Interwell pressure channeling early warning method, channeling prevention method and system, computer equipment and medium

Abstract

The invention provides an inter-well pressure channeling early warning method, a channeling prevention method, a channeling prevention system, computer equipment and a medium. The early warning method comprises the following steps: measuring an initial background magnetic field and an external magnetic field; the magnetofluid and the fracturing fluid are pressurized and then injected into a shaft; detecting an intensified magnetic field after the magnetofluid enters the stratum in real time, and performing data preprocessing to obtain magnetic anomaly data; positioning each magnetofluid magnetic anomaly section in the reservoir to obtain the expansion direction and distance of the fracturing fluid in the reservoir; calculating the distance between the front end of the fracturing fluid and the adjacent well; and dividing different alarm levels, and carrying out early warning on pressure channeling of adjacent wells. The anti-channeling method comprises the steps that according to the early warning level, the output power of the high-pressure pump set is reduced, and the temporary plugging agent is added in a segmented mode. By means of the system, inter-well pressure channeling early warning and channeling prevention can be achieved. The computer equipment and the medium are used for implementing the method. The method has the function of quantitatively obtaining the well channeling communication area / range / direction, has the advantage of being low in cost, and can conduct early warning before well channeling occurs.

Description

Technical Field

[0001] The present invention belongs to the technical field of oil and gas development, and specifically, relates to a magnetic fluid-based inter-well pressure channeling warning method, a magnetic fluid-based inter-well pressure channeling prevention method, a magnetic fluid-based inter-well pressure channeling warning and prevention system, and a computer device for implementing the magnetic fluid-based inter-well pressure channeling warning and prevention method and a computer-readable storage medium for implementing the magnetic fluid-based inter-well pressure channeling warning and prevention method. Background Art

[0002] Throughout the world, most shale gas reservoirs in North America and China generally adopt a "rolling development" plan with large well spacing in the early stage of development and intensification in the later stage, which easily leads to well pressure channeling between old wells and new wells, seriously affecting the production capacity of oil and gas wells. Well pressure channeling will cause serious harm to new and old wells. Data statistics show that the well interference problem of fractured shale gas reservoirs at home and abroad is as high as more than 40%. It is necessary to solve the impact of pressure channeling on the production capacity of new and old wells and avoid the safety risks of pressure channeling.

[0003] At present, through microseismic pressure monitoring and tracer analysis, a method for evaluating the effectiveness of fractures and an understanding of the distribution of fractures have been formed. Through microseismic technology, the process of fracture expansion during fracturing operations can be understood in real time, but the cost of microseismic technology is high. Through pressure monitoring and inter-well tracer technology, only a qualitative determination can be made as to whether well channeling has occurred, but the area / range / direction of well channeling communication cannot be quantitatively obtained. At the same time, no early warning can be given before well channeling occurs.

[0004] Nano magnetic fluid is a special functional material. It is a uniform and stable colloidal solution formed by wrapping a layer of long-chain surfactant in nano-magnetic particles (about 10 nanometers) and evenly dispersing them in a base fluid. Magnetic fluid is composed of nano magnetic particles, base fluid and surfactant. At present, nano magnetic fluid has not been applied to reservoir pressure channeling identification and anti-channeling. Summary of the invention

[0005] The purpose of the present invention is to solve at least one of the above-mentioned deficiencies in the prior art. For example, one of the purposes of the present invention is to quantify the pressure channel, and the second purpose is to provide an early warning of pressure channeling in adjacent wells based on the distance between the front end of the fracturing fluid and the adjacent well.

[0006] In order to achieve the above objectives, one aspect of the present invention provides an inter-well pressure crossover early warning based on magnetic fluid.

[0007] The early warning method may include the following steps: measuring the initial background magnetic field and measuring the external magnetic field generated by the downhole external magnetic field generator; injecting the magnetic fluid and fracturing fluid into the wellbore of the fracturing well after pressurizing; real-time detection of the enhanced magnetic field after the magnetic fluid enters the formation, and obtaining magnetic anomaly data after data preprocessing of the detected enhanced magnetic field; locating the magnetic anomaly sections of each magnetic fluid in the reservoir according to the magnetic anomaly data, and obtaining the expansion direction and distance of the fracturing fluid in the reservoir; calculating the distance between the front end of the fracturing fluid and the adjacent well according to the expansion direction and distance of the fracturing fluid in the reservoir; dividing different alarm levels according to the distance between the front end of the fracturing fluid and the adjacent well, and giving an early warning of the adjacent well pressure channeling.

