Crack plugging layer real-time monitoring device and method

Abstract

The invention provides a real-time monitoring device and method for a crack plugging layer, and the device comprises an optical fiber module, a modulation and demodulation module connected with the optical fiber module, a storage container which is internally provided with plugging liquid, a pressure pump connected with the storage container, and a crack simulation module which is connected with the storage container and is internally provided with a crack plate, the pressure pump pressurizes the plugging liquid in the storage container and drives the plugging liquid to flow out between crack plates to form a plugging layer, and the optical fiber module is arranged in the crack simulation module and used for monitoring the pressure change in the crack simulation module in real time and transmitting the pressure change to the modulation-demodulation module through a signal; and the modulation-demodulation module is used for presenting the distribution of the plugging layer in the crack simulation module according to the signal. According to the invention, the actual stratum leakage characteristics can be simulated, and the change of the position of the plugging layer can be rapidly monitored in real time.

Description

Technical Field

[0001] The invention relates to the technical field of testing for oil drilling, and in particular to a device and method for real-time monitoring of a crack sealing layer. Background Art

[0002] As domestic oil and gas resource exploration and development gradually shifts to deep and ultra-deep oil and gas fields, the strata encountered during drilling are becoming more and more complex. Affected by geological structures, deep oil and gas layers and their overlying strata usually develop a large number of natural fractures, and drilling fluid loss is very likely to occur during well construction. The types of drilling fluid loss in deep oil and gas layers are complex and the amount of loss is large, which brings serious economic losses to drilling projects. During the loss process, granular materials need to be added to the drilling fluid to form an efficient and tight sealing layer in the leaking fractures, thereby controlling and even eliminating the loss. This technology is often called bridging plugging technology in the field of petroleum engineering.

[0003] During the plugging process, the solid particles and plugging materials in the drilling fluid enter the cracks with the loss of drilling fluid and are deposited in the cracks to gradually form a plugging layer. After the plugging layer is formed, it will affect the redistribution of crack deformation, tangential stress around the well and stress intensity factor at the crack tip. Therefore, the location of the plugging layer has a great influence on the plugging effect. If the plugging layer is too close to the crack mouth, the circulating drilling fluid will easily cause the plugging layer to fail and induce re-leakage. If the plugging layer is too close to the crack tip, it may cause the crack to expand, further increasing the risk of leakage.

[0004] Based on this, evaluating the formation position of the plugging layer has become a key experiment for evaluating the optimal particle size of bridging plugging materials. Currently, there are two common methods for evaluating the position of the plugging layer: the first is to use steel fracture cores to carry out pressure plugging experiments, separate the cores after the experiment, and observe the position of the plugging layer; the second is to use organic glass plates to make fracture rock samples and observe the changes in the position of the plugging layer. However, the first method cannot observe the formation process of the plugging layer in real time, and the second method has a low drilling fluid pressure during the experiment, which cannot simulate the actual formation leakage characteristics, and it is also impossible to observe the formation process of the plugging layer in real time.

[0005] The existing evaluation method of the plugging layer position of bridging plugging cannot achieve real-time monitoring of the plugging layer position under high-pressure environment, resulting in insufficient understanding of the deep bridging plugging mechanism and relatively lagging plugging technology research and development. Summary of the invention

[0006] One object of the present invention is to provide a real-time monitoring device and method for a fracture plugging layer, so as to simulate the actual formation leakage characteristics and to monitor the change of the plugging layer position in real time and quickly.

[0007] According to the present invention, a real-time monitoring device for a crack plugging layer is provided, comprising: an optical fiber module, a modulation and demodulation module connected to the optical fiber module, a storage container with plugging liquid inside, a pressure pump connected to the storage container, and a crack simulation module connected to the storage container and having a crack seam plate inside, wherein the pressure pump pressurizes the plugging liquid in the storage container and drives it to flow out between the crack seams to form a plugging layer, the optical fiber module is arranged inside the crack simulation module, and is used to monitor the pressure change inside the crack simulation module in real time and transmit the pressure to the modulation and demodulation module through a signal, and the modulation and demodulation module is used to present the distribution of the plugging layer inside the crack simulation module according to the signal.

[0008] In a preferred embodiment, the crack sealing layer real-time monitoring device further comprises a computer module connected to the modulation and demodulation module for recording pressure data.

[0009] In a preferred embodiment, a piston is provided inside the storage container to divide the internal space of the storage container into a first cavity and a second cavity, the pressure pump is connected to the second cavity to pressurize the second cavity, a plugging liquid is provided in the first cavity, and the outlet of the first cavity is connected to the crack simulation module through a connecting pipe.

[0010] In a preferred embodiment, the inner diameter of the communicating pipe is greater than or equal to the outlet diameter.

[0011] In a preferred embodiment, the optical fiber module is in a straight state inside the crack simulation module.

