Method and device for analyzing temporary plugging efficiency of multi-cluster fracturing in horizontal wells

Abstract

The invention proposes a method and device for analyzing temporary plugging efficiency of multi-cluster fracturing of a horizontal well, and relates to the technical field of oil and natural gas extraction. The method comprises: in sequence, in the first stage of sand fracturing, and in each subsequent stage of sand fracturing, when a temporary plugging process needs to be implemented, the following steps are cyclically executed until the last stage of sand fracturing is completed: determining a first pressure value when a fracturing curve is stable; determining an initial perforation hole friction resistance according to the number of perforation holes in a wellbore, a perforation hole diameter, a fracturing fluid density and a construction displacement; determining a second pressure value when a fracturing curve is stable; determining the perforation hole friction resistance after temporary plugging according to the initial perforation hole friction resistance, the first pressure value and the second pressure value; determining the number of perforation holes that are not plugged after temporary plugging according to the perforation hole friction resistance after temporary plugging, the construction displacement, the fracturing fluid density and the perforation hole diameter; determining the temporary plugging efficiency according to the number of perforation holes that are not plugged after temporary plugging, the number of perforation holes in the wellbore and the number of temporary plugging balls.

Description

Technical Field

[0001] The invention relates to the technical field of oil and natural gas exploitation, and in particular to a method and a device for analyzing temporary plugging efficiency of multi-cluster fracturing of horizontal wells. Background Art

[0002] This section is intended to provide a background or context to the embodiments of the invention recited in the claims. No admission is made that the description herein is prior art by inclusion in this section.

[0003] Horizontal well segmented transformation technology is a key technology for the development of unconventional reservoirs. In order to increase the reservoir transformation volume and increase the contact area between artificial fractures and reservoirs, multi-cluster perforation is often used in horizontal well transformation, that is, multiple perforation sections are arranged in the same transformation layer section, and each perforation section is fully opened by increasing the construction displacement and other measures, thereby increasing the single well production of tight oil and gas wells. However, a large number of well practices have shown that multi-cluster fracturing has the problem of limited opening degree of perforation clusters. Therefore, relevant technologies need to be adopted to ensure that multiple clusters in the horizontal well section are fully opened.

[0004] Temporary plugging technology is a key technology to improve the degree of multi-cluster pressure opening within a segment. Its basic principle is to put temporary plugging balls into the fracturing section of the bridge plug segment to plug the perforated holes, and increase the construction net pressure on the basis of the effective pressure bearing of the temporary plugging balls to press open new clusters, so as to achieve the purpose of fracture diversion within the segment. During the fracturing construction process, the sand-carrying fluid at a high construction displacement will quickly grind the holes, causing the holes to expand to varying degrees. At the same time, the temporary plugging balls are subjected to complex forces and difficult to predict their running trajectories under the action of different liquid types and construction displacements. The temporary plugging balls put in cannot all be sealed and effectively plugged. Therefore, the temporary plugging efficiency of the temporary plugging balls needs to be effectively evaluated. At present, the existing technology for the analysis of temporary plugging efficiency of multi-cluster fracturing in horizontal wells only studies the optimization of temporary plugging ball type, size and dosage in terms of mechanism, and cannot quantitatively characterize the temporary plugging efficiency of temporary plugging balls during actual fracturing construction. Summary of the invention

[0005] In order to solve the problems existing in the prior art, the present invention proposes a method and device for analyzing temporary plugging efficiency of multi-cluster fracturing in horizontal wells; the method and device can quantitatively characterize the temporary plugging efficiency of temporary plugging balls during actual fracturing construction.

[0006] In an embodiment of the present invention, a method for analyzing the temporary plugging efficiency of multi-cluster fracturing in a horizontal well is proposed, comprising:

[0007] When temporary plugging is required in the first stage of sand fracturing and in each subsequent stage of sand fracturing, the following steps are performed cyclically until the last stage of sand fracturing is completed:

[0008] Determine the first pressure value when the fracturing curve is stable before temporary plugging;

[0009] Determine the initial perforation friction according to the number of perforations in the wellbore, the perforation diameter, the density of the fracturing fluid and the operation displacement;

[0010] Determine the second pressure value when the fracturing curve is stable after temporary plugging;

[0011] Determine the perforation hole friction resistance after temporary plugging according to the initial perforation hole friction resistance, the first pressure value and the second pressure value;

[0012] Determine the number of perforations that remain unplugged after temporary plugging based on the friction resistance of the perforations after temporary plugging, the operation displacement, the density of the fracturing fluid and the diameter of the perforations;

[0013] The temporary plugging efficiency is determined based on the number of perforations that are not plugged after temporary plugging, the number of perforations in the wellbore and the number of temporary plugging balls.

