Method and device for determining carbon emission and energy consumption of whole process of heavy oil thermal recovery development

Abstract

The present application relates to a method and device for determining carbon emissions and energy consumption in the whole process of heavy oil thermal recovery development, and relates to the cross technical field of oil and gas development and low-carbon emission reduction. The whole process of heavy oil thermal recovery development includes multiple injection development links and multiple production development links. The method includes: determining the carbon emissions and energy consumption of each injection development link based on an energy balance model and a series thermal resistance model. The energy balance model is used to represent the energy conservation relationship of boiler steam generation. The series thermal resistance model is used to represent the series relationship of multiple layers of thermal resistance of pipelines or wellbores. The carbon emissions and energy consumption of each production development link are determined based on a lifting power model, a heat loss compensation model and an energy consumption conversion model. The lifting power model is used to represent the conversion relationship between lifting power consumption and hydraulic power. The heat loss compensation model is used to represent the conversion relationship between wellbore heat loss and heat tracing energy consumption. The energy consumption conversion model is used to represent the conversion relationship between fuel consumption or power consumption and carbon emissions.

Description

Technical Field

[0001] The embodiments in this specification relate to the cross-technical fields of oil and gas development and low-carbon emission reduction, specifically to the methods and apparatus for determining carbon emissions and energy consumption throughout the entire process of heavy oil thermal recovery development. Background Technology

[0002] Since the large-scale application of heavy oil thermal recovery technology, the traditional development model mainly relies on boilers burning fossil fuels such as coal and natural gas to produce steam, and achieve crude oil viscosity reduction and extraction through steam injection, steam drive and steam-assisted gravity drainage. However, this process has problems such as incomplete coverage and insufficient accuracy in carbon emission and energy consumption accounting. Summary of the Invention

[0003] The purpose of the embodiments in this specification is to provide a method and apparatus for determining carbon emissions and energy consumption throughout the entire process of heavy oil thermal recovery development, so as to overcome the problems of incomplete coverage and insufficient accuracy in existing methods.

[0004] To address the aforementioned technical issues, this specification provides, on the one hand, a method for determining carbon emissions and energy consumption throughout the entire heavy oil thermal recovery development process, which includes multiple injection development stages and multiple production development stages. The method includes: Based on the energy balance model and the series thermal resistance model, the carbon emissions and energy consumption of each injection development stage are determined; the energy balance model is used to characterize the energy conservation relationship of boiler steam production; the series thermal resistance model is used to characterize the multi-layer thermal resistance series relationship of pipelines or wells. Based on the lifting power model, heat loss compensation model, and energy consumption conversion model, the carbon emissions and energy consumption of each production and development stage are determined. The lifting power model is used to characterize the conversion relationship between lifting power consumption and hydraulic work. The heat loss compensation model is used to characterize the conversion relationship between wellbore heat loss and heat tracing energy consumption. The energy consumption conversion model is used to characterize the conversion relationship between fuel consumption or electricity consumption and carbon emissions.

[0005] Furthermore, the injection development stage includes a boiler steam generation stage; the energy balance model is used to characterize the energy conservation relationship between the lower heating value of fuel, boiler efficiency, steam enthalpy and feedwater enthalpy in the boiler steam generation stage. The carbon emissions and energy consumption of each injection development stage are determined based on the energy balance model and the series thermal resistance model, including: Based on the energy balance model, the steam production per unit of fuel is determined; The carbon emissions and energy consumption of the boiler steam production process are determined based on steam output, fuel consumption, fuel carbon content, carbon oxidation rate, and lower heating value of the fuel.

[0006] Furthermore, the injection development stage also includes a steam injection pipeline stage; the series thermal resistance model includes a first series thermal resistance model; the first series thermal resistance model is used to characterize the series relationship between the liquid film layer convective heat transfer thermal resistance, the pipe wall thermal conductivity thermal resistance, the insulation layer thermal conductivity thermal resistance, and the forced convection heat transfer thermal resistance between the insulation layer and the atmosphere. The determination of carbon emissions and energy consumption for each injection and development stage based on the energy balance model and series thermal resistance model also includes: Based on the first series thermal resistance model, the total thermal resistance of the steam injection pipeline is determined; The heat loss of the pipeline is determined based on the steam temperature, ambient temperature, total thermal resistance of the steam injection pipeline, and length of the steam injection pipeline. Based on the heat loss of the pipeline and the enthalpy of the steam, determine the carbon emissions and energy consumption generated by the boiler steam production heat loss in the steam injection pipeline.

[0007] Furthermore, the injection development stage includes the steam injection wellbore stage; the series thermal resistance model includes a second series thermal resistance model; the second series thermal resistance model is used to characterize the series relationship between the thermal resistance of the steam injection pipe wall, the thermal resistance of the insulation layer, the annular convection heat transfer thermal resistance, the annular radiation heat transfer thermal resistance, the casing wall thermal resistance, the cement sheath thermal resistance, and the formation thermal resistance. The determination of carbon emissions and energy consumption for each injection and development stage based on the energy balance model and series thermal resistance model also includes: Based on the second series thermal resistance model, the total thermal resistance of the wellbore is determined; The heat loss of the wellbore is determined based on the steam injection temperature, formation temperature, total thermal resistance of the wellbore, formation thermal resistance, and well depth. Based on the heat loss of the well shaft and the enthalpy of the steam, determine the carbon emissions and energy consumption generated by the boiler steam production heat loss in the steam injection well shaft stage.

[0008] Furthermore, the production development stage includes a production well lifting stage; the lifting power model is used to characterize the conversion relationship between power consumption and hydraulic work, transmission system efficiency, and pump efficiency during the process of lifting the produced fluid from the bottom of the well to the wellhead. The carbon emissions and energy consumption of each extraction and development stage are determined based on the lifting power model, heat loss compensation model, and energy consumption conversion model, including: Based on the aforementioned lifting power model, the daily power consumption is determined; Based on the daily power consumption and the power grid carbon emission factor, the carbon emissions and energy consumption of the production well lifting process are determined.

[0009] Furthermore, the production and development stage also includes a wellbore heating stage; the heat loss compensation model is used to characterize the temperature difference relationship between the average wellbore temperature and the formation temperature. The determination of carbon emissions and energy consumption for each extraction and development stage based on the lifting power model, heat loss compensation model, and energy consumption conversion model also includes: Based on the aforementioned heat loss compensation model, the daily heat loss of the wellbore is determined; Based on the daily heat loss of the well shaft, boiler efficiency, and fuel carbon emission factor, the carbon emissions and energy consumption of the well shaft heat tracing process are determined.

[0010] Furthermore, the production and development stage also includes a fluid gathering and transportation stage; the energy consumption conversion model includes a first energy consumption conversion model; the first energy consumption conversion model is used to characterize the conversion relationship between the heating energy required to maintain the flow of produced fluid in the surface pipeline and the fuel consumption; The determination of carbon emissions and energy consumption for each extraction and development stage based on the lifting power model, heat loss compensation model, and energy consumption conversion model also includes: Based on the first energy consumption conversion model, the daily heat loss of the transportation pipeline is determined; Based on the daily heat loss, boiler efficiency, and fuel carbon emission factor, the carbon emissions and energy consumption of the fluid gathering and transportation process are determined.

[0011] Furthermore, the extraction and development stage also includes a surface processing stage; the energy consumption conversion model includes a second energy consumption conversion model; the second energy consumption conversion model is used to characterize the conversion relationship between the heat required for oil-water separation and crude oil dehydration processes and fuel consumption; The determination of carbon emissions and energy consumption for each extraction and development stage based on the lifting power model, heat loss compensation model, and energy consumption conversion model also includes: Based on the second energy consumption conversion model, the daily fuel consumption required for oil-water separation is determined; Based on the daily fuel consumption, fuel carbon content, carbon oxidation rate, boiler efficiency, and fuel calorific value, the carbon emissions and energy consumption of the ground treatment process are determined.

[0012] Furthermore, the extraction and development stage also includes an efflux reinjection stage; the energy consumption conversion model includes a third energy consumption conversion model; the third energy consumption conversion model is used to characterize the conversion relationship between the electricity consumption and carbon emissions required for the carbon dioxide capture, compression and injection underground storage system; The determination of carbon emissions and energy consumption for each extraction and development stage based on the lifting power model, heat loss compensation model, and energy consumption conversion model also includes: Based on the aforementioned third energy consumption conversion model, the daily power consumption of the reinjection system is determined; Based on the daily power consumption, determine the daily carbon emissions and daily energy consumption of the reinjection system; The direct carbon emissions are determined based on the difference between the total fugitive carbon emissions and the recovered and reinjected carbon emissions. Based on the daily carbon emissions, daily energy consumption, and direct escaping carbon emissions of the reinjection system, the carbon emissions and energy consumption of the escaping reinjection process are determined.

[0013] On the other hand, the embodiments of this specification provide a device for determining carbon emissions and energy consumption throughout the entire process of heavy oil thermal recovery and development, which includes multiple injection development stages and multiple production development stages. The device includes: The first determining module is used to determine the carbon emissions and energy consumption of each injection development stage based on the energy balance model and the series thermal resistance model; the energy balance model is used to characterize the energy conservation relationship of boiler steam production; the series thermal resistance model is used to characterize the multi-layer thermal resistance series relationship of pipelines or wells. The second determination module is used to determine the carbon emissions and energy consumption of each extraction and development stage based on the lifting power model, heat loss compensation model, and energy consumption conversion model.

[0014] Furthermore, embodiments of this specification provide a computer device, including: Memory, used to store computer programs; A processor is used to execute the computer program to implement the method for determining carbon emissions and energy consumption throughout the entire process of heavy oil thermal recovery development.

[0015] Furthermore, this specification provides a computer storage medium storing computer program instructions, which, when executed, implement the aforementioned method for determining carbon emissions and energy consumption throughout the entire heavy oil thermal recovery development process.

[0016] On another note, embodiments of this specification provide a computer program product, including a computer program that, when executed by a processor, implements the aforementioned method for determining carbon emissions and energy consumption throughout the entire heavy oil thermal recovery development process.

[0017] As can be seen from the technical solutions provided in the embodiments of this specification above, the embodiments of this specification can determine the carbon emissions and energy consumption of each injection development stage based on the energy balance model and the series thermal resistance model; the energy balance model is used to characterize the energy conservation relationship of boiler steam production; the series thermal resistance model is used to characterize the multi-layer thermal resistance series relationship of pipelines or wells; the carbon emissions and energy consumption of each production development stage are determined based on the lifting power model, the heat loss compensation model, and the energy consumption conversion model; the lifting power model is used to characterize the conversion relationship between lifting power consumption and hydraulic work; the heat loss compensation model is used to characterize the conversion relationship between wellbore heat loss and heat tracing energy consumption; the energy consumption conversion model is used to characterize the conversion relationship between fuel consumption or electricity consumption and carbon emissions. By using energy balance and series thermal resistance models, a systematic and refined evaluation of carbon emissions and energy consumption at each stage of injection is achieved. By using lifting power model, heat loss compensation model and energy consumption conversion model, the sub-items of each stage at production are quantified. A carbon emission and energy consumption evaluation system covering the entire process is constructed, providing a quantitative basis for the low-carbon optimization and clean energy substitution benefit assessment of heavy oil thermal recovery. Attached Figure Description

[0018] To more clearly illustrate the technical solutions in the embodiments or prior art of this specification, the accompanying drawings used in the description of the embodiments or prior art will be briefly introduced below.

[0019] Figure 1 This is a flowchart of the method for determining carbon emissions and energy consumption throughout the entire process of heavy oil thermal recovery development provided in the embodiments of this specification; Figure 2 This is a schematic diagram comparing the carbon emissions per ton of steam injected at the bottom of the well for different development methods provided in the embodiments of this specification; Figure 3 This is a schematic diagram of the steam energy consumption per ton of steam at the bottom injection end for different development methods provided in the embodiments of this specification; Figure 4 This is a schematic diagram illustrating the variation of unit carbon emission oil exchange rate at the injection end under different development methods provided in the embodiments of this specification; Figure 5 This is a schematic diagram illustrating the variation of unit energy consumption oil change rate at the injection end under different development methods provided in the embodiments of this specification; Figure 6 This is a schematic diagram comparing the unit carbon emissions and energy consumption oil change rate of the injection end under different development methods provided in the embodiments of this specification; Figure 7 This is a schematic diagram of the cumulative carbon emissions at the extraction end provided in the embodiments of this specification; Figure 8 This is a schematic diagram illustrating the cumulative energy consumption change at the extraction end provided in the embodiments of this specification; Figure 9 This is a schematic diagram comparing the cumulative carbon emissions and energy consumption at the extraction end provided in the embodiments of this specification; Figure 10 This is a schematic diagram illustrating the changes in unit carbon emission oil change rate throughout the entire process under different development methods, provided in the embodiments of this specification. Figure 11 This is a schematic diagram illustrating the changes in unit energy consumption and oil change rate throughout the entire process of different development methods provided in the embodiments of this specification; Figure 12 This is a schematic diagram comparing the unit carbon emissions, energy consumption, and oil change rate of different development methods throughout the entire process, as provided in the embodiments of this specification. Figure 13 This is a schematic diagram of the structure of the carbon emission and energy consumption determination device for the entire process of heavy oil thermal recovery development provided in the embodiments of this specification; Figure 14 This is a schematic diagram of the structural composition of a computer device provided in the embodiments of this specification. Detailed Implementation

[0020] The technical solutions in the embodiments of this specification will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this specification, and not all embodiments. Based on the embodiments in this specification, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of this specification.

[0021] It should be noted that the terms "first," "second," etc., used in this specification, claims, and the foregoing drawings are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments described herein can be implemented in orders other than those illustrated or described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover a non-exclusive inclusion; for example, a process, method, apparatus, product, or device that includes a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or devices.

[0022] In some embodiments, the entire process of heavy oil thermal recovery development may include multiple injection development stages and multiple production development stages. The injection development stage includes three sub-stages: boiler steam generation, surface pipeline transportation, and injection wellbore. The production development stage includes five sub-stages: production well lifting, wellbore heating, fluid gathering and transportation, surface treatment, and effluent reinjection.

[0023] The boiler steam generation stage is used to generate high-temperature and high-pressure steam by burning fossil fuels, providing an injection medium for heavy oil thermal recovery. Its function is to convert the chemical energy of the fuel into the thermal energy of the steam.

[0024] The ground pipeline transportation link is used to transport the high-temperature steam generated by the boiler from the boiler room to the injection wellhead. Its function is to maintain the thermal state of the steam during long-distance transportation and reduce heat loss along the way.

[0025] The injection wellbore section is used to inject steam from the surface into the target reservoir layer along the wellbore. Its function is to transport steam from the wellhead to the bottom of the well, overcome the heat loss caused by the formation temperature gradient, and ensure that steam with sufficient heat enters the reservoir.

[0026] The production well lift stage is used to lift the produced fluid from the bottom of the well to the wellhead. Its function is to overcome gravity and lift the fluid to the surface to provide power for subsequent processing.

[0027] The wellbore heating system is used to compensate for the heat loss of the produced fluid to the formation during the wellbore as it rises. Its function is to maintain the temperature of the produced fluid above the wax precipitation point or freezing point, ensuring the normal flow of fluid within the wellbore.