[0008] In an exemplary embodiment of a magnetic fluid-based well-to-well pressure crossover early warning method of the present invention, the magnetic fluid may be added intermittently.

[0009] In an exemplary embodiment of a magnetic fluid-based well-to-well pressure channeling early warning method of the present invention, the enhanced magnetic field is generated by superposition of a background magnetic field, an external magnetic field and a secondary magnetic field.

[0010] In an exemplary embodiment of a magnetic fluid-based well-to-well pressure crossover warning method of the present invention, the alarm levels include: three levels of alarm, when the distance between the front end of the fracturing fluid and the adjacent well is less than 5 meters, it is a first level warning; when the distance between the front end of the fracturing fluid and the adjacent well is between 5 and 10 meters, it is a second level warning; when the distance between the front end of the fracturing fluid and the adjacent well is between 10 and 30 meters, it is a third level warning.

[0011] In an exemplary embodiment of a magnetic fluid-based well pressure crossover early warning method of the present invention, the distance between the front end of the fracturing fluid and the adjacent well can be calculated by maximum circumferential tensile stress theory.

[0012] On the other hand, the present invention provides a method for preventing well pressure crossover based on magnetic fluid. The method adopts different well pressure crossover warning levels obtained by the well pressure crossover warning method as described above, reduces the output power of the high-pressure pump group, and adds a temporary plugging agent; the method for adding the temporary plugging agent is to add it in stages, after adding the first stage of temporary plugging agent, add magnetic fluid, and the volume of the added magnetic fluid is greater than the volume of the nano magnetic fluid added in other times.

[0013] In an exemplary embodiment of a magnetic fluid-based well pressure crossover prevention method of the present invention, when the well pressure crossover warning method is the first level warning, the output power of the high-pressure pump group is reduced by 50%, and a temporary plugging agent with a concentration of 3.0% to 10.0% is added.

[0014] When the inter-well pressure channeling warning method is the second-level warning, the output power of the high-pressure pump group is reduced by 30%, and a temporary plugging agent with a concentration of 1.6% to 3.0% is added.

[0015] When the inter-well pressure channeling warning method is the third level warning, the output power of the high-pressure pump group is reduced by 10%, and a temporary plugging agent with a concentration of 1.0% to 1.6% is added.

[0016] On the other hand, the present invention provides a magnetic fluid-based well pressure channeling warning and anti-channeling system, the system comprising: a fracturing fluid container, a temporary plugging agent storage tank, a magnetic fluid container, a high-pressure pump group, a downhole magnetic field generator, a magnetometer group, a data acquisition and processing module, a pressure channeling warning module and an anti-channeling module, wherein the fracturing fluid container is used to store fracturing fluid; the temporary plugging agent storage tank is connected to the fracturing fluid container and is used to store the temporary plugging agent; the magnetic fluid container is used to store nano magnetic fluid; the inlet of the high-pressure pump group is respectively connected to the fracturing fluid container and the magnetic fluid container, and the outlet of the high-pressure pump group is connected to the fracturing well, and is used to pressurize the magnetic fluid and fracturing fluid and inject them into the wellbore of the fracturing well; the downhole magnetic field generator is arranged inside the fracturing well, and is used to generate an external magnetic field; the magnetometer group includes a plurality of magnetometers, and the magnetometers are arranged in adjacent wells of the fracturing well, and are used to measure the initial background magnetic field and the downhole external magnetic field generation. The external magnetic field generated by the device is used to locate the specific position of each magnetic fluid abnormal section in the reservoir through multiple magnetometers; the data acquisition and processing module is connected to each magnetometer, and is used to analyze and process the enhanced magnetic field after the magnetic fluid enters the formation, and obtain magnetic anomaly data after data preprocessing is performed on the detected enhanced magnetic field; the pressure channeling warning module is connected to the data acquisition and processing module, and according to the magnetic anomaly data, each magnetic fluid magnetic anomaly section in the reservoir is located, and the expansion direction and distance of the fracturing fluid in the reservoir are obtained. According to the expansion direction and distance of the fracturing fluid in the reservoir, the distance between the front end of the fracturing fluid and the adjacent well is calculated, and different alarm levels are divided according to the distance between the front end of the fracturing fluid and the adjacent well, and an alarm is issued for pressure channeling of the adjacent well; the anti-channeling module is connected to the pressure channeling warning module, and according to different inter-well pressure channeling warning levels, the output power of the high-pressure pump group is reduced, and a temporary plugging agent is added.

