A method and device for designing a scale removal scale of a reservoir around a gas well, a computer device and a storage medium

Abstract

The application discloses a kind of gas well well reservoir scale of scale removal design method, device, computer equipment and storage medium, belong to gas well well reservoir scale of scale removal field.The application provides a kind of gas well well reservoir scale of scale removal design method, in turn, calculate the critical scale formation pressure under reservoir temperature, calculate the well reservoir scale formation radius under critical scale formation pressure, calculate the appropriate scale removal scale under well reservoir scale formation radius, realize scientific, quantitative prediction gas well well reservoir scale formation range, design scale removal scale, improve gas well reservoir scale removal effect.Compared with the traditional gas well scale removal scale depends on experience judgment, the application realizes the optimal design of scale removal effect and construction cost.The application provides a kind of gas well well reservoir scale of scale removal device, includes the specific module of completing the above work method.The application provides a kind of computer equipment and storage medium of gas well well reservoir scale of scale removal design method, for realizing the specific steps of the above work method.

Description

Technical Field

[0001] This invention belongs to the field of descaling of gas well perimeter reservoirs, and in particular, it relates to a design method, apparatus, computer equipment, and storage medium for the scale of descaling of gas well perimeter reservoirs. Background Technology

[0002] Natural gas is a clean resource, and its share of total primary energy consumption is increasing year by year. For gas wells, scaling and blockage are common phenomena; scaling problems have been reported in major gas fields in China's Ordos, Sichuan, and Tarim basins. Gas well scaling typically leads to fluctuating and decreased wellhead oil pressure, reduced production, and even well shutdown.

[0003] Common types of scale in gas wells include calcium carbonate and calcium sulfate, which are generally distributed in the wellbore and surrounding reservoir. These are typically removed using acid injection or chelation-based deblocking systems. Currently, the design of deblocking scale for surrounding reservoirs relies on experience, but research on "scale radius prediction" and "deblocking scale design" is unclear. Early experience suggests that small-scale, low-volume injection systems can remove blockages within the wellbore. However, for surrounding reservoirs, the pore and fracture volumes of scale are generally much larger than the wellbore volume. Designing a deblocking scale that is too small results in incomplete deblocking, poor (or even ineffective) deblocking, and a short effective period, preventing full release of production capacity. Conversely, designing a deblocking scale that is too large leads to "over-design," resulting in limited improvement in effectiveness while increasing additional operating costs. Summary of the Invention

[0004] The purpose of this invention is to overcome the shortcomings of the prior art and provide a design method, apparatus, computer equipment, and storage medium for the scale of descaling of gas well perimeter reservoirs.

[0005] To achieve the above objectives, the present invention employs the following technical solution:

[0006] A method for designing the scale of peri-wellbore reservoir descaling in gas wells includes the following steps:

[0007] Step 1: Calculate the critical scaling pressure P of the reservoir at a given reservoir temperature T using the modified Oddo-Tomson saturation index formula. c ;

[0008] Step 2: Based on the reservoir critical scaling pressure P c Calculate the radius R of scale formation in the reservoir around the well. c ;

[0009] Step 3: Based on the wellbore reservoir scaling radius R c Calculate the volume V of the unblocking fluid;

[0010] Weigh out the unblocking fluid according to the dosage V, and use it for descaling the gas well perimeter reservoir.

[0011] Furthermore, step 1 specifically involves:

[0012] (101) Assuming the critical scaling pressure at reservoir temperature T is P0, the CO2 fugacity coefficient is calculated using equation (6) based on reservoir temperature T and critical scaling pressure P0.

[0013]

[0014] Obtain the content of CO2 in the oil-gas-water mixture system under ground conditions Daily water production Q under standard conditions w Daily gas production Q under standard conditions g Based on the content of CO2 in the oil-gas-water mixture system under ground conditions Daily water production Q under standard conditions w Daily gas production Q under standard conditions g and CO2 fugacity coefficient The CO2 content in the gas phase under P0 and T conditions is calculated using equation (7).

