CN112304770B - Method and system for quantitatively analyzing complexity of fracture after fracturing - Google Patents
Method and system for quantitatively analyzing complexity of fracture after fracturing Download PDFInfo
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- 238000000034 method Methods 0.000 title claims abstract description 30
- 238000010276 construction Methods 0.000 claims abstract description 12
- 238000004364 calculation method Methods 0.000 claims description 5
- 238000004445 quantitative analysis Methods 0.000 claims description 5
- 238000003860 storage Methods 0.000 claims description 4
- 230000009466 transformation Effects 0.000 abstract description 7
- 230000000694 effects Effects 0.000 abstract description 5
- 238000005457 optimization Methods 0.000 abstract description 5
- 238000013461 design Methods 0.000 abstract description 4
- 206010017076 Fracture Diseases 0.000 description 32
- 208000010392 Bone Fractures Diseases 0.000 description 31
- 239000007789 gas Substances 0.000 description 9
- 238000011156 evaluation Methods 0.000 description 8
- 238000003825 pressing Methods 0.000 description 7
- 238000011158 quantitative evaluation Methods 0.000 description 5
- 238000004458 analytical method Methods 0.000 description 4
- 230000009286 beneficial effect Effects 0.000 description 3
- 238000012512 characterization method Methods 0.000 description 3
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- VNWKTOKETHGBQD-UHFFFAOYSA-N methane Chemical compound C VNWKTOKETHGBQD-UHFFFAOYSA-N 0.000 description 2
- 238000005086 pumping Methods 0.000 description 2
- BVKZGUZCCUSVTD-UHFFFAOYSA-L Carbonate Chemical compound [O-]C([O-])=O BVKZGUZCCUSVTD-UHFFFAOYSA-L 0.000 description 1
- 230000006835 compression Effects 0.000 description 1
- 238000007906 compression Methods 0.000 description 1
- 238000013211 curve analysis Methods 0.000 description 1
- 238000006073 displacement reaction Methods 0.000 description 1
- 238000009826 distribution Methods 0.000 description 1
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- 230000004048 modification Effects 0.000 description 1
- 239000003345 natural gas Substances 0.000 description 1
- 239000002245 particle Substances 0.000 description 1
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- 239000011435 rock Substances 0.000 description 1
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N3/00—Investigating strength properties of solid materials by application of mechanical stress
- G01N3/08—Investigating strength properties of solid materials by application of mechanical stress by applying steady tensile or compressive forces
- G01N3/10—Investigating strength properties of solid materials by application of mechanical stress by applying steady tensile or compressive forces generated by pneumatic or hydraulic pressure
- G01N3/12—Pressure testing
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N2203/00—Investigating strength properties of solid materials by application of mechanical stress
- G01N2203/003—Generation of the force
- G01N2203/0042—Pneumatic or hydraulic means
- G01N2203/0044—Pneumatic means
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N2203/00—Investigating strength properties of solid materials by application of mechanical stress
- G01N2203/0058—Kind of property studied
- G01N2203/006—Crack, flaws, fracture or rupture
Abstract
The invention provides a method and a system for quantitatively analyzing the complexity of a fracture after fracturing, and belongs to the field of shale gas fracturing. The method quantitatively evaluates the complexity of the crack after fracturing through the wave crest number of a GdP/dG curve, the maximum slope of a first part of the GdP/dG curve and the standard deviation of a second part; the first part is a curve part from the original point to the first crest and then to the first trough in the GdP/dG curve; the second portion refers to the portion of the GdP/dG curve that includes from the first trough to the terminus. The invention can quantitatively analyze the complexity of the fractured cracks, can clearly know the transformation degree of each stage of fracturing, and is helpful for guiding the fracture design optimization, the fracture construction optimization and improving the transformation effect.
Description
Technical Field
The invention belongs to the field of shale gas fracturing, and particularly relates to a method and a system for quantitatively analyzing the complexity of a fracture after fracturing.
Background
At present, the hydraulic fracture post-fracturing fracture diagnosis and analysis technology is widely applied to various oil and gas reservoirs such as shale, tight sandstone, carbonate rock and the like. The post-pressing crack diagnosis technology is mainly used for estimating the crack scale, complexity, crack extension condition and the like. Shale gas well fracturing belongs to volume fracturing, and the core of the volume fracturing is to greatly improve the complexity of cracks so as to increase the transformation volume and improve the post-fracturing yield, so that analysis of the complexity of the cracks is important for evaluating the fracturing effect of the shale gas well.
