Shale in-situ heating and hydrocarbon drainage pipeline anti-clogging method, device and related system

Abstract

The application discloses a shale in-situ heating and hydrocarbon discharge pipeline anti-blocking method and device and a related system. The device comprises at least two hydrocarbon discharge branches connected with a reaction kettle, a branch control valve, an inner hydrocarbon discharge pipe and an outer hydrocarbon discharge pipe, the inner hydrocarbon discharge pipe is fixedly installed on the reaction kettle, and the outer hydrocarbon discharge pipe is detachably installed outside the reaction kettle; a total hydrocarbon discharge pipeline connected with the at least two hydrocarbon discharge branches; a first pressure detection unit for detecting the pressure in the reaction kettle; and a second pressure detection unit for detecting the pressure in the total hydrocarbon discharge pipeline. In a system working state, the branch control valve of at least one hydrocarbon discharge branch is opened, and if it is determined that the hydrocarbon discharge branch is blocked according to the pressure in the reaction kettle, the pressure in the total hydrocarbon discharge pipeline and a set hydrocarbon discharge pressure of the total hydrocarbon discharge pipeline, at least one other hydrocarbon discharge branch is selected to open the branch control valve for switching. The shale in-situ heating process can be ensured to be in a smooth state, and experimental failure and experimental safety accidents can be avoided.

Description

Technical Field

[0001] This invention relates to the field of shale oil and gas exploration and development technology, and in particular to a method, device and related system for preventing blockage of shale in-situ heated hydrocarbon removal pipelines. Background Technology

[0002] Shale oil is currently one of the most significant growth drivers in oil production. The organic-rich shale formations in China can be broadly categorized into two types: ancient marine shale formations in the south and continental Mesozoic-Cenozoic shale formations in the north. The ancient marine shale formations in the south have high maturity (Ro>2.0%) and are the main shale gas producing areas in my country. The shale formations widely developed in the north, except for a few basins with limited areas having a maturity greater than 1.3%, are mostly in the medium to low maturity stage. Due to their relatively low maturity, the organic matter content is low, resulting in crude oil with high heavy component content, high specific gravity, high viscosity, and a low gas-oil ratio, making them unsuitable for direct extraction. They are more suitable for shale oil and gas development through in-situ heating. Whether a specific low-mature shale formation is suitable for shale oil development, and determining the optimal temperature and pressure conditions for in-situ heating shale oil development, requires pilot simulation experiments. These experiments will determine the optimal temperature and pressure conditions during in-situ heating shale extraction, providing a reference for the efficient development of shale oil and gas through in-situ heating. Summary of the Invention

[0003] In shale in-situ heating simulation experiments, to reduce crude oil adsorption in the hydrocarbon discharge pipeline, the pipeline is typically designed and manufactured to be quite narrow. However, blockages frequently occur in the discharge pipeline during the experiment. Since shale in-situ heating involves heating the original rock sample, which contains water containing dissolved salts, particularly carbonates, these dissolved salts evaporate slowly with the steam and precipitate in the lower-temperature discharge pipeline, similar to limescale in a kettle. This blockage can lead to the failure of the entire in-situ heating experiment and even experimental safety accidents. Therefore, effectively preventing the blockage of the hydrocarbon discharge pipeline by shale in-situ heating products during shale in-situ heating simulation experiments is a pressing technical problem that needs to be solved.

[0004] In view of the above problems, the present invention is proposed to provide a method, apparatus and related system for preventing blockage of shale in-situ heating and hydrocarbon removal pipelines that overcomes or at least partially solves the above problems.

[0005] This invention provides an anti-clogging device for shale in-situ heating and hydrocarbon removal pipelines, comprising:

[0006] At least two hydrocarbon discharge branches are connected to the reactor. Each hydrocarbon discharge branch includes an internal hydrocarbon discharge pipe and an external hydrocarbon discharge pipe connected by a branch control valve. The internal hydrocarbon discharge pipe can be fixedly installed on the reactor, and the external hydrocarbon discharge pipe can be detachably installed outside the reactor.

[0007] A main hydrocarbon discharge pipeline connecting at least two hydrocarbon discharge branches;

[0008] A first pressure detection unit for detecting the pressure inside the reactor is installed on the reactor.

[0009] A second pressure detection unit is installed on the main hydrocarbon discharge pipeline to detect the pressure of the main hydrocarbon discharge pipeline;

[0010] When the system is in operation, at least one branch control valve of the hydrocarbon discharge branch is open, and the branch control valves of other hydrocarbon discharge branches are closed. If the difference between the pressure inside the reactor and the preset hydrocarbon discharge pressure threshold is greater than the set differential pressure threshold, and the total hydrocarbon discharge pipeline pressure is less than or equal to the hydrocarbon discharge pressure threshold, it is determined that the hydrocarbon discharge branch with the open branch control valve is blocked, and at least one other hydrocarbon discharge branch is selected to open its branch control valve for switching.

[0011] In some optional embodiments, the inner diameter of the internal hydrocarbon discharge pipe is larger than the inner diameter of the external hydrocarbon discharge pipe, or the ratio of the inner diameter of the internal hydrocarbon discharge pipe to the inner diameter of the external hydrocarbon discharge pipe is greater than 2; the branch control valve has a larger diameter at one end connected to the internal hydrocarbon discharge pipe and a smaller diameter at the other end connected to the external hydrocarbon discharge pipe.

[0012] In some optional embodiments, the inner diameter of the internal hydrocarbon discharge pipe is 8-10 mm, and the inner diameter of the external hydrocarbon discharge pipe is 3-6 mm.