[0014] In an embodiment of the present invention, a device for analyzing the temporary plugging efficiency of multi-cluster fracturing in a horizontal well is provided, comprising:

[0015] A trigger module is used to sequentially trigger the following modules to execute in a loop when a temporary plugging process is required for sand fracturing in the first stage and in each subsequent stage until the sand fracturing in the last stage is completed;

[0016] A data recording module before temporary plugging, used to determine the first pressure value when the fracturing curve is stable before temporary plugging;

[0017] The initial hole friction calculation module is used to determine the initial hole friction according to the number of holes in the wellbore, the hole diameter, the density of the fracturing fluid and the operation displacement;

[0018] A data recording module after temporary plugging, used to determine a second pressure value when the fracturing curve is stable after temporary plugging;

[0019] A perforation friction calculation module after temporary plugging, used to determine the perforation friction after temporary plugging according to the initial perforation friction, the first pressure value and the second pressure value;

[0020] The module for calculating the number of unplugged holes is used to determine the number of unplugged holes after temporary plugging according to the friction resistance of the perforated holes after temporary plugging, the operation displacement, the density of the fracturing fluid and the diameter of the perforated holes;

[0021] The temporary plugging efficiency calculation module is used to determine the temporary plugging efficiency according to the number of perforations that are not plugged after temporary plugging, the number of perforations in the wellbore and the number of temporary plugging balls.

[0022] In an embodiment of the present invention, a computer device is proposed, 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, a method for analyzing the temporary plugging efficiency of multi-cluster fracturing in horizontal wells is implemented.

[0023] In an embodiment of the present invention, a computer-readable storage medium is provided. The computer-readable storage medium stores a computer program. When the computer program is executed by a processor, a method for analyzing temporary plugging efficiency of multi-cluster fracturing of horizontal wells is implemented.

[0024] A computer program product is provided in an embodiment of the present invention. The computer program product includes a computer program. When the computer program is executed by a processor, a method for analyzing temporary plugging efficiency of multi-cluster fracturing of horizontal wells is implemented.

[0025] The method and device for analyzing the temporary plugging efficiency of multi-cluster fracturing in horizontal wells proposed in the embodiments of the present invention can solve the problem that the current actual fracturing construction cannot quantitatively characterize the temporary plugging efficiency of multi-cluster fracturing in horizontal wells. By obtaining the first pressure value when the fracturing curve is stable before temporary plugging, the number of perforations in the wellbore, the diameter of the perforations, the density of the fracturing fluid, the construction displacement and the second pressure value when the fracturing curve is stable after temporary plugging, the initial perforation friction resistance and the perforation friction resistance after temporary plugging are determined, and the number of perforations that are not plugged after temporary plugging is calculated, and then the temporary plugging efficiency is quantitatively characterized, so as to achieve quantitative analysis of the temporary plugging efficiency of multi-cluster fracturing in horizontal wells, which is of great significance for improving the accuracy of fracturing schemes, guiding the precise optimization and real-time adjustment of temporary plugging parameters, and reducing temporary plugging costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0027] Figure 1 1 is a flow chart of a method for analyzing temporary plugging efficiency of multi-cluster fracturing in horizontal wells according to an embodiment of the present invention;

[0028] Figure 2 2 is a specific example diagram of a method for analyzing temporary plugging efficiency of multi-cluster fracturing in horizontal wells according to an embodiment of the present invention;

[0029] Figure 3 This is a specific embodiment diagram of the temporary plugging efficiency analysis process of multi-cluster fracturing in horizontal wells in an embodiment of the present invention;

[0030] Figure 4 Schematic diagram of a device for analyzing temporary plugging efficiency of multi-cluster fracturing in horizontal wells according to an embodiment of the present invention;

[0031] Figure 5 Schematic diagram of a computer device in an embodiment of the present invention. DETAILED DESCRIPTION

[0032] To make the purpose, technical solution and advantages of the embodiments of the present invention more clear, the embodiments of the present invention are further described in detail below in conjunction with the accompanying drawings. Here, the exemplary embodiments of the present invention and their descriptions are used to explain the present invention, but are not intended to limit the present invention.

[0033] The term "and / or" herein only describes an association relationship, indicating that three relationships may exist. For example, A and / or B may represent the following three situations: A exists alone, A and B exist at the same time, and B exists alone. In addition, the term "at least one" herein represents any combination of at least two of any one or more of a plurality of. For example, including at least one of A, B, and C may represent including any one or more elements selected from the set consisting of A, B, and C.

[0034] In the description of this specification, the terms "include", "including", "have", "contain", etc. are all open terms, which mean including but not limited to. The descriptions with reference to the terms "one embodiment", "a specific embodiment", "some embodiments", "for example", etc. mean that the specific features, structures or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present application. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures or characteristics described may be combined in a suitable manner in any one or more embodiments or examples. The order of steps involved in each embodiment is used to schematically illustrate the implementation of the present application, and the order of steps is not limited and can be appropriately adjusted as needed.

[0035] The principle and spirit of the present invention are explained in detail below with reference to several representative embodiments of the present invention.

[0036] Figure 1 FIG. 1 is a flow chart of a method for analyzing the temporary plugging efficiency of multi-cluster fracturing in horizontal wells according to an embodiment of the present invention. Figure 1 As shown, the method includes:

[0037] When temporary plugging is required in the first stage of sand fracturing and in each subsequent stage of sand fracturing, the following steps are performed cyclically until the last stage of sand fracturing is completed:

[0038] S1, determining the first pressure value when the fracturing curve is stable before temporary plugging;

[0039] S2, determining the initial perforation friction according to the number of perforations in the wellbore, the perforation diameter, the density of the fracturing fluid and the operation displacement;

[0040] S3, determining a second pressure value when the fracturing curve is stable after temporary plugging;

[0041] S4, determining the friction resistance of the perforation hole after temporary plugging according to the initial perforation hole friction resistance, the first pressure value and the second pressure value;

[0042] S5, determining the number of perforations that are not plugged after temporary plugging according to the friction resistance of the perforations after temporary plugging, the operation displacement, the density of the fracturing fluid and the diameter of the perforations;

[0043] S6, determining the temporary plugging efficiency according to the number of perforations that are not plugged after temporary plugging, the number of perforations in the wellbore, and the number of temporary plugging balls.

