Methods, apparatus, equipment and storage media for analyzing the thermal structure of the lithosphere

Abstract

This application discloses a method, apparatus, equipment, and storage medium for analyzing the thermal structure of the lithosphere, relating to the field of geothermal energy analysis technology. The method includes: acquiring rock information of the current region and constructing a current lithosphere model, the current lithosphere model consisting of several layers of lithological units; determining the surface geothermal heat flow value and the location of the lithosphere floor corresponding to the current lithosphere model based on the rock information and preset temperature change rules; determining the layered heat flow values ​​corresponding to each lithological unit above the lithosphere floor based on the rock information, and obtaining the lithosphere heat flow value based on each layered heat flow value; and combining the surface geothermal heat flow value and the lithosphere heat flow value to determine heat flow ratio parameters as the analysis result of the lithosphere thermal structure of the current region. This application obtains heat flow ratio parameters by performing layered modeling of the lithosphere, thereby achieving accurate quantification of the lithosphere thermal structure from the perspective of heat source properties and heat transfer mechanisms, and improving the reliability of the analysis results.

Description

Technical Field

[0001] This application relates to the field of geothermal energy analysis technology, and in particular to a method, apparatus, equipment and storage medium for analyzing the thermal structure of the lithosphere. Background Technology

[0002] Regional thermal structure is a key factor controlling the formation and distribution of underground energy and mineral resources, and has a decisive influence on the occurrence of geothermal resources, oil and gas reservoirs, natural hydrogen, and other energy sources, as well as mineral deposits such as metals and gemstones. Currently, resources with economic development value are mainly concentrated in the shallow crust, and the thermal state of the shallow strata is directly regulated by deep thermodynamic processes (such as plate subduction, mantle convection, and lithospheric thinning). The lithosphere is the outermost rigid solid shell of the Earth, serving as an insulating layer for the transfer of heat from the Earth's interior to the surface. Its interaction with the asthenosphere and lower mantle is crucial for understanding Earth's thermodynamics. Therefore, thermal structure analysis can be conducted based on the Earth's heat transfer pathways from the interior to the exterior, using the asthenosphere and lithosphere as a framework.

[0003] However, since the lithosphere consists of the crust and the uppermost part of the upper mantle (lithospheric mantle), and the asthenosphere is also located in the upper mantle, existing lithospheric thermal structures refer to the distribution ratio and compositional relationship of heat flow between the crust and mantle in a region. It is difficult to clearly distinguish crustal heat flow, lithospheric mantle heat flow, and asthenosphere heat flow from the perspective of heat source properties and heat transfer mechanisms. This leads to overlapping and confusion of crust-mantle heat flow, which in turn affects the reliability of analytical results determined based on heat flow distribution. Summary of the Invention

[0004] The main objective of this application is to provide a method, apparatus, device, and storage medium for analyzing the thermal structure of the lithosphere, aiming to solve the technical problem of low reliability of existing analysis results determined based on heat flow distribution.

[0005] To achieve the above objectives, this application proposes a method for analyzing the thermal structure of the lithosphere, the method comprising:

[0006] Obtain rock information for the current region and construct a current lithosphere model based on the rock information. The current lithosphere model consists of several layers of lithological units.

[0007] Based on the rock information and the preset temperature change rules, determine the surface geothermal heat flow value and the location of the bottom boundary of the lithosphere corresponding to the current lithosphere model;

[0008] Based on the rock information, determine the hierarchical heat flow value corresponding to each lithological unit located above the bottom boundary of the lithosphere, and obtain the lithosphere heat flow value based on each hierarchical heat flow value;

[0009] The heat flow ratio parameters are determined by combining the Earth's surface heat flow value and the lithosphere heat flow value, and these heat flow ratio parameters are used as the results of the lithosphere thermal structure analysis for the current region.

[0010] In one embodiment, the rock information includes: vertical rock category information; the step of acquiring the rock information of the current region and constructing the current lithosphere model based on the rock information includes:

[0011] Initialize the lithosphere hierarchy model and each lithological unit based on the standard lithosphere structure;

[0012] Obtain vertical rock category information for the current area, wherein the vertical rock category information is obtained from rock surveying of the current area;

[0013] Based on the vertical rock category information, the rock category corresponding to each lithological unit is determined, and the lithosphere hierarchical model is labeled based on the rock category correspondence to obtain the current lithosphere model.

[0014] In one embodiment, the rock information further includes: measured temperature data. The step of determining the surface geothermal flow value and the location of the lithosphere floor corresponding to the current lithosphere model based on the rock information and preset temperature change rules includes:

[0015] Based on the measured temperature data and in accordance with the preset temperature change rules, the average geothermal gradient corresponding to the current lithosphere model is determined;

[0016] Based on the average geothermal gradient and the thermal conductivity information of each lithological unit, the surface geothermal heat flow value and the temperature data of each lithological unit are obtained.

[0017] Geothermal distribution curves are generated based on the temperature data of each lithological unit, and the location of the lithosphere floor is obtained based on the geothermal distribution curves.

[0018] In one embodiment, the step of obtaining the surface geothermal heat flow value and the temperature data of each lithological unit based on the average geothermal gradient and the thermal conductivity information of each lithological unit includes:

[0019] The thermal conductivity information of each lithological unit is obtained, and the harmonic thermal conductivity is obtained based on the thermal conductivity information. The thermal conductivity information is the thermal conductivity measurement value of each rock type under the corresponding lithological unit conditions.

[0020] The Earth's surface heat flow value is determined based on the average geothermal gradient and the harmonic thermal conductivity.

[0021] The heat generation rate information of each lithological unit is obtained, and the temperature data of each lithological unit is determined layer by layer based on the heat generation rate information, the thermal conductivity information, and the surface geothermal heat flow value.

[0022] In one embodiment, the step of generating geothermal distribution curves based on the temperature data of each lithological unit, and obtaining the location of the lithosphere floor based on the geothermal distribution curves, includes:

[0023] Geothermal distribution curves are generated based on the temperature data of each lithological unit;

[0024] The intersection point analysis is performed between the geothermal distribution curve and at least one standard reference line to obtain the target intersection point position, and the corresponding value of the target intersection point position is determined as the position of the bottom boundary of the lithosphere. The standard reference line includes: the solid phase line of the rock and the mantle adiabatic line.

