Quantitative evaluation method for fracture temporary plugging effect

Abstract

The invention relates to the field of hydraulic fracturing of oil and gas field development, and particularly discloses a quantitative evaluation method for a fracturing temporary plugging effect, which comprises the following steps of: obtaining a fracture length change condition before and after temporary plugging of each cluster hole of a fracturing section based on a cluster fracture length real-time result which is obtained by fracturing monitoring and shows a fracturing fluid sweep condition, and further calculating to obtain a cluster fracture length extension change rate of the cluster holes; the quantitative evaluation index based on the cluster seam length extension change rate is constructed for quantitative evaluation of the temporary plugging effect, quantitative evaluation of the temporary plugging effect is achieved, and scientific and reasonable suggestion optimization is conducted on a subsequent temporary plugging scheme.

Description

Technical Field

[0001] The present invention relates to the field of hydraulic fracturing in oil and gas field development, and particularly to a quantitative evaluation method for the temporary plugging effect of fracturing. Background Art

[0002] The multi-cluster fracturing technology in the horizontal well section is a necessary technology for the efficient development of unconventional oil and gas resources. Due to the influence of reservoir heterogeneity, mechanical differences between clusters, and stress interference between fractures, it is difficult for multiple fractures within the section to initiate simultaneously and expand evenly. The in-section temporary plugging technology helps to achieve balanced transformation within the section by plugging the perforations or fracture openings to increase the net wellbore pressure and force the fluid flow to turn. However, during the in-section temporary plugging fracturing process, it is difficult to ensure that the injected temporary plugging agent can effectively plug the eroded perforations due to the erosion of the proppant on the perforations. In addition, the reservoir heterogeneity results in complex fracture opening and morphology at the fracture openings, and the uncertainty of the temporary plugging effect at the fracture openings is relatively large. Therefore, evaluating the temporary plugging effect is crucial for real-time adjustment of the temporary plugging plan and subsequent optimization of the temporary plugging plan design.

[0003] Currently, the methods for judging the temporary plugging effect include technologies such as microseismic and fiber optic outside the pipe. However, microseismic mainly identifies the fracture rupture points, and there are certain difficulties in judging the liquid flow direction and the effect before and after temporary plugging of each cluster. The fiber optic outside the pipe can monitor the liquid injection and sand injection volume of each perforation cluster in real time, but the use cost is high, and it is difficult to be widely promoted on site. In summary, there is currently no effective quantitative evaluation method for the temporary plugging effect of multi-cluster fracturing in the horizontal well section. Summary of the Invention

[0004] In the summary of the invention section, some selected concepts are introduced in a simplified form, which will be further elaborated in the following detailed implementation section. This summary of the invention section is not intended to identify any key features or essential features of the claimed subject matter, nor is it intended to be used to help determine the scope of the claimed subject matter.

[0005] The object of the present invention is to provide a quantitative evaluation method for the temporary plugging effect based on the fracturing monitoring result data, to provide real-time temporary plugging guidance by monitoring the fracturing fluid coverage range in real time, and to optimize and adjust the subsequent temporary plugging plan for the quantitative evaluation of the temporary plugging effect.

[0006] According to one aspect of the present disclosure, a quantitative evaluation method for the temporary plugging effect of fracturing is provided, including the following steps: S1, obtaining the fracturing monitoring result, which includes the fracture length data of the temporarily plugged section clusters and the fracture length data of the non-temporarily plugged section clusters; S2, calculating the reduction value of the fracture length extension rate of the non-temporarily plugged section clusters, and the initial increase value or initial reduction value of the fracture length extension rate of each cluster after temporary plugging in the temporarily plugged section; S3. Subtract the decrease value of the fracture length extension rate of the clusters in the unblocked section from the initial increase value or decrease value of the fracture length extension rate of each cluster after temporary plugging in the temporary plugging section, to obtain the corrected increase value or corrected decrease value of the fracture length extension rate of each cluster after temporary plugging in the temporary plugging section; S4. Count the number of cluster holes in the disadvantaged clusters among the first N1 of the corrected increase values of the fracture length extension rate of each cluster after temporary plugging in the temporary plugging section, where the corrected increase value of the fracture length extension rate is greater than the first specified value, and denote it as N2; and count the number of cluster holes in the advantaged clusters among the first N3 of the corrected decrease values of the fracture length extension rate of each cluster after temporary plugging in the temporary plugging section, where the corrected decrease value of the fracture length extension rate is greater than the second specified value, and denote it as N4; S5. Evaluate the temporary plugging effect according to the temporary plugging effect evaluation index D, where D = (N2 + N4) / (N1 + N3).