[0044] Depend on Figure 1 It can be seen from the process shown that the embodiment of the present invention determines the initial perforation hole friction resistance and the perforation hole friction resistance after temporary plugging by obtaining the first pressure value when the fracturing curve is stable before temporary plugging, the number of perforations in the wellbore, the perforation hole diameter, the fracturing fluid density, the construction displacement and the second pressure value when the fracturing curve is stable after temporary plugging, calculates the number of perforations that are not plugged after temporary plugging, and then determines the temporary plugging efficiency, so as to realize quantitative analysis of the temporary plugging efficiency of multi-cluster fracturing in horizontal wells.

[0045] In the embodiment of the present invention, a temporary plugging process needs to be implemented in the first stage of the sand fracturing process. In the subsequent stages of the sand fracturing process, it is necessary to determine whether to implement the temporary plugging process. When implementing the temporary plugging process, the first pressure value when the fracturing curve is stable before temporary plugging is first determined. According to the number of perforations in the wellbore, the diameter of the perforations, the density of the fracturing fluid and the construction displacement, the initial perforation friction resistance is determined. After the temporary plugging ball is put into the wellbore, the temporary plugging ball is pumped to the perforations in the wellbore for plugging. The second pressure value when the fracturing curve is stable after temporary plugging is determined. According to the initial perforation friction resistance, the first pressure value and the second pressure value, the perforation friction resistance after temporary plugging is determined. According to the perforation friction resistance after temporary plugging, the construction displacement, the density of the fracturing fluid and the perforation diameter, the number of perforations that are not plugged after temporary plugging is determined, and then the temporary plugging efficiency is determined. The embodiment of the present invention realizes quantitative analysis of the temporary plugging efficiency of multi-cluster fracturing in horizontal wells, which can improve the accuracy of fracturing schemes and guide the accurate optimization of temporary plugging parameters.

[0046] In order to explain the above-mentioned method for analyzing temporary plugging efficiency of multi-cluster fracturing in horizontal wells more clearly, each step is described in detail below.

[0047] Figure 2 1 is an example diagram of a method for analyzing the temporary plugging efficiency of multi-cluster fracturing in horizontal wells according to an embodiment of the present invention. Figure 2 Explain each of the above steps.

[0048] In one embodiment of the present invention, reference Figure 2For the above S1, when the accumulated sand volume in the wellbore reaches a predetermined value, the sand addition is stopped, and after all the sand in the wellbore is displaced to the outside of the wellbore by using medium-viscosity fracturing fluid, the first pressure value when the fracturing curve is stable before temporary plugging is determined; wherein the fracturing curve is a curve of the relationship between the pump pressure and the construction displacement recorded on the ground and the time changes.

[0049] In one embodiment of the present invention, reference Figure 2 , determine the first pressure value when the fracturing curve is stable before temporary plugging according to the following steps:

[0050] (1) Pumping bridge plug and perforating gun: Use cable pumping to pump bridge plug and perforating gun of designed size into the well, so that the bridge plug is set at the designed position; use perforating gun to perforate according to the designed parameters and carry out fracturing operation;

[0051] (2) Put in the bridge plug ball and inject low-viscosity fracturing fluid, acid, or high-viscosity fracturing fluid: After putting in the bridge plug ball of designed size, use a low construction displacement (1-2m 3 / min) injection 5-10m 3 After low-viscosity fracturing fluid (5-30mPa·s), the designed amount of acid (10-15% hydrochloric acid solution) is injected at the same low construction displacement; then the low-viscosity fracturing fluid is replaced again and the construction displacement is increased to 5-6m 3 / min to speed up the migration of the bridge plug in the wellbore; when the accumulated liquid volume reaches 0.6-0.8 times the wellbore volume, reduce the construction displacement to 1-2m 3 / min, so that the bridge plug ball can be smoothly sealed when it reaches the bridge plug position to seal the previous or previous fracturing section;

[0052] (3) Low-viscosity fracturing fluid sanding operation: When the cumulative fluid volume reaches 1.1-1.2 times the wellbore volume, high-viscosity fracturing fluid (100-120 mPa·s) is used to create main fractures in the reservoir, and the construction displacement is gradually increased to the designed maximum value; when the high-viscosity fracturing fluid reaches the designed dosage, the high-viscosity fracturing fluid is switched to low-viscosity fracturing fluid (5-30 mPa·s), and the sanding operation is started; the sanding mode is 2-3 stage continuous or segment plug sanding;

[0053] (4) Displacement with medium-viscosity fracturing fluid: When the accumulated sand volume reaches 50% to 65% of the designed sand volume, stop adding sand and switch the fracturing fluid from low viscosity to medium viscosity (30-60 mPa·s). Use 1.2-1.5 times the wellbore volume of medium-viscosity fracturing fluid to displace all the sand in the wellbore into the reservoir, and record the first pressure value P1 when the fracturing curve is stable before temporary plugging.

[0054] In specific implementation, the first pressure value P1 when the fracturing curve is stable before temporary plugging is determined, and the fluctuation of P1 pressure does not exceed ±0.3MPa. The value of P1 will directly affect the calculation accuracy of the friction resistance of the perforation holes after subsequent temporary plugging. Therefore, when taking the value, it is required that the stable pressure value fluctuates within the range of 1-2 minutes and does not exceed ±0.3MPa.