[0025] In one embodiment, the step of determining the hierarchical heat flow value corresponding to each lithological unit located above the bottom boundary of the lithosphere based on the rock information, and obtaining the lithosphere heat flow value based on each hierarchical heat flow value, includes:

[0026] The rock mass thickness of each lithological unit is determined based on the vertical rock type information;

[0027] The heat generation rate information of each lithological unit is obtained, and the hierarchical heat flux value of each lithological unit is obtained based on the heat generation rate information and the corresponding rock mass thickness.

[0028] The heat flow values ​​of the lithosphere are obtained by summing the heat flow values ​​of each lithological unit located above the bottom boundary of the lithosphere.

[0029] In one embodiment, the step of determining the heat flow ratio parameter by combining the Earth's surface geothermal heat flow value and the lithosphere heat flow value includes:

[0030] Subtracting the lithospheric heat flow value from the Earth's surface heat flow value yields the asthenospheric heat flow value.

[0031] The heat flux ratio coefficient is obtained by dividing the lithospheric heat flux value by the asthenospheric heat flux value.

[0032] Furthermore, to achieve the above objectives, this application also proposes a lithosphere thermal structure analysis device, the device comprising:

[0033] The structural partitioning module is used to acquire rock information of the current region and construct a current lithosphere model based on the rock information. The current lithosphere model consists of several layers of lithological units.

[0034] The first heat flow calculation module is used to determine the surface geothermal heat flow value and the location of the bottom boundary of the lithosphere corresponding to the current lithosphere model based on the rock information and preset temperature change rules.

[0035] The second heat flow calculation module is used to determine the hierarchical heat flow value corresponding to each lithological unit located above the bottom boundary of the lithosphere based on the rock information, and to obtain the lithosphere heat flow value based on each hierarchical heat flow value.

[0036] The quantitative analysis module is used to determine the heat flow ratio parameters by combining the Earth's surface heat flow value and the lithosphere heat flow value, and to determine the heat flow ratio parameters as the lithosphere thermal structure analysis results of the current region.

[0037] In addition, to achieve the above objectives, this application also proposes a lithospheric thermal structure analysis device, the device comprising: a memory, a processor, and a lithospheric thermal structure analysis program stored in the memory and executable on the processor, the lithospheric thermal structure analysis program being configured to implement the steps of the lithospheric thermal structure analysis method as described above.

[0038] In addition, to achieve the above objectives, this application also proposes a storage medium, which is a computer-readable storage medium, storing a lithosphere thermal structure analysis program, which, when executed by a processor, implements the steps of the lithosphere thermal structure analysis method as described above.

[0039] This application discloses a method for analyzing the thermal structure of the lithosphere, comprising: acquiring rock information of the current region and constructing a current lithosphere model based on the rock information, wherein the current lithosphere model consists of several layers of lithological units; determining the geothermal heat flow value and the position of the lithosphere floor corresponding to the current lithosphere model according to the rock information and a preset temperature change rule; determining the hierarchical heat flow value corresponding to each lithological unit above the lithosphere floor based on the rock information, and obtaining the lithosphere heat flow value based on the hierarchical heat flow value; determining the heat flow ratio parameter by combining the geothermal heat flow value and the lithosphere heat flow value, and determining the heat flow ratio parameter as the result of the lithosphere thermal structure analysis of the current region.

[0040] This application enables precise quantification of the thermal structure of the lithosphere through layered modeling and refined analysis. Specifically, it organically combines the heat flux values ​​of the asthenosphere and the lithosphere through heat flux ratio parameters, providing a comprehensive quantitative index for the analysis of the thermal structure of the lithosphere, thereby improving the reliability of the analysis results. Attached Figure Description

[0041] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with this application and, together with the description, serve to explain the principles of this application.

[0042] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, for ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0043] Figure 1 This is a flowchart illustrating the first embodiment of the lithosphere thermal structure analysis method of this application;

[0044] Figure 2 This is a flowchart illustrating the second embodiment of the lithosphere thermal structure analysis method of this application;

[0045] Figure 3 This is a flowchart illustrating the third embodiment of the lithosphere thermal structure analysis method of this application;

[0046] Figure 4 This is a schematic diagram of the module structure of the first embodiment of the lithosphere thermal structure analysis device of this application;

[0047] Figure 5 This is a schematic diagram of the lithospheric thermal structure analysis device in the embodiments of this application. Detailed Implementation

[0048] It should be understood that the specific embodiments described herein are merely illustrative of the technical solutions of this application and are not intended to limit this application.

[0049] To better understand the technical solution of this application, a detailed description will be provided below in conjunction with the accompanying drawings and specific implementation methods.

[0050] This application provides a method for analyzing the thermal structure of the lithosphere, referring to... Figure 1 , Figure 1 This is a flowchart illustrating the first embodiment of the lithosphere thermal structure analysis method of this application. In this embodiment, the method includes steps S10 to S40:

[0051] Step S10: Obtain rock information of the current area and construct a current lithosphere model based on the rock information. The current lithosphere model consists of several layers of lithological units.

[0052] It should be noted that the execution subject of the method in this embodiment can be a computing electronic device with data processing, network communication, and program execution capabilities, such as a mobile phone, personal computer, or lithosphere thermal structure analyzer. Here, an example is taken using a lithosphere thermal structure analysis device (hereinafter referred to as "analysis device") to illustrate this embodiment and the following embodiments.

[0053] It should be understood that the current area is the area where lithospheric thermal structure analysis is required. The rock information of the current area can include vertical rock category information obtained by using methods such as geological surveys, drilling sampling, and geophysical exploration to conduct vertical structural surveys of the area, such as the rock categories collected, the thickness of each rock category, and the distribution range of each rock category.

[0054] Next, based on the acquired rock information, the lithosphere can be divided into several lithological units. Each lithological unit represents a rock layer with a certain thickness and specific lithology. For example, a simple lithosphere model might include sedimentary rock layers, granite layers, metamorphic rock layers, etc., starting from the Earth's surface. The parameters of each lithological unit, such as thickness and rock type, are set according to the actual acquired rock information, thereby constructing a model that can reflect the basic structure of the lithosphere in the current region.

