Gas well oil pipe erosion safety evaluation method and related device

Abstract

The invention discloses a gas well oil pipe erosion safety evaluation method and a related device. The method comprises the following steps: acquiring key parameters of a target well; according to the obtained key parameters of the target well, an erosion test is conducted, and a test result is obtained; constructing a gas well oil pipe erosion mathematical model according to the test result; the erosion mathematical model is used for conducting erosion prediction on a target well pipe column; and judging the erosion safety of the oil pipe under the current gas production amount according to the erosion prediction. By obtaining the key parameters of the target well, the test result closer to the actual condition can be obtained, the erosion condition of the oil pipe can be reflected more accurately, the mathematical model constructed based on the erosion test result can simulate and predict the erosion condition of the oil pipe under different gas production rates, the erosion mechanism can be understood, and the method is suitable for popularization and application. According to the method, firstly, a theoretical basis is provided for subsequent optimization design and safety management, secondly, erosion prediction can be conducted on the tubular column of the target well by means of the established erosion mathematical model, and therefore safety accidents caused by erosion are avoided.

Description

Technical Field

[0001] This invention belongs to the field of gas well tubing erosion safety technology, specifically relating to a gas well tubing erosion safety assessment method and related apparatus. Background Technology

[0002] With the continuous optimization of my country's energy structure and the development of the petroleum industry, the demand for natural gas is increasing year by year. During gas well production, the gas inside the pipes often carries formation gravel, which can cause erosion damage to the pipe walls. Furthermore, compared to straight pipe sections, for pipes that have buckled, the erosive medium inside the pipe is more likely to cause more severe erosion damage at specific angles to the locally bent sections. Because the pipes serve downhole for a long time, as erosion damage intensifies, the wall thickness decreases, reducing the pipe's resistance to internal pressure, external extrusion, and tensile strength, thus reducing its remaining life and even leading to pipe leaks or ruptures. Therefore, in the process of gas well integrity management, the assessment of pipe erosion safety is extremely important. For the analysis of pipe erosion, some researchers have established erosion calculation models, such as the particle erosion theory models E / CRC, OKa, DNV, and Salama, but these models are difficult to directly evaluate the erosion safety of gas well pipes.

[0003] Currently, both domestically and internationally, the assessment of tubing erosion safety primarily relies on evaluating the critical erosion flow rate of the fluid inside the tubing. This calculation method is based on the formula proposed in the American Petroleum Institute (API) RP 14 standard. In the formula, V e Critical erosion velocity, ft / s; ρ m The density of fluid mixture within the tubing, lb / ft 3 C represents the critical erosion coefficient, which is dimensionless. The value of the critical erosion coefficient C is closely related to the actual erosion and wear resistance of the tubing. Since tubing erosion and wear are affected by various factors (flow velocity, temperature, sand content, corrosive media, tubing geometry, etc.), the value of the critical erosion coefficient C varies under different operating conditions and tubing specifications. For these reasons, on-site process designers and operators can only determine the value based on experience. For high-temperature, high-pressure, high-yield gas wells, C is taken as 80-120; for gas storage injection-production wells, C is taken as 100-150; and for ordinary gas wells, C can be greater than 200. It can be seen that the current on-site determination of the critical erosion flow rate mainly relies on production experience, making it impossible to formulate a reasonable and scientific critical erosion flow rate based on different well conditions. Therefore, it is impossible to accurately evaluate the impact of the current gas production rate on tubing erosion safety.

