An ultra-flow-rate soft-seal sublayer reconstruction parameter calculation method, system, device and medium

Abstract

The application discloses a kind of superflow soft sealing fine layer reconstruction parameter calculation method, system, equipment and medium, is specifically related to reservoir reconstruction technical field, the point is as follows: the critical velocity when non-target perforation section does not flow is taken as initial value, the competitive liquid absorption driving pressure, liquid absorption capacity and jet momentum of target perforation section are calculated;If the jet momentum calculated is less than liquid absorption capacity, then iteration is updated, and the superflow soft sealing critical velocity is calculated after updating;The first relationship function between the effective impact stress of jet fluid at perforation hole and the stable pore-forming critical velocity, and the second relationship function between the effective tensile strength of reservoir rock mass and the stable pore-forming critical velocity at perforation hole are used to calculate the stable pore-forming critical velocity;Select a maximum value as the minimum fluid flow rate in superflow soft sealing critical velocity and stable pore-forming critical velocity, and calculate the reconstruction parameter of superflow soft sealing fine layer reservoir reconstruction using the minimum fluid flow rate.

Description

Technical Field

[0001] This invention relates to the field of reservoir stimulation technology, specifically to a method, system, equipment, and medium for calculating parameters of ultra-high flow rate soft-seal sub-layer stimulation. Background Technology

[0002] In casing-completed oil and gas wells, perforation is required to establish flow channels between the wellbore and the reservoir. Due to reservoir thickness and heterogeneity, differences in reservoir properties, pressure, and fluid absorption capacity exist between perforated sections. This leads to uneven fluid introduction during conventional acidizing and fracturing operations, resulting in preferential fluid absorption in high-permeability layers and insufficient stimulation of low-permeability layers, making it difficult to achieve balanced reservoir stimulation and full production capacity across the entire wellbore. Furthermore, when using mechanical packers for stratified stimulation, the complex downhole tubing structure makes efficient and reliable sealing of thin interbedded and multi-layered perforated sections difficult, increasing downhole operational risks, construction time, and costs. Therefore, it is necessary to develop a "soft-seal" stratified stimulation method that utilizes high-velocity jets to create localized negative pressure and achieves selective fluid introduction into target perforated sections through fluid entrainment, enabling refined stratified reservoir stimulation.

[0003] Coiled tubing jetting technology uses a spray gun at the end of the coiled tubing to eject fluid in the form of a high-speed jet. This creates a high-speed flow zone between the nozzle and the wellbore. The high-speed jet generates local low pressure and fluid entrainment, allowing the modified fluid to enter the target perforation section, thus achieving stratified modification without mechanical sealing.

[0004] However, existing coiled tubing jetting stimulation technologies mainly rely on experience to select engineering parameters such as the flow rate, lacking system parameter calculation methods based on reservoir properties, reservoir pressure, perforation parameters, fluid dynamics, and rock mechanics characteristics. The main problems are as follows: a lack of a "soft seal" criterion based on differences in reservoir pressure, permeability, and fluid absorption capacity across multiple perforation sections, making it impossible to quantitatively determine the minimum jet velocity required to suppress fluid ingress into non-target perforation sections; a lack of a jetting perforation model considering in-situ reservoir stress, tensile strength, pore pressure, and orifice stress concentration, making it impossible to accurately determine the critical jet velocity required to form stable channels; and existing methods rarely consider the velocity attenuation of high-speed jets from the nozzle to the wellbore, making it difficult to accurately determine the actual flow rate, fluid volume, and sand volume required for construction.

[0005] Therefore, the present invention aims to provide a method, system, device, and medium for calculating parameters of ultra-high flow rate soft seal sub-layer modification, in order to solve the aforementioned related problems. Summary of the Invention

[0006] The purpose of this invention is to solve the problems existing in the prior art and to provide a method for calculating engineering parameters of ultra-high flow rate soft-sealed subdivided reservoir stimulation. This method is used to calculate the pumping parameters for subdivided stimulation after perforation of casing wells in low-permeability carbonate reservoirs, and provides a basis for the design and optimization of subdivided stimulation schemes for casing wells in low-permeability carbonate reservoirs.

[0007] This invention is achieved through the following technical solution:

[0008] A method for calculating parameters of ultra-high flow rate soft seal subdivision modification, the method includes:

[0009] Obtain the critical velocity when no liquid enters the non-target perforation section. Use the critical velocity when no liquid enters the non-target perforation section as the initial value of the critical velocity when the jet fluid enters the perforation section only. Use this initial value to calculate the competitive liquid suction driving pressure, liquid suction capacity and jet flow rate of the target perforation section.

[0010] If the calculated jet flow rate is not greater than the liquid absorption capacity, the initial value is iteratively updated and the calculation is continued after each iteration to obtain the updated competitive liquid absorption driving pressure, liquid absorption capacity and jet flow rate until the updated jet flow rate is greater than the liquid absorption capacity. Only then is the critical velocity of the superfluid soft seal calculated using the updated competitive liquid absorption driving pressure.

[0011] Using the impact coefficient and density of the jet fluid, as well as the stress concentration correction term at the perforation orifice, a first relationship function is constructed between the effective impact stress of the jet fluid at the perforation orifice and the critical velocity for stable perforation. Using the effective stress, permeability dissipation coefficient, permeability of the reservoir rock mass in its in-situ state, and the viscosity of the jet fluid, a second relationship function is constructed between the effective tensile strength of the reservoir rock mass and the critical velocity for stable perforation at the perforation orifice. Using the first and second relationship functions, the critical velocity for stable perforation at the perforation orifice under the critical perforation state is calculated.

[0012] The maximum value between the critical velocity of the superfluid soft seal and the critical velocity of the stable perforation is selected as the minimum fluid velocity at the perforation orifice during the superfluid soft seal sub-layering modification, and the modification parameters of the superfluid soft seal sub-layering reservoir modification are calculated using the minimum fluid velocity.

[0013] Furthermore, the critical velocity when no liquid enters the non-target perforation section is obtained, specifically:

[0014] Obtain the reservoir pressure values ​​corresponding to multiple non-target perforation sections, and extract the maximum value from the reservoir pressure values ​​corresponding to multiple non-target perforation sections as the maximum reservoir pressure value of the non-target perforation section.

[0015] By combining the maximum reservoir pressure with the nozzle outlet pressure, the critical velocity when no liquid enters the non-target perforation section is calculated.

[0016] Furthermore, using this initial value, the competitive liquid-suction driving pressure, liquid-suction capacity, and jet flow rate of the target perforation section are calculated, specifically:

[0017] The local wellbore pressure near the nozzle is calculated using the nozzle outlet pressure and the initial value.

[0018] The fluid flow rate of the target perforation section is calculated by using the local wellbore pressure near the nozzle and the reservoir pressure corresponding to the target perforation section.

[0019] The competitive liquid intake driving pressure of the target perforation section is calculated by using the liquid inflow rate of the target perforation section and the reservoir pressure value corresponding to the target perforation section.

[0020] The liquid absorption capacity of the target perforation section is calculated by using the competitive liquid absorption driving pressure and the flow area of ​​the perforation orifice.

[0021] Using this initial value and the nozzle flow area, the jet flow rate of the target perforation section is calculated.

[0022] Furthermore, the critical velocity of the superfluid soft seal was calculated using the updated competitive suction driving pressure, specifically:

[0023] Based on the updated competitive suction driving pressure, orifice flow area and nozzle flow area of ​​the target perforation section, the critical velocity of the jet fluid when it enters the perforation section is calculated.

