A heavy oil reservoir exploitation method, device, electronic equipment and storage medium

Abstract

The application discloses a heavy oil reservoir exploitation method and device, electronic equipment and storage medium. The method comprises the following steps: controlling an injection machine to inject oil displacement medium into an injection well of a target heavy oil reservoir, and controlling the injection machine to inject viscosity-reducing substances into a production well of the target heavy oil reservoir; during the process of well soaking and well opening production of the production well, the injection machine is controlled to inject the viscosity-reducing substances into the middle section of the production well in a slug manner until the production well of the target heavy oil reservoir completes a preset number of single-round huff and puff; the injection machine is controlled to inject the oil displacement medium into the injection well until the water cut of the production well of the target heavy oil reservoir reaches a first threshold value, the injection machine is controlled to inject water into the injection well alone until the water cut of the production well of the target heavy oil reservoir reaches a second threshold value, and the exploitation of the target heavy oil reservoir is completed. The technical scheme of the application realizes the increase of the yield and recovery rate of the target heavy oil reservoir by the cooperative operation of the injection well and the production well of the target heavy oil reservoir.

Description

Technical Field

[0001] This invention relates to the field of oilfield development technology, and in particular to a method, apparatus, electronic equipment and storage medium for heavy oil reservoir extraction. Background Technology

[0002] Deep heavy oil reservoirs refer to heavy oil reservoirs with a burial depth greater than 1000m, a crude oil viscosity greater than 100cP containing gas underground, and a permeability less than 300mD. These reservoirs are extremely difficult to develop. my country has over 800 million tons of deep heavy oil resources, and there is a demand for stable heavy oil production. In the next ten years, PetroChina's cold-extraction production of heavy oil is expected to reach over 2 million tons. The economical and effective development of these reservoirs is of great significance for stabilizing heavy oil production.

[0003] Currently, the main development method for deep heavy oil reservoirs is conventional waterflooding. During conventional waterflooding, the deep burial depth, high crude oil viscosity, low permeability, strong heterogeneity, and unsuitable operating conditions create dominant water flow channels within the reservoir, resulting in low flow resistance. This easily leads to ineffective water injection, significantly reducing oil recovery and economic benefits; the predicted waterflooding recovery rate is only 13%.

[0004] To address the issues of dominant channels and ineffective water injection during waterflooding, conventional techniques include foam flooding and polymer flooding. By injecting foam or polymer solutions into the injection well, the water absorption profile of the well can be improved, thereby increasing the waterflood swept volume and enhancing the recovery rate.

[0005] However, most polymers currently used in polymer flooding (PAM-based) are relatively expensive, requiring large quantities due to their degradation and retention in the reservoir. The effectiveness of polymer flooding is also significantly affected by shear rate and salinity. The processes for polymer retention in the reservoir, production fluid treatment, and separation are complex, challenging, and costly. Furthermore, in foam flooding with gas injection and huff-and-puff, the gas's effective range within the reservoir is limited (10-15m) due to the inherent mechanisms of huff-and-puff development, resulting in limited enhanced oil recovery (not exceeding 10%). Summary of the Invention

[0006] This invention provides a method, apparatus, electronic equipment, and storage medium for heavy oil reservoir development, in order to increase the production and recovery rate of the target heavy oil reservoir.

[0007] In a first aspect, embodiments of the present invention provide a method for exploiting heavy oil reservoirs, the method comprising:

[0008] The injection machine is controlled to inject an oil displacement medium into the injection well of the target heavy oil reservoir, and to inject a viscosity-reducing substance into the production well of the target heavy oil reservoir. The oil displacement medium includes glycerol-water solution and carbon dioxide, and the viscosity-reducing substance includes oil-soluble viscosity reducer, nitrogen and carbon dioxide. The injection well and production well of the target heavy oil reservoir are connected by a bottom channel so that the production oil from the injection well flows to the production well.

[0009] During the well-steaming and well-opening production processes of the production well in the target heavy oil reservoir, the injection machine is controlled to inject the viscosity-reducing substance into the slug of the production well in the target heavy oil reservoir until the production well in the target heavy oil reservoir completes a preset number of single-round inrush and outrushes.

[0010] The injection machine is controlled to inject the oil displacement medium into the injection well of the target heavy oil reservoir until the water cut of the production well of the target heavy oil reservoir reaches a first threshold. The injection machine is then controlled to inject water separately into the injection well of the target heavy oil reservoir until the water cut of the production well of the target heavy oil reservoir reaches a second threshold. The exploitation of the target heavy oil reservoir ends when the first threshold is less than the second threshold.

[0011] Secondly, embodiments of the present invention also provide a heavy oil reservoir exploitation apparatus, the apparatus comprising:

[0012] The injection module for injection wells is used to control the injection machine to inject oil-displacing media into the injection well of the target heavy oil reservoir and to control the injection machine to inject viscosity-reducing substances into the production well of the target heavy oil reservoir. The oil-displacing media includes glycerol-water solution and carbon dioxide, and the viscosity-reducing substances include oil-soluble viscosity reducers, nitrogen and carbon dioxide. The injection well and production well of the target heavy oil reservoir are connected by a bottom channel so that the production oil from the injection well flows to the production well.

[0013] The production well constraint module is used to control the injection machine to inject viscosity-reducing substances into the slug of the production well in the target heavy oil reservoir during the well shut-in and well opening processes, until the production well in the target heavy oil reservoir completes a preset number of single-round inrush and out.

[0014] The injection well constraint module controls the injection machine to inject the oil displacement medium into the injection well of the target heavy oil reservoir until the water cut of the production well of the target heavy oil reservoir reaches a first threshold. The module then controls the injection machine to inject water separately into the injection well of the target heavy oil reservoir until the water cut of the production well of the target heavy oil reservoir reaches a second threshold. The exploitation of the target heavy oil reservoir ends when the first threshold is less than the second threshold.

[0015] Thirdly, embodiments of the present invention also provide an electronic device, including a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the program to implement the heavy oil reservoir exploitation method as described in any of the embodiments of the present invention.

[0016] Fourthly, embodiments of the present invention also provide a storage medium for storing computer-executable instructions, which, when executed by a computer processor, are used to perform a heavy oil reservoir exploitation method as described in any of the embodiments of the present invention.

[0017] The technical solution of this invention achieves increased production and recovery rate of the target heavy oil reservoir by synergistically injecting glycerol-water solution and carbon dioxide into the injection well, and injecting oil-soluble viscosity reducer, nitrogen, and carbon dioxide into the production well. Furthermore, it involves implementing injection schemes for the production and injection wells of the target heavy oil reservoir according to different conditions.