[0055] To illustrate the construction process of the current lithosphere model, step S10 may include: steps S101~S103:

[0056] Step S101: Initialize the lithosphere hierarchical model and each lithological unit based on the standard lithosphere structure.

[0057] It should be understood that this standard lithospheric structure can be a vertical structural hierarchy from the Earth's surface to the bottom of the lithospheric mantle, obtained based on historical experience. Analytical equipment can directly use this standard lithospheric structure as the initial lithospheric hierarchical model. For example, the lithological units obtained from top to bottom can be: sedimentary layer, crystalline basement, upper crust, lower crust, and lithospheric mantle.

[0058] Step S102: Obtain vertical rock category information for the current area, wherein the vertical rock category information is obtained by rock surveying the current area.

[0059] Step S103: Determine the rock category corresponding to each lithological unit based on the vertical rock category information, and label the lithosphere hierarchical model based on the rock category correspondence to obtain the current lithosphere model.

[0060] It should be understood that, since the vertical depth that can be collected by surveying methods is limited, the current area can be divided into shallow and deep strata in the vertical direction, and the shallow strata can be identified with high precision, while the deep strata can be predicted with high precision.

[0061] When conducting high-precision identification of shallow strata, if the current area is suitable for drilling, direct exploration techniques can be used to drill and obtain core samples. Through core testing and analysis (such as isotope dating, geochemical analysis, and mineral identification) and / or well logging, the precise dating and lithology of the strata can be determined. In areas lacking drilling data, geophysical methods such as gravity, magnetics, electrical resistivity tomography, and seismic exploration can be comprehensively utilized. By combining single or multiple methods in inversion, geological structural units and their spatial distribution characteristics can be effectively identified.

[0062] When making high-precision predictions of deep strata, current drilling technology limits the direct acquisition of physical data on strata deeper than 10 km. Therefore, indirect high-precision analytical or collaborative inversion techniques can be used to predict deep vertical structures. The indirect high-precision analytical techniques employed can include seismic exploration, electromagnetic exploration, and gravity exploration.

[0063] Seismic exploration technology involves artificially generating elastic waves. When these elastic waves propagate through underground strata, they undergo reflection and refraction when they encounter different rock interfaces or structures. By analyzing and processing these elastic wave propagation characteristics (such as the travel time, amplitude, and frequency of reflected waves), the location of interfaces, structural morphology, and elastic properties of rocks in deep strata can be inferred.

[0064] Electromagnetic exploration technology can detect fluid-bearing layers based on differences in the electrical properties of rocks. When fluid-bearing layers exist within underground rocks, the significant difference in conductivity between the fluid and the surrounding rock will result in a significant response to electromagnetic fields. By measuring the characteristics of changes in the electromagnetic field, the location and distribution range of these fluid-bearing layers can be identified.

[0065] Gravity exploration technology infers the density distribution of underground rocks by measuring anomalous changes in the Earth's gravitational field. Different types of rocks have different densities, and changes in the composition of deep materials cause anomalies in the gravitational field. By analyzing gravity anomaly data, the density structure of underground rocks can be deduced, thereby inferring changes in the material composition of deep strata and the distribution of geological structural units.

[0066] By performing joint inversion based on the above technologies, it is possible to fuse multi-physics data and comprehensively utilize various geophysical information for mutual supplementation and verification, thereby improving the reliability and resolution of deep structure imaging.

[0067] In practice, by performing high-precision identification of shallow strata and high-precision prediction of deep strata, the rock categories corresponding to each lithological unit can be obtained and the model can be labeled: sedimentary layer (sedimentary rocks), crystalline basement (metamorphic rocks / igneous rocks), upper crust (mainly granitic / basaltic) and lower crust (mainly granulite facies / gabbro), and lithospheric mantle (mainly peridotite).

[0068] It should be understood that representative samples from each lithological unit can also be collected separately to measure the thermal properties of each lithological unit, including density, thermal conductivity, and heat generation rate. For shallow rock masses with drilling conditions, complete core samples can be obtained; while for shallow and deep rocks without drilling conditions, fresh samples from surface outcrops of the same lithology as the vertical structure can be collected through field exploration.

[0069] Density testing can be performed using methods such as the helium hydrometer method or the Archimedes method to test the density of rock samples.

[0070] Thermal conductivity testing can be performed using methods such as the moving heat source method, laser flash method, transient plate heat source method, and probe method. In order to obtain the in-situ thermal conductivity of underground samples, the collected rock samples can be saturated with water, pressurized, and heated to simulate the in-situ conditions for testing. If pressurization and heating conditions are not available, empirical formulas proposed by predecessors can be used for correction.

[0071] The calculation process for the heat generation rate can be as follows: The main radioactive decay elements in the rock are tested using inductively coupled plasma mass spectrometry (ICP-MS). 238 U、 232 Th and 40 The K content is used to calculate the heat generation rate using an empirical formula: A = 0.01 (9.52C U +2.56C Th +3.48C K In the formula, A is the heat generation rate, and the unit is... W / m3; Density, unit: g / cm³ 3 C U The uranium content in the rock. g / g; C Th Thorium content in rocks, in units of g / g; C K The value represents the potassium content in the rock, expressed in percent.

[0072] Based on the measurement results of the above thermal property parameters, the thermal property parameters corresponding to each level unit in the lithosphere hierarchical model can be labeled respectively, and the current lithosphere model can be obtained after labeling.

[0073] It should also be noted that, since the traditional standard definition of the lithosphere includes the entire crust and the top of the upper mantle, the bottom layer of the current lithosphere model determined based on survey data may not necessarily be the boundary between the top of the upper mantle and the asthenosphere as defined in the standard definition. Therefore, this current lithosphere model can be regarded as a rough model of the lithosphere in the current region.

[0074] Step S20: Based on the rock information and the preset temperature change rules, determine the surface geothermal flow value and the location of the bottom boundary of the lithosphere corresponding to the current lithosphere model.

[0075] It should be noted that the preset temperature change rule can be a geothermal gradient change rule determined based on geothermal theory and empirical formulas. The geothermal gradient is the rate of temperature change with depth. Under normal circumstances, the geothermal gradient has a certain average value and range of variation. Different rock types may have different geothermal gradient characteristics, and the heat generation rate generated by the decay of radioactive elements in the rock will also affect the temperature distribution.