[0004] Besides the API RP 14 standard, for the safety assessment of gas well tubing erosion, patent CN 111222281 A proposes a method for determining the erosion failure risk of injection-production tubing in gas reservoirs. This method calculates the probability of erosion failure of the injection-production tubing based on parameters such as temperature and pressure. Its limitation is that it only applies the erosion risk equation obtained under a specific operating condition, making it applicable only to injection-production tubing in sandy gas reservoirs under specific conditions. It cannot be applied to the evaluation of erosion safety in all gas well tubing, and field personnel find it difficult to use this method for analysis. Patent CN 109344534 B proposes a method and device for determining the critical erosion velocity of injection-production tubing. This method utilizes a neural network algorithm to train a large number of gas reservoir injection-production tubing erosion test results, thereby enabling the output of the injection-production tubing erosion rate under a specific operating condition. This method primarily targets injection and production tubing in gas storage facilities and cannot be extended to all gas well tubing. Furthermore, the calculation process in this area is a "black box" algorithm, with its accuracy heavily reliant on the quantity and reliability of the input data. Due to numerous influencing factors, the erosion rate variations among different target well tubing can differ significantly depending on operating conditions. Therefore, it is difficult to predict the erosion rate of well B tubing by training the erosion rate of well A tubing. In addition, this method only provides a calculation method for the critical erosion rate, with a standard erosion rate of 0.076 mm / a. When the predicted tubing erosion rate exceeds 0.076 mm / a, erosion is considered to have occurred. Using this value as a safe threshold for tubing erosion rate is overly conservative. In practice, a certain degree of erosion should be allowed, as long as the erosion rate is controlled within the tubing's maximum permissible erosion rate. In summary, existing gas well tubing erosion safety assessment methods lack rationality and practicality, making it difficult to meet the current needs of increasing production in natural gas wells and improving storage capacity in gas storage injection and production wells. There is an urgent need to propose a scientific and reasonable gas well tubing erosion safety assessment method to provide on-site personnel with a method for calculating critical erosion flow rates for production gas wells under different operating conditions, so as to evaluate tubing erosion safety. Summary of the Invention

[0005] The purpose of this invention is to solve the problems in the prior art and to provide a method and related apparatus for safety evaluation of gas well tubing erosion.

[0006] To achieve the above objectives, the present invention employs the following technical solution:

[0007] Firstly, a method for safety assessment of gas well tubing erosion is provided, including:

[0008] Obtain key parameters of the target well;

[0009] Erosion tests were conducted based on the obtained key parameters of the target well, and the test results were obtained.

[0010] A mathematical model of gas well tubing erosion was constructed based on the experimental results.

[0011] The erosion mathematical model is used to predict the erosion of the target well string;

[0012] Based on the erosion prediction, it is determined that the tubing is safe under the current gas production rate.

[0013] Furthermore, the acquisition of key parameters of the target well specifically includes:

[0014] The well depth, operating parameters, tubing parameters, and sand production analysis of the target well are obtained. The operating parameters include wellhead temperature, wellhead pressure, geothermal gradient, and gas production rate during the operating phase.

[0015] The tubing string parameters include tubing outer diameter, tubing wall thickness, casing outer diameter, and casing wall thickness;

[0016] The sand output analysis includes the sand mass concentration and sand particle size.

[0017] Furthermore, erosion tests are conducted based on the obtained key parameters of the target well, and the test results are obtained, including:

[0018] Determine the parameters for the erosion test;

[0019] The sample pretreatment is performed according to the determined test parameters;

[0020] The pretreated sample was subjected to an erosion test, and the test results were obtained. The test results are based on a dimensionless erosion rate calculation formula, which is as follows:

[0021] Furthermore, based on the experimental results, a mathematical model for gas well tubing erosion is constructed, specifically including:

[0022] Based on the erosion test results of gas well tubing materials under multi-factor conditions, an erosion mathematical model applicable to gas well tubing materials was established. This erosion mathematical model can be expressed as:

[0023] Furthermore, the erosion prediction of the target well string is performed using the aforementioned erosion mathematical model, including:

[0024] The ultimate permissible erosion rate of the target well tubing, the critical erosion velocity of the downhole gas, and the critical erosion flow rate of the target well are calculated.

[0025] Furthermore, based on the erosion prediction, the safety of the oil pipe erosion under the current gas production rate is determined as follows:

[0026] The calculated critical erosion flow rate is compared with the actual gas production rate. If the actual gas production rate is less than the critical erosion flow rate, the current tubing erosion is judged to be in a safe state.

[0027] If the actual gas extraction rate is greater than or equal to the critical erosion flow rate, the current gas extraction rate is judged to be too high, which is an unsafe state.

