Anti-blocking method and device for shale in-situ heating hydrocarbon discharge pipeline and related system

Abstract

The invention discloses an anti-blocking method and device for a shale in-situ heating hydrocarbon discharge pipeline and a related system. The device comprises at least two hydrocarbon discharge branches connected with a reaction kettle, each hydrocarbon discharge branch comprises a branch control valve, an inner hydrocarbon discharge pipe and an outer hydrocarbon discharge pipe, the inner hydrocarbon discharge pipe can be fixedly installed on the reaction kettle, and the outer hydrocarbon discharge pipe is detachably installed outside the reaction kettle; the total hydrocarbon expulsion pipeline is connected with the at least two hydrocarbon expulsion branches; the first pressure detection unit is used for detecting the pressure in the reaction kettle; the second pressure detection unit is used for detecting the pressure of the total hydrocarbon discharge pipeline; in the working state of the system, 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 of the total hydrocarbon discharge pipeline and the hydrocarbon discharge pressure set by the total hydrocarbon discharge pipeline, at least one other hydrocarbon discharge branch is selected to open the branch control valve for switching. It can be guaranteed that the hydrocarbon discharging pipeline is in a smooth state all the time in the shale in-situ heating process, and experiment failures and experiment safety accidents are avoided.

Description

Technical Field

[0001] The present invention relates to the technical field of shale oil and gas exploration and development, and in particular to a shale in-situ heating hydrocarbon expulsion pipeline anti-clogging method, device and related system. Background Art

[0002] Shale oil is one of the main growth points of oil production at present. The organic-rich shales developed in China can be generally divided into two categories: the ancient marine shale formations in the south and the Mesozoic and Cenozoic terrestrial shale formations in the north. The ancient marine shale formations in the south are highly mature (Ro>2.0%) and are the main shale gas producing areas in my country. The shales widely developed in the north are mostly in the medium-low maturity stage, except for the limited areas of individual basins with a maturity greater than 1.3%. Due to the relatively low maturity, small amount of organic matter oil generation, high content of heavy components, high specific gravity, high viscosity and low gas-oil ratio of the generated crude oil, it is not suitable for direct mining, and is more suitable for shale oil and gas development through in-situ heating. Whether a specific set of low-maturity shales has the value of shale oil development, the determination of the optimal temperature and pressure conditions for in-situ heating development of shale oil, etc. need to be demonstrated through pilot simulation experiments. The optimal temperature and pressure conditions in the process of in-situ heating and mining of shale are determined through simulation experiments, providing a reference for the efficient development of shale oil and gas by in-situ heating. Summary of the invention

[0003] In order to reduce the adsorption of crude oil in the hydrocarbon drainage pipeline during the shale in-situ heating simulation experiment, the hydrocarbon drainage pipeline is generally thinner when the simulation equipment is designed and manufactured. During the experiment, the hydrocarbon drainage pipeline is often blocked. However, shale in-situ heating is the heating process of the original rock sample. The original rock sample contains a certain amount of water, and these waters will dissolve certain salts, especially carbonates. During the heating of the shale sample, these dissolved salts will slowly evaporate with the water vapor and will precipitate in the hydrocarbon drainage pipeline at a lower temperature, just like the scale in a kettle, causing the hydrocarbon drainage pipe to be blocked, resulting in the failure of the entire in-situ heating experiment, and even leading to experimental safety accidents. Therefore, how to effectively prevent the shale in-situ heating products from clogging the hydrocarbon drainage pipeline during the shale in-situ heating simulation experiment has become a technical problem that needs to be solved urgently.

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

[0005] The embodiment of the present invention provides a shale in-situ heating hydrocarbon expulsion pipeline anti-blocking device, comprising:

[0006] At least two hydrocarbon exhaust branches connected to the reactor, the hydrocarbon exhaust branches comprising an inner hydrocarbon exhaust pipe and an outer hydrocarbon exhaust pipe connected via a branch control valve, the inner hydrocarbon exhaust pipe being fixedly mounted on the reactor, and the outer hydrocarbon exhaust pipe being detachably mounted outside the reactor;

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

[0008] A first pressure detection unit is provided on the reactor for detecting the pressure inside the reactor;

[0009] A second pressure detection unit disposed on the total hydrocarbon exhaust pipeline for detecting the pressure of the total hydrocarbon exhaust pipeline;

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

[0011] In some optional embodiments, the inner diameter of the inner hydrocarbon exhaust pipe is larger than the inner diameter of the outer hydrocarbon exhaust pipe, or the ratio of the inner diameter of the inner hydrocarbon exhaust pipe to the inner diameter of the outer hydrocarbon exhaust pipe is greater than 2; the port of the branch control valve connected to the inner hydrocarbon exhaust pipe has a larger diameter, and the port connected to the outer hydrocarbon exhaust pipe has a smaller diameter.

