Abstract: The present invention discloses a method for determining a content of lost gas in a shale gas content test. The method includes: acquiring a shale core and recording the time required for acquiring the shale core; carrying out a desorption experiment on the shale core to obtain desorption data; acquiring a fitting objective function; fitting the desorption data by using the fitting objective function to obtain fitted desorption data; determining fitting parameters according to the desorption data and the fitted desorption data; correcting the time required for acquiring the shale core according to the fitting parameters; and obtaining the content of lost gas according to the fitting parameters and the corrected time required for acquiring the shale core. The present invention can improve the determining precision of the content of the lost gas.

Abstract: The present invention provides an enhanced oil recovery method by nanofluid-assisted CO2 huff-n-puff. A nanofluid is injected into an injection well in an oil reservoir formation having hydrophilic wetting characteristics, and soaking is performed; in the soaking stage, after the nanofluid tends to replace crude oil to occupy dead-ends of fractures and pores, and liquid CO2 is injected; and in the process of production, CO2 originally dissolved in the formation fluid reaches a supersaturated state. As a result, CO2 preferentially nucleates at the nanofluid side to generate CO2 bubbles, grows and expands with the continuous reduction of formation pressure, and pushes crude oil near the dead-ends of fractures and pores to move outward, thereby improving the recovery efficiency.

Abstract: A method and a system for manufacturing a heat exchanger for supercritical pressure fluid are provided. The manufacturing method includes: obtaining boundary conditions of the heat exchanger, adjusting a preliminary framework of the heat exchanger, dividing each of fluid passages along a fluid flow direction and establishing a thermal equilibrium control model, constructing a machine heat transfer model in combination with a Gaussian regression process and a Cokriging method based on the thermal equilibrium control model, determining on-way thermal parameters about the working fluids flowing and transferring heat, determining a heat transfer area according to the on-way thermal parameters, and determining whether the heat transfer area meets a target heat transfer area. If the heat transfer area meets the target heat transfer area the heat exchanger is manufactured according to the preliminary framework of the heat exchanger.

Abstract: The present invention provides an enhanced oil recovery method by nanofluid-assisted CO2 huff-n-puff. A nanofluid is injected into an injection well in an oil reservoir formation having hydrophilic wetting characteristics, and soaking is performed; in the soaking stage, after the nanofluid tends to replace crude oil to occupy dead-ends of fractures and pores, and liquid CO2 is injected; and in the process of production, CO2 originally dissolved in the formation fluid reaches a supersaturated state. As a result, CO2 preferentially nucleates at the nanofluid side to generate CO2 bubbles, grows and expands with the continuous reduction of formation pressure, and pushes crude oil near the dead-ends of fractures and pores to move outward, thereby improving the recovery efficiency.

Abstract: The present invention discloses a method for determining a content of lost gas in a shale gas content test. The method includes: acquiring a shale core and recording the time required for acquiring the shale core; carrying out a desorption experiment on the shale core to obtain desorption data; acquiring a fitting objective function; fitting the desorption data by using the fitting objective function to obtain fitted desorption data; determining fitting parameters according to the desorption data and the fitted desorption data; correcting the time required for acquiring the shale core according to the fitting parameters; and obtaining the content of lost gas according to the fitting parameters and the corrected time required for acquiring the shale core. The present invention can improve the determining precision of the content of the lost gas.

Abstract: A combined power generation system based on geothermal energy and solar energy and a power generation method thereof are provided. The system includes: at least three injection wells; at least three production wells; at least three connected paths in a reservoir connected with gas outlets of the at least three injection wells and gas inlets of the at least three production wells; at least three geothermal turbines having gas inlets connected with gas outlets of the at least three production wells; a gas cooler; a first regenerator having a high-pressure gas inlet connected with a gas outlet of the upmost production well; a second regenerator having a high-pressure gas inlet connected with one geothermal turbine; a solar receiver having a gas inlet connected with the second regenerator; and a solar turbine having a gas inlet connected with the solar receiver and a gas outlet connected with the second regenerator.

Abstract: A process for treating waste from a pithead power plant and sequestrating carbon dioxide discharged therefrom is provided. A mixed material of solid waste from the power plant, cement and a mixing liquid is filled into a depleted coal mine and compacted. A hydrating liquid is then injected into the filler after compaction to cause hydration. After that, carbon dioxide discharged from the power plant is injected to mineralize the carbon dioxide, thereby achieving carbon dioxide sequestration and reinforcement of the depleted coal mine. The invention utilizes abundant basic oxides present in the solid waste, and the fact that calcium hydroxide and tobermorite present in the hydrated cement chemically react with the injected carbon dioxide to produce stable carbonates in solid, and thus simultaneously achieves carbon dioxide sequestration, treatment of solid waste, and reinforcement of a depleted coal mine.

Abstract: A combined power generation system based on geothermal energy and solar energy and a power generation method thereof are provided. The system includes: at least three injection wells; at least three production wells; at least three connected paths in a reservoir connected with gas outlets of the at least three injection wells and gas inlets of the at least three production wells; at least three geothermal turbines having gas inlets connected with gas outlets of the at least three production wells; a gas cooler; a first regenerator having a high-pressure gas inlet connected with a gas outlet of the upmost production well; a second regenerator having a high-pressure gas inlet connected with one geothermal turbine; a solar receiver having a gas inlet connected with the second regenerator; and a solar turbine having a gas inlet connected with the solar receiver and a gas outlet connected with the second regenerator.