Method for monitoring and early warning of gas storage well operation risk and related device

Abstract

The application discloses a kind of gas storage well operation risk monitoring and early warning method and related device.The method comprises: obtaining the real-time monitoring data of wellbore;According to the annular pressure value in the real-time monitoring data of wellbore, it is predicted whether wellbore has safety risk, and in the case where it is predicted that the wellbore has safety risk, corresponding early warning is carried out.It can realize real-time monitoring to gas storage well operation and carry out evaluation and early warning, to effectively prevent the safety problem caused by leakage problem of gas storage well.

Description

Technical Field

[0001] This invention relates to the field of underground gas storage production and operation, and in particular to a method and device for monitoring and early warning of operational risks of gas storage wells. Background Technology

[0002] Currently, my country's gas storage facilities are entering a development stage that emphasizes both large-scale construction and efficient operation. The underground systems of these facilities experience alternating loads, presenting numerous and widespread risks. Furthermore, some facilities have been in operation for over thirty years, resulting in widespread annular pressurization and highlighting well integrity issues. Leaks could render these facilities unusable and seriously threaten public safety. Existing technologies generally employ decentralized and singular monitoring methods for gas storage well operation.

[0003] There are issues with insufficient coverage of gas storage well operation monitoring types and a lack of real-time monitoring and data acquisition methods. Furthermore, existing methods that rely on post-event assessments through gas storage well data analysis are too slow for large-scale gas storage well operational risk assessments, failing to provide real-time monitoring and early warning, resulting in poor real-time warning capabilities. Additionally, current technologies use wellbore data from the time of manufacture for risk assessment, leading to low accuracy in risk assessment results. Therefore, there is an urgent need for a method to monitor gas storage well operation in real-time and provide accurate assessment and early warning to prevent safety issues caused by gas storage well leaks. Summary of the Invention

[0004] In the existing technology, the coverage of the types of monitoring for the operation of gas storage wells is insufficient, and there is a lack of real-time monitoring and data acquisition methods; moreover, the risk assessment of the operation of gas storage wells over a large area is too lagging, and there is a lack of a real-time early warning integrated system for large-scale gas storage wells. In view of the above problems, the embodiments of the present invention provide a method and related device for monitoring and early warning of the operation risk of gas storage wells.

[0005] In a first aspect, embodiments of the present invention provide a risk monitoring and early warning method for the operation of gas storage wells, comprising:

[0006] Obtain real-time monitoring data of the wellbore;

[0007] Based on the annular pressure value in the real-time monitoring data of the wellbore, it is predicted whether the wellbore has a safety risk, and if the wellbore is predicted to have a safety risk, a corresponding early warning is issued.

[0008] In one embodiment, the step of predicting whether the wellbore has a safety risk based on the annular pressure value in the real-time monitoring data of the wellbore, and issuing a corresponding early warning if the wellbore is predicted to have a safety risk, includes:

[0009] If the annular pressure value obtained several times in a row continues to rise, and the annular pressure value exceeds the thermally induced pressure threshold, then the wellbore is determined to be at risk of abnormal annular pressure; the thermally induced pressure threshold is determined based on the gas pressure generated by the expansion of liquid and compression of gas in the annulus;

[0010] Correspondingly, abnormal annular pressure is assessed and an early warning is issued for the wellbore.

[0011] In one embodiment, the thermally induced pressure threshold is determined in the following manner:

[0012] The thermally induced pressure threshold is calculated using the following formula:

[0013]

[0014] In the above formula, P t The thermally induced annular pressure threshold is given by: T0 being the initial average annular temperature, P0 being the pressure, and T1 being the average thermodynamic temperature of the gas in the current production annular space. h is the value of the pressure threshold. a h1 is the height of the gas in the annulus, h1 is the height of the liquid in the annulus, α is the coefficient of liquid expansion, and ΔT is the average temperature change.

[0015] In one embodiment, it also includes:

[0016] Obtain static engineering construction data and periodic inspection data of the wellbore;

[0017] Based on the wellbore material data in the static engineering construction data and the periodic inspection data of the wellbore, the remaining strength of the tubing string, the remaining strength of the casing string, and the remaining strength of the wellhead equipment are determined respectively.

[0018] The pressure-bearing range of the wellbore is determined based on the remaining strength of the tubing string, the remaining strength of the casing string, and the remaining strength of the wellhead equipment. The pressure-bearing range characterizes the minimum value of the maximum permissible annular pressure of the wellbore.

[0019] Based on the range corresponding to the annular pressure value within the pressure bearing range, the risk level corresponding to the annular pressure value is determined;

[0020] Based on the risk level corresponding to the annular pressure value, the wellbore is subjected to annular pressure classification early warning, and the annular pressure classification early warning of the wellbore corresponds to the risk level corresponding to the annular pressure value.

[0021] In one embodiment, the periodic inspection data of the wellbore includes changes in casing string damage and changes in tubing string damage.

[0022] Based on the wellbore material data in the static engineering construction data and the periodic inspection data of the wellbore, the remaining strength of the tubing string and the remaining strength of the casing string are determined, respectively, and the following is also included:

[0023] Based on the wellbore material data and the casing string damage change value, the remaining strength of the casing string is calculated, and the remaining strength of the casing string is the strength of the casing string under the current state.

[0024] Based on the wellbore material data and the change value of the tubing string damage, the remaining strength of the tubing string is calculated, which is the strength of the tubing string under the current condition.