[0076] Geothermal heat flow is equal to the sum of crustal heat flow and mantle heat flow. It reflects the amount of heat transferred from the Earth's interior through the lithosphere to the surface and is one of the important parameters for analyzing the thermal structure of the lithosphere. Based on the rules of geothermal gradient variation and combined with rock information (such as the thermal conductivity and heat generation rate of rocks), the value of geothermal heat flow can be determined. Using mathematical models such as the heat conduction equation, the temperature distribution downwards from the Earth's surface can be calculated.

[0077] In practice, the measured temperature data of the near-surface isothermal zone to a portion of the underground lithological units can be obtained first, and then the average geothermal gradient can be calculated using the geothermal gradient variation rules. The harmonic thermal conductivity of the lithosphere in this part can be estimated based on the thermal conductivity of each rock type measured above. Finally, the geothermal heat flow value of the Earth's surface can be calculated based on the average geothermal gradient and harmonic thermal conductivity of this part.

[0078] It should also be noted that, since the vertical depth collected by the surveying methods is uncertain, in order to conduct thermal structure analysis of the lithosphere from the perspective of heat source and heat transfer mechanism, the position of the bottom boundary of the lithosphere in the current region can be determined first, that is, the boundary between the top of the upper mantle and the asthenosphere in the current region, so as to determine the specific boundary position between the lithosphere and the asthenosphere in the current lithosphere model.

[0079] In practical implementation, the bottom boundary of the lithosphere can be determined when the temperature curve reaches certain conditions (such as the temperature characteristics of the top of the asthenosphere or the temperature at which the rock begins to partially melt). For example, based on the solidus temperature of the rock (the temperature at which the rock begins to melt), the depth corresponding to the temperature reached by the calculated temperature distribution curve is the location of the bottom boundary of the lithosphere.

[0080] Step S30: Determine the hierarchical heat flow value corresponding to each lithological unit located above the bottom boundary of the lithosphere based on the rock information, and obtain the lithosphere heat flow value based on each hierarchical heat flow value.

[0081] It should be noted that in the current lithosphere model, for each lithological unit above the bottom boundary of the lithosphere, the hierarchical heat flow value of each lithological unit can be calculated based on its rock information (such as heat generation rate, thickness, etc.) and temperature distribution.

[0082] The hierarchical heat flow value represents the portion of heat contributed by each lithological unit to the thermal structure of the lithosphere. For example, given the thickness and corresponding heat generation rate of a given lithological unit, the hierarchical heat flow value of that lithological unit can be calculated.

[0083] In practice, the layer-by-layer heat flow values ​​of the lithological units in the current lithosphere model are calculated layer by layer. The calculation range is from the uppermost layer of the current lithosphere model to the bottom boundary of the lithosphere. The heat flow values ​​of each layer are accumulated and summed to obtain the total heat flow generated by the rock exothermic within the lithosphere range as defined in the standard, i.e., the lithosphere heat flow value.

[0084] Step S40: Determine the heat flow ratio parameter by combining the Earth surface heat flow value and the lithosphere heat flow value, and use the heat flow ratio parameter as the result of the lithosphere thermal structure analysis of the current region.

[0085] It should be noted that, in order to accurately distinguish the properties of heat flow by strictly differentiating between conduction-dominated lithospheric heat flow (radioactive heat generation) and convection-dominated asthenospheric heat flow (deep thermal energy), the Earth's surface geothermal flow can be divided into lithospheric heat flow and asthenospheric heat flow.

[0086] It should be understood that the heat flux ratio parameter is a parameter obtained by comparing and analyzing the heat flux values ​​of the lithosphere and the asthenosphere. This parameter can redefine the thermal structure characteristics of the lithosphere from the perspective of heat flux distribution, and compared with the traditional crust-mantle heat flux ratio method, it can more accurately reflect the thermodynamic coupling relationship of the lithosphere-asthenosphere system.

[0087] In practice, the asthenospheric heat flow value can be obtained by subtracting the lithospheric heat flow value from the Earth's surface heat flow value. The asthenospheric heat flow value can then be divided by the asthenospheric heat flow value to obtain the heat flow ratio coefficient, which serves as the analysis result of the lithospheric thermal structure of the current region. This result can be used to assess the thermal state of the lithosphere, its thermal evolution process, and its relationship with tectonic activity. For example, different ranges of heat flow ratio parameters may correspond to different lithospheric types (such as stable continental lithosphere, active lithosphere, etc.) or geological tectonic backgrounds (such as subduction zones, hotspots, etc.), thus providing important reference data for geological research, resource exploration, and other related fields.

[0088] This embodiment establishes a new quantitative analysis method based on the essence of thermodynamics by strictly distinguishing between conduction-dominated lithospheric heat flow (radioactive heat generation) and convection-dominated asthenospheric heat flow (deep thermal energy). Through layered modeling and refined analysis of the lithosphere, it achieves accurate quantification of the lithospheric thermal structure and specifically combines the Earth's surface geothermal heat flow value with the lithospheric heat flow value through heat flow ratio parameters. This provides a comprehensive quantitative index for the analysis of the lithospheric thermal structure, thereby improving the reliability of the analysis results.

[0089] Based on the first embodiment of the present application, in the second embodiment of the present application, the same or similar contents as those in the above embodiment 1 can be referred to the above introduction and will not be described in detail later. Figure 2 , Figure 2 This is a flowchart illustrating the second embodiment of the lithosphere thermal structure analysis method of this application.

[0090] In this embodiment, to specifically illustrate how to determine the Earth's surface geothermal flow value and the bottom boundary of the lithosphere, step S20 includes: steps S201~S203:

[0091] Step S201: Based on the measured temperature data and according to the preset temperature change rules, determine the average geothermal gradient corresponding to the current lithosphere model.

[0092] It should be understood that the aforementioned rock information may also include measured temperature data, which may be temperature data from the near-surface isothermal zone to a portion of the underground lithological unit obtained through direct or indirect measurement.