[0028] The fluid gathering and transportation stage is used to collect the produced fluids from each well through surface pipelines to the treatment station. Its function is to maintain the fluidity of the produced fluid during transportation and prevent the viscosity from increasing or solidifying due to temperature drop.

[0029] The surface processing stage is used to separate oil, gas and water and dehydrate crude oil after the collected produced fluid. Its function is to separate commercial crude oil that meets the export standards and to treat the separated water to meet the standards before reinjection or discharge.

[0030] The escape and reinjection stage is used to capture greenhouse gases such as carbon dioxide generated during the processing and then compress them before injecting them into underground storage or reinjection reservoirs. Its function is to reduce carbon emissions that directly escape into the atmosphere and achieve partial carbon sequestration and utilization.

[0031] This specification provides an embodiment of a method for determining carbon emissions and energy consumption throughout the entire process of heavy oil thermal recovery development. (Refer to...) Figure 1 As shown, the specific implementation may include the following steps: S101: Based on the energy balance model and the series thermal resistance model, determine the carbon emissions and energy consumption of each injection development stage.

[0032] In some embodiments, step S101 may specifically include: determining the carbon emissions and energy consumption of each injection development stage based on the energy balance model and the series thermal resistance model.

[0033] In some embodiments, the energy balance model is used to characterize the energy conservation relationship of boiler steam production; the series thermal resistance model is used to characterize the multi-layer thermal resistance series relationship of pipelines or wells.

[0034] The energy balance model is used to characterize the energy conservation relationship in the boiler steam generation process. Specifically, it uses the steam enthalpy as the core parameter, combined with the lower heating value of the fuel, boiler efficiency, and feedwater enthalpy to construct the mass-energy balance equation. Here, the lower heating value of the fuel represents the heat released by the complete combustion of a unit mass of fuel, measured in kilojoules per kilogram; boiler efficiency represents the effective proportion of fuel combustion heat converted into steam heat; steam enthalpy represents the total thermal energy contained in a unit mass of steam, measured in kilojoules per kilogram; and feedwater enthalpy represents the thermal energy contained in the feedwater entering the boiler. This model can determine the steam output per unit of fuel, i.e., the number of tons of steam produced per ton of fuel.

[0035] The series thermal resistance model includes a first series thermal resistance model and a second series thermal resistance model. Based on the steady-state heat transfer assumption, the first series thermal resistance model is used to characterize the multi-layer heat transfer path of steam as it is transported from the boiler to the wellhead, sequentially passing through the liquid film layer for convection, the pipe wall for heat conduction, the insulation layer for heat conduction, and the outer surface of the insulation layer for convective heat transfer along the surface pipeline. Specifically, the liquid film layer convective heat transfer resistance characterizes the convective heat transfer resistance between the inner wall of the pipe and the steam, and is affected by the steam velocity, properties, and pipe diameter; the pipe wall for heat conduction resistance characterizes the thermal resistance of the steel pipe wall itself, depending on the pipe wall thickness and the material's thermal conductivity; the insulation layer for heat conduction resistance characterizes the insulation capacity of the insulation material, depending on the insulation layer thickness and the material's thermal conductivity; and the forced convection heat transfer resistance between the insulation layer and the atmosphere characterizes the convective heat transfer resistance between the outer surface of the insulation layer and the atmospheric environment, and is affected by ambient wind speed and temperature. Ignoring pipeline heat capacity and pressure variations along the pipeline, the total pipeline thermal resistance is obtained by summing the thermal resistances of each layer. Combining this with steam temperature and ambient temperature, the heat conduction per unit time per unit length of pipeline can be determined. Multiplying this by the pipeline length and operating time yields the total pipeline heat loss. This heat loss is then converted into the additional fuel consumption required to compensate for it, thereby determining the carbon emissions and energy consumption resulting from the heat loss.

[0036] Based on unsteady-state heat transfer theory, considering the increase in formation thermal resistance with steam injection time, a second series thermal resistance model is used to characterize the multi-layered heat transfer path of steam from the wellhead to the bottom of the well, sequentially passing through the steam injection pipe wall, insulation layer, annular convection and radiation heat transfer, casing wall, and cement sheath. Annular convection and radiation heat transfer includes the natural convection thermal resistance of the gas within the annulus and the radiation thermal resistance between the high-temperature and low-temperature surfaces; cement sheath thermal resistance characterizes the thermal resistance of the cement sheath, affected by its thickness and thermal conductivity; formation thermal resistance characterizes the resistance to heat transfer from the outer edge of the cement sheath to the infinitely large formation, calculated using unsteady-state heat transfer theory, and its value increases with steam injection time. By calculating the sum of the thermal resistances of each layer, the total thermal resistance of the wellbore is obtained. Combining the steam injection temperature and the formation temperature varying along the well depth, the heat conduction per unit time per unit depth of the wellbore can be determined. Multiplying this by the well depth and operating time yields the total heat loss of the wellbore. The amount of heat loss is converted into the additional fuel consumption required to replenish the loss, thereby determining the carbon emissions and energy consumption caused by the heat loss.

[0037] By constructing the surface pipeline and wellbore into a multi-layer series thermal resistance structure, the shortcomings of conventional simplified treatments that cannot accurately reflect the heat transfer law under the high temperature, high pressure, and long distance transportation conditions of heavy oil thermal recovery are overcome. The dynamic correlation between heat loss and carbon emissions at the injection end is realized, providing a refined evaluation basis for identifying energy consumption hotspots at the injection end.

[0038] S102: Based on the lifting power model, heat loss compensation model and energy consumption conversion model, determine the carbon emissions and energy consumption of each extraction and development stage.

[0039] In some embodiments, step S102 may specifically include: determining the carbon emissions and energy consumption of each extraction and development stage based on the lifting power model, the heat loss compensation model, and the energy consumption conversion model.

[0040] In some embodiments, the lifting power consumption model is used to characterize the conversion relationship between lifting power consumption and hydraulic work; the heat loss compensation model is used to characterize the conversion relationship between wellbore heat loss and heat tracing energy consumption; and the energy consumption conversion model is used to characterize the conversion relationship between fuel consumption or electricity consumption and carbon emissions.

[0041] The hydraulic lift model is used to characterize the conversion relationship between power consumption, hydraulic work, transmission system efficiency, and pump efficiency during the process of lifting produced fluid from the bottom of the well to the wellhead. Hydraulic work represents the theoretical minimum work required to overcome gravity and lift the produced fluid to the wellhead; the calculation formula is based on the daily produced fluid mass, gravitational acceleration, and well depth. Transmission system efficiency represents the efficiency of energy transfer from electrical energy to mechanical energy. Pump efficiency represents the efficiency of the lifting equipment in converting mechanical energy into liquid potential energy.

[0042] The heat loss compensation model is used to characterize the temperature difference between the average wellbore temperature and the formation temperature in the wellbore heating process. The average wellbore temperature is determined by the production-weighted average temperature method, which calculates the bottom hole temperature based on the bottom hole temperatures corresponding to the high, medium, and low daily fluid production values ​​and their production-weighted proportions, and then averages the result with the target wellhead temperature.

[0043] The energy consumption conversion models include a first energy consumption conversion model, a second energy consumption conversion model, and a third energy consumption conversion model. The first energy consumption conversion model characterizes the conversion relationship between the heat tracing energy required to maintain the flow of produced fluid in surface pipelines and fuel consumption. Its core is to calculate heat loss based on the pipeline maintenance temperature and ambient temperature, and then convert it to fuel consumption based on boiler efficiency. The second energy consumption conversion model characterizes the conversion relationship between the heat required for oil-water separation and crude oil dehydration processes and fuel consumption. Its core is to calculate the required heat based on fluid throughput, specific heat capacity, and target temperature difference, and then convert it to fuel consumption based on boiler efficiency. The third energy consumption conversion model characterizes the conversion relationship between the electricity consumption and carbon emissions required for carbon dioxide capture, compression, and injection into underground storage systems. Its core is to calculate electricity consumption based on the amount of recovered and reinjected carbon dioxide and the power consumption coefficient of the reinjection system, and then convert it to carbon emissions based on the grid carbon emission factor.

[0044] By linking lifting energy consumption to the physical work process through the hydraulic lift model, the crudeness of empirical estimation is avoided; by using the production-weighted average temperature method in the heat loss compensation model, the defect that the fixed temperature assumption cannot reflect dynamic production conditions is overcome; by using three sets of energy consumption conversion models to handle the gathering, transportation, processing and reinjection links respectively, a refined sub-item evaluation of carbon emissions and energy consumption at each link of the production end is realized.

[0045] In some embodiments, step S201 may further include: determining the carbon emissions and energy consumption of each injection development stage based on the energy balance model and the series thermal resistance model, and inputting the injection parameters into the reservoir numerical simulation model.

[0046] Injection parameters can include steam injection rate, steam injection temperature, and steam dryness fraction. The steam injection rate represents the mass of steam injected into the reservoir per unit time, measured in tons per day; the steam injection temperature represents the temperature of the steam injected at the bottom of the well, measured in degrees Celsius; and the steam dryness fraction represents the mass proportion of the gas phase in the steam, and is dimensionless. These parameters, calculated at the injection end using an energy balance model and a series thermal resistance model, are then input as boundary conditions into the reservoir numerical simulation model.

[0047] In some embodiments, step S202 may further include: simulating dynamic production data based on injection parameters using a reservoir numerical simulation model; and determining carbon emissions and energy consumption for each production and development stage based on the dynamic production data using a hydraulic lift model, a heat loss compensation model, and an energy consumption conversion model.

[0048] The reservoir numerical simulation model can employ a field-scale grid system, dividing the reservoir into multiple grid cells. Each cell is assigned basic parameters such as porosity, permeability, oil saturation, reservoir temperature, and crude oil viscosity. During the simulation, the injection parameters determined in step S201 are used as input conditions. By solving the mass conservation equation, energy conservation equation, and Darcy's law, dynamic production data at different time steps are calculated. The dynamic production data includes fluid production, oil production, and gas production. Fluid production represents the total volume of liquid extracted from the wellhead per unit time, in cubic meters per day; oil production represents the volume of crude oil extracted per unit time, in cubic meters per day; and gas production represents the volume of associated gas extracted per unit time, in cubic meters per day.

[0049] Production dynamics data serve as input parameters for evaluation models at each stage of the production process. Specifically, the production volume is used to calculate the daily production mass in the hydraulic lift model, thereby determining the lift power consumption and corresponding carbon emissions; the production volume and its corresponding bottom hole temperature are used to calculate the production weighted average temperature method in the heat loss compensation model, thereby determining the carbon emissions and energy consumption required for wellbore heating; and the production volume and its components are used to calculate the fluid gathering and transportation, surface treatment, and effluent reinjection stages in the energy consumption conversion model.

[0050] By coupling injection parameters with reservoir numerical simulation and then using dynamic data from the simulated production to drive the production-end evaluation model, a dynamic correlation between the injection and production ends is achieved, overcoming the shortcomings of existing methods where injection and production are isolated from each other. This closed-loop structure allows adjustments to injection parameters to be reflected in the carbon emission and energy consumption calculations at each stage of the production end in real time, providing global data support for the optimization of the entire process and enabling precise quantification of the impact of changes in the injection scheme on overall carbon emissions and energy consumption.

[0051] In some embodiments, the energy balance model described above is used to characterize the energy conservation relationship between the lower heating value of fuel, boiler efficiency, steam enthalpy, and feedwater enthalpy in the boiler steam generation process. Based on this, step S101 may further include: determining the steam output per unit of fuel based on the energy balance model; and determining the carbon emissions and energy consumption of the boiler steam generation process based on the steam output, fuel consumption, fuel carbon content, carbon oxidation rate, and lower heating value of fuel.

[0052] Based on the energy balance model, the steam output per unit of fuel can be determined. The energy balance model characterizes the fact that the heat released by fuel combustion, minus boiler heat losses, equals the net heat absorbed by the steam. The total heat released by fuel combustion is represented by the product of fuel consumption and the lower heating value of the fuel, where the lower heating value can be the heat released by the complete combustion of a unit mass of fuel. This value depends on the type of fuel (e.g., raw coal, natural gas), and is expressed in kilojoules per kilogram. Boiler heat losses are indirectly reflected by boiler efficiency, which refers to the effective proportion of fuel combustion heat converted into steam heat. Its value is determined by the boiler type, operating conditions, and insulation performance, and is dimensionless. The net heat absorbed by the steam is obtained by multiplying the steam output by the heat absorbed per unit mass of steam. The heat absorbed per unit mass of steam is the difference between the saturated steam enthalpy and the feedwater enthalpy. The saturated steam enthalpy refers to the total thermal energy contained in saturated steam at the target pressure, while the feedwater enthalpy refers to the initial thermal energy contained in the feedwater entering the boiler; both are expressed in kilojoules per kilogram. By establishing the above energy conservation relationship, the quantitative relationships between fuel consumption, lower heating value of fuel, boiler efficiency, steam output, steam enthalpy and feedwater enthalpy are established, thereby calculating the steam output corresponding to a unit of fuel.

[0053] The carbon emissions and energy consumption of the boiler steam generation process can be determined based on steam output, fuel consumption, fuel carbon content, carbon oxidation rate, and lower heating value of the fuel. Carbon emissions are determined according to the carbon mass balance principle: the carbon in the fuel is oxidized to carbon dioxide during combustion, and its mass equals the product of fuel consumption, fuel carbon content, and carbon oxidation rate, multiplied by the atomic weight conversion factor between carbon dioxide and carbon. Here, fuel carbon content refers to the mass ratio of carbon in a unit mass of fuel, determined by fuel elemental analysis; carbon oxidation rate refers to the proportion of carbon in the fuel oxidized to carbon dioxide, reflecting the degree of complete combustion; and the atomic weight conversion factor of 3.67 is the ratio of the molecular weight of carbon dioxide (44) to the atomic weight of carbon (12). Energy consumption is determined according to the principle of fuel calorific value utilization: the actual primary energy consumed in the boiler steam generation process equals the product of fuel consumption, lower heating value of the fuel, and boiler efficiency. This value characterizes the heat energy effectively absorbed by the steam and reflects the true energy consumption level of the steam generation process.

[0054] By establishing a physical relationship between fuel input and steam output through an energy balance model, a quantitative evaluation of carbon emissions and energy consumption in the boiler steam generation process is achieved. Compared with estimation methods based on empirical coefficients, this model can dynamically adjust the calculation results according to actual fuel characteristics (lower heating value, carbon content) and boiler operating conditions (efficiency), avoiding the bias caused by fixed coefficients. The introduction of fuel carbon content and carbon oxidation rate makes the calculation of carbon emissions accurate to the chemical process of fuel combustion; the introduction of boiler efficiency makes the calculation of energy consumption reflect the actual effective energy utilization.