[0015]

[0016] The temperature coefficient A1 is calculated using formula (3) based on the reservoir temperature T:

[0017] A1=7.3+0.01519(1.8T+32)-1.64×10 -6 (1.8T+32) 2 (3)

[0018] Obtain the ionic strength μ in the formation water, and calculate the ionic strength coefficient A2 based on μ using equation (4):

[0019] A2 = -3.334μ 0.5 +1.431μ (4);

[0020] Obtain the calcium ion concentration C (Ca) in formation water 2+ ) and the bicarbonate ion content (C(HCO3)) in formation water - Based on the calcium ion concentration C(Ca) in formation water 2+ ), Bicarbonate ion content (C(HCO3)) in formation water - CO2 fugacity coefficient and the content of CO2 in the gas phase under P and T conditions Calculate the proportionality coefficient A0 using equation (2):

[0021]

[0022] Based on the proportionality coefficient A0, temperature coefficient A1, ionic strength coefficient A2 and critical scaling pressure P0, P1 is calculated using equation (1);

[0023]

[0024] In the formula, T is the reservoir temperature, °C; C(Ca 2+ ) represents the calcium ion concentration in formation water, in mol / L; C(HCO3) - () represents the bicarbonate ion content in formation water, in mol / L; This is the CO2 fugacity coefficient, which is dimensionless. The content of CO2 in a CO2-oil-gas-water mixture under surface conditions, in %; Q represents the CO2 content in the gas phase under P and T conditions, expressed as a percentage. w The daily water production under standard conditions, in m 3 Q g The daily gas production under standard conditions, in m 3 μ represents the ionic strength of the formation water, in mol / L.

[0025] (102) Compare P0 and P1. If the relative error between the two is greater than the preset value, take P1 as the input value and repeat step (101) to calculate P2.

[0026] (103) Repeat steps (101) and (102) until the relative error between the two calculations of P is less than or equal to the preset value. At this point, the latest calculated P is the critical scaling pressure P at the reservoir temperature. c .

[0027] Furthermore, the ionic strength μ in the formation water is:

[0028]

[0029] c i Let z be the concentration of ion i in the formation water, in mol / L; i Let i be the valence of an i-th ion in the formation water, dimensionless.

[0030] Furthermore, the relative error is the ratio of the difference between the two calculations of P to the P calculated in the next calculation;

[0031] The preset value is 1%.

[0032] Furthermore, step 2 specifically involves:

[0033] (201) Determine the bottom pressure P of the gas well wf With the reservoir critical scaling pressure P c The size, if the bottom pressure P of the gas well wf Greater than or equal to the reservoir critical scaling pressure Pc At this time, scaling will not occur in the reservoir;

[0034] If the bottom of the gas well is P wf Less than the reservoir critical scaling pressure P c At this point, the scale formation area within the reservoir is the scale radius R from the bottom of the well to the well perimeter. c .

[0035] Furthermore, the scaling radius R c for:

[0036]

[0037] In the formula, R c Where P is the reservoir scaling radius, in meters; e P represents the deep reservoir pressure, in MPa; wf The bottom hole flowing pressure is in MPa; r e r is the reservoir boundary radius, m; w Let be the radius of the wellbore, in meters (m).

[0038] Furthermore, step 3 specifically involves:

[0039]

[0040] In the formula, V represents the scale and unblocking solution volume, m 3 φ represents the average porosity of the reservoir, which is dimensionless; R c λ is the reservoir scaling radius, in meters; h is the average reservoir thickness, in meters; λ is the proportion of the effective gas-producing section thickness in the reservoir, dimensionless.

[0041] A design device for the scale of descaling around a gas well reservoir includes a reservoir critical scaling pressure acquisition module, a well-around reservoir scaling radius acquisition module, and a deblocking fluid dosage acquisition module.