[0013] In some optional embodiments, a solenoid valve is provided on the main hydrocarbon discharge line, and a multi-way valve is provided between the main hydrocarbon discharge line and at least two hydrocarbon discharge branches.

[0014] In some optional embodiments, the above method further includes:

[0015] A third pressure detection unit is installed on the external hydrocarbon discharge pipe of the hydrocarbon discharge branch to detect the pressure of the hydrocarbon discharge branch. Based on the pressure of the hydrocarbon discharge branch, the pressure inside the reactor and the pressure of the total hydrocarbon discharge pipeline, it can determine whether the hydrocarbon discharge branch with the branch control valve open is blocked and locate the location of the blockage, and determine whether the hydrocarbon discharge branch with the control valve closed is in a cut-off state.

[0016] In some optional embodiments, a reducing three-way valve is provided on the side wall of the reactor body, and the internal hydrocarbon discharge pipe and the external hydrocarbon discharge pipe are connected through the three-way valve. The spiral rod on the three-way valve can control the connection and disconnection between the internal hydrocarbon discharge pipe and the external hydrocarbon discharge pipe.

[0017] This invention provides an in-situ shale heating system for preventing blockage of hydrocarbon discharge pipelines, characterized in that it includes: a reaction vessel, a control device, and the aforementioned in-situ shale heating hydrocarbon discharge pipeline anti-blockage device;

[0018] The control device is used to acquire the pressure inside the reactor detected by the first pressure detection unit and the total hydrocarbon discharge pipeline pressure detected by the second pressure detection unit, and to determine whether the hydrocarbon discharge branch opened by the branch control valve is blocked based on the pressure inside the reactor, the total hydrocarbon discharge pipeline pressure and the preset hydrocarbon discharge pressure threshold.

[0019] In some optional embodiments, the control device is further configured to:

[0020] The pressure of the hydrocarbon discharge branch detected by the third pressure detection unit on the external hydrocarbon discharge pipe of the control valve-opened hydrocarbon discharge branch is obtained. Based on the hydrocarbon discharge branch pressure, the pressure inside the reactor and the total hydrocarbon discharge pipeline pressure, it is determined whether the hydrocarbon discharge branch with the control valve open is blocked and the location of the blockage is located, and it is determined whether the hydrocarbon discharge branch with the control valve closed is in a cut-off state.

[0021] This invention provides a method for preventing blockage in shale in-situ heating and hydrocarbon removal pipelines, which is implemented using the aforementioned shale in-situ heating system for preventing blockage in hydrocarbon removal pipelines.

[0022] In some optional embodiments, the above method includes:

[0023] Select at least one hydrocarbon discharge branch and open its branch control valve, while keeping the branch control valves of the other hydrocarbon discharge branches closed;

[0024] The pressure inside the reactor detected by the first pressure detection unit and the pressure in the total hydrocarbon discharge pipeline detected by the second pressure detection unit are monitored in real time. If the difference between the pressure inside the reactor and the preset hydrocarbon discharge pressure threshold is greater than the set differential pressure threshold, and the pressure in the total hydrocarbon discharge pipeline is less than or equal to the hydrocarbon discharge pressure threshold, it is determined that the hydrocarbon discharge branch opened by the branch control valve is blocked.

[0025] Select a branch control valve that is closed for hydrocarbon discharge, open the branch control valve, and close the branch control valve of the blocked hydrocarbon discharge branch. Then remove its external hydrocarbon discharge pipe, clear the blockage, and reinstall it.

[0026] In some optional embodiments, the above method further includes:

[0027] Real-time monitoring of the hydrocarbon discharge branch pressure detected by the third pressure detection unit on the hydrocarbon discharge pipe of each hydrocarbon discharge branch;

[0028] Based on the pressure of the hydrocarbon discharge branch, the pressure inside the reactor, and the pressure of the total hydrocarbon discharge pipeline, it is determined whether the hydrocarbon discharge branch with the branch control valve open is blocked and the location of the blockage is located, and it is determined whether the hydrocarbon discharge branch with the control valve closed is in a cut-off state.

[0029] The beneficial effects of the above-described technical solutions provided in the embodiments of the present invention include at least the following:

[0030] The shale in-situ heating hydrocarbon removal pipeline anti-clogging device and blockage detection system provided in this invention embodiment achieves backup for the hydrocarbon removal branches by setting at least two parallel hydrocarbon removal branches. In practical applications, the branch control valve of at least one hydrocarbon removal branch is opened to connect the hydrocarbon removal branch, while the branch control valves of the other hydrocarbon removal branches are closed as backups. The blockage of the hydrocarbon removal branch is determined by detecting the pressure inside the reactor and the pressure in the hydrocarbon removal pipeline. When the connected hydrocarbon removal branch is blocked, the branch control valve of that hydrocarbon removal branch is closed, and the branch control valve of the backup hydrocarbon removal branch is opened to achieve switching of the hydrocarbon removal branch, ensuring the smooth flow of the hydrocarbon removal pipeline and the normal operation of the experiment. The external hydrocarbon removal pipe of the blocked hydrocarbon removal branch can be disassembled for cleaning and replacement so that it can be switched again in the future, ensuring that the hydrocarbon removal pipeline can always be in a normal state and avoiding experimental failures and experimental safety accidents.

[0031] Other features and advantages of the invention will be set forth in the description which follows, and will be apparent in part from the description, or may be learned by practicing the invention. The objects and other advantages of the invention may be realized and obtained by means of the structures particularly pointed out in the written description, claims, and drawings.