[0007] As a preferred implementation manner, step S2 of calculating the decrease value of the fracture length extension rate of the clusters in the unblocked section includes: calculating the decrease value of the extension rate of a single unblocked section; calculating the average decrease value of the extension rate of all unblocked sections, and using the average decrease value as the decrease value of the fracture length extension rate of the clusters in the unblocked section.

[0008] As a preferred implementation manner, calculating the decrease value of the extension rate of a single unblocked section includes: calculating the average value of the fracture length data per unit time of the first time window according to the first cluster fracture length data set of the unblocked section in the first time window after the fracturing displacement is stabilized; calculating the average value of the fracture length data per unit time of the second time window according to the second cluster fracture length data set of the unblocked section in the second time window after the first time window when the fracturing displacement is stabilized; subtracting the average value of the fracture length data per unit time of the first time window from the average value of the fracture length data per unit time of the second time window to obtain the decrease value of the extension rate of a single unblocked section.

[0009] As a preferred implementation manner, the initial increase value or initial decrease value of the fracture length extension rate of each cluster after temporary plugging in step S2 includes: calculating the average value of the fracture length data per unit time of the third time window according to the third cluster fracture length data set of the temporary plugging section in the third time window after the fracturing displacement is stabilized; calculating the average value of the fracture length data per unit time of the fourth time window according to the fourth cluster fracture length data set of the temporary plugging section in the fourth time window after the third time window when the fracturing displacement is stabilized; subtracting the average value of the fracture length data per unit time of the third time window from the average value of the fracture length data per unit time of the fourth time window to obtain the initial increase value or initial decrease value of the extension rate of a single temporary plugging section.

[0010] According to another aspect of the present disclosure, there is provided a computer-readable storage medium, on which instructions are stored, and when the instructions are executed by at least one processor, the at least one processor is caused to execute the method described in the present disclosure.

[0011] According to another aspect of the present disclosure, there is provided a computer program product including instructions that, when executed by at least one processor, cause the at least one processor to execute the methods described in the present disclosure.

[0012] Compared with the prior art, the advantages of the present invention are as follows: based on the real-time results of the cluster fracture length presenting the propagation of fracturing fluid during fracture monitoring, the changes in the fracture length before and after temporary plugging of each cluster of holes in the fracture section are obtained, and then the expansion change rate of the cluster fracture length of the cluster of holes is calculated. A quantitative evaluation index based on the expansion change rate of the cluster fracture length is constructed to quantitatively evaluate the temporary plugging effect, providing scientific and reasonable suggestions for optimizing the subsequent temporary plugging scheme. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 is a flowchart of a method for quantitatively evaluating the temporary plugging effect of fracturing according to an example of the present disclosure; Figure 2 is a graph of real-time monitoring results of the temporarily plugged section and the non-temporarily plugged section according to an example of the present disclosure; Figure 3 is a statistical graph of the cluster fracture lengths of the temporarily plugged section and the non-temporarily plugged section according to an example of the present disclosure; Figure 4 is a statistical graph of the fracture propagation reduction rate of the non-temporarily plugged section according to an example of the present disclosure; Figure 5 is a statistical graph of the fracture propagation increase or reduction rate of the temporarily plugged section according to an example of the present disclosure; Figure 6 is a statistical calculation graph of the temporary plugging judgment index of this section according to an example of the present disclosure. DETAILED DESCRIPTION

[0014] The present invention will be further described below with reference to the accompanying drawings. In the following part of the specification, for the purpose of explanation, a large number of specific details are set forth to provide a more thorough understanding of the present disclosure. However, these specific details are merely exemplary and not restrictive, and it will be obvious to those skilled in the art that the present disclosure can be implemented without these specific details.

[0015] References throughout the specification to "one implementation", "implementations", "exemplary implementations", "some implementations", "various implementations", etc. indicate that the described implementations of the present disclosure may include specific features, structures, or characteristics, however, not every implementation necessarily includes these specific features, structures, or characteristics. In addition, some implementations may have some, all, or none of the features described for other implementations.