[0017] Another aspect of the present invention provides a computer device, which may include: a processor; a memory storing a computer program, and when the computer program is executed by the processor, the well-to-well pressure crossover warning method applicable to magnetic fluids, or the well-to-well pressure crossover prevention method applicable to magnetic fluids as described above is implemented.

[0018] On the other hand, the present invention provides a computer-readable storage medium storing a computer program, which, when executed by a processor, implements the well-to-well pressure crossover warning method applicable to magnetic fluids as described above, or the well-to-well pressure crossover prevention method applicable to magnetic fluids as described above.

[0019] Compared with the prior art, the beneficial effects of the present invention may include at least one of the following:

[0020] (1) The present invention injects nanomagnetic fluid into the fracturing well and arranges a corresponding magnetometer group in the adjacent well. The expansion process of the fracturing fluid in the reservoir is located by the magnetic field of the nanomagnetic fluid, so as to judge the distance between the front end of the fracturing fluid and the adjacent well, and issue a corresponding alarm when the distance is lower than a preset value. It has the advantages of quantitatively obtaining the communication area / range / direction of the well channeling and low cost, and can also issue an early warning before the well channeling occurs;

[0021] (2) The present invention adopts the method of intermittently adding nano-magnetic fluid, so that when the fracturing fluid flows in the reservoir, the nano-magnetic fluid can form a number of magnetic anomaly segments distributed along the trajectory of the fracturing fluid. By monitoring the migration trajectory of each magnetic anomaly segment, the migration direction of the fracturing fluid at each location in the reservoir is obtained, providing more accurate data support for the identification of inter-well pressure channeling;

[0022] (3) The present invention adds nanomagnetic fluid after adding the first stage of temporary plugging agent, and the volume of the nanomagnetic fluid added at this time should be much larger than the volume of the nanomagnetic fluid added in other times, so that the position of the temporary plugging agent in the reservoir can be determined, and the use effect of the temporary plugging agent can be judged according to the position distribution of the magnetic fluid near the temporary plugging agent. If the use effect of the temporary plugging agent is not good, the type and amount of the temporary plugging agent can be replaced. Therefore, the present method can also be used to test the use effect of the temporary plugging agent, thereby providing guidance for the development of the temporary plugging agent. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 The structure diagram of the well pressure channeling warning and anti-channeling method of Example 1 of the present invention is shown;

[0024] Figure 2 A schematic diagram showing the positional relationship between the magnetic fluid and the temporary plugging agent of Example 1 of the present invention is shown;

[0025] Figure 3 A schematic diagram of the system structure of Example 2 of the present invention is shown;

[0026] Figure 4 A schematic diagram of the computer device structure of Example 3 of the present invention is shown.

[0027] Description of reference numerals:

[0028] A01-temporary plugging agent storage tank, A02-fracturing fluid container, A03-high-pressure pump group, A04-magnetic fluid container, A05-data acquisition and processing center, A06-downhole magnetic field generator, A07-magnetic fluid, A08-fracturing well, A09-magnetometer group, A10-adjacent well, A-position where temporary plugging agent is added, B-magnetic fluid, 100-early warning and anti-channeling system, 110-fracturing fluid container, 120-temporary plugging agent storage tank, 130-magnetic fluid container, 140-high-pressure pump group, 150-downhole magnetic field generator, 160-magnetometer group, 170-data acquisition and processing module, 180-pressure channeling early warning module, 190-anti-channeling module, 200-computer equipment, 210-memory, 220-processor. DETAILED DESCRIPTION

[0029] Hereinafter, the well-to-well pressure crossover warning method, crossover prevention method, system, computer device and medium of the present invention will be described in detail with reference to the accompanying drawings and exemplary embodiments.

[0030] In the description of the present invention, it should be noted that "first" and "second" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, unless otherwise specified, "plurality" means two or more.

[0031] On one hand, the present invention provides a magnetic fluid-based well pressure channeling early warning method.

[0032] In an exemplary embodiment of a magnetic fluid-based well pressure crossover early warning method of the present invention, the early warning method may include the following steps:

[0033] The initial background magnetic field is measured, and the external magnetic field generated by the downhole external magnetic field generator is measured.