[0032] The technical solution of the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. Attached Figure Description

[0033] The accompanying drawings are provided to further illustrate the invention and form part of the specification. They are used in conjunction with embodiments of the invention to explain the invention and do not constitute a limitation thereof. In the drawings:

[0034] Figure 1 This is a schematic diagram of the anti-clogging system for the shale in-situ heating and hydrocarbon removal pipeline in an embodiment of the present invention;

[0035] Figure 2 This is a flowchart of the method for preventing blockage in the shale in-situ heating and hydrocarbon removal pipeline in an embodiment of the present invention;

[0036] Figure 3 This is a real-time curve of the pressure inside the reactor and the pressure in the hydrocarbon discharge pipeline recorded in the shale in-situ heating simulation experiment in this embodiment of the invention. Detailed Implementation

[0037] Exemplary embodiments of the present disclosure will now be described in more detail with reference to the accompanying drawings. While exemplary embodiments of the present disclosure are shown in the drawings, it should be understood that the present disclosure may be implemented in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the disclosure to those skilled in the art.

[0038] It should be understood that the terminology used in this invention is merely for describing particular embodiments and is not intended to limit the invention. Furthermore, with respect to numerical ranges in this invention, it should be understood that each intermediate value between the upper and lower limits of the range is also specifically disclosed. Every smaller range between any stated value or intermediate value within a stated range, and any other stated value or intermediate value within said range, is also included in this invention. The upper and lower limits of these smaller ranges may be independently included or excluded from the range.

[0039] Unless otherwise stated, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. While only preferred methods and materials have been described herein, any methods and materials similar or equivalent to those described herein may be used in the implementation or testing of this invention. All references to this specification are incorporated by way of citation to disclose and describe methods and / or materials associated with those references. In the event of any conflict with any incorporated reference, the content of this specification shall prevail.

[0040] In the description of this invention, it should be noted that the terms "comprising," "including," "having," "containing," etc., are all open-ended terms, meaning that they include but are not limited to. Furthermore, the terms "first," "second," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0041] Simulation experiments are the most important method for evaluating the oil and gas production potential of in-situ heating in medium- to low-maturity shale. The inventors have discovered that current simulation experiment methods for evaluating the oil and gas production potential of in-situ heating in medium- to low-maturity shale can be broadly classified into two categories based on sample characteristics and experimental methods:

[0042] (I) Simulation Experiment Method for Hydrocarbon Generation from Kerogen

[0043] This experimental method primarily utilizes hydrocarbon generation simulations of kerogen in a closed-loop system (like a gold tube) to infer oil and gas production during in-situ shale heating. However, in this in-situ heating process, not all the oil and gas generated from the organic matter in the shale is extracted; a significant portion (heavy components) remains undeveloped. Since the amount of oil and gas generated and the amount that can be extracted are two entirely different concepts, the kerogen hydrocarbon generation simulation method can only simulate the amount of oil and gas generated during in-situ shale heating. It cannot address questions such as how much of the generated oil and gas can be extracted, its composition, or the optimal temperature for extraction. Therefore, the results of hydrocarbon generation simulations are of limited reference value for evaluating the oil and gas production potential of in-situ shale heating, determining the optimal heating rate, and selecting the optimal heating temperature and pressure.

[0044] (II) Hydrocarbon generation and expulsion simulation experiment method

[0045] This experimental method primarily utilizes hydrocarbon generation and expulsion simulation equipment to evaluate the potential of in-situ shale heating for oil and gas development based on oil and gas production data from shale samples under specific static and hydrocarbon expulsion pressures during heating. This method can be further categorized into two types based on the characteristics of the shale samples:

[0046] (1) Simulation of hydrocarbon generation and expulsion in dried shale samples

[0047] The simulated experimental samples underwent low-temperature drying before the experiment to completely evaporate the moisture in the original shale samples. However, this resulted in significant differences between the laboratory experimental samples and the samples from the oilfield. In the in-situ heating simulation experiment, the shale contained a certain amount of water. For example, the heating temperature range for in-situ heating of shale for oil and gas development in a certain area is 250-450℃. The presence of formation water affects the hydrocarbon generation capacity of shale, and also affects the hydrocarbon production (and expulsion) efficiency of shale. This is mainly manifested in the following aspects: ① Numerous simulation experiments have shown that water reacts with the organic matter in shale under relatively high temperature conditions (>300℃) to generate a large amount of CO2, while reducing the hydrocarbon generation capacity of the organic matter; ② The water in the original shale contains various metal ions (such as Mg). 2+ The drying process significantly impacts oil and gas generation and crude oil cracking (e.g., TSR), thus affecting the oil and gas production temperature, quantity, and properties of shale in-situ heating. Furthermore, moisture in the original shale readily vaporizes during in-situ heating, increasing the pressure within the experimental system and consequently affecting oil and gas production. For these reasons, the experimental results obtained using dried shale samples have significantly reduced reference value for in-situ shale oil and gas development.

[0048] (2) Heating simulation of undried original shale samples

[0049] Undried virgin shale samples more closely resemble the original characteristics of shale underground. Therefore, indoor heating simulation data from virgin shale samples are more valuable for in-situ heating development of shale oil and gas. However, virgin shale under formation conditions contains formation water, which contains salts (especially carbonates). During the heating process, these dissolved salts evaporate slowly with the water vapor and precipitate in the low-temperature hydrocarbon removal pipeline (like scale). This can clog small-diameter hydrocarbon removal pipes, hindering the process and causing the entire in-situ heating experiment to fail, or even leading to safety accidents. Therefore, a major problem that needs to be addressed in shale in-situ heating simulation experiments is preventing the products of shale in-situ heating from clogging the hydrocarbon removal pipeline.