[0018] It should be understood that the description in this section is not intended to identify key or essential features of the embodiments of the present invention, nor is it intended to limit the scope of the invention. Other features of the invention will become readily apparent from the following description. Attached Figure Description

[0019] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0020] Figure 1 This is a flowchart of a heavy oil reservoir exploitation method provided in Embodiment 1 of the present invention;

[0021] Figure 2 This is a graph showing the relationship between the viscosity of glycerol-water solution and the mass concentration of glycerol under different temperature conditions, provided in Embodiment 1 of the present invention.

[0022] Figure 3 This is a schematic diagram of the distribution of the injected medium in the oil layer during a single-round throughput process provided in Embodiment 1 of the present invention;

[0023] Figure 4 This is a schematic diagram of the distribution of the injected medium in the oil layer after completing a preset number of single-round throughput processes, as provided in Embodiment 1 of the present invention.

[0024] Figure 5 This is a schematic diagram of the distribution of the injected medium in the reservoir after the water cut of the production well reaches the first threshold, provided in Embodiment 1 of the present invention.

[0025] Figure 6 This is a comparison curve of the production of heavy oil reservoirs provided in Embodiment 1 of the present invention and conventional water flooding in the target heavy oil reservoir.

[0026] Figure 7This is a comparison curve of the production of heavy oil reservoir extraction method provided in Embodiment 1 of the present invention and the production of target heavy oil reservoir extraction using natural gas huff and puff;

[0027] Figure 8 This is a schematic diagram of a heavy oil reservoir extraction device provided in Embodiment 2 of the present invention;

[0028] Figure 9 This is a schematic diagram of the structure of an electronic device for implementing the heavy oil reservoir exploitation method of this invention. Detailed Implementation

[0029] To enable those skilled in the art to better understand the present invention, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of the present invention.

[0030] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this invention 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 of the invention 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, system, product, or apparatus that comprises 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 apparatus.

[0031] Example 1

[0032] Figure 1 The present invention provides a flowchart of a method for exploiting heavy oil reservoirs in Embodiment 1. This embodiment is applicable to heavy oil reservoir exploitation. The method can be executed by a heavy oil reservoir exploitation device, which can be implemented in hardware and / or software. The heavy oil reservoir exploitation device can be configured in any electronic device with network communication and computing capabilities.

[0033] like Figure 1 As shown, the method includes:

[0034] S110. Control the injection machine to inject oil displacement medium into the injection well of the target heavy oil reservoir, and control the injection machine to inject viscosity-reducing substance into the production well of the target heavy oil reservoir; wherein, the oil displacement medium includes glycerol-water solution and carbon dioxide, and the viscosity-reducing substance includes oil-soluble viscosity reducer, nitrogen and carbon dioxide, and the injection well and production well of the target heavy oil reservoir are connected by a bottom channel so that the production oil from the injection well flows to the production well.

[0035] In this embodiment of the application, the oil displacement medium refers to the substance used to drive heavy oil in the development of the target heavy oil reservoir, and the viscosity reducing substance refers to the substance used to reduce the viscosity and drive heavy oil in the development of the target heavy oil reservoir.

[0036] The oil displacement medium includes a glycerol-water solution and carbon dioxide. In this embodiment, the glycerol used can be a byproduct of biodiesel production. Glycerol is a viscous liquid, insoluble in oil, but miscible with water in various proportions. Adding a certain proportion of glycerol-water solution during the oil displacement process in the injection well of the target heavy oil reservoir can increase the viscosity of the oil displacement medium, improve sweep efficiency, and thus increase oil production and recovery rate. Furthermore, due to the high density of glycerol (1.261 g / cm³),... 3 During the oil displacement process involving the injection of glycerol-water solution, the oil-water interface of the produced liquid is relatively stable, making separation easier. Furthermore, separating glycerol from the produced liquid can reduce development costs.

[0037] Meanwhile, carbon dioxide is added during the oil displacement process in the injection well of the target heavy oil reservoir. When carbon dioxide dissolves in oil, it can reduce the viscosity of crude oil and improve the oil-water mobility ratio, thereby increasing the sweep efficiency of the oil displacement medium, achieving the best oil displacement effect, and improving the recovery rate.

[0038] The viscosity-reducing substances include an oil-soluble viscosity reducer, nitrogen, and carbon dioxide. In this embodiment, the oil-soluble viscosity reducer is a copolymeric viscosity reducer, which can be prepared by solution polymerization. It is formulated using octadecyl methacrylate (SMA), N-phenylmaleimide (N-PMI), and vinyl acetate (VA) as monomers in a monomer ratio of 10:8:3. The optimal reaction conditions are: reaction temperature 70°C, reaction time 6 hours, and initiator addition of 1 wt%. Under these conditions, the oil-soluble viscosity reducer, when added to heavy oil at a concentration of 0.3 wt%, exhibits the best viscosity-reducing effect, achieving a viscosity reduction rate of 55.49%.

[0039] In the process of oil displacement in production wells of target heavy oil reservoirs, nitrogen is added. Due to its low density and viscosity, nitrogen can generate a driving force in the reservoir, propelling the flow of heavy oil. At the same time, nitrogen can also occupy a certain space, maintaining reservoir pressure and improving production efficiency.

[0040] By injecting glycerol-water solution and carbon dioxide into the injection wells of the target heavy oil reservoir, and injecting oil-soluble viscosity reducers, nitrogen and carbon dioxide into the production wells of the target heavy oil reservoir, the two-end oil displacement operation of the injection wells and production wells is achieved, which accelerates the connection between injection and production wells and the overall oil displacement efficiency, and is conducive to improving the oil production rate and recovery rate of the entire production process.

[0041] As an optional but not limited implementation, controlling the injection machine to inject glycerol-water solution and carbon dioxide into the injection well of the target heavy oil reservoir includes:

[0042] The injection machine is controlled to alternately inject a reference concentration of glycerol-water solution and carbon dioxide into the slug of the injection well in the target heavy oil reservoir. The reference concentration represents the mass concentration of glycerol in water.

[0043] In this embodiment, the slug refers to the injection of glycerol-water solution and carbon dioxide in a segmented injection structure. After the oil displacement medium is injected into the oil layer in the injection well of the target heavy oil reservoir, a distinct glycerol-water solution oil displacement zone is formed, which is then replaced by another substance, carbon dioxide. By using a multi-slug alternating injection method, the oil displacement effect can be effectively improved.

[0044] A glycerol-water solution of the reference concentration can maximize oil displacement efficiency while ensuring effective displacement by the glycerol-water solution.

[0045] During the oil displacement process, the slug alternately injects glycerol-water solution and carbon dioxide. Injecting a reference concentration of glycerol-water solution increases the viscosity of the aqueous phase in the target heavy oil reservoir, improving the mobility control capability of waterflooding, reducing fingering, and allowing the glycerol-water solution to more uniformly spread throughout the reservoir, reaching areas that are otherwise difficult to reach. Injecting carbon dioxide continuously dissolves it in the heavy oil and water, forming a miscible zone in a portion of the heavy oil under certain pressure and temperature. This completely eliminates the interfacial tension between water and oil in localized or all heavy oil areas and reduces the viscosity of the heavy oil, thus improving the oil displacement effect.