[0055] In some embodiments, the above-mentioned determination of steam production per unit of fuel based on the energy balance model; and the determination of carbon emissions and energy consumption in the boiler steam generation process based on steam production, fuel consumption, fuel carbon content, carbon oxidation rate, and lower heating value of fuel, may further include: Calculate the steam output at the boiler's steam-generating end using the following formula: In the formula, The lower heating value of the fuel is kJ / kg; The enthalpy of saturated steam is expressed in kJ / kg. The amount of fuel required to generate one ton of steam, in tons; The enthalpy of saturated water at 25℃ is expressed in kJ / kg. The boiler efficiency is %. Among them, Characterizes the total mass of fuel consumed by the boiler during the calculation period; Characterized by the heat released from the complete combustion of a unit mass of fuel, this value can be determined by industrial or elemental analysis of the fuel. It represents the proportion of heat released by fuel combustion that is absorbed by steam, and its value depends on the boiler type, operating conditions, and insulation performance. The total heat energy contained in saturated steam at the target pressure is determined by referring to the table of thermodynamic properties of steam based on the target steam temperature. Characterizes the initial thermal energy of feedwater when it enters the boiler.

[0056] In the above formula, the denominator is the net heat absorbed by a unit mass of steam in the boiler. Based on the principle of energy conservation, the numerator is the effective heat released by fuel combustion, and the denominator is the net heat absorbed per unit mass of steam. Dividing the two yields the total amount of steam that can be produced from the fuel.

[0057] Calculate the carbon emissions at the boiler steam generation end using the following formula: In the formula, The mass of fuel is expressed in tons (t). The carbon content of fuel, % is the carbon oxidation rate, %; 3.67 is the atomic weight conversion factor. Among them, The mass ratio of carbon in a unit mass of fuel is determined by elemental analysis of the fuel. Characterizes the proportion of carbon in fuel that is oxidized to carbon dioxide.

[0058] The above formula calculates the mass of carbon element oxidized by multiplying the fuel consumption, carbon content, and carbon oxidation rate, and then multiplies it by a conversion factor to obtain the mass of carbon dioxide emissions.

[0059] Calculate the boiler steam generation energy consumption using the following formula: In the formula, The mass of fuel is expressed in tons (t). The lower heating value of the fuel is kJ / kg; For boiler efficiency, %.

[0060] The above formula calculates the actual primary energy consumed in the boiler steam generation process, that is, the heat energy released by fuel combustion and effectively absorbed by steam, expressed in kilojoules (kJ) or gigajoules (GJ). This value reflects the true energy consumption level of the boiler steam generation process.

[0061] Calculate the carbon emissions per ton of steam at the boiler steam production end using the following formula: In the formula, Carbon emissions at the boiler steam generation end, in tons; The steam conversion rate at the boiler steam generation end is expressed in tons (t). The carbon emissions per ton of steam represent the carbon emissions generated per unit mass of steam produced, used for cross-sectional comparisons after eliminating the influence of production scale.

[0062] Calculate the energy consumption per ton of steam at the boiler steam generation end using the following formula: In the formula, Energy consumption at the boiler steam generation end, GJ; Let be the steam conversion rate at the boiler steam generation end, expressed in tons (t). Here, ton steam energy consumption represents the amount of energy consumed to produce a unit mass of steam.

[0063] A mathematical evaluation system for carbon emissions and energy consumption in boiler steam generation was established using the five sets of formulas described above. Steam production calculation is based on the principle of energy conservation, avoiding errors caused by empirical estimations; carbon emissions calculation uses atomic weight conversion factors to accurately convert the mass of carbon elements into the mass of carbon dioxide; energy consumption calculation directly reflects effective energy consumption. The introduction of the ton-of-steam index makes it comparable between different operating conditions and steam generation methods, providing a quantitative benchmark for the subsequent assessment of the carbon reduction potential of multi-energy coupled steam generation modes. The parameters in each formula have clear physical meanings and industry standard acquisition methods, ensuring the objectivity and reproducibility of the evaluation results.

[0064] In some embodiments, the aforementioned series thermal resistance model includes a first series thermal resistance model; the first series thermal resistance model is used to characterize the series relationship between the convective heat transfer thermal resistance of the liquid film layer, the thermal conductivity thermal resistance of the pipe wall, the thermal conductivity thermal resistance of the insulation layer, and the forced convective heat transfer thermal resistance between the insulation layer and the atmosphere. Based on this, the aforementioned step S101 may further include: determining the total thermal resistance of the steam injection pipeline based on the first series thermal resistance model; determining the pipeline heat loss based on the steam temperature, ambient temperature, the total thermal resistance of the steam injection pipeline, and the length of the steam injection pipeline; and determining the carbon emissions and energy consumption generated by the boiler steam production supplementary heat loss in the steam injection pipeline link based on the pipeline heat loss and the steam enthalpy value.

[0065] We can assume that the heat transfer from the steam pipe to the insulation layer is approximately a steady-state process (where the unsteady-state heat transfer between the insulation layer and the atmosphere is negligible due to the thin pipe wall, small heat capacity influence, and constant air thermal resistance); and that pressure changes in the pipeline are not considered. The first series thermal resistance model is used to characterize the series relationship between the four layers of heat transfer resistance that the steam passes through sequentially along the ground pipeline during the process of transporting steam from the boiler to the wellhead. Specifically, this includes the convective heat transfer resistance of the liquid film layer, the conductive heat transfer resistance of the pipe wall, the conductive heat transfer resistance of the insulation layer, and the forced convective heat transfer resistance between the insulation layer and the atmosphere.

[0066] The liquid film layer convective heat transfer resistance characterizes the convective heat transfer resistance between steam and the inner wall of the pipe, and its magnitude depends on the steam velocity, steam properties, and pipe inner diameter. The pipe wall conductive heat transfer resistance characterizes the thermal conductivity of the steel pipe wall itself, and its magnitude depends on the pipe wall thickness and the thermal conductivity of the pipe wall material. The insulation layer conductive heat transfer resistance characterizes the insulation capacity of the external insulation material of the pipeline, and its magnitude depends on the insulation layer thickness and the thermal conductivity of the insulation material. The forced convection heat transfer resistance between the insulation layer and the atmosphere characterizes the convective heat transfer resistance between the outer surface of the insulation layer and the atmospheric environment, and its magnitude depends on the ambient wind speed, air temperature, and the outer surface temperature of the insulation layer. These four layers of thermal resistance are connected in series according to the heat transfer path, forming a complete resistance chain for heat transfer from the steam inside the pipe to the external atmospheric environment.

[0067] The total thermal resistance of the steam injection pipeline can be determined based on the first series thermal resistance model. The total thermal resistance equals the sum of the convective heat transfer resistance of the liquid film layer, the conductive heat transfer resistance of the pipe wall, the conductive heat transfer resistance of the insulation layer, and the forced convection heat transfer resistance between the insulation layer and the atmosphere. The thermal resistance of each layer is calculated using the cylindrical wall thermal resistance formula in heat transfer theory. For solid media such as the pipe wall and insulation layer, the thermal resistance is directly proportional to the thickness of the medium and inversely proportional to the thermal conductivity and heat transfer area. For the liquid film layer and the outer convective layer, the thermal resistance is inversely proportional to the convective heat transfer coefficient and heat transfer area. Through the above calculations, the heat transfer characteristics of the multi-layered media are quantified into a comprehensive thermal resistance value, characterizing the heat conduction per unit length of pipeline under a unit temperature difference.

[0068] The pipeline heat loss can be determined based on the steam temperature, ambient temperature, total thermal resistance of the steam injection pipeline, and pipeline length. Specifically, the heat conduction per unit length of pipeline per unit time is calculated; this value equals the difference between the steam temperature and ambient temperature divided by the total thermal resistance of the pipeline. Multiplying the heat conduction per unit length of pipeline per unit time by the pipeline length and the operating time yields the total heat loss of the entire pipeline over a specified time period, expressed in kilojoules. The steam temperature is taken as the saturation temperature of the steam at the pipeline inlet, the ambient temperature is taken as the average atmospheric temperature along the pipeline route, and the operating time is determined based on the evaluation cycle.

[0069] Based on pipeline heat loss and steam enthalpy, the carbon emissions and energy consumption resulting from boiler steam production to compensate for heat loss in the steam injection pipeline process can be determined. This conversion process is based on the following principle: pipeline heat loss represents the heat energy lost by steam to the environment during transportation. To maintain the target enthalpy of the wellhead steam, the boiler needs to generate an additional amount of heat to compensate. Therefore, dividing the pipeline heat loss by the enthalpy of a unit mass of steam (the difference between the enthalpy of saturated steam and the enthalpy of feedwater) yields the amount of additional steam required to compensate for the heat loss. Multiplying this additional steam by the carbon emission intensity per ton of steam and the energy consumption intensity per ton of steam in the boiler steam production process gives the additional carbon emissions and energy consumption caused by pipeline heat loss. Through this conversion, the heat loss in the heat transfer process is quantified into carbon emission and energy consumption indicators that can be included in the overall process evaluation.

[0070] By constructing a four-layer series thermal resistance structure, the complex heat transfer process of ground pipelines is decomposed into thermal resistance units with clear physical meaning, achieving precise quantification of pipeline heat loss. Compared with traditional methods that use simplified heat transfer coefficients or empirical heat loss rates, this model can distinguish the contribution of different heat transfer links to the total thermal resistance, providing a basis for the optimized design of pipeline insulation structures. Simultaneously, by converting heat loss into carbon emissions and energy consumption through enthalpy, a quantitative correlation between the heat transfer process and energy consumption is established. This extends the evaluation at the injection end from simple heat loss to the actual impact of carbon emissions and energy consumption, laying the foundation for refined evaluation of the entire process.

[0071] In some embodiments, the total thermal resistance of the steam injection pipeline is determined based on the first series thermal resistance model; the pipeline heat loss is determined based on the steam temperature, ambient temperature, total thermal resistance of the steam injection pipeline, and length of the steam injection pipeline; and the carbon emissions and energy consumption generated by the boiler steam production heat loss in the steam injection pipeline are determined based on the pipeline heat loss and steam enthalpy. Specifically, this may further include: Calculate the heat conduction per unit time and length of pipeline using the following formula: In the formula, The steam temperature is in °C. Atmospheric temperature, °C; The total thermal resistance of the pipeline is expressed in m·K / W. The thermal conductivity is W / (m·K); Let be the outer radius of the pipeline, in meters (m). Let be the inner radius of the pipeline, in meters (m).

[0072] The convective heat transfer resistance of the liquid film layer is calculated using the following formula: In the formula, The convective heat transfer coefficient of the liquid film layer is W / (m²). 2 ·K); Let be the inner radius of the pipeline, in meters. Wherein, It characterizes the strength of convective heat transfer between steam and the inner wall of the pipe, and its value depends on the steam velocity, steam properties and pipe inner diameter. Characterizes the inner diameter of the steam flow channel.

[0073] The above formula is based on the definition of convective heat transfer resistance of a cylindrical wall, reflecting the convective heat transfer resistance per unit area of ​​the inner wall of the tube.

[0074] Calculate the thermal resistance of the tube wall using the following formula: In the formula, Where is the thermal conductivity of the pipe wall, W / (m·K); Let be the outer radius of the pipeline, in meters (m). Let be the inner radius of the pipeline, in meters. Wherein, Characterizes the heat conduction ability of the pipe wall material; Characterizes the radial dimension of the outer edge of the pipe wall.

[0075] The above formula is derived based on the thermal resistance of the cylindrical wall, reflecting the thermal resistance when heat passes radially through the pipe wall.

[0076] Calculate the thermal resistance of the insulation layer using the following formula: In the formula, The thermal conductivity of the insulation material is expressed in W / (m·K). Let the outer radius of the insulation layer be m; Let be the outer radius of the pipeline, in meters. Wherein, Characterize the thermal insulation performance of thermal insulation materials; Characterizes the radial dimension of the outer edge of the insulation layer.

[0077] The above formula is based on the thermal resistance of the cylindrical wall, reflecting the thermal resistance when heat passes radially through the insulation layer.

[0078] The thermal resistance of the insulation layer to forced convection heat transfer between the insulation layer and the atmosphere is calculated using the following formula: In the formula, The heat transfer coefficient between the outer surface of the insulation layer and the atmosphere is W / (m²). 2 ·K); Let be the outer radius of the insulation layer, in meters. Wherein, It characterizes the strength of convective heat transfer between the outer surface of the insulation layer and the atmospheric environment, and its value depends on the ambient wind speed, air temperature and the temperature of the outer surface of the insulation layer.

[0079] The above formula is based on the definition of convective heat transfer resistance of a cylindrical wall, reflecting the convective heat transfer resistance per unit area on the outer surface of the insulation layer.

[0080] Calculate the total thermal resistance of the pipe using the following formula: In the formula, The thermal resistance for convective heat transfer in the liquid film layer is m·K / W; The thermal resistance of the pipe wall is m·K / W; Thermal resistance of the insulation layer, m·K / W; The thermal resistance for forced convection heat transfer between the insulation layer and the atmosphere is given in m·K / W.

[0081] The above formula is based on the principle of superposition of series thermal resistance, which characterizes the complete resistance chain through which heat is transferred from the steam inside the pipe to the outside atmosphere.

[0082] Calculate the heat loss of the pipeline using the following formula: In the formula, Heat conduction per unit time and length of transport pipeline, in W / m; The length of the pipe is in meters (m). The total steam injection time is in seconds.

[0083] The above formula multiplies the heat conduction per unit time and unit length by the pipe length and the total steam injection time to obtain the total heat loss of the entire pipeline within a specified time period.

[0084] Calculate the heat of steam at the boiler steam-generating end using the following formula: In the formula, The enthalpy of saturated steam is expressed in kJ / kg. The steam conversion rate at the boiler steam generation end is expressed in tons (t).

[0085] The above formula represents the total thermal energy contained in the steam at the boiler outlet.

[0086] Calculate the remaining steam at the wellhead using the following formula: In the formula, The heat of steam at the boiler steam-generating end is expressed in kJ. The heat loss of the pipeline is expressed in kJ. The enthalpy of saturated steam is expressed in kJ / kg.

[0087] The above formula is based on the law of conservation of energy. After subtracting the heat loss of the pipeline from the heat of the steam at the boiler outlet, the formula is divided by the enthalpy of the steam to obtain the mass of the remaining steam at the wellhead.

[0088] The cumulative carbon emissions at the wellhead are calculated using the following formula: In the formula, Carbon emissions at the boiler steam generation end, in tons; The heat loss of the pipeline is expressed in kJ. The enthalpy of saturated steam is expressed in kJ / kg. Carbon emissions per ton of steam produced by the boiler.

[0089] The above formula adds the original carbon emissions at the boiler end to the carbon emissions generated by the additional steam required to compensate for pipeline heat loss, thus obtaining the cumulative carbon emissions at the wellhead.

[0090] Calculate the cumulative energy consumption at the wellhead using the following formula: In the formula, Energy consumption at the boiler steam generation end, GJ; The heat loss of the pipeline is expressed in kJ. The enthalpy of saturated steam is expressed in kJ / kg. Energy consumption per ton of steam at the boiler steam generation end.

[0091] The above formula adds the original energy consumption at the boiler end to the energy consumption generated by the additional steam required to compensate for pipeline heat loss, thus obtaining the cumulative energy consumption at the wellhead.

[0092] Calculate the carbon emissions per ton of steam at the wellhead using the following formula: In the formula, The cumulative carbon emissions at the wellhead, in tons (t). Let be the residual steam at the wellhead, in tons (t). Here, carbon emissions per ton of steam at the wellhead represent the carbon emission intensity corresponding to a unit mass of steam reaching the wellhead.