[0028] Furthermore, the formula for calculating the critical erosion flow rate is as follows:

[0029] Secondly, a gas well tubing erosion safety assessment system is provided, including:

[0030] The data acquisition module is used to acquire key parameters of the target well;

[0031] The model building module is used to build mathematical models of gas well tubing erosion.

[0032] The erosion prediction module is used to predict the erosion of the target well string.

[0033] The judgment module is used to determine the safety of tubing erosion under the current gas production rate.

[0034] Thirdly, an electronic device is provided, including a memory, a processor, and a computer program stored in the memory and executable in the processor, wherein the processor executes the computer program to implement the steps of the gas well tubing erosion safety assessment method as described above.

[0035] Fourthly, a computer-readable storage medium is provided, the computer-readable storage medium storing a computer program, which, when executed by a processor, implements the gas well tubing erosion safety assessment method as described above.

[0036] Compared with the prior art, the present invention has the following beneficial effects:

[0037] 1. By obtaining key parameters of the target well, experimental results closer to actual conditions can be obtained, more accurately reflecting the erosion situation of the tubing. The mathematical model constructed based on the erosion test results can simulate and predict tubing erosion under different gas production rates, helping to understand the erosion mechanism and providing a theoretical basis for subsequent optimization design and safety management. Secondly, using the established erosion mathematical model, erosion prediction of the tubing string in the target well can be performed. The prediction results can identify potential erosion risks in advance, allowing for corresponding prevention and repair measures to avoid safety accidents caused by erosion. Finally, based on the erosion prediction results, the tubing erosion safety under the current gas production rate can be assessed. This not only helps operators understand the current safety situation but also provides a scientific basis for formulating reasonable gas production plans.

[0038] 2. By obtaining detailed well depth data, we can more accurately understand the underground environment of the gas well. Obtaining operating parameters can provide a comprehensive understanding of the working status of the gas well at different operating stages. Obtaining tubing string parameters such as tubing outer diameter, tubing wall thickness, casing outer diameter, and casing wall thickness is crucial for assessing the strength and durability of the tubing.

[0039] 3. The determination of test parameters makes the results of erosion tests closer to the actual situation. Sample pretreatment can eliminate the influence of differences in the sample itself on the test results. The pretreated sample can better simulate the working state of the actual oil pipe in the gas well, improve the accuracy and reliability of the test results, and conduct erosion tests on the pretreated sample to obtain erosion test results, providing key data for subsequent erosion prediction and safety evaluation. Attached Figure Description

[0040] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of the present invention and should not be regarded as a limitation on the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0041] Figure 1 The flowchart of the gas well tubing erosion safety assessment method provided by the present invention;

[0042] Figure 2 A schematic diagram of the test apparatus in the gas well tubing erosion safety evaluation method provided by the present invention;

[0043] Figure 3 The dimensionless erosion rate variation curves under different gas flow velocities in the gas well tubing erosion safety evaluation method provided by the present invention;

[0044] Figure 4 The dimensionless erosion rate variation curves under different impact angles in the gas well tubing erosion safety evaluation method provided by the present invention.

[0045] Figure 5 This is a schematic diagram of the simulation prediction results of the tubing erosion rate under normal conditions in the gas well tubing erosion safety evaluation method provided by the present invention.

[0046] Figure 6 This is a schematic diagram of the simulation prediction results of the tubing erosion rate under sinusoidal buckling state in the gas well tubing erosion safety evaluation method provided by the present invention.

[0047] Figure 7 This is a schematic diagram of the simulation prediction results of the tubing erosion rate under helical buckling state in the gas well tubing erosion safety evaluation method provided by the present invention.

[0048] Figure 8 This is a schematic diagram of the gas well tubing erosion safety assessment system provided by the present invention;

[0049] The components include: 1. Air compressor; 2. Throttling valve; 3. Circulation pipeline; 4. Heating belt; 5. Flow meter; 6. Thermometer; 7. Erosion chamber; 8. Sand storage tank. Detailed Implementation

[0050] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. The components of the embodiments of the present invention described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0051] Therefore, the following detailed description of the embodiments of the invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the invention without inventive effort are within the scope of protection of the invention.