[0046] As an optional but not limited implementation, the injection machine is controlled to alternately inject a reference concentration of glycerol-water solution and carbon dioxide into the slug of the injection well in the target heavy oil reservoir, including:

[0047] Determine the target viscosity of the glycerol-water solution;

[0048] The reference concentration of the injected glycerol-water solution is determined based on the target viscosity;

[0049] The injection machine is controlled to alternately inject the reference concentration of glycerol-water solution and carbon dioxide into the slug of the injection well in the target heavy oil reservoir.

[0050] In this embodiment, the target viscosity refers to the viscosity value of the glycerol-water solution used for viscosity reduction and displacement of heavy oil in the target heavy oil reservoir. Higher viscosity glycerol-water solutions help improve the flow control of the displacement fluid, reduce its surge, and increase oil displacement efficiency, but may increase injection pressure. Lower viscosity glycerol-water solutions may be less effective in terms of flow control and sweep efficiency, but require lower injection pressure. Therefore, it is necessary to select a glycerol-water solution with an appropriate target viscosity based on the target heavy oil reservoir conditions and oil displacement requirements to achieve the best oil displacement effect.

[0051] It should be noted that different viscosity values ​​of glycerol-water solutions correspond to different mass concentrations of glycerol in water. Based on the known relationship between the viscosity and mass concentration of glycerol-water solutions, the mass concentration of glycerol corresponding to the target viscosity of the glycerol-water solution is determined as the reference concentration. The injection machine is controlled to alternately inject the reference concentration of glycerol-water solution and carbon dioxide into the sluice of the injection well in the target heavy oil reservoir to improve the oil displacement effect.

[0052] See Figure 2 The graph shows the relationship between the viscosity of glycerol-water solution and the mass concentration of glycerol under different temperature conditions. The graph includes the relationship between the viscosity of glycerol-water solution and the mass concentration of glycerol at an injection temperature of 20℃ and at an injection temperature of 10℃.

[0053] Specifically, the steps for alternately injecting glycerol-water solution and CO2 into the slug of the injection well in the target heavy oil reservoir are as follows: First, determine the target viscosity of the glycerol-water solution to be injected at 20°C (20-40 cP). Then, inject a glycerol-water solution with a reference concentration range of 50%-80% (20°C) into the injection well of the target heavy oil reservoir. The mass ratio of injected CO2 to glycerol-water solution is 1:1-2:1, and the injection intensity of the glycerol-water solution is 1-2 m. 3 The CO2 injection intensity is 1-2 t / d / m, and the glycerol-water solution and CO2 slug are injected alternately every 1-3 months.

[0054] As an optional but not limited implementation, controlling the injection machine to inject viscosity-reducing substances into the production wells of the target heavy oil reservoir includes:

[0055] The injection machine is controlled to alternately inject viscosity-reducing substances into the slug of the production well in the target heavy oil reservoir in multiple single-round huff and puff processes; the single-round huff and puff process includes the viscosity-reducing substance injection process, the well shut-in process, and the well opening and production process.

[0056] In this embodiment of the application, the production well's throughput process means that the production well is simultaneously producing and recovering oil while also carrying out an oil displacement process, thereby accelerating the oil displacement efficiency and recovery rate.

[0057] The injection of viscosity-reducing substances into production wells can promptly reduce the viscosity of heavy oil near the production wells, overcoming the problem that oil cannot be extracted in a timely manner even after the injection wells have been flooded.

[0058] The well-steaming process allows the oil displacement agent to interact better with the heavy oil, promoting the flow and extraction of the heavy oil, which helps to further improve the oil recovery rate of the reservoir.

[0059] Well opening is the process of recovering produced fluids, which include oil, gas, water, and other substances.

[0060] The process of controlling the injection machine to inject viscosity-reducing substances into the production wells of the target heavy oil reservoir in multiple single-round injections and churns refers to the cyclical process of injecting viscosity-reducing substances, shutting down the well, and starting production in the production wells of the target heavy oil reservoir multiple times, so as to maximize the exploitation of the target heavy oil reservoir and improve the recovery rate.

[0061] As an optional but not limited implementation, the single-round throughput process includes:

[0062] The injection machine is controlled to inject an oil-soluble viscosity reducer into the production well of the target heavy oil reservoir. Carbon dioxide and nitrogen are alternately injected into the production well of the target heavy oil reservoir. Finally, nitrogen is injected into the production well of the target heavy oil reservoir, and the viscosity reducer injection process of the production well of the target heavy oil reservoir is completed.

[0063] The well valves are closed according to the well-suppression time to shut down the production wells of the target heavy oil reservoir;

[0064] Once the well-steaming process is complete, the well valve is opened, and the production machine is controlled to continuously produce oil for several days on the production well of the target heavy oil reservoir until the daily oil production of the production well is less than the production threshold, after which the next single-cycle churn-and-purge process begins.

[0065] In this embodiment of the application, the specific steps of the viscosity-reducing substance injection process in the production well of the target heavy oil reservoir are as follows: sequentially injecting oil-soluble viscosity reducer (0.5-0.7 times the total amount of oil-soluble viscosity reducer), N2 (0.3-0.65 times the total amount of N2), CO2 (0.3-0.65 times the total amount of CO2), N2 (0.3-0.65 times the total amount of N2), CO2 (0.3-0.65 times the total amount of CO2), oil-soluble viscosity reducer (0.5-0.3 times the total amount of oil-soluble viscosity reducer), and N2 (0.05-0.1 times the total amount of N2). The injection intensity of CO2 is 25-100 t / m, and the injection rate is 40-70 t / d. The injection intensity of the oil-soluble viscosity reducer is 0.7-1.5 t / m, and the injection rate is 3-4 t / h. The CO2:N2 injection volume ratio is 2:1, and the N2 injection rate is 8000-12500 m³ / h. 3 / d.

[0066] It should be noted that, firstly, an oil-soluble viscosity reducer is injected at the production wellhead. This allows the subsequently injected carbon dioxide to preferentially react with the oil-soluble viscosity reducer, preventing asphaltene deposition caused by carbon dioxide and heavy oil extraction, which could clog the wellhead conduit. Simultaneously, sufficient carbon dioxide is added to the production well to reduce the viscosity of the heavy oil, making it more fluid. Since the driving force of carbon dioxide is limited, some deep, difficult-to-reach areas exist. Injecting nitrogen into the production well rapidly expands and generates a certain driving force, propelling the carbon dioxide to reduce the viscosity of the heavy oil in these less accessible areas far from the wellbore and promoting its flow. Next, an oil-soluble viscosity reducer is injected again into the production well to prevent asphaltene deposition caused by carbon dioxide extraction from clogging the wellhead conduit again. Finally, a small amount of nitrogen is injected into the production well. Due to the low density of nitrogen, the mixed system can be pushed deeper into the target heavy oil reservoir, improving oil displacement efficiency.