[0055] In one embodiment of the present invention, with respect to the above S2, the initial perforation hole friction resistance is determined according to the following formula based on the number of perforations in the wellbore, the perforation hole diameter, the density of the fracturing fluid and the operation displacement:

[0056]

[0057] Among them, Δp perfs1 represents the initial perforation friction, MPa; ρ represents the fracturing fluid density, kg / m 3 ; Q represents the construction displacement, m 3 / min; N1 is the number of perforation holes in the wellbore, pieces; D is the diameter of the perforation hole, m; C d It indicates the flow coefficient set according to the perforation hole diameter and fracturing fluid viscosity.

[0058] In one embodiment of the present invention, reference Figure 2 For the above S3, a certain number of temporary plugging balls are put in, and medium viscosity fracturing fluid is used to pump the temporary plugging balls (30-60mPa·s). When pumping, 5-6m 3 / min operation displacement to inject 0.5-0.7 times the wellbore volume of medium viscosity fracturing fluid, and reduce the operation displacement to 0.5-1m 3 / min, inject 1-1.2 times the volume of wellbore fracturing fluid cumulatively, and after the temporary plugging ball is stably sealed in the blasthole, increase the construction displacement step by step to the highest design value, and record the second pressure value P2 when the fracturing curve is stable after temporary plugging. The purpose of using medium-viscosity fracturing fluid to pump the temporary plugging ball and reduce the construction displacement is to ensure that the temporary plugging ball is stably sealed in the blasthole to the greatest extent. If low-viscosity fracturing fluid and large construction displacement are used, it is easy to cause the migration trajectory of the temporary plugging ball in the wellbore to be unstable and unable to be stably sealed in the blasthole.

[0059] During specific implementation, the number of temporary plugging balls dropped into the wellbore is 1 / 3-1 / 2 times the number of perforation holes in the wellbore. The particle size of the temporary plugging balls is determined according to the diameter of the perforation holes. The selection principle is: the difference between the particle size of the temporary plugging balls and the diameter of the perforation holes is between 3-5mm. On this basis, temporary plugging balls of a single particle size or a combination of temporary plugging balls of multiple particle sizes can be selected.

[0060] In specific implementation, the second pressure value P2 when the fracturing curve is stable after temporary plugging is recorded, that is, the P2 pressure fluctuation does not exceed ±0.3MPa. The size of P2 will directly affect the calculation accuracy of the perforation friction resistance after subsequent temporary plugging. Therefore, when taking the value, the stable pressure value is required to fluctuate within ±0.3MPa within the range of 1-2 minutes.

[0061] In specific implementation, when the displacement is increased step by step to the designed maximum value, the liquid volume shall not exceed 0.8-1 times the wellbore volume; in order to ensure the calculation accuracy of the friction resistance of the perforation holes, it is necessary to ensure that the morphology and parameters of the cracks before and after temporary plugging remain basically unchanged. Therefore, in order to prevent excessive expansion of cracks during the process of increasing the construction displacement, it is necessary to reduce the amount of fracturing fluid used as much as possible, and it is stipulated that it shall not exceed 0.8-1 times the wellbore volume. If it is greater than this value, it will cause excessive extension of the cracks and affect the accuracy of the results.

[0062] In one embodiment of the present invention, with respect to the above S4, the friction resistance of the perforation holes after temporary plugging is determined according to the following formula based on the initial perforation hole friction resistance, the first pressure value and the second pressure value:

[0063] Δp perfs2 =Δp perfs1 +(P2-P1);

[0064] Among them, Δp perfs2 Indicates the friction resistance of the perforation hole after temporary plugging, MPa; Δp perfs1 represents the initial perforation hole friction, MPa; P2 represents the second pressure value when the fracturing curve is stable after temporary plugging, MPa; P1 represents the first pressure value when the fracturing curve is stable before temporary plugging, MPa.

[0065] In one embodiment of the present invention, with respect to the above S5, the number of perforations not plugged after temporary plugging is determined according to the following formula based on the friction resistance of the perforations after temporary plugging, the operation displacement, the density of the fracturing fluid and the diameter of the perforations:

[0066]

[0067] Where, N2 represents the number of perforations that are not plugged after temporary plugging, and Q represents the construction displacement, m 3 / min; Δp perfs2 represents the friction resistance of the perforation hole after temporary plugging, MPa; ρ represents the density of the fracturing fluid, kg / m 3 ; D is the diameter of the perforation hole, m; C d It indicates the flow coefficient set according to the perforation hole diameter and fracturing fluid viscosity.

[0068] In one embodiment of the present invention, with respect to the above S6, the temporary plugging efficiency is determined according to the following formula based on the number of perforations that are not plugged after temporary plugging, the number of perforations in the wellbore, and the number of temporary plugging balls:

[0069]

[0070] Wherein, η represents the temporary plugging efficiency, %; N represents the number of temporary plugging balls, pieces; N1 represents the number of perforations in the wellbore, pieces; N2 represents the number of perforations that are not plugged after temporary plugging, pieces.