[0025] In one embodiment, the periodic inspection data of the wellbore also includes wellhead device leakage detection values, wellbore wall thickness, wellbore leakage detection values, ultrasonic testing results, and gamma spectral logging results;

[0026] After obtaining the static engineering construction data and periodic inspection data of the wellbore, the following is also included:

[0027] Based on the change value of the casing damage, the remaining life of the casing is determined. If the remaining life of the casing is greater than the preset remaining life threshold of the casing and the remaining strength of the casing is greater than the preset remaining strength threshold of the casing, then the casing is judged to be in a safe state.

[0028] Based on the change value of the tubing string damage, the remaining life of the tubing string is determined. If the remaining life of the tubing string is greater than the preset remaining life threshold of the tubing string, and the remaining strength of the tubing string is greater than the preset remaining strength threshold of the tubing string, then the tubing string is judged to be in a safe state.

[0029] Based on the wellbore material data, a first wall thickness threshold is determined for the wellbore, which is the theoretical minimum wall thickness required for the internal pressure of the wellbore. Based on the first wall thickness threshold and the preset wellbore corrosion allowance value, a second wall thickness threshold is obtained for the wellbore. If the wall thickness of the wellbore is greater than the second wall thickness threshold, it is determined that the remaining wall thickness of the wellhead device has reached the preset standard.

[0030] Based on the ultrasonic testing results, the level of burial defects in the wellbore is determined;

[0031] If the remaining wall thickness of the wellhead device reaches the preset standard and the level of the buried defect is less than the preset threshold for the level of the buried defect, then the wellhead device is determined to be in a safe state.

[0032] If the detected wellbore leakage value is less than the preset wellbore leakage threshold, it is determined that the tubing string and casing string are in a sealed state.

[0033] If the leakage detection value of the wellhead device is less than the preset wellhead device leakage threshold, the wellhead device is determined to be in a sealed state.

[0034] If the gamma spectral logging results do not show a continuous accumulation of flowable gas, then the cement sheath in the wellbore is considered to be in a sealed state.

[0035] In one embodiment, the method further includes:

[0036] If the wellhead gas leakage value in the real-time monitoring data exceeds the preset wellhead leakage threshold, it is determined that the wellbore has a wellhead leakage risk; correspondingly, a wellhead leakage warning is issued for the wellbore.

[0037] If the wellhead rise value in the real-time monitoring data exceeds the preset wellhead rise threshold, it is determined that the wellbore has a wellhead rise risk; correspondingly, a wellhead rise warning is issued for the wellbore.

[0038] If the annular fluid level value in the real-time monitoring data is lower than the preset annular fluid level threshold, or if the annular fluid level value in the real-time monitoring data continues to decrease for several consecutive times, then it is determined that the wellbore has an annular fluid level risk, and correspondingly, an annular fluid level warning is issued for the wellbore.

[0039] Secondly, embodiments of the present invention provide a risk monitoring and early warning device for the operation of gas storage wells, comprising:

[0040] The acquisition module is used to acquire real-time monitoring data of the wellbore;

[0041] The risk monitoring and early warning module is used to predict whether the wellbore has a safety risk based on the annulus pressure value in the real-time monitoring data of the wellbore, and to issue a corresponding early warning if the wellbore is predicted to have a safety risk.

[0042] Thirdly, embodiments of the present invention provide a computer storage medium storing computer-executable instructions, which, when executed by a processor, implement the aforementioned risk monitoring and early warning method for the operation of a gas storage well.

[0043] Fourthly, embodiments of the present invention provide a terminal device, including: a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the program to implement the above-described risk monitoring and early warning method for the operation of a gas storage well.

[0044] Fifthly, embodiments of the present invention provide a computer program product, the computer program product including a computer program, which, when executed by a processor, implements the above-described risk monitoring and early warning method for the operation of a gas storage well.

[0045] The beneficial effects of the above-described technical solutions provided in the embodiments of the present invention include at least the following:

[0046] The risk monitoring and early warning method for gas storage well operation provided in this invention enables real-time safety risk monitoring of the gas storage well based on real-time monitoring data of the wellbore. When a safety risk exists in the gas storage well, an early warning corresponding to the predicted safety risk is issued. By using real-time monitoring data, the risks existing in the wellbore can be predicted in a timely manner, solving the problem of poor real-time prediction of gas storage safety risks in the prior art. Furthermore, it ensures the safe operation of the gas storage and improves the daily risk management capability.

[0047] Furthermore, the risk monitoring and early warning method for gas storage well operation provided in this embodiment of the invention determines the remaining strength and remaining life of the casing string by acquiring the casing string damage change value in the periodic inspection data of the wellbore, and thus determines whether the casing string is in a safe state. It also acquires the tubing string damage change value to determine the remaining strength and remaining life of the tubing string, and thus determines whether the tubing string is in a safe state. Based on the wellbore material data in the static engineering construction data of the wellbore, a second wall thickness threshold is determined. If the remaining wall thickness of the wellhead device is greater than the second wall thickness threshold, it is determined that the remaining wall thickness of the wellhead device has reached a preset standard. Based on the periodic inspection data of the wellbore, the sealing performance of the tubing string, casing string, wellhead device, and cement sheath is determined. By using the data of the wellbore in the current state, compared with the initial data of the wellbore used in the prior art, it is possible to more accurately assess whether the tubing string, casing string, and wellhead device of the wellbore are in a safe state, and more accurately assess whether the tubing string, casing string, wellhead device, and cement sheath are in a sealed state.

[0048] Other features and advantages of the invention will be set forth in the description which follows, and will be apparent in part from the description, or may be learned by practicing the invention. The objects and other advantages of the invention may be realized and obtained by means of the structures particularly pointed out in the written description, claims, and drawings.