In the past post-pressing analysis, the fluctuation degree of a fracturing construction pressure curve and the fluctuation degree of a G function curve are generally used for qualitatively analyzing the complexity of the crack (the fluctuation degree of the G function is closely related to the complexity of the post-pressing crack), and the method is helpful for judging the complexity of the post-pressing crack to a certain degree, but is easy to cause misjudgment, because the apparent fluctuation degree of the curve has certain deception, the fluctuation degree difference shown in different data ranges is larger; this also results in failure to form a more fixed fracture complexity evaluation system. Therefore, it is necessary to provide a quantitative analysis method for the complexity of the fracture after pressing to solve the above problems.
The Chinese patent publication CN106769463A discloses a quantitative characterization method of the complexity of the core fracture after pressing, which is mainly used for quantitatively evaluating the complexity of the fracture according to the inclination angle and the area of the core fracture after pressing, and belongs to a laboratory evaluation method of the core scale; the Chinese literature (a quantitative characterization of shale volume fracturing complex cracks) (in 2017 01 of oil and natural gas geology) discloses a quantitative characterization method of shale volume fracturing complex cracks, which quantitatively characterizes shale post-fracturing complex cracks through 4 established typical crack distribution forms and fracturing physical simulation experiments; the Chinese literature (G function curve analysis-based fracture complexity evaluation research) (the (science, technology and engineering) period 2016 (02) discloses fracture complexity evaluation after compression, which analyzes the fracture fluid loss behavior of a natural fracture when the natural fracture is opened on the basis of classical G function theory, corrects the loss coefficient of a natural fracture closing stage by introducing a free variable omega and establishes a pressure drop model considering the natural fracture opening; the curve shapes of the simple main fracture, the first derivative dp/dG communicating one natural fracture with multiple natural fractures, the superimposed derivatives ISIP-Gdp/dG and Gdp/dG were compared and analyzed. The method is characterized in that the G function theory is corrected, the influence of the filter loss characteristics under the opening of the natural cracks on the G function is more considered, the complexity of the cracks is judged according to the corrected G function curve, but when the complexity of the cracks is judged, whether the natural cracks are communicated or not is judged by simply using the fluctuation of the G function on vision (namely qualitative rather than quantitative), more complex cracks are formed or only a crack system mainly comprising main cracks is formed, and a method and thought for quantitatively evaluating the fluctuation of the G function are not provided, and specific indexes are not formed.
Disclosure of Invention
The invention aims to solve the problems in the prior art, and provides a method and a system for quantitatively analyzing the complexity of a crack after fracturing, so that the complexity of the crack after fracturing is systematically known, the design and construction optimization of the fracturing are guided, and the efficient yield increase of a shale gas well is realized.
The invention is realized by the following technical scheme:
the method for quantitatively analyzing the complexity of the crack after fracturing quantitatively evaluates the complexity of the crack after fracturing through the peak number of a GdP/dG curve, the maximum slope of a first part of the GdP/dG curve and the standard deviation of a second part of the GdP/dG curve;
the first part is a curve part from the original point to the first crest and then to the first trough in the GdP/dG curve;
the second portion refers to the portion of the GdP/dG curve that includes from the first trough to the terminus.
The method comprises the following steps:
(1) Collecting fracturing construction second point data, and making a GdP/dG graph according to the fracturing construction second point data;
(2) Adjusting GdP/dG graph to make its abscissa range be between [0,0.1 ];
(3) Obtaining the number of peaks on GdP/dG curve；
(4) Calculating the maximum slope of the first part and the standard deviation of the second part of the GdP/dG curve;
(5) And obtaining the crack complexity according to the wave crest number, the maximum slope of the first part and the standard deviation of the second part.