[0016] In a manner that is most conducive to understanding the claimed subject matter, various operations may be described as a number of discrete actions or processes in sequence. However, the described order should not be construed as implying that these operations are necessarily dependent on that order. On the contrary, these operations may not be performed in the order presented. In some other implementations, various additional operations may also be performed, and / or various described operations may be ignored.

[0017] In the specification and claims, the technical terms "first", "second", etc. only distinguish one entity or operation from another entity or operation, and should not be construed as indicating or implying relative importance or implicitly specifying the quantity, specific order, or primary-secondary relationship of the indicated technical features. In the description of the embodiments of the present application, the meaning of "a plurality" is two or more, unless otherwise specifically defined.

[0018] In the specification and claims, the phrase "A and / or B" may be used to represent one of the following: (A), (B), (A and B). Similarly, the phrase "A, B, and / or C" may be used to represent one of the following: (A), (B), (C), (A and B), (A and C), (B and C), (A and B and C).

[0019] This example evaluates the temporary plugging effect based on the uniformity of the entire sweep pattern of the fracturing operation. A good temporary plugging effect can be considered as plugging the dominant cluster. Then, the liquid intake of the pores in this cluster decreases, and the growth rate of the fracture length will decrease. However, the amount of liquid injected during fracturing is constant. Then, the remaining fracturing fluid will flow towards the inferior cluster, accelerating its liquid intake, making the sweep pattern more uniform. The temporary plugging effect is quantitatively evaluated by comprehensively considering the changes in the growth rates of the cluster fracture lengths of the dominant cluster and the inferior cluster.

[0020] As an example, a method for quantitatively evaluating the temporary plugging effect of fracturing includes the following steps: S1. Obtain the fracturing monitoring results, which include the cluster fracture length data of the temporarily plugged section and the cluster fracture length data of the non-temporarily plugged section; S2. Calculate the reduction value of the growth rate of the cluster fracture length of the non-temporarily plugged section, and the initial increase value or initial reduction value of the growth rate of the fracture length of each cluster after temporary plugging of the temporarily plugged section; S3. Subtract the reduction value of the growth rate of the cluster fracture length of the non-temporarily plugged section from the initial increase value or reduction value of the growth rate of the fracture length of each cluster after temporary plugging of the temporarily plugged section to obtain the corrected increase value or corrected reduction value of the growth rate of the fracture length of each cluster after temporary plugging of the temporarily plugged section; S4. Statistically count the number of cluster holes, denoted as N2, whose corrected increased value of the fracture length expansion rate of the inferior clusters among the first N1 clusters with the corrected increased value of the fracture length expansion rate of each cluster after temporary plugging in the temporarily plugged section is greater than the first specified value; and statistically count the number of cluster holes, denoted as N4, whose corrected decreased value of the fracture length expansion rate of the superior clusters among the first N3 clusters with the corrected decreased value of the fracture length expansion rate of each cluster after temporary plugging in the temporarily plugged section is greater than the second specified value. S5. Evaluate the temporary plugging effect according to the temporary plugging effect evaluation index D, where D = (N2 + N4) / (N1 + N3).

[0021] In step S1, the fracture monitoring results are obtained by the wide - area electromagnetic method. The wide - area electromagnetic method for fracture monitoring is a technique that supplies alternating electromagnetic waves through the wellbore, and the underground conductor generates an antenna effect. Measuring points are deployed on the surface to measure the electric field signals caused by the antenna effect and infer the swept range of the fracturing fluid. In this example, the real - time monitoring data is the plane monitoring results refreshed every 10 minutes, and its content includes at least the fracturing fluid swept length of each cluster (i.e., cluster fracture length data), and may also include information such as the swept area, swept length, and swept width of all the fracturing fluid. Therefore, other real - time fracturing monitoring methods that can obtain cluster fracture length data can also be used, such as micro - seismic monitoring.

[0022] The temporarily plugged section is the fracturing section where temporary plugging measures have been taken by putting in temporary plugging balls or temporary plugging agents. The non - temporarily plugged section is the fracturing section where no temporary plugging measures have been taken. The cluster fracture length data is the fracturing fluid swept length corresponding to the perforation clusters of the fracturing section.

[0023] In step S2, calculating the decreased value of the cluster fracture length expansion rate of the non - temporarily plugged section includes: calculating the decreased value of the expansion rate of a single non - temporarily plugged section; calculating the average decreased value of the expansion rate of all non - temporarily plugged sections, and taking the average decreased value as the decreased value of the cluster fracture length expansion rate of the non - temporarily plugged section.