[0093] For example, temperature can be measured directly in borehole areas by using a thermistor thermometer to perform steady-state temperature measurement and obtain continuous vertical temperature data. Indirect temperature measurement can be used in areas without boreholes by using geophysical exploration (magnetotelluric, seismic wave velocity changes, etc.), geochemical thermometers (SiO2 thermometers, cation thermometers, gas chemical thermometers, isotope thermometers, etc.) or remote sensing (infrared radiation temperature measurement).

[0094] The preset temperature change rule refers to the law governing temperature variation with depth, determined based on geothermal theory and experience. Therefore, after obtaining measured temperature data, the temperature increase can be calculated according to the temperature change rule per hundred meters or kilometers (the temperature abrupt change range can be reduced to the meter level), based on the data volume, thereby calculating the average geothermal gradient from the surface to the bottom of the temperature measurement. Simultaneously, it is determined whether the steady-state temperature measurement curve exhibits a linear change; if a non-linear change exists, the presence of convection must be considered.

[0095] Step S202: Based on the average geothermal gradient and the thermal conductivity information of each lithological unit, obtain the surface geothermal heat flow value and the temperature data of each lithological unit.

[0096] It should be understood that in a topographic structure composed of multiple rock layers, the harmonic thermal conductivity is an average thermal conductivity value obtained by comprehensively considering the thickness and thermal conductivity of each rock layer, and can better reflect the thermal conduction characteristics of the entire stratum. The harmonic average value of the current lithosphere model can be calculated by taking the harmonic average value of the thermal conductivity of each rock type, that is, the sum of the thickness of each layer divided by the corresponding thermal conductivity, and then dividing by the total thickness.

[0097] Understandably, according to Fourier's law of heat conduction, the Earth's surface heat flow equals its thermal conductivity multiplied by its geothermal gradient. This surface heat flow refers to the heat flow from the Earth's interior to its surface, and is equal to the average thermal conductivity from the near-surface isothermal zone to the subsurface portion multiplied by the average geothermal gradient. Therefore, by substituting the calculated harmonic thermal conductivity and average geothermal gradient values, the Earth's surface heat flow can be obtained. This value reflects the amount of heat transferred per unit area from the Earth's interior to its surface.

[0098] It should also be noted that for another part of the current lithosphere model, where there are no corresponding lithological units with measurable temperatures, deep temperatures cannot be directly obtained due to drilling limitations. Therefore, these temperatures can be obtained indirectly through methods such as steady-state equation derivation, geophysical inversion, and mantle xenolith constraints.

[0099] It should be understood that, starting from the Earth's surface, the temperature distribution within each lithological unit can be calculated layer by layer using the Earth's surface heat flow value, combined with the heat generation rate and thermal conductivity information of each lithological unit, according to the heat conduction equation. For example, under steady-state heat conduction conditions, the temperature at the bottom of the current layer can be calculated based on parameters such as the temperature of the bottom boundary of the previous layer, the heat generation rate, thermal conductivity, and thickness of the current layer, and so on, to obtain the temperature data of each lithological unit.

[0100] In addition, temperature can be obtained by using the correlation between seismic wave velocity and temperature proposed by predecessors, by constraining partial melting through electromagnetic methods, by determining the Curie temperature based on the demagnetization temperature of minerals, and by estimating the temperature using empirical formulas through olivine, spinel, and other minerals in mantle xenoliths, thereby obtaining temperature data for each lithological unit.

[0101] In practice, the thermal conductivity information of each lithological unit from the near-surface isothermal zone to the underground part can be obtained first, and the harmonic thermal conductivity can be obtained based on the thermal conductivity information. Then, the geothermal heat flow value can be determined according to the average geothermal gradient and the harmonic thermal conductivity. Finally, the heat generation rate information of each lithological unit can be obtained, and the temperature data of each lithological unit can be determined layer by layer according to the heat generation rate information, thermal conductivity information and geothermal heat flow value.

[0102] Step S203: Generate geothermal distribution curves based on the temperature data of each lithological unit, and obtain the location of the lithosphere floor based on the geothermal distribution curves.

[0103] It should be noted that the lower boundary of the lithosphere is the interface between the lithosphere and the asthenosphere. At this location, the physical and thermodynamic properties of the lithosphere change significantly: the rocks at the lower boundary of the lithosphere are relatively hard, while the materials in the asthenosphere have a certain degree of plasticity and can undergo slow deformation and flow.

[0104] It should be understood that the temperature data of each lithological unit can be arranged in order of depth, and a geothermal distribution curve can be plotted with temperature on the x-axis and depth on the y-axis (or vice versa). This geothermal distribution curve visually demonstrates the trend of underground temperature variation with depth, reflecting the temperature field characteristics within the lithosphere.

[0105] Next, by analyzing the geothermal distribution curve and combining it with the temperature characteristics of the lithosphere's lower boundary (such as the temperature at which the asthenosphere reaches its top or the temperature at which rocks begin to partially melt), the depth corresponding to when the curve reaches that temperature characteristic can be determined, which is the location of the lithosphere's lower boundary. For example, if the temperature at the top of the asthenosphere is known to be approximately a certain value, the depth corresponding to when the geothermal distribution curve reaches or approaches that temperature value is the depth of the lithosphere's lower boundary.

[0106] In practice, the geothermal distribution curve and at least one standard reference line (rock solid phase line or mantle adiabatic line) can be plotted on the same coordinate system. The intersection points between them can be observed and the intersection point analysis can be performed to obtain the target intersection point position. The corresponding value of the target intersection point position is then determined as the position of the bottom boundary of the lithosphere.

[0107] The solidus curve of a rock refers to the temperature curve at which a rock begins to melt under different pressures. It represents the temperature-pressure relationship as a rock transitions from a solid state to a mixed solid-liquid state under specific geological conditions. The solidus curve varies depending on the type of rock (such as granite and basalt). For example, the solidus curve temperature of dry basalt is usually higher than that of basalt containing moisture, because volatiles such as water can lower the melting point of the rock.

[0108] The mantle adiabatic line is a curve showing the temperature change with depth as mantle material rises or sinks adiabatically. An adiabatic process means that the mantle material does not exchange heat with its surroundings; temperature changes are caused solely by its own compression or expansion. The slope of the mantle adiabatic line depends primarily on the physical properties of the mantle material, such as its coefficient of thermal expansion and specific heat capacity. The temperature of a normal mantle adiabatic line increases with depth, but the increase is smaller than that of the geothermal gradient.