[0034] The magnetic fluid and fracturing fluid are pressurized and injected into the wellbore of the fracturing well.

[0035] Specifically, the magnetic fluid can be added intermittently.

[0036] The enhanced magnetic field after the magnetic fluid enters the formation is detected in real time, and the magnetic anomaly data is obtained after data preprocessing of the detected enhanced magnetic field.

[0037] Specifically, the enhanced magnetic field can be generated by the superposition of the background magnetic field, the external magnetic field and the secondary magnetic field.

[0038] According to the magnetic anomaly data, each magnetic anomaly section of the magnetic fluid in the reservoir is located to obtain the expansion direction and distance of the fracturing fluid in the reservoir.

[0039] According to the expansion direction and distance of the fracturing fluid in the reservoir, the distance between the front end of the fracturing fluid and the adjacent well is calculated. Specifically, the expansion direction of the fracturing fluid in the reservoir can be calculated by the maximum circumferential tensile stress theory, and the distance between the front end of the fracturing fluid and the adjacent well can be calculated at the same time.

[0040] Different alarm levels are divided according to the distance between the front end of the fracturing fluid and the adjacent well, so as to give an early warning of the fracturing in the adjacent well.

[0041] Specifically, the alarm levels include: three levels of alarm, when the distance between the front end of the fracturing fluid and the adjacent well is less than 5 meters, it is the first level warning; when the distance between the front end of the fracturing fluid and the adjacent well is between 5 and 10 meters, it is the second level warning; when the distance between the front end of the fracturing fluid and the adjacent well is between 10 and 30 meters, it is the third level warning.

[0042] Another aspect of the present invention provides a method for preventing pressure channeling based on magnetic fluid.

[0043] In an exemplary embodiment of a magnetic fluid-based well pressure crossover prevention method of the present invention, the crossover prevention method may include the following steps:

[0044] According to the different inter-well pressure channeling warning levels obtained by the above pressure channeling warning method, the output power of the high-pressure pump group is reduced and a temporary plugging agent is added.

[0045] The method of adding the temporary plugging agent is to add it in stages. After adding the first stage of temporary plugging agent, the magnetic fluid is added, and the volume of the added magnetic fluid is greater than the volume of the nano magnetic fluid added in other times.

[0046] Specifically, when the inter-well pressure channeling warning method is the first level warning, the output power of the high-pressure pump group is reduced by 50%, and a temporary plugging agent with a concentration of 3.0% to 10.0% is added.

[0047] When the inter-well pressure channeling warning method is the second-level warning, the output power of the high-pressure pump group is reduced by 30%, and a temporary plugging agent with a concentration of 1.6% to 3.0% is added.

[0048] When the inter-well pressure channeling warning method is the third level warning, the output power of the high-pressure pump group is reduced by 10%, and a temporary plugging agent with a concentration of 1.0% to 1.6% is added.

[0049] Another aspect of the present invention provides a magnetic fluid-based well pressure channeling warning and prevention system.

[0050] In an exemplary embodiment of a magnetic fluid-based well pressure crossover warning and crossover prevention system of the present invention, the warning and crossover prevention system may include:

[0051] Fracturing fluid container, temporary plugging agent storage tank, magnetic fluid container, high-pressure pump group, downhole magnetic field generator, magnetometer group, data acquisition and processing module, pressure channeling warning module and anti-channeling module.

[0052] Among them, the fracturing fluid container is used to store fracturing fluid.

[0053] The temporary plugging agent storage tank is connected to the fracturing fluid container and is used to store the temporary plugging agent.

[0054] The magnetic fluid container is used to store nano magnetic fluid.

[0055] The inlet of the high-pressure pump group is connected to the fracturing fluid container and the magnetic fluid container respectively, and the outlet of the high-pressure pump group is connected to the fracturing well, which is used to inject the magnetic fluid and fracturing fluid into the wellbore of the fracturing well after pressurization.

[0056] The downhole magnetic field generator is arranged inside the fracturing well to generate an external magnetic field.

[0057] The magnetometer group includes several magnetometers, which are set in the adjacent wells of the fracturing well to measure the initial background magnetic field and the external magnetic field generated by the downhole external magnetic field generator. The specific positions of various magnetic fluid abnormal sections in the reservoir are located through multiple magnetometers.