[0067] After the injection of viscosity-reducing substances into the production well of the target heavy oil reservoir is completed, the well is shut off to allow the injected oil displacement medium and viscosity-reducing substances to interact better with the heavy oil, thereby promoting the flow and extraction of the heavy oil.

[0068] After the set well-closing time is reached, the production well is opened for continuous production for several days. When the daily oil production of a single production well is less than the preset oil production threshold, the next round of injection and churn is carried out, repeating the same steps of the production well viscosity-reducing material injection process, well-closing process, and well-opening production process.

[0069] See Figure 3 This diagram illustrates the distribution of the injection media (i.e., oil displacement medium, viscosity reducer, and water) within the oil reservoir during a single-cycle injection / pump process. Near the injection well, there is a slug glycerol-water solution and carbon dioxide, while near the production well, there is a slug oil-soluble viscosity reducer, carbon dioxide, and nitrogen.

[0070] S120. During the well-steaming and well-opening production processes of the production well in the target heavy oil reservoir, the injection machine is controlled to inject the viscosity-reducing substance into the slug of the production well in the target heavy oil reservoir until the production well in the target heavy oil reservoir completes a preset number of single-round inrush and outrushes.

[0071] In this embodiment of the application, based on multiple factors such as mining effect assessment, mining cost assessment, and reservoir status assessment, the number of times a single round of production wells in the target heavy oil reservoir is determined, i.e., the value of the preset number of times, which is usually 2 or 3.

[0072] After the production well completes the preset number of single-round churn-and-purge processes, the injection of viscosity-reducing substances into the sluice plug of the production well in the target heavy oil reservoir is stopped, and then the well-clogging process and the well-opening production process are repeated.

[0073] As the number of single-cycle injections in a production well increases, the radius of the injection front expands further into the oil layer, reaching a maximum of 50-70m.

[0074] See Figure 4 This diagram illustrates the distribution of the injected medium (i.e., oil displacement medium, viscosity-reducing substance, and water) within the oil reservoir after completing a predetermined number of single-round injection and churn processes. Near the injection well, there are slug glycerol-water solution and carbon dioxide, while the production well is shut down and there are no viscosity-reducing substances near the production well.

[0075] S130. Control the injection machine to inject the oil displacement medium into the injection well of the target heavy oil reservoir until the water cut of the production well of the target heavy oil reservoir reaches the first threshold. Control the injection machine to inject water separately into the injection well of the target heavy oil reservoir until the water cut of the production well of the target heavy oil reservoir reaches the second threshold. The exploitation of the target heavy oil reservoir ends, and the first threshold is less than the second threshold.

[0076] In this embodiment, when the water cut in the production well is high and reaches the first threshold, it indicates that there is little remaining heavy oil in the target reservoir. This allows for reduced injection costs by individually injecting water into the injection well of the target heavy oil reservoir for oil recovery. Typically, the first threshold is set to 80%. When the water cut in the production well reaches 80%, water-drive can be used in the injection well to recover the remaining heavy oil.

[0077] See Figure 5 This is a schematic diagram showing the distribution of the injected medium (i.e., oil displacement medium, viscosity reducing substance and water) in the reservoir after the water cut of the production well reaches the first threshold. There is an aqueous solution layer near the injection well.

[0078] Simultaneously, when the water cut in the production well exceeds the first threshold and reaches the second threshold, it indicates that the oil content of the target heavy oil reservoir is low and cannot be effectively extracted, and extraction of the target heavy oil reservoir should be terminated. Typically, the second threshold is set at 95%; when the water cut in the production well reaches 95%, extraction of the target heavy oil reservoir ends.

[0079] As an optional but not limited implementation method, the formula for calculating the mass of carbon dioxide injected into the injection well of the target heavy oil reservoir is as follows:

[0080]

[0081] Where m is the mass of injected CO2, t, and V are the masses of CO2 injected. S The ground volume for CO2 injection is m3; P S Atmospheric pressure under standard conditions, MPa, with a value of 0.1 MPa; T S The ground standard state temperature is ℃, taken as 20℃; M is the molecular weight of CO2, taken as 0.044 g / mole.

[0082] The formula for calculating the subsurface volume of carbon dioxide injected into a production well of a target heavy oil reservoir is as follows:

[0083]

[0084] Among them, V R The underground volume of injected CO2 is m 3 V S m is the ground volume of CO2 injected. 3 ;P R Formation pressure, MPa; T R Formation temperature, °C;

[0085] The formula for calculating the subsurface volume of nitrogen injected into a production well in a target heavy oil reservoir is as follows:

[0086]

[0087] Among them, V R For the underground volume of N2 injected, m 3 V S m is the ground volume into which N2 is injected. 3 ;P R Formation pressure, MPa; T R Formation temperature, °C;

[0088] The method for calculating the subsurface volume of water injected separately into a production well of a target heavy oil reservoir is as follows:

[0089] V RW =B W V SW;

[0090] Among them, V RW The underground volume of injected water is m 3 V SW Let m be the volume of the ground into which water is injected. 3 B W The volume factor of formation water is m. 3 / m 3 The value is 1.

[0091] In this embodiment of the application, during the actual injection of carbon dioxide, nitrogen and water into the injection well and production well, the following parameters need to be specified: the mass of carbon dioxide injected into the injection well of the target heavy oil reservoir, the underground volume of carbon dioxide injected into the production well of the target heavy oil reservoir, the underground volume of nitrogen injected into the production well of the target heavy oil reservoir, and the underground volume of water injected separately into the production well of the target heavy oil reservoir.

[0092] Specifically, the mass of carbon dioxide injected into the injection well can be determined based on the surface volume of injected carbon dioxide and the mass of carbon dioxide injected into the injection well of the target heavy oil reservoir using the calculation formula; the underground volume of carbon dioxide injected into the production well can be determined based on the surface volume of injected carbon dioxide and the underground volume of carbon dioxide injected into the production well of the target heavy oil reservoir using the calculation formula; the underground volume of nitrogen injected into the production well can be determined based on the surface volume of injected nitrogen and the underground volume of nitrogen injected into the production well of the target heavy oil reservoir using the calculation formula; and the underground volume of water injected into the production well can be determined based on the surface volume of injected water and the underground volume of water injected separately into the production well of the target heavy oil reservoir using the calculation formula.

[0093] As an optional but not limited approach, heavy oil reservoirs with underground crude oil viscosity below 1000 centipoise, permeability above 10 millidarcy, effective thickness greater than 10 meters, and oil saturation greater than 0.5 are selected.

[0094] In this embodiment of the application, the target heavy oil reservoir is a heavy oil reservoir with underground crude oil viscosity of less than 1000 cP, permeability of more than 10 mD, effective thickness of more than 10 m, and oil saturation of more than 0.5.

