Salt cavern building monitoring method, device and equipment and storage medium

Abstract

The invention provides a salt cavern cavity building monitoring method, device and equipment and a storage medium, and the method comprises the steps: carrying out the sonar scanning measurement of a formed salt cavern cavity according to a sonar baseline, and obtaining the sonar reflection intensity data and cavity form data; wherein the sonar base line is obtained through pre-calibration before water injection and cavity construction are carried out on the target rock salt interval; acquiring real-time electromagnetic data of the target rock salt interval based on a wide-area electromagnetic method; according to the real-time electromagnetic data and the original formation resistivity background field data, the dissolution front edge and the dissolution state of the salt cavern cavity are determined; wherein the original formation resistivity background field data is obtained in advance based on a wide-area electromagnetic method before water injection and cavity construction are carried out on the target rock salt interval; and determining the stable state of the cavity form of the salt cavern cavity according to the sonar reflection intensity data, the original stratum resistivity background field data and the real-time electromagnetic data. According to the method, the dissolution front edge and the internal dissolution state of the salt cavern cavity can be determined more accurately.

Description

Technical Field

[0001] This application relates to the field of monitoring technology for salt cavern gas storage facilities, and in particular to a method, apparatus, equipment, and storage medium for monitoring salt cavern cavity formation. Background Technology

[0002] Salt cavern gas storage facilities are large underground cavities constructed within underground salt rock layers using water-soluble extraction technology, used to store natural gas, oil, or other energy products. Salt rock has low permeability, self-healing capabilities, and good mechanical stability, making it an ideal geological medium for constructing energy storage facilities. These salt caverns are typically located hundreds to thousands of meters underground, with volumes reaching hundreds of thousands of cubic meters. However, statistics from the International Energy Agency show that approximately 35% of global gas storage facility accidents originate from uncontrolled cavity boundaries, such as collapses and leaks.

[0003] Therefore, as a key facility for natural gas peak shaving and strategic reserves, the safety of salt cavern gas storage facilities is directly related to the stability of energy supply. The safe and stable operation of salt cavern gas storage facilities relies heavily on advanced monitoring technology; thus, accurate monitoring of the morphology of the salt cavern cavity is crucial. Current technology mainly uses sonar for salt cavern monitoring. While sonar offers high local accuracy, its coverage area is small, and it suffers from dynamic monitoring lag, making it impossible to capture dominant dissolution channels in real time and accurately determine the dissolution front and internal dissolution state of the salt cavern cavity. Summary of the Invention

[0004] This application aims to propose a method, device, equipment, and storage medium for monitoring salt cavern formation, which can more accurately determine the dissolution front and internal dissolution state of the salt cavern.

[0005] The salt cavern cavity monitoring method according to the first aspect of this application includes:

[0006] Based on the sonar baseline, the formed salt cavern cavity is scanned and measured with sonar to obtain sonar reflection intensity data and cavity morphology data; wherein, the sonar baseline is pre-calibrated before water injection to create a cavity in the target rock salt layer; Real-time electromagnetic data of the target rock salt layer is obtained based on the wide-area electromagnetic method. Based on the real-time electromagnetic data and the original formation resistivity background field data, the dissolution front and dissolution state of the salt cavern are determined; wherein, the original formation resistivity background field data is obtained in advance based on the wide-area electromagnetic method before water injection to create a cavity in the target rock salt layer; Based on the sonar reflection intensity data, the original formation resistivity background field data, and the real-time electromagnetic data, the stable state of the cavity morphology of the salt cavern is determined.

[0007] According to some embodiments of this application, the original formation resistivity background field data includes background electric field and initial resistivity, and the real-time electromagnetic data includes real-time electric field and real-time resistivity; The step of determining the dissolution front and dissolution state of the salt cavern based on the real-time electromagnetic data and the original formation resistivity background field data includes: The position of the dissolution front of the salt cavern is determined based on the background electric field and the real-time electric field. Based on the real-time resistivity, the rate of resistivity decrease is calculated, and based on the rate of resistivity decrease, the dissolution state within the salt cavern cavity is determined. Based on the real-time resistivity, the refractory erosion boundary during the dissolution process is determined.

[0008] According to some embodiments of this application, the step of calculating the resistivity decrease rate based on the real-time resistivity and determining the dissolution state within the salt cavern cavity based on the resistivity decrease rate includes: If the rate of decrease in resistivity is less than the first rate value, it is determined that the dissolution state within the salt cavern is normal. If the rate of decrease in resistivity is greater than the second rate value, it is determined that the dissolution state within the salt cavern is abnormal, triggering a danger warning; wherein the second rate value is greater than the first rate value.

[0009] According to some embodiments of this application, determining the insoluble erosion boundary during the dissolution process based on the real-time resistivity includes: When the real-time resistivity is greater than or equal to the first resistivity, it is determined that the insoluble erosion boundary is encountered during the dissolution process; If the real-time resistivity is less than the first resistivity, it is determined that the refractory erosion boundary was not encountered during the dissolution process.

[0010] According to some embodiments of this application, after determining that the sparingly soluble dissolution boundary is encountered during the dissolution process, the salt cavern monitoring method further includes: Trigger encrypted sonar scanning measurements at the location corresponding to the real-time resistivity, and update the sonar reflection intensity data and the cavity morphology data.

[0011] According to some embodiments of this application, determining the stable state of the cavity morphology of the salt cavern based on the sonar reflection intensity data, the original formation resistivity background field data, and the real-time electromagnetic data includes: Based on a pre-acquired comprehensive dissolution rate model, the dissolution rate value is obtained according to the sonar reflection intensity data, the initial resistivity, and the real-time resistivity; wherein, the comprehensive dissolution rate model is established based on resistivity and sonar reflection intensity; If the degree of dissolution is greater than a first threshold, the stability of the cavity morphology of the salt cavern is determined to be abnormal, triggering a hazard warning.

[0012] According to some embodiments of this application, the comprehensive solubility model is constrained by the following expression: ; Where L is the degree of solubility, ρ0 is the initial resistivity, and ρ t Let A be the real-time resistivity, α be the resistivity weighting coefficient, and A be the resistivity. t β is the current sonar reflection amplitude, A0 is the initial sonar reflection amplitude, and β is the sonar weighting coefficient.

[0013] The salt cavern monitoring device according to a second aspect embodiment of this application includes: The first data acquisition module is used to perform sonar scanning measurements on the formed salt cavern cavity based on the sonar baseline, and acquire sonar reflection intensity data and cavity morphology data; wherein, the sonar baseline is pre-calibrated before water injection to create a cavity in the target rock salt layer section; The second data acquisition module is used to acquire real-time electromagnetic data of the target rock salt layer based on the wide-area electromagnetic method. The first determining module is used to determine the dissolution front and dissolution state of the salt cavern cavity based on the real-time electromagnetic data and the original formation resistivity background field data; wherein, the original formation resistivity background field data is obtained in advance based on the wide-area electromagnetic method before water injection to create a cavity in the target rock salt layer. The second determining module is used to determine the stable state of the cavity morphology of the salt cavern based on the sonar reflection intensity data, the original formation resistivity background field data, and the real-time electromagnetic data.

[0014] An electronic device according to a third aspect of this application includes a processor and a memory, the memory storing a program or instructions executable on the processor, the program or instructions being executed by the processor to implement the steps of the salt cavern monitoring method as described in any of the first aspect embodiments above.

[0015] A computer-readable storage medium according to a fourth aspect of this application stores computer-executable instructions for performing the salt cavern monitoring method as described in the first aspect of the present application.