The operation of calculating the maximum slope of the first portion in step (4) includes:
reading the ordinate H corresponding to the highest point of the first part (i.e. the highest point of the first peak) from the data of the GdP/dG curve max Abscissa T max ；
The maximum slope k of the first portion is calculated using the following equation:
the operation of calculating the standard deviation of the second part in the step (4) includes:
(a) Calculating an average value of the ordinate of the second portion
Wherein; x is x i Is the ordinate of each data point in the second portion, i=1, 2 3.n; n is the number of data points of the second portion;
(b) Calculating the variance of the second portion:
(c) Calculating the standard deviation of the second part:
the operation of step (5) comprises:
a1, if three first-class complex judgment conditions are simultaneously met, judging that the first-class complex judgment conditions are first-class complex;
a2, judging that the vehicle is four-class complex if any one of three judging conditions of the four-class complex is met;
a3, if three judging conditions of second-class complexity are met at the same time, judging that the second-class complexity is achieved; if one or two of the three first-class complex judgment conditions are met and the other two second-class complex judgment conditions are met, judging that the two second-class complex judgment conditions are met;
a4, if three complex judging conditions are met at the same time, judging that the three complex judging conditions are three complex; if one or two of the three first-class complex judgment conditions are met and the other three first-class complex judgment conditions are met, judging that the first-class complex judgment conditions are three first-class complex; if one of three first-class complex judgment conditions is met, one of three second-class complex judgment conditions is met, and one of three third-class complex judgment conditions is met, judging as three third-class complex; if one or two of the second-class complex judgment conditions are met and the other of the second-class complex judgment conditions are met, the second-class complex judgment conditions are judged to be third-class complex;
the first three complex judgment conditions are as follows: the number of wave peaks is more than 12, the maximum slope of the first part is more than 100000, and the standard deviation of the second part is more than 40;
the three complex judgment conditions are: the number of peaks is more than 9 and less than or equal to 12, the maximum slope of the first part is more than 60000 and less than or equal to 100000, and the standard deviation of the second part is more than 25 and less than or equal to 40;
three complex judgment conditions are as follows: the number of peaks is more than 5 and less than or equal to 9, the maximum slope of the first part is more than 12000 and less than or equal to 60000, and the standard deviation of the second part is more than or equal to 15 and less than or equal to 25;
four complex three judgment conditions are: the number of peaks is less than or equal to 5, the maximum slope of the first part is less than or equal to 12000, and the standard deviation of the second part is less than 15.
The invention also provides a system for quantitatively analyzing the complexity of the fractured cracks, which comprises:
the curve drawing unit is used for drawing a GdP/dG curve according to the fracturing construction second point data;
an abscissa adjusting unit connected with the graph drawing unit for adjusting the range of the abscissa of the GdP/dG graph output by the graph drawing unit to be between [0,0.1 ];
the wave crest count unit is connected with the abscissa adjustment unit and used for obtaining the wave crest number on the GdP/dG curve;
the maximum slope calculation unit is connected with the abscissa adjustment unit and is used for obtaining the maximum slope of the first part;
the standard deviation calculation unit is connected with the abscissa adjustment unit and is used for obtaining the standard deviation of the second part;
the crack complexity judging unit is respectively connected with the wave crest number counting unit, the maximum slope calculating unit and the standard deviation calculating unit and is used for judging the crack complexity according to the wave crest number, the maximum slope of the first part and the standard deviation of the second part.
The maximum slope calculating unit reads the ordinate H corresponding to the highest point of the first part from the data of the GdP/dG curve output by the abscissa adjusting unit max Abscissa T max The maximum slope k of the first portion is then calculated using the following equation:
the standard deviation calculating unit reads the ordinate of each data point of the second part from the data of the GdP/dG curve output by the abscissa adjusting unit, and then calculates the standard deviation of the second part by using the following formula:
wherein; sigma is the standard deviation, S is the variance,is the average value of the ordinate of the second part, x i Is the ordinate of each data point in the second portion, i=1, 2 3.n; n is the number of data points of the second portion.
The crack complexity judging unit is used for:
if three first-class complex judging conditions are met at the same time, judging that the first-class complex is obtained;
if any one of three judgment conditions of four-class complexity is satisfied, judging that the four-class complexity is achieved;
if the two-level complex three judging conditions are met at the same time, judging that the two-level complex is achieved; if one or two of the three first-class complex judgment conditions are met and the other two second-class complex judgment conditions are met, judging that the two second-class complex judgment conditions are met;
if three complex judging conditions are met at the same time, judging that the three complex judging conditions are three complex; if one or two of the three first-class complex judgment conditions are met and the other three first-class complex judgment conditions are met, judging that the first-class complex judgment conditions are three first-class complex; if one of three first-class complex judgment conditions is met, one of three second-class complex judgment conditions is met, and one of three third-class complex judgment conditions is met, judging as three third-class complex; if one or two of the second-class complex judgment conditions are satisfied, the other of the second-class complex judgment conditions are satisfied, the judgment is made as third-class complex.
The present invention also provides a computer readable storage medium storing at least one program executable by a computer, which when executed by the computer, causes the computer to perform the steps in the method of quantitatively analyzing post-fracture complexity of the present invention.