[0049] The technical solution of the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. Attached Figure Description

[0050] The accompanying drawings are provided to further illustrate the invention and form part of the specification. They are used in conjunction with embodiments of the invention to explain the invention and do not constitute a limitation thereof. In the drawings:

[0051] Figure 1 This is a flowchart of a risk monitoring and early warning method for gas storage well operation in an embodiment of the present invention;

[0052] Figure 2 This is a flowchart of the method for classifying and warning of annular pressure in a wellbore according to an embodiment of the present invention;

[0053] Figure 3 This is a schematic diagram illustrating the cloud map effect of the well barrier safety factor in an embodiment of the present invention;

[0054] Figure 4 This is a schematic diagram of the annular pressure classification of a well in an embodiment of the present invention.

[0055] Figure 5 This is one of the structural schematic diagrams of a risk monitoring and early warning device for determining the operation of a gas storage well in an embodiment of the present invention;

[0056] Figure 6 This is the second schematic diagram of the risk monitoring and early warning device for determining the operation of gas storage wells in this embodiment of the invention. Detailed Implementation

[0057] Exemplary embodiments of the present disclosure will now be described in more detail with reference to the accompanying drawings. While exemplary embodiments of the present disclosure are shown in the drawings, it should be understood that the present disclosure may be implemented in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the disclosure to those skilled in the art.

[0058] The inventors discovered in their work that in the existing technology, the assessment of operational risks of large-scale gas storage wells is relatively lagging, and it is impossible to achieve real-time monitoring and early warning of gas storage wells, resulting in poor real-time early warning. After further research and development, the inventors made this invention. The embodiments of this invention provide a method and related device for monitoring and early warning of operational risks of gas storage wells.

[0059] Example

[0060] The risk monitoring and early warning method for gas storage well operation will be described in detail below with reference to specific examples.

[0061] This invention provides a risk monitoring and early warning method for the operation of gas storage wells, the process of which is as follows: Figure 1 As shown, it includes the following steps:

[0062] Step S1: Obtain real-time monitoring data of the wellbore;

[0063] Step S2: Based on the annulus pressure value in the real-time monitoring data of the real-time monitoring data well, predict whether the real-time monitoring data well has a safety risk, and issue a corresponding early warning if the real-time monitoring data well is predicted to have a safety risk.

[0064] In some optional embodiments, in step S1 above, the real-time monitoring data of the wellbore is obtained through monitoring hardware deployed at each wellhead and well site. The monitoring hardware is equipment for real-time monitoring of the operation of the gas storage well. For example, wellhead oil pressure detection equipment can monitor the wellhead oil pressure value in real time; annular pressure monitoring equipment at various levels can monitor the annular pressure at various levels in real time; wellhead gas leakage monitoring equipment can monitor the wellhead gas leakage value in real time; wellhead lift monitoring equipment can monitor the wellhead lift value in real time; and annular fluid level monitoring equipment can monitor the annular fluid level value in real time. Specifically, for example, monitoring hardware as shown in Table 1 is deployed at each wellhead and well site, and data acquisition software is deployed at the site. The data acquisition software can collect the data detected in real time by the monitoring hardware.

[0065] Table 1:

[0066]

[0067]

[0068] In some optional embodiments, step S2 above, which predicts whether the wellbore has a safety risk based on the annulus pressure value in the real-time monitoring data of the wellbore, and issues a corresponding early warning if a safety risk is predicted, can be achieved in the following way:

[0069] If the annular pressure values ​​obtained consecutively increase for several consecutive times, and the annular pressure values ​​exceed the thermally induced pressure threshold, then the wellbore is determined to have an abnormal annular pressure risk. The thermally induced pressure threshold is determined based on the gas pressure generated by the expansion of liquid and the compression of gas in the annulus. Accordingly, an abnormal annular pressure assessment and early warning are conducted on the wellbore.

[0070] The remote pressure transmitter enables real-time monitoring of annular pressure at various levels at the wellhead. By continuously monitoring the annular pressure values ​​of the wellbore several times, the dynamic changes in annular pressure can be obtained. At the same time, considering the influence of thermally induced annular pressure, abnormal annular pressure can be indicated. If the annular pressure values ​​measured several times continuously rise and exceed the thermally induced pressure threshold, it can be determined that there is abnormal annular pressure.

[0071] The thermally induced pressure threshold is the maximum gas pressure generated by the expansion of liquid and compression of gas within a closed annulus due to temperature rise. The thermally induced pressure threshold can be calculated using the following formula:

[0072]

[0073] In the above formula, P t1. Thermally induced annular pressure threshold, in MPa; 2. Initial annular average temperature, taken as the average thermodynamic temperature of the formation at the depth from the wellhead to the annular fluid surface, in K; 3. Pressure, in MPa; 4. T1, the average thermodynamic temperature of the gas currently being produced in the annulus, in K; 5. h a h1 is the height of the gas in the annulus; h1 is the height of the liquid in the annulus; α is the coefficient of liquid expansion; ΔT is the average temperature change, which can be obtained by equaling T1-T0.

[0074] Gas storage wells have multiple annulus levels. The annulus pressure values ​​of each level are monitored in real time via remote pressure transmitters. If the annulus pressure value continues to rise and exceeds the thermally induced pressure threshold, it is determined that the wellbore has an abnormal annulus pressure risk. In other words, by monitoring the annulus pressure value in real time, it is possible to determine whether the wellbore has an abnormal annulus pressure risk. Furthermore, if an abnormal annulus pressure risk is predicted, an abnormal annulus pressure assessment and early warning corresponding to the abnormal annulus pressure risk can be performed in real time. This achieves real-time monitoring and early warning for gas storage wells, solving the problems of excessively delayed operational risk assessment and poor real-time early warning for gas storage wells.