[0016] In this embodiment, by dynamically integrating wide-area electromagnetic method and sonar technology, the data update speed is fast during the monitoring process of wide-area electromagnetic method, which can realize the real-time capture of the dominant dissolution channel. Therefore, the electromagnetic method tracks the dissolution front in real time, and the sonar accurately depicts the morphology of the brine filling area. This fully utilizes the technical advantages of the large monitoring coverage of electromagnetic method and the high local accuracy of sonar, and realizes more accurate determination of the dissolution front and internal dissolution state of salt cavern cavity, and also improves the speed and accuracy of salt cavern cavity construction monitoring.

[0017] Other features and advantages of this application will be set forth in the following description, and will be apparent in part from the description, or may be learned by practicing this application. Attached Figure Description

[0018] The above and / or additional aspects and advantages of this application will become apparent and readily understood from the description of the embodiments taken in conjunction with the following drawings, in which: Figure 1 This is a schematic flowchart of an embodiment of the salt cavern cavity monitoring method of this application; Figure 2 This is a schematic diagram of the original formation electrical profile before cavity creation, according to an embodiment of the salt cavern cavity creation monitoring method of this application; Figure 3 This is a schematic diagram of the longitudinal cavity morphology of an embodiment of the salt cavern cavity monitoring method of this application; Figure 4 This is a schematic diagram of the planar cavity morphology of an embodiment of the salt cavern cavity monitoring method of this application; Figure 5 This is a schematic diagram of the well-transmitter-ground receiver construction of an embodiment of the salt cavern monitoring method of this application; Figure 6 This is a three-dimensional cavity schematic diagram of an embodiment of the salt cavern cavity monitoring method of this application; Figure 7 This is a schematic diagram of an embodiment of the salt cavern monitoring device of this application; Figure 8 This is a schematic diagram of the hardware structure of an embodiment of the electronic device of this application. Detailed Implementation

[0019] The embodiments of this application are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain this application, and should not be construed as limiting this application.

[0020] In the description of this application, the use of terms such as "first," "second," etc., is for the purpose of distinguishing technical features only and should not be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated or the order of the technical features indicated.

[0021] In the description of this application, it should be understood that the orientation descriptions, such as up, down, etc., are based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application.

[0022] In the description of this application, it should be noted that, unless otherwise explicitly defined, terms such as "setup," "installation," and "connection" should be interpreted broadly, and those skilled in the art can reasonably determine the specific meaning of the above terms in this application in conjunction with the specific content of the technical solution.

[0023] The technical solution of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the embodiments described below are some embodiments of this application, not all embodiments.

[0024] To facilitate a better understanding of the solutions in the embodiments of this application, the relevant technologies will be introduced first below.

[0025] Salt cavern underground gas storage facilities are crucial for natural gas peak shaving, strategic reserves, and energy security. Their safe and stable operation relies heavily on advanced monitoring technologies. Sonar and electromagnetic methods, as two mainstream geophysical exploration methods, play complementary roles in monitoring the morphology of salt caverns, assessing their integrity, and detecting surrounding geological structures.

[0026] Salt cavern gas storage facilities are large underground cavities constructed within underground salt rock layers using water-soluble extraction technology. They are used to store natural gas, oil, or other energy products. Salt rock has low permeability, self-healing capabilities, and good mechanical stability, making it an ideal geological medium for constructing energy storage facilities. These salt caverns are typically located hundreds to thousands of meters underground, with volumes reaching hundreds of thousands of cubic meters.

[0027] Therefore, to ensure the safe operation of salt cavern gas storage facilities, continuous monitoring of the following aspects is essential. First, continuous monitoring of changes in the cavity morphology is necessary. During long-term use, salt caverns may undergo morphological changes due to salt rock creep, internal pressure variations, or geological activity, affecting storage capacity and structural safety. Second, continuous monitoring of the cavity integrity is crucial. Preventing natural gas leakage is a core requirement for gas storage facility operation, necessitating monitoring of the sealing of the surrounding rock and the presence of cracks or collapse risks.

[0028] Figure 1This is a schematic flowchart of an embodiment of the salt cavern cavity monitoring method of this application; Figure 2 This is a schematic diagram of the original formation electrical profile before cavity creation, according to an embodiment of the salt cavern cavity creation monitoring method of this application; Figure 3 This is a schematic diagram of the longitudinal cavity morphology of an embodiment of the salt cavern cavity monitoring method of this application; Figure 4 This is a schematic diagram of the planar cavity morphology of an embodiment of the salt cavern cavity monitoring method of this application; Figure 5 This is a schematic diagram of the well-transmitter-ground receiver construction of an embodiment of the salt cavern monitoring method of this application; Figure 6 This is a three-dimensional cavity schematic diagram of an embodiment of the salt cavern cavity monitoring method of this application; Figure 7 This is a schematic diagram of an embodiment of the salt cavern monitoring device of this application; Figure 8 This is a schematic diagram of the hardware structure of an embodiment of the electronic device of this application.

[0029] See below. Figure 1 The embodiments of this application are further described below. This application proposes a method for monitoring a salt cavern cavity, which includes the following steps: Step 101: Based on the sonar baseline, perform sonar scanning measurements on the formed salt cavern cavity to obtain sonar reflection intensity data and cavity morphology data; wherein, the sonar baseline is pre-calibrated before water injection to create a cavity in the target rock salt layer section; Step 102: Based on the wide-area electromagnetic method, obtain real-time electromagnetic data of the target rock salt layer; Step 103: Determine the dissolution front and dissolution state of the salt cavern cavity based on real-time electromagnetic data and original formation resistivity background field data; wherein, the original formation resistivity background field data is obtained in advance based on the wide-area electromagnetic method before water injection to create a cavity in the target rock salt layer. Step 104: Determine the stable state of the cavity morphology of the salt cavern based on sonar reflection intensity data, original formation resistivity background field data, and real-time electromagnetic data.

[0030] In this embodiment, by dynamically integrating wide-area electromagnetic method and sonar technology, the data update speed is fast during the monitoring process of wide-area electromagnetic method, which can realize the real-time capture of the dominant dissolution channel. Therefore, the electromagnetic method tracks the dissolution front in real time, and the sonar accurately depicts the morphology of the brine filling area. This fully utilizes the technical advantages of the large monitoring coverage of electromagnetic method and the high local accuracy of sonar, and realizes more accurate determination of the dissolution front and internal dissolution state of salt cavern cavity, and also improves the speed and accuracy of salt cavern cavity construction monitoring.

[0031] First, it needs to be explained that the entire process of water injection to create cavities in suitable rock strata can be divided into three stages: before cavity creation, during cavity creation, and after cavity creation. Before cavity creation, no water injection is performed, and the rock salt strata remain unchanged. During cavity creation, water is injected into the target rock salt strata using an artificial water injection process. The fresh water dissolves the salt, eroding easily soluble areas and forming cavities. This measure is called "cavity creation." During this stage, the rate of water dissolution and the cavity boundaries need to be monitored and evaluated in real time to ensure process safety and the effectiveness of the water injection dissolution measures. The salt cavern cavity creation monitoring method in this application is conducted during the water injection cavity creation process. After cavity creation, the stability of the cavity boundaries needs to be periodically tested to ensure that changes in the cavity boundaries are controllable and the range of change is acceptable, laying the foundation for the later use of the cavity. This application explores the application of a fusion of wide-area electromagnetic methods and sonar scanning technology in the salt cavern cavity creation process.