[0042] The reservoir critical scaling pressure acquisition module is used to calculate the reservoir critical scaling pressure P at a given reservoir temperature T using the modified Oddo-Tomson saturation index formula. c ;

[0043] The wellbore reservoir scaling radius acquisition module is used to obtain the scaling radius based on the reservoir critical scaling pressure P. c Calculate the radius R of scale formation in the reservoir around the well. c ;

[0044] The unblocking fluid dosage acquisition module is used to obtain the dosage based on the wellbore reservoir scaling radius R. c Calculate the amount of unblocking fluid V.

[0045] A computer device includes a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the computer program to implement the steps of the design method for the scale of descaling of the gas well peri-well reservoir according to the present invention.

[0046] A computer-readable storage medium storing a computer program that, when executed by a processor, implements the steps of the method for designing the scale of descaling of the gas well perimeter reservoir according to the present invention.

[0047] Compared with the prior art, the present invention has the following beneficial effects:

[0048] This invention provides a method for designing the scale of wellbore descaling in gas wells. It sequentially calculates the critical scaling pressure at reservoir temperature, the scale radius around the wellbore at the critical scaling pressure, and the appropriate unblocking scale based on the scale radius. This allows for the scientific and quantitative prediction of the scale range around the gas well, enabling the design of the unblocking scale and improving the descaling effect. Compared to traditional methods that rely on experience to determine the unblocking scale, this invention achieves optimal design in terms of both unblocking effectiveness and construction cost.

[0049] This invention provides an apparatus for large-scale descaling of gas well perimeter reservoirs, comprising specific modules for performing the above-mentioned working method.

[0050] This invention provides a computer device and storage medium for designing the scale of descaling around a gas well reservoir, used to implement the specific steps of the above-mentioned working method. Attached Figure Description

[0051] Figure 1 This is a schematic diagram showing the extent of scaling in the reservoir around a gas well.

[0052] Figure 2 The result is the calculated scale radius around the gas well reservoir.

[0053] Figure 3 This is a graph showing the relationship between the perimeter scale radius and the bottom-hole flowing pressure of a gas well.

[0054] Figure 4 A graph showing the relationship between the scale of gas well unclogging and the radius of scale buildup around the well.

[0055] Figure 5 This is a schematic diagram of the design device for the scale of descaling of gas well perimeter reservoirs according to the present invention;

[0056] Figure 6 This is a schematic diagram of a computer device in an embodiment of the present invention. Detailed Implementation

[0057] To enable those skilled in the art to better understand the present invention, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of the present invention.

[0058] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this invention are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of the invention described herein can be implemented in orders other than those illustrated or described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover a non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0059] The present invention will now be described in further detail with reference to the accompanying drawings:

[0060] This invention discloses a method for designing the scale removal scale of gas well perimeter reservoirs, which can realize the assessment of the scale radius of gas well perimeter reservoirs and the quantitative design of the scale removal scale.

[0061] A method for designing the scale of peri-wellbore reservoir descaling in gas wells includes the following steps:

[0062] Step 1: Calculate the critical scaling pressure P of the reservoir at a given reservoir temperature T using the modified Oddo-Tomson saturation index formula. c The calculation steps are as follows:

[0063] ① Assuming the critical scaling pressure at reservoir temperature T is P0, calculate equations (2) to (6) sequentially to obtain A0, A1, A2, and Substituting the value into equation (1), we get P1.

[0064] ② Compare P0 and P1. If the difference between them is greater than 1%, use P1 as the input value and repeat step ① to obtain P2.

[0065] ③ Repeat steps ① and ② until the difference between the two calculations of P is less than 1%. At this point, the latest calculated P is the critical scaling pressure P at the reservoir temperature. c .