[0050] Given the drawbacks of the aforementioned simulation methods, the inventors of this application have attempted various solutions, such as improving the kerogen hydrocarbon generation simulation experiment and the hydrocarbon generation and expulsion simulation of dried shale samples to make them relevant to in-situ heated shale oil and gas development, but without achieving satisfactory results. Other attempts included improving the experimental equipment for the heating simulation experiment of undried original shale samples, changing experimental conditions, altering the material of the connecting pipes, and changing the pipe connection method, but these attempts failed to solve the problem of hydrocarbon expulsion pipe blockage. Through various attempts, the inventors of this application discovered that using at least two hydrocarbon expulsion pipes for switching and backup, and using the backup pipe when one hydrocarbon expulsion pipe is blocked, is effective. Each hydrocarbon expulsion route employs a two-section hydrocarbon expulsion pipe with a thicker inner section and a thinner outer section, ensuring that blockages generally occur at the thinner inlet of the hydrocarbon expulsion pipe. A three-way valve connects the inner and outer hydrocarbon expulsion pipes of different inner diameters, and the three-way valve allows the easily blocked thinner inner diameter outer hydrocarbon expulsion pipe to be disassembled. Timely cleaning and replacement of blocked pipes effectively solves the problem of hydrocarbon expulsion pipe blockage.

[0051] Example 1

[0052] Embodiment 1 of this invention provides a shale in-situ heating hydrocarbon removal pipeline anti-clogging device, which can be applied to the fields of shale oil and gas exploration and development and shale oil and gas resource evaluation. In particular, during the shale heating process, it ensures the success of in-situ heating simulation experiments on low-maturity shale, providing support for the selection of heating conditions during shale development through in-situ heating. Its structure is as follows: Figure 1 As shown, it includes:

[0053] At least two hydrocarbon discharge branches are connected to the reactor. Each hydrocarbon discharge branch includes an internal hydrocarbon discharge pipe and an external hydrocarbon discharge pipe connected by a branch control valve. The internal hydrocarbon discharge pipe can be fixedly installed on the reactor, and the external hydrocarbon discharge pipe can be detachably installed outside the reactor.

[0054] A main hydrocarbon discharge pipeline connecting at least two hydrocarbon discharge branches;

[0055] A first pressure detection unit is installed on the reactor to detect the pressure inside the reactor.

[0056] A second pressure detection unit is installed on the main hydrocarbon discharge pipeline to detect the pressure of the main hydrocarbon discharge pipeline;

[0057] In system operation, at least one branch control valve for hydrocarbon discharge is open, while the control valves for other hydrocarbon discharge branches are closed. If the difference between the pressure inside the reactor and the preset hydrocarbon discharge pressure threshold is greater than the set differential pressure threshold, and the total hydrocarbon discharge pipeline pressure is less than or equal to the hydrocarbon discharge pressure threshold, it is determined that the hydrocarbon discharge branch with its control valve open is blocked. At least one other hydrocarbon discharge branch is then selected to open its control valve for switching. The differential pressure threshold can be set as needed. A set differential pressure threshold can ensure that the pressure inside the reactor is significantly greater than the preset hydrocarbon discharge pressure threshold while the total hydrocarbon discharge pipeline pressure is less than or equal to the hydrocarbon discharge pressure threshold, thus confirming that the hydrocarbon discharge branch with its control valve open is blocked.

[0058] See the above-mentioned anti-clogging device for shale in-situ heating and hydrocarbon removal pipelines. Figure 1 The portion within the dashed box includes the hydrocarbon discharge pipeline unit and the hydrocarbon discharge pipeline blockage detection unit; the hydrocarbon discharge pipeline unit includes at least two hydrocarbon discharge branches. Figure 1 The example uses two hydrocarbon discharge branches. Each branch includes one internal hydrocarbon discharge pipe, one detachable external hydrocarbon discharge pipe, and several related control valves, such as... Figure 1 As shown, one hydrocarbon discharge branch includes an internal hydrocarbon discharge pipe 11 and an external hydrocarbon discharge pipe 12, and another hydrocarbon discharge branch includes an internal hydrocarbon discharge pipe 13 and an external hydrocarbon discharge pipe 14. The hydrocarbon discharge pipe blockage detection unit includes at least two high-precision pressure detection units, which can be pressure gauges. One pressure gauge 21 is connected to the reactor 41 and is used to detect the pressure inside the reactor during heating. The other pressure gauge 22 is located on the main hydrocarbon discharge pipe 10 before the hydrocarbon discharge control valve. When the hydrocarbon discharge pipe is not blocked, the pressure inside the reactor and the pressure in the hydrocarbon discharge pipe before the hydrocarbon discharge control valve remain consistent during the experiment (i.e., the readings of the two pressure gauges are equal). When the readings of the two pressure gauges are inconsistent, it indicates that the hydrocarbon discharge pipe is blocked. The accuracy class of the pressure gauges can be selected as needed, for example, the accuracy class can be 0.01 MPa. Pressure gauge 21 is connected to the reactor body, and pressure gauge 22 is connected to the main hydrocarbon discharge pipe. Sample 51 can be placed in the reactor 41.