[0032] The aforementioned sonar baseline was pre-calibrated before water injection to create a cavity in the target rock salt layer. The original formation resistivity background field data was pre-acquired based on the wide-area electromagnetic method before water injection to create a cavity in the target rock salt layer.

[0033] Understandably, before water injection to create a cavity, it is necessary to measure the initial state of the strata, including the acquisition of the wide-area electromagnetic background field and the calibration of the sonar baseline.

[0034] Sonar baseline calibration is a mature technology. In salt cavern sonar measurements, the concept of "sonar baseline" is mainly reflected in the following two aspects.

[0035] The first is the "spatial baseline" used as a measurement reference. When a sonar instrument takes measurements, it uses a fixed imaginary reference surface or line (such as the instrument's central axis) as a spatial reference, emitting sound waves in all directions and measuring the distance to the cavity walls. All measured distances are calculated from this "baseline." However, it should be noted that modern advanced sonar systems can achieve 360° horizontal rotation and 90° vertical swing arm movement for all-around scanning, thereby more accurately constructing the three-dimensional shape of the cavity and reducing errors caused by the simple spatial baseline assumption.

[0036] The second is the "time baseline" or "zero-point correction" that serves as the starting point for the calculation; this is a more common and crucial meaning. Salt cavern sonar measurements essentially determine distance by calculating the round-trip time of sound waves, and its core formula is: d = (v×t) / 2; Where d is the distance from the probe to the cavity wall, v is the actual propagation speed of the sound wave in the downhole medium (such as brine or natural gas), and t is the round-trip time of the sound wave from transmission to reception. Therefore, knowing the accurate sound speed v is crucial for calculating the distance d. However, the sound speed v is not constant; it is significantly affected by downhole temperature, pressure, and the composition of the medium. In a sonar system, the "time baseline" defines the start and end positions of the ultrasonic signal on the time axis, which is related to whether the system can accurately capture and resolve the echo signal. More importantly, in actual measurements, the system needs to determine a "zero point" for time calculation. This zero point may be affected by factors such as circuit delays and transducer response. Therefore, before formal measurement, it is often necessary to determine an accurate "time baseline" through calibration, or to use special methods, such as the "double echo method" mentioned below, to eliminate errors caused by these system delays and ensure accurate time measurement. This process is sometimes called "zero-point correction."

[0037] Specifically, since the speed of sound has a huge impact on the measurement results and it changes with the environment, directly using an empirical value, such as setting the speed of sound to 1800 m / s in brine and 400 m / s in natural gas, will introduce errors. Therefore, in high-precision salt cavern measurement chambers, some techniques are used to acquire or calibrate the speed of sound in real time, such as the double echo method for measuring the speed of sound and the double depth method for calculating the speed of sound.

[0038] The dual-echo method for measuring sound velocity involves installing a sound velocity measurement section with a specific reflector (such as a semi-circular baffle) on the instrument. After the sonar probe emits a sound wave, it receives reflected echoes from two different distances. By calculating the path difference and time difference between these two echoes, the actual sound velocity under the given conditions can be accurately calculated. Since the two echoes experience the same system delay, subtracting them eliminates the effect of the delay, thus achieving high-precision measurement of sound velocity.

[0039] The dual-depth method for calculating sound velocity is another approach. By measuring the distance from the probe to the bottom of the salt cave at two different depths (H1 and H2), assuming that the sound velocity v is the same at these two similar depths, the true sound velocity v can be calculated using the formula v=2×(H2-H1) / (t2-t1), where t1 and t2 are the round-trip times of the sound wave obtained from the two measurements. This method also reduces the dependence on empirical sound velocity values.

[0040] In some cases, during sonar baseline calibration, a rotating sonar probe is typically lowered into the well to the initial depth of the cavity (usually 5m below the casing shoe) to measure the initial wellbore diameter, generally using a φ244.5mm casing. Before lowering the probe, the transmission frequency is calibrated to 200kHz, a value that balances penetration and resolution; the sampling interval is 2mm (axial) × 5° (circumferential); and the scanning speed is 15rpm, meaning one revolution is completed every 4 seconds.

[0041] During the cavity-making process, high-pressure, low-mineralization fracturing fluid is injected into the low-resistivity rock-salt layer through the wellbore. After the rock-salt layer is broken open, the low-mineralization fresh water dissolves the salt, reducing the mineralization and rock structure strength of the target layer, thereby achieving the effect of dissolution and cavity formation. Therefore, during the cavity-making process, it is necessary to monitor the cavity-making effect and the boundary dissolution range in real time.

[0042] This process can primarily utilize sonar cavity measurement technology to monitor the cavity creation effect, i.e., measuring the cavity morphology and determining whether the cavity has reached the expected position and whether the cavity boundary is clear. Wide-area electromagnetic technology is used as an anomaly monitoring technology to assist in monitoring the cavity creation effect. Specifically, wide-area electromagnetic technology can detect the rate of decrease in apparent resistivity to determine whether there are signs of continued outward expansion of the cavity boundary. Generally speaking, the cavity boundary is the boundary between easily soluble salt rock and insoluble rock, but it is not guaranteed that the insoluble rock will not be dissolved under the flushing of the cavity creation fluid or long-term immersion in the injected fluid later. Therefore, the rate of decrease in apparent resistivity is used for monitoring.

[0043] Based on the sonar baseline, sonar scanning measurements are performed on the formed salt cavern cavities to obtain sonar reflection intensity data and cavity morphology data. This utilizes sonar cavity measurement technology. Specifically, a 360° scan of the cavity is performed every 15 minutes. The specific interval depends on the injection volume, dissolution rate, and formation porosity connectivity. Typically, the scanning interval is 15 minutes in normal dissolution sections, but can be reduced to 5 minutes in abnormal sections, or even continuous scanning can be achieved.

[0044] The scanning angle interval is 5°, and in some geologically anomalous areas, the interval can be increased to achieve a precision of 0.1° for detailed measurements. The longitudinal descent rate of the probe is 0.5 m / min.

[0045] In the aforementioned sonar cavity measurement technique, the measured parameters include radial distance and top plate subsidence. The accuracy of the radial distance is within ±2cm, and the accuracy of the top plate subsidence is within ±5cm. This results in longitudinal cavity morphology and planar cavity morphology diagrams, as detailed below. Figure 3 and Figure 4 As shown.

[0046] Wide-area electromagnetic (WEMA) is a mature technology that utilizes a WEMA transmitting system and a matching receiving system to collect electromagnetic data. Typically, electromagnetic waves of a certain frequency are transmitted from the ground at a distance, and a receiving system is deployed in the study area to collect and receive the data. In this case, the formation resistivity requires a series of algorithmic processing steps, which is quite cumbersome and suitable for data collection from deep, complete formations. However, this application uses it in a salt cavern cavity construction scenario. Since the cavity construction process is based on a well, moving the WEMA transmitter to the well provides greater realism. Specifically, it employs a "well-based transmission - ground-based reception" method, as detailed below. Figure 5 As shown.

[0047] The aforementioned raw formation resistivity background field data was collected before cavity creation using the wide-area electromagnetic method, while the aforementioned real-time electromagnetic data was collected in real time during the cavity creation process.

[0048] Specifically, the wide-area electromagnetic background field is acquired using a "wellbore-to-surface" method to obtain the original formation resistivity. This involves supplying a specific frequency of alternating current through the wellbore, where the wellbore and low-resistivity cavity-building fluid form an integrated underground conductor. Measuring points are deployed on the cavity-building surface to obtain the original formation resistivity. Depth calibration is then performed using specific electrical strata to identify high-resistivity interlayers, resulting in the original formation electrical profile before cavity construction. For example... Figure 2 As shown.