[0058] The data acquisition and processing module is connected to the magnetometer group and is used to analyze and process the enhanced magnetic field after the magnetic fluid enters the formation, and obtain magnetic anomaly data after data preprocessing of the detected enhanced magnetic field.

[0059] The pressure channeling warning module is connected to the data acquisition and processing module. According to the magnetic anomaly data, each magnetic fluid magnetic anomaly section in the reservoir is located to obtain the expansion direction and distance of the fracturing fluid in the reservoir. According to the expansion direction and distance of the fracturing fluid in the reservoir, the distance between the front end of the fracturing fluid and the adjacent well is calculated. Different alarm levels are divided according to the distance between the front end of the fracturing fluid and the adjacent well, and an early warning is issued for pressure channeling in the adjacent well.

[0060] The anti-channeling module is connected to the pressure channeling warning module. According to different inter-well pressure channeling warning levels, the output power of the high-pressure pump group is reduced and a temporary plugging agent is added.

[0061] According to an exemplary embodiment of another aspect of the present invention, a computer-readable storage medium storing a computer program is also provided. The computer-readable storage medium stores a computer program that, when executed by a processor, causes the processor to execute a method for early warning of well-to-well pressure channeling for magnetic fluids, or a method for preventing well-to-well pressure channeling for magnetic fluids according to the present invention. The computer-readable recording medium is any data storage device that can store data read out by a computer system. Examples of computer-readable recording media include: read-only memory, random access memory, read-only optical disk, magnetic tape, floppy disk, optical data storage device, and carrier wave (such as data transmission over the Internet via a wired or wireless transmission path).

[0062] According to another exemplary embodiment of the present invention, a computer device is also provided. The computer device includes a processor and a memory. The memory is used to store a computer program. The computer program is executed by the processor so that the processor executes the computer program of the well-to-well pressure channeling warning method applicable to magnetic fluid or the well-to-well pressure channeling prevention method applicable to magnetic fluid according to the present invention.

[0063] In order to better understand the present invention, the content of the present invention is further explained below with reference to the accompanying drawings and examples, but the content of the present invention is not limited to the following embodiments.

[0064] Example 1

[0065] Figure 1 The structural diagram of the well-to-well pressure crossover warning and prevention method of this example is shown. Figure 1 The intermediate temporary plugging agent storage tank A01 is connected to the fracturing fluid container A02, the high-pressure pump group A03 is connected to the magnetic fluid container A04, the high-pressure pump group A03 is used to pump the fracturing fluid and the magnetic fluid into the fracturing well A08, the downhole magnetic field generator A06 is used to generate an external magnetic field, the magnetic fluid A07 in the fracturing layer is used to form a number of magnetic anomaly segments, the data acquisition and processing center A05 is connected to the magnetometer group A09, and is used to detect the magnetic anomaly data in the adjacent well A10, and transmit it to the real-time data acquisition and processing center A05 through the communication line for data preprocessing, and finally realize the real-time positioning of each magnetic anomaly segment of the magnetic fluid in the reservoir.

[0066] Step 1: Equipment layout and assembly.

[0067] A downhole magnetic field generator is arranged near a predetermined fracturing layer section in the wellbore of the fracturing well, and several magnetometers are arranged near the corresponding layer section in the wellbore of the adjacent well, and connected to the data acquisition and processing center through communication lines.

[0068] Step 2: Start each magnetometer and measure the initial background magnetic field.

[0069] Step 3: Start the downhole external magnetic field generator of the fracturing well, and use each magnetometer to measure the external magnetic field generated by the downhole external magnetic field generator.

[0070] Step 4: The nano magnetic fluid and fracturing fluid are transported to the high-pressure pump group through the delivery pipeline, and after being pressurized, they are injected into the wellbore of the fracturing well through the delivery pipeline.

[0071] In step 4, the nanomagnetic fluid is added in an intermittent manner, so that after the nanomagnetic fluid enters the fracturing layer, the nanomagnetic fluid is distributed discontinuously. Compared with the continuous distribution, the discontinuous distribution has the advantages of reducing the usage of the nanomagnetic fluid, thereby reducing the cost, and on the other hand, by adopting the intermittent addition method (the volume of the magnetic fluid added each time is equal), when the fracturing fluid flows in the reservoir, the nanomagnetic fluid forms a number of magnetic anomaly segments, and the magnetic anomaly segments are distributed along the trajectory of the fracturing fluid, so that the migration direction of the fracturing fluid at various locations in the reservoir can be obtained by monitoring the migration trajectory of each magnetic anomaly segment, providing more accurate data support for the identification of inter-well pressure channeling. Figure 2 A schematic diagram showing the positional relationship between the magnetic fluid and the temporary plugging agent of this example is shown. In the figure, A represents the position where the temporary plugging agent is added; B represents the magnetic fluid; and the blank part between the two sections of magnetic fluid represents the temporary plugging agent.