[0052] It should be noted that similar labels and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.

[0053] In the description of the embodiments of the present invention, it should be noted that if terms such as "upper," "lower," "horizontal," or "inner" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship commonly used when the product of the invention is in use, they are only for the convenience of describing the present invention 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 the present invention. Furthermore, terms such as "first" and "second" are only used to distinguish descriptions and should not be construed as indicating or implying relative importance.

[0054] Furthermore, the use of the term "horizontal" does not imply that the component must be absolutely horizontal, but rather that it can be slightly tilted. For example, "horizontal" simply means that its direction is more horizontal than "vertical," and does not mean that the structure must be completely horizontal, but can be slightly tilted.

[0055] In the description of the embodiments of the present invention, it should also be noted that, unless otherwise explicitly specified and limited, the terms "set," "install," "connect," and "link" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in the present invention according to the specific circumstances.

[0056] The present invention will now be described in further detail with reference to the accompanying drawings:

[0057] This invention provides a method and related apparatus for safety assessment of gas well tubing erosion.

[0058] like Figure 1 As shown, in a first aspect, embodiments of the present invention provide a method for safety assessment of gas well tubing erosion, comprising:

[0059] S101. Obtain key parameters of the target well; for example, the key parameters of the target well specifically include well depth, operating parameters, tubing string parameters, and sand production analysis. Among them, operating parameters include wellhead temperature, wellhead pressure, geothermal gradient, and gas production during the operating stage; tubing string parameters include tubing outer diameter, tubing wall thickness, casing outer diameter, and casing wall thickness; sand production analysis includes sand mass concentration and sand particle size. Using these parameters to conduct erosion tests can yield test results that are closer to actual conditions and can more accurately reflect the erosion of the tubing.

[0060] S102. Conduct erosion tests based on the obtained key parameters of the target well and obtain the test results; for example, conduct erosion tests on gas well tubing materials under multi-factor conditions. During the test, the main factors considered include gas flow rate, impact angle, temperature, gravel particle size, and gravel concentration. The erosion rate is expressed using the weight loss method. The test apparatus used during the test includes... Figure 2 As shown, the device is a gas-solid two-phase flow erosion test device, which mainly includes an air compressor 1, a throttle valve 2, a circulation pipeline 3, a heating belt 4, a flow meter 5, a thermometer 6, an erosion chamber 7, and a sand storage tank 8.

[0061] Specifically, the steps for conducting erosion tests on gas well tubing materials under multiple factors are as follows:

[0062] 1) Determine the parameters for the erosion test;

[0063] (a) The formula for calculating gas flow velocity is as follows:

[0064]

[0065] In the formula, v is the gas velocity, m / s; Q is the gas extraction rate, m³ / s.3 / s; A is the cross-sectional area inside the oil pipe, m 2 ;P sc Pressure under standard conditions, MPa; Z is the downhole gas compressibility factor; T is the downhole gas temperature; P is the downhole pressure; Z sc T is the gas compressibility factor under standard conditions. sc The gas temperature is given under standard conditions.

[0066] Consider at least 5 different flow velocities. For example, if the calculated result of v is 150 m / s, then the 5 different flow velocities are set to 30 m / s, 60 m / s, 90 m / s, 120 m / s and 150 m / s respectively.

[0067] (b) The impact angle is considered to vary between 0 and 90°, and can be set to 0°, 15°, 30°, 45°, 60°, 75° and 90°;

[0068] (c) The maximum temperature during the test is considered to be the bottom-hole temperature of the target well; its calculation formula is as follows:

[0069] T b =T h +kh (3-2)

[0070] In the formula, T b T represents the bottom hole temperature, in °C. h T represents the wellhead temperature (°C); k represents the geothermal gradient (°C / m); and h represents the well depth. Considering at least five different temperatures, if T... b The calculation result is 100℃, and can be set to 20℃, 40℃, 60℃, 80℃ and 100℃;

[0071] (d) Quartz sand particles were selected. The particle size and particle mass concentration were determined based on the sand output analysis results, with the average particle size d0 being the most significant. p The particle size can be set to: 200μm, 400μm, 600μm, 800μm, and 1000μm; particle mass concentration φ p It can be set to 0.25%, 0.5%, 0.75%, 1%, 1.25%, and 1.5%.