[0024] Then, by utilizing the critical velocity of the jet fluid when it enters the perforation section, the competitive suction driving pressure of the final target perforation section is calculated.

[0025] By utilizing the competitive suction driving pressure of the final target perforation section, combined with the orifice flow area and nozzle flow area, the critical velocity of the final jet fluid when it enters the perforation section is calculated.

[0026] The critical velocity of the super-flow soft seal is determined by selecting the maximum value between the critical velocity when no fluid enters the non-target perforation section and the critical velocity when the final jet fluid enters the perforation section.

[0027] Furthermore, if the calculated jet momentum is not greater than the liquid absorption capacity, the initial value is iteratively updated, and the calculation continues after each iteration update, specifically:

[0028] In each iteration of the calculation, if the calculated jet flow rate is not greater than the liquid absorption capacity, a preset velocity threshold is added to the initial value to obtain the updated critical velocity. The updated critical velocity is then used to calculate the competitive liquid absorption driving pressure, liquid absorption capacity, and jet flow rate of the target perforation section, thus obtaining the updated competitive liquid absorption driving pressure, liquid absorption capacity, and jet flow rate.

[0029] Furthermore, the modification parameters include construction discharge rate, liquid volume, and sand volume;

[0030] The stimulation parameters for subdivided reservoir stimulation with ultra-high flow rates were calculated using the minimum fluid velocity method. Specifically:

[0031] The velocity of the ejected fluid after passing through the nozzle is calculated by using the minimum fluid velocity, combined with the distance between the ejected fluid and the nozzle and the nozzle diameter.

[0032] The construction discharge rate is calculated by using the velocity of the jet fluid after passing through the nozzle and the flow area of ​​the nozzle.

[0033] Obtain the preset borehole length for reservoir stimulation, and calculate the borehole construction time using the preset borehole length, sand concentration, and minimum fluid flow rate.

[0034] The amount of construction fluid is calculated using the construction displacement and drilling time.

[0035] The amount of sand is calculated using the amount of construction fluid, sand concentration, and density of the jet fluid.

[0036] This invention also provides a system for calculating parameters of ultra-high flow rate soft seal subdivision layer modification, which is used in the method for calculating parameters of ultra-high flow rate soft seal subdivision layer modification described in any one of the above claims, the system comprising:

[0037] The first calculation module is used to obtain the critical velocity when no liquid enters the non-target perforation section, and uses the critical velocity when no liquid enters the non-target perforation section as the initial value of the critical velocity when the jet fluid enters the perforation section only. The competitive liquid suction driving pressure, liquid suction capacity and jet flow rate of the target perforation section are calculated using the initial value.

[0038] The second calculation module is used to iteratively update the initial value and continue to perform calculations after each iteration update if the calculated jet flow rate is not greater than the liquid absorption capacity, so as to obtain the updated competitive liquid absorption driving pressure, liquid absorption capacity and jet flow rate until the updated jet flow rate is greater than the liquid absorption capacity, and then use the updated competitive liquid absorption driving pressure to calculate the critical velocity of the superfluid soft seal.

[0039] The third calculation module is used to construct a first relationship function between the effective impact stress of the jet fluid at the perforation orifice and the stable critical velocity for perforation by utilizing the impact coefficient and density of the jet fluid and the stress concentration correction term at the perforation orifice; it also constructs a second relationship function between the effective tensile strength of the reservoir rock mass and the stable critical velocity for perforation by utilizing the effective stress, permeability dissipation coefficient, permeability of the reservoir rock mass in its in-situ state and the viscosity of the jet fluid; and finally, it calculates the stable critical velocity for perforation at the perforation orifice when it reaches the critical perforation state using the first and second relationship functions.

[0040] The fourth calculation module is used to select the maximum value between the critical velocity of the ultra-fluidity soft seal and the critical velocity of stable perforation as the minimum fluid velocity at the perforation orifice during ultra-fluidity soft seal sub-layer modification, and to calculate the modification parameters of ultra-fluidity soft seal sub-layer reservoir modification using the minimum fluid velocity.

[0041] The present invention also provides a computer device, including a system memory and a processor, wherein the system memory stores a computer program, and the processor executes the computer program to implement the steps of any of the methods described above.

[0042] The present invention also provides a computer-readable storage medium having a computer program stored thereon, wherein the computer program, when executed by a processor, implements the steps of any of the methods described above.

[0043] The present invention also provides a computer program product containing instructions that, when executed by a cluster of computer devices, cause the cluster of computer devices to perform the method described in any of the preceding claims.

[0044] Compared with the prior art, the present invention has the following advantages and beneficial effects:

[0045] In this invention, the critical velocity required for ultra-high flow rate soft sealing is accurately calculated using the dual constraints of pressure and momentum. By combining the stress concentration and seepage dissipation at the orifice, the critical flow velocity for achieving stable orifice formation is accurately calculated. Finally, the minimum flow velocity at the orifice during the subdivided reservoir stimulation of ultra-high flow rate soft sealing is obtained, providing a more accurate calculation method for optimizing the engineering parameters of this process. Attached Figure Description

[0046] To more clearly illustrate the technical solutions of the exemplary embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly described below. It should be understood that the following drawings only show some embodiments of the present invention and should not be considered as a limitation of the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort. In the drawings:

[0047] Figure 1 This is a flowchart illustrating a method for calculating parameters of a subdivided layer modification of a superfluid soft seal in this embodiment.

[0048] Figure 2 This is a graph showing the relationship between the pressure difference in the perforation section and the critical velocity of the super-flow soft seal in this embodiment.

[0049] Figure 3 This is a graph showing the relationship between reservoir pore pressure and critical flow velocity for stable borehole formation in this embodiment.

[0050] Figure 4 This is a schematic diagram of the module connection of a subdivided layer modification parameter calculation system for ultra-high flow rate soft seal in this embodiment;

[0051] Figure 5 This is a schematic diagram of the structure of a computer device in this embodiment. Detailed Implementation

[0052] The exemplary embodiments of this disclosure are described below with reference to the accompanying drawings, including various details of the embodiments to aid understanding, and should be considered merely exemplary. Therefore, those skilled in the art will recognize that various changes and modifications can be made to the embodiments described herein without departing from the scope of this disclosure. Similarly, for clarity and brevity, descriptions of well-known functions and structures are omitted in the following description.

[0053] In this disclosure, unless otherwise stated, the use of terms such as "first," "second," etc., to describe various elements is not intended to limit the positional, temporal, or importance relationships of these elements; such terms are merely used to distinguish one element from another. In some examples, the first element and the second element may refer to the same instance of that element, while in other cases, based on the context, they may refer to different instances.

[0054] The terminology used in the description of the various examples in this disclosure is for the purpose of describing particular examples only and is not intended to be limiting. Unless the context explicitly indicates otherwise, an element may be one or more unless the number of elements is specifically limited. Furthermore, the term "and / or" as used in this disclosure covers any one of the listed items and all possible combinations thereof.

[0055] Example 1

[0056] See Figure 1 , Figure 1 A flowchart illustrating a method for calculating parameters of ultra-high flow rate soft seal sub-layer modification is shown, wherein the method includes:

[0057] S1: Obtain the critical velocity when no liquid enters the non-target perforation section. Use the critical velocity when no liquid enters the non-target perforation section as the initial value of the critical velocity when the jet fluid enters the perforation section only. Use this initial value to calculate the competitive liquid suction driving pressure, liquid suction capacity and jet flow rate of the target perforation section.