[0059] During the experiment, at least one of the two hydrocarbon discharge branches must be opened, and at least one must remain closed. For example, with two hydrocarbon discharge branches, the first branch must be opened, and the second branch must be kept closed via a valve. During the experiment, if the pressure inside the reactor is the same as that on the main hydrocarbon discharge pipeline, the hydrocarbon discharge branch is unobstructed. If salts dissolved in the original shale formation water evaporate during shale heating and precipitate at the outlet of the hydrocarbon discharge pipeline, causing blockage, the pressure inside and outside the reactor will be inconsistent. If the pressure inside the reactor is inconsistent with that on the main hydrocarbon discharge pipeline, the first hydrocarbon discharge branch is blocked. At this point, the first blocked hydrocarbon discharge branch is closed, and the second hydrocarbon discharge branch is opened. Simultaneously, the external hydrocarbon discharge pipe of the blocked first branch is removed and cleaned. After the external hydrocarbon discharge pipe is cleared, it is reinstalled on the first hydrocarbon discharge branch. When the second hydrocarbon discharge branch also becomes blocked, the first hydrocarbon discharge branch can be reused. The first hydrocarbon discharge branch can be opened again, while the second hydrocarbon discharge branch is closed and then disassembled and cleared. This ensures that the hydrocarbon discharge system remains unobstructed during the in-situ heating simulation of low-mature shale.

[0060] In some optional embodiments, the inner diameter of the internal hydrocarbon discharge pipe is larger than the inner diameter of the external hydrocarbon discharge pipe, or the ratio of the inner diameter of the internal hydrocarbon discharge pipe to the inner diameter of the external hydrocarbon discharge pipe is greater than 2. For example, the inner diameter of the internal hydrocarbon discharge pipe is 8~10mm, and the inner diameter of the external hydrocarbon discharge pipe is 3~6mm. Correspondingly, the port diameter of the branch control valve connected to the internal hydrocarbon discharge pipe is larger, and the port diameter connected to the external hydrocarbon discharge pipe is smaller. A reducing three-way valve (e.g., three-way valve 31 and three-way valve 32 in the figure) is provided on the side wall of the reactor body. The internal hydrocarbon discharge pipe and the external hydrocarbon discharge pipe are connected through the three-way valve, and the screw rod on the three-way valve can control the connection and disconnection between the internal hydrocarbon discharge pipe and the external hydrocarbon discharge pipe.

[0061] In the aforementioned apparatus, the external hydrocarbon discharge pipe of each hydrocarbon discharge branch is detachable, and the connection and closure of the internal and external hydrocarbon discharge pipes are achieved through a three-way valve at the end of the internal hydrocarbon discharge pipe on each branch. Furthermore, when the external hydrocarbon discharge pipe is removed, the reactor body remains sealed from the outside environment. Preferably, the three-way valve connecting the internal and external hydrocarbon discharge pipes has a different orifice diameter, with one end having a larger diameter and the other a smaller diameter. The larger diameter end of the three-way valve is positioned close to the reactor wall, allowing for either sealing or opening between the reactor body and the external hydrocarbon discharge pipe.

[0062] In some optional embodiments, a solenoid valve 34 is provided on the main hydrocarbon discharge line, and a multi-way valve is provided between the main hydrocarbon discharge line and at least two hydrocarbon discharge branches, for example... Figure 1 The four-way valve 33 shown is shown.

[0063] In some optional embodiments, the above-described apparatus further includes:

[0064] A third pressure detection unit is installed on the external hydrocarbon discharge pipe of the hydrocarbon discharge branch to detect the pressure of the hydrocarbon discharge branch. This unit determines, based on the pressure of the hydrocarbon discharge branch, the pressure inside the reactor, and the pressure of the total hydrocarbon discharge pipeline, whether the hydrocarbon discharge branch with its control valve open is blocked and locates the blockage, and whether the hydrocarbon discharge branch with its control valve closed is in a cut-off state. See also Figure 1 As shown, each hydrocarbon discharge branch is equipped with a pressure gauge on its outgoing hydrocarbon discharge pipe to detect the pressure in the pipe. Pressure gauge 24 is installed on outgoing hydrocarbon discharge pipe 12, and pressure gauge 23 is installed on outgoing hydrocarbon discharge pipe 24.

[0065] For example, for a hydrocarbon discharge branch with its branch control valve open, if the pressure in the hydrocarbon discharge branch, the pressure inside the reactor, and the pressure in the main hydrocarbon discharge pipeline are all the same, the hydrocarbon discharge branch is considered unobstructed. If the pressure in the hydrocarbon discharge branch and the pressure in the main hydrocarbon discharge pipeline are the same, but the pressure inside the reactor is different, it indicates that the blockage is located in the third detection unit and on the inside, that is, in the section of the hydrocarbon discharge branch close to the reactor, such as at the connection between the inner and outer hydrocarbon discharge pipes. If the pressure in the hydrocarbon discharge branch and the pressure inside the reactor are the same, but the pressure in the main hydrocarbon discharge pipeline is different, it indicates that the blockage is located in the third detection unit and on the outside, that is, in the section of the hydrocarbon discharge branch close to the main hydrocarbon discharge pipeline, such as at the connection between the outer and main hydrocarbon discharge pipes.

[0066] For example, for a hydrocarbon discharge branch whose control valve is closed, if the pressure of the hydrocarbon discharge branch is the same as the pressure of the total hydrocarbon discharge pipeline, but the pressure inside the reactor is different, it is considered that the hydrocarbon discharge branch whose control valve is closed is in a cut-off state. If the pressure of the hydrocarbon discharge branch, the pressure inside the reactor, and the pressure of the total hydrocarbon discharge pipeline are all the same, it is considered that the hydrocarbon discharge branch whose control valve is closed has failed to effectively cut off the passage, which may be due to a failure of the control valve, and timely repair is required.