[0072] Step 5: As the fracturing fluid and nano-magnetic fluid are continuously injected into the wellbore, the nano-magnetic fluid injected in step 4 is continuously pushed into the formation and magnetized to form a secondary magnetic field under the action of an external magnetic field. When the fracturing fluid flows in the reservoir, the nano-magnetic fluid forms a number of magnetic anomaly segments, which are distributed along the trajectory of the fracturing fluid. The enhanced magnetic field formed by the superposition of the background magnetic field, the external magnetic field and the secondary magnetic field after the magnetic fluid enters the formation is detected in real time by various magnetometers, and is transmitted to the real-time data acquisition and processing center through a communication line. After the data is pre-processed, the magnetic anomaly data is obtained. According to the magnetic anomaly data, the magnetic anomaly segments of each magnetic fluid in the reservoir are located in real time, so that the expansion direction and distance of the fracturing fluid in the reservoir can be obtained.

[0073] Step 6: Provide early warning of fracturing in adjacent wells based on the expansion direction and distance of the fracturing fluid in the reservoir.

[0074] The specific method is to calculate the distance between the front end of the fracturing fluid and the adjacent wells through the expansion direction and distance of the fracturing fluid in the reservoir, and to issue an adjacent well pressure channeling warning based on the distance between the front end of the fracturing fluid and the adjacent wells.

[0075] The expansion direction of the fracturing fluid in the reservoir and the distance between the front end of the fracturing fluid and the adjacent well can be calculated by the maximum circumferential tensile stress theory.

[0076] Step 7: Different alarm levels are divided according to the distance between the front end of the fracturing fluid and the adjacent well.

[0077] For example:

[0078] When the distance between the front end of the fracturing fluid and the adjacent well is between 10 and 30 meters, the system will issue a third-level warning.

[0079] When the distance between the front end of the fracturing fluid and the adjacent well is between 5 and 10 meters, the system will issue a second-level warning.

[0080] When the distance between the front end of the fracturing fluid and the adjacent well is less than 5 meters, the system issues a level one warning.

[0081] It should be understood that those skilled in the art can adjust the size of relevant thresholds according to actual geological and development conditions, and set different anti-channeling schemes for different alarm levels.

[0082] (1) When the system issues a third-level warning, the output power of the high-pressure pump group is reduced by 10%. At the same time, a temporary plugging agent is added. At this time, it should be noted that the temporary plugging agent and the nano-magnetic fluid are added in intervals, that is, after adding a section of nano-magnetic fluid, another section of temporary plugging agent is added. At the same time, in order to facilitate the determination of the position of the temporary plugging agent in the reservoir, the nano-magnetic fluid is added immediately after the first section of temporary plugging agent is added, and the volume of the nano-magnetic fluid added at this time should be much larger than the volume of the nano-magnetic fluid added in other times. Figure 3 As shown in the example, the volume of the nanomagnetic fluid added each time is 3m 3 The volume of nano magnetic fluid added after adding the first temporary plugging agent is 9m 3 Therefore, during inversion interpretation, the position of the temporary plugging agent can be determined by the position of the nanomagnetic fluid segment with a larger monomer volume in the reservoir, and the effect of the temporary plugging agent can be determined based on the position distribution of the magnetic fluid near the temporary plugging agent.

[0083] If the temporary plugging agent has a poor effect, the type and amount of the temporary plugging agent can be changed, so that this method can also be used to test the effect of the temporary plugging agent.

[0084] When implementing the corresponding anti-channeling plan, the distance between the front end of the fracturing fluid and the adjacent well should be continuously monitored to see whether it continues to decrease. If the front end of the fracturing fluid no longer continues to expand forward or the expansion speed decreases rapidly, the addition of temporary plugging agent can be cancelled, but the output power of the high-pressure pump group remains unchanged.

[0085] (2) When the system issues a second-level warning, the output power of the high-pressure pump group is reduced by 30%, and at the same time, a larger dose of temporary plugging agent is added.