[0049] The above-mentioned wide-area apparent resistivity data can be calculated using the following formula:

[0050] Among them, E x Let x be the electric field component of the wide-area electromagnetic device, MN be the distance between adjacent receiving points of the wide-area electromagnetic device, I be the magnitude of the harmonic current transmitted by the wide-area electromagnetic device, K be the device coefficient of the observation device of the wide-area electromagnetic device, which is only related to the transmission parameters, and F(ikr) be the electromagnetic effect coefficient, which contains information about the transmission frequency.

[0051] The aforementioned device coefficient K can be obtained using the following formula:

[0052] Where dL is the distance of the electric dipole source of the wide-area electromagnetic device, and r is the transmit / receive distance of the wide-area electromagnetic device.

[0053] The electromagnetic effect coefficient F(ikr) mentioned above can be obtained by the following formula:

[0054] in, θ is the azimuth angle, r is the transmit / receive distance of the wide-area electromagnetic device; k is the wave number, and i is the imaginary unit.

[0055] The identification of specific electrical resistivity layers mentioned above is performed using well logging data. Layers showing low values ​​on the well logging resistivity curve, if also showing low natural gamma values, are considered sandstone. This is generally attributed to the high water saturation, high formation mineralization, and high ion concentration of the sandstone, resulting in low formation resistivity. Conversely, if the natural gamma value is also high, it is generally identified as a low-resistivity shale layer. In areas with high logging resistivity, the influence of hydrocarbons needs to be excluded, and the lithology of the high-resistivity section needs to be comprehensively identified, such as igneous rocks. High-resistivity igneous rocks or low-resistivity shale are usually considered specific electrical resistivity layers. Because well logging data accurately determines the top and bottom depths of formations, using well logging data for depth correction of each formation is feasible and a commonly used method.

[0056] The transmission frequency of the aforementioned wide-area electromagnetic system is typically set based on the depth. The cavity depth is generally within 2000m, therefore the selected wide-area electromagnetic frequency range is between 0.1Hz and 100Hz. Specific transmission frequency parameters can be adjusted according to actual conditions to ensure they meet specific monitoring requirements; the transmission current is typically greater than 50A.

[0057] Understandably, the signal transmitter in a wide-area electromagnetic transmission system is located inside the well, typically 1-3 kilometers from the wellhead, depending on the well depth. The supporting receiving system comprises multiple receiving points positioned on the ground within a certain range near the wellhead. Therefore, by combining data from all these points, the corresponding wide-area resistivity at various points within a certain range near the wellhead can be determined. Furthermore, to ensure data synchronization, all supporting receiving systems use GPS or BeiDou satellites for time synchronization, achieving an accuracy down to the μs level.

[0058] In some implementations, the raw formation resistivity background field data includes the background electric field and the initial resistivity, and the real-time electromagnetic data includes the real-time electric field and the real-time resistivity. Based on real-time electromagnetic data and raw formation resistivity background field data, the dissolution front and dissolution state of the salt cavern were determined, including: The location of the dissolution front of the salt cavern cavity was determined based on the background electric field and the real-time electric field. Based on the real-time resistivity, the rate of resistivity decrease is calculated, and based on the rate of resistivity decrease, the dissolution state within the salt cavern cavity is determined. The boundary of refractory erosion during the dissolution process is determined based on the real-time resistivity.

[0059] In this embodiment, based on the wide-area electromagnetic method, the changes in electric field and real-time resistivity can be determined, thereby enabling the monitoring of the dissolution front and dissolution state of the salt cavern.

[0060] The above method determines the dissolution front position of the salt cavern cavity based on the background electric field and the real-time electric field. Specifically, the background electric field measured before cavity creation can be denoted as U0(M), and the real-time electric field measured during cavity creation can be denoted as U. t (M), the time domain difference between these two electric fields is divided into U0(M)-U t (M) It is understandable that as the cavity-forming fluid dissolves continuously during the cavity-forming process, the cavity changes along with the electric field. Therefore, by using the data difference in the electric field time domain, the leading edge position of the cavity-forming fluid can be accurately monitored.

[0061] The above calculation of the resistivity decrease rate based on real-time resistivity, and the determination of the dissolution state within the salt cavern cavity based on the resistivity decrease rate, can be understood as follows: when water is injected to dissolve the salt rock, the resistivity of the brine zone will obviously be less than that of the salt rock portion. Under normal conditions, a uniform dissolution process should result in a steady decrease in resistivity. Therefore, the resistivity decrease rate can be calculated based on the continuously measured real-time resistivity, and the dissolution process can be judged based on the resistivity decrease rate to determine whether the dissolution process is normal and whether there is a dangerous situation of dissolution being too rapid.

[0062] The above method of determining the insoluble dissolution boundary during the dissolution process based on real-time resistivity can be understood as follows: when encountering an insoluble dissolution boundary, i.e., encountering a high-resistivity stratum, such as an anhydrite interlayer, dissolution cannot continue, and the real-time resistivity measured for the high-resistivity stratum will quickly rise back to a higher value. Therefore, it is possible to determine whether an insoluble dissolution boundary is encountered during the dissolution process based on real-time resistivity, and to determine whether the cavity-building process will reach the cavity boundary.

[0063] In some implementations, the resistivity decrease rate is calculated based on the real-time resistivity, and the dissolution state within the salt cavern is determined based on the resistivity decrease rate, including: If the rate of decrease in resistivity is less than the first rate value, it is determined that the dissolution state within the salt cavern is normal. If the rate of decrease in resistivity is greater than the second rate value, it is determined that the dissolution state within the salt cavern is abnormal, triggering a danger warning; wherein, the second rate value is greater than the first rate value.

[0064] In this embodiment, the first rate value and the second rate value can be predetermined according to the actual situation. By comparing the resistivity decrease rate with the threshold, the dissolution state in the salt cavern cavity can be determined more precisely.

[0065] Specifically, the resistivity of high-concentration brine (i.e., near-saturated brine) is typically less than 0.5 Ω·m. In some cases, when water is injected to dissolve the salt rock, the resistivity of the brine zone drops sharply to 0.5-2 Ω·m. By monitoring the rate of decrease in apparent resistivity (dρ / dt) in real time using wide-area electromagnetic methods, the dissolution state within the salt cavern cavity can be determined. The first rate value can be set to 0.1, and the second rate value can be set to 0.5. The above process is specifically limited by the following expression:

[0066] Specifically, when the apparent resistivity decreases at a rate less than 0.1 Ω·m / h, the cavity-forming fluid is considered to be uniformly dissolved; when the apparent resistivity decreases at a rate greater than 0.5 Ω·m / h, preferential dissolution channels exist in the target layer, requiring measures such as reducing the cavity-forming fluid flow rate and increasing viscosity to mitigate the risk of collapse; when the apparent resistivity decreases at a rate between 0.1 and 0.5 Ω·m / h, attention is required, and preventative measures and contingency plans should be implemented. It is understandable that a lower second rate value results in greater sensitivity to resistivity changes and can be adjusted according to actual needs.

[0067] In some implementations, the insoluble erosion boundary during the dissolution process is determined based on real-time resistivity, including: When the real-time resistivity is greater than or equal to the first resistivity, the insoluble corrosion boundary encountered during the dissolution process is determined. When the real-time resistivity is less than the first resistivity, it is determined that no insoluble corrosion boundary was encountered during the dissolution process.