[0095] The heavy oil reservoir development method of the present invention is not affected by the formation water salinity and can also be applied to heavy oil reservoirs at different stages of depletion development, original undeveloped and water-drive development.

[0096] The technical solution of this invention achieves increased production and recovery rate of the target heavy oil reservoir by injecting glycerol-water solution and carbon dioxide into the injection well, and injecting oil-soluble viscosity reducer, nitrogen and carbon dioxide into the production well, and implementing injection schemes for the production well and injection well of the target heavy oil reservoir according to different conditions.

[0097] Taking a deep heavy oil reservoir in a certain area as the target heavy oil reservoir as an example, the following are the detailed steps of two specific implementation cases based on the heavy oil reservoir exploitation method.

[0098] Specific Implementation Case 1

[0099] The implementation steps for exploiting the target heavy oil reservoir are as follows:

[0100] (a) Determining the parameters of the target heavy oil reservoir: The well pattern parameters of the target heavy oil reservoir are a 170m inverse seven-point well pattern (production-injection ratio of 2:1). The basic parameters of the target heavy oil reservoir are as follows: the burial depth in the middle of the reservoir is 1050m, the average effective thickness of the oil layer is 15m, the original oil saturation is 0.68, the average porosity is 22%, the permeability is 10-100mD, the original formation pressure is 15MPa, the pressure coefficient is 1.25, the reservoir temperature is 23℃, the underground crude oil viscosity is 250cP, the degassed crude oil viscosity is 2000cP, and the degassed crude oil density is 0.925g / cm3. This reservoir was put into production in 1991. The original development method was mainly conventional water drive. After 32 years of development, the formation pressure is 10MPa, the water cut is 65%, and the water drive recovery rate is 9.53%.

[0101] (b) Injection process of oil displacement medium in injection well: The injection machine is controlled to inject 900t (498,528 m³ at standard surface conditions) of CO2 slug at 20°C into the central injection well in sequence and alternately. 3 The process involves injecting 900 tons of a glycerol-water solution slug at a temperature of 20℃, a reference concentration of 75%, and a target viscosity of 23.5 cP. The CO2 slug injection will last for 30 days, with an injection rate of 30 tons per day; the glycerol-water solution slug injection will also last for 30 days, with an injection rate of 30 tons per day.

[0102] (c) Single-cycle throughput process of production wells:

[0103] Production well viscosity-reducing substance injection process: In each production well, 10.5t of oil-soluble viscosity-reducing slug at 20℃ and 375t of CO2 slug at 20℃ (surface standard state volume 207750m³) are injected sequentially. 3 ), N2 slug at 20℃ 103875m 3 (Volume under standard conditions), 375t CO2 slug at 20℃ (Ground standard condition volume 207750m³) 3 ), N2 slug at 20℃ 93488m 3 (Volume under standard conditions), 4.5t of oil-soluble viscosity reducer slug at 20℃, and 10387m³ of N2 slug at 20℃. 3(Volume under standard conditions); The injection times for each segment plug are 3 hours, 7 days, 10 days, 7 days, 10 days, 1.5 hours, and 1 day, respectively.

[0104] Production well shut-off process: Injection wells continuously inject oil displacement medium, while production wells stop injecting viscosity-reducing substances and shut off for 25 days;

[0105] Production well start-up process: Continue to inject oil into the injection well according to the oil displacement medium injection process. The production well starts continuous production. When the daily oil production of a single production well drops below 2t / d, the production well stops production and enters the next single cycle of huff and puff process.

[0106] (d) Production well injection stop: After the production well completes a preset number of 2 single-round injection and spitting processes, the viscosity-reducing substance injection process of the production well stops, and production resumes after the well is shut down;

[0107] (e) Water injection in injection wells: When the water cut of the production well is greater than 80%, the injection wells stop injecting oil displacement medium and switch to water injection only, with a water injection rate of 30t / d, while the production wells continue to produce.

[0108] (f) End of production: When the water cut of the production well is greater than 95%, the injection well stops water injection production, and the production of the target heavy oil reservoir ends.

[0109] See Figure 6 This is a comparison curve of production rates between the heavy oil reservoir development method and conventional waterflooding in the target heavy oil reservoir. Before implementing the heavy oil reservoir development method of this invention, the daily oil production per well in conventional waterflooding had dropped to about 1 t / d. After implementing the heavy oil reservoir development method of this invention, the daily oil production per well increased significantly, with the peak daily oil production after implementation being about three times that before implementation. It is predicted that by continuing conventional waterflooding development until 2050, the final recovery rate will be 11.51%. Based on the heavy oil reservoir development method of this invention, it is predicted that by developing until 2050, the final recovery rate will be 29.4%, representing a 17.8% improvement in recovery compared to conventional waterflooding development.

[0110] Specific Implementation Case 2

[0111] The implementation steps for exploiting the target heavy oil reservoir are as follows:

[0112] (a) Determining the parameters of the target heavy oil reservoir: The well network parameters of the target heavy oil reservoir are a reverse nine-point well network with an injection-production well spacing of 100m × 140m (production-injection ratio 3:1). The basic parameters of the target heavy oil reservoir are as follows: the burial depth in the middle of the reservoir is 1150m, the average effective thickness of the oil layer is 10m, the original oil saturation is 0.65, the average porosity is 21%, the permeability is 50-100mD, the original formation pressure is 11MPa, the pressure coefficient is 1.0, the reservoir temperature is 25℃, the underground crude oil viscosity is 500cP, the degassed crude oil viscosity is 4000cP, and the degassed crude oil density is 0.96g / cm3. This target heavy oil reservoir was put into production in 2021. The original development method was mainly natural gas huff and puff. After 3 years of development, the formation pressure is 7MPa, the water cut is 5%, and the recovery rate is 5%.

[0113] (b) Injection process of oil displacement medium in injection well: The injection machine is controlled to inject 450t (166200m³ of CO2 slug at 20°C) into the central injection well in sequence and alternately. 3 300t of glycerol-water solution slugs were prepared at a temperature of 20℃, a reference concentration of 80%, and a target viscosity of 41cP. The CO2 slug injection was carried out for 30 days at a rate of 15t / day; the glycerol-water solution slug injection was carried out for 30 days at a rate of 10t / day.

[0114] (c) Single-cycle throughput process of production wells:

[0115] Production well viscosity-reducing substance injection process: In each production well, 5.6t of oil-soluble viscosity-reducing slug at 20℃ and 350t of CO2 slug at 20℃ (surface standard state volume 193,900 m³) are injected sequentially. 3 ), N2 slug at 20℃ 116340m 3 (Volume under standard conditions), 350t CO2 slug at 20℃ (Ground standard condition volume 207750m³) 3 ), N2 slug at 20℃ 58170m 3 (Volume under standard conditions), 4.5t of oil-soluble viscosity reducer slug at 20℃, and 19390m of N2 slug at 20℃. 3 (Volume under standard conditions); The injection times for each segment plug are 3 hours, 7 days, 10 days, 7 days, 10 days, 1.5 hours, and 1 day, respectively.