[0058] In this embodiment, when the casing well has a long perforated section, and fluid is required to enter only the target perforated section, the flow pressure inside the wellbore must meet the following requirements. In the formula, Indicates the number of perforation sections, Indicates the target perforation section. This indicates a non-target perforation section; that is, a target perforation section. Corresponding reservoir pressure value Less than the local wellbore pressure value near the nozzle Local wellbore pressure near the nozzle Less than or equal to the maximum reservoir pressure in the non-target perforated section Simultaneously, substituting the calculation function of the local wellbore pressure value near the nozzle into the above inequality, we obtain the critical velocity determination expression when no fluid enters the non-target perforation section: In the formula, The critical velocity, in m / s, is the velocity at which no liquid enters the non-target perforation section. This represents the safety and dimensional adjustment factor, and is dimensionless. This indicates the nozzle outlet pressure value, in MPa. The density of the jet fluid is expressed in kg / m³. 3 Therefore, when no liquid enters the non-target perforation section, the critical velocity calculation function for the non-target perforation section is: .

[0059] It should be noted that, in this embodiment, based on Darcy's law, an analytical model for flow distribution that includes formation flow resistance and perforation flow resistance is established, yielding the... The function for calculating the inlet flow rate of each perforation section is as follows: In the formula, Indicates the first The inlet flow rate of each perforation section, in m 3 / s; This indicates the local wellbore pressure near the nozzle, in MPa. , The intermediate parameters represent the first, second, and third parts, respectively. Formation seepage resistance and perforation flow resistance corresponding to each perforation section;

[0060] Since the influent flow rate calculation function is a nonlinear implicit equation, solving the influent flow rate calculation function and taking the positive root yields the following: Based on this formula, it can be seen that for the target perforation section, when liquid enters the target perforation section i, that is... Then there is For non-target perforation sections, when the flow rate of the remaining non-target perforation sections j approaches 0, i.e. Then there is Therefore, when a cased well has a long perforated section, and fluid is only required to enter the target perforated section, the flow pressure within the wellbore must meet the following requirements. .

[0061] Additionally, it should be noted that in this embodiment, the calculation function for the local wellbore pressure value near the nozzle is as follows: Taking the wellbore as the initial pressure node, after the jet fluid (referring to the high-velocity fluid ejected at high speed from the nozzle) is ejected at high speed from the nozzle, the local wellbore pressure near the nozzle is... In the formula, This indicates the local wellbore pressure near the nozzle, in MPa. Indicates the pressure drop of the ejected fluid, in MPa; In the formula, This represents the flow velocity of the ejected fluid; therefore, the function for calculating the local wellbore pressure near the nozzle is: .

[0062] At the same time, it should also be noted that in this embodiment, the first The process of obtaining the formation seepage resistance and perforation flow resistance corresponding to each perforation section is as follows:

[0063] According to Darcy's principle of permeability, when fluids interact between the reservoir and the wellbore after perforation in a casing well, a series of equivalent flow resistances will be formed in each perforation section. These equivalent flow resistances consist of three parts: radial seepage pressure drop within the reservoir, reservoir contamination pressure drop near the wellbore, and flow pressure drop at the perforation orifice.

[0064] Among them, the radial seepage pressure drop within the reservoir is In the formula, Indicates the first Each perforated section corresponds to a radial flow pressure drop within the reservoir; the reservoir contamination pressure drop near the wellbore is... In the formula, Indicates the first Each perforated section corresponds to the reservoir contamination pressure drop in the near-wellbore zone; the flow pressure drop of the perforated hole is... In the formula, Indicates the first The flow pressure drop corresponding to the perforation orifice in the first perforation section; adding the above three pressure drops together, we obtain the first... Equivalent flow resistance model of a perforation section The equivalent flow resistance model of the perforation section is reorganized to obtain... Finally, extract from the above formula As the first The formation seepage resistance and perforation flow resistance corresponding to each perforation section are used as intermediate parameters for flow rate calculation and competitive liquid absorption drive pressure calculation, thereby obtaining... In the formula, The viscosity of the jet fluid is expressed in mPa·s. Indicates the first Reservoir permeability corresponding to each perforated section, mD; Indicates the first The thickness of each perforation section, in meters (m); Indicates the reservoir supply radius, in meters (m). represents the radius of the wellbore, m; Indicates the first The epidermal coefficient of each perforation segment is dimensionless. This represents the jet attenuation coefficient, which is dimensionless. Indicates the first The flow area of ​​each perforation section, in m² 2 .

[0065] Specifically, in this embodiment, the critical velocity at which no liquid enters the non-target perforation section is obtained is as follows:

[0066] S101: Obtain the reservoir pressure values ​​corresponding to multiple non-target perforation sections, and extract the maximum value from the reservoir pressure values ​​corresponding to multiple non-target perforation sections as the maximum reservoir pressure value in the non-target perforation section.

[0067] Specifically, in this embodiment, one perforation segment is selected as the target perforation segment from multiple perforation segments, and the remaining perforation segments are designated as non-target perforation segments; the reservoir pressure values ​​of the multiple non-target perforation segments are obtained. The maximum value is extracted from the reservoir pressure values ​​corresponding to multiple non-target perforation sections and used as the maximum reservoir pressure value among the multiple non-target perforation sections. .

[0068] S102: Calculate the critical velocity when no liquid enters the non-target perforation section by combining the maximum reservoir pressure value with the nozzle outlet pressure value;

[0069] Specifically, in this embodiment, the safety and dimension adjustment coefficients are obtained. and the density of the jet fluid Based on the maximum reservoir pressure value Nozzle outlet pressure value Safety and dimensional adjustment coefficients and the density of the jet fluid Using the critical velocity calculation function for the non-target perforation section, the critical velocity when no liquid enters the non-target perforation section is calculated. .

[0070] Since there is currently only one critical velocity reference value in the wellbore when no fluid enters the non-target perforation section, the critical velocity when no fluid enters the non-target perforation section will be used as the reference value. The critical velocity of the jet fluid only during liquid inlet in the perforation section The initial value (i.e.) The competitive liquid-suction driving pressure, liquid-suction capacity, and jet flow rate of the target perforation section are calculated using this initial value, as follows:

[0071] S103: Calculate the local wellbore pressure near the nozzle using the nozzle outlet pressure and the initial value;

[0072] Specifically, in this embodiment, based on the nozzle outlet pressure value and initial value Calculation function using local wellbore pressure values ​​near the nozzle The local wellbore pressure value near the nozzle was calculated. .

[0073] S104: Calculate the fluid flow rate of the target perforation section by using the local wellbore pressure near the nozzle and the reservoir pressure corresponding to the target perforation section;

[0074] Specifically, in this embodiment, the viscosity of the ejected fluid is first obtained. Reservoir permeability corresponding to the target perforated section Thickness of the target perforation section reservoir supply radius , wellbore radius Skin coefficient of the target perforation segment Jet attenuation coefficient and the flow area of ​​the orifice in the target perforation section The formation seepage resistance corresponding to the target perforation section was calculated. and perforation flow resistance Then, based on the local wellbore pressure value near the nozzle... Reservoir pressure value corresponding to the target perforated section The function is used to calculate the inlet flow rate of the target perforation section. The inlet flow rate of the target perforation section was calculated. .

[0075] S105: Calculate the competitive liquid intake driving pressure of the target perforation section using the inflow rate of the target perforation section and the reservoir pressure value corresponding to the target perforation section.

[0076] Specifically, in this embodiment, the formation seepage resistance corresponding to the target perforation section is obtained. and perforation flow resistance Based on the inlet flow rate of the target perforation section Reservoir pressure value corresponding to the target perforated section The competitive liquid-suction driving pressure of the target perforation section is calculated using the competitive liquid-suction driving pressure calculation function of the perforation section. .