[0068] In this embodiment, the threshold of the first resistivity can be predetermined according to the actual situation. By comparing the real-time resistivity with the threshold, the boundary of the refractory erosion during the dissolution process can be determined more precisely.

[0069] Specifically, the first resistivity can be set to 20 Ω·m. That is, when the apparent resistivity suddenly rises to greater than or equal to 20 Ω·m, it means that at the location corresponding to the real-time resistivity, in the direction of dissolution outward from the wellhead, a refractory dissolution boundary is encountered, which will most likely become the boundary of the salt cavern after it finally stabilizes.

[0070] In some implementations, after identifying the insoluble dissolution boundary encountered during the dissolution process, the salt cavern monitoring method further includes: Trigger encrypted sonar scanning measurements at the location corresponding to the real-time resistivity, and update the sonar reflection intensity data and cavity morphology data.

[0071] In this embodiment, by using a wide-area solenoid valve, when encountering a difficult-to-dissolve boundary, a more detailed and accurate solenoid reflection intensity data and cavity morphology data can be obtained by triggering a dense solenoid scan measurement at the corresponding position of real-time resistivity.

[0072] Understandably, during the salt cavern creation process, a preliminary scan was first performed using sonar technology to obtain initial sonar reflection intensity data and cavity morphology data. Simultaneously, real-time resistivity was obtained using wide-area electromagnetic methods. Real-time changes in resistivity enable dynamic monitoring of the cavity's dissolution front position and cavity boundaries, resulting in faster data updates and lower costs compared to sonar technology. Once the location and direction of the refractory erosion boundary encountered during the dissolution process are determined, a more detailed sonar scan is performed within a small area. For example, the scanning angle interval is 10° in other areas, while a fine measurement with a scanning angle interval of 2° is performed in the area where the refractory erosion boundary is encountered. This achieves efficient, accurate, and low-cost acquisition of the latest cavity measurement data.

[0073] In some implementations, the stable state of the salt cavern morphology is determined based on sonar reflection intensity data, raw formation resistivity background field data, and real-time electromagnetic data, including: Based on a pre-acquired comprehensive dissolution rate model, the dissolution rate value is obtained according to sonar reflection intensity data, initial resistivity, and real-time resistivity; wherein, the comprehensive dissolution rate model is established based on resistivity and sonar reflection intensity; If the degree of solubility exceeds the first threshold, the stability of the cavity morphology of the salt cavern is determined to be abnormal, triggering a hazard warning.

[0074] In this embodiment, during the cavity creation stage, a model is jointly established based on wide-area apparent resistivity data and sonar reflection intensity to determine the same stable state of the cavity. This enables data fusion control and reduces misjudgments caused by single data anomalies.

[0075] In some implementations, the comprehensive solubility model is constrained by the following expression: ; Where L is the degree of solubility, ρ0 is the initial resistivity, and ρ t For real-time resistivity, α is the resistivity weighting coefficient, and A t β is the current sonar reflection amplitude, A0 is the initial sonar reflection amplitude, and β is the sonar weighting coefficient.

[0076] In this embodiment, a specific expression for the comprehensive solubility model is disclosed. In the above formula, ρ0 is the initial resistivity, with units of Ω·m, and ρ t This refers to the real-time resistivity, i.e., the apparent resistivity over a wide area at the current moment, expressed in Ω·m (A). tThe current sonar reflection amplitude is usually measured by target strength (TS) in decibels (dB). A0 is the initial sonar reflection amplitude. α and β are resistivity and sonar weighting coefficients, which can be adjusted between 0.2 and 0.5 according to the actual situation. L is a custom solubility value defined in this application. Its specific value is affected by changes in resistivity and sonar data. The larger the L value, the greater the fluctuation in resistivity and sonar data, and the more unstable the cavity morphology. The first threshold is used to judge the value of L. The selection of the first threshold needs to be determined according to the actual situation.

[0077] To better understand the above comprehensive solubility model, an implementation method is proposed below for detailed explanation.

[0078] When the monitored object is a typical layered salt cave, the lithological profile of its cavity-forming section can be divided into three layers from top to bottom: (1) Upper salt rock layer: easily soluble, with high purity, and is the main target layer for cavity formation. (2) Middle anhydrite interlayer: difficult to dissolve, with high resistivity, and is the key layer affecting the stability of the cavity shape. (3) Lower salt rock layer: easily soluble, with properties similar to the upper salt rock layer.

[0079] During cavity construction, fresh water is injected to dissolve the salt rock, forming the cavity. By detecting the L value, the normality of the cavity morphology can be monitored in real time, paying particular attention to whether the anhydrite interlayer is uniformly dissolved, and whether there is a risk of localized rapid dissolution (dominant channels) or insufficient dissolution.

[0080] α is the weighting coefficient for the change in apparent resistivity over a wide area, reflecting the importance of resistivity change (i.e., degree of dissolution) in the comprehensive criterion. β is the weighting coefficient for the change in sonar reflection intensity, reflecting the importance of cavity wall morphology (characterized by acoustic wave reflection intensity) in the comprehensive criterion.

[0081] Regarding the values ​​of α and β, firstly, considering balance, although the sum of the weighting coefficients α + β is not fixed at 1, each is set within the range of 0.2-0.5. This avoids a single parameter dominating the judgment and ensures that resistivity and sonar data are considered in a balanced manner. Secondly, considering flexibility, the range of 0.2-0.5 allows for dynamic adjustment based on actual geological conditions and monitoring stages. For example, in easily soluble pure salt rock layers, α can be appropriately increased, such as to 0.4, relying more on resistivity changes to indicate dissolution. In complex sections with anhydrite interlayers, β can be increased, such as to 0.45, relying more on direct sonar detection of morphological changes. Finally, for default values, it is recommended that in practical applications, if there are no special geological anomalies, the default value for both α and β be set to 0.3. This is a relatively neutral and balanced starting point, indicating that resistivity changes and sonar reflection intensity changes are given equally important initial weights when judging cavity morphology. Users can fine-tune this based on feedback from subsequent monitoring data.

[0082] Taking default values ​​α=0.3, β=0.3, and a first threshold of 1.5 as an example, the dissolution degree value L>1.5 is used as the warning threshold for abnormal cavity morphology. The following describes common scenarios during cavity creation.

[0083] In a normal, homogeneous dissolution scenario, assuming the apparent resistivity decreases uniformly from 25 Ω·m to 20 Ω·m, the reflection intensity slightly increases. Due to the smoother cavity walls, the resistivity change is as follows: = = 0.2 The change in sonar reflection intensity is shown in the following formula: = 1.1 Therefore, the calculated value of L is shown in the following formula: L = 0.3 × 0.2 × 0.3 × 1.1 = 0.0198 Therefore, since the L value is much lower than 1.5, the system judges it as normal dissolution.

[0084] In scenarios of abnormally rapid dissolution (with a dominant dissolution channel), assuming a sharp decrease in apparent resistivity from 25 Ω·m to 8 Ω·m, the reflection intensity weakens, possibly due to irregularities or depressions in the cavity walls. In this case, the resistivity change is as follows: = = 0.68 The change in sonar reflection intensity is shown in the following formula: = 0.7 Therefore, the calculated value of L is shown in the following formula: L= 0.3×0.68×0.3×0.7≈0.043 Therefore, if the L value is below 1.5, the system judges it as a normal state, not yet reaching the level of a stable cavity morphology abnormality that requires triggering a danger warning. It should be noted that although the above L value is still not high, it should be observed that abnormal L values ​​are usually dominated by a drastic change in one of the parameters.