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

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

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

[0015] A third pressure detection unit is arranged on the external hydrocarbon exhaust pipe of the hydrocarbon exhaust branch for detecting the pressure of the hydrocarbon exhaust branch, so as to determine whether the hydrocarbon exhaust branch with the branch control valve opened is blocked and locate the blockage position based on the hydrocarbon exhaust branch pressure, the pressure in the reactor and the total hydrocarbon exhaust pipeline pressure, and determine whether the hydrocarbon exhaust branch with the control valve closed is in a cut-off state.

[0016] In some optional embodiments, a variable diameter three-way valve is provided on the side wall of the reactor body, the inner hydrocarbon exhaust pipe and the outer hydrocarbon exhaust pipe are connected via the three-way valve, and the spiral rod on the three-way valve can control the connection and disconnection between the inner hydrocarbon exhaust pipe and the outer hydrocarbon exhaust pipe.

[0017] The embodiment of the present invention provides a shale in-situ heating system for preventing hydrocarbon expulsion pipeline from being blocked, characterized in that it comprises: a reaction kettle, a control device, and a shale in-situ heating hydrocarbon expulsion pipeline anti-blocking device as claimed in any one of claims 1 to 6;

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

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

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

[0021] An embodiment of the present invention provides a method for preventing blockage of a shale in-situ heating hydrocarbon exhaust pipeline, characterized in that it is implemented using a shale in-situ heating system for preventing blockage of a hydrocarbon exhaust pipeline as described in any one of claims 7-8.

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

[0023] Select at least one hydrocarbon exhaust branch to open the branch control valve, and keep the branch control valves of other hydrocarbon exhaust branches closed;

[0024] Real-time monitoring of the pressure in the reactor detected by the first pressure detection unit and the total hydrocarbon exhaust pipeline pressure detected by the second pressure detection unit, if the difference between the pressure in the reactor and a preset hydrocarbon exhaust pressure threshold is greater than the set pressure difference threshold, and the total hydrocarbon exhaust pipeline pressure is less than or equal to the hydrocarbon exhaust pressure threshold, it is determined that the hydrocarbon exhaust branch opened by the branch control valve is blocked;

[0025] Select a hydrocarbon exhaust branch with a branch control valve closed, open the branch control valve, close the branch control valve of the blocked hydrocarbon exhaust branch, remove its external hydrocarbon exhaust pipe, dredge it, and then install it again.

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

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

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

[0029] The beneficial effects of the above technical solution provided by the embodiment of the present invention include at least:

[0030] The shale in-situ heating hydrocarbon exhaust pipeline anti-blocking device and blockage detection system provided in the embodiment of the present invention realizes the backup of the hydrocarbon exhaust branch by setting at least two parallel hydrocarbon exhaust branches. In actual application, the branch control valve of at least one of the hydrocarbon exhaust branches is opened to connect the hydrocarbon exhaust branch, and the branch control valves of other hydrocarbon exhaust branches are closed as backup. By detecting the pressure in the reactor and the pressure of the hydrocarbon exhaust pipeline, it is determined whether the hydrocarbon exhaust branch is blocked. When the connected hydrocarbon exhaust branch is blocked, the branch control valve of the hydrocarbon exhaust branch is closed, and the branch control valve of the backup hydrocarbon exhaust branch is opened to realize the switching of the hydrocarbon exhaust branch, thereby ensuring the unobstructed hydrocarbon exhaust pipeline and the normal progress of the experiment. The external hydrocarbon exhaust pipe of the blocked hydrocarbon exhaust branch can be disassembled for cleaning and replacement so that it can be switched later, thereby ensuring that the hydrocarbon exhaust pipeline can always be in a normal state, avoiding experimental failure and experimental safety accidents.

[0031] Other features and advantages of the present invention will be described in the following description, and partly become apparent from the description, or understood by practicing the present invention. The purpose and other advantages of the present invention can be realized and obtained by the structures particularly pointed out in the written description, claims, and drawings.

[0032] The technical solution of the present invention is further described in detail below through the accompanying drawings and embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] The accompanying drawings are used to provide a further understanding of the present invention and constitute a part of the specification. Together with the embodiments of the present invention, they are used to explain the present invention and do not constitute a limitation of the present invention. In the accompanying drawings:

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

[0035] Figure 2 This is a flow chart of a method for preventing clogging of a shale in-situ heating hydrocarbon expulsion pipeline in an embodiment of the present invention;

[0036] Figure 3 It is a real-time curve of the pressure in the reactor and the pressure in the hydrocarbon exhaust pipeline recorded in the shale in-situ heating simulation experiment in the embodiment of the present invention. DETAILED DESCRIPTION

[0037] The exemplary embodiments of the present disclosure will be described in more detail below with reference to the accompanying drawings. Although the exemplary embodiments of the present disclosure are shown in the accompanying drawings, it should be understood that the present disclosure can be implemented in various forms and should not be limited by the embodiments set forth herein. On the contrary, these embodiments are provided to enable a more thorough understanding of the present disclosure and to fully convey the scope of the present disclosure to those skilled in the art.

[0038] It should be understood that the terms described in the present invention are only for describing special embodiments and are not intended to limit the present invention. In addition, for the numerical range in the present invention, it should be understood that each intermediate value between the upper and lower limits of the scope is also specifically disclosed. Each smaller range between the intermediate value in any stated value or stated range and any other stated value or intermediate value in the described range is also included in the present invention. The upper and lower limits of these smaller ranges can be independently included or excluded in the scope.