[0075] In some optional embodiments, the risk monitoring and early warning method for gas storage well operation provided by this invention can also perform graded early warning of annular pressure in the wellbore. Specifically, for example... Figure 2 As shown, this can be achieved in the following way;

[0076] Step S21: Obtain static engineering construction data and periodic inspection data of the wellbore;

[0077] Step S22: Based on the wellbore material data and periodic inspection data in the static engineering construction data of the wellbore, determine the remaining strength of the tubing string, the remaining strength of the casing string, and the remaining strength of the wellhead equipment, respectively.

[0078] Step S23: Determine the pressure-bearing range of the wellbore based on the remaining strength of the tubing string, the remaining strength of the casing string, and the remaining strength of the wellhead equipment. The pressure-bearing range characterizes the minimum value of the maximum allowable annular pressure of the wellbore.

[0079] Step S24: Determine the risk level corresponding to the annular pressure value based on the interval corresponding to the annular pressure value within the pressure bearing range;

[0080] Step S25: Based on the risk level corresponding to the annular pressure value, perform annular pressure classification and early warning for the wellbore. The annular pressure classification and early warning for the wellbore corresponds to the risk level corresponding to the annular pressure value.

[0081] In some optional embodiments, in step S21 above, the periodic inspection data of the wellbore is the data obtained by periodically inspecting the wellbore during the operation of the gas storage well. For example, in accordance with relevant standards, the wellbore's string damage data (casing string damage data and tubing string damage data), cementing quality data, wellhead equipment strength and wellhead equipment sealing data can be tested periodically to obtain the change in string damage, wellhead equipment leakage detection value, cylinder wall thickness, wellbore leakage detection value, ultrasonic test results and gamma spectral logging results.

[0082] In contrast to the periodic inspection data of the wellbore, there is the static engineering construction data of the wellbore. The static engineering construction data of the wellbore is obtained from data such as the well history and geological summary of each drilled and completed well. Therefore, the static engineering construction data of the wellbore does not change over time.

[0083] In some optional embodiments, step S22 above, which determines the remaining strength of the tubing string and the remaining strength of the casing string based on the wellbore material data and the periodic inspection data of the wellbore in the static engineering construction data, can be achieved in the following way:

[0084] Based on the wellbore material data and casing string damage change values, the remaining strength of the casing string is calculated. The remaining strength of the casing string is the strength of the casing string under the current condition.

[0085] Based on the wellbore material data and the change in tubing string damage, the remaining strength of the tubing string is calculated. The remaining strength of the tubing string is the strength of the tubing string under the current condition.

[0086] In some optional embodiments, in step 23 above, due to the corrosion effect, the strength of the tubing string and casing string in the wellbore will gradually decrease over time. Therefore, the remaining strength of the tubing string is the strength of the tubing string in the current state obtained through tubing string damage detection, and the remaining strength of the casing string is the strength of the casing string in the current state obtained through tubing string damage detection. The remaining strength of the tubing string and casing string is lower than the initial strength at the factory, which can reflect the current pressure bearing capacity of the tubing string and casing string. Based on the verification of the remaining strength of the tubing string, casing string and wellhead equipment in the wellbore, and considering the influence of the external extrusion force of the annular fluid surface in the wellbore inner tubing string and the internal pressure force of the outer tubing string, the pressure bearing range of the wellbore can be obtained within the preset safety margin. The pressure bearing range can characterize the maximum allowable value of the annular pressure at each level of the wellhead.

[0087] The pressure-bearing range is divided into intervals, and the risk level of annular pressure is determined based on the intervals corresponding to the annular pressure values ​​in the real-time monitoring data within the pressure-bearing range; accordingly, annular pressure classification and early warning are carried out for the wellbore.

[0088] In some optional embodiments, the pressure range is divided into intervals. For example, the range less than 60% of the pressure range can be divided into one interval, which indicates that the annulus in the wellbore is in a normal pressurized range during production and can be used for normal production. The range between 60% and 70% of the pressure range can be divided into another interval, which indicates that the annulus pressure value needs to be monitored more intensively. The range between 70% and 80% of the pressure range can be divided into another interval, which indicates that the annulus pressure is in a high-risk state and the annulus pressure type needs to be diagnosed, and the leakage point and leakage flow need to be analyzed. The range between 80% and the pressure range can be divided into another interval, which indicates that the annulus pressure is in a dangerous state and certain control measures need to be taken, such as well shut-in or well workover.

[0089] In addition, each of the divided intervals can be represented by a different color, such as Figure 3 As shown in Table 3, an annular pressure classification chart for the well is generated. Based on the interval corresponding to the annular pressure value and the oil pressure value, the risk level of the annular pressure is determined, and the risk of the well is indicated by the color of the interval corresponding to the annular pressure value.