[0093] Calculate the energy consumption per ton of steam at the wellhead using the following formula: In the formula, Energy consumption accumulated at the wellhead, GJ; Let be the residual steam at the wellhead, in tons (t). Here, the energy consumption per ton of steam at the wellhead represents the energy intensity corresponding to a unit mass of steam reaching the wellhead.

[0094] The above formulas establish a quantitative system for the entire heat loss path from boiler to wellhead. Each layer of thermal resistance formula corresponds to a different heat transfer medium and mechanism, decomposing the complex multi-medium heat transfer problem into independently calculable units, thus providing a clear physical basis for determining thermal resistance. The series superposition of the total pipeline thermal resistance conforms to the actual heat transfer path, avoiding errors that might be introduced by the simplified equivalent thermal resistance method. The heat loss calculation uses the product of heat conduction per unit time and unit length with pipeline length and operating time, adapting to evaluation needs for different transport distances and operating cycles. The calculation of residual steam at the wellhead, cumulative carbon emissions, and cumulative energy consumption is based on energy conservation and mass balance. The heat loss is converted into equivalent steam volume using the steam enthalpy value, and then multiplied by the carbon emission intensity and energy consumption intensity per ton of steam, establishing a quantitative correlation between the heat transfer process and carbon emissions. These formulas provide a complete mathematical expression for refined evaluation at the injection end, enabling quantitative traceability of the impact of pipeline heat loss on the entire process's carbon emissions and energy consumption.

[0095] In some embodiments, the aforementioned series thermal resistance model includes a second series thermal resistance model; the second series thermal resistance model is used to characterize the series relationship between the thermal resistance of the steam injection pipe wall, the thermal resistance of the insulation layer, the annular convection heat transfer resistance, the annular radiation heat transfer resistance, the thermal resistance of the casing wall, the thermal resistance of the cement sheath, and the thermal resistance of the formation. Based on this, step S101 may further include: determining the total thermal resistance of the wellbore based on the second series thermal resistance model; determining the heat loss of the wellbore based on the steam injection temperature, the formation temperature, the total thermal resistance of the wellbore, the formation thermal resistance, and the well depth; and determining the carbon emissions and energy consumption generated by the boiler steam production supplementary heat loss in the steam injection wellbore stage based on the heat loss of the wellbore and the steam enthalpy value.

[0096] Considering the gradual increase in formation thermal resistance over time, based on the unsteady heat transfer theory, the formation thermal resistance can be calculated. The heat conduction of the wellbore is obtained by calculating the total thermal resistance, and then the heat loss and heat loss rate of the wellbore are obtained by combining the wellbore depth and steam injection time. Then, the carbon emissions and energy consumption generated by the boiler steam production to make up for the heat loss of the wellbore are calculated.

[0097] It can be assumed that: the annulus is filled with air or nitrogen; the heat transfer process from the steam injection pipe to the outside of the cement sheath is approximately steady-state; the heat transfer process from the cement sheath to the formation is approximately unsteady-state; and pressure changes in the wellbore are not considered. The second series thermal resistance model is used to characterize the series relationship between the six layers of heat transfer resistance that the steam passes through sequentially along the wellbore during the process of steam injection from the wellhead to the bottom of the well. Specifically, these include the thermal resistance of the steam injection pipe wall, the thermal resistance of the insulation layer, the convective heat transfer resistance of the annulus, the radiative heat transfer resistance of the annulus, the thermal resistance of the casing wall, the thermal resistance of the cement sheath, and the thermal resistance of the formation.

[0098] Among them, the thermal resistance of the steam injection pipe wall represents the thermal resistance between the injected steam and the steel pipe wall of the insulation layer, and its magnitude depends on the thickness of the steam injection pipe wall and the thermal conductivity of the pipe wall material. The thermal resistance of the insulation layer represents the insulation capacity of the external insulation material of the steam injection pipe, and its magnitude depends on the insulation layer thickness and the thermal conductivity of the insulation material. The annular convection heat transfer resistance represents the heat transfer resistance of the natural convection of gas (usually air or nitrogen) in the annulus, and its magnitude depends on the annular clearance, gas properties, and temperature difference. The annular radiation heat transfer resistance represents the radiation heat transfer resistance between the high-temperature and low-temperature surfaces in the annulus, and its magnitude depends on the surface emissivity, temperature, and geometry. The casing wall thermal resistance represents the thermal resistance of the casing steel wall itself, and its magnitude depends on the casing wall thickness and the thermal conductivity of the casing material. The cement sheath thermal resistance represents the thermal resistance of the cement sheath, and its magnitude depends on the cement sheath thickness and the thermal conductivity of the cement material. Formation thermal resistance characterizes the resistance to heat transfer from the outer edge of the cement sheath to the infinite formation. Based on unsteady-state heat transfer theory, its value increases with steam injection time. The above seven thermal resistances are connected in series according to the heat transfer path, forming a complete resistance chain for heat transfer from steam inside the wellbore to the external formation.

[0099] The total thermal resistance of the wellbore can be determined based on the second series thermal resistance model. The total thermal resistance equals the sum of the thermal resistance of the injection pipe wall, the insulation layer, the annular convection heat transfer, the annular radiation heat transfer, the casing wall, the cement sheath, and the formation. The formation thermal resistance is calculated using a non-steady-state heat transfer model. The thermal resistance of each layer is calculated using the cylindrical wall thermal resistance formula in heat transfer theory. For solid media such as the pipe wall, insulation layer, casing wall, and cement sheath, the thermal resistance is directly proportional to the media thickness and inversely proportional to the thermal conductivity and heat transfer area. For annular convection and radiation heat transfer, the thermal resistance is inversely proportional to the heat transfer coefficient and heat transfer area. For the formation, the thermal resistance is determined using the infinite medium heat transfer model in non-steady-state heat transfer theory and is related to the square root of time. Through the above calculations, the heat transfer characteristics of the multi-layered media in the wellbore are quantified into a comprehensive thermal resistance value, characterizing the heat conduction per unit depth of the wellbore under a unit temperature difference.

[0100] The heat loss of the wellbore can be determined based on the steam injection temperature, formation temperature, total thermal resistance of the wellbore, formation thermal resistance, and well depth. Specifically, the heat conduction per unit time per unit depth of the wellbore is calculated, which is equal to the difference between the steam injection temperature and the formation temperature divided by the total thermal resistance of the wellbore. The steam injection temperature is taken as the saturation temperature of the steam at the wellhead, and the formation temperature is determined based on the actual geothermal gradient as it varies with depth. However, the formation thermal resistance increases with the duration of steam injection, causing the heat conduction to decrease over time. Multiplying the heat conduction per unit time per unit depth by the well depth and the operating time yields the total heat loss of the entire wellbore over a specified period, expressed in kilojoules.

[0101] Based on the wellbore heat loss and steam enthalpy, the carbon emissions and energy consumption resulting from the boiler's supplementary steam production heat loss in the steam injection well process can be determined. This conversion process is consistent with the pipeline process: wellbore heat loss represents the heat energy lost by steam to the formation during injection. To maintain the target enthalpy for the steam at the bottom of the well, the boiler needs to generate an additional amount of heat to compensate. Therefore, dividing the wellbore heat loss by the enthalpy per unit mass of steam yields the amount of additional steam required to compensate for the heat loss; multiplying this additional steam by the carbon emission intensity per ton of steam and the energy consumption intensity per ton of steam in the boiler steam production process gives the additional carbon emissions and energy consumption due to wellbore heat loss. Through this conversion, the heat loss during the wellbore heat transfer process is quantified into carbon emission and energy consumption indicators that can be included in the overall process evaluation.

[0102] By constructing a seven-layer series thermal resistance structure incorporating formation unsteady thermal resistance, the complex heat transfer process in the wellbore is decomposed into thermal resistance units with clear physical meaning, achieving precise quantification of wellbore heat loss. Compared with traditional methods using simplified equivalent heat transfer coefficients, this model can distinguish the contribution of different heat transfer links to the total thermal resistance. In particular, by modeling annular convection and radiation separately, it fully considers the dual mechanism of gas heat transfer within the annulus, adapting to the radiative heat transfer characteristics of high-temperature wellbores in heavy oil thermal recovery. Simultaneously, the introduction of cement sheath thermal conductivity resistance incorporates the impact of cementing quality on heat transfer into the evaluation system, while the introduction of formation unsteady thermal resistance reflects the increase in thermal resistance caused by formation heating effects during long-term steam injection, providing a quantitative basis for optimizing wellbore insulation structures and improving cementing processes. By converting heat loss into carbon emissions and energy consumption, a quantitative correlation between the wellbore heat transfer process and energy consumption is established, extending the evaluation at the injection end from simple heat loss to the actual impact of carbon emissions and energy consumption, providing key technical support for refined evaluation of the entire process.

[0103] In some embodiments, the total thermal resistance of the wellbore is determined based on the second series thermal resistance model; the heat loss of the wellbore is determined based on the steam injection temperature, formation temperature, total thermal resistance of the wellbore, formation thermal conductivity, and well depth; and the carbon emissions and energy consumption generated by the boiler steam production supplementary heat loss in the steam injection wellbore stage are determined based on the heat loss of the wellbore and the steam enthalpy. Specifically, this may further include: The heat conduction per unit time and length of wellbore is calculated using the following formula: In the formula, The steam injection temperature is in °C. Formation temperature, °C; The total thermal resistance of the wellbore is expressed in m·K / W. The thermal resistance of the formation is expressed in m·K / W.

[0104] The above formula is based on Fourier's heat transfer law, which states that the heat conduction per unit time and unit depth is equal to the difference between the injection temperature and the formation temperature divided by the total thermal resistance of the wellbore and the thermal resistance of the formation.

[0105] Calculate the total thermal resistance using the following formula: In the formula, The thermal conductivity of the steam injection pipe is W / (m·K); The thermal conductivity of the insulation layer is W / (m·K); The thermal conductivity of the sleeve is W / (m·K); is the thermal conductivity of the cement ring, W / (m·K); Let be the inner radius of the steam injection pipe, in meters (m). Let be the outer radius of the steam injection pipe, in meters (m). Let be the inner radius of the insulation layer, in meters. Let be the outer radius of the insulation layer, in meters (m). Let be the inner radius of the casing, in meters (m). Let be the outer radius of the casing, in meters (m). Let the outer radius of the cement ring be m; is the annular natural convection coefficient, W / (m²·K); is the radiative heat transfer coefficient, W / (m²·K). Wherein, Characterizes the heat conduction capacity of the steam injection pipe wall material; Characterizing the inner diameter of the steam flow channel; This represents the radial dimension of the outer edge of the steam injection pipe wall. The first term in the above formula is the thermal resistance of the steam injection pipe wall, derived from the formula for the thermal conductivity of a cylindrical wall, reflecting the thermal resistance as heat passes radially through the steam injection pipe wall. This characterizes the ability of thermal insulation materials to conduct heat. The second term in the above formula represents the thermal resistance of the insulation layer, reflecting the resistance to heat conduction as it passes radially through the insulation layer. It characterizes the heat transfer intensity of natural convection of gas within the annulus, and its value depends on the annular space, gas properties, and temperature difference; The strength of radiative heat transfer between high-temperature and low-temperature surfaces within the annulus is characterized by its value, which depends on surface emissivity, temperature, and geometry. The third term in the above formula represents the total thermal resistance of annular convection and radiation heat transfer. It is presented in parallel, combining the two heat transfer mechanisms to reflect the overall resistance to heat transfer within the annulus. This characterizes the heat conduction capability of the casing wall material. The fourth term in the above formula represents the thermal resistance of the casing wall, reflecting the resistance to heat conduction radially through the casing wall. This characterizes the heat conduction capacity of the cement sheath material. The fifth term in the above formula represents the thermal resistance of the cement sheath, reflecting the resistance to heat conduction radially through it.

[0106] The aforementioned thermal resistances are connected in series according to the heat transfer path, constituting the total thermal resistance of the wellbore. This formula fully describes all heat transfer stages from the steam inside the wellbore to the external formation.

[0107] Calculate the thermal resistance of the formation using the following formula: In the formula, The thermal resistance of the formation is expressed in m·K / W. is the thermal conductivity of the formation, W / (m·K); It is the dimensionless formation thermal conductivity time coefficient.

[0108] The dimensionless formation thermal conductivity time coefficient can be achieved using the Hasan model: In the formula, The thermal conductivity time coefficient of the dimensionless formation; m is the thermal diffusivity of the formation. 2 / s; The steam injection time is in seconds. The outer radius of the cement ring (m) is the starting radius from which heat enters the formation from the wellbore.

[0109] Logarithmic mean heat loss rate: In the formula, The heat loss rate at the initial moment (i.e., 1 second) is expressed in W / m. The final time is W / m.

[0110] Calculate the heat loss of the wellbore using the following formula: In the formula, Heat conduction per unit time and length of wellbore, expressed in W / m; Let the depth be m; The total steam injection time is in seconds.

[0111] The above formula multiplies the heat conduction per unit time and unit depth by the well depth and the total steam injection time to obtain the total heat loss of the entire wellbore within a specified time period.

[0112] Calculate the residual steam heat at the wellhead using the following formula: In the formula, The heat of steam at the boiler steam-generating end is expressed in kJ. The value is the heat loss of the pipeline, expressed in kJ.

[0113] The above formula is based on the law of conservation of energy. It subtracts the heat loss of the ground pipeline from the heat of the steam at the boiler outlet to obtain the heat carried by the steam entering the well.

[0114] Calculate the remaining steam at the bottom of the well using the following formula: In the formula, The residual steam heat at the wellhead, kJ; The heat loss of the wellbore is expressed in kJ. The enthalpy of saturated steam is expressed in kJ / kg.

[0115] The above formula is based on the law of conservation of energy. After subtracting the heat loss of the wellbore from the heat of the steam at the wellhead, it is divided by the enthalpy of the steam to obtain the mass of the remaining steam at the bottom of the well.

[0116] The cumulative carbon emissions at the bottom of the well are calculated using the following formula: In the formula, The cumulative carbon emissions at the wellhead, in tons (t). The heat loss of the wellbore is expressed in kJ. The enthalpy of saturated steam is expressed in kJ / kg. This represents the carbon emissions per ton of steam at the wellhead.

[0117] The above formula adds the cumulative carbon emissions at the wellhead to the carbon emissions generated by the additional steam required to compensate for the heat loss in the wellbore, and obtains the cumulative carbon emissions at the bottom of the well.

[0118] The cumulative energy consumption at the bottom of the well is calculated using the following formula: In the formula, Energy consumption accumulated at the wellhead, GJ; The heat loss of the wellbore is expressed in kJ. The enthalpy of saturated steam is expressed in kJ / kg. This represents the energy consumption per ton of steam at the wellhead.

[0119] The above formula adds the cumulative energy consumption at the wellhead to the energy consumption generated by the additional steam required to compensate for the heat loss in the wellbore, and obtains the cumulative energy consumption at the bottom of the well.

[0120] Calculate the carbon emissions per ton of steam at the bottom of the well using the following formula: In the formula, The cumulative carbon emissions at the bottom of the well, in tons; Let be the residual steam at the bottom of the well, in tons (t). Here, the carbon emission per ton of steam at the bottom of the well represents the carbon emission intensity corresponding to a unit mass of steam reaching the bottom of the well.