[0039] Unless otherwise indicated, all technical and scientific terms used herein have the same meanings as commonly understood by those skilled in the art to which the invention belongs. Although the present invention describes only preferred methods and materials, any methods and materials similar or equivalent to those described herein may also be used in the implementation or testing of the present invention. All documents mentioned in this specification are incorporated by reference to disclose and describe the methods and / or materials related to the documents. In the event of a conflict with any incorporated document, the content of this specification shall prevail.

[0040] In the description of the present invention, it should be noted that the terms "include", "comprising", "having", "containing", etc. are all open terms, that is, they mean including but not limited to. In addition, the terms "first", "second", etc. are only used for descriptive purposes and cannot be understood as indicating or implying relative importance.

[0041] Simulation experiment is the most important method to evaluate the oil and gas production potential of in-situ heating of medium and low maturity shale. The inventors found that the current simulation experiment methods for evaluating the oil and gas production potential of in-situ heating of medium and low maturity shale can be roughly divided into two categories according to sample characteristics and experimental methods:

[0042] (I) Kerogen hydrocarbon generation simulation experiment method

[0043] This experimental method mostly uses the results of hydrocarbon generation simulation experiments of kerogen in a closed system of a gold tube to infer the oil and gas production during the in-situ heating process of shale. However, during the in-situ heating process of this experimental method, the oil and gas generated by organic matter in the shale cannot be fully developed, and a large part (heavy components) remains in the shale and cannot be developed. Since the amount of oil and gas generated by shale and the amount of oil and gas that can be developed are two completely different concepts, the kerogen hydrocarbon generation simulation experiment can only simulate how much oil and gas is generated during the in-situ heating of shale, but how much oil and gas generated by shale during in-situ heating can be produced, what is the composition of the oil and gas that can be produced, and at what temperature the maximum amount of oil and gas is produced are problems that cannot be solved by hydrocarbon generation simulation experiments. Therefore, the results of hydrocarbon generation simulation experiments have little reference significance for the evaluation of the oil and gas production potential of shale in-situ heating, the selection of the optimal heating rate, the optimal heating temperature and pressure.

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

[0045] This experimental method is mostly carried out on a hydrocarbon generation and expulsion simulation experimental device, based on the oil and gas production data of shale samples under certain static rock pressure and hydrocarbon expulsion pressure conditions during the heating process to evaluate the potential of shale in-situ heating to develop shale oil and gas. This experimental method can be divided into the following two categories according to the characteristics of shale samples:

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

[0047] The simulated experimental samples were subjected to low-temperature drying treatment before the experiment, so that the water in the original shale samples was completely evaporated. However, this resulted in a relatively large difference between the indoor experimental samples and the samples at the oil field site. In the on-site in-situ heating simulation experiment, the shale contained a certain amount of water. For example: the heating temperature range of in-situ heating of shale to develop shale oil and gas is 250-450℃. The presence of formation water will affect the hydrocarbon generation capacity of shale, and will also affect the hydrocarbon production (hydrocarbon expulsion) efficiency of shale. It is mainly manifested in the following aspects: ① A large number of simulation experiments have proved that water will react with organic matter in shale under relatively high temperature conditions (>300℃) to produce a large amount of CO2, while reducing the hydrocarbon generation capacity of organic matter; ② The water in the original shale contains a variety of metal ions, and these metal ions (such as, Mg 2+ ) has a significant impact on the generation of oil and gas and the cracking of crude oil (such as TSR), thereby affecting the oil and gas production temperature, oil and gas production and properties of shale in situ heating. ③ The water in the original shale is easily vaporized during the in situ heating process, which increases the pressure in the experimental system, thereby affecting the oil and gas production during the in situ heating of shale. For the above reasons, the reference value of the experimental results using dried shale samples in the in situ heating development of shale oil and gas is significantly reduced.

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

[0049] Undried original shale samples are closer to the original characteristics of shale underground, so the indoor heating simulation experimental data of undried original shale samples are more meaningful for the development of shale oil and gas through in-situ heating. However, the original shale under formation conditions contains a certain amount of formation water, and there are certain salts (especially carbonates) in these waters. During the heating process of rock samples, these dissolved salts will slowly evaporate with water vapor and precipitate in the low-temperature hydrocarbon drainage pipeline (like scale), which generally causes small-caliber external hydrocarbon drainage to be blocked, and the hydrocarbon drainage process cannot proceed smoothly, resulting in the failure of the entire in-situ heating experiment, and even causing experimental safety accidents. Therefore, one of the main problems that need to be solved in the shale in-situ heating simulation experiment is to prevent the shale in-situ heating products from clogging the hydrocarbon drainage pipeline.