[0012] In a preferred embodiment, the crack simulation module further includes a first bracket and a second bracket, wherein the first bracket and the second bracket are respectively disposed at two ends of the optical fiber module and fixedly connect the two ends of the optical fiber module to the crack simulation module.

[0013] In a preferred embodiment, the first bracket and the second bracket are constructed into the same structure, the first bracket includes a circular frame and two support rods arranged inside the circular frame and connected to the inner wall of the circular frame at both ends, the two support rods cross to form an intersection, the first end of the optical fiber module is fixed to the intersection of the first bracket and the second end of the optical fiber module is fixed to the intersection of the second bracket.

[0014] In a preferred embodiment, the computer module is connected to the pressure pump for controlling the start and stop of the pressure pump.

[0015] In a preferred embodiment, the real-time monitoring device for the crack sealing layer also includes a heating module for heating the crack simulation module, the optical fiber module is used to monitor the temperature changes in the crack simulation module in real time and transmit the signals to the modulation and demodulation module, and the modulation and demodulation module is used to present the distribution of the sealing layer in the crack simulation module according to the signals.

[0016] The present invention also provides a method for real-time monitoring of a crack plugging layer using the aforementioned real-time monitoring device for crack plugging layers, comprising: S1, connecting an optical fiber module to the interior of a crack simulation module, and connecting the optical fiber module to a modulation and demodulation module; S2, determining a formula of a plugging liquid according to the width of a crack plate causing leakage inside the crack simulation module and preparing the plugging liquid; S3, pressing a piston of a storage container to the bottom of a second cavity, and filling the first cavity with the plugging liquid, connecting the pressure pump to the second cavity through a pipeline, and starting the pressure pump to pump oil into the second cavity until the air above the first cavity is discharged, and then closing the pressure pump, and then connecting the first end of the connecting pipeline to the storage container; The outlet of the first cavity is connected, and the second end of the connecting pipe is connected to the crack simulation module; S4, the pressure change of the crack simulation module is monitored in real time through the optical fiber module, the modulation and demodulation module is started, and the fluid pressure distribution in the crack simulation module is measured; S5, the pressure pump is continued to be started to pump the plugging liquid into the crack simulation module at a constant pressure until the pressure is stable, and the pressure distribution in the crack simulation module measured by the optical fiber module is observed; S6, the pressure injection program of the pressure pump is changed, the fluid injection pressure is increased step by step, and the pressure is stabilized for 1 to 10 minutes after each pressure increase, and the pressure distribution change in the crack simulation module measured by the optical fiber module is observed.

[0017] In a preferred embodiment, the real-time monitoring method for the fracture plugging layer further includes turning on the heating module each time the final position of the plugging layer under different fluid pressures is determined, and monitoring the temperature changes at different positions in the fracture simulation module through the optical fiber module.

[0018] The present invention comprises an optical fiber module, a modulation and demodulation module connected to the optical fiber module, a storage container with plugging liquid inside, a pressure pump connected to the storage container, and a fracture simulation module connected to the storage container and having fracture slit plates inside. The pressure pump pressurizes the plugging liquid in the storage container and drives it to flow out between the fracture slit plates to form a plugging layer. The optical fiber module is arranged inside the fracture simulation module and is used to monitor the pressure change in the fracture simulation module in real time and transmit the signal to the modulation and demodulation module. The modulation and demodulation module is used to present the distribution of the plugging layer in the fracture simulation module according to the signal. The pressure pump pressurizes the plugging liquid in the storage container and allows the plugging liquid to enter the fracture simulation module at high pressure. The actual characteristics of the formation can be simulated. The change in the position where the force suddenly changes is the change in the position of the plugging layer. The optical fiber module can monitor the pressure change between the various seam plates inside the crack simulation module in real time, and can transmit the signal to the modulation and demodulation module. The modulation and demodulation module can present the distribution of the plugging layer between the two crack seam plates in the crack simulation module according to the signal, so as to quickly monitor the change of the position of the plugging layer in real time. The technicians can evaluate the plugging effect of the plugging fluid suitable for different cracks and the instability mechanism of the plugging layer according to the real-time feedback of the change results, and give suggestions for the next step of plugging fluid performance regulation to ensure that the plugging position of the plugging fluid can not only appropriately invade the crack, but also has a high pressure bearing capacity, thereby improving the plugging efficiency of the plugging fluid and improving the plugging success rate.

[0019] The present invention provides a piston inside the storage container to divide the internal space of the storage container into a first cavity and a second cavity, a pressure pump is connected to the second cavity to pressurize the second cavity, a plugging liquid is provided in the first cavity, and the outlet of the first cavity is connected to the crack simulation module through a connecting pipe. The first cavity can be compressed by the piston so that the pressure of the plugging liquid in the first cavity gradually increases, thereby ensuring that the plugging liquid can enter between the two crack seam plates of the crack simulation module in a high-pressure state, and can simulate the distribution of the plugging liquid under a high-pressure environment, thereby realizing real-time monitoring of the position of the plugging layer under a high-pressure environment.