[0116] Production well shut-off process: Injection wells continuously inject oil displacement medium, while production wells stop injecting viscosity-reducing substances and shut off for 25 days;

[0117] Production well start-up process: Continue to inject oil into the injection well according to the oil displacement medium injection process. The production well starts continuous production. When the daily oil production of a single production well drops below 2t / d, the production well stops production and enters the next single cycle of huff and puff process.

[0118] (d) Production well injection stop: After the production well completes a preset number of 3 single-round injection and spitting processes, the viscosity-reducing substance injection process of the production well stops, and production resumes after the well is shut down;

[0119] (e) Water injection in injection wells: When the water cut of the production well is greater than 80%, the injection wells stop injecting oil displacement medium and switch to water injection only, with a water injection rate of 30t / d, while the production wells continue to produce.

[0120] (f) End of production: When the water cut of the production well is greater than 95%, the injection well stops water injection production, and the production of the target heavy oil reservoir ends.

[0121] See Figure 7 This is a comparison curve showing the production rates of heavy oil reservoir development using the present invention and the development of target heavy oil reservoirs using natural gas huff and puff. Before implementing the heavy oil reservoir development method of the present invention, the daily oil production from natural gas huff and puff had decreased to about 2 t / d. After implementing the heavy oil reservoir development method of the present invention, the daily oil production per well increased significantly, with the peak daily oil production after implementation being about 1.8 times that before implementation. It is predicted that with continued development using natural gas huff and puff until 2050, the final recovery rate will be 17.3%. Based on the heavy oil reservoir development method of the present invention, it is predicted that with development until 2050, the final recovery rate will be 50.6%, representing a 33.3% increase in recovery compared to natural gas huff and puff development.

[0122] Example 2

[0123] Figure 8 This is a schematic diagram of a heavy oil reservoir extraction device provided in Embodiment 2 of the present invention.

[0124] like Figure 8 As shown, the device includes:

[0125] Injection module 310 is used to control the injection machine to inject oil displacement medium into the injection well of the target heavy oil reservoir and to control the injection machine to inject viscosity-reducing substance into the production well of the target heavy oil reservoir; wherein, the oil displacement medium includes glycerol-water solution and carbon dioxide, and the viscosity-reducing substance includes oil-soluble viscosity reducer, nitrogen and carbon dioxide, and the injection well and production well of the target heavy oil reservoir are connected by a bottom channel so that the production oil from the injection well flows to the production well;

[0126] The production well constraint module 320 is used to control the injection machine to inject viscosity-reducing substances into the slug of the production well in the target heavy oil reservoir during the well shut-in and well opening production processes, until the production well of the target heavy oil reservoir completes a preset number of single-round inrush and out.

[0127] The injection well constraint module 330 is used to control the injection machine to inject the oil displacement medium into the injection well of the target heavy oil reservoir until the water cut of the production well of the target heavy oil reservoir reaches a first threshold, and to control the injection machine to inject water separately into the injection well of the target heavy oil reservoir until the water cut of the production well of the target heavy oil reservoir reaches a second threshold, and the exploitation of the target heavy oil reservoir ends. The first threshold is less than the second threshold.

[0128] Based on the above embodiments, optionally, the injection module 310 of the injection-production well includes:

[0129] The injection well injection unit is used to control the injection machine to alternately inject a reference concentration of glycerol-water solution and carbon dioxide into the slug of the injection well in the target heavy oil reservoir. The reference concentration represents the mass concentration of glycerol in water.

[0130] Based on the above embodiments, optionally, the injection well injection unit includes:

[0131] The target viscosity determination subunit is used to determine the target viscosity of the glycerol-water solution, which represents the viscosity value at which the sweep efficiency of the glycerol-water solution is at its highest.

[0132] The reference concentration determination subunit is used to determine the reference concentration of the injected glycerol-water solution based on the target viscosity;

[0133] The injection subunit is used to control the injection machine to alternately inject the reference concentration of glycerol-water solution and carbon dioxide into the injection well slug of the target heavy oil reservoir.

[0134] Based on the above embodiments, optionally, the injection module 310 of the injection-production well includes:

[0135] A single-round injection unit is used to control the injection machine to alternately inject viscosity-reducing substances into the slug of the production well of the target heavy oil reservoir in multiple single-round injection processes; the single-round injection process includes the viscosity-reducing substance injection process, the well-clogging process, and the well-opening production process.

[0136] Based on the above embodiments, optionally, the single-round throughput unit includes:

[0137] The production well injection subunit is used to control the injection machine to inject oil-soluble viscosity reducer into the production well of the target heavy oil reservoir, control the injection machine to alternately inject carbon dioxide and nitrogen into the production well of the target heavy oil reservoir, control the injection machine to inject oil-soluble viscosity reducer into the production well of the target heavy oil reservoir, and finally inject nitrogen into the production well of the target heavy oil reservoir, thus ending the viscosity reducer injection process of the production well of the target heavy oil reservoir.

[0138] The production well shut-off unit is used to control the closure of well valves according to the shut-off time to shut off the production wells of the target heavy oil reservoir.

[0139] The production well extraction subunit is used to control the well valve to open after the well shut-in process ends, and to control the oil production machine to continuously produce oil for several days on the production well of the target heavy oil reservoir until the daily oil production of the production well is less than the oil production threshold, and then to carry out the next single-round churn process.

[0140] Based on the above embodiments, optionally, the formula for calculating the mass of carbon dioxide injected into the injection well of the target heavy oil reservoir is as follows:

[0141]

[0142] Where m is the mass of injected CO2, t, and V are the masses of CO2 injected. S m is the ground volume of CO2 injected. 3 ;P S Atmospheric pressure under standard conditions, MPa, with a value of 0.1 MPa; T S The ground standard state temperature is ℃, taken as 20℃; M is the molecular weight of CO2, taken as 0.044 g / mole.

[0143] The formula for calculating the subsurface volume of carbon dioxide injected into a production well of a target heavy oil reservoir is as follows:

[0144]

[0145] Among them, V R The underground volume of injected CO2 is m 3 V S m is the ground volume of CO2 injected. 3 ;P R Formation pressure, MPa; T R Formation temperature, °C;

[0146] The formula for calculating the subsurface volume of nitrogen injected into a production well in a target heavy oil reservoir is as follows:

[0147]

[0148] Among them, V RFor the underground volume of N2 injected, m 3 V S m is the ground volume into which N2 is injected. 3 ;P R Formation pressure, MPa; T R Formation temperature, °C;

[0149] The method for calculating the subsurface volume of water injected separately into a production well in a heavy oil reservoir is as follows:

[0150] V RW =B W V SW ;

[0151] Among them, V RW The underground volume of injected water is m 3 V SW Let m be the volume of the ground into which water is injected. 3 B W The volume factor of formation water is m. 3 / m 3 The value is 1.