[0067] Example 2

[0068] Embodiment 2 of the present invention provides a shale in-situ heating system for preventing blockage of hydrocarbon discharge pipelines, comprising: a reaction vessel, a control device, and a shale in-situ heating hydrocarbon discharge pipeline anti-blockage device; its structure is described in detail below. Figure 1 As shown, the control device is not shown. The structure and function of the anti-clogging device for the shale in-situ heating and hydrocarbon discharge pipeline are described in Example 1.

[0069] The control device is used to acquire the pressure inside the reactor detected by the first pressure detection unit and the total hydrocarbon discharge pipeline pressure detected by the second pressure detection unit, and to determine whether the hydrocarbon discharge branch opened by the branch control valve is blocked based on the pressure inside the reactor, the total hydrocarbon discharge pipeline pressure and the preset hydrocarbon discharge pressure threshold.

[0070] In some optional embodiments, the control device described above is further used for:

[0071] The pressure of the hydrocarbon discharge branch detected by the third pressure detection unit on the external hydrocarbon discharge pipe of the control valve-opened hydrocarbon discharge branch is obtained. Based on the hydrocarbon discharge branch pressure, the pressure inside the reactor and the total hydrocarbon discharge pipeline pressure, it is determined whether the hydrocarbon discharge branch with the branch control valve open is blocked and the location of the blockage is located, and whether the hydrocarbon discharge branch with the control valve closed is in a cut-off state.

[0072] Example 3

[0073] Embodiment 3 of the present invention provides a method for preventing blockage of shale in-situ heating and hydrocarbon removal pipelines, which is implemented using the shale in-situ heating device for preventing blockage of hydrocarbon removal pipelines in Embodiment 1 or the shale in-situ heating system for preventing blockage of hydrocarbon removal pipelines in Embodiment 2. The method flow is as follows: Figure 2 As shown, it includes:

[0074] S101: Select at least one hydrocarbon discharge branch and open its branch control valve, while keeping the branch control valves of other hydrocarbon discharge branches closed.

[0075] Taking the setting of two hydrocarbon discharge branches as an example, during the experiment, one of the two hydrocarbon discharge branches is opened, while the other is kept closed by a valve.

[0076] S102: Real-time monitoring of the pressure inside the reactor detected by the first pressure detection unit and the total hydrocarbon discharge pipeline pressure detected by the second pressure detection unit.

[0077] During the experiment, the pressure inside the reactor was monitored in real time by the first pressure detection unit and the pressure of the total hydrocarbon discharge pipeline was monitored in real time by the second pressure detection unit.

[0078] S103: If the difference between the pressure inside the reactor and the preset hydrocarbon discharge pressure threshold is greater than the set differential pressure threshold, and the total hydrocarbon discharge pipeline pressure is less than or equal to the hydrocarbon discharge pressure threshold, it is determined that the hydrocarbon discharge branch with the branch control valve open is blocked.

[0079] When the pressure inside the reactor body is the same as that on the main hydrocarbon discharge pipeline, it indicates that the hydrocarbon discharge pipeline is unobstructed; when the pressure inside the reactor body is different from that on the main hydrocarbon discharge pipeline, it indicates that the hydrocarbon discharge pipeline is blocked.

[0080] S104: Select a branch control valve that is closed for hydrocarbon discharge, open the branch control valve, and close the branch control valve of the blocked hydrocarbon discharge branch. Then remove its external hydrocarbon discharge pipe, clear the blockage, and then reinstall it.

[0081] If it is determined that the hydrocarbon discharge branch controlled by the branch control valve is blocked, open another hydrocarbon discharge branch. Then close the blocked hydrocarbon discharge branch to seal and isolate the internal hydrocarbon discharge pipe from the outside. Remove the external hydrocarbon discharge pipe of the blocked hydrocarbon discharge branch, clean and unclog the removed blocked external hydrocarbon discharge pipe, and then reinstall the unclogged external hydrocarbon discharge pipe for reuse.

[0082] In some optional embodiments, the above method further includes:

[0083] The pressure of each hydrocarbon discharge branch is detected in real time by the third pressure detection unit on the external hydrocarbon discharge pipe of each branch; based on the pressure of the hydrocarbon discharge branch, the pressure inside the reactor and the pressure of the total hydrocarbon discharge pipeline, it is determined whether the hydrocarbon discharge branch with the branch control valve open is blocked and the location of the blockage is located, and it is determined whether the hydrocarbon discharge branch with the control valve closed is in the cut-off state.

[0084] Regarding the apparatus, system, and method in the above embodiments, the relevant content of one part has been described in detail in another part, and will not be elaborated in detail in that part.

[0085] See Figure 3 The figure shows real-time pressure curves of the reactor body and the hydrocarbon discharge pipeline recorded during the shale in-situ heating simulation experiment provided in this embodiment of the invention. The horizontal axis represents time, and the vertical axis represents pressure. Dark gray represents the pressure inside the reactor body, and light gray represents the pressure in the hydrocarbon discharge pipeline. The figure shows the pressure changes of the reactor body and the hydrocarbon discharge pipeline with reaction time during the shale heating simulation experiment, after the first hydrocarbon discharge branch is blocked and the second hydrocarbon discharge branch is opened. The hydrocarbon discharge pressure during the experiment was 2.5 MPa, and the residual pressure inside the reactor body after each hydrocarbon discharge was 2.0 MPa. (Refer to...) Figure 3 As shown, during the experiment, approximately 4000 minutes prior, the pressure changes inside the reactor and in the hydrocarbon discharge pipeline remained consistent, changing synchronously between 2.0 and 2.5 MPa. This indicated that the pressure inside the reactor and on the main hydrocarbon discharge pipeline were the same, suggesting that the hydrocarbon discharge pipeline was unobstructed. From approximately 4000 minutes to 5200 minutes, the pressure inside the reactor rose to 2.5-3 MPa, while the pressure in the hydrocarbon discharge pipeline remained at 2.5 MPa. This discrepancy between the pressure inside the reactor and on the main hydrocarbon discharge pipeline indicated that the hydrocarbon discharge pipeline was blocked. After opening the second hydrocarbon discharge branch, i.e., after 5200 minutes, the pressure changes inside the reactor and in the hydrocarbon discharge pipeline returned to being consistent, changing synchronously between 2.0 and 2.5 MPa.