Compared with the prior art, the invention has the beneficial effects that: the invention can quantitatively analyze the complexity of the fractured cracks, can clearly know the transformation degree of each stage of fracturing, and is helpful for guiding the fracture design optimization, the fracture construction optimization and improving the transformation effect.
Drawings
FIG. 1 is a block diagram of the steps of the method of the present invention;
FIG. 2 is a graph of G-function for an embodiment of the present invention;
fig. 3 is a schematic diagram of the system of the present invention.
Detailed Description
The invention is described in further detail below with reference to the attached drawing figures:
1) Determining GdP/dG function curve fluctuation times
Intuitively, the fluctuation degree of the GdP/dG curve (a G function curve) is closely related to the number of wave crests (wave troughs) and the data oscillation amplitude in the GdP/dG curve (as shown in fig. 2), the wave crests and the wave troughs and the data oscillation amplitude are intuitively and closely related to the coordinate axis range, and the data oscillation amplitude can be judged through quantitative analysis of data. In order to judge the fluctuation times (namely, the wave crest number) of the GdP/dG curve under the same scale, the invention limits the range of the abscissa Nolte G time corresponding to the GdP/dG curve between [0,0.1] (as shown in figure 2), and then determines the fluctuation times (namely, the wave crest number) in a counting mode.
2) GdP/dG function curve fluctuation degree evaluation
The GdP/dG function curve is divided into two parts, the first part is the curve part (i.e. the first peak is included) included from the origin point to the first peak and then to the first trough in the curve, and the remaining part (i.e. the curve part included from the first trough back to the end point) is the second part (also referred to as the first peak back part in the invention). The first part is in the short time after stopping the pump, the data change speed often reflects connectivity among cracks and extensibility of the cracks after stopping the pump, the faster the data change, the better the connectivity and extensibility of the cracks are indicated, and the slope corresponding to the maximum value of the first peak is used as a judgment standard for quantitative evaluation.
The fluctuation degree of the second part of curve often reflects crack connectivity and opening and closing quantity, and the higher the fluctuation degree is, the higher the crack complexity is. The invention evaluates the fluctuation degree by using the standard deviation of curve data, and the larger the standard deviation is, the stronger the fluctuation is.
3) Shale gas post-pressure fracture complexity quantitative evaluation index
Based on the first point and the second point, the invention establishes quantitative evaluation indexes of the complexity of the crack, as shown in the table 1:
TABLE 1
In table 1, as long as one of the three conditions of the number of peaks, the maximum slope of the first portion, and the standard deviation of the second portion satisfies the current level, the current level is determined even if the other conditions satisfy the previous level, that is, as long as any one of the three conditions does not satisfy the current level, the next level is determined, and since the first-order complexity is the highest level, the three conditions of the first-order complexity must be satisfied at the same time, and since the fourth-order complexity is the lowest level, the three conditions of the fourth-order complexity are determined as long as any one of the three conditions of the fourth-order complexity is satisfied, that is, the fourth-order complexity. The method comprises the following steps:
the first three complex judgment conditions are: the number of wave peaks is more than 12, the maximum slope of the first part is more than 100000, and the standard deviation of the second part is more than 40;
the three complex judgment conditions are: the number of peaks is more than 9 and less than or equal to 12, the maximum slope of the first part is more than 60000 and less than or equal to 100000, and the standard deviation of the second part is more than 25 and less than or equal to 40;
three complex judgment conditions are as follows: the number of peaks is more than 5 and less than or equal to 9, the maximum slope of the first part is more than 12000 and less than or equal to 60000, and the standard deviation of the second part is more than or equal to 15 and less than or equal to 25;
four complex three judgment conditions are: the number of wave peaks is less than or equal to 5, the maximum slope of the first part is less than or equal to 12000, and the standard deviation of the second part is less than 15;
the judging steps are as follows:
a1, if three first-class complex judgment conditions are simultaneously met, judging that the first-class complex judgment conditions are first-class complex;
a2, judging that the vehicle is four-class complex if any one of three judging conditions of the four-class complex is met;
a3, if three judging conditions of second-class complexity are met at the same time, judging that the second-class complexity is achieved; if one or two of the three first-class complex judgment conditions are met and the other two second-class complex judgment conditions are met, judging that the two second-class complex judgment conditions are met;
a4, if three complex judging conditions are met at the same time, judging that the three complex judging conditions are three complex; if one or two of the three first-class complex judgment conditions are met and the other three first-class complex judgment conditions are met, judging that the first-class complex judgment conditions are three first-class complex; if one of three first-class complex judgment conditions is met, one of three second-class complex judgment conditions is met, and one of three third-class complex judgment conditions is met, judging as three third-class complex; if one or two of the second-class complex judgment conditions are satisfied, the other of the second-class complex judgment conditions are satisfied, the judgment is made as third-class complex.