[0121] Calculate the energy consumption per ton of steam at the bottom of the well using the following formula: In the formula, Energy consumption accumulated at the bottom of the well, GJ; Let be the remaining steam at the bottom of the well, expressed in tons (t). Here, the energy consumption per ton of steam at the bottom of the well represents the energy intensity corresponding to a unit mass of steam reaching the bottom of the well.

[0122] The above formulas establish a complete quantitative system for wellbore heat loss from wellhead to bottom. The total thermal resistance formula models each of the six heat transfer layers of the wellbore. The steam injection pipe wall, insulation layer, casing wall, and cement sheath are modeled using a cylindrical wall thermal conductivity model, while the annulus uses a parallel convection and radiation thermal resistance model, comprehensively covering all key aspects of wellbore heat transfer. Compared to traditional methods using a single equivalent heat transfer coefficient, this model can distinguish the contribution of different heat transfer media to the total thermal resistance, especially by modeling annular convection and radiation separately, fully considering the dominant role of radiation heat transfer under high-temperature wellbore conditions. The calculation of bottom-hole residual steam, cumulative carbon emissions, and cumulative energy consumption is based on energy conservation and mass balance. The wellbore heat loss is converted into equivalent steam volume using the steam enthalpy value, and then multiplied by the corresponding ton-of-steam index, establishing a quantitative correlation between the wellbore heat transfer process and carbon emissions. The above formula provides a complete mathematical expression for the refined evaluation of the injection end, making the impact of wellbore heat loss on the carbon emissions and energy consumption of the entire process quantitatively traceable, and providing a scientific basis for the optimization of wellbore insulation structure and the design of steam injection parameters.

[0123] In some embodiments, the aforementioned lift power model is used to characterize the conversion relationship between power consumption and hydraulic work, transmission system efficiency, and pump efficiency during the process of lifting the produced fluid from the bottom of the well to the wellhead. Based on this, step S102 may further include: determining the daily power consumption based on the lift power model; and determining the carbon emissions and energy consumption of the production well lift process based on the daily power consumption and the grid carbon emission factor.

[0124] The lift power model is used to characterize the conversion relationship between power consumption and hydraulic work, transmission system efficiency, and pump efficiency during the process of lifting produced fluid from the bottom of the well to the wellhead. Based on the principle of physical work, this model establishes a correlation between the theoretical minimum work required to lift the fluid against gravity and the actual power consumption, providing a quantitative basis for evaluating carbon emissions and energy consumption in the production well lift process.

[0125] Daily power consumption can be determined based on a lifting power model. This model converts theoretical hydraulic work into actual power consumption using efficiency parameters. Theoretical hydraulic work represents the minimum theoretical work required to overcome gravity to lift the produced fluid from the bottom of the well to the wellhead. Its calculation depends on three parameters: daily produced fluid mass, gravitational acceleration, and well depth. The daily produced fluid mass is determined by the product of the daily produced fluid rate and the density of the mixed fluid, representing the total mass of fluid extracted from the wellhead during the evaluation period. Gravitational acceleration is taken as a standard value of 9.8 m / s². Well depth represents the lifting height. The transmission system efficiency represents the efficiency of transmitting electrical energy input to mechanical energy output, and its value depends on the comprehensive performance of the motor, reducer, drive shaft, and other equipment. Pump efficiency represents the efficiency of the lifting equipment in converting mechanical energy into liquid potential energy, and its value depends on the pump type, operating conditions, and wear level. Dividing the theoretical hydraulic work by the product of the transmission system efficiency and the pump efficiency, and then converting the units, yields the actual daily power consumption.

[0126] Based on daily electricity consumption and the grid carbon emission factor, the carbon emissions and energy consumption of the lifting process in the production well can be determined. The grid carbon emission factor represents the carbon dioxide emissions corresponding to a unit of electricity consumption; its value depends on the power supply structure of the regional grid, and the unit is kilograms of carbon dioxide equivalent per kilowatt-hour. Daily carbon emissions equal daily electricity consumption multiplied by the grid carbon emission factor. Daily energy consumption is obtained directly through unit conversion; since 1 kilowatt-hour equals 3600 kilojoules, daily energy consumption equals daily electricity consumption multiplied by 3600, representing the total amount of electrical energy actually consumed in the lifting process.

[0127] By directly linking the energy consumption of the lifting process to the physical work done through a lifting power model, the crude method of relying solely on empirical coefficients for estimation is avoided. The calculation of theoretical hydraulic work is based on three fundamental physical quantities: mass, gravitational acceleration, and well depth, possessing clear physical meaning and objectivity. The introduction of transmission system efficiency and pump efficiency enables the model to reflect the actual energy consumption levels of different lifting processes (such as screw pumps, ESPs, and pumping units), providing a quantitative basis for energy-saving optimization of the lifting system. Simultaneously, the combination of daily power consumption and grid carbon emission factors converts electrical energy consumption into carbon emissions, achieving precise accounting of carbon emissions in the lifting process.

[0128] In some embodiments, the daily power consumption is determined based on the lifting power model; and the carbon emissions and energy consumption of the production well lifting process are determined based on the daily power consumption and the grid carbon emission factor. Specifically, this may further include: Calculate the daily liquid production mass using the following formula: In the formula, The daily liquid production rate, m 3 / d; The density of the mixed liquid is kg / m³. 3 .in, The total volume of fluid produced from the wellhead during the evaluation period is characterized by readings from field metering equipment or derived from reservoir numerical simulation results. The overall density characterizes the produced fluid. Since produced fluid is usually an oil-water mixture, this value is determined by a weighted calculation based on water content and oil-water density.

[0129] The above formula converts volumetric flow rate into mass flow rate, providing basic data for subsequent hydraulic work calculations.

[0130] The theoretical daily hydraulic work done by the lifted fluid is calculated using the following formula: In the formula, The quantity is the daily liquid production mass, kg / d; The acceleration due to gravity is m / s². 2 ; represents the well depth, in meters. Wherein, It represents the lifting height, which is the vertical distance from the bottom of the well to the wellhead.

[0131] The above formula is based on the fundamental principle of work done against gravity in physics, and calculates the work done against a mass of... Liquid lifting height The minimum theoretical work required. This theoretical work characterizes the lower limit of the ideal energy consumption of the lifting process, without considering various energy losses in the actual lifting system.

[0132] Calculate daily power consumption using the following formula: In the formula, Theoretical hydraulic work done by the sun, kJ / d; The overall efficiency of the transmission system is % Pump efficiency is expressed as %; 3600 is a unit conversion factor. It characterizes the transmission efficiency from electrical energy input to mechanical energy output, and its value is determined by the product of factors such as motor efficiency, reducer efficiency, and transmission shaft efficiency. The efficiency by which a lifting device converts mechanical energy into liquid potential energy depends on the pump type (such as screw pump, electric submersible pump, oil pumping unit, etc.), operating conditions, and the degree of equipment wear.

[0133] The above formula divides the theoretical hydraulic work by the product of the transmission system efficiency and the pump efficiency to obtain the actual electrical energy consumed, reflecting the true energy consumption level of the lifting process.

[0134] The daily carbon emissions from wellbore lift are calculated using the following formula: In the formula, Daily power consumption, kWh / d; The carbon emission factor for the power grid is kg CO2e / kWh.

[0135] The above formula multiplies the power consumption by the grid carbon emission factor to obtain the daily carbon emissions of the lifting process.

[0136] Calculate the daily energy consumption of wellbore lifting using the following formula: In the formula, Theoretical hydraulic work done by the sun, kJ / d; The overall efficiency of the transmission system is % For pump efficiency, %.

[0137] The above formula represents the total amount of energy actually consumed in the lifting process, which complements the calculation of carbon emissions.

[0138] The above five sets of formulas establish a complete quantitative chain from fluid production to lift energy consumption and carbon emissions. The calculation of daily fluid production mass and theoretical hydraulic work is based on three fundamental physical quantities: mass, gravitational acceleration, and well depth. This ensures objectivity and reproducibility, avoiding subjective biases inherent in empirical estimations. The introduction of transmission system efficiency and pump efficiency allows the model to differentiate the energy consumption characteristics of different lift processes and equipment, providing a quantitative basis for energy-saving optimization of the lift system. The introduction of the grid carbon emission factor links electricity consumption to carbon emissions, enabling the carbon emission assessment of the lift process to reflect differences in regional power structure.

[0139] In some embodiments, the aforementioned heat loss compensation model is used to characterize the temperature difference relationship between the wellbore average temperature and the formation temperature. Based on this, step S102 may further include: determining the daily heat loss of the wellbore based on the heat loss compensation model; and determining the carbon emissions and energy consumption of the wellbore heat tracing process based on the daily heat loss of the wellbore, boiler efficiency, and fuel carbon emission factor.

[0140] The heat loss compensation model is used to characterize the temperature difference between the wellbore average temperature and the formation temperature. Based on steady-state heat transfer theory, this model calculates the heat loss of the produced fluid to the formation during the wellbore ascent, and then converts it into the heat required to maintain the fluid temperature, providing a quantitative basis for evaluating carbon emissions and energy consumption in wellbore heating systems.

[0141] The daily heat loss of the wellbore can be determined based on a heat loss compensation model. This model establishes the temperature difference between the average wellbore temperature and the formation temperature, and calculates the heat loss using the wellbore thermal resistance. The average wellbore temperature is determined using a production-weighted average temperature method. Based on dynamic oil well production data, the bottom-hole temperatures corresponding to high, medium, and low daily production values ​​are obtained. Then, a weighted logarithmic sum is calculated based on the proportion of each production range to obtain the weighted logarithmic average wellbore temperature. The average formation temperature is taken as the median value between the reservoir temperature and the wellhead temperature, or calculated based on the geothermal gradient. The total wellbore thermal resistance is calculated using a second series thermal resistance model. This model considers the heat transfer path between the produced fluid and the formation, including multiple layers of thermal resistance such as pipe wall conduction, annular convection, casing conduction, and cement sheath conduction. The heat conduction per unit time per unit depth in the wellbore is equal to the difference between the average wellbore temperature and the average formation temperature divided by the total wellbore thermal resistance. Multiplying this heat conduction by the well depth and production time yields the daily heat loss of the wellbore, expressed in kilojoules per day.

[0142] Based on the daily heat loss of the wellbore, boiler efficiency, and fuel carbon emission factor, the carbon emissions and energy consumption of the wellbore heating system can be determined. The daily heat loss of the wellbore represents the heat energy lost by the produced fluid to the formation during the wellbore's ascent. To maintain the target wellhead temperature, an equivalent amount of heat needs to be replenished through the heating system. This heat is provided by the surface boiler. Therefore, dividing the daily heat loss of the wellbore by the boiler efficiency yields the heat released by fuel combustion required to compensate for the heat loss; dividing this heat by the lower heating value of the fuel yields the required fuel consumption. Carbon emissions equal fuel consumption multiplied by the fuel carbon content, carbon oxidation rate, and atomic weight conversion factor; energy consumption equals fuel consumption multiplied by the lower heating value of the fuel and boiler efficiency, or directly equals the daily heat loss of the wellbore divided by the boiler efficiency.

[0143] By dynamically linking the energy consumption of the wellbore heating process with the actual heat loss of the produced fluid through a heat loss compensation model, the crude method of estimating with fixed heating power is avoided. The introduction of the production-weighted average temperature method allows the calculation of bottom hole temperature to reflect the impact of production fluctuations on the wellbore temperature distribution, overcoming the bias caused by a single temperature assumption. The calculation of the temperature difference between the wellbore average temperature and the formation temperature, as well as the application of the total thermal resistance of the wellbore, provide a clear physical basis for determining the heat loss. By converting the heat loss into fuel consumption through boiler efficiency, and then calculating carbon emissions and energy consumption, a quantitative correlation between the wellbore heat transfer process and energy consumption is established.

[0144] In some embodiments, the daily heat loss of the wellbore is determined based on the heat loss compensation model; the carbon emissions and energy consumption of the wellbore heat tracing process are determined based on the daily heat loss of the wellbore, boiler efficiency, and fuel carbon emission factor. Specifically, this may further include: Calculate the bottom-hole temperature using the following formula: In the formula, , , The bottom hole temperatures (°C) correspond to high, medium, and low daily production values, respectively. , , These represent the weighted percentages corresponding to high, medium, and low daily output values, respectively.

[0145] The above formula uses a production-weighted average to ensure that the calculation of bottom hole temperature reflects the impact of actual production fluctuations on wellbore temperature distribution, thus overcoming the bias caused by a single temperature assumption.

[0146] The weighted logarithmic mean temperature of the wellbore is calculated using the following formula: In the formula, The bottom hole temperature is in °C. Set the target temperature at the wellhead, in °C.

[0147] The above formula takes a weighted logarithmic average of the bottom hole temperature and the target temperature at the wellhead to obtain the average temperature along the wellbore, which serves as the benchmark for subsequent heat loss calculations.

[0148] The heat conduction per unit time and length of wellbore is calculated using the following formula: In the formula, The average temperature of the wellbore is ℃; The average temperature of the formation is given in °C. The total thermal resistance of the wellbore is expressed in m·K / W.

[0149] The calculation is based on the second series thermal resistance model, comprehensively considering multiple layers of thermal resistance, including heat conduction through the pipe wall, annular convection, casing, and cement sheath between the produced fluid and the formation. The above formula is based on Fourier's law of heat transfer, where the heat conduction per unit time per unit depth equals the absolute temperature difference divided by the total thermal resistance.

[0150] Calculate the daily heat loss of the wellbore using the following formula: In the formula, The logarithmic average heat loss rate is expressed in W / m. t represents the well depth (m); t represents the production time (s).

[0151] The above formula multiplies the heat conduction per unit time and unit depth by the well depth and the time of day to obtain the total heat loss of the entire wellbore in one day.

[0152] Calculate the daily carbon emissions of wellbore heating using the following formula: In the formula, This represents the daily heat loss of the wellbore, expressed in kJ / d. The lower heating value of the fuel is kJ / kg; The carbon content of fuel, % , where % is the carbon oxidation rate; 3.67 is the atomic weight conversion factor. For boiler efficiency, %.

[0153] The above formula treats the heat loss of the well shaft as the heat that needs to be supplemented by the boiler, converts it into the heat released by fuel combustion through the boiler efficiency, divides it by the lower heating value of the fuel to obtain the fuel consumption, and finally multiplies it by the carbon content, carbon oxidation rate and conversion factor to obtain the carbon dioxide emissions.

[0154] Calculate the daily energy consumption of wellbore heating using the following formula: In the formula, This represents the daily heat loss of the wellbore, expressed in kJ / d. For boiler efficiency, %.

[0155] The above formula divides the heat loss of the well shaft by the boiler efficiency to obtain the heat released by fuel combustion required to compensate for the heat loss, which is the actual energy consumption of the well shaft heat tracing process.

[0156] By employing the production-weighted average temperature method, the calculation of bottom hole temperature can reflect the impact of actual production fluctuations on wellbore temperature distribution, overcoming the bias caused by a single temperature assumption and improving the accuracy of heat tracing load calculation. The calculation of the temperature difference between the wellbore average temperature and the formation average temperature, along with the application of the total thermal resistance of the wellbore, provides a clear physical basis for determining heat loss, avoiding the crudeness of empirical estimation. By progressively converting wellbore heat loss into carbon emissions and energy consumption using parameters such as boiler efficiency, lower heating value of fuel, and fuel carbon content, a quantitative correlation between the wellbore heat transfer process and energy consumption is established, making the carbon emissions and energy consumption of the heat tracing process quantitatively traceable.