[0085] For example, if the resistivity drops sharply while the sonar detects a significant decrease in local reflection intensity ( = 0.5), then L = 0.3 × 0.68 × 0.3 × 0.5 ≈ 0.031. Although the absolute value is not large, its trend and combination pattern will trigger the algorithm's attention.

[0086] Regarding the L threshold, L = 1.5 is a relatively high threshold, meaning that both resistivity and sonar reflection intensity need to show very significant changes simultaneously. For example, a combination of resistivity decreasing by more than 70% and reflection intensity changing by more than 50% might be sufficient after weighting adjustments. This helps reduce false alarms, triggering an alert only when a truly significant anomaly is detected. However, it also increases the risk of missed alarms, so in some cases, the L alert value needs to be lowered.

[0087] In some implementations, in order to ensure the sensitivity of the early warning, L is finely divided and the early warning value of L is adjusted, as shown in Table 1 below.

[0088]

[0089] Table 1 Classification Table for L Values In some cases, with α=β=0.3, the resistivity change in scenarios where early preferential dissolution channels form is as shown in the following equation: = = 0.12 The above formula shows that the resistivity change has shown an initial abnormal downward trend; The change in sonar reflection intensity is shown in the following formula: = 0.85 The above equation shows that the reflection intensity decreases as the cavity wall begins to become irregular; Therefore, the calculated value of L is shown in the following formula: L=(0.3×0.12)×(0.3×0.85)= 0.036×0.255≈0.0092 Although the L value seems small, its dynamic trend is crucial. If the L value rises continuously from 0.001 to 0.3 in a short period of time, its growth rate and absolute value are signals that require close attention. Therefore, the system monitors not only the absolute value of L, but also its trajectory of change.

[0090] In some implementations, after determining whether the cavity morphology of the salt cavern is normal based on sonar reflection intensity data, original formation resistivity background field data, and real-time electromagnetic data, the salt cavern cavity creation monitoring method further includes: After the target rock salt layer is filled with water to create a cavity, a three-dimensional cavity model is established based on the cavity morphology data to obtain the cavity volume of the salt cavern formed after the cavity is created. The salt cavern cavity is filled with brine according to its volume; Based on the wide-area electromagnetic method, the boundary formation resistivity of the salt cavern cavity boundary is obtained; The airtightness of the salt cavern cavity was verified based on the resistivity of the boundary strata.

[0091] In this embodiment, the evaluation step is performed on the cavity after cavity construction. It is necessary to monitor the cavity boundary to ensure that the boundary is clear, without leakage or collapse. By using wide-area electromagnetic method for dynamic monitoring, the sealing performance and safety of the cavity are judged, which helps the safe operation of the subsequent salt cavern gas storage.

[0092] The above describes the establishment of a three-dimensional cavity model based on cavity morphology data. This involves using sonar data to create a three-dimensional cavity model, and inferring the three-dimensional spatial position of the cavity boundaries through longitudinal and transverse morphological diagrams, thus forming a highly reliable three-dimensional cavity model. Specifically, as follows... Figure 6 As shown, the input cavity model has a longitudinal resolution of less than 0.1m, and the error between the output cavity volume and the actual injected cavity fluid volume is less than 1%.

[0093] The aforementioned method of filling the salt cavern cavity with brine can be achieved by injecting high-mineralization brine with a resistivity of less than 1 Ω·m. It is understood that the volume of the injected brine is consistent with the volume of the cavity.

[0094] In some implementations, the cavity sealing performance is verified based on the boundary formation resistivity, including: If the rate of decrease in resistivity of the boundary formation within a preset lateral length range is greater than or equal to the second threshold, it is determined that the salt cavern cavity has poor sealing performance and that there is crack leakage at the corresponding location.

[0095] In this embodiment, the rate of decrease in the resistivity of the boundary formation within a preset lateral length range represents the situation where, if high-salinity brine permeates through the boundary of the cavity, the resistivity of the formation outside the cavity will decrease when viewed from the same depth plane. In reality, this is due to the presence of cracks causing lateral outward diffusion.

[0096] The aforementioned second threshold is typically between 5% and 10%, and in some cases, it can be set to 1%. The setting of the second threshold is determined based on the accuracy, i.e., the sensitivity, required by the client. However, it should be noted that a second threshold set to 1% may be affected by local data distortion, fluctuations, or errors, and is generally not set to 1%.

[0097] The aforementioned preset lateral length range is also determined based on the client's requirements. In some cases, it is acceptable for the fluid inside the cavity to diffuse outward from the cavity boundary to a range of less than 100m; in other cases, a diffusion range of less than 50m is considered acceptable.

[0098] Specifically, the second threshold can be set to 10%. If the resistivity of the formation at the cavity boundary (50-100m) decreases by 10% or more, it is considered that there is a crack and leakage at that location, and artificial treatment is required. If the resistivity of the formation at the cavity boundary (50-100m) is stable and the resistivity fluctuation is less than 10%, it is considered that the cavity has good sealing performance.

[0099] In some implementations, existing salt cavern monitoring technologies suffer from three major drawbacks: First, a detection blind zone—sonar cannot detect the unfilled dissolution front, which occupies 40% of the cavity's expansion phase, while electromagnetic methods struggle to identify thin interlayers <5m, such as hard gypsum layers; second, a contradiction between accuracy and range—sonar offers high local accuracy but has a small coverage area, while electromagnetic methods have a large range but low vertical resolution; and third, dynamic monitoring is lagging—existing systems have a data update cycle >1 hour, making it impossible to capture the dominant dissolution channel in real time. To address these issues, this application proposes a wide-area electromagnetic method and sonar dynamic fusion technology. This technology uses electromagnetic methods to track the dissolution front in real time and sonar to accurately characterize the morphology of the brine-filled zone, establishing a resistivity-sonar reflection intensity correlation model to achieve full-space coverage and multi-parameter coordination. Simultaneously, by employing GPS / BeiDou dual-mode synchronization and adaptive scanning strategies, the anomaly response time is reduced from 1 hour to 5 minutes, the accuracy of dissolution front prediction is increased from 40% to 70%, and the cavity volume calculation error is reduced to ±0.8%. This technology can reduce the cavity construction cycle by 21%, significantly improving safety and economy.

[0100] In some embodiments, this application represents the first fusion of wide-area electromagnetic methods and sonar scanning technology, exploring its application in the salt cavern cavity creation process. During well cavity creation, the cavity creation process monitoring technology based on wide-area electromagnetic methods, employing a "well-to-ground transmission-to-reception" approach, can monitor the electromagnetic response caused by electrical changes after the cavity-creating fluid enters the ground, acquire electromagnetic time difference anomalies, reflect the swept range of the cavity-creating fluid, track and characterize the dominant dissolution channels, and monitor the leading edge position of the formed cavity in real time. The wide-area electromagnetic method is not used for preliminary scanning, but rather to supplement the blind spots of sonar measurements by real-time monitoring of the salt cavern expansion state and evaluating cavity connectivity.

[0101] In some embodiments, this application categorizes the technical means into four aspects: vertical monitoring range, lateral expansion assessment, anomaly warning, and connectivity judgment, thereby evaluating the advantages and disadvantages of sonar technology and wide-area electromagnetic method. First, regarding the vertical monitoring range, sonar technology can only measure the brine-filled cavity portion, while wide-area electromagnetic method can detect the dissolution front of unfilled salt rock. Second, regarding lateral expansion assessment, sonar technology is limited by well location, resulting in a short lateral detection distance, while wide-area electromagnetic method can monitor the dissolution halo range within a 200m radius. Third, regarding anomaly warning, sonar technology has difficulty identifying interlayers or impurity zones in the salt layer, while wide-area electromagnetic method can provide warnings through resistivity abrupt changes (>50Ω·m). Fourth, regarding connectivity judgment, sonar technology requires cross-measurement from multiple wells and necessitates multi-well data support, while wide-area electromagnetic method can assess the hydraulic connectivity of adjacent cavities using only a single well.