Embodiments of the invention are as follows:
the method is applied to the post-pressure evaluation of a shale gas well in the Chuan nan area, and as shown in figure 1, the method comprises the following steps:
1. sorting fracturing construction second point data (the data comprise wellhead pressure, pumping displacement, pumping time, proppant concentration and particle size, which are generally exported by an instrument vehicle during fracturing operation), and making a GdP/dG graph by using Meyer fracturing design software (or other software and modes), as shown in fig. 2;
2. the GdP/dG curve was adjusted to have an abscissa range of [0,0.1 ]: the curve is placed over the interval [0,0.1], the left-most value (minimum) of the abscissa of the curve is placed at 0 point, and the right-most value (maximum) of the abscissa is placed at 0.1 position. (essentially, the curve is compressed or expanded laterally).
3. The number of peaks on the GdP/dG curve is obtained, for example, the number of peaks can be directly counted, or the number of peaks on the curve can be obtained by adopting the existing method.
4. Deriving GdP/dG curve data, and calculating the maximum slope of the first part and the standard deviation of the second part:
reading the ordinate H corresponding to the highest point of the first part (i.e. the highest point of the first peak) from the data of the GdP/dG curve max Abscissa T max The maximum slope k of the first portion is calculated using the following equation:
the standard deviation of the second part is calculated using the formula:
wherein; sigma is the standard deviation, S is the variance,is the average value of the ordinate of the second part, x i Is the ordinate of each data point in the second portion, i=1, 2 3.n; n is the number of data points of the second portion.
5. The fracture complexity of the fracture section was evaluated according to the fracture complexity quantitative evaluation index shown in table 1, and the results are shown in table 2:
| number of fracturing segments | Number of peaks | Maximum slope of first portion | Standard deviation of the second part | Crack complexity level |
| 1 | 3 | 8704.78 | 7.82 | Four and so on complex |
| 2 | 2 | 2013.43 | 7.16 | Four and so on complex |
| 5 | 1 | 1900.48 | 20.58 | Four and so on complex |
| 7 | 13 | 63215.31 | 33.29 | Second-class complexity |
| 8 | 13 | 13303.98 | 16.14 | Three-etc. complex |
| 9 | 3 | 5817.79 | 16.55 | Four and so on complex |
| 10 | 13 | 31417.16 | 29.86 | Three-etc. complex |
| 11 | 12 | 44010.54 | 31.54 | Three-etc. complex |
| 12 | 3 | 5919.22 | 28.64 | Four and so on complex |
| 13 | 4 | 9699.33 | 28.64 | Four and so on complex |
| 15 | 4 | 15714.29 | 12.38 | Four and so on complex |
TABLE 2
In the experiment, 15 fracturing sections are all counted, and each fracturing section is evaluated independently, namely 15 GdP/dG curves are made, and then the fracture complexity of the 15 fracturing sections is evaluated respectively.
As shown in fig. 3, the present invention further provides a system for quantitatively analyzing the complexity of a fracture after fracturing, comprising:
a graph drawing unit 100 for drawing a GdP/dG graph according to the fracturing construction seconds;
an abscissa adjusting unit 200 connected to the graph drawing unit 100, for adjusting the range of the abscissa of the GdP/dG graph outputted by the graph drawing unit to be between [0,0.1 ];
the wave crest counting unit 300 is connected with the abscissa adjusting unit 200 and is used for obtaining the wave crest number on the GdP/dG curve;
a maximum slope calculation unit 400, connected to the abscissa adjustment unit 200, for obtaining a maximum slope of the first portion;
a standard deviation calculating unit 500, connected to the abscissa adjusting unit 200, for obtaining a standard deviation of the second portion;
the crack complexity judging unit 600 is connected to the peak count counting unit 300, the maximum slope calculating unit 400, and the standard deviation calculating unit 500, respectively, and is configured to judge the crack complexity according to the peak count, the maximum slope of the first portion, and the standard deviation of the second portion.