[0071] In one embodiment of the present invention, reference Figure 2 After all the sand-adding stages are completed, that is, after the last section of sand-adding fracturing is completed, 0.3-0.5 times the volume of the wellbore is pumped with medium-viscosity fracturing fluid (30-60 mPa·s), and then 1-1.5 times the volume of the wellbore is injected with low-viscosity fracturing fluid (1-30 mPa·s) to displace all the sand in the wellbore into the reservoir; then the pump is stopped by stepping down the construction displacement, and the construction displacement is reduced to zero within 1-2 minutes to complete the fracturing construction of this section.

[0072] In order to explain the above-mentioned method for analyzing the temporary plugging efficiency of multi-cluster fracturing in horizontal wells more clearly, a specific embodiment is used for illustration below.

[0073] Take a deep shale gas well as an example, Figure 3 Schematic diagram of the analysis process of temporary plugging efficiency of multi-cluster fracturing in horizontal wells, and the temporary plugging efficiency of multi-cluster fracturing in the deep shale gas well is analyzed.

[0074] The fracturing design parameters of the deep shale gas well A section are: wellbore volume 60m 3 , perforation clusters 9 clusters, hole diameter 11mm, perforation holes 54 holes, designed acid volume 10m 3 , designed high viscosity fracturing fluid volume 100m 3 , designed sand volume 240t, designed displacement 18m 3 / min, the construction control pressure is 120MPa, and the number of temporary plugging balls with a single diameter of 15mm is designed to be 18. Only one temporary plugging process is implemented.

[0075] S31, determine the initial perforation hole friction process:

[0076] 9 clusters of 89mm perforating guns, 99mm bridge plug tools and 103mm soluble bridge plugs were pumped into the well using cable pumps. The maximum outer diameter of the perforating gun barrel string was 103mm, so that the bridge plug was set at the designed setting position to isolate the previous fracturing stage. The perforating gun was used to perforate 54 holes according to the designed perforating parameters. The hole diameter was 11mm. After the perforating barrel string was pulled out of the wellhead, fracturing construction was carried out.

[0077] Use 65mm bridge plug ball and 2m 3 / min construction flow rate, 5m 3 Low viscosity fracturing fluid and 10m 3After all the acid is injected into the wellbore, increase the construction displacement to 5m 3 / min, accelerate the bridge plug ball to reach the bridge plug position, and the cumulative liquid volume to be injected into the wellbore is equal to 42m 3 When the construction displacement is reduced to 2m 3 / min, so that the bridge plug ball can be stably seated on the bridge plug when it reaches the bridge plug position later to isolate the previous fracturing stage;

[0078] The total amount of liquid to be injected into the wellbore is equal to 66m 3 When adding 100mPa·s high viscosity fracturing fluid 100m 3 At the same time, the construction displacement is increased to 18m 3 / min; after the high-viscosity fracturing fluid is pumped, switch to 3mPa·s low-viscosity fracturing fluid, adopt a two-stage continuous sand adding mode, and stop adding sand when the cumulative sand volume reaches 140t; switch the fracturing fluid from low viscosity to medium viscosity, and use 68m 3 The medium-viscosity fracturing fluid displaces all the sand in the wellbore into the reservoir, and the pressure value P1=86MPa when the fracturing curve is stable before temporary plugging is recorded. The initial perforation hole friction resistance is calculated using the following formula:

[0079]

[0080] Among them, Δp perfs1 represents the initial perforation friction, MPa; ρ represents the density of the fracturing fluid, equal to 1000kg / m 3 ; Q represents the construction displacement, which is equal to 18m 3 / min; N1 is the number of perforations in the wellbore, which is equal to 54; D is the diameter of the perforation, which is equal to 0.011m; C d It represents the flow coefficient set according to the perforation hole diameter and fracturing fluid viscosity, which is equal to 0.9.

[0081] Calculate Δp perfs1 =2.19MPa.

[0082] S32, determine the friction process of the perforation holes after temporary plugging:

[0083] 18 temporary plugging balls with a diameter of 15 mm were placed in the wellbore, and the temporary plugging balls were pumped using a medium-viscosity fracturing fluid of 40 mPa·s. 3 / minConstruction displacement injection 30m 3 When the construction displacement is reduced to 1m 3 / min, cumulative injection 67m 3 After the temporary plugging ball is stably sealed in the blasthole, the construction displacement is increased to 18m in a step-by-step manner within 2 minutes. 3 / min, record the pressure value P2=88.01MPa when the fracturing curve is stable after temporary plugging, and use the following formula to calculate the friction resistance of the perforation hole after temporary plugging:

[0084] Δp perfs2 =Δp perfs1 +(P2-P1)

[0085] Among them, Δp perfs2 Indicates the friction resistance of the perforation hole after temporary plugging, MPa; Δp perfs1 represents the initial perforation hole friction, which is equal to 2.19MPa; P2 represents the second pressure value when the fracturing curve is stable after temporary plugging, which is equal to 88.01MPa; P1 represents the first pressure value when the fracturing curve is stable before temporary plugging, which is equal to 86MPa.

[0086] Calculate Δp perfs2 =4.20MPa.

[0087] S33, process of determining the number of perforation holes that are not plugged after temporary plugging:

[0088] The number of perforations that are not plugged after temporary plugging is determined by the following formula:

[0089]

[0090] Where N2 represents the number of perforations that are not plugged after temporary plugging, Q represents the construction displacement, which is equal to 18m 3 / min; Δp perfs2 represents the friction resistance of the perforation hole after temporary plugging, which is equal to 4.20MPa; ρ represents the density of the fracturing fluid, which is equal to 1000kg / m 3 ; D represents the diameter of the perforation hole, which is equal to 0.011m; C d It represents the flow coefficient set according to the perforation hole diameter and fracturing fluid viscosity, which is equal to 0.9.