[0102] The salt cavern cavity monitoring method provided in this application can be executed by a salt cavern cavity monitoring device 200. This application uses the salt cavern cavity monitoring device 200 executing the salt cavern cavity monitoring method as an example to illustrate the salt cavern cavity monitoring device 200 provided in this application.

[0103] Please see Figure 7 This is a structural schematic diagram of a salt cavern monitoring device 200 provided in an embodiment of this application. Figure 7 As shown, the salt cavern cavity monitoring device 200 includes: The first data acquisition module 201 is used to perform sonar scanning measurements on the formed salt cavern cavity based on the sonar baseline, and acquire sonar reflection intensity data and cavity morphology data; wherein, the sonar baseline is pre-calibrated before water injection to create a cavity in the target rock salt layer section; The second data acquisition module 202 is used to acquire real-time electromagnetic data of the target rock salt layer based on the wide-area electromagnetic method. The first determining module 203 is used to determine the dissolution front and dissolution state of the salt cavern cavity based on real-time electromagnetic data and original formation resistivity background field data; wherein, the original formation resistivity background field data is obtained in advance based on the wide-area electromagnetic method before water injection to create a cavity in the target rock salt layer. The second determining module 204 is used to determine the stable state of the cavity morphology of the salt cavern based on sonar reflection intensity data, original formation resistivity background field data and real-time electromagnetic data.

[0104] In some implementations, the raw formation resistivity background field data includes the background electric field and the initial resistivity, and the real-time electromagnetic data includes the real-time electric field and the real-time resistivity. The first determining module 203 can be used for: The location of the dissolution front of the salt cavern cavity was determined based on the background electric field and the real-time electric field. Based on the real-time resistivity, the rate of resistivity decrease is calculated, and based on the rate of resistivity decrease, the dissolution state within the salt cavern cavity is determined. The boundary of refractory erosion during the dissolution process is determined based on the real-time resistivity.

[0105] In some implementations, the first determining module 203 may be used to: If the rate of decrease in resistivity is less than the first rate value, it is determined that the dissolution state within the salt cavern is normal. If the rate of decrease in resistivity is greater than the second rate value, it is determined that the dissolution state within the salt cavern is abnormal, triggering a danger warning; wherein, the second rate value is greater than the first rate value.

[0106] In some implementations, the first determining module 203 may be used to: When the real-time resistivity is greater than or equal to the first resistivity, the insoluble corrosion boundary encountered during the dissolution process is determined. When the real-time resistivity is less than the first resistivity, it is determined that no insoluble corrosion boundary was encountered during the dissolution process.

[0107] In some implementations, the first determining module 203 may be used to: Trigger encrypted sonar scanning measurements at the location corresponding to the real-time resistivity, and update the sonar reflection intensity data and cavity morphology data.

[0108] In some implementations, the second determining module 204 may be used to: Based on a pre-acquired comprehensive dissolution rate model, the dissolution rate value is obtained according to sonar reflection intensity data, initial resistivity, and real-time resistivity; wherein, the comprehensive dissolution rate model is established based on resistivity and sonar reflection intensity; If the degree of solubility exceeds the first threshold, the stability of the cavity morphology of the salt cavern is determined to be abnormal, triggering a hazard warning.

[0109] In some implementations, the comprehensive solubility model is constrained by the following expression: ; Where L is the degree of solubility, ρ0 is the initial resistivity, and ρ t For real-time resistivity, α is the resistivity weighting coefficient, and A t β is the current sonar reflection amplitude, A0 is the initial sonar reflection amplitude, and β is the sonar weighting coefficient.

[0110] Since the salt cavern cavity monitoring device 200 adopts all the technical solutions of the salt cavern cavity monitoring method of the above embodiments, it has at least all the beneficial effects brought about by the technical solutions of the above embodiments, and will not be described again here.

[0111] Figure 8 This is a schematic diagram of the hardware structure of the electronic device provided in the embodiments of this application.

[0112] This electronic device may include a processor 301 and a memory 302 storing computer program instructions.

[0113] Specifically, the processor 301 may include a central processing unit (CPU), an application-specific integrated circuit (ASIC), or one or more integrated circuits that can be configured to implement the embodiments of this application.

[0114] Memory 302 may include mass storage for data or instructions. For example, and not limitingly, memory 302 may include a hard disk drive (HDD), floppy disk drive, flash memory, optical disk, magneto-optical disk, magnetic tape, or Universal Serial Bus (USB) drive, or a combination of two or more of these. Where appropriate, memory 302 may include removable or non-removable (or fixed) media. Where appropriate, memory 302 may be internal or external to the integrated gateway disaster recovery device. In a particular embodiment, memory 302 is non-volatile solid-state memory.

[0115] In some embodiments, memory 302 may include read-only memory (ROM), random access memory (RAM), disk storage media device, optical storage media device, flash memory device, electrical, optical, or other physical / tangible memory storage device. Thus, generally, memory includes one or more tangible (non-transitory) computer-readable storage media (e.g., memory devices) encoded with software including computer-executable instructions, and when the software is executed (e.g., by one or more processors), it is operable to perform the operations described with reference to the method according to one aspect of this disclosure.

[0116] The processor 301 reads and executes computer program instructions stored in the memory 302 to implement any of the salt cavern monitoring methods in the above embodiments.

[0117] In one example, the electronic device may also include a communication interface 303 and a bus 310. For example, Figure 8 As shown, the processor 301, memory 302, and communication interface 303 are connected through bus 310 and complete communication with each other.

[0118] The communication interface 303 is mainly used to realize communication between various modules, devices, units and / or equipment in the embodiments of this application.

[0119] Bus 310 includes hardware, software, or both, that couples components of an online data traffic metering device together. For example, and not limitingly, the bus may include an Accelerated Graphics Port (AGP) or other graphics bus, an Enhanced Industry Standard Architecture (EISA) bus, a Front Side Bus (FSB), HyperTransport (HT) interconnect, an Industry Standard Architecture (ISA) bus, an Infinite Bandwidth Interconnect, a Low Pin Count (LPC) bus, a memory bus, a Microchannel Architecture (MCA) bus, a Peripheral Component Interconnect (PCI) bus, a PCI-Express (PCI-X) bus, a Serial Advanced Technology Attachment (SATA) bus, a Video Electronics Standards Association Local (VLB) bus, or other suitable buses, or combinations of two or more of these. Where appropriate, bus 310 may include one or more buses. Although specific buses are described and illustrated in embodiments of this application, any suitable bus or interconnect is contemplated herein.

[0120] This electronic device can perform the salt cavern monitoring method in the embodiments of this application, thereby achieving the combination of Figure 1 and Figure 7 The method and apparatus for monitoring salt cavern formation are described.

[0121] Furthermore, in conjunction with the salt cavern cavity monitoring method in the above embodiments, this application embodiment can provide a computer storage medium for implementation. The computer storage medium stores computer program instructions; when these computer program instructions are executed by a processor, they implement any of the salt cavern cavity monitoring methods in the above embodiments.

[0122] It should be clarified that this application is not limited to the specific configurations and processes described above and shown in the figures. For the sake of brevity, detailed descriptions of known methods are omitted here. In the above embodiments, several specific steps are described and shown as examples. However, the method process of this application is not limited to the specific steps described and shown. Those skilled in the art can make various changes, modifications, and additions, or change the order of steps, after understanding the spirit of this application.