[0050] In view of the drawbacks of the above-mentioned various simulation test methods, the inventors of the present application have tried various solutions, such as: trying to improve the kerogen hydrocarbon generation simulation test method and the hydrocarbon generation and expulsion simulation of dried shale samples, so as to make them have reference significance for shale in-situ heating oil and gas development, but no better improvement effect has been achieved. For example: improving the experimental equipment of the heating simulation experiment of the original undried shale sample, changing the experimental conditions, changing the material of the connecting pipeline diameter, the connection method of the pipeline, etc., but these attempts have failed to solve the problem of hydrocarbon discharge pipeline blockage. After various attempts, the inventors of the present application found that at least two hydrocarbon discharge pipelines are used to switch between each other as spares, and when one hydrocarbon discharge pipeline is blocked, the spare pipeline is used. A two-stage hydrocarbon discharge pipeline with a thick inner and a thin outer section is used on each hydrocarbon discharge route to ensure that blockage generally occurs at the entrance of the thin pipe from the thicker to the thinner pipe of the hydrocarbon discharge pipeline, and the inner and outer hydrocarbon discharge pipes with different inner diameters are connected by a three-way valve, and it is ensured that the outer hydrocarbon discharge pipe with a thin inner diameter that is easy to be blocked can be disassembled by the three-way valve, and timely cleaning and replacement of the blocked pipeline can effectively solve the problem of hydrocarbon discharge pipeline blockage.

[0051] Embodiment 1

[0052] The first embodiment of the present invention provides a shale in-situ heating hydrocarbon discharge pipeline anti-blocking device, which can be applied to the shale oil and gas exploration and development and shale oil and gas resource evaluation technology fields, especially in the shale heating process, to ensure the success of the low-maturity shale in-situ heating simulation experiment, and provide support for the selection of heating conditions in the shale development process through in-situ heating. Figure 1 As shown, including:

[0053] At least two hydrocarbon exhaust branches connected to the reactor, the hydrocarbon exhaust branches comprising an inner hydrocarbon exhaust pipe and an outer hydrocarbon exhaust pipe connected through a branch control valve, the inner hydrocarbon exhaust pipe can be fixedly installed on the reactor, and the outer hydrocarbon exhaust pipe can be detachably installed outside the reactor;

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

[0055] A first pressure detection unit is provided on the reactor for detecting the pressure inside the reactor;

[0056] A second pressure detection unit disposed on the total hydrocarbon exhaust pipeline for detecting the pressure of the total hydrocarbon exhaust pipeline;

[0057] When the system is in working state, at least one branch control valve of the hydrocarbon exhaust branch is opened, and the branch control valves of other hydrocarbon exhaust branches are closed. If the difference between the pressure in the reactor and the preset hydrocarbon exhaust pressure threshold is greater than the set pressure difference threshold, and the total hydrocarbon exhaust pipeline pressure is less than or equal to the hydrocarbon exhaust pressure threshold, it is determined that the hydrocarbon exhaust branch with the branch control valve opened is blocked, and at least one other hydrocarbon exhaust branch is selected to open the branch control valve for switching. The pressure difference threshold can be set as needed. The set pressure difference threshold can make the pressure in the reactor much greater than the preset hydrocarbon exhaust pressure threshold and the total hydrocarbon exhaust pipeline pressure is less than or equal to the hydrocarbon exhaust pressure threshold, and it can be determined that the hydrocarbon exhaust branch with the branch control valve opened is blocked.

[0058] The above-mentioned shale in-situ heating hydrocarbon discharge pipeline anti-blocking device can be found in Figure 1 The portion within the dotted line frame includes a hydrocarbon exhaust pipeline unit and a hydrocarbon exhaust pipeline blockage detection unit; the hydrocarbon exhaust pipeline unit includes at least two hydrocarbon exhaust branches, Figure 1 In the figure, two hydrocarbon exhaust branches are taken as an example. Each hydrocarbon exhaust branch includes an inner hydrocarbon exhaust pipe, a detachable outer hydrocarbon exhaust pipe and multiple related control valves, such as Figure 1 As shown in , one hydrocarbon exhaust branch includes an inner hydrocarbon exhaust pipe 1 and an outer hydrocarbon exhaust pipe 1, and the other hydrocarbon exhaust branch includes an inner hydrocarbon exhaust pipe 2 and an outer hydrocarbon exhaust pipe 2. The hydrocarbon exhaust pipeline blockage detection unit includes at least two high-precision pressure detection units, and the pressure detection unit can be a pressure gauge, one of which is connected to the reactor and is used to detect the pressure in the reactor during the heating process. The other pressure gauge is located on the total hydrocarbon exhaust pipeline before the hydrocarbon exhaust control valve. When the hydrocarbon exhaust pipeline is not blocked, the pressure in the reactor body and the pressure in the hydrocarbon exhaust pipeline before the hydrocarbon exhaust control valve are always consistent during the experiment (that is, the readings of the two pressure gauges are equal). When the readings of the two pressure gauges are inconsistent, it means that the hydrocarbon exhaust pipeline is blocked. The accuracy level of the pressure gauge can be selected as needed, for example, the accuracy level can be 0.01 MPa. Pressure gauge 1 is connected to the reactor body, and pressure gauge 2 is connected to the total hydrocarbon exhaust pipeline.