[0157] In some embodiments, the energy consumption conversion model includes a first energy consumption conversion model; the first energy consumption conversion model is used to characterize the conversion relationship between the heat tracing energy required to maintain the flow of produced fluid in the surface pipeline and the fuel consumption. Based on this, step S102 may further include: determining the daily heat loss of the transport pipeline based on the first energy consumption conversion model; and determining the carbon emissions and energy consumption of the fluid gathering and transportation link based on the daily heat loss, boiler efficiency, and fuel carbon emission factor.

[0158] The first energy consumption conversion model is used to characterize the conversion relationship between the heating energy required to maintain the flow of produced fluid in surface pipelines and fuel consumption. During the transport of produced fluid from the wellhead to the processing station, the fluid continuously dissipates heat to the atmosphere due to the lower ambient temperature compared to the produced fluid temperature, causing the temperature to drop. When the temperature drops below the wax precipitation point or freezing point of crude oil, the fluid flowability deteriorates, and blockages may even occur. Therefore, a heating system (such as heat tracing pipes, electric heating tapes, or heaters) is needed to supplement heat and maintain the produced fluid temperature above the safe flow temperature. The first energy consumption conversion model can convert the heating energy required to maintain fluid flowability into fuel consumption, and then calculate the corresponding carbon emissions and energy consumption.

[0159] The daily heat loss of the transportation pipeline can be determined based on the first energy consumption conversion model. This process is based on steady-state heat transfer theory, constructing the surface pipeline as a multi-layered series thermal resistance structure, comprehensively considering multiple layers of thermal resistance, including convective heat transfer between the produced fluid and the pipe wall, heat conduction through the pipe wall, heat conduction through the insulation layer, and convective heat transfer on the outer surface of the insulation layer. The pipeline maintenance temperature refers to the minimum temperature set to ensure normal flow of the produced fluid; the ambient temperature is taken as the average atmospheric temperature along the pipeline route. By calculating the total thermal resistance of the pipeline and combining it with the difference between the maintenance temperature and the ambient temperature, the heat conduction per unit length of pipeline per unit time is obtained; multiplying this by the pipeline length and the duration of one day yields the daily heat loss of the transportation pipeline. This heat loss represents the amount of heat required to maintain the produced fluid temperature from decreasing.

[0160] Based on daily heat loss, boiler efficiency, and fuel carbon emission factor, the carbon emissions and energy consumption of the fluid gathering and transportation process can be determined. Daily heat loss is the additional heat required to maintain fluid flow, provided by a ground-mounted boiler or heating furnace. Dividing the daily heat loss by the boiler efficiency yields the heat released by fuel combustion required to compensate for the heat loss; dividing this heat by the lower heating value of the fuel yields the required fuel consumption. Carbon emissions equal fuel consumption multiplied by the fuel carbon content, carbon oxidation rate, and atomic weight conversion factor; energy consumption equals daily heat loss divided by boiler efficiency, or equals fuel consumption multiplied by the lower heating value of the fuel and boiler efficiency.

[0161] The first energy consumption conversion model dynamically correlates the heat tracing energy consumption in the fluid gathering and transportation process with the actual heat loss of the pipeline, avoiding the crude method of estimating with fixed heat tracing power. The pipeline heat loss calculation is based on a multi-layer series thermal resistance model, incorporating factors such as pipeline insulation structure and environmental conditions into the evaluation system, thus providing a clear physical basis for determining the heat loss. The heat loss is converted into fuel consumption through boiler efficiency, and then carbon emissions and energy consumption are calculated, establishing a quantitative correlation between the pipeline heat transfer process and energy consumption.

[0162] In some embodiments, the daily heat loss of the transport pipeline is determined based on the first energy consumption conversion model; the carbon emissions and energy consumption of the fluid gathering and transportation process are determined based on the daily heat loss, boiler efficiency, and fuel carbon emission factor, and may further include: The heat conduction per unit length of transport pipeline is calculated using the following formula: In the formula, To maintain the temperature of the ground pipelines, ℃; Atmospheric temperature, °C; The total thermal resistance of the ground pipeline is expressed in m·K / W.

[0163] The above formula is based on Fourier's law of heat transfer, which states that the amount of heat conducted per unit time per unit length is equal to the difference between the operating temperature and the ambient temperature divided by the total thermal resistance of the pipeline.

[0164] Calculate the daily heat loss of the transport pipeline using the following formula: In the formula, Heat conductivity per unit length of transport pipeline, W / m; t represents the pipeline length (m); t represents the production time (s). This heat loss represents the amount of heat required to maintain the produced fluid temperature.

[0165] The daily carbon emissions of transport pipelines are calculated using the following formula: In the formula, This represents the daily heat loss of the transportation pipeline, expressed in kJ / d. The lower heating value of the fuel is kJ / kg; The carbon content of fuel, % , where % is the carbon oxidation rate; 3.67 is the atomic weight conversion factor. For boiler efficiency, %.

[0166] The above formula treats the daily heat loss of the pipeline as the heat that needs to be supplemented by the boiler, converts it into the heat released by fuel combustion through the boiler efficiency, divides it by the lower heating value of the fuel to obtain the fuel consumption, and finally multiplies it by the carbon content, carbon oxidation rate and conversion factor to obtain the carbon dioxide emissions.

[0167] Calculate the daily energy consumption of the transportation pipeline using the following formula: In the formula, This represents the daily heat loss of the transportation pipeline, expressed in kJ. For boiler efficiency, %.

[0168] The above formula divides the daily heat loss of the pipeline by the boiler efficiency to obtain the heat released by fuel combustion required to compensate for the heat loss, which is the actual energy consumption of the fluid gathering and transportation process.

[0169] The first energy consumption conversion model dynamically correlates the heat tracing energy consumption in the fluid gathering and transportation process with the actual heat loss of the pipeline, avoiding the crude method of estimating with fixed heat tracing power. The pipeline heat loss calculation is based on a multi-layer series thermal resistance model, incorporating factors such as pipeline insulation structure and environmental conditions into the evaluation system, thus providing a clear physical basis for determining the heat loss. The heat loss is then progressively converted into carbon emissions and energy consumption using parameters such as boiler efficiency, lower heating value of fuel, and fuel carbon content, establishing a quantitative correlation between the pipeline heat transfer process and energy consumption.

[0170] In some embodiments, the energy consumption conversion model includes a second energy consumption conversion model; the second energy consumption conversion model is used to characterize the conversion relationship between the heat required for oil-water separation and crude oil dehydration processes and fuel consumption. Based on this, step S102 may further include: determining the daily fuel consumption required for oil-water separation based on the second energy consumption conversion model; and determining the carbon emissions and energy consumption of the ground treatment process based on the daily fuel consumption, fuel carbon content, carbon oxidation rate, boiler efficiency, and fuel calorific value.

[0171] The second energy consumption conversion model is used to characterize the conversion relationship between the heat required for oil-water separation and crude oil dehydration processes and fuel consumption. Oil-water separation and crude oil dehydration are core processes in surface processing. They involve heating the produced fluid to separate the oil and water phases due to their density difference, and removing emulsified water from the crude oil to meet export standards. The heat required for this process is provided by surface boilers or heaters. Therefore, the core function of the second energy consumption conversion model is to convert the heat requirements of the separation process into fuel consumption, and then calculate the corresponding carbon emissions and energy consumption.

[0172] The daily fuel consumption required for oil-water separation can be determined based on the second energy consumption conversion model. The heat required for oil-water separation is calculated based on the sensible heat required to raise the fluid temperature. The daily produced liquid mass is determined by the product of the daily produced liquid rate and the density of the mixed liquid, representing the total mass of produced liquid entering the treatment plant. The specific heat capacity of the liquid represents the heat required to raise the temperature by a unit mass of liquid; for oil-water mixtures, it is calculated by weighting the specific heat capacity of oil and water according to the water content. The difference between the target temperature for oil-water separation and the temperature maintained by the ground pipeline represents the temperature rise required by the treatment process. The product of the above three items is the daily heat required for oil-water separation. Dividing this daily heat by the product of the boiler efficiency and the lower heating value of the fuel yields the daily fuel consumption required to provide this heat. The boiler efficiency reflects the effective proportion of fuel combustion heat converted into process heat, and the lower heating value of the fuel represents the heat released by the complete combustion of a unit mass of fuel.

[0173] Based on daily fuel consumption, fuel carbon content, carbon oxidation rate, boiler efficiency, and lower heating value of the fuel, the carbon emissions and energy consumption of the surface treatment process can be determined. Carbon emissions are calculated according to the carbon mass balance principle: daily fuel consumption multiplied by fuel carbon content yields the mass of carbon in the fuel, which is then multiplied by the carbon oxidation rate to obtain the mass of carbon elements oxidized, and finally multiplied by the atomic weight conversion factor of 3.67 to obtain the mass of carbon dioxide emitted. Energy consumption is calculated directly to reflect the energy consumption of the process: daily fuel consumption multiplied by the lower heating value of the fuel, then multiplied by the boiler efficiency, yields the effective heat actually used for heating; alternatively, the daily heat required for oil-water separation is directly divided by the boiler efficiency to obtain the total heat released by boiler fuel combustion. The results of both methods are equivalent and both characterize the actual energy consumption of the surface treatment process.

[0174] A second energy consumption conversion model establishes a quantitative correlation between the heat demand and fuel consumption of the oil-water separation process, providing a clear physical basis for evaluating carbon emissions and energy consumption in the surface treatment stage. Compared with estimation methods using fixed energy consumption coefficients, this model can dynamically adjust the calculation results according to the actual treatment volume, fluid properties, and process temperature requirements, reflecting the differences in treatment energy consumption under different operating conditions. The introduction of liquid specific heat capacity takes into account the impact of produced fluid water content on heat capacity, making the heat calculation closer to reality; the introduction of boiler efficiency distinguishes the difference between fuel combustion and heat utilization, enabling energy consumption calculations to reflect the true primary energy consumption.

[0175] In some embodiments, the daily fuel consumption required for oil-water separation is determined based on the second energy consumption conversion model; the carbon emissions and energy consumption of the ground treatment process are determined based on the daily fuel consumption, fuel carbon content, carbon oxidation rate, boiler efficiency, and fuel calorific value, and may further include: Calculate the daily heat required for oil-water separation using the following formula: In the formula, The quantity is the daily liquid production mass, kg / d; Specific heat capacity of liquid, kJ / kg·℃; Set the target temperature for oil-water separation, in °C; To maintain the temperature of the ground pipeline, ℃.

[0176] The above formula is based on the principle of sensible heat calculation. It multiplies the liquid mass, specific heat capacity and temperature rise by the amount of heat required to heat the produced liquid from the maintenance temperature to the separation temperature.

[0177] Calculate daily fuel consumption using the following formula: In the formula, The daily heat required for oil-water separation, kJ / d; The lower heating value of the fuel is kJ / kg; For boiler efficiency, %.

[0178] The above formula treats the heat required for oil-water separation as the effective heat output of the boiler, and divides it by the boiler efficiency and the lower heating value of the fuel to obtain the required fuel consumption.

[0179] Calculate daily carbon emissions from ground treatment using the following formula: In the formula, This refers to the daily fuel consumption, in tons per day (t / d). The carbon content of fuel, % , where is the carbon oxidation rate, %; and 3.67 is the atomic weight conversion factor.

[0180] The above formula is based on the principle of carbon mass balance. It multiplies the fuel consumption by the carbon content, carbon oxidation rate and conversion factor to obtain the carbon dioxide emission mass.

[0181] Calculate the daily energy consumption for ground processing using the following formula: In the formula, The mass of fuel, t / d; The lower heating value of the fuel is kJ / kg; For boiler efficiency, %.

[0182] The above formula calculates the actual amount of primary energy consumed in the ground processing stage, that is, the heat energy released by fuel combustion and effectively utilized.

[0183] The above four sets of formulas establish a quantitative correlation between the heat demand, fuel consumption, and carbon emissions of oil-water separation processes. The daily heat demand calculation for oil-water separation is based on the sensible heat principle, considering throughput, fluid properties, and process temperature requirements, and can dynamically reflect changes in energy consumption under different operating conditions. The specific heat capacity of the liquid is calculated using a weighted average based on water content, making the heat calculation more closely reflect the actual physical properties of the produced fluid. The daily fuel consumption calculation incorporates boiler efficiency, distinguishing between fuel combustion and heat utilization, ensuring that the energy consumption calculation reflects the true primary energy consumption. The carbon emission calculation uses atomic weight conversion factors to accurately convert the mass of carbon in the fuel into the mass of carbon dioxide.

[0184] In some embodiments, the energy consumption conversion model includes a third energy consumption conversion model; the third energy consumption conversion model is used to characterize the conversion relationship between the electricity consumption and carbon emissions required for the carbon dioxide capture, compression, and injection underground storage system. Based on this, step S102 may further include: determining the daily power consumption of the reinjection system based on the third energy consumption conversion model; determining the daily carbon emissions and daily energy consumption of the reinjection system based on the daily power consumption; determining the direct escaping carbon emissions based on the difference between the total escaping carbon emissions and the recovered reinjected carbon emissions; and determining the carbon emissions and energy consumption of the escaping reinjection stage based on the daily carbon emissions, daily energy consumption, and direct escaping carbon emissions of the reinjection system.

[0185] The third energy consumption conversion model is used to characterize the conversion relationship between the electricity consumption and carbon emissions required for carbon dioxide capture, compression, and injection into underground storage systems. During heavy oil thermal recovery, produced fluids release associated gases, including greenhouse gases such as carbon dioxide, during processing. Direct release into the atmosphere results in fugitive carbon emissions; while capture, compression, and reinjection into the formation for storage reduces direct emissions, it still consumes electricity, generating indirect carbon emissions. The core function of the third energy consumption conversion model is to establish a quantitative relationship between electricity consumption and carbon emissions in the capture and reinjection process, and, combined with fugitive carbon emissions, comprehensively evaluate the net carbon emissions of the fugitive reinjection stage.

[0186] The daily power consumption of the reinjection system can be determined based on the third energy consumption conversion model. The daily power consumption of the reinjection system depends on the amount of carbon dioxide recovered and reinjected, and the power consumption coefficient of the reinjection system. The amount of carbon dioxide recovered and reinjected is calculated using total volatile carbon emissions (TVE), carbon capture efficiency (CFA), and storage efficiency. TVE is determined based on the daily produced liquid mass and the average crude oil loss rate. The average crude oil loss rate refers to the proportion of crude oil mass lost in gaseous form during production. The carbon dioxide conversion factor is used to convert crude oil loss into carbon dioxide emissions. CFA characterizes the ability of the capture system to separate carbon dioxide from the mixed gas. Storage efficiency characterizes the proportion of captured carbon dioxide successfully injected into the formation and permanently stored. The daily power consumption of the reinjection system is obtained by multiplying the amount of carbon dioxide recovered and reinjected by the power consumption coefficient of the reinjection system.