[0072] 2) Perform sample pretreatment according to the determined test parameters; for example, the test sample is ultrasonically cleaned for ten minutes and then dried. The dried sample is weighed and recorded on a high-precision digital electronic scale to obtain the mass of the sample before erosion. The sample is installed after sample pretreatment.

[0073] 3) Conduct an erosion test on the pretreated sample and obtain the test results; for example, turn on the air compressor 1, adjust the pressure regulating valve to control the gas flow rate in the pipe to meet the test parameter requirements, turn on the heating belt 4 installed on the circulation pipeline 3 to heat the gas to the specified temperature, adjust the valve below the sand storage tank 8 to control the falling speed of the sand and gravel to adjust the particle mass concentration; after the equipment is debugged, start timing. When the test set time is reached, turn off the air compressor 1 and the valve below the sand storage tank 8, remove the sample, wash the sand and gravel adhering to the sample surface with clean water, clean the test sample with ultrasonic cleaning for ten minutes, and then dry it. Place the dried sample on a high-precision digital electronic scale to weigh and record the mass of the sample after erosion; finally, record the operating conditions of this test and the mass loss me of the sample before and after erosion, and the test ends; the test result is the dimensionless erosion rate calculation formula of the erosion test, combined with Figure 3 and Figure 4 The dimensionless erosion rate ER1 of this erosion test is calculated as follows:

[0074]

[0075] In the formula, ER1 is the dimensionless erosion rate, mg / mg; m e m represents the mass loss of the sample before and after erosion. p The mass of particles consumed in the erosion test.

[0076] S103. Construct a mathematical model for gas well tubing erosion based on the test results; for example, based on the test results of gas well tubing material erosion under multi-factor conditions, an erosion mathematical model applicable to gas well tubing materials is established, which can be expressed as:

[0077]

[0078] In the formula, ER1 is the dimensionless erosion rate, mg / mg; f(α) is the erosion coefficient equation under the influence of impact angle; v is the gas velocity, m / s; n is the impact velocity exponent; f(t) is the erosion coefficient equation under the influence of temperature; f(d) is the gas velocity coefficient equation under the influence of temperature. p The equation for the erosion coefficient under the influence of particle size is as follows: This is the erosion coefficient equation under the influence of particle concentration, where C is an empirical constant.

[0079] The erosion coefficient equations under different factors in Equation (3-4) can all be obtained by erosion tests of small samples of gas well tubing materials under multi-factor conditions. A control group is set up in the test, and the erosion coefficient equation value under the influence of each parameter in the equation obtained by the test group is set to 1. By obtaining the influence law of parameter variables on the erosion coefficient, the erosion coefficient equations under different factors are formed.

[0080] S104. Predict erosion of the target well string using the aforementioned erosion mathematical model; for example, such as... Figure 5 , Figure 6 and Figure 7 As shown, based on the geometric models of the target well tubing structure under both normal and buckling conditions, with the buckling condition considering both sinusoidal and helical buckling modes, computational fluid dynamics analysis was performed using ANSYS.FLUENT software to simulate and predict tubing erosion. When selecting the erosion mathematical model, the erosion mathematical model formed in step S103 was imported into ANSYS.FLUENT. Based on the actual working conditions of the target well, the maximum erosion rate of the tubing was calculated under different gas velocities, temperatures, particle sizes, particle concentrations, and tubing geometric structures. Using mathematical fitting methods, a fitting formula was formed between the maximum erosion rate of the tubing and the above-mentioned different factors, which can be expressed as:

[0081]

[0082] In the formula, ER2 is the maximum erosion rate of the tubing, mm / a; v is the flow velocity in the tubing, m / s; n' is the flow velocity exponent; g(t) is the erosion coefficient equation under the influence of temperature; g(d) is the flow velocity coefficient under the influence of temperature. p The equation for the erosion coefficient under the influence of particle size is as follows: is the erosion coefficient equation under the influence of particle concentration; g(S) is the erosion coefficient equation under the influence of the tubing structure, which is affected by the tubing size and buckling state, and M is an empirical constant.