[0152] Based on the above embodiments, optionally, heavy oil reservoirs with underground crude oil viscosity below 1000 centipoise, permeability above 10 millidarcy, effective thickness greater than 10 meters, and oil saturation greater than 0.5 can be screened.

[0153] The heavy oil reservoir extraction apparatus provided in the embodiments of the present invention can execute the heavy oil reservoir extraction method provided in any embodiment of the present invention, and has the corresponding functional modules and beneficial effects of the method.

[0154] Example 3

[0155] Figure 9 A schematic diagram of an electronic device 10 that can be used to implement embodiments of the present invention is shown. The electronic device is intended to represent various forms of digital computers, such as laptop computers, desktop computers, workstations, personal digital assistants, servers, blade servers, mainframe computers, and other suitable computers. The electronic device can also represent various forms of mobile devices, such as personal digital processors, cellular phones, smartphones, wearable devices (e.g., helmets, glasses, watches, etc.), and other similar computing devices. The components shown herein, their connections and relationships, and their functions are merely illustrative and are not intended to limit the implementation of the invention described and / or claimed herein.

[0156] like Figure 9As shown, the electronic device 10 includes at least one processor 11 and a memory, such as a read-only memory (ROM) 12 or a random access memory (RAM) 13, communicatively connected to the at least one processor 11. The memory stores computer programs executable by the at least one processor. The processor 11 can perform various appropriate actions and processes based on the computer program stored in the ROM 12 or loaded from storage unit 18 into the RAM 13. The RAM 13 may also store various programs and data required for the operation of the electronic device 10. The processor 11, ROM 12, and RAM 13 are interconnected via a bus 14. An input / output (I / O) interface 15 is also connected to the bus 14.

[0157] Multiple components in electronic device 10 are connected to I / O interface 15, including: input unit 16, such as keyboard, mouse, etc.; output unit 17, such as various types of displays, speakers, etc.; storage unit 18, such as disk, optical disk, etc.; and communication unit 19, such as network card, modem, wireless transceiver, etc. Communication unit 19 allows electronic device 10 to exchange information / data with other devices through computer networks such as the Internet and / or various telecommunications networks.

[0158] Processor 11 can be a variety of general-purpose and / or special-purpose processing components with processing and computing capabilities. Some examples of processor 11 include, but are not limited to, a central processing unit (CPU), a graphics processing unit (GPU), various special-purpose artificial intelligence (AI) computing chips, various processors running machine learning model algorithms, a digital signal processor (DSP), and any suitable processor, controller, microcontroller, etc. Processor 11 performs the various methods and processes described above, such as heavy oil reservoir exploitation methods.

[0159] In some embodiments, the heavy oil reservoir exploitation method may be implemented as a computer program tangibly contained in a computer-readable storage medium, such as storage unit 18. In some embodiments, part or all of the computer program may be loaded and / or installed on electronic device 10 via ROM 12 and / or communication unit 19. When the computer program is loaded into RAM 13 and executed by processor 11, one or more steps of the heavy oil reservoir exploitation method described above may be performed. Alternatively, in other embodiments, processor 11 may be configured to perform the heavy oil reservoir exploitation method by any other suitable means (e.g., by means of firmware).

[0160] Various embodiments of the systems and techniques described above herein can be implemented in digital electronic circuit systems, integrated circuit systems, field-programmable gate arrays (FPGAs), application-specific integrated circuits (ASICs), application-specific standard products (ASSPs), systems-on-a-chip (SoCs), payload-programmable logic devices (CPLDs), computer hardware, firmware, software, and / or combinations thereof. These various embodiments may include implementations in one or more computer programs that can be executed and / or interpreted on a programmable system including at least one programmable processor, which may be a dedicated or general-purpose programmable processor, capable of receiving data and instructions from a storage system, at least one input device, and at least one output device, and transmitting data and instructions to the storage system, the at least one input device, and the at least one output device.

[0161] Computer programs used to implement the methods of the present invention may be written in any combination of one or more programming languages. These computer programs may be provided to a processor of a general-purpose computer, a special-purpose computer, or other programmable data processing device, such that when executed by the processor, the computer programs cause the functions / operations specified in the flowcharts and / or block diagrams to be performed. The computer programs may be executed entirely on a machine, partially on a machine, or as a standalone software package, partially on a machine and partially on a remote machine, or entirely on a remote machine or server.

[0162] In the context of this invention, a computer-readable storage medium can be a tangible medium that may contain or store a computer program for use by or in conjunction with an instruction execution system, apparatus, or device. A computer-readable storage medium may include, but is not limited to, electronic, magnetic, optical, electromagnetic, infrared, or semiconductor systems, apparatus, or devices, or any suitable combination thereof. Alternatively, a computer-readable storage medium may be a machine-readable signal medium. More specific examples of machine-readable storage media include electrical connections based on one or more wires, portable computer disks, hard disks, random access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM or flash memory), optical fibers, portable compact disk read-only memory (CD-ROM), optical storage devices, magnetic storage devices, or any suitable combination thereof.

[0163] To provide interaction with a user, the systems and techniques described herein can be implemented on an electronic device having: a display device (e.g., a CRT (cathode ray tube) or LCD (liquid crystal display) monitor) for displaying information to the user; and a keyboard and pointing device (e.g., a mouse or trackball) through which the user provides input to the electronic device. Other types of devices can also be used to provide interaction with the user; for example, feedback provided to the user can be any form of sensory feedback (e.g., visual feedback, auditory feedback, or tactile feedback); and input from the user can be received in any form (including sound input, voice input, or tactile input).

[0164] The systems and technologies described herein can be implemented in computing systems that include backend components (e.g., as data servers), or computing systems that include middleware components (e.g., application servers), or computing systems that include frontend components (e.g., user computers with graphical user interfaces or web browsers through which users can interact with implementations of the systems and technologies described herein), or any combination of such backend, middleware, or frontend components. The components of the system can be interconnected via digital data communication of any form or medium (e.g., communication networks). Examples of communication networks include local area networks (LANs), wide area networks (WANs), blockchain networks, and the Internet.

[0165] A computing system can include clients and servers. Clients and servers are generally located far apart and typically interact through communication networks. The client-server relationship is created by computer programs running on the respective computers and having a client-server relationship with each other. The server can be a cloud server, also known as a cloud computing server or cloud host, which is a hosting product within the cloud computing service system to address the shortcomings of traditional physical hosts and VPS services, such as high management difficulty and weak business scalability.

[0166] It should be understood that the various forms of processes shown above can be used, with steps reordered, added, or deleted. For example, the steps described in this invention can be executed in parallel, sequentially, or in different orders, as long as the desired result of the technical solution of this invention can be achieved, and this is not limited herein.