[0066]

[0067]

[0068] A1=7.3+0.01519(1.8T+32)-1.64×10 -6 (1.8T+32) 2 (3)

[0069] A2 = -3.334μ 0.5 +1.431μ (4)

[0070]

[0071]

[0072]

[0073] In the formula, P0 is the critical scaling pressure, MPa, below which scaling occurs in the system; T is the reservoir temperature, °C; C(Ca 2+ ) represents the calcium ion concentration in formation water, in mol / L; C(HCO3) - () represents the bicarbonate ion content in formation water, in mol / L; This is the CO2 fugacity coefficient, which is dimensionless. The content of CO2 in a CO2-oil-gas-water mixture under surface conditions, in %; Q represents the CO2 content in the gas phase under P0 and T conditions, expressed as a percentage (%). w The daily water production under standard conditions, in m 3 Q g The daily gas production under standard conditions, in m 3 μ represents the ionic strength of the formation water, in mol / L; c i Let z be the concentration of ion i in the formation water, in mol / L; i Let i be the valence of an i-th ion in the formation water, dimensionless.

[0074] Step 2: Calculate the critical scaling pressure P of the reservoir. c Radius R of the perimeter of the reservoir after downhole c The specific method is as follows:

[0075] ①If the bottom pressure P of the gas well wf Greater than or equal to the reservoir critical scaling pressure P c At this time, scaling will not occur in the reservoir;

[0076] ②If the bottom P of the gas well wf Less than the reservoir critical scaling pressure P c At this point, the scale buildup area within the reservoir extends from the bottom of the well to a certain radius R around the well. cThe scaling radius is calculated using equation (8):

[0077]

[0078] In the formula, R c Where P is the reservoir scaling radius, in meters; e P represents the deep reservoir pressure, in MPa; wf The bottom hole flowing pressure is in MPa; r e r is the reservoir boundary radius, m; w Let be the radius of the wellbore, in meters (m).

[0079] A schematic diagram for determining the scale area in gas wells and a calculation of the scale radius are provided below. Figure 1 and Figure 2 , Figure 1 This is a schematic diagram showing the extent of scaling in the reservoir around a gas well. Figure 2 This is the calculated result of the scale radius around the gas well reservoir.

[0080] Step 3: Calculate the scale radius R of the gas well reservoir. c The specific method for using the following unblocking fluid dosage V is as follows:

[0081]

[0082] In the formula, V represents the scale and unblocking solution volume, m 3 φ represents the average porosity of the reservoir, which is dimensionless; R c λ is the reservoir scaling radius, in meters; h is the average reservoir thickness, in meters; λ is the proportion of the effective gas-producing section thickness in the reservoir, dimensionless.

[0083] Example

[0084] Gas well X belongs to a typical ultra-deep, high-temperature, and high-pressure gas field. The well depth is 5000m, the reservoir pressure is 72MPa, the reservoir temperature is 138℃, and the daily gas production is 100,000 m³. 3 Daily water production 1m 3 The formation water salinity is 162,485 mg / L, and the natural gas methane content is 98.3%. The specific composition data of the gas and water are as follows:

[0085] Table 1. Air and water component data

[0086]

[0087] Table 2 Reservoir Data

[0088]

[0089]

[0090] Step 1: Calculate the critical scaling pressure P corresponding to a reservoir temperature of 138℃ in well X. cThe calculation results are shown in Table 3. The critical scaling pressure P was calculated. c It is 63.9 MPa.

[0091] Table 3. Air and water component data

[0092]

[0093] Step 2: Calculate the scale radius of the reservoir in well X. The relationship between the scale radius of the reservoir around the well and different bottomhole flowing pressures is shown in [reference needed]. Figure 3 ,from Figure 3 It can be seen that the lower the bottom-hole flowing pressure, the larger the radius of scale formation in the reservoir around the well. Figure 4 A graph showing the relationship between the scale of gas well unclogging and the radius of wellbore scaling, from... Figure 4 As can be seen, the scale of unblocking also increases with the increase of the congestion radius.