[0024] Among them, calculating the decreased value of the expansion rate of a single non - temporarily plugged section includes: calculating the average value of the cluster fracture length data per unit time of the first time window according to the first cluster fracture length data set of the non - temporarily plugged section in the first time window after the fracturing displacement is stable; calculating the average value of the cluster fracture length data per unit time of the second time window according to the second cluster fracture length data set of the non - temporarily plugged section in the second time window after the first time window when the fracturing displacement is stable; subtracting the average value of the cluster fracture length data per unit time of the first time window from the average value of the cluster fracture length data per unit time of the second time window to obtain the decreased value of the expansion rate of a single non - temporarily plugged section.

[0025] Specifically, the reduction value of the cluster fracture length extension rate in the un-temporarily plugged section means that during the extension process of the fracturing fluid, the rate gradually decreases with the increase of time. To eliminate factors such as displacement, in this example, the entire fracturing time period is divided into three equal stages, and the cluster fracture length data of the time window sampled every ten minutes with stable displacement in the second and third stages are selected to calculate the average fracture length per minute (unit time). Then, the average fracture length per minute in the third stage is subtracted from that in the second stage to obtain the reduction value of the single-stage cluster fracture length extension rate. Then, all un-temporarily plugged sections are comprehensively considered to calculate the average extension rate reduction value. V w : In the formula: l m is the length affected by the cluster fractures every 10 minutes in the third stage, s n is the length affected by the cluster fractures every 10 minutes in the second stage, m is the number of times the monitoring data in the third stage is updated (updated every 10 minutes), n is the number of times the monitoring data in the second stage is updated (updated every 10 minutes), Vp is the average extension rate reduction value of all un-temporarily plugged sections, and p is the number of all un-temporarily plugged sections.

[0026] The initial increase value or initial decrease value of the fracture length extension rate of each cluster after temporary plugging in the temporarily plugged section described in step S2 includes: calculating the average fracture length data per unit time of the third cluster fracture length data set of the temporarily plugged section in the third time window after the fracturing displacement is stable; calculating the average fracture length data per unit time of the fourth cluster fracture length data set of the temporarily plugged section in the fourth time window after the third time window when the fracturing displacement is stable; subtracting the average fracture length data per unit time of the third time window from the average fracture length data per unit time of the fourth time window to obtain the initial increase value or initial decrease value of the extension rate of the single-stage temporarily plugged section.

[0027] Specifically, when calculating the increase or decrease rate of the fracture length extension of each cluster after temporary plugging in the temporarily plugged section, the time boundary between the second and third stages when the temporary plugging agent is injected is still used to calculate the average fracture length per minute, and the average fracture length per minute in the third stage is subtracted from that in the second stage to obtain the increase value or decrease value V of the fracture length extension rate of the single-stage cluster after temporary plugging. z :

[0028] In the formula: u m is the length affected by the cluster fractures every 10 minutes in the third stage, w n is the length affected by the cluster fractures every 10 minutes in the second stage, x is the number of times the monitoring data in the third stage is updated (updated every 10 minutes), and y is the number of times the monitoring data in the second stage is updated (updated every 10 minutes).

[0029] In the first time window, the second time window, the third time window, and the fourth time window, the same 10-minute sampling interval is used to obtain cluster fracture length data to form a cluster fracture length data set, so as to suppress the influence of sampling interval differences as much as possible and improve the monitoring accuracy of the fracture length expansion rate of the temporary plugging section.

[0030] In step S3, the initial increase value or decrease value of the fracture length expansion rate of each cluster after temporary plugging of the temporary plugging section is subtracted from the decrease value of the cluster fracture length expansion rate of the non-temporary plugging section to obtain the corrected increase value or corrected decrease value V of the fracture length expansion rate of each cluster after temporary plugging of the temporary plugging section, in order to eliminate the decrease in the expansion rate of the fracture itself without temporary plugging. The formula is:

[0031] In the formula: V is the increase value or decrease value of the fracture length expansion rate of the temporary plugging section clusters after eliminating the influence of the decrease in the expansion rate of the fracture itself, Vp is the average decrease value of the expansion rate of all non-temporary plugging sections, V z is the increase value or decrease value of the fracture length expansion rate of the temporary plugging section clusters.