[0090] Table 3:

[0091] Pressure threshold range color 80% * Maximum allowable pressure < Annular pressure ≤ Maximum allowable pressure red 70% * maximum permissible pressure < annular pressure ≤ 80% * maximum permissible pressure orange color 60% * maximum permissible pressure < annular pressure ≤ 70 * maximum permissible pressure yellow When the annular pressure is ≤60% of the maximum allowable pressure green

[0092] The table above categorizes annular pressure using color coding. The green area represents the recommended pressurized range. Entering the yellow area requires close monitoring of the annular pressure. Entering the orange area necessitates pressure relief and diagnosis of the cause of the annular pressure issue. Entering the red area poses a significant risk to wellbore integrity, requiring well workover measures. During production operations, the annular pressure at the injection / production wellhead should be kept within the green area shown in the diagram. When the annular pressure enters the orange area, diagnostic testing is required to analyze the source, leakage flow rate, and location of the annular pressure. When the actual annular pressure is in the red area, control measures should be implemented, and well workover should be carried out promptly.

[0093] It should be noted that the remaining strength of the wellhead equipment, casing string, and tubing string obtained from the periodic inspection data of the wellbore can also serve as the basis for predicting and warning of risks.

[0094] In some optional embodiments, based on real-time monitoring data of the wellbore, it is predicted whether the wellbore poses a safety risk, and if a safety risk is predicted, a corresponding early warning is issued, including:

[0095] If the gas leakage value at the wellhead exceeds the preset wellhead leakage threshold, the well is determined to have a wellhead leakage risk; correspondingly, a wellhead leakage warning is issued for the well.

[0096] If the wellhead rise exceeds the preset wellhead rise threshold, the well is determined to have a wellhead rise risk; correspondingly, a wellhead rise warning is issued for the well.

[0097] If the annular fluid level is lower than the preset annular fluid level threshold, or if the annular fluid level value of several real-time monitoring data continues to decrease, it is determined that the wellbore has an annular fluid level risk, and correspondingly, an annular fluid level warning is issued for the wellbore.

[0098] The annular liquid level threshold can be calculated by multiplying the packer depth by the annular filling coefficient. For example, the filling coefficient can be taken as 0.9 to 0.96.

[0099] Among them, the continuous decrease in the annular liquid level value in several real-time monitoring data can refer to a difference of more than 100m between two measurements of the annular liquid level within one year.

[0100] In some optional embodiments, after obtaining the static engineering construction data and periodic inspection data of the wellbore, the safety and sealing status of the wellbore can be assessed by the following methods:

[0101] (1) Determine the remaining life of the casing string based on the change value of the casing string damage. If the remaining life of the casing string is greater than the preset remaining life threshold of the casing string and the remaining strength of the casing string is greater than the preset remaining strength threshold of the casing string, then the casing string is judged to be in a safe state.

[0102] (2) Determine the remaining life of the tubing string based on the change value of the tubing string damage. If the remaining life of the tubing string is greater than the preset remaining life threshold of the tubing string and the remaining strength of the tubing string is greater than the preset remaining strength threshold of the tubing string, then the tubing string is judged to be in a safe state.

[0103] (3) Based on the well material data, determine the first wall thickness threshold of the well. The first wall thickness threshold is the theoretical minimum wall thickness required for the internal pressure of the well. Based on the first wall thickness threshold and the preset well corrosion allowance value, obtain the second wall thickness threshold of the well. If the wall thickness of the well is greater than the second wall thickness threshold, then determine that the remaining wall thickness of the wellhead device meets the preset standard.

[0104] The corrosion allowance S can be taken as an empirical value, for example, S = 4.5 mm.

[0105] (4) Determine the level of buried defects in the wellbore based on the ultrasonic test results;

[0106] If the remaining wall thickness of the wellhead device reaches the preset standard and the level of buried defects is less than the preset threshold for buried defects, then the wellhead device is judged to be in a safe state.

[0107] (5) If the wellbore leakage detection value is less than the preset wellbore leakage threshold, it is determined that the tubing string and casing string are in a sealed state.

[0108] (6) If the wellhead device leakage detection value is less than the preset wellhead device leakage threshold, the wellhead device is judged to be in a sealed state.

[0109] (7) If the gamma spectral logging results do not show a continuous accumulation of flowable gas, then the cement sheath in the wellbore is considered to be in a sealed state.

[0110] In the process of calculating the remaining strength of the casing string and the tubing string, the remaining internal pressure resistance, external extrusion resistance, and tensile strength of the production casing string or tubing string throughout the well section are checked using the principles of materials mechanics and tubing mechanics. In other words, the safety factor = actual maximum load / remaining strength, and the indicators are: remaining internal pressure resistance safety factor ≥ 1.1, remaining external extrusion resistance safety factor ≥ 1.0, and remaining internal pressure resistance safety factor ≥ 1.3.

[0111] The remaining life calculation is mainly based on the principles of materials mechanics to calculate the minimum wall thickness required for the tubing to work safely under a certain internal pressure condition. This wall thickness is supplemented with a certain safety margin (an empirical value of 1.5 mm) as the critical wall thickness. Then the remaining life is the time required for the tubing to corrode from the current wall thickness to the critical wall thickness under uniform corrosion conditions (i.e., T = (current wall thickness - critical wall thickness) / corrosion rate). Based on experience, the remaining life is generally required to be ≥10 years. If it is less than 10 years, more frequent inspections or a reduction in internal pressure are required.

[0112] Existing methods for obtaining remaining strength, such as selecting the minimum wall thickness data for two-dimensional verification, are contrasted by the present invention, which comprehensively utilizes theories of materials mechanics and tubing mechanics, along with finite element analysis, to perform calculations and establish a three-dimensional model of the field detection data. This enables visualized three-dimensional evaluation. For example, by employing logging methods such as "multi-arm caliper + electromagnetic flaw detection," and analyzing information such as orientation, caliper diameter, and wall thickness reflected in dozens of "multi-arm caliper + electromagnetic flaw detection" curves, a three-dimensional model of tubing inner diameter damage is established, which can more accurately reflect the actual tubing damage situation. Based on this, calculations for remaining strength and remaining life of the tubing are performed, enabling more accurate prediction of whether there are safety risks in the wellbore and providing risk warnings.