[0077] It should be noted that, in this embodiment, when a long perforation section exists within the oil and gas well casing, the injected fluid will preferentially enter the perforation section with higher suction drive pressure. Therefore, the calculation function for the competitive suction drive pressure of the target perforation section is: .

[0078] S106: Calculate the liquid absorption capacity of the target perforation section by using the competitive liquid absorption driving pressure and the flow area of ​​the perforation orifice.

[0079] Specifically, in this embodiment, the competitive liquid suction driving pressure is based on the target perforation section. Perforation orifice flow area of ​​the target perforation section The liquid absorption capacity of the target perforation section is calculated using a liquid absorption capacity calculation function.

[0080] It should be noted that, in this embodiment, the function for calculating liquid absorption capacity is specifically as follows: In the formula, Indicates the target perforation section Its ability to absorb liquid.

[0081] S107: Using this initial value and the nozzle flow area, the jet flow rate of the target perforation section is calculated.

[0082] Specifically, in this embodiment, based on the density of the jet fluid Initial value and nozzle flow area The jet flow rate of the target perforation section is calculated using the jet flow rate calculation function.

[0083] It should be noted that, in this embodiment, the jet momentum calculation function is specifically as follows: In the formula, Indicates the target perforation section The jet flow rate, The nozzle flow area is represented in m. 2 .

[0084] S2: If the calculated jet flow rate is not greater than the liquid absorption capacity, the initial value is iteratively updated and the calculation is continued after each iteration to obtain the updated competitive liquid absorption driving pressure, liquid absorption capacity and jet flow rate until the updated jet flow rate is greater than the liquid absorption capacity. Only then is the critical velocity of the superfluid soft seal calculated using the updated competitive liquid absorption driving pressure.

[0085] In this embodiment, in step S1, the critical velocity when no liquid enters the non-target perforation section is used as the initial value of the critical velocity when the jet fluid enters the perforation section only. After calculating the jet flow rate and liquid absorption capacity of the target perforation section, the jet flow rate and liquid absorption capacity of the target perforation section are used to determine whether the jet fluid has completely entered the reservoir through the target perforation section. If the jet flow rate calculated based on the critical velocity when no liquid enters the non-target perforation section is not greater than the corresponding liquid absorption capacity, it means that the jet fluid has not completely entered the reservoir through the target perforation section at this critical velocity. Then, a critical velocity value is added to the critical velocity when no liquid enters the non-target perforation section as the critical velocity when the jet fluid enters the perforation section. The calculation is repeated until the jet flow rate calculated iteratively is greater than the corresponding liquid absorption capacity. Only then is the critical velocity of the superfluid soft seal calculated using the updated competitive liquid absorption driving pressure.

[0086] Specifically, in this embodiment, if the calculated jet flow rate is not greater than the liquid absorption capacity, the initial value is iteratively updated and the calculation continues after each iteration, as follows:

[0087] S201: In each iteration of the calculation, if the calculated jet flow rate is not greater than the liquid absorption capacity, the updated critical velocity is obtained by superimposing a preset velocity threshold on the initial value.

[0088] Specifically, in this embodiment, during each iterative update calculation, if the calculated jet momentum... Not greater than the liquid absorption capacity Then in the initial value Based on this, an additional 10 m / s is added as the critical velocity for the jet fluid to enter the perforation section. That is, the updated critical velocity .

[0089] It should be noted that, in this embodiment, when comparing jet flow rate and liquid absorption capacity, the momentum coefficient also needs to be considered. ,Right now .

[0090] S202: Calculate the competitive liquid-suction driving pressure, liquid-suction capacity, and jet flow rate of the target perforation section using the updated critical velocity, and obtain the updated competitive liquid-suction driving pressure, liquid-suction capacity, and jet flow rate.

[0091] Specifically, in this embodiment, the updated critical velocity is obtained. Then, the updated critical velocity will be... Substitute the values ​​into step S1 for iterative calculation to obtain the updated competitive liquid aspiration driving pressure, liquid aspiration capacity, and jet flow rate.

[0092] After multiple generations of superposition and updates to the critical velocity of the jet fluid when it only enters the perforation section, and after multiple rounds of calculations, until the updated jet flow rate is greater than the liquid absorption capacity, the updated competitive liquid absorption driving pressure is used to calculate the critical velocity of the super-flow soft seal, as follows:

[0093] S203: Based on the updated competitive liquid suction driving pressure, orifice flow area and nozzle flow area of ​​the target perforation section, the critical velocity of the jet fluid when it enters the perforation section is calculated.

[0094] Specifically, in this embodiment, when the jet flow rate is greater than the liquid suction capacity, it means that the jet fluid ejected from the nozzle will flow entirely into the target perforation section; otherwise, it will be "diverted" to other non-target perforation sections. The latest competing liquid suction driving pressure is then obtained. Based on the updated competitive suction-driven pressure of the target perforation section Flow area of ​​the perforation orifice in the target perforation section and nozzle flow area The critical velocity for jet fluid to enter only in the perforation section is calculated using a critical velocity calculation function. .

[0095] It should be noted that, in this embodiment, the critical velocity calculation function for the jet fluid entering only the perforation section is as follows: In the formula, This represents the momentum coefficient, which is dimensionless.

[0096] Specifically, in this embodiment, since the calculation process of the preceding steps S103-S203 involves substituting the set initial value or the critical velocity updated based on the initial value into the calculation function, all of which are reference assumption values, it is necessary to recalculate the critical velocity of the jet fluid entering only in the perforation section in steps S103-S203 to perform closure verification.

[0097] S204: By utilizing the critical velocity of the jet fluid when it enters the perforation section, the competitive suction driving pressure of the final target perforation section is calculated.

[0098] Specifically, in this embodiment, the critical velocity of the jet fluid when it enters the perforation section is utilized. The inlet flow rate of the target perforation section was calculated. ; and then utilize the inlet flow rate of the target perforation section. Reservoir pressure value corresponding to the target perforated section The competitive suction driving pressure of the final target perforation section was calculated. For details, please refer to steps S103-S105, which will not be elaborated on here.

[0099] S205: Utilizing the competitive liquid-driving pressure of the final target perforation section, combined with the orifice flow area. Based on the nozzle flow area, the critical velocity of the final jet fluid when it enters the perforation section is calculated.

[0100] Specifically, in this embodiment, the competitive liquid-driving pressure of the final target perforation section is utilized. and the critical velocity of the jet fluid when it enters the perforation section The liquid absorption capacity and jet flow rate of the target perforation section are calculated, as detailed in steps S106-S107, and will not be elaborated further here. The calculated liquid absorption capacity and jet flow rate of the target perforation section are compared to perform momentum closure verification, as detailed in steps S201-S202, and will not be elaborated further here. Finally, the competitive liquid absorption driving pressure of the target perforation section is utilized. Orifice flow area and nozzle flow area The critical velocity of the final jet fluid when it enters the perforation section is calculated. For details, please refer to step S203, which will not be elaborated here.

[0101] S206: Select the maximum value between the critical velocity when no fluid enters the non-target perforation section and the critical velocity when the final jet fluid enters the perforation section, as the critical velocity for the super-flow soft seal.

[0102] Specifically, in this embodiment, the critical velocity when no liquid enters the non-target perforation section. And the critical velocity of the final jet fluid when it enters the perforation section. Choose the maximum value among them as the critical velocity for the superflow soft seal. , .