[0059] During the experiment, at least one of the at least two hydrocarbon discharge branches is opened, and at least one is kept in an unopened state. Taking the setting of two hydrocarbon discharge branches as an example, the first hydrocarbon discharge branch is opened, and the second is kept in an unopened state through valve control. During the experiment, when the pressure inside the reactor body is consistent with that on the total hydrocarbon discharge pipeline, it means that the hydrocarbon discharge branch is unobstructed; when the salts dissolved in the original formation water of the shale are precipitated at the outlet of the external hydrocarbon discharge pipe as the water evaporates during the shale heating process, causing the hydrocarbon discharge pipeline to be blocked, it will cause the pressure inside and outside the reactor to be inconsistent. When the pressure inside the reactor body is inconsistent with that on the total hydrocarbon discharge pipeline, it means that the first hydrocarbon discharge branch is blocked. At this time, the blocked first hydrocarbon discharge branch is closed, the second hydrocarbon discharge branch is opened, and the external hydrocarbon discharge pipe of the blocked first hydrocarbon discharge branch is removed for dredging and cleaning. After the blocked external hydrocarbon discharge pipe is dredged, it is installed back to the first hydrocarbon discharge branch; when the second hydrocarbon discharge branch is also blocked, the first hydrocarbon discharge pipe can be reused, the first hydrocarbon discharge branch can be opened again, and the second hydrocarbon discharge branch is closed, and the second hydrocarbon discharge branch is dismantled and dredged. In this way, the hydrocarbon discharge system can be kept unblocked during the low-maturity shale in-situ heating simulation.

[0060] In some optional embodiments, the inner diameter of the inner hydrocarbon pipe is larger than the inner diameter of the outer hydrocarbon pipe, or the ratio of the inner diameter of the inner hydrocarbon pipe to the inner diameter of the outer hydrocarbon pipe is greater than 2. For example, the inner diameter of the inner hydrocarbon pipe is 8-10 mm, and the inner diameter of the outer hydrocarbon pipe is 3-6 mm. Correspondingly, the diameter of the end of the branch control valve connected to the inner hydrocarbon pipe is large, and the diameter of the end connected to the outer hydrocarbon pipe is small. A variable diameter three-way valve is arranged on the side wall of the reactor body, and the inner hydrocarbon pipe and the outer hydrocarbon pipe are connected through the three-way valve. The spiral rod on the three-way valve can control the connection and disconnection between the inner hydrocarbon pipe and the outer hydrocarbon pipe.

[0061] In the above device, the outer hydrocarbon discharge pipe of each hydrocarbon discharge branch is detachable, and the inner hydrocarbon discharge pipe and the outer hydrocarbon discharge pipe are connected and closed by the three-way valve at the end of the inner hydrocarbon discharge pipe on each hydrocarbon discharge branch, and when the outer hydrocarbon discharge pipe is removed, the reactor body is kept closed from the outside. Preferably, the three-way valve connecting the inner hydrocarbon discharge pipe and the outer hydrocarbon discharge pipe is a valve with a large diameter at one end and a small diameter at the other end, and the end with a large diameter is close to the reactor wall, and the end with a large diameter of the three-way valve can achieve sealing or opening between the reactor body and the outside of the hydrocarbon discharge pipe.

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

[0063] In some optional embodiments, the above device further includes:

[0064] A third pressure detection unit is provided on the outer hydrocarbon exhaust pipe of the hydrocarbon exhaust branch for detecting the pressure of the hydrocarbon exhaust branch, so as to determine whether the hydrocarbon exhaust branch with the branch control valve opened is blocked and locate the blockage position based on the hydrocarbon exhaust branch pressure, the pressure in the reactor and the total hydrocarbon exhaust pipeline pressure, and to determine whether the hydrocarbon exhaust branch with the control valve closed is in a cut-off state. Figure 1 As shown, each hydrocarbon exhaust pipe of each hydrocarbon exhaust branch is provided with a pressure gauge to detect the pressure in the hydrocarbon exhaust pipe. The hydrocarbon exhaust pipe 1 is provided with a pressure gauge 4, and the hydrocarbon exhaust pipe 2 is provided with a pressure gauge 3.

[0065] For example, for the hydrocarbon exhaust branch with the branch control valve opened, when the hydrocarbon exhaust branch pressure, the pressure in the reactor and the total hydrocarbon exhaust pipeline pressure are all the same, it is considered that the hydrocarbon exhaust branch is unobstructed; if the hydrocarbon exhaust branch pressure and the total hydrocarbon exhaust pipeline pressure are the same, but the pressure in the reactor is different, it means that the blockage position is between the third detection unit and the inner side, that is, a section of the hydrocarbon exhaust branch close to the reactor, such as the connection between the inner hydrocarbon exhaust pipe and the outer hydrocarbon exhaust pipe; if the hydrocarbon exhaust branch pressure and the pressure in the reactor are the same, but the total hydrocarbon exhaust pipeline pressure is different, it means that the blockage position is between the third detection unit and the outer side, that is, a section of the hydrocarbon exhaust branch close to the total hydrocarbon exhaust pipeline, such as the connection between the outer hydrocarbon exhaust pipe and the total hydrocarbon exhaust pipeline.