[0113] The above-mentioned determination of whether the casing string and tubing string are in a sealed state can be made by using downhole leakage detection instruments (noise, ultrasonic, etc.); it can also be qualitatively determined by the annular fluid level and annular pressure conditions. The specific method is as follows: if the annular fluid level drops by more than 50m in two consecutive tests, it is determined that the tubing string-packer in annulus A is leaking; in the annular pressure relief and recovery test, annulus A remains sealed and pressurized, and annulus B is vented and then closed. If the pressure in annulus B rises slowly and the pressure in annulus A drops, and they change synchronously, and finally the pressures in annulus A and B tend to be the same; if annulus A is vented, and the pressure in annulus B drops during the release of annulus A, but the rate of drop is lower than that in annulus A, it can be determined that the production casing is not sealed.

[0114] In determining whether the cement sheath in the wellbore is in a sealed state, commonly used cementing quality testing methods such as acoustic amplitude / variable density and ultrasonic logging can be employed. These methods detect whether the cement sheath and casing, and the cement sheath and formation, are tightly bonded. If the cementing quality of the caprock section is consistently excellent within a preset threshold in the logging results, the cement sheath is considered to be well-sealed, for example, with a preset threshold of 25m. In addition, radioactive logging methods such as gamma spectroscopy can be used. This logging method can detect inside the tubing to determine whether there is gas accumulation outside the casing. In this embodiment of the invention, the specific method of radioactive logging methods such as gamma spectroscopy is as follows: detection is performed under both pressurized and vented conditions in the B annulus to compare whether there is flowable gas accumulation outside the casing. If no continuous flowable gas accumulation is detected in the gas storage caprock section, the cement sheath is considered to be well-sealed.

[0115] In addition, a three-dimensional model can be built using the inspection data of the casing string, tubing string, and cement sheath of the wellbore. A cloud map can then be used to display the well barrier safety factor of the wellbore on the established three-dimensional model, with the display effect as follows: Figure 3 As shown.

[0116] Based on the periodic inspection data of the wellbore, the safety and sealing status of the gas storage well are assessed. The assessment objects, inspection data sources and algorithms are shown in Table 2.

[0117] Table 2 Evaluation Objects, Data Sources, and Algorithms

[0118]

[0119] Based on the same inventive concept, embodiments of the present invention also provide a risk monitoring and early warning device for the operation of gas storage wells, the structure of which is as follows: Figure 4 As shown, it includes:

[0120] The acquisition module 31 is used to acquire real-time monitoring data of the wellbore;

[0121] The risk warning module 32 is used to predict whether the wellbore has a safety risk based on the annulus pressure value in the real-time monitoring data of the wellbore, and to issue a corresponding warning if the wellbore is predicted to have a safety risk.

[0122] In some optional embodiments, the acquisition module includes a monitoring hardware module, a data acquisition module, and a database module. The monitoring hardware module is equipped with equipment for real-time monitoring of the operation of the gas storage well, which can realize the functions of real-time measurement data and remote communication transmission. The equipment for real-time monitoring includes wellhead oil pressure monitors and annular pressure monitors at various levels, wellhead gas leakage monitors, wellhead lift monitors, annular fluid level monitors, etc.

[0123] The data acquisition module can collect real-time monitoring data from the monitoring hardware module and transmit the real-time monitoring data to the database module.

[0124] The database module is used to access static engineering construction data and real-time monitoring and dynamic engineering construction data for each wellbore. The database module can be a tree-structured hierarchy, with levels including: gas storage type, gas storage group, gas storage unit, and single well.

[0125] The evaluation module and risk warning module can interact and communicate with the database module to provide early warnings and perform well integrity evaluations based on the real-time monitoring data stored in the database module.

[0126] In some alternative embodiments, such as Figure 5 As shown, the risk monitoring and early warning device for gas storage well operation can also include a decision support module. The decision support module can form an intelligent diagnostic workflow through big data analysis, machine learning and other algorithms, diagnose and analyze the causes of risks, quantify and evaluate the degree of risk, predict potential risk factors, and provide suggestions for control measures for high-risk wells.

[0127] Among them, the data that provides machine learning for the decision support module is the data from previous wellbore inspections, and the integrity evaluation is the data from previous integrity evaluations. Specifically, the gas storage wellbore needs to undergo integrity inspection and evaluation every 3-5 years. If it has been carried out 4 times in 20 years, then these 4 times are the results of previous inspections.

[0128] Regarding the risk monitoring and early warning device for the operation of gas storage wells in the above embodiments, the specific methods of each module's operation have been described in detail in the embodiments related to the method, and will not be elaborated here.

[0129] Based on the same inventive concept, embodiments of the present invention also provide a computer storage medium storing computer-executable instructions, which, when executed by a processor, implement the above-described method for evaluating the effectiveness of cathodic protection of pipelines in the blind zone of crossing sections or the above-described method for constructing a polarization potential threshold table for pipelines in the blind zone of crossing sections.

[0130] Based on the same inventive concept, embodiments of the present invention also provide a terminal device, including: a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the program, it implements the above-described method for evaluating the effectiveness of cathodic protection of pipelines in the blind zone of the crossing section or the above-described method for constructing a polarization potential threshold table for pipelines in the blind zone of the crossing section.