[0094] See Figure 5 , Figure 5 This is a schematic diagram of the design device for the scale of descaling around a gas well reservoir according to the present invention. The device includes a reservoir critical scaling pressure acquisition module, a wellbore reservoir scaling radius acquisition module, and a unblocking fluid dosage acquisition module. The reservoir critical scaling pressure acquisition module is used to calculate the reservoir critical scaling pressure P at a given reservoir temperature T using the modified Oddo-Tomson saturation index formula. c The wellbore perimeter reservoir scaling radius acquisition module is used to obtain the scaling radius based on the reservoir critical scaling pressure P. c Calculate the radius R of scale formation in the reservoir around the well. c The unblocking fluid dosage acquisition module is used to obtain the dosage based on the wellbore scale radius R. c Calculate the amount of unblocking fluid V.

[0095] In one embodiment, a computer device is provided, which may be a server, and its internal structure diagram may be as follows: Figure 6 As shown, the computer device includes a processor, memory, network interface, and database connected via a system bus. The processor provides computing and control capabilities. The memory includes non-volatile storage media and internal memory. The non-volatile storage media stores the operating system, computer programs, and database. The internal memory provides an environment for the operation of the operating system and computer programs in the non-volatile storage media. When the computer program is executed by the processor, it describes a design method for achieving scaled-down gas well peri-wellbore reservoir descaling.

[0096] In one embodiment, a computer device is provided, including a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the computer program, it performs the following steps: Step 1: Calculate the critical fouling pressure P of the reservoir at a given reservoir temperature T using the modified Oddo-Tomson saturation index formula. c Step 2: Based on the reservoir critical scaling pressure P c Calculate the radius R of scale formation in the reservoir around the well. c Step 3: Based on the wellbore reservoir scaling radius R c Calculate the amount of unblocking fluid V.

[0097] In one embodiment, a computer-readable storage medium is provided having a computer program stored thereon, the computer program performing the following steps when executed by a processor: Step 1, calculating the critical fouling pressure P of the reservoir at a given reservoir temperature T using the modified Oddo-Tomson saturation exponent formula. c Step 2: Based on the reservoir critical scaling pressure P c Calculate the radius R of scale formation in the reservoir around the well. c Step 3: Based on the wellbore reservoir scaling radius R c Calculate the amount of unblocking fluid V.

[0098] Those skilled in the art will understand that all or part of the processes in the methods of the above embodiments can be implemented by a computer program instructing related hardware. The computer program can be stored in a non-volatile computer-readable storage medium. When executed, the computer program can include the processes of the embodiments of the above methods. Any references to memory, storage, databases, or other media used in the embodiments provided by this invention can include non-volatile and / or volatile memory. Non-volatile memory can include read-only memory (ROM), programmable ROM (PROM), electrically programmable ROM (EPROM), electrically erasable programmable ROM (EEPROM), or flash memory. Volatile memory can include random access memory (RAM) or external cache memory. By way of illustration and not limitation, RAM is available in various forms, such as static RAM (SRAM), dynamic RAM (DRAM), synchronous DRAM (SDRAM), dual data rate SDRAM (DDRSDRAM), enhanced SDRAM (ESDRAM), synchronous link DRAM (SLDRAM), RAMbus direct RAM (RDRAM), direct memory bus dynamic RAM (DRDRAM), and RAMbus dynamic RAM (RDRAM), etc.

[0099] The above content is only for illustrating the technical concept of the present invention and should not be construed as limiting the scope of protection of the present invention. Any modifications made to the technical solution based on the technical concept proposed in this invention shall fall within the scope of protection of the claims of this invention.