[0020] The present invention further comprises a first bracket and a second bracket through the crack simulation module, and the first bracket and the second bracket are respectively arranged at two ends of the optical fiber module and the two ends of the optical fiber module are fixedly connected to the crack simulation module, so that the two ends of the optical fiber module can be fixed to the crack simulation module through the first bracket and the second bracket, and the distance between the first bracket and the second bracket is preset according to the length of the optical fiber module, so that the optical fiber module is in a straight state in the crack simulation module under the fixing action of the first bracket and the second bracket.

[0021] The present invention has a first bracket and a second bracket that are constructed with the same structure, the first bracket includes a circular frame and two support rods that are arranged inside the circular frame and connected to the inner wall of the circular frame at both ends, the two support rods are crossed to form an intersection, the first end of the optical fiber module is fixed to the intersection of the first bracket and the second end of the optical fiber module is fixed to the intersection of the second bracket. The support rods inside the circular frame can improve the stability of the entire circular frame, prevent the optical fiber module from shaking due to the shaking of the circular frame, and thus improve the accuracy of positioning the sealing layer of the optical fiber module.

[0022] The real-time monitoring method for the crack plugging layer of the present invention monitors the pressure change of the crack simulation module in real time through the optical fiber module during the process of the plugging liquid flowing to the crack seam plates of the crack simulation module, starts the modulation and demodulation module, and measures the fluid pressure distribution in the crack simulation module. It can simulate the fluid pressure distribution when the plugging liquid flows out but no plugging layer is formed, and can provide a reference for actual plugging. In the simulation test, it can serve as a control for the subsequent pressurization test.

[0023] The method for real-time monitoring of the crack plugging layer described in the present invention continues to start the pressure pump to pump plugging liquid into the crack simulation module at a constant pressure until the pressure is stable, observes the pressure distribution in the crack simulation module measured by the optical fiber module, and the position where the fluid pressure in the crack simulation module suddenly changes is the plugging layer position, and starts the pressure pump to pressurize the plugging liquid so that the plugging liquid can form a plugging layer, which can simulate the fluid pressure distribution when the plugging liquid forms a plugging layer, and can provide a reference for actual plugging, ensuring that the plugging position of the plugging liquid can both appropriately invade the crack and have a high pressure-bearing capacity, thereby improving the plugging efficiency of the plugging liquid and the plugging success rate. In the simulation test, it can serve as a control for subsequent step-by-step pressurization tests.

[0024] The method for real-time monitoring of the crack plugging layer of the present invention changes the injection program of the pressure pump and gradually increases the fluid injection pressure, stabilizes the pressure for 1 to 10 minutes after each pressure increase, and simultaneously observes the pressure distribution change in the crack simulation module measured by the optical fiber module. The change in the position of the sudden change in the fluid pressure in the crack simulation module is the change in the position of the plugging layer. The position of the plugging layer formed by the plugging liquid is changed by gradually increasing the pressure, which can simulate the change in the position of the plugging layer formed by plugging liquids of different pressures, and provide a reference for actual plugging, ensuring that the plugging position of the plugging liquid can both appropriately invade the crack and have a high pressure bearing capacity, thereby improving the plugging efficiency of the plugging liquid and improving the plugging success rate. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 The overall structure of the real-time monitoring device for crack sealing layer according to the present invention is schematically shown;

[0026] Figure 2 The overall structure of the first bracket and the second bracket of the crack sealing layer real-time monitoring device according to the present invention is schematically shown.

[0027] In the present application, all drawings are schematic drawings, which are only used to illustrate the principles of the present invention and are not drawn according to the actual scale. DETAILED DESCRIPTION

[0028] like Figure 1 As shown, the real-time monitoring device 100 for the crack plugging layer of the present invention includes: an optical fiber module 4, a modulation and demodulation module 7 electrically connected to the optical fiber module 4, a storage container 2 with a plugging liquid (not shown in the figure) inside, a pressure pump 1 connected to the storage container 2, and a crack simulation module 3 connected to the storage container 2 and having two crack seam plates inside. The pressure pump 1 pressurizes the plugging liquid in the storage container 2 and drives the plugging liquid in the storage container 2 to flow out between the crack seam plates to form a plugging layer (not shown in the figure). The optical fiber module 4 is arranged inside the crack simulation module 3, and is used to monitor the pressure change in the crack simulation module 3 in real time and transmit it to the modulation and demodulation module 7 through a signal. The modulation and demodulation module 7 is used to present the distribution of the plugging layer between the two crack seam plates in the crack simulation module 3 according to the signal.