[0083] Calculation of the ultimate permissible erosion rate for the target well string;

[0084] The formula for calculating the critical wall thickness of an oil pipe is:

[0085]

[0086] In the formula, S i The rated internal pressure resistance safety factor is taken as 1.1; K o p is the overpressure coefficient during pressure testing, taken as 1.1; ie The effective internal pressure is MPa; D is the nominal outer diameter of the oil pipe, mm. k t f is the wall thickness deviation coefficient, taken as 0.875; ymn β is the minimum yield strength of the pipe material, in MPa; β is the attenuation correction value at the pipe thread, taken as 1.5.

[0087] Then, the ultimate permissible erosion rate of the tubing can be calculated based on the critical wall thickness:

[0088]

[0089] In the formula, ER u The limit of permissible erosion rate for the tubing, in mm / a; t o The nominal wall thickness of the oil pipe is in mm; tcr denoted as critical wall thickness of the tubing, in mm; T represents the service life, in years.

[0090] Calculating the critical downhole gas erosion velocity: For example, the method for determining the critical downhole gas velocity at which the target well string reaches its ultimate allowable erosion rate is as follows:

[0091] The ultimate permissible erosion rate ER of the injection and production tubing is determined according to formulas (3-6) and (3-7). u ;

[0092] The obtained ER u Substituting into formula (3-5), let ER2 = ER u ;

[0093] The values ​​of the parameters (temperature, particle size, particle concentration, and tubing structure) on the right side of formula (3-5) are determined according to the actual working conditions. This yields the value of the pipe flow velocity v under a single working condition, which is the critical erosion velocity v0 of the downhole gas.

[0094] The critical erosion flow rate of the target well is calculated. For example, the formula for calculating the critical erosion flow rate is as follows:

[0095]

[0096] In the formula, Q0 is the critical erosion flow rate, m 3 / d; v0 is the critical gas velocity, m / s;

[0097] S105. Determine the safety of tubing erosion under the current gas production rate based on the erosion prediction. For example, compare the calculated critical erosion flow rate Q0 with the actual gas production rate Q. If the actual gas production rate Q is less than the critical erosion flow rate Q0, then the current tubing erosion is determined to be in a safe state. If the actual gas production rate Q is greater than or equal to the critical erosion flow rate Q0, then the current gas production rate is determined to be too high and is in an unsafe state. Q should be reduced to Q < Q0.

[0098] Secondly, embodiments of the present invention provide a gas well tubing erosion safety assessment system, such as... Figure 8 As shown, it includes:

[0099] The data acquisition module is used to acquire key parameters of the target well;

[0100] The model building module is used to build mathematical models of gas well tubing erosion.

[0101] The erosion prediction module is used to predict the erosion of the target well string.

[0102] The judgment module is used to determine the safety of tubing erosion under the current gas production rate.

[0103] Thirdly, embodiments of the present invention provide an electronic device, including a memory, a processor, and a computer program stored in the memory and executable in the processor, wherein the processor executes the computer program to implement the steps of the gas well tubing erosion safety assessment method as described above.

[0104] Fourthly, embodiments of the present invention provide a computer-readable storage medium storing a computer program that, when executed by a processor, implements the gas well tubing erosion safety assessment method as described above.

[0105] The above embodiments are preferred embodiments of the present invention, but the embodiments of the present invention are not limited to the above embodiments. Any changes, modifications, substitutions, combinations, or simplifications made without departing from the spirit and principle of the present invention shall be considered equivalent substitutions and shall be included within the protection scope of the present invention.

[0106] Those skilled in the art will understand that embodiments of the present invention can be provided as methods, systems, or computer program products. Therefore, the present invention can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, the present invention can take the form of a computer program product embodied on one or more computer-usable storage media (including, but not limited to, disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0107] This invention is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of the invention. It will be understood that each block of 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, special-purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, generate instructions for implementing the flowchart illustrations and / or block diagrams. Figure 1 One or more processes and / or boxes Figure 1 A device that provides the functions specified in one or more boxes.