[0103] S3: Using the impact coefficient and density of the jet fluid, as well as the stress concentration correction term at the perforation orifice, a first relationship function is constructed between the effective impact stress of the jet fluid at the perforation orifice and the critical velocity for stable perforation. Using the effective stress, permeability dissipation coefficient, permeability of the reservoir rock mass in its in-situ state, and the viscosity of the jet fluid, a second relationship function is constructed between the effective tensile strength of the reservoir rock mass and the critical velocity for stable perforation at the perforation orifice. Using the first and second relationship functions, the critical velocity for stable perforation at the perforation orifice under the critical perforation state is calculated.

[0104] Specifically, in this embodiment, a first relationship function between the effective impact stress of the jet fluid at the perforation orifice and the critical velocity for stable perforation is constructed using the impact coefficient and density of the jet fluid, as well as the stress concentration correction term for the perforation orifice. The specific details are as follows:

[0105] When the jet fluid comes into contact with the reservoir rock at the perforation orifice, the resulting normal impact stress is: In the formula, This represents the normal impact stress of the ejected fluid, expressed in MPa. This represents the impact coefficient, which is dimensionless. The density of the jet fluid is expressed in kg / m³. 3 ; This indicates the critical velocity for stable perforation at the perforation orifice when the perforation state is reached.

[0106] Since the perforation hole is a cylindrical channel, a stress concentration correction term for perforation will be introduced into the perforation hole. The effective impact stress of the ejected fluid at the orifice is obtained as follows: ;

[0107] In summary, the first relationship function between the effective impact stress of the ejected fluid at the perforation orifice and the critical velocity for stable perforation is obtained: .

[0108] Using the effective stress, permeability dissipation coefficient, permeability, and ejected fluid viscosity of the reservoir rock mass in its in-situ state, a second relationship function is constructed between the effective tensile strength of the reservoir rock mass and the critical velocity for stable perforation at the perforation hole. Specifically:

[0109] The effective tensile strength, in-situ minimum principal stress, and pore pressure of the reservoir rock mass are used to obtain the effective stress of the reservoir rock mass in its in-situ state. In the formula, The effective stress of the reservoir rock mass in its in-situ state is expressed in MPa. The tensile strength of the reservoir rock mass is given in MPa. The minimum principal stress in situ, MPa; These are Biot coefficients, dimensionless; Let be the pore pressure of the reservoir rock mass, in MPa. When the injected fluid gradually destabilizes the reservoir rock mass, rapid pressure relief around the borehole will cause seepage dissipation, thereby reducing the accumulation of local stress. At this time, the effective tensile strength of the reservoir rock mass is... In the formula, Effective tensile strength of reservoir rock mass, MPa; Let m be the infiltration dissipation coefficient. Represents reservoir permeability, in mD; Let represent the viscosity of the ejected fluid, in mPa·s; therefore, a second relationship function is obtained between the effective tensile strength of the reservoir rock mass and the critical velocity for stable hole drilling at the perforation orifice: .

[0110] Using the first and second relational functions, the stable critical velocity for perforation at the perforation orifice under critical perforation conditions is calculated as follows:

[0111] When the effective impact stress on the reservoir rock mass is not less than the effective tensile strength of the tensile failure criterion, the reservoir rock mass becomes unstable and fails, thus forming a stable borehole that extends into the deeper reservoir. Therefore, based on the tensile failure criterion of the reservoir rock mass, and considering borehole stress concentration and seepage dissipation, the condition for achieving stable borehole formation at the perforation borehole is as follows: Therefore, based on this condition, if the critical drilling state is reached when the effective impact stress on the reservoir rock mass equals the effective tensile strength of the tensile failure criterion, then... ;

[0112] In summary, to calculate the stable critical velocity for perforation at the perforation orifice when it reaches the critical perforation state, we need to substitute the first and second relations into... Then, after converting to the International System of Units (SI), the critical velocity calculation function for stable perforation at the perforation eye reaching the critical perforation state is obtained: The critical velocity for stable perforation at the perforation orifice, reaching the critical perforation state, is calculated using this calculation function. .

[0113] S4: Select the maximum value between the critical velocity of the ultra-fluidity soft seal and the critical velocity of the stable perforation as the minimum fluid velocity at the perforation orifice during ultra-fluidity soft seal sub-layer modification, and use the minimum fluid velocity to calculate the modification parameters of the ultra-fluidity soft seal sub-layer reservoir modification.

[0114] Specifically, in this embodiment, at the critical velocity of the ultra-high flow rate soft seal... and the critical velocity for stable hole formation Choose the maximum value among them as the minimum fluid velocity at the perforation orifice during the ultra-high flow rate soft seal sub-layer modification. , ;

[0115] It should be noted that, in this embodiment, after obtaining the minimum fluid velocity at the perforation orifice during the ultra-high flow rate soft seal sub-layer modification, it is also necessary to further refine the minimum fluid velocity... Substituting the values ​​into the first and second relational functions, the calculated effective impact stress of the ejected fluid at the perforation hole and the effective tensile strength of the reservoir rock mass are used to verify the conditions for stable hole formation at the perforation hole, thus verifying whether they meet the requirements. Only after verification is the minimum fluid flow rate used. Perform the modification parameter calculation.

[0116] The modification parameters for subdivided reservoir stimulation with ultra-high flow rates were calculated using the minimum fluid velocity method, as follows:

[0117] S401: The velocity of the jet fluid after passing through the nozzle is calculated by using the minimum fluid velocity, combined with the distance between the jet fluid and the nozzle after it is ejected and the nozzle diameter.

[0118] It should be noted that, in this embodiment, the entire process of the jet fluid being ejected at high speed from the nozzle to the orifice is an axial free jet attenuation, i.e. In the formula, This represents the turbulence spread coefficient, which is dimensionless. The velocity of the ejected fluid after passing through the nozzle, in m / s; Let be the nozzle diameter (m); and x be the distance the fluid leaves the nozzle (m). Therefore, the function to calculate the velocity of the ejected fluid after passing through the nozzle is: ;

[0119] Specifically, in this embodiment, based on the minimum fluid flow rate Combined with the distance between the ejected fluid and the nozzle and nozzle diameter The velocity of the ejected fluid after passing through the nozzle is calculated using a velocity calculation function. .

[0120] S402: The construction discharge rate is calculated by using the velocity of the jet fluid after passing through the nozzle and the flow area of ​​the nozzle.

[0121] It should be noted that, in this embodiment, based on the law of conservation of mass, the construction displacement calculation function is as follows: In the formula, This indicates the flow area of ​​the nozzle. This indicates the velocity of the ejected fluid after it passes through the nozzle;

[0122] Specifically, in this embodiment, the construction displacement is calculated using a construction displacement calculation function based on the velocity of the jet fluid after passing through the nozzle and the flow area of ​​the nozzle. .

[0123] S403: Obtain the preset borehole length for reservoir stimulation, and calculate the borehole construction time using the preset borehole length, sand concentration, and minimum fluid flow rate.

[0124] It should be noted that, in this embodiment, when the fluid velocity at the orifice reaches... The hole depth growth model is as follows: In the formula, L is the predetermined drilling length for reservoir stimulation, in meters; t is the drilling time, in seconds; and K is the reservoir lithology coefficient, in seconds per meter. Let be the sand concentration, dimensionless; m be the concentration coefficient, dimensionless; n be the velocity coefficient, dimensionless; then, by integrating the time in the borehole depth growth model, we obtain the borehole construction time t required to reach the predetermined borehole depth. Therefore, the borehole construction time calculation function is: ;

[0125] Specifically, in this embodiment, a preset borehole length for reservoir stimulation is obtained. Based on the preset borehole length, sand concentration, and minimum fluid flow rate, the borehole construction time is calculated using a borehole construction time calculation function. .