[0029] The pressure pump 1 increases the pressure of the plugging liquid in the storage container 2 by pressurizing the storage container 2, and drives the plugging liquid to flow out of the storage container 2. The pressurized plugging liquid flowing out of the storage container 2 enters between the two crack seam plates in the crack simulation module 3 and forms a plugging layer. Between the two crack seam plates, the pressure at the position where the plugging liquid forms the plugging layer will be different from the position where the plugging liquid does not flow through, so that the pressure at different positions between each seam plate will change. The position where the fluid pressure between the two crack seam plates in the crack simulation module 3 suddenly changes is the position of the plugging layer, and the change in the position where the fluid pressure suddenly changes is the change in the position of the plugging layer. The optical fiber module 4 can monitor the pressure changes between the various seam plates inside the crack simulation module 3 in real time, and can transmit the signal to the modulation and demodulation module 7. The modulation and demodulation module 7 can present the distribution of the plugging layer between the two crack seam plates in the crack simulation module 3 according to the signal.

[0030] In the present invention, the optical fiber module 4 can be an armored optical fiber, and there is a composite optical fiber in the armored optical fiber, which includes a high-temperature and high-sensitivity single-mode optical fiber, a multimode optical fiber, or a special optical fiber, which can monitor the fluid pressure and temperature changes at different positions in real time. The modulation and demodulation module 7 can be a laser Raman spectroscopy / DAS / DTS composite modulation and demodulation instrument, which includes a laser light source, a signal generator, an optoelectronic / photoacoustic modulator, a circulator, a monochromator, a photodetector, a phase demodulator, a demodulation output recorder and a computer, wherein the laser light source is any one of an Ar ion laser, a Kr ion laser, a He-Ne laser, a Nd-YAG laser, or a diode laser; the wavelength range of the Raman laser light source is 325nm-1064nm; the monochromator can be a single grating, a double grating or a triple grating, a plane holographic grating interferometer is used, a multi-layer silicon-coated CaF2 or Fe2O3-coated CaF2 beam splitter, or a quartz beam splitter and an extended range KBr beam splitter. The photodetector uses a photomultiplier tube, a CCD detector, a Ge or InGaAs detector. The phase demodulator is based on one or a combination of fiber Raman scattering, fiber Brillouin scattering and fiber Rayleigh scattering. Its working principle is based on the above fiber scattering principle. It uses advanced optical time domain reflectometry (OTDR) technology or optical frequency domain reflectometry (OFDR) technology to detect the scattering effect of each section in the distributed optical fiber and demodulate the optical signal therein to characterize the stress, strain and temperature characteristics of the current position. The crack simulation module 3 of the present invention includes two oppositely placed crack slit plates, each of which is replaceable and the size of the leakage channel between the crack slit plates can be adjusted by replacing the crack slit plates.

[0031] The present invention comprises an optical fiber module 4, a modulation and demodulation module 7 connected to the optical fiber module 4, a storage container 2 with plugging liquid inside, a pressure pump 1 connected to the storage container 2, and a fracture simulation module 3 connected to the storage container 2 and having a fracture seam plate inside. The pressure pump 1 pressurizes the plugging liquid in the storage container 2 and drives it to flow out between the fracture seams to form a plugging layer. The optical fiber module 4 is arranged inside the fracture simulation module 3 and is used to monitor the pressure change in the fracture simulation module 3 in real time and transmit the signal to the modulation and demodulation module 7. The modulation and demodulation module 7 is used to present the distribution of the plugging layer in the fracture simulation module 3 according to the signal. The pressure pump 1 pressurizes the plugging liquid in the storage container 2 and allows the plugging liquid to enter the fracture simulation module 3 at high pressure, thereby simulating the actual characteristics of the formation. The change in the position where the fluid pressure suddenly changes is the change in the position of the plugging layer (described in detail later). The optical fiber module 4 can monitor the pressure change between the various seam plates inside the crack simulation module 3 in real time, and can transmit the signal to the modulation and demodulation module 7. The modulation and demodulation module 7 can present the distribution of the plugging layer between the two crack seam plates in the crack simulation module 3 according to the signal, so as to quickly monitor the change in the position of the plugging layer in real time. The technicians can evaluate the plugging effect of the plugging fluid suitable for different cracks and the instability mechanism of the plugging layer according to the real-time feedback change results, and give suggestions for the next step of plugging fluid performance regulation to ensure that the plugging position of the plugging fluid can not only appropriately invade the crack, but also has a high pressure bearing capacity, thereby improving the plugging efficiency of the plugging fluid and improving the plugging success rate.

[0032] In one or more embodiments, the device 100 for real-time monitoring of crack sealing layers of the present invention further comprises a computer module 8 connected to the modulation and demodulation module 7 for recording pressure data. The computer module 8 may be a computer terminal.

[0033] The present invention enables the real-time monitoring device 100 for the crack sealing layer of the present invention to also include a computer module 8 connected to the modulation and demodulation module 7, so as to record and display the monitoring data of the laser Raman spectroscopy / DAS / DTS composite modulation and demodulation module 7 in real time, thereby helping technicians to improve the efficiency of data analysis.

