A scale suppression apparatus capable of suppressing in a low-priced manner the generation of silica-based scale and calcium-based scale in the influent water containing at least a silica component and a calcium component, a geothermal power generation system using the same, and a scale suppression method are provided. The scale suppression apparatus includes a chelating agent and alkaline agent addition unit injecting liquid containing a chelating agent and an alkaline agent into a pipe arrangement through which influent water such as geothermal water or the like flows, and a controller controlling a pump and a valve of the chelating agent and alkaline agent addition unit. The controller controls the injection of the chelating agent and the alkaline agent and stops of the injection based on the signal output from a scale detection unit for detecting a precipitation state of the scale.

Several embodiments include a method of computing a phase composition ratio of a two-phase mixture in a pipe. For example, the phase composition ratio is a void fraction or a dryness fraction. The two-phase mixture can have one or more material substances that do not travel as a whole (e.g., at least two of solid phase, liquid phase, and gaseous phase or two liquid materials of different densities that do not mix). A load cell can measure, continuously, weight of the pipe and content of the pipe. Then, a computing system or a circuit can compute, continuously, a moving average of the continuously measured weight. The computing system or the circuit can compute a change in the phase composition ratio of the two-phase mixture based on the computed moving average.

The present invention relates to a geothermal energy extraction subterranean system for extracting heat from a subterranean formation, comprising an injection well comprising a first well tubular metal structure arranged in a first borehole providing a first annulus therebetween and extending from surface into the subterranean formation and being configured to inject a working fluid out through a first injection opening into a production area defined in the subterranean formation and thereby generating a heated working fluid, and a first production well comprising a second well tubular metal structure arranged in a second borehole providing a second annulus therebetween and extending from surface into the subterranean formation into the production area and extracting the heated working fluid through a first production opening, wherein the first well tubular metal structure of the injection well comprises a first annular barrier and a second annular barrier configured to expand in the first annulus to abut a wall of the first borehole to isolate a production zone in the production area, each annular barrier comprising a tubular metal part mounted as part of the first well tubular metal structure, the tubular metal part having a first expansion opening and an outer face, an expandable metal sleeve surrounding the tubular metal part and having an inner face facing the tubular metal part and an outer face facing the wall of the borehole, each end of the expandable metal sleeve being connected with the tubular metal part, and an annular space between the inner face of the expandable metal sleeve and the tubular metal part, the expandable metal sleeve being expanded to abut a wall of the first borehole by entering pressurised fluid into the annular space through the first expansion opening, the first injection opening being arranged in the first well tubular metal structure between the first annular barrier and the second annular barrier, and the first production zone being arranged between the first well tubular metal structure and the second well tubular metal structure so that the heated working fluid is extracted in the second well tubular metal structure through the first production opening. The present invention furthermore relates to a geothermal energy extraction subterranean method for extracting heat from a subterranean formation by means of the geothermal energy extraction subterranean system according to the present invention.

A method for extracting geothermal energy from a geothermal reservoir formation. A production well is used to extract brine from the reservoir formation. At least one of nitrogen (N.sub.2) and carbon dioxide (CO.sub.2) may be used to form a supplemental working fluid which may be injected into a supplemental working fluid injection well. The supplemental working fluid may be used to augment a pressure of the reservoir formation, to thus drive a flow of the brine out from the reservoir formation.

The present disclosure relates to techniques for extracting heat energy from geothermal briny fluid. A briny fluid can be extracted from a geothermal production well and delivered to a heat exchanger. The heat exchanger can receive the briny fluid and transfer heat energy from the briny fluid to a molten salt. The molten salt can be pumped to a molten salt storage tank that can serve as energy storage. The briny fluid can be returned to a geothermal source via the production well. The briny fluid can remain in a closed-loop system, apart from the molten salt, from extraction through return to the geothermal production well.