[0126] S404: The amount of construction fluid is calculated using the construction displacement and drilling time;

[0127] It should be noted that in this embodiment, the construction fluid volume is calculated using the construction discharge rate and the borehole drilling time; therefore, the construction fluid volume calculation function is: ;

[0128] Specifically, in this embodiment, based on construction discharge volume and drilling construction time The construction fluid volume is calculated using the construction fluid volume calculation function. .

[0129] S405: The amount of sand is calculated using the amount of construction fluid, sand concentration, and density of the jet fluid.

[0130] It should be noted that in this embodiment, the sand quantity is calculated using the construction fluid quantity, sand concentration, and density of the jet fluid; therefore, the sand quantity calculation function is: ;

[0131] Specifically, in this embodiment, based on the construction fluid volume Sand concentration and the density of the jet fluid The sand quantity is calculated using the sand quantity calculation function. .

[0132] Example 2

[0133] In this embodiment, to verify the feasibility of the calculation method provided in Embodiment 1, the following operational scenario example is given:

[0134] Assuming the long perforated section of the casing well is discretized into 3 perforated sections, the obtained reservoir physical property parameters, reservoir contamination parameters, and parameters of each perforated section are shown in Table 1-1.

[0135] Table 1-1 Reservoir physical properties, reservoir contamination parameters, and perforation parameters for three perforations in a casing well.

[0136]

[0137] Obtain nozzle-related parameters: momentum coefficient =1.15; the nozzle diameter is 5mm, 4 in number, to obtain the flow area =7.854×10 -5 m 2 Safety and dimensional adjustment coefficients =2.5; Nozzle outlet pressure =35MPa.

[0138] Obtaining the tensile strength of reservoir rock mass =5MPa; Biot coefficient =0.9; the pore pressure of the reservoir rock mass is equal to the reservoir pressure. = Orifice stress concentration factor =2.0; Impact coefficient =1.0. Based on indoor jetting tests and pressure dissipation tests, the infiltration dissipation coefficient is taken as 1.0. =3.0×10 -10 m.

[0139] Obtaining the turbulence spread coefficient 26; The planned borehole length for reservoir stimulation is L = 5m; the reservoir lithology coefficient is K = 0.5 × 10⁻⁶. -5 s / m; sand concentration =0.06; concentration coefficient m=1.0; velocity coefficient n=2.0.

[0140] (1) Taking the first perforation section as the target perforation section as an example, calculate the critical velocity of the super-flow soft seal under the dual constraint conditions. :

[0141] Step 1: Assuming no fluid enters the non-target perforation section, calculate the critical velocity at which no fluid enters the non-target perforation section, as follows:

[0142] Extract the maximum value from the reservoir pressure values ​​corresponding to the remaining two non-target perforation sections as the maximum reservoir pressure value among the non-target perforation sections. By combining the maximum reservoir pressure with the nozzle outlet pressure, the critical velocity when no fluid enters the non-target perforation section is calculated. =150m / s;

[0143] The second step is to calculate the inlet flow rate of the first perforation section. The details are as follows:

[0144] The critical velocity when no liquid enters the non-target perforation section The critical velocity of the jet fluid only during liquid inlet in the perforation section The initial value (i.e.) =150m / s), calculate the local wellbore pressure near the nozzle. ;

[0145] Utilizing the viscosity of the jet fluid Reservoir permeability corresponding to the target perforated section Thickness of the target perforation section reservoir supply radius , wellbore radius Skin coefficient of the target perforation segment Jet attenuation coefficient and the flow area of ​​the orifice in the target perforation section The formation seepage resistance corresponding to the target perforation section was calculated. and perforation flow resistance : , ;

[0146] Utilizing the local wellbore pressure value near the nozzle Reservoir pressure value corresponding to the target perforated section Combined with intermediate parameters The calculated inlet flow rate for the first perforation section is: ;

[0147] The third step is to conduct momentum verification and calculate the critical velocity of the jet fluid entering only in the perforation section. The details are as follows:

[0148] Inlet flow rate based on target perforation section Reservoir pressure value corresponding to the target perforated section Combined with formation seepage resistance and perforation flow resistance The competitive suction driving pressure of the first perforation section was calculated to be... ;

[0149] Utilizing competitive liquid-driven pressure in the target perforation section and the flow area of ​​the perforation orifice The liquid absorption capacity of the target perforation section is calculated. =98800;

[0150] Using initial values and nozzle flow area Calculate the jet flow rate of the target perforation section. 176715;

[0151] at this time, This indicates that all the ejected fluid entered the reservoir through the first perforation section, based on the updated competitive liquid-driven pressure of the target perforation section. Orifice flow area and nozzle flow area The critical velocity of the jet fluid when it enters the perforation section is calculated. =1202.8 m / s;

[0152] Because the calculations in steps two and three assume... =150m / s, at this point, the newly calculated value needs to be... Substitute, let The closure verification was performed again, and the critical velocity for fluid entry into the perforated section at the wellbore was recalculated. =45.49 m / s;

[0153] The fourth step is to determine the critical velocity when no liquid enters the non-target perforation section. And the critical velocity of the final jet fluid when it enters the perforation section. By selecting a maximum value among the options, the critical velocity for the super-flow soft seal in the first perforation section under the dual constraints of pressure and momentum is obtained. .

[0154] Based on the above calculations, the critical velocity of the ultra-high flow rate soft seal is mainly affected by the critical velocity at which no liquid enters the non-target perforation section. Based on this constraint, a correlation was established between the pressure difference ΔPr in the perforation section and the critical velocity of the ultra-high flow rate soft seal. Relationship curves, such as Figure 2 As shown in the curve, the greater the pressure difference in the perforation section, the stronger the flow competition between the target perforation section and the non-target perforation section, and the higher the critical velocity of the ultra-high flow rate soft seal required to achieve selective liquid injection.

[0155] (2) Calculate the critical velocity required to achieve stable hole formation at the perforation hole. :

[0156] The first step is to construct a first relationship function between the effective impact stress of the jet fluid at the perforation orifice and the critical velocity for stable perforation by utilizing the impact coefficient and density of the jet fluid, as well as the stress concentration correction term at the perforation orifice. At this point, the effective impact stress of the super-velocity fluid at the orifice... The unit is Pa;

[0157] The second step is to utilize the effective tensile strength of the reservoir rock mass. Minimum Principal Stress in Place And the pore pressure of the reservoir rock mass, to obtain the effective stress of the reservoir rock mass in situ. MPa; This value indicates that, considering the combined effects of minimum principal stress, tensile strength, and pore pressure in situ, the rock resistance that needs to be overcome to form a stable channel in the first perforation section is 5.97 MPa.

[0158] Considering seepage dissipation around the perforation site, a second relationship function is constructed between the effective tensile strength of the reservoir rock mass and the critical velocity for stable perforation at the perforation hole. At this point, the effective tensile strength of the reservoir The unit has been converted to Pa;

[0159] The third step is that when the effective impact stress on the reservoir rock mass equals the effective tensile strength of the tensile failure criterion, the critical drilling state is reached, and then... ,at this time After calculating the formula and taking the positive value, the critical flow velocity for achieving stable perforation at the perforation orifice is obtained. 78.58 m / s.

[0160] Based on the above calculations, the pore pressure of the reservoir rock mass was established. Critical flow rate for stable pore formation Relationship curves, such as Figure 3 As shown in the curve, the higher the reservoir pore pressure, the lower the effective rock damage stress, and the lower the critical velocity for high-velocity pore formation required for the jet to form stable channels.