[0034] In one or more embodiments, a piston 23 is provided inside the storage container 2 to divide the internal space of the storage container 2 into a first cavity 21 and a second cavity 22. The first cavity 21 is located above the second cavity 22. The pressure pump 1 is connected to the second cavity 22 for pressurizing the second cavity 22. For example, the pressure pump 1 pumps oil into the second cavity 22. A plugging liquid is provided in the first cavity 21, and the outlet of the first cavity 1 is connected to the fracture simulation module 3 through a connecting pipe s. When the pressure pump 1 pressurizes the second cavity 22, the pressure in the second cavity 22 gradually increases, and the piston 23 moves upward under the pressure in the second cavity 22, thereby compressing the space in the first cavity 21. In this process, the air above the plugging liquid in the first cavity 1 can be discharged first, and the pressure of the plugging liquid gradually increases with the compression of the first cavity 21. Subsequently, the plugging liquid flows from the outlet of the first cavity 1 to the fracture simulation module 3 through the connecting pipe s, thereby ensuring that the plugging liquid can enter between the two fracture plates of the fracture simulation module 3 in a high-pressure state, can simulate the actual characteristics of the formation, and realize real-time monitoring of the position of the plugging layer under a high-pressure environment.

[0035] The present invention provides a piston 23 inside the storage container 2 to divide the internal space of the storage container 2 into a first cavity 21 and a second cavity 22, the pressure pump 1 is connected to the second cavity 22 to pressurize the second cavity 22, and the first cavity 21 is provided with a plugging liquid, and the outlet of the first cavity 1 is connected to the crack simulation module 3 through a connecting pipe s. The first cavity 21 can be compressed by the piston 23 so that the pressure of the plugging liquid in the first cavity 21 gradually increases, thereby ensuring that the plugging liquid can enter between the two crack seam plates of the crack simulation module 3 in a high-pressure state, and can simulate the distribution of the plugging liquid under a high-pressure environment, thereby realizing real-time monitoring of the position of the plugging layer under a high-pressure environment.

[0036] In one or more embodiments, the diameter of the outlet of the first cavity 21 of the storage container 2 is greater than 5 mm.

[0037] In one or more embodiments, the inner diameter of the connecting pipe s is greater than or equal to the diameter of the outlet of the first cavity 1 to ensure that the plugging liquids with different particle size combinations can enter the fracture simulation module 3 through the connecting pipe s.

[0038] In one or more embodiments, the connecting pipe s is connected to the outlet of the first cavity 21 of the storage container 2 and the crack simulation module 3 via a quick connector and a threaded part to ensure good sealing between the connecting pipe s and the outlet of the first cavity 21 of the storage container 2 and the crack simulation module 3.

[0039] In one or more embodiments, the optical fiber module 4 is in a straight state inside the crack simulation module 3, which can facilitate the optical fiber module 4 to locate the position of the sealing layer between two crack seam plates.

[0040] like Figure 2 As shown, in one or more embodiments, the crack simulation module 3 further includes a first bracket 31 and a second bracket 32 ​​, which are respectively disposed at two ends of the optical fiber module 4 and fixedly connect the two ends of the optical fiber module 4 to the crack simulation module 3 .

[0041] The present invention further comprises a first bracket 31 and a second bracket 32 ​​through the crack simulation module 3, and the first bracket 31 and the second bracket 32 ​​are respectively arranged at the two ends of the optical fiber module 4 and the two ends of the optical fiber module 4 are fixedly connected to the crack simulation module 3, so that the two ends of the optical fiber module 4 can be fixed to the crack simulation module 3 through the first bracket 31 and the second bracket 32, and the distance between the first bracket 31 and the second bracket 32 ​​is preset according to the length of the optical fiber module 4, so that the optical fiber module 4 is in a straight state in the crack simulation module 3 under the fixing action of the first bracket 31 and the second bracket 32.

[0042] In one or more embodiments, the first bracket 31 is close to the connecting pipe s relative to the second bracket 32, and the first bracket 31 and the second bracket 32 ​​are constructed into the same structure. Taking the structure of the first bracket 31 as an example, the first bracket 31 includes a circular frame 311 and two support rods 312 arranged inside the circular frame 311 and connected to the inner wall of the circular frame 311 at both ends. The two support rods 312 cross to form an intersection. For example, the angle between the two support rods 312 is less than or equal to 90°. The first end of the optical fiber module 4 is fixed to the intersection of the first bracket 31. The second bracket 32 ​​has the same structure as the first bracket 31, and its structure is no longer described in detail. The second end of the optical fiber module 4 is fixed to the intersection of the second bracket 32. It should be noted that the inner diameter of the circular frame 311 of the first bracket 31 is greater than or equal to the inner diameter of the circular frame of the second bracket 32.