[0032] The disadvantaged clusters of the temporary plugging section in step S4 refer to those with a relatively weak opening degree and a relatively short corresponding fracture length before temporary plugging, and the advantaged clusters refer to those with a relatively strong opening degree and a relatively long corresponding fracture length before temporary plugging. Select the first N1 = 5 clusters with an increasing expansion rate of the disadvantaged clusters of the temporary plugging section and the first N3 = 5 clusters with a decreasing expansion rate of the advantaged clusters before temporary plugging, and count the number N2 of the first 5 rates (V) of the advantaged clusters of the temporary plugging section with a decrease greater than 0.1 m / min (the first specified value), and the number N4 of the cluster holes of the first 5 rates (V) of the disadvantaged clusters of the temporary plugging section with an increase greater than 0.1 m / min (the second specified value).

[0033] As a preferred implementation, the first specified value is the median of the increase values of the fracture length expansion rates of all fracturing sections of the whole well; and the second specified value is the median of the decrease values of the fracture length expansion rates of all fracturing sections of the whole well.

[0034] Then proceed to step S5, calculate (N2 + N4) / (N1 + N3) and display it in the form of a percentage, that is, obtain the temporary plugging effect evaluation index D, and determine the temporary plugging effect according to the numerical value of the evaluation index D in combination with the empirical interval.

[0035] As a preferred embodiment, N1 = N3, and the value of (N1 + N3) / the total number of cluster holes in a single-stage temporary plugging section ∈ [0.4 - 0.6]. Taking the perforated section of a typical hydraulic fracturing operation as an example, generally there are eight or nine clusters in one stage, arranged on the east and west sides respectively, so there are generally 18 clusters. Then, the top five in terms of statistical advantage and the top five in terms of statistical disadvantage are counted. These 10 clusters are equivalent to the ones with the longest and shortest propagation among all clusters. The purpose of temporary plugging is to make the propagation of these clusters uniform and make their fracture lengths not much different from those of other clusters, so as to achieve an excellent temporary plugging effect.

[0036] Taking the data of a specific shale gas well as an example below, this well has a total of 32 stages, 26 temporary plugging stages, and 6 non-temporary plugging stages.

[0037] See Figure 1 , a quantitative evaluation method for the temporary plugging effect based on wide-area electromagnetic method fracturing monitoring data, including the following steps; (1) Conduct wide-area electromagnetic method fracturing monitoring to obtain real-time monitoring results; (2) Separate and organize the cluster fracture length data of the temporary plugging section and the non-temporary plugging section; (3) Calculate the reduction amount of the cluster fracture length extension rate in the non-temporary plugging section, and calculate the increase or decrease rate of the fracture length of each cluster after temporary plugging in the temporary plugging section; (4) Subtract the reduction amount of the cluster fracture length extension rate in the non-temporary plugging section to obtain the increase or decrease amount of the extension rate of the cluster fracture length due to the temporary plugging effect; (5) Statistically count the top five clusters with increased extension rate in the disadvantaged clusters and the top five clusters with decreased extension rate in the advantaged clusters in the temporary plugging section, and add them together to obtain the temporary plugging effect evaluation parameter; (6) According to the above evaluation parameter, divide the temporary plugging effect evaluation criteria; (7) Evaluate the temporary plugging effect.

[0038] As Figure 2 shown, the color of the picture can be changed according to the time of placing the temporary plugging ball, and the change in the propagation pattern before and after temporary plugging can be compared to qualitatively judge the temporary plugging effect first.

[0039] In step (2), the temporary plugging section is the fracturing section where temporary plugging measures have been taken by placing temporary plugging balls or temporary plugging agents, and the non-temporary plugging section is the fracturing section where no temporary plugging measures have been taken. The cluster fracture length data is the length of the fracturing fluid propagation corresponding to the perforation clusters in the fracturing section. According to the monitoring data after fracturing, the data of the temporary plugging section and the non-temporary plugging section are separately counted. Subtract the cluster fracture length data in the first 10 minutes from the cluster fracture length data in the last 10 minutes, and so on, to obtain the growth rate of the cluster hole gap length every 10 minutes. See Figure 3 , where the left side is the monitored cluster fracture length data, and the right side is the increase value of the cluster length within every ten minutes obtained by subtracting the first 10 minutes from the last 10 minutes.