[0131] Based on the same inventive concept, this embodiment of the invention also provides a computer program product, characterized in that the computer program product includes a computer program, which, when executed by a processor, implements the above-described method for evaluating the effectiveness of cathodic protection of pipelines in the blind zone of crossing sections or the above-described method for constructing a polarization potential threshold table for pipelines in the blind zone of crossing sections.

[0132] Unless otherwise specifically stated, terms such as processing, calculation, operation, determination, display, etc., may refer to the actions and / or processes of one or more processing or computing systems or similar devices that represent the manipulation and conversion of data representing physical (e.g., electronic) quantities within the registers or memory of the processing system into other data similarly representing physical quantities within the memory, registers, or other such information storage, transmission, or display devices of the processing system. Information and signals can be represented using any of a variety of different techniques and methods. For example, data, instructions, commands, information, signals, bits, symbols, and chips mentioned throughout the above description can be represented by voltage, current, electromagnetic waves, magnetic fields or particles, light fields or particles, or any combination thereof.

[0133] It should be understood that the specific order or hierarchy of steps in the disclosed process is an example of an exemplary method. Based on design preferences, it should be understood that the specific order or hierarchy of steps in the process may be rearranged without departing from the scope of this disclosure. The appended method claims provide elements of various steps in an exemplary order and are not intended to limit the scope to the specific order or hierarchy described.

[0134] In the detailed description above, various features are combined together in a single embodiment to simplify this disclosure. This approach to disclosure should not be construed as reflecting an intention that embodiments of the claimed subject matter require more features than are explicitly stated in each claim. Rather, as reflected in the appended claims, the invention is presented with fewer features than all of the features in a single disclosed embodiment. Therefore, the appended claims are hereby explicitly incorporated into the detailed description, with each claim representing a separate preferred embodiment of the invention.

[0135] Those skilled in the art will also understand that the various illustrative logic blocks, modules, circuits, and algorithm steps described in conjunction with the embodiments herein can be implemented as electronic hardware, computer software, or a combination thereof. To clearly illustrate the interchangeability between hardware and software, the various illustrative components, blocks, modules, circuits, and steps described above are generally described in terms of their functionality. Whether such functionality is implemented as hardware or software depends on the specific application and the design constraints imposed on the overall system. Those skilled in the art can implement the described functionality in alternative ways for each specific application; however, such implementation decisions should not be construed as departing from the scope of this disclosure.

[0136] The steps of the methods or algorithms described in conjunction with the embodiments herein can be directly embodied in hardware, software modules executed by a processor, or a combination thereof. The software modules can reside in RAM memory, flash memory, ROM memory, EPROM memory, EEPROM memory, registers, hard disks, removable disks, CD-ROMs, or any other form of storage medium well known in the art. An exemplary storage medium is connected to the processor, enabling the processor to read information from and write information to the storage medium. Of course, the storage medium can also be a component of the processor. The processor and storage medium can reside in an ASIC. The ASIC can reside in a user terminal. Alternatively, the processor and storage medium can exist as discrete components in the user terminal.

[0137] For software implementation, the techniques described in this application can be implemented using modules (e.g., procedures, functions, etc.) that perform the functions described in this application. This software code can be stored in memory units and executed by a processor. The memory units can be implemented within the processor or outside the processor; in the latter case, they are communicatively coupled to the processor via various means, as is well known in the art.

[0138] The foregoing description includes examples of one or more embodiments. It is certainly impossible to describe all possible combinations of components or methods in order to describe the above embodiments, but those skilled in the art will recognize that further combinations and arrangements of the various embodiments are possible. Therefore, the embodiments described herein are intended to cover all such changes, modifications, and variations that fall within the scope of the appended claims. Furthermore, the term "comprising" as used in the specification or claims is interpreted in a manner similar to the term "including," as interpreted when used as a conjunction in the claims. Additionally, the use of any term "or" in the specification of the claims is intended to mean "non-exclusive or."

Claims

1. A risk monitoring and early warning method for the operation of gas storage wells, characterized in that, include: Obtain real-time monitoring data of the wellbore; Based on the annular pressure value in the real-time monitoring data of the wellbore, predict whether the wellbore has a safety risk, and if the wellbore is predicted to have a safety risk, issue a corresponding early warning. The method of predicting whether the wellbore has a safety risk based on the annular pressure value in the real-time monitoring data of the wellbore, and issuing a corresponding early warning if the wellbore is predicted to have a safety risk, includes: If the annular pressure value obtained several times in a row continues to rise, and the annular pressure value exceeds the thermally induced pressure threshold, then it is determined that the wellbore has an abnormal annular pressure risk; the thermally induced pressure threshold is determined based on the gas pressure generated by the expansion of liquid and compression of gas in the annulus; Correspondingly, abnormal annular pressure is assessed and an early warning is issued for the wellbore.

2. The method as described in claim 1, characterized in that, The thermally induced pressure threshold is determined in the following manner: The thermally induced pressure threshold is calculated using the following formula: In the above formula, P t The thermally induced annular pressure threshold is given by: T0 being the initial average annular temperature, P0 being the pressure, and T1 being the average thermodynamic temperature of the gas in the current production annular space. h is the value of the pressure threshold. a h is the height of the gas in the annulus. l Let α be the height of the liquid in the annulus, α be the coefficient of liquid expansion, and ΔT be the average temperature change.