[0109] This embodiment, through the rational use of measured temperature data and adherence to preset temperature change rules, scientifically calculates the average geothermal gradient, serving as the basis for subsequent heat flow calculations and thermal structure analysis, thus ensuring the reliability of the foundational data. Furthermore, the method of determining the location of the lithosphere's lower boundary by analyzing the intersection of the generated geothermal distribution curve and the standard reference line provides a clear and objective basis for defining the lithosphere's lower boundary, making the determination of the lithosphere's lower boundary more consistent with actual geological conditions and greatly enhancing the scientific rigor and credibility of the lithosphere's thermal structure analysis results.

[0110] Based on the first and second embodiments of this application, in the third embodiment of this application, the content that is the same as or similar to that in embodiments one and two above can be referred to the above description, and will not be repeated hereafter. Based on this, please refer to... Figure 3 , Figure 3 This is a flowchart illustrating the third embodiment of the lithosphere thermal structure analysis method of this application.

[0111] In this embodiment, to specifically illustrate how to calculate the lithospheric heat flow value after determining the bottom boundary of the lithosphere, step S30 specifically includes: steps S301~S303:

[0112] Step S301: Determine the rock mass thickness of each lithological unit based on the vertical rock category information.

[0113] Step S302: Obtain the heat generation rate information of each lithological unit, and obtain the layered heat flow value of each lithological unit based on the heat generation rate information and the corresponding rock mass thickness.

[0114] It should be understood that, based on the aforementioned vertical rock category information, the rock mass thickness of each lithological unit in the current lithosphere model can be obtained; and based on the aforementioned sample tests of each lithological unit, the heat generation rate measurement value of each lithological unit can be obtained.

[0115] In practical implementation, the hierarchical heat flux value of each lithological unit can be calculated based on the heat generation rate and rock mass thickness. The calculation formula is: Hierarchical heat flux value = Heat generation rate Rock mass thickness.

[0116] Step S303: Sum the hierarchical heat flow values ​​corresponding to each lithological unit located above the bottom boundary of the lithosphere to obtain the lithosphere heat flow value.

[0117] It should be understood that in the current lithosphere model, the lithological units located above the bottom boundary of the lithosphere constitute the lithosphere in the standard definition. The heat flow values ​​of the above-mentioned lithological units can be summed to obtain the heat flow value of the lithosphere, which represents the total heat flow generated by the radioactive heat generation of rocks within the standard lithosphere.

[0118] Furthermore, after obtaining the lithospheric heat flow, the difference between it and the aforementioned surface geothermal heat flow can be determined as the asthenospheric heat flow. Thus, by dividing the lithospheric heat flow by the asthenospheric heat flow, the heat ratio coefficient can be obtained to quantitatively determine the lithospheric thermal structure of the current region.

[0119] Specifically, the thermal saturation ratio reflects the relationship between heat flow at the Earth's surface and in the lithosphere, while the structure of the thermolithospheric sphere influences the shallow geothermal field and the distribution of energy and mineral resources. The thickness and internal structure of the thermolithospheric sphere control the geothermal gradient and heat flow distribution, respectively, and are directly related to the formation mechanism of the thermal saturation ratio. Comprehensive analysis of the thermolithospheric structure, combined with the thermal saturation ratio, can provide a deeper understanding of the shallow thermal state and offer crucial information for the exploration and development of underground energy and mineral resources.

[0120] For example, the thickness of the lithosphere affects the shallow geothermal field and alters the geothermal gradient: when the lithosphere is thinner, the deep heat flow path is shorter, and the geothermal gradient increases; when it is thicker, the path is longer, and the geothermal gradient decreases. This mainly reflects the influence of asthenospheric heat flow, which is closely related to the proportion of asthenospheric heat flow in the heat ratio. The heat ratio can reflect the impact of this thickness difference on the shallow thermal state, helping to understand changes in the geothermal field.

[0121] The thickness and heat generation rate of lithological layers within the lithosphere jointly determine the vertical distribution of heat flow. High heat generation rates or thicker lithological layers significantly increase the contribution of heat flow, leading to increased geothermal temperatures. The heat ratio reflects the relationship between heat flow from the thermolithospheric layer and surface heat flow, and its magnitude is influenced by the internal structure of the thermolithospheric layer. When analyzing the heat ratio, it is necessary to consider the regulation of heat flow by the internal structure to accurately assess the effect of the thermolithospheric layer on the thermal state of shallow strata.

[0122] Furthermore, due to the complex ratio of heat flow between the asthenosphere and the lithosphere under actual geological conditions, regional variations in the shallow geothermal field occur. Since different energy minerals have varying requirements for thermal conditions, reflecting the differences in heat flow coupling under the influence of the thermal lithosphere structure through heat ratio values ​​can provide crucial evidence for the evaluation of energy minerals (such as oil and gas systems, metal deposits, and geothermal resources).

[0123] This embodiment identifies the boundary between the lithosphere and asthenosphere, i.e., the lower boundary of the lithosphere, thereby dividing the heat flow of the current region into two significantly different thermodynamic units: the lithosphere and the asthenosphere, based on thermodynamic principles, for lithospheric structural analysis. Furthermore, the layered heat flow values ​​corresponding to each lithological unit located above the lower boundary of the lithosphere are summed to obtain the lithospheric heat flow value. This facilitates the subsequent establishment of a quantitative characterization system for heat flow proportions based on the ratio of lithospheric to asthenospheric heat flow values. This achieves a strict distinction between conductive heat flow (shell-mantle radioactive heat generation) and convective heat flow (deep thermal energy input), establishing a structural classification standard based on thermodynamic mechanisms and avoiding the problem of overlapping and confusion of shell-mantle heat flow in traditional definitions.

[0124] It should be noted that the above examples are only for understanding this application and do not constitute a limitation on the lithosphere thermal structure analysis method of this application. Any simple modifications based on this technical concept are within the protection scope of this application.

[0125] This application also provides a lithosphere thermal structure analysis device; please refer to... Figure 4 , Figure 4 This is a schematic diagram of the modular structure of the lithosphere thermal structure analysis device of this application. The device includes:

[0126] The structural division module 401 is used to acquire rock information of the current region and construct a current lithosphere model based on the rock information. The current lithosphere model is composed of several layers of lithological units.