[0040] In step (3), the reduction rate of the cluster fracture length extension in the unblocked section refers to that during the extension process of the fracturing fluid, the rate gradually decreases with the increase of time. To eliminate factors such as displacement, the entire fracturing time period is divided into three equal stages. The data of the cluster fracture length for ten minutes with stable displacement in the second and third stages is selected to calculate the average fracture length per minute, and the average fracture length per minute in the third stage is subtracted from that in the second stage to obtain the reduction rate of the single-section cluster fracture length. Here, we select a section of data for display. The calculated reduction rate of the fracture extension speed of the first section is 0.23 m / min, as shown in Figure 4 In this example, there are 6 unblocked sections in total. The reduction rates of the fracture extension speeds of all sections are calculated to obtain the statistical table of the reduction rates of the fracture extension speeds in the unblocked sections of this well, and the average reduction rate of the fracture extension speed is 0.13 m / min, as shown in Table 1.

[0041] Table 1 Statistical table of the reduction rate of the fracture extension speed in the unblocked section

[0042] In step (3), when calculating the increase or decrease rate of the fracture length extension of each cluster after plugging in the plugged section, specifically, taking the time boundary of the second and third stages when the plugging agent is injected to calculate the average fracture length per minute, and subtracting the average fracture length per minute in the second stage from that in the third stage. Taking the third plugged section of the example well as an example, the increase or decrease amount of the fracture length extension rate of each cluster is obtained.

[0043] In step (4), subtracting the average reduction rate of the fracture extension speed of 0.13 m / min from the increase or decrease amount of the fracture length extension rate of each cluster in step (3) to obtain the increase or decrease amount of the fracture with the extension rate only affected by the plugging effect, as shown in Figure 5 shown.

[0044] In step (5), the disadvantaged clusters in the plugged section refer to those with a relatively weak opening degree and a relatively short corresponding fracture length before plugging, and the advantaged clusters refer to those with a relatively strong opening degree and a relatively long corresponding fracture length before plugging. Here, taking the third section as an example, the top five clusters with an increasing extension rate of the disadvantaged clusters in the plugged section and the top five clusters with a decreasing extension rate of the advantaged clusters are selected. The number of cluster holes with the reduction of the top 5 rates (V) of the plugged advantaged clusters greater than 0.1 m / min and the increase of the top 5 rates (V) of the plugged disadvantaged clusters greater than 0.1 m / min are counted, and the number is divided by 10 and presented in the form of a percentage. The evaluation parameter of the plugging effect of this section is 80, as shown in Figure 6 shown.

[0045] According to the steps in step (5), the evaluation parameters of the plugging effects of the remaining plugged sections are calculated in turn, and then the evaluation criteria for the plugging effect are determined according to the magnitudes of the evaluation index data of all plugged sections.

[0046] In step (6), according to the calculation results in step (5), the evaluation criteria for the plugging effect are formulated: ①No obvious effect: 0% < D < 60%; ②Average effect: 60% ≤ D < 80%; ③Good effect: 80% ≤ D ≤ 100%.

[0047] Substitute the temporary plugging effect of each section into the temporary plugging evaluation criteria to obtain the quantitative evaluation of the temporary plugging effect of each section.

[0048] Table 2 Temporary Plugging Efficiency Statistical Table

[0049] Some implementations described herein may include articles. An article may include a storage medium. Examples of storage media may include volatile and non-volatile, removable and non-removable media implemented by any method or technology for storing information (e.g., computer-readable instructions, data structures, program modules, or other data). Storage media may include, but are not limited to: random access memory (RAM), read-only memory (ROM), programmable read-only memory (PROM), erasable programmable read-only memory (EPROM), electrically erasable programmable read-only memory (EEPROM), flash memory or other semiconductor memory, optical discs (CDs), digital versatile discs (DVDs) or other optical storage, magnetic tape cartridges, tapes, magnetic disk storage or other magnetic storage devices, or any other medium capable of storing information. In some implementations, an article may store executable computer program instructions that, when executed by one or more processing units, cause the processing units to perform the operations described herein. Executable computer program instructions may include any suitable type of code, e.g., source code, compiled code, interpreted code, executable code, static code, dynamic code, etc. Executable computer program instructions may be implemented using any appropriate high-level, low-level, object-oriented, visual, compiled, and / or interpreted programming language.

[0050] Some exemplary implementations of the present disclosure are described below.

[0051] Example 2 describes a computer-readable storage medium having instructions stored thereon that, when executed by at least one processor, cause the at least one processor to perform the method according to any one of the preceding examples.

[0052] Example 3 describes a computer program product that includes instructions that, when executed by at least one processor, cause the at least one processor to perform the method according to any one of the preceding examples.