[0066] For example, for the hydrocarbon exhaust branch disconnected by the branch control valve, if the hydrocarbon exhaust branch pressure is the same as the total hydrocarbon exhaust pipeline pressure, but the pressure inside the reactor is different, it is considered that the hydrocarbon exhaust branch with the control valve closed is in a cut-off state; when the hydrocarbon exhaust branch pressure, the pressure inside the reactor and the total hydrocarbon exhaust pipeline pressure are all consistent, it is considered that the hydrocarbon exhaust branch closed by the control valve has failed to effectively cut off the passage, which may be due to the failure of the control valve and requires timely maintenance.

[0067] Embodiment 2

[0068] Embodiment 2 of the present invention provides a shale in-situ heating system for preventing hydrocarbon discharge pipeline from being blocked, comprising: a reactor, a control device and a shale in-situ heating hydrocarbon discharge pipeline anti-blocking device; Figure 1 As shown, the control device is not shown, and the structure and function of the shale in-situ heating hydrocarbon discharge pipeline anti-blocking device refer to the description of Example 1.

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

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

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

[0072] Embodiment 3

[0073] The third embodiment of the present invention provides a method for preventing clogging of a shale in-situ heating hydrocarbon expulsion pipeline, which is implemented by using the shale in-situ heating device for preventing clogging of a hydrocarbon expulsion pipeline of the first embodiment or the shale in-situ heating system for preventing clogging of a hydrocarbon expulsion pipeline of the second embodiment. The method flow is as follows: Figure 2 As shown, including:

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

[0075] Taking the setting of two hydrocarbon exhaust branches as an example, during the experiment, one of the two hydrocarbon exhaust branches was opened, and the other was kept closed through valve control.

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

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

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

[0079] When the pressure inside the reactor body is consistent with the pressure on the total hydrocarbon exhaust pipeline, it means that the hydrocarbon exhaust pipeline is unobstructed; when the pressure inside the reactor body is inconsistent with the pressure on the total hydrocarbon exhaust pipeline, it means that the hydrocarbon exhaust pipeline is blocked.

[0080] S104: Select a hydrocarbon exhaust branch whose branch control valve is closed, open the branch control valve, close the branch control valve of the blocked hydrocarbon exhaust branch, remove its external hydrocarbon exhaust pipe, dredge it, and then install it again.

[0081] If it is determined that the hydrocarbon exhaust branch opened by the branch control valve is blocked, open another hydrocarbon exhaust branch. Close the blocked hydrocarbon exhaust branch, seal and isolate the inner hydrocarbon exhaust pipe from the outside, remove the outer hydrocarbon exhaust pipe of the blocked hydrocarbon exhaust branch, clean and dredge the removed blocked outer hydrocarbon exhaust pipe, and then install the unblocked outer hydrocarbon exhaust pipe back for reuse.

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

[0083] Monitor the hydrocarbon exhaust branch pressure detected by the third pressure detection unit on the external hydrocarbon exhaust pipe of each hydrocarbon exhaust branch in real time; determine whether the hydrocarbon exhaust branch with the branch control valve open is blocked and locate the blockage position based on the hydrocarbon exhaust branch pressure, the pressure inside the reactor and the total hydrocarbon exhaust pipeline pressure, and determine whether the hydrocarbon exhaust branch with the control valve closed is in a cut-off state.

[0084] Regarding the devices, systems and methods in the above embodiments, the relevant content of a part thereof has been described in detail in another part and will not be elaborated in this part.

[0085] See also Figure 3 As shown, it is a real-time curve of the pressure inside the reactor and the pressure on the hydrocarbon discharge pipeline recorded during the shale in-situ heating simulation experiment provided by the embodiment of the present invention. The horizontal axis is time, the vertical axis is pressure, the dark gray represents the pressure inside the reactor, and the light gray represents the pressure on the hydrocarbon discharge pipeline. During the shale heating simulation experiment, the pressure inside the reactor and the hydrocarbon discharge valve changes with the reaction time after the first hydrocarbon discharge branch is blocked and the second hydrocarbon discharge branch is opened. The hydrocarbon discharge pressure during the experiment is 2.5 MPa, and the residual pressure in the reactor after each hydrocarbon discharge is 2.0 MPa. Figure 3 As shown, during the experiment, before about 4000 minutes, the pressure changes in the reactor and the hydrocarbon exhaust pipeline were consistent, changing synchronously between 2.0 and 2.5 MPa, that is, the pressure inside the reactor and the pressure on the total hydrocarbon exhaust pipeline were consistent, indicating that the hydrocarbon exhaust pipeline was unobstructed; from about 4000 minutes to 5200 minutes, the pressure in the reactor rose to 2.5 to 3 MPa, and the pressure in the hydrocarbon exhaust pipeline was maintained at 2.5 MPa. The pressure inside the reactor and the pressure on the total hydrocarbon exhaust pipeline were inconsistent, indicating that the hydrocarbon exhaust pipeline was blocked. After the second hydrocarbon exhaust branch was opened, that is, after 5200 minutes, the pressure changes in the reactor and the hydrocarbon exhaust pipeline returned to consistency, changing synchronously between 2.0 and 2.5 MPa.