[0127] The first heat flow calculation module 402 is used to determine the surface geothermal heat flow value and the position of the bottom boundary of the lithosphere corresponding to the current lithosphere model based on the rock information and the preset temperature change rules.

[0128] The second heat flow calculation module 403 is used to determine the hierarchical heat flow value corresponding to each lithological unit located above the bottom boundary of the lithosphere based on the rock information, and to obtain the lithosphere heat flow value based on each hierarchical heat flow value.

[0129] The quantitative analysis module 404 is used to determine the heat flow ratio parameter by combining the Earth surface heat flow value and the lithosphere heat flow value, and to determine the heat flow ratio parameter as the lithosphere thermal structure analysis result of the current region.

[0130] This embodiment establishes a novel quantitative analysis method based on the thermodynamic nature of lithospheric heat flow (radioactive heat generation) dominated by conduction and asthenospheric heat flow (deep thermal energy) dominated by convection. Compared with existing methods, this embodiment achieves precise differentiation of heat flow properties, avoiding the problem of heat flow confusion in traditional studies; by establishing a quantitative characterization system for heat flow ratios, it provides a new analytical framework for the study of deep thermal structures; and by revealing the fine characteristics of heat source composition and heat transfer paths, it significantly improves the predictive accuracy of resource exploration such as oil and gas, geothermal, and metal deposits, providing an innovative theoretical foundation and technical support for mineral resource exploration.

[0131] This application also provides a lithosphere thermal structure analysis device, which includes: at least one processor; and a memory communicatively connected to the at least one processor; wherein the memory stores instructions executable by the at least one processor, the instructions being executed by the at least one processor to enable the at least one processor to perform the lithosphere thermal structure analysis method in the first embodiment described above.

[0132] The following is for reference. Figure 5 , Figure 5 This is a schematic diagram of the lithospheric thermal structure analysis device of this application. The lithospheric thermal structure analysis device in the embodiments of this application may include, but is not limited to, mobile terminals such as mobile phones, laptops, digital broadcast receivers, PDAs (Personal Digital Assistants), PADs (Portable Application Descriptions), PMPs (Portable Media Players), etc., as well as fixed terminals such as digital TVs, desktop computers, etc. Figure 5 The lithosphere thermal structure analysis device shown is merely an example and should not impose any limitation on the functionality and scope of use of the embodiments of this application.

[0133] like Figure 5 As shown, the lithosphere thermal structure analysis device may include a processor 1001 (e.g., a central processing unit, graphics processor, etc.), which can perform various appropriate actions and processes according to a program stored in read-only memory (ROM) 1002 or a program loaded from storage device 1003 into random access memory (RAM) 1004. The RAM 1004 also stores various programs and data required for the operation of the lithosphere thermal structure analysis device. The processor 1001, ROM 1002, and RAM 1004 are interconnected via a bus 1005. An input / output (I / O) interface 1006 is also connected to the bus. Typically, the following systems can be connected to the I / O interface 1006: input devices 1007 including, for example, a touchscreen, touchpad, keyboard, mouse, image sensor, microphone, accelerometer, gyroscope, etc.; output devices 1008 including, for example, a liquid crystal display (LCD), speaker, vibrator, etc.; storage devices 1003 including, for example, magnetic tape, hard disk, etc.; and communication devices 1009. Communication device 1009 allows the lithosphere thermal structure analysis equipment to communicate wirelessly or wiredly with other devices to exchange data. Although the figure shows a lithosphere thermal structure analysis equipment with various systems, it should be understood that implementation or possession of all the systems shown is not required. More or fewer systems may be implemented alternatively.

[0134] The lithosphere thermal structure analysis equipment provided in this application, employing the lithosphere thermal structure analysis method described in the above embodiments, can solve the technical problems of lithosphere thermal structure analysis. Compared with the prior art, the beneficial effects of the lithosphere thermal structure analysis equipment provided in this application are the same as those of the lithosphere thermal structure analysis method provided in the above embodiments, and other technical features of this lithosphere thermal structure analysis equipment are the same as those disclosed in the previous embodiment method, and will not be repeated here.

[0135] This application also provides a computer-readable storage medium having computer-readable program instructions (i.e., a computer program) stored thereon, the computer-readable program instructions being used to execute the lithosphere thermal structure analysis method in the above embodiments.

[0136] The computer-readable storage medium provided in this application may be, for example, a USB flash drive, but is not limited to, electrical, magnetic, optical, electromagnetic, infrared, or semiconductor systems, devices, or any combination thereof. More specific examples of computer-readable storage media may include, but are not limited to: electrical connections having one or more wires, portable computer disks, hard disks, random access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM or flash memory), optical fiber, portable compact disk read-only memory (CD-ROM), optical storage devices, magnetic storage devices, or any suitable combination thereof. In this embodiment, the computer-readable storage medium may be any tangible medium containing or storing a program that can be used by or in conjunction with an instruction execution system, system, or device. The program code contained on the computer-readable storage medium may be transmitted using any suitable medium, including but not limited to: wires, optical cables, RF (Radio Frequency), etc., or any suitable combination thereof.

[0137] The readable storage medium provided in this application is a computer-readable storage medium that stores computer-readable program instructions (i.e., a computer program) for executing the above-described lithosphere thermal structure analysis method, thereby solving the technical problems of lithosphere thermal structure analysis. Compared with the prior art, the beneficial effects of the computer-readable storage medium provided in this application are the same as those of the lithosphere thermal structure analysis method provided in the above embodiments, and will not be repeated here.

[0138] It should be noted that, in this document, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or system that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or system. Unless otherwise specified, an element defined by the phrase "comprising one..." does not exclude the presence of other elements in the process, method, article, or system that includes that element.

[0139] The sequence numbers of the above embodiments of the present invention are merely for description and do not represent the superiority or inferiority of the embodiments. They are only some embodiments of this application and are not intended to limit the scope of this application. All equivalent structural transformations made under the technical concept of this application and based on the content of the specification and drawings of this application, or direct / indirect applications in other related technical fields, are included within the protection scope of this application.