Claims

1. A method for designing the scale of peri-wellbore reservoir descaling in a gas well, characterized in that, Includes the following steps: Step 1: Calculate the given reservoir temperature using the modified Oddo-Tomson saturation index formula. T Below the critical fouling pressure of the reservoir P c ; Step 2: Based on the critical scaling pressure of the reservoir P c Calculate the radius of scale formation in the reservoir around the well. R c ; Step 3: Based on the wellbore reservoir scaling radius R c Calculate the amount of unblocking fluid needed V ; According to the amount of unblocking fluid used V Weigh out the unblocking fluid and use it for descaling the gas well's perimeter reservoir. ； Step 1 is as follows: (101) Assuming reservoir temperature T The lower critical scaling pressure is P 0, based on reservoir temperature T and critical scaling pressure P 0. Calculate the CO2 fugacity coefficient using equation (6) ; （6） Obtain the content of CO2 in the oil-gas-water mixture system under ground conditions Daily water production under standard conditions Q w Daily gas production under standard conditions Q g Based on the content of CO2 in the oil-gas-water mixture system under ground conditions Daily water production under standard conditions Q w Daily gas production under standard conditions Q g and CO2 fugacity coefficient CO2 is calculated using equation (7) P 0 、T CO2 content in the gas phase under certain conditions : （7）； Based on reservoir temperature T Calculate the temperature coefficient using formula (3) A 1: （3） Obtain the ion intensity μ in the formation water, and calculate the ion intensity coefficient based on μ using equation (4). A 2: （4）； Obtaining calcium ion concentration in formation water C (Ca 2+ ) and bicarbonate ion content in formation water W (HCO3 - Based on the calcium ion concentration in formation water C (Ca 2+ ), bicarbonate ion content in formation water W (HCO3 - CO2 fugacity coefficient and CO2 in P, T CO2 content in the gas phase under certain conditions Calculate the proportionality coefficient using equation (2) A 0: （2）； Based on the proportional coefficient A 0. Temperature coefficient A 1. Ionic strength coefficient A 2 and critical scaling pressure P 0, calculate using equation (1) P 1; （1）； In the formula, T The reservoir temperature is expressed in °C. C (Ca 2+ () represents the calcium ion concentration in formation water, in mol / L; W (HCO3 - () represents the bicarbonate ion content in formation water, in mol / L; This is the CO2 fugacity coefficient, which is dimensionless. The content of CO2 in a CO2-oil-gas-water mixture under surface conditions, % For CO2 in P, T CO2 content in the gas phase under the given conditions, % Q w The daily water production under standard conditions, in m 3 ; Q g The daily gas production under standard conditions, in m 3 μ represents the ionic strength of the formation water, in mol / L. (102) Comparison P 0 and P 1. If the relative error between the two is greater than the preset value, then... P 1 is the input value. Repeat step (101) to calculate the result. P 2; (103) Repeat steps (101) and (102) until the two calculations are completed. P The relative error is less than or equal to the preset value, at which point the latest calculated value is... P Critical scaling pressure at reservoir temperature P c .

2. The method for designing the scale of peri-wellbore reservoir descaling according to claim 1, characterized in that, The ionic strength μ in the formation water is: （5） c i The concentration of ion i in the formation water is given in mol / L. z i Let i be the valence of an i-th ion in the formation water, dimensionless.

3. The method for designing the scale of peri-wellbore reservoir descaling according to claim 1, characterized in that, The relative error is calculated in two separate steps. P The ratio of the difference to the P calculated in the next step; The preset value is 1%.

4. The method for designing the scale of peri-wellbore reservoir descaling according to claim 1, characterized in that, Step 2 is as follows: (201) Determine the bottom flow pressure of the gas well P wf Critical scaling pressure of the reservoir P c The size, if the bottom flow pressure of the gas well P wf Greater than or equal to the reservoir critical scaling pressure P c At this time, scaling will not occur in the reservoir; If the bottom of the gas well P wf Less than the critical scaling pressure of the reservoir P c At this point, the scale buildup area within the reservoir is the radius of the scale buildup from the bottom of the well to the well perimeter. R c .

5. The method for designing the scale of peri-wellbore reservoir descaling according to claim 4, characterized in that, Scale radius R c for: （8） In the formula, R c Let be the reservoir scaling radius, in meters. P e The pressure in the deep reservoir is MPa. P wf The bottom hole flowing pressure is in MPa. r e Let be the reservoir boundary radius, in meters. r w Let be the radius of the wellbore, in meters (m).