[0086] The above-mentioned shale in-situ heating hydrocarbon discharge pipeline anti-blockage device, system and method provided by the embodiments of the present invention include but are not limited to the following beneficial effects: it is easy to detect whether the hydrocarbon discharge pipeline is blocked during the low-maturity shale in-situ heating experiment, ensuring that at least one hydrocarbon discharge pipeline is in an unobstructed state during the entire experiment, thereby ensuring the smooth progress of the experiment.

[0087] Unless otherwise specifically stated, terms such as processing, computing, calculating, determining, displaying, etc. may refer to the actions and / or processes of one or more processing or computing systems, or similar devices, which operate and convert data represented as physical (e.g., electronic) quantities within registers or memories of a processing system into other data similarly represented as physical quantities within memories, registers, or other such information storage, transmission, or display devices of the processing system. Information and signals may 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 may be represented by voltages, currents, 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 can be rearranged without departing from the scope of protection of the present disclosure. The attached method claims present the elements of the various steps in an exemplary order and are not intended to be limited to the specific order or hierarchy described.

[0089] In the above detailed description, various features are grouped together in a single embodiment to simplify the disclosure. This method of disclosure should not be interpreted as reflecting an intention that an embodiment of the claimed subject matter requires more features than those set forth in each claim. On the contrary, as reflected in the appended claims, the invention is in a state of having less than all the features of the disclosed individual embodiments. Therefore, the appended claims are hereby expressly incorporated into the detailed description, with each claim standing on its own as a separate preferred embodiment of the invention.

[0090] Those skilled in the art will also appreciate that the various illustrative logic blocks, modules, circuits, and algorithmic steps described in conjunction with the embodiments herein can all be implemented as electronic hardware, computer software, or a combination thereof. In order to clearly illustrate the interchangeability between hardware and software, various illustrative components, blocks, modules, circuits, and steps are generally described above around their functions. Whether such functions are implemented as hardware or software depends on specific applications and the design constraints imposed on the entire system. A skilled person can implement the described functions in an alternative manner for each specific application, but such implementation decisions should not be interpreted as departing from the scope of protection of the present disclosure.

[0091] The steps of the method or algorithm described in conjunction with the embodiments herein may be directly embodied as hardware, a software module executed by a processor, or a combination thereof. The software module may be located in a RAM memory, a flash memory, a ROM memory, an EPROM memory, an EEPROM memory, a register, a hard disk, a mobile disk, a CD-ROM, or any other form of storage medium well known in the art. An exemplary storage medium is connected to the processor so that the processor can read information from the storage medium and can write information to the storage medium. Of course, the storage medium may also be an integral part of the processor. The processor and the storage medium may be located in an ASIC. The ASIC may be located in a user terminal. Of course, the processor and the storage medium may also be present in a user terminal as discrete components.

[0092] For software implementation, the techniques described in this application can be implemented with modules (e.g., procedures, functions, etc.) that perform the functions described in this application. These software codes can be stored in a memory unit and executed by a processor. The memory unit can be implemented within the processor or outside the processor. In the latter case, it is coupled to the processor in a communication manner via various means, which are well known in the art.

[0093] The above description includes examples of one or more embodiments. Of course, it is impossible to describe all possible combinations of components or methods for describing the above embodiments, but it should be recognized by those skilled in the art that the various embodiments can be further combined and arranged. Therefore, the embodiments described herein are intended to cover all such changes, modifications and variations that fall within the scope of protection of the appended claims. In addition, with respect to the term "comprising" used in the specification or claims, the word is covered in a manner similar to the term "including", just as "including," explained as a transitional word in the claims. In addition, any term "or" used in the specification of the claims is intended to represent "non-exclusive or". The terms "first", "second", and "third" are used for descriptive purposes only and cannot be understood as indicating or implying relative importance.

Claims

1. A shale in-situ heating hydrocarbon expulsion pipeline anti-blocking device, characterized in that: include: At least two hydrocarbon exhaust branches connected to the reactor, the hydrocarbon exhaust branches comprising an inner hydrocarbon exhaust pipe and an outer hydrocarbon exhaust pipe connected via a branch control valve, the inner hydrocarbon exhaust pipe being fixedly mounted on the reactor, and the outer hydrocarbon exhaust pipe being detachably mounted outside the reactor; A main hydrocarbon exhaust pipeline connecting at least two hydrocarbon exhaust branches; A first pressure detection unit is provided on the reactor for detecting the pressure inside the reactor; A second pressure detection unit disposed on the total hydrocarbon exhaust pipeline for detecting the pressure of the total hydrocarbon exhaust pipeline; When the system is in working state, the branch control valve of at least one hydrocarbon exhaust branch is opened, and the branch control valves of other hydrocarbon exhaust branches are closed. If the difference between the pressure in the reactor and the preset hydrocarbon exhaust pressure threshold is greater than the set pressure difference threshold, and the total hydrocarbon exhaust pipeline pressure is less than or equal to the hydrocarbon exhaust pressure threshold, it is determined that the hydrocarbon exhaust branch with the branch control valve opened is blocked, and at least one other hydrocarbon exhaust branch is selected to open the branch control valve for switching.