[0091] Calculation shows that N2=39.

[0092] S34, process of determining temporary blocking efficiency:

[0093] The temporary plugging efficiency is determined by the following formula:

[0094]

[0095] Wherein, η represents the temporary plugging efficiency, %; N represents the number of temporary plugging balls, which is equal to 18; N1 represents the number of perforations in the wellbore, which is equal to 54; N2 represents the number of perforations that are not plugged after temporary plugging, which is equal to 39.

[0096] Calculated η = 83.33%.

[0097] After recording the pressure value P2 when the fracturing curve stabilizes after temporary plugging, switch the medium-viscosity fracturing fluid to low-viscosity fracturing fluid to carry out the second stage of sand-adding fracturing. Since the temporary plugging process will no longer be implemented in the future, only low-viscosity fracturing fluid will be used for sand-adding fracturing. Stop adding sand when the designed sand volume is reached, and pump 30m 3 Medium viscosity fracturing fluid (40mPa·s), then inject 65m 3 Low-viscosity fracturing fluid (3mPa·s) is used to displace all the sand in the wellbore into the reservoir. The pump is then stopped by stepping down the construction displacement, and the construction displacement is reduced to zero within 1-2 minutes to complete the fracturing construction of this section.

[0098] It should be noted that, although the operations of the method of the present invention are described in a specific order in the above embodiments and the accompanying drawings, this does not require or imply that the operations must be performed in the specific order, or that all the operations shown must be performed to achieve the desired results. Additionally or alternatively, some steps may be omitted, multiple steps may be combined into one step, and / or one step may be decomposed into multiple steps.

[0099] The implementation of the horizontal well multi-cluster fracturing temporary plugging efficiency analysis device can refer to the implementation of the above method, and the repeated parts will not be repeated. The term "module" or "unit" used below can be a combination of software and / or hardware that implements a predetermined function. Although the device described in the following embodiments is preferably implemented in software, the implementation of hardware, or a combination of software and hardware, is also possible and conceivable.

[0100] Based on the same inventive concept, the present invention also proposes a device for analyzing the temporary plugging efficiency of multi-cluster fracturing in horizontal wells. Figure 4 As shown, the device comprises:

[0101] The trigger module 110 is used to sequentially trigger the following modules to execute in a loop when a temporary plugging process is required in the first stage of sand fracturing and in each subsequent stage of sand fracturing until the last stage of sand fracturing is completed;

[0102] The data recording module 120 before temporary plugging is used to determine the first pressure value when the fracturing curve is stable before temporary plugging;

[0103] The initial hole friction calculation module 130 is used to determine the initial hole friction according to the number of holes in the wellbore, the hole diameter, the density of the fracturing fluid and the operation displacement;

[0104] The post-temporary plugging data recording module 140 is used to determine the second pressure value when the fracturing curve is stable after temporary plugging;

[0105] A perforation friction calculation module 150 after temporary plugging, for determining the perforation friction after temporary plugging according to the initial perforation friction, the first pressure value and the second pressure value;

[0106] The unplugged hole number calculation module 160 is used to determine the number of unplugged perforations after temporary plugging according to the friction resistance of the perforations after temporary plugging, the operation displacement, the density of the fracturing fluid and the diameter of the perforations;

[0107] The temporary plugging efficiency calculation module 170 is used to determine the temporary plugging efficiency according to the number of perforations that are not plugged after temporary plugging, the number of perforations in the wellbore and the number of temporary plugging balls.

[0108] In one embodiment of the present invention, the initial hole friction calculation module is specifically used for:

[0109] The initial perforation hole friction resistance is determined by the following formula:

[0110]

[0111] Among them, Δp perfs1 represents the initial perforation friction, MPa; ρ represents the fracturing fluid density, kg / m 3 ; Q represents the construction displacement, m 3 / min; N1 is the number of perforation holes, pieces; D is the diameter of the perforation holes, m; C d It indicates the flow coefficient set according to the perforation hole diameter and fracturing fluid viscosity.

[0112] In one embodiment of the present invention, the hole friction calculation module after temporary plugging is specifically used for:

[0113] The friction resistance of the perforation hole after temporary plugging is determined by the following formula:

[0114] Δp perfs2 =Δp perfs1 +(P2-P1);

[0115] Among them, Δp perfs2 Indicates the friction resistance of the perforation hole after temporary plugging, MPa; Δp perfs1 represents the initial perforation hole friction, MPa; P2 represents the second pressure value when the fracturing curve is stable after temporary plugging, MPa; P1 represents the first pressure value when the fracturing curve is stable before temporary plugging, MPa.

[0116] In one embodiment of the present invention, the module for calculating the number of unblocked holes is specifically used for:

[0117] The number of perforations that are not plugged after temporary plugging is determined by the following formula:

[0118]

[0119] Where, N2 represents the number of perforations that are not plugged after temporary plugging, and Q represents the construction displacement, m 3 / min; Δpperfs2 represents the friction resistance of the perforation hole after temporary plugging, MPa; ρ represents the density of the fracturing fluid, kg / m 3 ; D is the diameter of the perforation hole, m; C d It indicates the flow coefficient set according to the perforation hole diameter and fracturing fluid viscosity.