[0086] The above-mentioned anti-clogging device, system, and method for shale in-situ heating hydrocarbon removal pipelines provided in the embodiments of the present invention include, but are not limited to, the following beneficial effects: it can easily detect whether the hydrocarbon removal pipeline is blocked during the in-situ heating experiment of low-mature shale, ensuring that at least one hydrocarbon removal pipeline is unobstructed during the entire experiment, so as to ensure the smooth progress of the experiment.

[0087] Unless otherwise specifically stated, terms such as processing, calculation, operation, determination, display, etc., may refer to the actions and / or processes of one or more processing or computing systems or similar devices that represent the manipulation and conversion of data representing physical (e.g., electronic) quantities within the registers or memory of the processing system into other data similarly representing physical quantities within the memory, registers, or other such information storage, transmission, or display devices of the processing system. Information and signals can be represented using any of a variety of different techniques and methods. For example, data, instructions, commands, information, signals, bits, symbols, and chips mentioned throughout the above description can be represented by voltage, current, electromagnetic waves, magnetic fields or particles, light fields or particles, or any combination thereof.

[0088] It should be understood that the specific order or hierarchy of steps in the disclosed process is an example of an exemplary method. Based on design preferences, it should be understood that the specific order or hierarchy of steps in the process may be rearranged without departing from the scope of this disclosure. The appended method claims provide elements of various steps in an exemplary order and are not intended to limit the scope to the specific order or hierarchy described.

[0089] In the detailed description above, various features are combined together in a single embodiment to simplify this disclosure. This approach to disclosure should not be construed as reflecting an intention that embodiments of the claimed subject matter require more features than those stated in each claim. Rather, as reflected in the appended claims, the invention is presented with fewer features than all of the features in a single disclosed embodiment. Therefore, the appended claims are hereby clearly incorporated into the detailed description, wherein each claim stands alone as a preferred embodiment of the invention.

[0090] Those skilled in the art will also understand that the various illustrative logic blocks, modules, circuits, and algorithm steps described in conjunction with the embodiments herein can be implemented as electronic hardware, computer software, or a combination thereof. To clearly illustrate the interchangeability between hardware and software, the various illustrative components, blocks, modules, circuits, and steps described above are generally described in terms of their functionality. Whether such functionality is implemented as hardware or software depends on the specific application and the design constraints imposed on the overall system. Those skilled in the art can implement the described functionality in alternative ways for each specific application; however, such implementation decisions should not be construed as departing from the scope of this disclosure.

[0091] The steps of the methods or algorithms described in conjunction with the embodiments herein can be directly embodied in hardware, software modules executed by a processor, or a combination thereof. The software modules can reside in RAM memory, flash memory, ROM memory, EPROM memory, EEPROM memory, registers, hard disks, removable disks, CD-ROMs, or any other form of storage medium well known in the art. An exemplary storage medium is connected to the processor, enabling the processor to read information from and write information to the storage medium. Of course, the storage medium can also be a component of the processor. The processor and storage medium can reside in an ASIC. The ASIC can reside in a user terminal. Alternatively, the processor and storage medium can exist as discrete components in the user terminal.

[0092] For software implementation, the techniques described in this application can be implemented using modules (e.g., procedures, functions, etc.) that perform the functions described in this application. This software code can be stored in memory units and executed by a processor. The memory units can be implemented within the processor or outside the processor; in the latter case, they are communicatively coupled to the processor via various means, as is well known in the art.

[0093] The foregoing description includes examples of one or more embodiments. It is certainly impossible to describe all possible combinations of components or methods in order to describe the above embodiments, but those skilled in the art will recognize that further combinations and arrangements of the various embodiments are possible. Therefore, the embodiments described herein are intended to cover all such changes, modifications, and variations that fall within the scope of the appended claims. Furthermore, the term “comprising” as used in the specification or claims is interpreted in a manner similar to the term “including,” as it is understood when used as a conjunction in the claims. Additionally, the use of any term “or” in the specification of the claims is intended to mean “non-exclusive or.” The terms “first,” “second,” and “third” are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

