and operating a well which may have dual uses. The well may be drilled and operated as a geothermal well using a hybrid approach where a heat transfer fluid is injected into a hot rock formation but is not removed, and heat is extracted using a closed loop method. The geothermal well is then evaluated for use as a carbon dioxide sequestration well. In other embodiments, the well is drilled as a carbon dioxide sequestration well and then evaluated for its potential for generating geothermal energy using a hybrid approach where supercritical carbon dioxide is injected into a hot rock formation but is not removed, and heat is extracted using a closed loop method. Both horizontal and vertical wells are disclosed, in sedimentary rocks and in basement granite.

Disclosed herein are various embodiments of systems for drilling and operating a well which may have dual uses. The well may be drilled and operated as a geothermal well using a hybrid approach where a heat transfer fluid is injected into a hot rock formation but is not removed, and heat is extracted using a closed loop method. The geothermal well is then evaluated for use as a carbon dioxide sequestration well. In other embodiments, the well is drilled as a carbon dioxide sequestration well and then evaluated for its potential for generating geothermal energy using a hybrid approach where supercritical carbon dioxide is injected into a hot rock formation but is not removed, and heat is extracted using a closed loop method. Both horizontal and vertical wells are disclosed, in sedimentary rocks and in basement granite.

A heat-pipe type heat extraction integrated with combined cooling power and heating exploitation-utilization integrated geothermal system includes an underground heat pipe, a steam pump, a first absorption bed, a second absorption bed, a first condenser, an electronic expansion valve, an evaporator, a liquid storage tank, a balance valve, a steam turbine, an generator connected to the steam turbine, a second condenser, a heat utilization device connected to the second condenser, a pressurizing pump connected to the second condenser, and relevant linkage valve assemblies. The system controls a flow direction and a flow rate after heat pipe steam is extracted from the ground through the steam pump and the regulating valves on the refrigeration side and the power generation side, so as to select the refrigeration/electric heating single-mode heat utilization or adjust flow distribution during refrigeration/electric heating dual-mode combined use.

A heat-pipe type heat extraction integrated with combined cooling power and heating exploitation-utilization integrated geothermal system includes an underground heat pipe, a steam pump, a first absorption bed, a second absorption bed, a first condenser, an electronic expansion valve, an evaporator, a liquid storage tank, a balance valve, a steam turbine, an generator connected to the steam turbine, a second condenser, a heat utilization device connected to the second condenser, a pressurizing pump connected to the second condenser, and relevant linkage valve assemblies. The system controls a flow direction and a flow rate after heat pipe steam is extracted from the ground through the steam pump and the regulating valves on the refrigeration side and the power generation side, so as to select the refrigeration/electric heating single-mode heat utilization or adjust flow distribution during refrigeration/electric heating dual-mode combined use.

A heat pump system and a method for implementing efficient evaporation by using a geothermal well are provided. The system includes a stepped underground evaporator, a compressor, a condenser, a liquid storage tank, and a throttle. The underground evaporator includes an inner pipe and an outer pipe. The inner pipe is designed into a multi-section structure. Each section includes a gas guiding pipeline, a baffle plate, and a seepage hole. Under the action of the structure, a liquid working medium flowing into the underground evaporator flows downwards along an inner wall of the outer pipe, and absorbs heat from an underground rock mass and gasifies into a gas working medium; and the gas working medium flows upwards to ground. Compared with the prior art, neither gas-liquid re-entrainment nor a liquid accumulation effect can occur in the underground evaporator designed according to the system and method.

A borehole is bored to a borehole target depth in a site and a geothermal heat exchanger is inserted into and then secured in the borehole at the desired depth. Once the heat exchanger has been secured in the borehole, the heat exchanger has a closed distal end and an open proximal end and has at least one fluid path between the closed distal end and the open proximal end, with installation fluid disposed in the fluid path(s). After securing the heat exchanger in the borehole and before excavation of a portion of the site immediately surrounding the borehole, the heat exchanger is temporarily sealed by installing, through the open proximal end, at least one respective internal seal in each fluid path. For each fluid path, the internal seal(s) will be disposed below a respective notional subgrade depth and excavation of the site immediately surrounding the borehole can proceed.

A method includes flowing, in a closed loop geothermal well residing in a target subterranean zone, a first heat transfer working fluid and flowing, in the geothermal well, a second working fluid from the surface inlet to the downhole location of the geothermal well. The second working fluid resides upstream of the first heat transfer working fluid. The second working fluid includes a fluid density greater than a fluid density of the first heat transfer working fluid. The method also includes circulating, in the geothermal well, the second working fluid pushing, with the second working fluid, the first heat transfer working fluid toward a surface outlet of the geothermal well. The method also includes collecting energy from the mobilized first heat transfer working fluid received at the surface outlet of the geothermal well.

A method includes flowing, in a closed loop geothermal well residing in a target subterranean zone, a first heat transfer working fluid and flowing, in the geothermal well, a second working fluid from the surface inlet to the downhole location of the geothermal well. The second working fluid resides upstream of the first heat transfer working fluid. The second working fluid includes a fluid density greater than a fluid density of the first heat transfer working fluid. The method also includes circulating, in the geothermal well, the second working fluid pushing, with the second working fluid, the first heat transfer working fluid toward a surface outlet of the geothermal well. The method also includes collecting energy from the mobilized first heat transfer working fluid received at the surface outlet of the geothermal well.

The present disclosure relates to an enhanced thermal syphoning system, comprising a first well and a second well extending though a permeable geological layer, each well having: an inlet channel to introduce a fluid into the well and an inlet valve to control an inlet fluid flow rate into the inlet channel; an outlet channel to draw geologically heated fluid from the well and an outlet valve to control an outlet fluid flow rate from the outlet channel; and an opening in the inlet channel adjacent the permeable geological layer wherein fluid in the inlet channel of the first well and the inlet channel of the second well is communicated therebetween via the permeable geological layer, the fluid entering and exiting the inlet channels through the openings therein, such that each inlet and each outlet valve can be adjusted to vary a flow volume of the fluid between the first well and the second well to thereby control a temperature of the heated fluid drawn from each well. The plurality of wells within the system generates fluid movement along and around outer casings of the plurality of wells to improve a heating effect of the wells and to control fluid flow through the wells. The plurality of wells may be configured in a series of adjacent wells or in a series of patterned or nested wells.

The present disclosure relates to an enhanced thermal syphoning system, comprising a first well and a second well extending though a permeable geological layer, each well having: an inlet channel to introduce a fluid into the well and an inlet valve to control an inlet fluid flow rate into the inlet channel; an outlet channel to draw geologically heated fluid from the well and an outlet valve to control an outlet fluid flow rate from the outlet channel; and an opening in the inlet channel adjacent the permeable geological layer wherein fluid in the inlet channel of the first well and the inlet channel of the second well is communicated therebetween via the permeable geological layer, the fluid entering and exiting the inlet channels through the openings therein, such that each inlet and each outlet valve can be adjusted to vary a flow volume of the fluid between the first well and the second well to thereby control a temperature of the heated fluid drawn from each well. The plurality of wells within the system generates fluid movement along and around outer casings of the plurality of wells to improve a heating effect of the wells and to control fluid flow through the wells. The plurality of wells may be configured in a series of adjacent wells or in a series of patterned or nested wells.