[0161] (3) Calculate the minimum fluid velocity at the orifice during the stimulation of the subdivided reservoir with high flow rate soft sealing. The details are as follows:

[0162] The first step is to compare the critical velocity of the ultra-high flow rate soft seal. and the critical flow rate for stable pore formation ,get ;

[0163] To achieve a stable critical flow velocity for perforation at the perforation orifice Recalculate and The effective impact stress of the superfluid at the orifice was obtained. 22.5 MPa, effective tensile strength of the reservoir 6.36 MPa; at this time, This indicates that when A speed of 150 m / s is sufficient to ensure stable borehole formation.

[0164] (4) Calculate the construction displacement, liquid volume, and sand volume for the high-flow-rate soft-seal sub-layer reservoir stimulation, as follows:

[0165] Let the distance x after the fluid leaves the nozzle be r. w The nozzle speed is then calculated. 181.2 m / s; the calculated drilling time t = 740.8 s; the calculated drilling displacement Q = 0.853 m³ / s. 3 / min; calculate the construction fluid volume 10.5 m 3 The amount of construction sand was calculated. 0.632 t;

[0166] In summary, the engineering parameters for achieving high-velocity soft sealing and layered reservoir stimulation in the first perforation section are as follows: Discharge rate of 0.853 m³ / s. 3 / min, construction fluid volume 10.5 m 3 The amount of sand used in the construction was 0.632 t.

[0167] Repeating the above calculations, the engineering parameters for the high-velocity soft-seal sub-layer reservoir stimulation in the second and third perforation sections can be obtained, as shown in Table 1-2:

[0168] Table 1-2 Engineering parameters for each perforation section of ultra-high flow rate soft-sealed sub-layered reservoir stimulation

[0169]

[0170] Example 3

[0171] See Figure 4 The present invention also provides a calculation system for ultra-high flow rate soft seal subdivision layer modification parameters. This system is used in the calculation method for ultra-high flow rate soft seal subdivision layer modification parameters described in any one of the above claims. The system includes:

[0172] The first calculation module 100 is used to obtain the critical velocity when no liquid enters the non-target perforation section, and uses the critical velocity when no liquid enters the non-target perforation section as the initial value of the critical velocity when the jet fluid enters the perforation section only, and uses the initial value to calculate the competitive liquid suction driving pressure, liquid suction capacity and jet flow rate of the target perforation section.

[0173] The second calculation module 200 is used to iteratively update the initial value and continue to perform calculations after each iteration update if the calculated jet flow rate is not greater than the liquid absorption capacity, so as to obtain the updated competitive liquid absorption driving pressure, liquid absorption capacity and jet flow rate until the updated jet flow rate is greater than the liquid absorption capacity, and then use the updated competitive liquid absorption driving pressure to calculate the critical velocity of the superfluid soft seal.

[0174] The third calculation module 300 is used to construct a first relationship function between the effective impact stress of the jet fluid at the perforation orifice and the stable critical velocity for perforation by utilizing the impact coefficient and density of the jet fluid and the stress concentration correction term for perforation orifice; and to construct a second relationship function between the effective tensile strength of the reservoir rock mass and the stable critical velocity for perforation at the perforation orifice by utilizing the effective stress, permeability dissipation coefficient, permeability of the reservoir rock mass in its in-situ state and the viscosity of the jet fluid; and to calculate the stable critical velocity for perforation at the perforation orifice when it reaches the critical state for perforation by using the first and second relationship functions.

[0175] The fourth calculation module 400 is used to select the maximum value between the critical velocity of the ultra-flow soft seal and the critical velocity of the stable perforation as the minimum fluid velocity at the perforation orifice during the ultra-flow soft seal sub-layer modification, and to calculate the modification parameters of the ultra-flow soft seal sub-layer reservoir modification using the minimum fluid velocity.

[0176] It should be noted that the modules in the system of Embodiment 2 correspond to the steps in the method of Embodiment 1. The steps in the method of Embodiment 1 have been described in detail in Embodiment 1, and the module content in the system will not be described in detail in this Embodiment 2.

[0177] Example 3

[0178] See Figure 5 This embodiment also provides a computer device, including a system memory 1005 and a processor 1001. The system memory 1005 stores a computer program, and the processor 1001 executes the computer program to implement the steps of any of the methods described above.

[0179] It should be noted that the processor 1001 is used to execute the steps in the above method embodiments according to the instructions in the program code. Alternatively, when the processor 1001 executes the computer program, it implements the functions of each module / unit in the above system / device embodiments.

[0180] Specifically, in this embodiment, the computer program can be divided into one or more modules / units, which are stored in the system memory 1005 and executed by the processor 1001 to complete this application. The one or more modules / units can be a series of computer program instruction segments capable of performing specific functions, which describe the execution process of the computer program in the terminal device.

[0181] The terminal device can be a desktop computer, laptop, handheld computer, or cloud server, etc. The terminal device may include, but is not limited to, a processor 1001 and a system memory 1005. Those skilled in the art will understand that this does not constitute a limitation on the terminal device; it may include more or fewer components than shown in the figures, or a combination of certain components, or different components. For example, the terminal device may also include an input / output device 1003, a network access device 1002, a bus 1006, etc.

[0182] The processor 1001 can be a Central Processing Unit (CPU), or other general-purpose processors, digital signal processors (DSPs), application-specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. A general-purpose processor can be a microprocessor or any conventional processor.

[0183] System memory 1005 can be an internal storage unit of the terminal device, such as a hard drive or RAM. System memory 1005 can also be a storage device 1004 of the terminal device, such as an external hard drive, SmartMedia Card (SMC), Secure Digital (SD) card, or FlashCard. Furthermore, system memory 1005 can include both internal storage units and storage device 1004. System memory 1005 is used to store computer programs and other programs and data required by the terminal device. System memory 1005 can also be used to temporarily store data that has been output or will be output.

[0184] Those skilled in the art will clearly understand that, for the sake of convenience and brevity, the specific working processes of the systems and units described above can be referred to the corresponding processes in the foregoing method embodiments, and will not be repeated here.

[0185] Example 4

[0186] This embodiment provides a computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the steps of any of the methods described above.

[0187] The computer-readable storage medium may be, for example, but not limited to, an electrical, magnetic, optical, electromagnetic, infrared, or semiconductor system, device, or any combination thereof. More specific examples of computer-readable storage media (a non-exhaustive list) include: an electrical connection having one or more wires, a portable computer disk, a hard disk, random access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM), registers, hard disks, optical fibers, compact disc read-only memory (CD-ROM), optical storage devices, magnetic storage devices, or any suitable combination thereof, or any other form of computer-readable storage medium in the art.

[0188] An exemplary storage medium is coupled to a 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 within an application-specific integrated circuit (ASIC). In embodiments of the invention, the computer-readable storage medium can be any tangible medium containing or storing a program that can be used by or in conjunction with an instruction execution system, system, or device.

[0189] Example 5

[0190] This embodiment also provides a computer program product containing instructions that, when executed by a cluster of computer devices, cause the cluster of computer devices to perform the method described in Embodiment 1.