2. The device according to claim 1, characterized in that The inner diameter of the inner hydrocarbon exhaust pipe is larger than that of the outer hydrocarbon exhaust pipe, or the ratio of the inner diameter of the inner hydrocarbon exhaust pipe to the inner diameter of the outer hydrocarbon exhaust pipe is greater than 2; the diameter of the end of the branch control valve connected to the inner hydrocarbon exhaust pipe is large, and the diameter of the end connected to the outer hydrocarbon exhaust pipe is small.

3. The device according to claim 1, characterized in that The inner diameter of the inner hydrocarbon discharge pipe is 8-10 mm, and the inner diameter of the outer hydrocarbon discharge pipe is 3-6 mm.

4. The device according to claim 1, characterized in that A solenoid valve is arranged on the main hydrocarbon exhaust pipeline, and a multi-way valve is arranged between the main hydrocarbon exhaust pipeline and at least two hydrocarbon exhaust branches.

5. The device according to claim 1, characterized in that Also includes: A third pressure detection unit is arranged on the external hydrocarbon exhaust pipe of the hydrocarbon exhaust branch for detecting the pressure of the hydrocarbon exhaust branch, so as to determine whether the hydrocarbon exhaust branch with the branch control valve opened is blocked and locate the blockage position based on the hydrocarbon exhaust branch pressure, the pressure in the reactor and the total hydrocarbon exhaust pipeline pressure, and determine whether the hydrocarbon exhaust branch with the control valve closed is in a cut-off state.

6. The system according to claim 2, characterized in that A three-way valve with a variable diameter is arranged on the side wall of the reactor body, the inner hydrocarbon exhaust pipe and the outer hydrocarbon exhaust pipe are connected through the three-way valve, and the spiral rod on the three-way valve can control the connection and disconnection between the inner hydrocarbon exhaust pipe and the outer hydrocarbon exhaust pipe.

7. A shale in-situ heating system for preventing hydrocarbon exhaust pipeline from being blocked, characterized in that: include: A reaction kettle, a control device and a shale in-situ heating hydrocarbon expulsion pipeline anti-clogging device as claimed in any one of claims 1 to 6; The control device is used to obtain the pressure inside the reactor detected by the first pressure detection unit and the total hydrocarbon exhaust pipeline pressure detected by the second pressure detection unit, and determine whether the hydrocarbon exhaust branch opened by the branch control valve is blocked based on the pressure inside the reactor, the total hydrocarbon exhaust pipeline pressure and a preset hydrocarbon exhaust pressure threshold.

8. The system according to claim 7, characterized in that The control device is also used for: The hydrocarbon exhaust branch pressure detected by the third pressure detection unit on the external hydrocarbon exhaust pipe of the hydrocarbon exhaust branch with the control valve opened is obtained, and based on the hydrocarbon exhaust branch pressure, the pressure inside the reactor and the total hydrocarbon exhaust pipeline pressure, it is determined whether the hydrocarbon exhaust branch with the branch control valve opened is blocked and the position of the blockage is located, and whether the hydrocarbon exhaust branch with the control valve closed is in a cut-off state.

9. A method for preventing clogging of shale in-situ heating and hydrocarbon expulsion pipelines, characterized in that: This is achieved by using a shale in-situ heating system for preventing blockage of hydrocarbon exhaust pipelines as described in any one of claims 7-8.

10. The method according to claim 9, characterized in that include: Select at least one hydrocarbon exhaust branch to open the branch control valve, and keep the branch control valves of other hydrocarbon exhaust branches closed; Real-time monitoring of the pressure in the reactor detected by the first pressure detection unit and the total hydrocarbon exhaust pipeline pressure detected by the second pressure detection unit, if the difference between the pressure in the reactor and a preset hydrocarbon exhaust pressure threshold is greater than the set pressure difference threshold, and the total hydrocarbon exhaust pipeline pressure is less than or equal to the hydrocarbon exhaust pressure threshold, it is determined that the hydrocarbon exhaust branch opened by the branch control valve is blocked; Select a hydrocarbon exhaust branch with a branch control valve closed, open the branch control valve, close the branch control valve of the blocked hydrocarbon exhaust branch, remove its external hydrocarbon exhaust pipe, dredge it, and then install it again.

11. The method according to claim 9 or 10, characterized in that Also includes: Real-time monitoring of the hydrocarbon exhaust branch pressure detected by the third pressure detection unit on the external hydrocarbon exhaust pipe of each hydrocarbon exhaust branch; Based on the hydrocarbon exhaust branch pressure, the pressure in the reactor and the total hydrocarbon exhaust pipeline pressure, it is determined whether the hydrocarbon exhaust branch with the branch control valve opened is blocked and the blockage position is located, and it is determined whether the hydrocarbon exhaust branch with the control valve closed is in a cut-off state.

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