[0086] The method of adding the temporary plugging agent is the same as the above scheme, which will not be described in detail.

[0087] (3) When the system issues a first-level warning, the output power of the high-pressure pump group is reduced by 50%, and at the same time, a larger dose of temporary plugging agent is added.

[0088] Example 2

[0089] like Figure 3 As shown, the early warning and anti-channeling system 100 includes: a fracturing fluid container 110, a temporary plugging agent storage tank 120, a magnetic fluid container 130, a high-pressure pump group 140, a downhole magnetic field generator 150, a magnetometer group 160, a data acquisition and processing module 170, a pressure channeling early warning module 180 and an anti-channeling module 190.

[0090] The fracturing fluid container 110 is used to store the fracturing fluid.

[0091] The temporary plugging agent storage tank 120 is connected to the fracturing fluid container 110 and is used to store the temporary plugging agent.

[0092] The magnetic fluid container 130 is used to store nano magnetic fluid.

[0093] The inlet of the high-pressure pump group 140 is connected to the fracturing fluid container 110 and the magnetic fluid container 130 respectively, and the outlet of the high-pressure pump group 140 is connected to the fracturing well for pressurizing the magnetic fluid and fracturing fluid and injecting them into the wellbore of the fracturing well.

[0094] The downhole magnetic field generator 150 is disposed inside the fracturing well to generate an external magnetic field.

[0095] The magnetometer group 160 includes several magnetometers, which are set in the adjacent wells of the fracturing well to measure the initial background magnetic field and the external magnetic field generated by the downhole external magnetic field generator. The specific positions of various magnetic fluid abnormal sections in the reservoir are located by multiple magnetometers.

[0096] The data acquisition and processing module 170 is connected to the magnetometer group 160 and is used to analyze and process the enhanced magnetic field after the magnetic fluid enters the formation, and obtain magnetic anomaly data after data preprocessing of the detected enhanced magnetic field.

[0097] The pressure channeling warning module 180 is connected to the data acquisition and processing module 170. According to the magnetic anomaly data, each magnetic anomaly segment of the magnetic fluid in the reservoir is located to obtain the expansion direction and distance of the fracturing fluid in the reservoir. According to the expansion direction and distance of the fracturing fluid in the reservoir, the distance between the front end of the fracturing fluid and the adjacent well is calculated. Different alarm levels are divided according to the distance between the front end of the fracturing fluid and the adjacent well, and an early warning is issued for pressure channeling in the adjacent well.

[0098] The anti-channeling module 190 is connected to the pressure channeling warning module 180. According to different inter-well pressure channeling warning levels, the output power of the high-pressure pump group is reduced and a temporary plugging agent is added.

[0099] Example 3

[0100] like Figure 4As shown, a computer device 200 includes a memory 210 and a processor 220. The memory 210 stores a computer program. When the computer program is executed by the processor, the above-mentioned inter-well pressure channeling warning and prevention method is implemented.

[0101] Although the present invention has been described above by combining with exemplary embodiments, it will be apparent to those skilled in the art that various modifications and changes may be made to the exemplary embodiments of the present invention without departing from the spirit and scope defined in the claims.

Claims

1. A magnetic fluid-based well pressure channeling early warning method, characterized in that: The method comprises the following steps: Measuring the initial background magnetic field and measuring the external magnetic field generated by the downhole external magnetic field generator; The magnetic fluid and the fracturing fluid are pressurized and injected into the wellbore of the fracturing well; Real-time detection of the enhanced magnetic field after the magnetic fluid enters the formation, and the magnetic anomaly data is obtained after data preprocessing of the detected enhanced magnetic field; According to the magnetic anomaly data, each magnetic fluid magnetic anomaly section in the reservoir is located to obtain the expansion direction and distance of the fracturing fluid in the reservoir; According to the expansion direction and distance of the fracturing fluid in the reservoir, the distance between the front end of the fracturing fluid and the adjacent well is calculated; Different alarm levels are set according to the distance between the front end of the fracturing fluid and the adjacent wells to provide early warning of fracturing in the adjacent wells.

2. The well pressure channeling early warning method according to claim 1 is characterized in that: The magnetic fluid is added in an intermittent manner.

3. The well pressure channeling early warning method according to claim 1 is characterized in that: The enhanced magnetic field is generated by the superposition of the background magnetic field, the external magnetic field and the secondary magnetic field.