The present disclosure relates to techniques for extracting heat energy from geothermal briny fluid. A briny fluid can be extracted from a geothermal production well and delivered to a heat exchanger. The heat exchanger can receive the briny fluid and transfer heat energy from the briny fluid to a molten salt. The molten salt can be pumped to a molten salt storage tank that can serve as energy storage. The briny fluid can be returned to a geothermal source via the production well. The briny fluid can remain in a closed-loop system, apart from the molten salt, from extraction through return to the geothermal production well.

The present disclosure is directed to systems, methods and tools that measure ionic concentrations and downhole enthalpy of a flowing geothermal fluid in real-time at high-temperature and pressure. The systems, methods and tools include measuring the concentration of selected naturally occurring ions found in the liquid phase of the geothermal fluid throughout the wellbore using novel electrochemical sensor technologies. The change in liquid-phase ion concentration will be used to calculate the proportion of liquid to steam and allow for accurate enthalpy measurements. The techniques and technologies described here can be applied to any application of electrochemical sensing in extreme environments.

The present disclosure is directed to systems, methods and tools that measure ionic concentrations and downhole enthalpy of a flowing geothermal fluid in real-time at high-temperature and pressure. The systems, methods and tools include measuring the concentration of selected naturally occurring ions found in the liquid phase of the geothermal fluid throughout the wellbore using novel electrochemical sensor technologies. The change in liquid-phase ion concentration will be used to calculate the proportion of liquid to steam and allow for accurate enthalpy measurements. The techniques and technologies described here can be applied to any application of electrochemical sensing in extreme environments.

The present disclosure relates to a system for storing and time shifting at least one of excess electrical power from an electrical power grid, excess electrical power from the power plant itself, or heat from a heat generating source, in the form of pressure and heat, for future use in assisting with a production of electricity. An oxy-combustion furnace is powered by a combustible fuel source, plus excess electricity, during a charge operation to heat a reservoir system containing a quantity of a thermal storage medium. During a discharge operation, a discharge subsystem has a heat exchanger which receives heated CO.sub.2 from the reservoir system and uses this to heat a quantity of high-pressure, supercritical CO.sub.2 (sCO.sub.2) to form very-high-temperature, high-pressure sCO.sub.2 at a first output thereof. The very-high-temperature, high-pressure sCO.sub.2 is used to drive a Brayton-cycle turbine, which generates electricity at a first output thereof for transmission to a power grid. The Brayton-cycle turbine also outputs a quantity of sCO.sub.2 which is reduced in temperature and pressure to a heat recuperator subsystem. The heat recuperator subsystem circulates the sCO.sub.2 and re-heats and re-pressurizes the sCO.sub.2 before feeding it back to the heat exchanger to be even further reheated, and then output to the Brayton-cycle turbine as a new quantity of very-high-temperature, high-pressure sCO.sub.2, to assist in powering the Brayton-cycle turbine.

The present disclosure relates to a system for storing and time shifting at least one of excess electrical power from an electrical power grid, excess electrical power from the power plant itself, or heat from a heat generating source, in the form of pressure and heat, for future use in assisting with a production of electricity. An oxy-combustion furnace is powered by a combustible fuel source, plus excess electricity, during a charge operation to heat a reservoir system containing a quantity of a thermal storage medium. During a discharge operation, a discharge subsystem has a heat exchanger which receives heated CO.sub.2 from the reservoir system and uses this to heat a quantity of high-pressure, supercritical CO.sub.2 (sCO.sub.2) to form very-high-temperature, high-pressure sCO.sub.2 at a first output thereof. The very-high-temperature, high-pressure sCO.sub.2 is used to drive a Brayton-cycle turbine, which generates electricity at a first output thereof for transmission to a power grid. The Brayton-cycle turbine also outputs a quantity of sCO.sub.2 which is reduced in temperature and pressure to a heat recuperator subsystem. The heat recuperator subsystem circulates the sCO.sub.2 and re-heats and re-pressurizes the sCO.sub.2 before feeding it back to the heat exchanger to be even further reheated, and then output to the Brayton-cycle turbine as a new quantity of very-high-temperature, high-pressure sCO.sub.2, to assist in powering the Brayton-cycle turbine.