[0123] The functional blocks shown in the above-described structural diagram can be implemented as hardware, software, firmware, or a combination thereof. When implemented in hardware, they can be, for example, electronic circuits, application-specific integrated circuits (ASICs), appropriate firmware, plug-ins, function cards, etc. When implemented in software, the elements of this application are programs or code segments used to perform the required tasks. Programs or code segments can be stored on a machine-readable medium or transmitted over a transmission medium or communication link via data signals carried on a carrier wave. "Machine-readable medium" can include any medium capable of storing or transmitting information. Examples of machine-readable media include electronic circuits, semiconductor memory devices, ROM, flash memory, erasable ROM (EROM), floppy disks, CD-ROMs, optical disks, hard disks, fiber optic media, radio frequency (RF) links, etc. Code segments can be downloaded via computer networks such as the Internet, intranets, etc.

[0124] It should also be noted that the exemplary embodiments mentioned in this application describe methods or systems based on a series of steps or apparatus. However, this application is not limited to the order of the above steps; that is, the steps can be performed in the order mentioned in the embodiments, or in a different order, or several steps can be performed simultaneously.

[0125] The aspects of this disclosure have been described above with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of this disclosure. It should be understood that each block in the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, or other programmable data processing apparatus to produce a machine such that these instructions, executable via the processor of the computer or other programmable data processing apparatus, enable the implementation of the functions / actions specified in one or more blocks of the flowchart illustrations and / or block diagrams. Such a processor can be, but is not limited to, a general-purpose processor, a special-purpose processor, a special application processor, or a field-programmable logic circuit. It is also understood that each block in the block diagrams and / or flowcharts, and combinations of blocks in the block diagrams and / or flowcharts, can also be implemented by special-purpose hardware performing the specified functions or actions, or can be implemented by a combination of special-purpose hardware and computer instructions.

[0126] The above description is merely a specific implementation of this application. Those skilled in the art will clearly understand that, for the sake of convenience and brevity, the specific working processes of the systems, modules, and units described above can be referred to the corresponding processes in the foregoing method embodiments, and will not be repeated here. It should be understood that the protection scope of this application is not limited thereto. Any person skilled in the art can easily conceive of various equivalent modifications or substitutions within the technical scope disclosed in this application, and these modifications or substitutions should all be covered within the protection scope of this application.

Claims

1. A method for monitoring salt cavern formation, characterized in that, include: Based on the sonar baseline, the formed salt cavern cavity is scanned and measured with sonar to obtain sonar reflection intensity data and cavity morphology data; wherein, the sonar baseline is pre-calibrated before water injection to create a cavity in the target rock salt layer; Real-time electromagnetic data of the target rock salt layer is obtained based on the wide-area electromagnetic method. Based on the real-time electromagnetic data and the original formation resistivity background field data, the dissolution front and dissolution state of the salt cavern are determined; wherein, the original formation resistivity background field data is obtained in advance based on the wide-area electromagnetic method before water injection to create a cavity in the target rock salt layer; Based on the sonar reflection intensity data, the original formation resistivity background field data, and the real-time electromagnetic data, the stable state of the cavity morphology of the salt cavern is determined.

2. The method for monitoring salt cavern formation according to claim 1, characterized in that, The original formation resistivity background field data includes background electric field and initial resistivity, and the real-time electromagnetic data includes real-time electric field and real-time resistivity; The step of determining the dissolution front and dissolution state of the salt cavern based on the real-time electromagnetic data and the original formation resistivity background field data includes: The position of the dissolution front of the salt cavern is determined based on the background electric field and the real-time electric field. Based on the real-time resistivity, the rate of resistivity decrease is calculated, and based on the rate of resistivity decrease, the dissolution state within the salt cavern cavity is determined. Based on the real-time resistivity, the refractory erosion boundary during the dissolution process is determined.

3. The method for monitoring salt cavern formation according to claim 2, characterized in that, The step of calculating the resistivity decrease rate based on the real-time resistivity and determining the dissolution state within the salt cavern cavity based on the resistivity decrease rate includes: If the rate of decrease in resistivity is less than the first rate value, it is determined that the dissolution state within the salt cavern is normal. If the rate of decrease in resistivity is greater than the second rate value, it is determined that the dissolution state within the salt cavern is abnormal, triggering a danger warning; wherein the second rate value is greater than the first rate value.

4. The method for monitoring salt cavern formation according to claim 2, characterized in that, The step of determining the insoluble erosion boundary during the dissolution process based on the real-time resistivity includes: When the real-time resistivity is greater than or equal to the first resistivity, it is determined that the insoluble erosion boundary is encountered during the dissolution process; If the real-time resistivity is less than the first resistivity, it is determined that the refractory erosion boundary was not encountered during the dissolution process.

5. The method for monitoring salt cavern formation according to claim 4, characterized in that, After determining that the sparingly soluble dissolution boundary is encountered during the dissolution process, the salt cavern monitoring method further includes: Trigger encrypted sonar scanning measurements at the location corresponding to the real-time resistivity, and update the sonar reflection intensity data and the cavity morphology data.

6. The method for monitoring salt cavern creation according to claim 2 or 5, characterized in that, The step of determining the stable state of the cavity morphology of the salt cavern based on the sonar reflection intensity data, the original formation resistivity background field data, and the real-time electromagnetic data includes: Based on a pre-acquired comprehensive dissolution rate model, the dissolution rate value is obtained according to the sonar reflection intensity data, the initial resistivity, and the real-time resistivity; wherein, the comprehensive dissolution rate model is established based on resistivity and sonar reflection intensity; If the degree of dissolution is greater than a first threshold, the stability of the cavity morphology of the salt cavern is determined to be abnormal, triggering a hazard warning.

7. The method for monitoring salt cavern formation according to claim 6, characterized in that, The comprehensive solubility model is constrained by the following expression: ； Where L is the degree of solubility, ρ0 is the initial resistivity, and ρ t Let A be the real-time resistivity, α be the resistivity weighting coefficient, and A be the real-time resistivity. t β is the current sonar reflection amplitude, A0 is the initial sonar reflection amplitude, and β is the sonar weighting coefficient.

8. A salt cavern cavity monitoring device, characterized in that, include: The first data acquisition module is used to perform sonar scanning measurements on the formed salt cavern cavity based on the sonar baseline, and acquire sonar reflection intensity data and cavity morphology data; wherein, the sonar baseline is pre-calibrated before water injection to create a cavity in the target rock salt layer section; The second data acquisition module is used to acquire real-time electromagnetic data of the target rock salt layer based on the wide-area electromagnetic method. The first determining module is used to determine the dissolution front and dissolution state of the salt cavern cavity based on the real-time electromagnetic data and the original formation resistivity background field data; wherein, the original formation resistivity background field data is obtained in advance based on the wide-area electromagnetic method before water injection to create a cavity in the target rock salt layer; The second determining module is used to determine the stable state of the cavity morphology of the salt cavern based on the sonar reflection intensity data, the original formation resistivity background field data, and the real-time electromagnetic data.

9. An electronic device, characterized in that, It includes a processor and a memory, the memory storing a program or instructions that can run on the processor, the program or instructions being executed by the processor to implement the steps of the salt cavern monitoring method as described in any one of claims 1 to 7.

10. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores computer-executable instructions for causing a computer to perform the salt cavern monitoring method as described in any one of claims 1 to 7.

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