4. The well pressure channeling early warning method according to claim 1, characterized in that: The alarm levels include: three levels of alarm, when the distance between the front end of the fracturing fluid and the adjacent well is less than 5 meters, it is the first level warning; when the distance between the front end of the fracturing fluid and the adjacent well is between 5 and 10 meters, it is the second level warning; when the distance between the front end of the fracturing fluid and the adjacent well is between 10 and 30 meters, it is the third level warning.

5. The well pressure channeling early warning method according to claim 1, characterized in that: The distance between the front end of the fracturing fluid and the adjacent well is calculated by maximum circumferential tensile stress theory.

6. A method for preventing well pressure channeling based on magnetic fluid, wherein the method reduces the output power of the high-pressure pump group and adds a temporary plugging agent according to different well pressure channeling warning levels obtained by the method according to any one of claims 1 to 5; The method of adding the temporary plugging agent is to add it in stages. After adding the first stage of temporary plugging agent, the magnetic fluid is added, and the volume of the added magnetic fluid is greater than the volume of the nano magnetic fluid added in other times.

7. The method for preventing well pressure channeling according to claim 6, characterized in that: When the inter-well pressure channeling warning method is the first level warning, the output power of the high-pressure pump group is reduced by 50%, and a temporary plugging agent with a concentration of 3.0% to 10.0% is added; When the inter-well pressure channeling warning method is the second-level warning, the output power of the high-pressure pump group is reduced by 30%, and a temporary plugging agent with a concentration of 1.6% to 3.0% is added; When the inter-well pressure channeling warning method is the third level warning, the output power of the high-pressure pump group is reduced by 10%, and a temporary plugging agent with a concentration of 1.0% to 1.6% is added.

8. A magnetic fluid-based well pressure channeling warning and anti-channeling system, the system comprising: Fracturing fluid container, temporary plugging agent storage tank, magnetic fluid container, high-pressure pump group, downhole magnetic field generator, magnetometer group, data acquisition and processing module, pressure channeling warning module and anti-channeling module, among which, The fracturing fluid container is used to store the fracturing fluid; The temporary plugging agent storage tank is connected to the fracturing fluid container and is used to store the temporary plugging agent; The magnetic fluid container is used to store nano magnetic fluid; The inlet of the high-pressure pump group is connected to the fracturing fluid container and the magnetic fluid container respectively, and the outlet of the high-pressure pump group is connected to the fracturing well, so as to inject the magnetic fluid and fracturing fluid into the wellbore of the fracturing well after pressurization; The downhole magnetic field generator is arranged inside the fracturing well to generate an external magnetic field; The magnetometer group includes several magnetometers, which are set in the adjacent wells of the fracturing well to measure the initial background magnetic field and the external magnetic field generated by the downhole external magnetic field generator. The specific positions of each abnormal magnetic fluid section in the reservoir are located by multiple magnetometers; The data acquisition and processing module is connected to the magnetometer group and is used to analyze and process the enhanced magnetic field after the magnetic fluid enters the formation, and obtain magnetic anomaly data after data preprocessing of the detected enhanced magnetic field; The pressure channeling warning module is connected to the data acquisition and processing module. According to the magnetic anomaly data, each magnetic fluid magnetic anomaly section in the reservoir is located to obtain the expansion direction and distance of the fracturing fluid in the reservoir. According to the expansion direction and distance of the fracturing fluid in the reservoir, the distance between the front end of the fracturing fluid and the adjacent well is calculated. Different alarm levels are divided according to the distance between the front end of the fracturing fluid and the adjacent well, and an early warning is issued for pressure channeling in the adjacent well. The anti-channeling module is connected to the pressure channeling warning module. According to different inter-well pressure channeling warning levels, the output power of the high-pressure pump group is reduced and a temporary plugging agent is added.

9. A computer device, characterized in that: The computer device comprises: processor; A memory storing a computer program, which, when executed by a processor, implements the well-to-well pressure crossover warning method applicable to magnetic fluids as described in any one of claims 1 to 5, or the well-to-well pressure crossover prevention method applicable to magnetic fluids as described in any one of claims 6 to 7.

10. A computer-readable storage medium storing a computer program, characterized in that: When the computer program is executed by the processor, the well-to-well pressure crossover warning method applicable to magnetic fluid as described in any one of claims 1 to 5, or the well-to-well pressure crossover prevention method applicable to magnetic fluid as described in any one of claims 6 to 7 is implemented.

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