Claims

1. A method for analyzing the thermal structure of the lithosphere, characterized in that, The method includes: Obtain rock information for the current region and construct a current lithosphere model based on the rock information. The current lithosphere model consists of several layers of lithological units. Based on the rock information and the preset temperature change rules, determine the surface geothermal heat flow value and the location of the bottom boundary of the lithosphere corresponding to the current lithosphere model; Based on the rock information, determine the hierarchical heat flow value corresponding to each lithological unit located above the bottom boundary of the lithosphere, and obtain the lithosphere heat flow value based on each hierarchical heat flow value; The heat flow ratio parameter is determined by combining the Earth surface heat flow value and the lithosphere heat flow value, and the heat flow ratio parameter is used as the result of the lithosphere thermal structure analysis of the current region. The rock information includes: vertical rock category information. The step of determining the hierarchical heat flow value corresponding to each lithological unit located above the bottom boundary of the lithosphere based on the rock information, and obtaining the lithosphere heat flow value based on each hierarchical heat flow value, includes: The rock mass thickness of each lithological unit is determined based on the vertical rock type information; The heat generation rate information of each lithological unit is obtained, and the hierarchical heat flux value of each lithological unit is obtained based on the heat generation rate information and the corresponding rock mass thickness. The heat flow values ​​of the lithosphere are summed for the hierarchical heat flow values ​​corresponding to each lithological unit located above the bottom boundary of the lithosphere to obtain the lithosphere heat flow value; The step of determining the heat flow ratio parameters by combining the Earth's surface heat flow value and the lithosphere heat flow value includes: Subtracting the lithospheric heat flow value from the Earth's surface heat flow value yields the asthenospheric heat flow value. The heat flux ratio coefficient is obtained by dividing the lithospheric heat flux value by the asthenospheric heat flux value.

2. The method as described in claim 1, characterized in that, The step of acquiring rock information of the current region and constructing a current lithosphere model based on the rock information includes: Initialize the lithosphere hierarchy model and each lithological unit based on the standard lithosphere structure; Obtain vertical rock category information for the current area, wherein the vertical rock category information is obtained from rock surveying of the current area; Based on the vertical rock category information, the rock category corresponding to each lithological unit is determined, and the lithosphere hierarchical model is labeled based on the rock category correspondence to obtain the current lithosphere model.

3. The method as described in claim 1, characterized in that, The rock information also includes: measured temperature data. The step of determining the surface geothermal flow value and the location of the lithosphere floor corresponding to the current lithosphere model based on the rock information and preset temperature change rules includes: Based on the measured temperature data and in accordance with the preset temperature change rules, the average geothermal gradient corresponding to the current lithosphere model is determined; Based on the average geothermal gradient and the thermal conductivity information of each lithological unit, the surface geothermal heat flow value and the temperature data of each lithological unit are obtained. Geothermal distribution curves are generated based on the temperature data of each lithological unit, and the location of the lithosphere floor is obtained based on the geothermal distribution curves.

4. The method as described in claim 3, characterized in that, The step of obtaining the surface geothermal heat flow value and the temperature data of each lithological unit based on the average geothermal gradient and the thermal conductivity information of each lithological unit includes: The thermal conductivity information of each lithological unit is obtained, and the harmonic thermal conductivity is obtained based on the thermal conductivity information. The thermal conductivity information is the thermal conductivity measurement value of each rock type under the corresponding lithological unit conditions. The Earth's surface heat flow value is determined based on the average geothermal gradient and the harmonic thermal conductivity. The heat generation rate information of each lithological unit is obtained, and the temperature data of each lithological unit is determined layer by layer based on the heat generation rate information, the thermal conductivity information, and the surface geothermal heat flow value.

5. The method as described in claim 3, characterized in that, The step of generating geothermal distribution curves based on the temperature data of each lithological unit, and obtaining the location of the lithosphere floor based on the geothermal distribution curves, includes: Geothermal distribution curves are generated based on the temperature data of each lithological unit; The intersection point analysis is performed between the geothermal distribution curve and at least one standard reference line to obtain the target intersection point position, and the corresponding value of the target intersection point position is determined as the position of the bottom boundary of the lithosphere. The standard reference line includes: the solid phase line of the rock and the mantle adiabatic line.

6. A lithosphere thermal structure analysis device, characterized in that, The device includes: The structural partitioning module is used to acquire rock information of the current region and construct a current lithosphere model based on the rock information. The current lithosphere model consists of several layers of lithological units. The first heat flow calculation module is used to determine the surface geothermal heat flow value and the location of the bottom boundary of the lithosphere corresponding to the current lithosphere model based on the rock information and preset temperature change rules. The second heat flow calculation module is used to determine the hierarchical heat flow value corresponding to each lithological unit located above the bottom boundary of the lithosphere based on the rock information, and to obtain the lithosphere heat flow value based on each hierarchical heat flow value. The quantitative analysis module is used to determine the heat flow ratio parameter by combining the Earth surface heat flow value and the lithosphere heat flow value, and to determine the heat flow ratio parameter as the lithosphere thermal structure analysis result of the current region. The rock information includes: vertical rock category information; The second heat flow calculation module is further configured to determine the rock mass thickness of each lithological unit based on the vertical rock type information; obtain the heat generation rate information of each lithological unit, and obtain the hierarchical heat flow value of each lithological unit based on the heat generation rate information and the corresponding rock mass thickness; and sum the hierarchical heat flow values ​​corresponding to each lithological unit located above the bottom boundary of the lithosphere to obtain the lithosphere heat flow value. The quantitative analysis module is also used to subtract the lithosphere heat flow value from the Earth's surface heat flow value to obtain the asthenosphere heat flow value; and to divide the lithosphere heat flow value by the asthenosphere heat flow value to obtain the heat flow ratio coefficient.

7. A lithosphere thermal structure analysis device, characterized in that, The device includes a memory, a processor, and a lithosphere thermal structure analysis program stored in the memory and executable on the processor, wherein the lithosphere thermal structure analysis program, when executed by the processor, implements the steps of the lithosphere thermal structure analysis method as described in any one of claims 1 to 5.

8. A storage medium, characterized in that, The storage medium stores a lithosphere thermal structure analysis program, which, when executed by a processor, implements the steps of the lithosphere thermal structure analysis method as described in any one of claims 1 to 5.

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