[0187] The daily carbon emissions and energy consumption of the reinjection system can be determined based on the daily electricity consumption. The daily carbon emissions of the reinjection system equal the daily electricity consumption multiplied by the grid carbon emission factor, reflecting the indirect carbon emissions generated by the electricity consumed in the reinjection process. The daily energy consumption of the reinjection system is obtained directly through unit conversion, equal to the daily electricity consumption multiplied by 3600, representing the total amount of electrical energy actually consumed by the reinjection system.

[0188] Direct fugitive carbon emissions can be determined by the difference between total fugitive carbon emissions and the amount of carbon recovered and reinjected. Total fugitive carbon emissions are the total amount of carbon dioxide generated during the production process, a portion of which is captured and reinjected, while the remainder is directly emitted into the atmosphere. Direct fugitive carbon emissions equal total fugitive carbon emissions minus the amount of carbon dioxide recovered and reinjected, reflecting the fugitive carbon emissions that were not captured.

[0189] Based on the daily carbon emissions of the reinjection system and the direct fugitive carbon emissions, the carbon emissions and energy consumption of the fugitive reinjection process can be determined. The total daily carbon emissions of the fugitive reinjection process are equal to the sum of the daily carbon emissions of the reinjection system (indirect emissions) and the direct fugitive carbon emissions (direct emissions). The total daily energy consumption of the fugitive reinjection process is equal to the daily energy consumption of the reinjection system, because the direct fugitive portion does not involve energy consumption.

[0190] The carbon emissions from the fugitive emission recovery process are decomposed into direct fugitive emissions and indirect recovery using a third energy consumption conversion model, establishing a carbon balance relationship among capture, recovery, and fugitive emissions. Compared to traditional methods that only calculate fugitive emissions or only calculate recovery energy consumption, this model can comprehensively evaluate the net emission reduction benefits of carbon capture and storage (CFS) technologies. The introduction of carbon capture efficiency and storage efficiency allows the model to reflect the impact of actual process levels on emission reduction effects; the introduction of the grid carbon emission factor allows the evaluation of indirect carbon emissions in the recovery process to reflect differences in regional power structure.

[0191] In some embodiments, the daily power consumption of the reinjection system is determined based on the third energy consumption conversion model; the daily carbon emissions and daily energy consumption of the reinjection system are determined based on the daily power consumption; the direct carbon emissions are determined based on the difference between the total fugitive carbon emissions and the recovered reinjected carbon emissions; and the carbon emissions and energy consumption of the fugitive reinjection process are determined based on the daily carbon emissions, daily energy consumption, and direct fugitive carbon emissions of the reinjection system. Specifically, this may further include: The following formula is used to calculate the total daily carbon emissions from escaping emissions: In the formula, The quantity is the daily liquid production mass, kg / d; 1 is the average crude oil loss rate, %; 28 is the CO2 conversion factor.

[0192] The above formula multiplies the daily liquid production mass by the average crude oil loss rate to obtain the crude oil loss mass, and then multiplies it by the conversion factor to obtain the total amount of carbon dioxide directly emitted during the production process.

[0193] The daily CO2 volume recovered and reinjected is calculated using the following formula: In the formula, Carbon emissions from the total daily escaping portion, in tons per day (t / d). For carbon capture efficiency, % For storage efficiency, %.

[0194] The above formula multiplies the total fugitive carbon emissions by the product of the capture efficiency and the storage efficiency to obtain the actual mass of carbon dioxide recovered and reinjected.

[0195] The daily carbon emissions from direct escaping are calculated using the following formula: In the formula, The daily CO2 volume recovered and reinjected, t / d; The total carbon emissions emitted daily, in tons per day (t / d).

[0196] The above formula is based on the principle of carbon balance. The total amount of carbon dioxide emitted into the atmosphere is obtained by subtracting the portion that is captured and reinjected from the total emitted carbon dioxide.

[0197] Calculate the daily power consumption of the reinjection system using the following formula: In the formula, The daily CO2 volume recovered and reinjected, t / d; The power consumption coefficient of the reinjection system is given in kWh / t.

[0198] The above formula multiplies the amount of carbon dioxide recovered and reinjected by the power consumption coefficient to obtain the daily power consumption of the reinjection system.

[0199] The daily carbon emissions of the reinjection system are calculated using the following formula: In the formula, The daily power consumption of the reinjection system is kWh / d; The carbon emission factor for the power grid is kg CO2e / kWh.

[0200] The above formula multiplies the power consumption of the reinjection system by the grid carbon emission factor to obtain the indirect carbon emissions generated by the power consumption of the reinjection process.

[0201] The daily energy consumption of the reinjection portion is calculated using the following formula: In the formula, The daily power consumption of the reinjection system is expressed in kWh / d; 3600 is the unit conversion factor.

[0202] The following formula is used to calculate the total daily carbon emissions of the fugitive reinjection portion: In the formula, The daily carbon emissions of the reinjection system are expressed in tons per day (t / d). The amount of carbon emissions that are directly emitted is t / d.

[0203] A complete carbon balance evaluation system for the fugitive emission reinjection process was established using the seven sets of formulas described above. Total fugitive carbon emissions were calculated based on crude oil loss rate and carbon dioxide conversion factor, quantifying fugitive emissions during production into calculable carbon emissions. The introduction of carbon capture efficiency and storage efficiency enabled the model to reflect the impact of actual process levels on emission reduction effects, providing a quantitative basis for optimizing capture processes. The introduction of the reinjection system's power consumption coefficient and the grid carbon emission factor allowed the indirect carbon emission evaluation of the reinjection process to reflect differences in equipment energy consumption levels and regional power structure. Direct fugitive carbon emissions were determined by the difference between total fugitive emissions and the recovered reinjection volume, demonstrating the complete application of the carbon balance principle. Finally, the indirect and direct carbon emissions were superimposed to obtain the net carbon emissions of the fugitive emission reinjection process.

[0204] As can be seen from the technical solutions provided in the embodiments of this specification above, the embodiments of this specification can determine the carbon emissions and energy consumption of each injection development stage based on the energy balance model and the series thermal resistance model; the energy balance model is used to characterize the energy conservation relationship of boiler steam production; the series thermal resistance model is used to characterize the multi-layer thermal resistance series relationship of pipelines or wells; the carbon emissions and energy consumption of each production development stage are determined based on the lifting power model, the heat loss compensation model, and the energy consumption conversion model; the lifting power model is used to characterize the conversion relationship between lifting power consumption and hydraulic work; the heat loss compensation model is used to characterize the conversion relationship between wellbore heat loss and heat tracing energy consumption; the energy consumption conversion model is used to characterize the conversion relationship between fuel consumption or electricity consumption and carbon emissions. By using energy balance and series thermal resistance models, a systematic and refined evaluation of carbon emissions and energy consumption at each stage of injection is achieved. By using lifting power model, heat loss compensation model and energy consumption conversion model, the sub-items of each stage at production are quantified. A carbon emission and energy consumption evaluation system covering the entire process is constructed, providing a quantitative basis for the low-carbon optimization and clean energy substitution benefit assessment of heavy oil thermal recovery.

[0205] The following is a specific embodiment of this specification: Taking the combined thermal recovery of heavy oil reservoirs using single steam and green electricity-green steam-CO2 as an example, referring to Figure 2 , Figure 3 , Figure 4 , Figure 5 , Figure 6 , Figure 7 , Figure 8 , Figure 9 , Figure 10 , Figure 11 and Figure 12 The study aims to evaluate the carbon emissions and energy consumption levels of conventional heavy oil thermal recovery development, while also assessing the carbon reduction potential of multi-energy synergistic thermal recovery models.

[0206] (1) Calculate the carbon emissions and energy consumption per ton of steam at the injection end well bottom: ① Carbon emissions and energy consumption per ton of steam at the boiler steam generation end: Assuming the lower heating value of coal is 25 × 10⁻⁶ 3 kJ / kg; target steam temperature is 264℃; steam boiler efficiency is 85%; carbon content of bituminous coal is 80%; carbon oxidation rate is 99%.

[0207] The amount of steam that can be produced from 1 ton of coal is: ; The carbon emissions produced by burning 1 ton of coal are: ; The energy consumption of burning 1 ton of coal is: ; Carbon emissions per ton of steam produced at the steam generator outlet: ; Energy consumption per ton of steam produced at the steam generator outlet: .

[0208] ② Calculate the carbon emissions and energy consumption per ton of steam at the wellhead: Assuming the injection temperature T s =264℃, , , , r in =0.045m, r ou =0.051m, r ins =0.127m, T a =25℃.

[0209] The convective heat transfer thermal resistance of the liquid film layer is: ; Thermoconductive resistance of the tube wall: ; Thermal resistance of insulation layer: ; Thermal resistance of the insulation layer to forced convection heat transfer with the atmosphere: ; Therefore, the total thermal resistance is: ; Heat conduction per unit time and length of pipeline: ; Assumption =5km, with a steam injection time of 1 hour, then the heat loss of the pipeline is: ; Boiler outlet steam heat capacity: ; The remaining steam at the wellhead is: ; The cumulative carbon emissions at the wellhead are: ; The cumulative energy consumption at the wellhead is: ; The carbon emissions per ton of steam obtained at the wellhead are: ; The energy consumption per ton of steam obtained at the wellhead is: .

[0210] ② Calculate the carbon emissions and energy consumption per ton of steam at the bottom of the well: Assuming injection temperature T s =264℃, , T W (1s) = 45℃, T W (3600s) = 50℃ , , , , r1=0.102m, r2=0.116m, r3=0.167m, r4=0.181m, r ci =0.201m, r co =0.227m, r w =0.277m, , .

[0211] The thermal resistance of the steam injection pipe wall is: ; Thermal resistance of insulation layer: ; Inner tube wall thermal resistance: ; Annular convective heat transfer thermal resistance (including convection and radiation): ; Thermal resistance of the outer tube wall: ; Thermal resistance of cement ring: ; Therefore, the total thermal resistance is: ; Dimensionless formation thermal conductivity time coefficient at initial time (1s): ; Dimensionless formation thermal conductivity time coefficient at the end of steam injection (taken as 1 hour, i.e., 3600 seconds): ; Thermal resistance of the formation at the initial moment (1s): ; Heat loss rate of the wellbore section at the initial moment (1s): ; Thermal resistance of the formation at the end time (3600s): ; Heat loss rate of the wellbore section at the end time (3600s): ; Logarithmic mean heat loss rate: ; Assuming H = 1 km, the heat loss of the wellbore is: ; Residual steam heat at the wellhead: ; The remaining steam at the bottom of the well is: ; The cumulative carbon emissions at the bottom of the well are: ; The cumulative energy consumption at the bottom of the well is: ; The carbon emissions per ton of steam consumed at the bottom of the well are: ; The energy consumption per ton of steam at the bottom of the well is: ; Since the green electricity and green steam generated by the multi-energy coupling system do not produce carbon emissions and energy consumption, the carbon emissions and energy consumption at the boiler steam production end are negligible. Only the pipeline transportation and well injection parts are considered (calculated in conjunction with carbon emission factors). Similarly, the carbon emissions and energy consumption per ton of steam consumed at the bottom of the well for the electricity-steam-CO2 co-extraction are calculated to be 0.071 and 0.434, respectively.

[0212] (2) Establish a single steam and electric-steam-CO2 co-generation thermal recovery simulation model at the mine scale. The grid system is 6×25×11 and the grid size is 50m×10m×1m. Set the steam injection cycle to 6 cycles and the drive pressure to 5MPa. Perform numerical simulation calculations and derive the steam injection rate, oil production rate and liquid production rate, as shown in Table 1.

[0213] Table 1

[0214] (3) The daily liquid production (360m³) calculated using simulation. 3 For example, assuming the density of the produced fluid is 980 kg / m³ 3The screw pump's transmission system has a total efficiency of 70%, a pump efficiency of 80%, a grid carbon emission factor of 0.5777 kg CO2e / kWh, a wellhead target temperature of 60℃, a pipeline length of 5000m, a liquid specific heat capacity of 4 kJ / kg·℃, an oil-water separation target temperature of 80℃, an average crude oil loss rate of 0.0615%, a carbon capture efficiency of 80%, a carbon sequestration efficiency of 20%, and a reinjection system power consumption coefficient of 150kWh / t. Calculate the carbon emissions and energy consumption at the production end corresponding to this time step: ①Calculate the carbon emissions and energy consumption of the fluid lift section in the wellbore: Quality of the lift product fluid: ; Theoretical hydraulic work done in lifting the product fluid: ; Power consumption calculation: ; Carbon emissions from wellbore lifting: ; Wellbore lifting energy consumption: .

[0215] ② Calculate the carbon emissions and energy consumption of the wellbore heating system: Production-weighted average temperature method for calculating bottom hole temperature: According to the exported data, 360m 3 The production cycle corresponding to the / d time step is the 5th day of the first round of steam injection. Since steam injection lasts for 15 days and well shut-in for 3 days, if we take one day as the calculation cycle, the initial time is 1900800s (day 22) and the ending time is 1987200s (day 23), so the production time is 86400 seconds (1 day). To ensure calculation accuracy and reduce the amount of calculation, the wellbore temperature and formation temperature in this round are replaced by the weighted logarithmic average temperature. The bottom hole temperature corresponding to the high production value in this round is 230.5℃, the bottom hole temperature corresponding to the median daily production value is 152.8℃, and the bottom hole temperature corresponding to the low daily production value is 74.78℃.

[0216] ; Wellbore weighted logarithmic mean temperature: ; If the average formation temperature during one steam injection cycle is 50.76℃, then the heat conduction per unit length of wellbore is: Daily liquid production: 360m³ 3 The dimensionless formation thermal conductivity time coefficient corresponding to the time step / d (i.e., 1987200s): ; The thermal resistance of the formation at that moment: ; The heat loss rate of the wellbore section at that moment: ; The dimensionless formation thermal conductivity time coefficient corresponding to the time step of the previous day (i.e., 1900800s):

[0217] The thermal resistance of the formation at that moment:

[0218] The heat loss rate of the wellbore section at that moment:

[0219] Logarithmic mean heat loss rate: ; Wellbore heat loss: ; Carbon emissions from wellbore heating: ; Wellbore heating energy consumption: .

[0220] ③Calculate the carbon emissions and energy consumption of the fluid gathering and transportation section: Heat conduction per unit length of transport pipeline: ; Heat loss of transport pipeline: ; Carbon emissions from transport pipelines: ; Energy consumption of transportation pipelines: .

[0221] ④ Calculate the carbon emissions and energy consumption of the ground treatment section: Heat required for oil-water separation: ; Fuel (coal) consumption: ; Ground-based carbon emission treatment: ; Ground processing energy consumption: .

[0222] ⑤ Calculate the carbon emissions and energy consumption of the fugitive reinjection portion: Total carbon emissions from the volatile component: ; Daily CO2 volume recovered and reinjected: ; Direct carbon emissions: ; Power consumption of the reinjection system: ; Carbon emissions from the reinjection system: ; Energy consumption of reinjection portion: ; Total carbon emissions from the fugitive reinjection portion: .