[0191] The specific embodiments described above further illustrate the purpose, technical solution, and beneficial effects of the present invention. It should be understood that the above description is only a specific embodiment of the present invention and is not intended to limit the scope of protection of the present invention. 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 method for calculating parameters of ultra-high flow rate soft seal subdivision modification, characterized in that, The methods include: Obtain the critical velocity when no liquid enters the non-target perforation section. Use the critical velocity when no liquid enters the non-target perforation section as the initial value of the critical velocity when the jet fluid enters the perforation section only. Use this initial value to calculate the competitive liquid suction driving pressure, liquid suction capacity and jet flow rate of the target perforation section. If the calculated jet flow rate is not greater than the liquid absorption capacity, the initial value is iteratively updated and the calculation is continued after each iteration to obtain the updated competitive liquid absorption driving pressure, liquid absorption capacity and jet flow rate until the updated jet flow rate is greater than the liquid absorption capacity. Only then is the critical velocity of the superfluid soft seal calculated using the updated competitive liquid absorption driving pressure. Using the impact coefficient and density of the jet fluid, as well as the stress concentration correction term at the perforation orifice, a first relationship function is constructed between the effective impact stress of the jet fluid at the perforation orifice and the critical velocity for stable perforation. Using the effective stress, permeability dissipation coefficient, permeability of the reservoir rock mass in its in-situ state, and the viscosity of the jet fluid, a second relationship function is constructed between the effective tensile strength of the reservoir rock mass and the critical velocity for stable perforation at the perforation orifice. Using the first and second relationship functions, the critical velocity for stable perforation at the perforation orifice under the critical perforation state is calculated. The maximum value between the critical velocity of the superfluid soft seal and the critical velocity of the stable perforation is selected as the minimum fluid velocity at the perforation orifice during the superfluid soft seal sub-layering modification, and the modification parameters of the superfluid soft seal sub-layering reservoir modification are calculated using the minimum fluid velocity.

2. The method for calculating parameters of ultra-high flow rate soft seal sub-layer modification according to claim 1, characterized in that, The critical velocity for obtaining the non-target perforation section without liquid inflow is as follows: Obtain the reservoir pressure values ​​corresponding to multiple non-target perforation sections, and extract the maximum value from the reservoir pressure values ​​corresponding to multiple non-target perforation sections as the maximum reservoir pressure value of the non-target perforation section. By combining the maximum reservoir pressure with the nozzle outlet pressure, the critical velocity when no liquid enters the non-target perforation section is calculated.

3. The method for calculating parameters of ultra-high flow rate soft seal sub-layer modification according to claim 1, characterized in that, Using this initial value, the competitive liquid-suction driving pressure, liquid-suction capacity, and jet flow rate of the target perforation section are calculated as follows: The local wellbore pressure near the nozzle is calculated using the nozzle outlet pressure and the initial value. The fluid flow rate of the target perforation section is calculated by using the local wellbore pressure near the nozzle and the reservoir pressure corresponding to the target perforation section. The competitive liquid intake driving pressure of the target perforation section is calculated by using the liquid inflow rate of the target perforation section and the reservoir pressure value corresponding to the target perforation section. The liquid absorption capacity of the target perforation section is calculated by using the competitive liquid absorption driving pressure and the flow area of ​​the perforation orifice. Using this initial value and the nozzle flow area, the jet flow rate of the target perforation section is calculated.

4. The method for calculating parameters of ultra-high flow rate soft seal sub-layer modification according to claim 1, characterized in that, The critical velocity of the superflow soft seal was calculated using the updated competitive suction drive pressure, specifically: Based on the updated competitive suction driving pressure, orifice flow area and nozzle flow area of ​​the target perforation section, the critical velocity of the jet fluid when it enters the perforation section is calculated. Then, by utilizing the critical velocity of the jet fluid when it enters the perforation section, the competitive suction driving pressure of the final target perforation section is calculated. By utilizing the competitive suction driving pressure of the final target perforation section, combined with the orifice flow area and nozzle flow area, the critical velocity of the final jet fluid when it enters the perforation section is calculated. The critical velocity of the super-flow soft seal is determined by selecting the maximum value between the critical velocity when no fluid enters the non-target perforation section and the critical velocity when the final jet fluid enters the perforation section.

5. The method for calculating parameters of ultra-high flow rate soft seal sub-layer modification according to claim 1, characterized in that, If the calculated jet flow rate is not greater than the liquid absorption capacity, the initial value is iteratively updated, and the calculation continues after each iteration update, specifically: In each iteration of the calculation, if the calculated jet flow rate is not greater than the liquid absorption capacity, a preset velocity threshold is added to the initial value to obtain the updated critical velocity. The updated critical velocity is then used to calculate the competitive liquid absorption driving pressure, liquid absorption capacity, and jet flow rate of the target perforation section, thus obtaining the updated competitive liquid absorption driving pressure, liquid absorption capacity, and jet flow rate.

6. The method for calculating parameters of ultra-high flow rate soft seal sub-layer modification according to claim 1, characterized in that, The modification parameters include construction discharge volume, liquid volume, and sand volume; The stimulation parameters for subdivided reservoir stimulation with ultra-high flow rates were calculated using the minimum fluid velocity method. Specifically: The velocity of the ejected fluid after passing through the nozzle is calculated by using the minimum fluid velocity, combined with the distance between the ejected fluid and the nozzle and the nozzle diameter. The construction discharge rate is calculated by using the velocity of the jet fluid after passing through the nozzle and the flow area of ​​the nozzle. Obtain the preset borehole length for reservoir stimulation, and calculate the borehole construction time using the preset borehole length, sand concentration, and minimum fluid flow rate. The amount of construction fluid is calculated using the construction displacement and drilling time. The amount of sand is calculated using the amount of construction fluid, sand concentration, and density of the jet fluid.

7. A parameter calculation system for ultra-high flow rate soft seal sub-layer modification, characterized in that, This system is used in the method for calculating parameters of ultra-high flow rate soft seal subdivision modification as described in any one of claims 1-6, wherein the system comprises: The first calculation module is used to obtain the critical velocity when no liquid enters the non-target perforation section, and uses the critical velocity when no liquid enters the non-target perforation section as the initial value of the critical velocity when the jet fluid enters the perforation section only. The competitive liquid suction driving pressure, liquid suction capacity and jet flow rate of the target perforation section are calculated using the initial value. The second calculation module is used to iteratively update the initial value and continue to perform calculations after each iteration update if the calculated jet flow rate is not greater than the liquid absorption capacity, so as to obtain the updated competitive liquid absorption driving pressure, liquid absorption capacity and jet flow rate until the updated jet flow rate is greater than the liquid absorption capacity, and then use the updated competitive liquid absorption driving pressure to calculate the critical velocity of the superfluid soft seal. The third calculation module is used to construct a first relationship function between the effective impact stress of the jet fluid at the perforation orifice and the stable critical velocity for perforation by utilizing the impact coefficient and density of the jet fluid and the stress concentration correction term at the perforation orifice; it also constructs a second relationship function between the effective tensile strength of the reservoir rock mass and the stable critical velocity for perforation by utilizing the effective stress, permeability dissipation coefficient, permeability of the reservoir rock mass in its in-situ state and the viscosity of the jet fluid; and finally, it calculates the stable critical velocity for perforation at the perforation orifice when it reaches the critical perforation state using the first and second relationship functions. The fourth calculation module is used to select the maximum value between the critical velocity of the ultra-fluidity soft seal and the critical velocity of stable perforation as the minimum fluid velocity at the perforation orifice during ultra-fluidity soft seal sub-layer modification, and to calculate the modification parameters of ultra-fluidity soft seal sub-layer reservoir modification using the minimum fluid velocity.

8. A computer device comprising a system memory and a processor, wherein the system memory stores a computer program, characterized in that, When the processor executes the computer program, it implements the steps of the method according to any one of claims 1 to 6.

9. A computer-readable storage medium having a computer program stored thereon, characterized in that, When the computer program is executed by a processor, it implements the steps of the method described in any one of claims 1 to 6.

10. A computer program product containing instructions, characterized in that, When the instruction is executed by a cluster of computer devices, the cluster of computer devices causes the cluster of computer devices to perform the method as described in any one of claims 1 to 6.

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