[0120] In one embodiment of the present invention, the temporary blocking efficiency calculation module is specifically used for:

[0121] The temporary plugging efficiency is determined by the following formula:

[0122]

[0123] Wherein, η represents the temporary plugging efficiency, %; N represents the number of temporary plugging balls, pieces; N1 represents the number of perforations in the wellbore, pieces; N2 represents the number of perforations that are not plugged after temporary plugging, pieces.

[0124] It should be noted that although several modules of the horizontal well multi-cluster fracturing temporary plugging efficiency analysis device are mentioned in the above detailed description, this division is only exemplary and not mandatory. In fact, according to an embodiment of the present invention, the features and functions of two or more modules described above can be embodied in one module. Conversely, the features and functions of one module described above can be further divided into multiple modules for embodiment.

[0125] Based on the above invention concept, Figure 5 As shown, the present invention also proposes a computer device 500, including a memory 510, a processor 520, and a computer program 530 stored in the memory 510 and executable on the processor 520, wherein the processor 520 implements the aforementioned horizontal well multi-cluster fracturing temporary plugging efficiency analysis method when executing the computer program 530.

[0126] Based on the aforementioned inventive concept, the present invention proposes a computer-readable storage medium, wherein the computer-readable storage medium stores a computer program, and when the computer program is executed by a processor, the aforementioned method for analyzing the temporary plugging efficiency of multi-cluster fracturing in horizontal wells is implemented.

[0127] Based on the aforementioned inventive concept, the present invention proposes a computer program product, which includes a computer program. When the computer program is executed by a processor, a method for analyzing the temporary plugging efficiency of multi-cluster fracturing in horizontal wells is implemented.

[0128] The method and device for analyzing the temporary plugging efficiency of multi-cluster fracturing in horizontal wells proposed in the embodiments of the present invention can solve the problem that the current actual fracturing construction cannot quantitatively characterize the temporary plugging efficiency of multi-cluster fracturing in horizontal wells. By obtaining actual fracturing construction data, the initial perforation hole friction resistance and the hole friction resistance after temporary plugging are determined, and the number of perforations that are not plugged after temporary plugging is calculated, the temporary plugging efficiency of fracturing is quantitatively characterized, and quantitative analysis of the temporary plugging efficiency of multi-cluster fracturing in horizontal wells is achieved. The degree of opening of multiple clusters of hydraulic fracturing clusters in the horizontal well section is determined, which is of great significance for improving the accuracy of fracturing schemes, guiding the precise optimization and real-time adjustment of temporary plugging parameters, and reducing temporary plugging costs.

[0129] It will be appreciated by those skilled in the art that embodiments of the present invention may be provided as methods, devices, or computer program products. Therefore, the present invention may take the form of a complete hardware embodiment, a complete software embodiment, or an embodiment combining software and hardware. Moreover, the present invention may take the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0130] The present invention is described with reference to flowcharts and / or block diagrams of methods and computer program products according to embodiments of the present invention. It should be understood that each process and / or block in the flowchart and / or block diagram, as well as the combination of processes and / or blocks in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to generate a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the processes in the flowchart and / or block diagram. Figure 1 A process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0131] These computer program instructions may also be stored in a computer-readable memory capable of directing a computer or other programmable data processing device to operate in a specific manner, so that the instructions stored in the computer-readable memory produce an article of manufacture comprising an instruction device, which implements the process Figure 1 A process or multiple processes and / or boxes Figure 1 A function specified in one or more boxes.

[0132] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operating steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing instructions for implementing the process. Figure 1 A process or multiple processes and / or boxes Figure 1The steps for the functions specified in one or more boxes.

[0133] Finally, it should be noted that the above-described embodiments are only specific implementations of the present invention, which are used to illustrate the technical solutions of the present invention, rather than to limit them. The protection scope of the present invention is not limited thereto. Although the present invention is described in detail with reference to the above-described embodiments, ordinary technicians in the field should understand that any technician familiar with the technical field can still modify the technical solutions recorded in the above-described embodiments within the technical scope disclosed by the present invention, or can easily think of changes, or make equivalent replacements for some of the technical features therein; and these modifications, changes or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present invention, and should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention shall be subject to the protection scope of the claims.