Claims

1. A device for preventing blockage in shale in-situ heating and hydrocarbon removal pipelines, characterized in that, include: At least two hydrocarbon discharge branches are connected to the reactor. Each hydrocarbon discharge branch includes an internal hydrocarbon discharge pipe and an external hydrocarbon discharge pipe connected by a branch control valve. The internal hydrocarbon discharge pipe is fixedly installed on the reactor, and the external hydrocarbon discharge pipe is detachably installed outside the reactor. The inner diameter of the internal hydrocarbon discharge pipe is larger than the inner diameter of the external hydrocarbon discharge pipe, or the ratio of the inner diameter of the internal hydrocarbon discharge pipe to the inner diameter of the external hydrocarbon discharge pipe is greater than 2. The branch control valve has a larger diameter at the end connected to the internal hydrocarbon discharge pipe and a smaller diameter at the end connected to the external hydrocarbon discharge pipe. The internal hydrocarbon discharge pipe... The inner diameter of the inner hydrocarbon discharge pipe is 8~10mm, and the inner diameter of the outer hydrocarbon discharge pipe is 3~6mm. The inner hydrocarbon discharge pipe and the outer hydrocarbon discharge pipe are connected by a reducing three-way valve set on the side wall of the reactor body. The spiral rod on the three-way valve can control the connection and disconnection between the inner hydrocarbon discharge pipe and the outer hydrocarbon discharge pipe. A two-section hydrocarbon discharge pipe with a thicker inner diameter and a thinner outer diameter is used on each hydrocarbon discharge branch to ensure that blockage generally occurs at the inlet of the thinner pipe where the hydrocarbon discharge pipe becomes thinner. The outer hydrocarbon discharge pipe with a thinner inner diameter that is prone to blockage can be disassembled through the three-way valve. A main hydrocarbon discharge pipeline connecting at least two hydrocarbon discharge branches; A first pressure detection unit for detecting the pressure inside the reactor is installed on the reactor. A second pressure detection unit is installed on the main hydrocarbon discharge pipeline to detect the pressure of the main hydrocarbon discharge pipeline; In operation, at least one branch control valve of the hydrocarbon discharge branch is open, and the branch control valves of other hydrocarbon discharge branches are closed. If the difference between the pressure inside the reactor and the preset hydrocarbon discharge pressure threshold is greater than the set differential pressure threshold, and the total hydrocarbon discharge pipeline pressure is less than or equal to the hydrocarbon discharge pressure threshold, it is determined that the hydrocarbon discharge branch with the open branch control valve is blocked, and at least one other hydrocarbon discharge branch is selected to open the branch control valve for switching. The device also includes a third pressure detection unit installed on the external hydrocarbon discharge pipe of the hydrocarbon discharge branch for detecting the pressure of the hydrocarbon discharge branch, so as to determine whether the hydrocarbon discharge branch with the branch control valve open is blocked and locate the location of the blockage, and determine whether the hydrocarbon discharge branch with the control valve closed is in a cut-off state, based on the pressure of the hydrocarbon discharge branch, the pressure inside the reactor and the pressure of the total hydrocarbon discharge pipeline.

2. The apparatus as claimed in claim 1, characterized in that, The main hydrocarbon discharge pipeline is equipped with a solenoid valve, and a multi-way valve is provided between the main hydrocarbon discharge pipeline and at least two hydrocarbon discharge branches.

3. A shale in-situ heating system for preventing blockage of hydrocarbon discharge pipelines, characterized in that, include: The reaction vessel, the control device, and the anti-clogging device for the shale in-situ heating and hydrocarbon removal pipeline as described in any one of claims 1-2; The control device is used to acquire the pressure inside the reactor detected by the first pressure detection unit and the total hydrocarbon discharge pipeline pressure detected by the second pressure detection unit, and to determine whether the hydrocarbon discharge branch opened by the branch control valve is blocked based on the pressure inside the reactor, the total hydrocarbon discharge pipeline pressure and the preset hydrocarbon discharge pressure threshold.

4. The system as described in claim 3, characterized in that, The control device is also used for: The pressure of the hydrocarbon discharge branch detected by the third pressure detection unit on the external hydrocarbon discharge pipe of the control valve-opened hydrocarbon discharge branch is obtained. Based on the hydrocarbon discharge branch pressure, the pressure inside the reactor and the total hydrocarbon discharge pipeline pressure, it is determined whether the hydrocarbon discharge branch with the control valve open is blocked and the location of the blockage is located, and it is determined whether the hydrocarbon discharge branch with the control valve closed is in a cut-off state.

5. A method for preventing blockage in shale in-situ heating and hydrocarbon removal pipelines, characterized in that, This is achieved using a shale in-situ heating system for preventing blockage of hydrocarbon discharge pipelines as described in any one of claims 3-4.

6. The method as described in claim 5, characterized in that, include: Select at least one hydrocarbon discharge branch and open its branch control valve, while keeping the branch control valves of the other hydrocarbon discharge branches closed; The pressure inside the reactor detected by the first pressure detection unit and the pressure in the total hydrocarbon discharge pipeline detected by the second pressure detection unit are monitored in real time. If the difference between the pressure inside the reactor and the preset hydrocarbon discharge pressure threshold is greater than the set differential pressure threshold, and the pressure in the total hydrocarbon discharge pipeline is less than or equal to the hydrocarbon discharge pressure threshold, it is determined that the hydrocarbon discharge branch opened by the branch control valve is blocked. Select a branch control valve that is closed for hydrocarbon discharge, open the branch control valve, and close the branch control valve of the blocked hydrocarbon discharge branch. Then remove its external hydrocarbon discharge pipe, clear the blockage, and reinstall it.

7. The method as described in claim 5 or 6, characterized in that, Also includes: Real-time monitoring of the hydrocarbon discharge branch pressure detected by the third pressure detection unit on the hydrocarbon discharge pipe of each hydrocarbon discharge branch; Based on the pressure of the hydrocarbon discharge branch, the pressure inside the reactor, and the pressure of the total hydrocarbon discharge pipeline, it is determined whether the hydrocarbon discharge branch with the branch control valve open is blocked and the location of the blockage is located, and it is determined whether the hydrocarbon discharge branch with the control valve closed is in a cut-off state.

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