6. The method for designing the scale of peri-wellbore reservoir descaling according to claim 1, characterized in that, Step 3 specifically involves: （9） In the formula, V For the scale and unblocking solution scale, m 3 φ represents the average porosity of the reservoir, which is dimensionless. R c Let be the reservoir scaling radius, in meters. h The average reservoir thickness is in meters (m). λ represents the proportion of the effective gas-producing section of the reservoir, which is dimensionless.

7. A design device for scale removal of gas well perimeter reservoir, characterized in that, This includes modules for obtaining critical scaling pressure in reservoirs, obtaining the scale radius of reservoirs around wells, and obtaining the amount of unblocking fluid used. The reservoir critical scaling pressure acquisition module is used to calculate a given reservoir temperature using the modified Oddo-Tomson saturation index formula. T Below the critical fouling pressure of the reservoir P c ; The wellbore reservoir scaling radius acquisition module is used to obtain the scaling radius based on the reservoir critical scaling pressure. P c Calculate the radius of scale formation in the reservoir around the well. R c ; The unblocking fluid dosage acquisition module is used to obtain the dosage based on the wellbore scale radius. R c Calculate the amount of unblocking fluid needed V； The specific execution method of the reservoir critical scaling pressure acquisition module is as follows: (101) Assuming reservoir temperature T The lower critical scaling pressure is P 0, based on reservoir temperature T and critical scaling pressure P 0. Calculate the CO2 fugacity coefficient using equation (6) ; （6） Obtain the content of CO2 in the oil-gas-water mixture system under ground conditions Daily water production under standard conditions Q w Daily gas production under standard conditions Q g Based on the content of CO2 in the oil-gas-water mixture system under ground conditions Daily water production under standard conditions Q w Daily gas production under standard conditions Q g and CO2 fugacity coefficient CO2 is calculated using equation (7) P 0 、T CO2 content in the gas phase under certain conditions : （7）； Based on reservoir temperature T Calculate the temperature coefficient using formula (3) A 1: （3） Obtain the ion intensity μ in the formation water, and calculate the ion intensity coefficient based on μ using equation (4). A 2: （4）； Obtaining calcium ion concentration in formation water C (Ca 2+ ) and bicarbonate ion content in formation water W (HCO3 - Based on the calcium ion concentration in formation water C (Ca 2+ ), bicarbonate ion content in formation water W (HCO3 - CO2 fugacity coefficient and CO2 in P, T CO2 content in the gas phase under certain conditions Calculate the proportionality coefficient using equation (2) A 0: （2）； Based on the proportional coefficient A 0. Temperature coefficient A 1. Ionic strength coefficient A 2 and critical scaling pressure P 0, calculate using equation (1) P 1; （1）； In the formula, T The reservoir temperature is expressed in °C. C (Ca 2+ () represents the calcium ion concentration in formation water, in mol / L; W (HCO3 - () represents the bicarbonate ion content in formation water, in mol / L; This is the CO2 fugacity coefficient, which is dimensionless. The content of CO2 in a CO2-oil-gas-water mixture under surface conditions, % For CO2 in P, T CO2 content in the gas phase under the given conditions, % Q w The daily water production under standard conditions, in m 3 ; Q g The daily gas production under standard conditions, in m 3 μ represents the ionic strength of the formation water, in mol / L. (102) Comparison P 0 and P 1. If the relative error between the two is greater than the preset value, then... P 1 is the input value. Repeat step (101) to calculate the result. P 2; (103) Repeat steps (101) and (102) until the two calculations are completed. P The relative error is less than or equal to the preset value, at which point the latest calculated value is... P Critical scaling pressure at reservoir temperature P c .

8. A computer device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that, When the processor executes the computer program, it implements the steps of the method for designing the scale of wellbore reservoir descaling as described in any one of claims 1-6.

9. A computer-readable storage medium storing a computer program, characterized in that, When the computer program is executed by the processor, it implements the steps of the method for designing the scale of wellbore reservoir descaling as described in any one of claims 1-6.

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