[0043] The present invention is constructed with the first bracket 31 and the second bracket 32 ​​having the same structure, the first bracket 31 includes a circular frame 311 and two support rods 312 arranged inside the circular frame 311 and connected to the inner wall of the circular frame 311 at both ends, the two support rods 312 are crossed to form an intersection, the first end of the optical fiber module 4 is fixed to the intersection of the first bracket 31 and the second end of the optical fiber module 4 is fixed to the intersection of the second bracket 32, the stability of the entire circular frame 311 can be improved by the support rods 312 inside the circular frame 311, and the shaking of the optical fiber module 4 due to the shaking of the circular frame 311 can be prevented, thereby improving the accuracy of positioning the sealing layer of the optical fiber module 4.

[0044] In one or more embodiments, the first bracket 31 of the crack simulation module 3 and the second bracket 32 ​​of the crack simulation module 3 are connected to the crack simulation module 3 through threaded parts, and a rubber ring is set between the first bracket 31 and the crack simulation module 3, and a rubber ring is set between the second bracket 32 ​​and the crack simulation module 3 to ensure the sealing between the first bracket 31, the second bracket 32 ​​and the crack simulation module 3.

[0045] In one or more embodiments, the computer module 8 is connected to the pressure pump 1 to control the start and stop of the pressure pump 1 .

[0046] The present invention is connected to the pressure pump 1 through the computer module 8 to control the opening and closing of the pressure pump 1, which is convenient for automatic control of the pressure pump 1 and improves the efficiency of the simulation experiment.

[0047] In one or more embodiments, the crack plugging layer real-time monitoring device 100 of the present invention further includes a heating module 10 for heating the crack simulation module 3, and the optical fiber module 4 is disposed inside the crack simulation module 3, and is used to monitor the temperature change inside the crack simulation module 3 in real time and transmit the signal to the modulation and demodulation module 7, and the modulation and demodulation module 7 is used to present the distribution of the plugging layer inside the crack simulation module according to the signal. Optionally, the heating module 10 covers the periphery of the crack simulation module 3.

[0048] The present invention further includes a heating module 10 for heating the crack simulation module 3, and the optical fiber module 4 is used to monitor the temperature change in the crack simulation module 3 in real time and transmit the signal to the modulation and demodulation module 7, and the modulation and demodulation module 7 is used to present the distribution of the plugging layer in the crack simulation module according to the signal. When determining the final position of the plugging layer, the heating module 10 is turned on, and the temperature change at different positions between the crack seam plates of the crack simulation module 3 is monitored in real time through the optical fiber module 4. The area whose temperature change trend is different from the main cavity area in the crack simulation module 3 is the plugging layer position, thereby realizing the determination of the distribution position of the plugging layer by the heating module 10, and being able to quickly monitor the change of the plugging layer position in real time. The technicians can evaluate the plugging effect of the plugging liquid suitable for different cracks and the instability mechanism of the plugging layer according to the real-time feedback change results, and give the next step of plugging liquid performance regulation suggestions to ensure that the plugging position of the plugging liquid can not only properly invade the crack, but also has a high pressure bearing capacity, thereby improving the plugging efficiency of the plugging liquid and improving the plugging success rate.

[0049] Based on the above-mentioned crack sealing layer real-time monitoring device 100, the present invention also provides a crack sealing layer real-time monitoring method, including:

[0050] S1, connecting the optical fiber module to the inside of the crack simulation module, and connecting the optical fiber module to the modulation and demodulation module;

[0051] S2, determining the formula of the plugging liquid according to the width of the crack plate causing leakage inside the crack simulation module and preparing the plugging liquid;

[0052] S3, pressing the piston of the storage container to the bottom close to the second cavity, filling the first cavity with plugging liquid, connecting the pressure pump to the second cavity through the pipeline, and starting the pressure pump to pump oil into the second cavity until the air above the first cavity is exhausted, turning off the pressure pump, and then connecting the first end of the connecting pipeline to the outlet of the first cavity of the storage container, and connecting the second end of the connecting pipeline to the crack simulation module;

[0053] S4, monitoring the pressure change of the crack simulation module in real time through the optical fiber module, starting the modulation and demodulation module, and measuring the fluid pressure distribution in the crack simulation module;

[0054] S5, continue to start the pressure pump, pump the plugging liquid into the crack simulation module at a constant pressure until the pressure is stable, and observe the pressure distribution in the crack simulation module measured by the optical fiber module;

[0055] S6. Changing the pressure injection program of the pressure pump, gradually increasing the fluid injection pressure, stabilizing the pressure for 1 to 10 minutes after each pressure increase, and observing the pressure distribution changes in the crack simulation module measured by the optical fiber module.

[0056] Step S1 specifically includes: connecting the two ends of the optical fiber module 4 to the intersection of the first bracket 31 and the second bracket 32 ​​of the crack simulation module 3 respectively, and straightening the optical fiber module 4, then fixing the first bracket 31 of the crack simulation module 3 and the second bracket 32 ​​of the crack simulation module 3 inside the crack simulation module 3, and sealing the connection position with a sealing ring to connect the optical fiber module 4 to the modem module 7, wherein the modem module 7 includes a plurality of ports for connecting the optical fiber input end and the output end.