[0108] These computer program instructions may also be stored in a computer-readable storage medium that can direct a computer or other programmable data processing device to function in a particular manner, such that the instructions stored in the computer-readable storage medium produce an article of manufacture including instruction means, which are implemented in a process Figure 1 One or more processes and / or boxes Figure 1 The function specified in one or more boxes.

[0109] These computer program instructions may also be loaded onto a computer or other programmable data processing equipment to cause a series of operational steps to be performed on the computer or other programmable equipment to produce a computer-implemented process, thereby providing instructions that execute on the computer or other programmable equipment for implementing the process. Figure 1 One or more processes and / or boxes Figure 1 The steps of the function specified in one or more boxes.

[0110] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A gas well tubing erosion safety evaluation method, characterized in that, The method comprises the following steps: obtaining key parameters of a target well; conducting an erosion test according to the obtained key parameters of the target well and obtaining a test result; constructing a mathematical model of gas well tubing erosion according to the test result; conducting erosion prediction on the tubing string of the target well by using the mathematical model of erosion; judging the safety of tubing erosion under the current gas production capacity according to the erosion prediction.

2. The method of claim 1, wherein, The step of obtaining key parameters of a target well comprises the following steps: obtaining the well depth, operating parameters, tubing string parameters and sand analysis of the target well, wherein the operating parameters include wellhead temperature, wellhead pressure, geothermal gradient and gas production capacity in the operating stage; the tubing string parameters include tubing outer diameter, tubing wall thickness, casing outer diameter and casing wall thickness; the sand analysis includes sand and gravel mass concentration and sand and gravel particle size.

3. The method of claim 1, wherein, The step of conducting an erosion test according to the obtained key parameters of the target well and obtaining a test result comprises the following steps: determining erosion test parameters; conducting sample pretreatment according to the determined test parameters; The pretreated sample is subjected to an erosion test and a test result is obtained, the test result being an erosion test non-dimensional erosion rate calculation formula, the calculation formula being:

4. The method of claim 1, wherein, The step of constructing a mathematical model of gas well tubing erosion according to the test result comprises the following steps: According to the test results of the gas well tubing material erosion under the multi-factor conditions, an erosion mathematical model suitable for the gas well tubing material is established, and the erosion mathematical model can be expressed as:

5. The method of claim 1, wherein, The step of conducting erosion prediction on the tubing string of the target well by using the mathematical model of erosion comprises the following steps: calculating the limit allowable erosion rate of the tubing string of the target well, the critical erosion flow rate of the gas in the well and the critical erosion flow rate of the target well.

6. The method of claim 1, wherein, The step of judging the safety of tubing erosion under the current gas production capacity comprises the following steps: comparing the calculated critical erosion flow rate with the actual gas production capacity, if the actual gas production capacity is less than the critical erosion flow rate, it is judged that the current tubing erosion is in a safe state; if the actual gas production capacity is greater than or equal to the critical erosion flow rate, it is judged that the current gas production capacity is too high, which is in an unsafe state.

7. The method of claim 6, wherein, The critical erosion flow rate calculation formula is:

8. A gas well tubing erosion safety evaluation system, characterized in that, The method comprises the following steps: a data acquisition module for acquiring key parameters of a target well; a model construction module for constructing a mathematical model of gas well tubing erosion; an erosion prediction module for conducting erosion prediction on the tubing string of the target well; a judgment module for judging the safety of tubing erosion under the current gas production capacity.

9. An electronic device, comprising: The computer readable storage medium stores a computer program, and the computer program is executed by the processor to realize the steps of the gas well tubing erosion safety evaluation method according to any one of claims 1-7.

10. A computer-readable storage medium, characterized in that, The computer readable storage medium stores a computer program, and the computer program is executed by the processor to realize the steps of the gas well tubing erosion safety evaluation method according to any one of claims 1-7.

Images