[0053] The above are only the preferred embodiments of the present invention, and are not intended to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention shall be included within the protection scope of the present invention.

Claims

1. A quantitative evaluation method for temporary plugging effect of fracturing, characterized in that: The following steps are involved: S1, obtaining fracturing monitoring results, which include temporary plugging section cluster fracture length data and non-temporary plugging section cluster fracture length data; S2, calculating the reduction value of the crack length expansion rate of the cluster in the unblocked section, and the initial increase value or initial decrease value of the crack length expansion rate of each cluster after the temporary blocking of the temporary blocking section; S3, subtracting the reduction value of the seam length expansion rate of the cluster in the un-temporarily blocked section from the initial increase value or reduction value of the seam length expansion rate of each cluster after the temporary blocking section, to obtain a corrected increase value or a corrected reduction value of the seam length expansion rate of each cluster after the temporary blocking section; S4, counting the number of cluster holes whose fracture length expansion rate correction increase value is greater than the first specified value in the inferior cluster N1 before the fracture length expansion rate correction increase value of each cluster after temporary plugging, recorded as N2; and counting the number of cluster holes whose fracture length expansion rate correction reduction value is greater than the second specified value in the dominant cluster N3 before the fracture length expansion rate correction reduction value of each cluster after temporary plugging, recorded as N4; S5. Evaluate the temporary blocking effect according to the temporary blocking effect evaluation index D, D=(N2+N4) / (N1+N3).

2. The method according to claim 1, characterized in that: The fracturing monitoring result obtained in step S1 comes from wide-area electromagnetic fracturing monitoring or microseismic fracturing monitoring.

3. The method according to claim 1, characterized in that: Step S2 of calculating the reduction value of the expansion rate of the cluster seam length of the non-temporarily blocked section includes: Calculate the expansion rate reduction value of a single section without temporary blockage; The average expansion rate reduction value of all non-temporarily blocked sections is calculated, and the average expansion rate reduction value is used as the expansion rate reduction value of the cluster fracture length of the non-temporarily blocked section.

4. The method according to claim 3, characterized in that: Calculation of the expansion rate reduction value of a single section without temporary blockage includes: Calculate the average value of the cluster fracture length data per unit time in the first time window according to the first cluster fracture length data set of the un-temporarily plugged section in the first time window after the fracturing displacement is stabilized; Calculate the average value of the unit time cluster fracture length data of the second time window according to the second cluster fracture length data set of the un-temporarily plugged section in the second time window after the first time window after the fracturing displacement is stabilized; The expansion rate reduction value of the single non-temporarily blocked section is obtained by subtracting the average value of the cluster crack length data per unit time in the first time window from the average value of the cluster crack length data per unit time in the second time window.

5. The method according to claim 4, characterized in that: The initial increase value or initial decrease value of the crack length expansion rate of each cluster after the temporary blocking of the temporary blocking section in step S2 includes: Calculate the average value of the cluster fracture length data per unit time in the third time window according to the third cluster fracture length data set of the temporary plugging section in the third time window after the fracturing displacement is stabilized; Calculate the average value of the unit time cluster fracture length data of the fourth time window according to the fourth cluster fracture length data set of the temporary plugging section in the fourth time window after the third time window after the fracturing displacement is stabilized; The initial increase value or initial decrease value of the expansion rate of the single temporary blocking section is obtained by subtracting the average value of the cluster crack length data per unit time of the third time window from the average value of the cluster crack length data per unit time of the fourth time window.

6. The method according to claim 5, characterized in that: The cluster seam length data is acquired using the same sampling interval in the first time window, the second time window, the third time window and the fourth time window to form a cluster seam length data set.

7. The method according to claim 1, characterized in that: N1=N3, and the value of (N1+N3) / total number of cluster holes in a single temporary plugging section∈[0.4~0.6].

8. The method according to claim 1, characterized in that: The first designated value is the median of the increase in the fracture length expansion rate of all the fracturing sections of the entire well; the second designated value is the median of the decrease in the fracture length expansion rate of all the fracturing sections of the entire well.

9. A computer-readable storage medium having instructions stored thereon, wherein when the instructions are executed by at least one processor, the at least one processor executes the method according to any one of claims 1 to 8.

10. A computer program product comprising instructions, which when executed by at least one processor causes the at least one processor to perform the method according to any one of claims 1-8.

Images