[0223] Based on the above-mentioned method for determining carbon emissions and energy consumption throughout the entire heavy oil thermal recovery and development process, this specification also proposes embodiments of a device for determining carbon emissions and energy consumption throughout the entire heavy oil thermal recovery and development process. For example... Figure 13 As shown, the carbon emission and energy consumption determination device 1300 for the entire heavy oil thermal recovery development process may specifically include the following modules: The first determining module 1301 is used to determine the carbon emissions and energy consumption of each injection development stage based on the energy balance model and the series thermal resistance model; the energy balance model is used to characterize the energy conservation relationship of boiler steam production; the series thermal resistance model is used to characterize the multi-layer thermal resistance series relationship of pipelines or wells. The second determining module 1302 is used to determine the carbon emissions and energy consumption of each production and development stage based on the lifting power model, the heat loss compensation model, and the energy consumption conversion model. The lifting power model is used to characterize the conversion relationship between lifting power consumption and hydraulic work. The heat loss compensation model is used to characterize the conversion relationship between wellbore heat loss and heat tracing energy consumption. The energy consumption conversion model is used to characterize the conversion relationship between fuel consumption or electricity consumption and carbon emissions.

[0224] As can be seen from the technical solutions provided in the embodiments of this specification above, the embodiments of this specification can determine the carbon emissions and energy consumption of each injection development stage based on the energy balance model and the series thermal resistance model; the energy balance model is used to characterize the energy conservation relationship of boiler steam production; the series thermal resistance model is used to characterize the multi-layer thermal resistance series relationship of pipelines or wells; the carbon emissions and energy consumption of each production development stage are determined based on the lifting power model, the heat loss compensation model, and the energy consumption conversion model; the lifting power model is used to characterize the conversion relationship between lifting power consumption and hydraulic work; the heat loss compensation model is used to characterize the conversion relationship between wellbore heat loss and heat tracing energy consumption; the energy consumption conversion model is used to characterize the conversion relationship between fuel consumption or electricity consumption and carbon emissions. By using energy balance and series thermal resistance models, a systematic and refined evaluation of carbon emissions and energy consumption at each stage of injection is achieved. By using lifting power model, heat loss compensation model and energy consumption conversion model, the sub-items of each stage at production are quantified. A carbon emission and energy consumption evaluation system covering the entire process is constructed, providing a quantitative basis for the low-carbon optimization and clean energy substitution benefit assessment of heavy oil thermal recovery.

[0225] This specification also provides a computer device for determining carbon emissions and energy consumption throughout the entire heavy oil thermal recovery development process, including a processor and a memory for storing processor-executable instructions. Specifically, the processor can perform the following tasks according to the instructions: determining carbon emissions and energy consumption for each injection development stage based on an energy balance model and a series thermal resistance model; the energy balance model characterizes the energy conservation relationship for boiler steam production; the series thermal resistance model characterizes the multi-layer thermal resistance series relationship of pipelines or wellbores; determining carbon emissions and energy consumption for each production development stage based on a lift power model, a heat loss compensation model, and an energy consumption conversion model; the lift power model characterizes the conversion relationship between lift power consumption and hydraulic work; the heat loss compensation model characterizes the conversion relationship between wellbore heat loss and heat tracing energy consumption; and the energy consumption conversion model characterizes the conversion relationship between fuel consumption or electricity consumption and carbon emissions.

[0226] To execute the above instructions more accurately, please refer to... Figure 14 As shown in the embodiments of this specification, another specific computer device 1400 is also provided, wherein the computer device 1400 includes a network communication port 1401, a processor 1402 and a memory 1403, and the above structures are connected by internal cables so that the various structures can perform specific data interaction.

[0227] The processor 1402 can specifically be used to: determine the carbon emissions and energy consumption of each injection development stage based on an energy balance model and a series thermal resistance model; the energy balance model is used to characterize the energy conservation relationship of boiler steam production; the series thermal resistance model is used to characterize the multi-layer thermal resistance series relationship of pipelines or wells; and determine the carbon emissions and energy consumption of each production development stage based on a lifting power model, a heat loss compensation model, and an energy consumption conversion model; the lifting power model is used to characterize the conversion relationship between lifting power consumption and hydraulic work; the heat loss compensation model is used to characterize the conversion relationship between wellbore heat loss and heat tracing energy consumption; and the energy consumption conversion model is used to characterize the conversion relationship between fuel consumption or electricity consumption and carbon emissions.

[0228] The memory 1403 can be used to store the corresponding instruction program.

[0229] In this embodiment, the network communication port 1401 can be a virtual port bound to different communication protocols, thereby enabling the sending or receiving of different data. For example, the network communication port can be a port responsible for web data communication, a port responsible for FTP data communication, or a port responsible for email data communication. Furthermore, the network communication port can also be a physical communication interface or communication chip. For example, it can be a wireless mobile network communication chip, such as GSM or CDMA; it can also be a Wi-Fi chip; or it can be a Bluetooth chip.

[0230] In this embodiment, the processor 1402 can be implemented in any suitable manner. For example, the processor can take the form of a microprocessor or processor and a computer-readable medium storing computer-readable program code (e.g., software or firmware) executable by the (micro)processor, logic gates, switches, application-specific integrated circuits (ASICs), programmable logic controllers, and embedded microcontrollers, etc. This specification is not limiting.

[0231] In this embodiment, the memory 1403 includes volatile memory and non-volatile memory. The memory 1403 can include multiple layers. In digital systems, anything that can store binary data can be a memory; in integrated circuits, a circuit with storage function but no physical form is also called a memory, such as RAM, FIFO, etc.; in a system, a storage device with a physical form is also called a memory, such as a memory stick, TF card, etc.

[0232] Furthermore, embodiments of this specification also provide a computer-readable storage medium storing a computer program that, when executed by a processor, implements the above-described... Figure 1The instructions outline the method for determining carbon emissions and energy consumption throughout the entire process of heavy oil thermal recovery and development.

[0233] Furthermore, embodiments of this specification provide a computer program product comprising a computer program that, when executed by a processor, implements the above-described... Figure 1 The method for determining carbon emissions and energy consumption throughout the entire process of heavy oil thermal recovery and development is shown.

[0234] It should be understood that in the various embodiments of this specification, the sequence number of each process does not imply the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of this specification.

[0235] It should also be understood that, in the embodiments of this specification, the term "and / or" is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, and B existing alone. Additionally, the character " / " in this specification generally indicates that the preceding and following related objects have an "or" relationship.

[0236] Those skilled in the art will understand that embodiments of the present invention can be provided as methods, systems, or computer program products. Therefore, the present invention can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, the present invention can take the form of a computer program product embodied on one or more computer-usable storage media (including, but not limited to, disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0237] This invention is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of the invention. It will be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, generate instructions for implementing the flowchart illustrations and / or block diagrams. Figure 1 One or more processes and / or boxes Figure 1 A device that provides the functions specified in one or more boxes.

[0238] These computer program instructions may also be stored in a computer-readable storage medium that can direct a computer or other programmable data processing device to function in a particular manner, such that the instructions stored in the computer-readable storage medium produce an article of manufacture including instruction means, which are implemented in a process Figure 1One or more processes and / or boxes Figure 1 The function specified in one or more boxes.

[0239] These computer program instructions may also be loaded onto a computer or other programmable data processing equipment to cause a series of operational tasks to be performed on the computer or other programmable equipment to produce a computer-implemented process, thereby providing instructions that execute on the computer or other programmable equipment for implementing the process. Figure 1 One or more processes and / or boxes Figure 1 The task is a function specified in one or more boxes.

[0240] The specific embodiments described above further illustrate the purpose, technical solution, and beneficial effects of the present invention. It should be understood that the above descriptions are merely specific embodiments of the present invention and are not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A method for determining carbon emissions and energy consumption throughout the entire process of heavy oil thermal recovery and development, characterized in that, The entire process of heavy oil thermal recovery development includes multiple injection development stages and multiple production development stages. The method includes: Based on the energy balance model and the series thermal resistance model, the carbon emissions and energy consumption of each injection development stage are determined; the energy balance model is used to characterize the energy conservation relationship of boiler steam production; the series thermal resistance model is used to characterize the multi-layer thermal resistance series relationship of pipelines or wells. Based on the lifting power model, heat loss compensation model, and energy consumption conversion model, the carbon emissions and energy consumption of each production and development stage are determined. The lifting power model is used to characterize the conversion relationship between lifting power consumption and hydraulic work. The heat loss compensation model is used to characterize the conversion relationship between wellbore heat loss and heat tracing energy consumption. The energy consumption conversion model is used to characterize the conversion relationship between fuel consumption or electricity consumption and carbon emissions.

2. The method according to claim 1, characterized in that, The injection development stage includes the boiler steam generation stage; the energy balance model is used to characterize the energy conservation relationship between the lower heating value of fuel, boiler efficiency, steam enthalpy and feedwater enthalpy in the boiler steam generation stage. The carbon emissions and energy consumption of each injection development stage are determined based on the energy balance model and the series thermal resistance model, including: Based on the energy balance model, the steam production per unit of fuel is determined; The carbon emissions and energy consumption of the boiler steam production process are determined based on steam output, fuel consumption, fuel carbon content, carbon oxidation rate, and lower heating value of the fuel.

3. The method according to claim 1, characterized in that, The injection development process also includes the steam injection pipeline process; the series thermal resistance model includes a first series thermal resistance model; the first series thermal resistance model is used to characterize the series relationship between the liquid film layer convective heat transfer thermal resistance, the pipe wall thermal conductivity thermal resistance, the insulation layer thermal conductivity thermal resistance, and the forced convection heat transfer thermal resistance between the insulation layer and the atmosphere. The determination of carbon emissions and energy consumption for each injection and development stage based on the energy balance model and series thermal resistance model also includes: Based on the first series thermal resistance model, the total thermal resistance of the steam injection pipeline is determined; The heat loss of the pipeline is determined based on the steam temperature, ambient temperature, total thermal resistance of the steam injection pipeline, and length of the steam injection pipeline. Based on the heat loss of the pipeline and the enthalpy of the steam, determine the carbon emissions and energy consumption generated by the boiler steam production heat loss in the steam injection pipeline.

4. The method according to claim 1, characterized in that, The injection development stage includes the steam injection wellbore stage; the series thermal resistance model includes a second series thermal resistance model; the second series thermal resistance model is used to characterize the series relationship between the thermal resistance of the steam injection pipe wall, the thermal resistance of the insulation layer, the annular convection heat transfer thermal resistance, the annular radiation heat transfer thermal resistance, the casing wall thermal resistance, the cement sheath thermal resistance, and the formation thermal resistance. The determination of carbon emissions and energy consumption for each injection and development stage based on the energy balance model and series thermal resistance model also includes: Based on the second series thermal resistance model, the total thermal resistance of the wellbore is determined; The heat loss of the wellbore is determined based on the steam injection temperature, formation temperature, total thermal resistance of the wellbore, formation thermal resistance, and well depth. Based on the heat loss of the well shaft and the enthalpy of the steam, determine the carbon emissions and energy consumption generated by the boiler steam production heat loss in the steam injection well shaft stage.

5. The method according to claim 1, characterized in that, The production development stage includes the production well lifting stage; the lifting power model is used to characterize the conversion relationship between power consumption and hydraulic work, transmission system efficiency and pump efficiency during the process of lifting the produced fluid from the bottom of the well to the wellhead. The carbon emissions and energy consumption of each extraction and development stage are determined based on the lifting power model, heat loss compensation model, and energy consumption conversion model, including: Based on the aforementioned lifting power model, the daily power consumption is determined; Based on the daily power consumption and the power grid carbon emission factor, the carbon emissions and energy consumption of the production well lifting process are determined.

6. The method according to claim 1, characterized in that, The production and development process also includes wellbore heating; the heat loss compensation model is used to characterize the temperature difference relationship between the average wellbore temperature and the formation temperature. The determination of carbon emissions and energy consumption for each extraction and development stage based on the lifting power model, heat loss compensation model, and energy consumption conversion model also includes: Based on the aforementioned heat loss compensation model, the daily heat loss of the wellbore is determined; Based on the daily heat loss of the well shaft, boiler efficiency, and fuel carbon emission factor, the carbon emissions and energy consumption of the well shaft heat tracing process are determined.

7. The method according to claim 1, characterized in that, The production and development stage also includes a fluid gathering and transportation stage; the energy consumption conversion model includes a first energy consumption conversion model; the first energy consumption conversion model is used to characterize the conversion relationship between the heating energy required to maintain the flow of produced fluid in the surface pipeline and the fuel consumption; The determination of carbon emissions and energy consumption for each extraction and development stage based on the lifting power model, heat loss compensation model, and energy consumption conversion model also includes: Based on the first energy consumption conversion model, the daily heat loss of the transportation pipeline is determined; Based on the daily heat loss, boiler efficiency, and fuel carbon emission factor, the carbon emissions and energy consumption of the fluid gathering and transportation process are determined.

8. The method according to claim 1, characterized in that, The extraction and development stage also includes a surface processing stage; the energy consumption conversion model includes a second energy consumption conversion model; the second energy consumption conversion model is used to characterize the conversion relationship between the heat required for oil-water separation and crude oil dehydration processes and fuel consumption; The determination of carbon emissions and energy consumption for each extraction and development stage based on the lifting power model, heat loss compensation model, and energy consumption conversion model also includes: Based on the second energy consumption conversion model, the daily fuel consumption required for oil-water separation is determined; Based on the daily fuel consumption, fuel carbon content, carbon oxidation rate, boiler efficiency, and fuel calorific value, the carbon emissions and energy consumption of the ground treatment process are determined.

9. The method according to claim 1, characterized in that, The extraction and development phase also includes an efflux reinjection phase; the energy consumption conversion model includes a third energy consumption conversion model; the third energy consumption conversion model is used to characterize the conversion relationship between the electricity consumption and carbon emissions required for the carbon dioxide capture, compression and injection underground storage system; The determination of carbon emissions and energy consumption for each extraction and development stage based on the lifting power model, heat loss compensation model, and energy consumption conversion model also includes: Based on the aforementioned third energy consumption conversion model, the daily power consumption of the reinjection system is determined; Based on the daily power consumption, determine the daily carbon emissions and daily energy consumption of the reinjection system; The direct carbon emissions are determined based on the difference between the total fugitive carbon emissions and the recovered and reinjected carbon emissions. Based on the daily carbon emissions, daily energy consumption, and direct escaping carbon emissions of the reinjection system, the carbon emissions and energy consumption of the escaping reinjection process are determined.

10. A device for determining carbon emissions and energy consumption throughout the entire process of heavy oil thermal recovery and development, characterized in that, The entire process of heavy oil thermal recovery development includes multiple injection development stages and multiple production development stages. The device includes: The first determining module is used to determine the carbon emissions and energy consumption of each injection development stage based on the energy balance model and the series thermal resistance model; the energy balance model is used to characterize the energy conservation relationship of boiler steam production; the series thermal resistance model is used to characterize the multi-layer thermal resistance series relationship of pipelines or wells. The second determining module is used to determine the carbon emissions and energy consumption of each production and development stage based on the lifting power model, the heat loss compensation model, and the energy consumption conversion model. The lifting power model is used to characterize the conversion relationship between lifting power consumption and hydraulic work. The heat loss compensation model is used to characterize the conversion relationship between wellbore heat loss and heat tracing energy consumption. The energy consumption conversion model is used to characterize the conversion relationship between fuel consumption or electricity consumption and carbon emissions.

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