Claims

1. A method for analyzing temporary plugging efficiency of multi-cluster fracturing in horizontal wells, characterized in that: include: When temporary plugging is required in the first stage of sand fracturing and in each subsequent stage of sand fracturing, the following steps are performed cyclically until the last stage of sand fracturing is completed: Determine the first pressure value when the fracturing curve is stable before temporary plugging; Determine the initial perforation friction according to the number of perforations in the wellbore, the perforation diameter, the density of the fracturing fluid and the operation displacement; Determine the second pressure value when the fracturing curve is stable after temporary plugging; Determine the perforation hole friction resistance after temporary plugging according to the initial perforation hole friction resistance, the first pressure value when the fracturing curve is stable before temporary plugging, and the second pressure value when the fracturing curve is stable after temporary plugging; Determine the number of perforations that remain unplugged after temporary plugging based on the friction resistance of the perforations after temporary plugging, the operation displacement, the density of the fracturing fluid and the diameter of the perforations; The temporary plugging efficiency is determined based on the number of perforations that are not plugged after temporary plugging, the number of perforations in the wellbore, and the number of temporary plugging balls; The initial perforation hole friction resistance is determined by the following formula: Among them, Δp perfs1 represents the initial perforation friction, MPa; ρ represents the fracturing fluid density, kg / m 3 ; Q represents the construction displacement, m 3 / min; N1 is the number of perforation holes in the wellbore, pieces; D is the diameter of the perforation hole, m; C d It represents the flow coefficient set according to the perforation hole diameter and fracturing fluid viscosity; The friction resistance of the perforation hole after temporary plugging is determined according to the following formula: Δp perfs2 =Δp perfs1 +(P2-P1); Among them, Δp perfs2 Indicates the friction resistance of the perforation hole after temporary plugging, MPa; Δp perfs1 represents the initial perforation hole friction, MPa; P2 represents the second pressure value when the fracturing curve is stable after temporary plugging, MPa; P1 represents the first pressure value when the fracturing curve is stable before temporary plugging, MPa; The number of perforations that are not plugged after temporary plugging is determined according to the following formula: Where, N2 represents the number of perforations that are not plugged after temporary plugging, and Q represents the construction displacement, m 3 / min; Δp perfs2 represents the friction resistance of the perforation hole after temporary plugging, MPa; ρ represents the density of the fracturing fluid, kg / m 3 ; D is the diameter of the perforation hole, m; C d It indicates the flow coefficient set according to the perforation hole diameter and fracturing fluid viscosity.

2. The method according to claim 1, characterized in that The temporary plugging efficiency is determined by the following formula: Wherein, η represents the temporary plugging efficiency, %; N represents the number of temporary plugging balls, pieces; N1 represents the number of perforations in the wellbore, pieces; N2 represents the number of perforations that are not plugged after temporary plugging, pieces.

3. A device for analyzing the temporary plugging efficiency of multi-cluster fracturing in horizontal wells, characterized in that: include: A trigger module is used to sequentially trigger the following modules to execute in a loop when a temporary plugging process is required for sand fracturing in the first stage and in each subsequent stage until the sand fracturing in the last stage is completed; A data recording module before temporary plugging, used to determine the first pressure value when the fracturing curve is stable before temporary plugging; The initial hole friction calculation module is used to determine the initial hole friction according to the number of holes in the wellbore, the hole diameter, the density of the fracturing fluid and the operation displacement; A data recording module after temporary plugging, used to determine a second pressure value when the fracturing curve is stable after temporary plugging; A perforation friction calculation module after temporary plugging, used to determine the perforation friction after temporary plugging according to the initial perforation friction, the first pressure value when the fracturing curve is stable before temporary plugging, and the second pressure value when the fracturing curve is stable after temporary plugging; The module for calculating the number of unplugged holes is used to determine the number of unplugged holes after temporary plugging according to the friction resistance of the perforated holes after temporary plugging, the operation displacement, the density of the fracturing fluid and the diameter of the perforated holes; A temporary plugging efficiency calculation module is used to determine the temporary plugging efficiency according to the number of perforations that are not plugged after temporary plugging, the number of perforations in the wellbore and the number of temporary plugging balls; Among them, the initial hole friction calculation module is specifically used for: The initial perforation hole friction resistance is determined by the following formula: Among them, Δp perfs1 represents the initial perforation friction, MPa; ρ represents the fracturing fluid density, kg / m 3 ; Q represents the construction displacement, m 3 / min; N1 is the number of perforation holes in the wellbore, pieces; D is the diameter of the perforation hole, m; C d It represents the flow coefficient set according to the perforation hole diameter and fracturing fluid viscosity; Among them, the hole friction calculation module after temporary plugging is specifically used for: The friction resistance of the perforation hole after temporary plugging is determined by the following formula: Δp perfs2 =Δp perfs1 +(P2-P1); Among them, Δp perfs2 Indicates the friction resistance of the perforation hole after temporary plugging, MPa; Δp perfs1 represents the initial perforation hole friction, MPa; P2 represents the second pressure value when the fracturing curve is stable after temporary plugging, MPa; P1 represents the first pressure value when the fracturing curve is stable before temporary plugging, MPa; Among them, the unblocked hole quantity calculation module is specifically used for: The number of perforations that are not plugged after temporary plugging is determined by the following formula: Where, N2 represents the number of perforations that are not plugged after temporary plugging, and Q represents the construction displacement, m 3 / min; Δp perfs2 represents the friction resistance of the perforation hole after temporary plugging, MPa; ρ represents the density of the fracturing fluid, kg / m 3 ; D is the diameter of the perforation hole, m; C d It indicates the flow coefficient set according to the perforation hole diameter and fracturing fluid viscosity.

4. The device according to claim 3, characterized in that The temporary blocking efficiency calculation module is specifically used for: The temporary plugging efficiency is determined by the following formula: Wherein, η represents the temporary plugging efficiency, %; N represents the number of temporary plugging balls, pieces; N1 represents the number of perforations in the wellbore, pieces; N2 represents the number of perforations that are not plugged after temporary plugging, pieces.

5. 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, the method according to any one of claims 1 to 2 is implemented.

6. A computer-readable storage medium, characterized in that: The computer-readable storage medium stores a computer program, and when the computer program is executed by a processor, the method according to any one of claims 1 to 2 is implemented.

7. A computer program product, characterized in that The computer program product comprises a computer program, and when the computer program is executed by a processor, the method according to any one of claims 1 to 2 is implemented.

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