[0167] The specific embodiments described above do not constitute a limitation on the scope of protection of this invention. Those skilled in the art should understand that various modifications, combinations, sub-combinations, and substitutions can be made according to design requirements and other factors. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this invention should be included within the scope of protection of this invention.

Claims

1. A method for exploiting heavy oil reservoirs, characterized in that, include: The injection machine is controlled to inject an oil displacement medium into the injection well of the target heavy oil reservoir, and to inject a viscosity-reducing substance into the production well of the target heavy oil reservoir. The oil displacement medium includes glycerol-water solution and carbon dioxide, and the viscosity-reducing substance includes oil-soluble viscosity reducer, nitrogen and carbon dioxide. The injection well and production well of the target heavy oil reservoir are connected by a bottom channel so that the production oil from the injection well flows to the production well. During the well-steaming and well-opening production processes of the production well in the target heavy oil reservoir, the injection machine is controlled to inject the viscosity-reducing substance into the slug of the production well in the target heavy oil reservoir until the production well in the target heavy oil reservoir completes a preset number of single-round inrush and outrushes. The injection machine is controlled to inject the oil displacement medium into the injection well of the target heavy oil reservoir until the water cut of the production well of the target heavy oil reservoir reaches a first threshold. The injection machine is then controlled to inject water separately into the injection well of the target heavy oil reservoir until the water cut of the production well of the target heavy oil reservoir reaches a second threshold. The exploitation of the target heavy oil reservoir ends when the first threshold is less than the second threshold.

2. The method according to claim 1, characterized in that, The controlled injection machine injects glycerol-water solution and carbon dioxide into the injection well of the target heavy oil reservoir, including: The injection machine is controlled to alternately inject a reference concentration of glycerol-water solution and carbon dioxide into the slug of the injection well in the target heavy oil reservoir. The reference concentration represents the mass concentration of glycerol in water.

3. The method according to claim 2, characterized in that, The injection machine is controlled to alternately inject a reference concentration of glycerol-water solution and carbon dioxide into the sluice of the injection well in the target heavy oil reservoir, including: Determine the target viscosity of the glycerol-water solution, where the target viscosity represents the viscosity value at which the sweep efficiency of the glycerol-water solution is highest; The reference concentration of the injected glycerol-water solution is determined based on the target viscosity; The injection machine is controlled to alternately inject the reference concentration of glycerol-water solution and carbon dioxide into the slug of the injection well in the target heavy oil reservoir.

4. The method according to claim 1, characterized in that, Controlled injection machinery injects viscosity-reducing substances into production wells of target heavy oil reservoirs, including: The injection machine is controlled to alternately inject viscosity-reducing substances into the slug of the production well in the target heavy oil reservoir in multiple single-round huff and puff processes; the single-round huff and puff process includes the viscosity-reducing substance injection process, the well shut-in process, and the well opening and production process.

5. The method according to claim 4, characterized in that, The single-round throughput process includes: The injection machine is controlled to inject an oil-soluble viscosity reducer into the production well of the target heavy oil reservoir. Carbon dioxide and nitrogen are alternately injected into the production well of the target heavy oil reservoir. Finally, nitrogen is injected into the production well of the target heavy oil reservoir, and the viscosity reducer injection process of the production well of the target heavy oil reservoir is completed. The well valves are closed according to the well-suppression time to shut down the production wells of the target heavy oil reservoir; Once the well-steaming process is complete, the well valve is opened, and the production machine is controlled to continuously produce oil for several days on the production well of the target heavy oil reservoir until the daily oil production of the production well is less than the production threshold, after which the next single-cycle churn-and-purge process begins.

6. The method according to claim 1, characterized in that, The formula for calculating the mass of carbon dioxide injected into the injection well of the target heavy oil reservoir is as follows: Where m is the mass of injected CO2, t, and V are the masses of CO2 injected. S m is the ground volume of CO2 injected. 3 ;P S Atmospheric pressure under standard conditions, MPa, with a value of 0.1 MPa; T S The ground standard state temperature is ℃, taken as 20℃; M is the molecular weight of CO2, taken as 0.044 g / mole. The formula for calculating the subsurface volume of carbon dioxide injected into a production well of a target heavy oil reservoir is as follows: Among them, V R The underground volume of injected CO2 is m 3 V S m is the ground volume of CO2 injected. 3 ;P R Formation pressure, MPa; T R Formation temperature, °C; The formula for calculating the subsurface volume of nitrogen injected into a production well in a target heavy oil reservoir is as follows: Among them, V R For the underground volume of N2 injected, m 3 V S m is the ground volume into which N2 is injected. 3 ;P R Formation pressure, MPa; T R Formation temperature, °C; The method for calculating the subsurface volume of water injected separately into a production well in a heavy oil reservoir is as follows: V RW =B W V SW Among them, V RW The underground volume of injected water is m 3 V SW Let m be the volume of the ground into which water is injected. 3 B W The volume factor of formation water is m. 3 / m 3 The value is 1.

7. The method according to claim 1, characterized in that, Heavy oil reservoirs with underground crude oil viscosity below 1000 centipoise, permeability above 10 millidarcy, effective thickness greater than 10 meters, and oil saturation greater than 0.5 are selected.

8. A heavy oil reservoir extraction apparatus, characterized in that, include: The injection module for injection wells is used to control the injection machine to inject oil-displacing media into the injection well of the target heavy oil reservoir and to control the injection machine to inject viscosity-reducing substances into the production well of the target heavy oil reservoir. The oil-displacing media includes glycerol-water solution and carbon dioxide, and the viscosity-reducing substances include oil-soluble viscosity reducers, nitrogen and carbon dioxide. The injection well and production well of the target heavy oil reservoir are connected by a bottom channel so that the production oil from the injection well flows to the production well. The production well constraint module is used to control the injection machine to inject viscosity-reducing substances into the slug of the production well in the target heavy oil reservoir during the well shut-in and well opening processes, until the production well in the target heavy oil reservoir completes a preset number of single-round inrush and out. The injection well constraint module is used to control the injection machine to inject the oil displacement medium into the injection well of the target heavy oil reservoir until the water cut of the production well of the target heavy oil reservoir reaches a first threshold, and to control the injection machine to inject water separately into the injection well of the target heavy oil reservoir until the water cut of the production well of the target heavy oil reservoir reaches a second threshold, and the exploitation of the target heavy oil reservoir ends. The first threshold is less than the second threshold.

9. An electronic device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that, When the processor executes the program, it implements the method for exploiting heavy oil reservoirs as described in any one of claims 1-7.

10. A storage medium for storing computer-executable instructions, characterized in that, The computer-executable instructions, when executed by a computer processor, are used to perform the method for exploiting heavy oil reservoirs as described in any one of claims 1-7.

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