[0057] Step S2 specifically includes: determining the formula of the plugging liquid according to the width of the crack plate causing leakage inside the crack simulation module 3 and based on the plugging guidance rules, and preparing the plugging liquid.

[0058] Step S3 specifically includes: before the plugging experiment begins, the piston 23 of the storage container 2 is first pressed to the bottom of the second cavity 22, and the first cavity 21 is filled with plugging liquid, and then the storage container 2 is sealed, the pressure pump 1 is connected to the second cavity 22 through a pipeline, and the pressure pump 1 is turned on to pump oil into the second cavity 22 to increase the pressure in the second cavity 22. The piston 23 moves upward under the pressure in the second cavity 22 and compresses the first cavity 21 to increase the pressure in the first cavity 21. In the process of the piston 23 moving upward, the plugging liquid will move upward and be retained in the The air above the first cavity 21 is squeezed out, and when fluid flows out at the outlet of the first cavity 21 of the storage container 2, the pressure pump 1 is turned off to ensure that there is no residual air in the first cavity 21 of the storage container 2 to prevent the residual air from affecting the monitored experimental results. Subsequently, the first end of the connecting pipe s is connected to the outlet of the first cavity 21 of the storage container 2, and the second end of the connecting pipe s is connected to the crack simulation module 3. The plugging liquid in the first cavity 21 of the storage container 2 is in a high-pressure state when the piston 23 moves upward, and flows from the outlet of the first cavity 21 of the storage container 2 to the crack simulation module 3.

[0059] Optionally, each time the final position of the plugging layer under different fluid pressures is determined, the heating module 10 is turned on, and the temperature changes at different positions in the crack simulation module 3 are monitored through the optical fiber module 4. The area where the temperature change trend is different from the main cavity area in the crack simulation module 3 is the position of the plugging layer.

[0060] The present invention turns on the heating module 10 and monitors the temperature changes at different positions through the optical fiber module 4 each time the final position of the plugging layer under different fluid pressures is determined, and the area whose temperature change trend is different from the main cavity area in the crack simulation module 3 is the plugging layer position. The position of the plugging layer can be determined by the temperature change monitored by the optical fiber module 4, and combined with the position of the plugging layer determined by the fluid pressure change, the accuracy of determining the position of the plugging layer can be improved.

[0061] The real-time monitoring method for the crack plugging layer of the present invention monitors the pressure change of the crack simulation module 3 in real time by the optical fiber module 4 during the process of the plugging liquid flowing to the crack seam plates of the crack simulation module 3, starts the modulation and demodulation module 7, and measures the fluid pressure distribution in the crack simulation module 3. It can simulate the fluid pressure distribution when the plugging liquid flows out but no plugging layer is formed, and can provide a reference for actual plugging. In the simulation test, it can serve as a control for the subsequent pressurization test.

[0062] The real-time monitoring method for the crack plugging layer of the present invention continues to start the pressure pump 1 to pump the plugging liquid into the crack simulation module 3 at a constant pressure until the pressure is stable, observes the pressure distribution in the crack simulation module 3 measured by the optical fiber module 4, and the position where the fluid pressure in the crack simulation module 3 suddenly changes is the plugging layer position, and starts the pressure pump 1 to pressurize the plugging liquid so that the plugging liquid can form a plugging layer, which can simulate the fluid pressure distribution when the plugging liquid forms a plugging layer, and can provide a reference for actual plugging, ensuring that the plugging position of the plugging liquid can both appropriately invade the crack and have a high pressure-bearing capacity, thereby improving the plugging efficiency of the plugging liquid and the plugging success rate. In the simulation test, it can serve as a control for subsequent step-by-step pressurization tests.

[0063] The method for real-time monitoring of the crack plugging layer of the present invention changes the injection program of the pressure pump 1 and gradually increases the fluid injection pressure, stabilizes the pressure for 1 to 10 minutes after each pressure increase, and simultaneously observes the pressure distribution change in the crack simulation module 3 measured by the optical fiber module 4. The change in the position of the sudden change in the fluid pressure in the crack simulation module 3 is the change in the position of the plugging layer. By gradually pressurizing, the position of the plugging layer formed by the plugging liquid changes, which can simulate the change in the position of the plugging layer formed by plugging liquids of different pressures, and can provide a reference for actual plugging, ensuring that the plugging position of the plugging liquid can both appropriately invade the crack and have a high pressure-bearing capacity, thereby improving the plugging efficiency of the plugging liquid and improving the plugging success rate.

[0064] The present invention can quickly monitor the changes in the position of the plugging layer in real time. The technical personnel can evaluate the plugging effect of the plugging fluid suitable for different cracks and the instability mechanism of the plugging layer according to the real-time feedback of the change results, and give suggestions for the next step of plugging fluid performance regulation to ensure that the plugging position of the plugging fluid can not only appropriately invade the cracks, but also has a high pressure-bearing capacity, thereby improving the plugging efficiency of the plugging fluid and improving the plugging success rate.