3. The method as described in claim 1, characterized in that, Also includes: Obtain static engineering construction data and periodic inspection data of the wellbore; Based on the wellbore material data in the static engineering construction data and the periodic inspection data of the wellbore, the remaining strength of the tubing string, the remaining strength of the casing string, and the remaining strength of the wellhead equipment are determined respectively. The pressure-bearing range of the wellbore is determined based on the remaining strength of the tubing string, the remaining strength of the casing string, and the remaining strength of the wellhead equipment. The pressure-bearing range characterizes the minimum value of the maximum permissible annular pressure of the wellbore. Based on the range corresponding to the annular pressure value within the pressure bearing range, the risk level corresponding to the annular pressure value is determined; Based on the risk level corresponding to the annular pressure value, the wellbore is subjected to annular pressure classification early warning, and the annular pressure classification early warning of the wellbore corresponds to the risk level corresponding to the annular pressure value.

4. The method as described in claim 3, characterized in that, The periodic inspection data of the wellbore includes the change value of casing string damage and the change value of tubing string damage; Based on the wellbore material data in the static engineering construction data and the periodic inspection data of the wellbore, the remaining strength of the tubing string and the remaining strength of the casing string are determined, respectively, and the following is also included: Based on the wellbore material data and the casing string damage change value, the remaining strength of the casing string is calculated, and the remaining strength of the casing string is the strength of the casing string under the current state. Based on the wellbore material data and the change value of the tubing string damage, the remaining strength of the tubing string is calculated, which is the strength of the tubing string under the current condition.

5. The method as described in claim 4, characterized in that, The periodic inspection data of the wellbore also includes wellhead equipment leakage detection values, wellbore wall thickness, wellbore leakage detection values, ultrasonic test results, and gamma spectral logging results; After obtaining the static engineering construction data and periodic inspection data of the wellbore, the following is also included: Based on the change value of the casing damage, the remaining life of the casing is determined. If the remaining life of the casing is greater than the preset remaining life threshold of the casing and the remaining strength of the casing is greater than the preset remaining strength threshold of the casing, then the casing is judged to be in a safe state. Based on the change value of the tubing string damage, the remaining life of the tubing string is determined. If the remaining life of the tubing string is greater than the preset remaining life threshold of the tubing string, and the remaining strength of the tubing string is greater than the preset remaining strength threshold of the tubing string, then the tubing string is judged to be in a safe state. Based on the wellbore material data, a first wall thickness threshold is determined for the wellbore, which is the theoretical minimum wall thickness required for the internal pressure of the wellbore. Based on the first wall thickness threshold and the preset wellbore corrosion allowance value, a second wall thickness threshold is obtained for the wellbore. If the wall thickness of the wellbore is greater than the second wall thickness threshold, it is determined that the remaining wall thickness of the wellhead device has reached the preset standard. Based on the ultrasonic testing results, the level of burial defects in the wellbore is determined; If the remaining wall thickness of the wellhead device reaches the preset standard and the level of the buried defect is less than the preset threshold for the level of the buried defect, then the wellhead device is determined to be in a safe state. If the detected wellbore leakage value is less than the preset wellbore leakage threshold, it is determined that the tubing string and casing string are in a sealed state. If the leakage detection value of the wellhead device is less than the preset wellhead device leakage threshold, the wellhead device is determined to be in a sealed state. If the gamma spectral logging results do not show a continuous accumulation of flowable gas, then the cement sheath in the wellbore is considered to be in a sealed state.

6. The method as described in claim 1, characterized in that, The method further includes: If the wellhead gas leakage value in the real-time monitoring data exceeds the preset wellhead leakage threshold, it is determined that the wellbore has a wellhead leakage risk; correspondingly, a wellhead leakage warning is issued for the wellbore. If the wellhead rise value in the real-time monitoring data exceeds the preset wellhead rise threshold, it is determined that the wellbore has a wellhead rise risk; correspondingly, a wellhead rise warning is issued for the wellbore. If the annular fluid level value in the real-time monitoring data is lower than the preset annular fluid level threshold, or if the annular fluid level value in the real-time monitoring data continues to decrease for several consecutive times, then it is determined that the wellbore has an annular fluid level risk, and correspondingly, an annular fluid level warning is issued for the wellbore.

7. A risk monitoring and early warning device for the operation of a gas storage well, comprising: The acquisition module is used to acquire real-time monitoring data of the wellbore; The risk monitoring and early warning module is used to predict whether the wellbore has a safety risk based on the annular pressure value in the real-time monitoring data of the wellbore, and to issue a corresponding early warning if the wellbore is predicted to have a safety risk; the step of predicting whether the wellbore has a safety risk based on the annular pressure value in the real-time monitoring data of the wellbore, and issuing a corresponding early warning if the wellbore is predicted to have a safety risk, includes: If the annular pressure value obtained several times in a row continues to rise, and the annular pressure value exceeds the thermally induced pressure threshold, then the wellbore is determined to have an abnormal annular pressure risk; the thermally induced pressure threshold is determined based on the gas pressure generated by the expansion of liquid and the compression of gas in the annulus; accordingly, an abnormal annular pressure assessment and early warning is performed on the wellbore.

8. A computer storage medium, characterized in that, The computer storage medium stores computer-executable instructions, which, when executed by a processor, implement a risk monitoring and early warning method for the operation of a gas storage well as described in any one of claims 1-6.

9. A terminal device, characterized in that, include: A memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor, when executing the program, implements a risk monitoring and early warning method for the operation of a gas storage well as described in any one of claims 1-6.

10. A computer program product, characterized in that, The computer program product includes a computer program that, when executed by a processor, implements a risk monitoring and early warning method for the operation of a gas storage well as described in any one of claims 1-6.

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