[0065] Although the present invention has been described with reference to preferred embodiments, various modifications may be made thereto and parts thereof may be replaced by equivalents without departing from the scope of the present invention. In particular, the various technical features mentioned in the various embodiments may be combined in any manner as long as there are no structural conflicts. The present invention is not limited to the specific embodiments disclosed herein, but includes all technical solutions falling within the scope of the claims.

Claims

1. A real-time monitoring device for a crack sealing layer, comprising: An optical fiber module, a modulation and demodulation module connected to the optical fiber module, a storage container with a plugging liquid inside, a pressure pump connected to the storage container, and a crack simulation module connected to the storage container and having a crack seam plate inside. The pressure pump pressurizes the plugging liquid in the storage container and drives it to flow out between the crack plates to form a plugging layer. The optical fiber module is arranged inside the crack simulation module to monitor the pressure changes in the crack simulation module in real time and transmit the signal to the modulation and demodulation module. The modulation and demodulation module is used to present the distribution of the plugging layer in the crack simulation module according to the signal.

2. The real-time monitoring device for crack sealing layer according to claim 1, characterized in that: The crack sealing layer real-time monitoring device also includes a computer module connected to the modulation and demodulation module, which is used to record pressure data.

3. The real-time monitoring device for crack sealing layer according to claim 1, characterized in that: A piston is provided inside the storage container to divide the internal space of the storage container into a first cavity and a second cavity. The pressure pump is connected to the second cavity to pressurize the second cavity. A plugging liquid is provided in the first cavity. The outlet of the first cavity is connected to the crack simulation module through a connecting pipe.

4. The real-time monitoring device for crack sealing layer according to claim 3, characterized in that: The inner diameter of the communication pipe is greater than or equal to the outlet diameter.

5. The real-time monitoring device for crack sealing layer according to claim 1, characterized in that: The optical fiber module is in a straight state inside the crack simulation module.

6. The real-time monitoring device for crack sealing layer according to claim 5, characterized in that: The crack simulation module further includes a first bracket and a second bracket. The first bracket and the second bracket are respectively disposed at two ends of the optical fiber module and fixedly connect the two ends of the optical fiber module to the crack simulation module.

7. The real-time monitoring device for crack sealing layer according to claim 6, characterized in that: The first bracket and the second bracket are constructed into the same structure, the first bracket includes a circular frame and two support rods arranged inside the circular frame and connected to the inner wall of the circular frame at both ends, the two support rods cross to form an intersection, the first end of the optical fiber module is fixed to the intersection of the first bracket and the second end of the optical fiber module is fixed to the intersection of the second bracket.

8. The real-time monitoring device for crack sealing layer according to claim 2, characterized in that: The computer module is connected to the pressure pump and is used to control the start and stop of the pressure pump.

9. The real-time monitoring device for crack sealing layer according to claim 1, characterized in that: The real-time monitoring device for the crack sealing layer also includes a heating module for heating the crack simulation module. The optical fiber module is used to monitor the temperature change in the crack simulation module in real time and transmit the signal to the modulation and demodulation module. The modulation and demodulation module is used to present the distribution of the sealing layer in the crack simulation module according to the signal.

10. A method for real-time monitoring of a crack sealing layer using the real-time monitoring device for crack sealing layers according to any one of claims 1 to 9, characterized in that: include: S1, connecting the optical fiber module to the interior of the crack simulation module, and connecting the optical fiber module to the modulation and demodulation module; S2, determining a plugging liquid formula according to the width of the crack plate causing leakage inside the crack simulation module and preparing the plugging liquid; S3, pressing the piston of the storage container to the bottom close to the second cavity, filling the first cavity with plugging liquid, connecting the pressure pump to the second cavity through a pipeline, and starting the pressure pump to pump oil into the second cavity until the air above the first cavity is exhausted, closing the pressure pump, and then connecting the first end of the connecting pipeline to the outlet of the first cavity of the storage container, and connecting the second end of the connecting pipeline to the crack simulation module; S4, monitoring the pressure change of the crack simulation module in real time through the optical fiber module, starting the modulation and demodulation module, and measuring the fluid pressure distribution in the crack simulation module; S5, continue to start the pressure pump, pump the plugging liquid into the crack simulation module at a constant pressure until the pressure is stable, and observe the pressure distribution in the crack simulation module measured by the optical fiber module; S6. Changing the pressure injection program of the pressure pump, gradually increasing the fluid injection pressure, stabilizing the pressure for 1 to 10 minutes after each pressure increase, and observing the pressure distribution changes in the crack simulation module measured by the optical fiber module.

11. The method for real-time monitoring of crack sealing layers according to claim 10, characterized in that: The method also includes starting the heating module each time the final position of the plugging layer under different fluid pressures is determined, and monitoring the temperature changes at different positions in the fracture simulation module through the optical fiber module.

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