The maximum slope calculating unit 400 reads the ordinate H corresponding to the highest point of the first part from the data of the GdP/dG curve outputted from the abscissa adjusting unit 200 max Abscissa T max The maximum slope k of the first portion is then calculated using the following equation:
the standard deviation calculating unit 500 reads the ordinate of each data point of the second part from the data of the GdP/dG curve outputted from the abscissa adjusting unit 200, and then calculates the standard deviation of the second part by using the following formula:
wherein; sigma is the standard deviation, S is the variance,is the average value of the ordinate of the second part, x i Is the ordinate of each data point in the second portion, i=1, 2 3.n; n is the number of data points of the second portion.
The crack complexity determination unit 600 is configured to:
if three first-class complex judging conditions are met at the same time, judging that the first-class complex is obtained;
if any one of three judgment conditions of four-class complexity is satisfied, judging that the four-class complexity is achieved;
if the two-level complex three judging conditions are met at the same time, judging that the two-level complex is achieved; if one or two of the three first-class complex judgment conditions are met and the other two second-class complex judgment conditions are met, judging that the two second-class complex judgment conditions are met;
if three complex judging conditions are met at the same time, judging that the three complex judging conditions are three complex; if one or two of the three first-class complex judgment conditions are met and the other three first-class complex judgment conditions are met, judging that the first-class complex judgment conditions are three first-class complex; if one of three first-class complex judgment conditions is met, one of three second-class complex judgment conditions is met, and one of three third-class complex judgment conditions is met, judging as three third-class complex; if one or two of the second-class complex judgment conditions are satisfied, the other of the second-class complex judgment conditions are satisfied, the judgment is made as third-class complex.
The present invention also provides a computer readable storage medium storing at least one program executable by a computer, which when executed by the computer, causes the computer to perform the steps in the method of quantitatively analyzing post-fracture complexity of the present invention.
The invention analyzes the limitation of the prior shale gas pressure post-fracture complexity evaluation, and provides a quantitative analysis method for fracture complexity. The method is based on a G function analysis curve, and three factors which can best reflect the complexity degree of the crack in the G function curve are researched and optimized: the number of wave peaks, the maximum slope of the first wave peak and the standard deviation of data after the first wave peak are calculated and analyzed to form a quantitative evaluation system for the complexity of the crack. The method belongs to a method for diagnosing and quantitatively analyzing the fracture after hydraulic fracturing. The invention is mainly applied to the field of shale gas pressure post-evaluation, can clearly conduct quantitative analysis on the complexity of the crack after fracturing, is beneficial to understanding the crack making effect of fracturing transformation, and is beneficial to guiding fracturing design and improving transformation effect.
The foregoing technical solution is only one embodiment of the present invention, and various modifications and variations can be easily made by those skilled in the art based on the application methods and principles disclosed in the present invention, not limited to the methods described in the foregoing specific embodiments of the present invention, so that the foregoing description is only preferred and not in a limiting sense.
Claims (6)
1. A method for quantitatively analyzing the complexity of a fracture after fracturing, which is characterized by comprising the following steps of: the method quantitatively evaluates the complexity of the crack after fracturing through the wave crest number of a GdP/dG curve, the maximum slope of a first part of the GdP/dG curve and the standard deviation of a second part;
the first part is a curve part from the original point to the first crest and then to the first trough in the GdP/dG curve;
the second portion refers to the portion of the GdP/dG curve that includes from the first trough to the terminus;
the method comprises the following steps:
(1) Collecting fracturing construction second point data, and making a GdP/dG graph according to the fracturing construction second point data;
(2) Adjusting GdP/dG graph to make its abscissa range be between [0,0.1 ];
(3) Obtaining the peak number on a GdP/dG curve;
(4) Calculating the maximum slope of the first part and the standard deviation of the second part of the GdP/dG curve;
(5) Obtaining crack complexity according to the number of peaks, the maximum slope of the first part and the standard deviation of the second part;
the operation of calculating the maximum slope of the first portion in step (4) includes:
reading the ordinate H corresponding to the highest point of the first part from the data of the GdP/dG curve max Abscissa T max ；
The maximum slope k of the first portion is calculated using the following equation:
the operation of calculating the standard deviation of the second part in the step (4) includes:
(a) Calculating an average value of the ordinate of the second portion
Wherein; x is x i Is the ordinate of each data point in the second portion, i=1, 2 3.n; n is the number of data points of the second portion;
(b) Calculating the variance of the second portion:
(c) Calculating the standard deviation of the second part:
the operation of step (5) comprises:
a1, if three first-class complex judgment conditions are simultaneously met, judging that the first-class complex judgment conditions are first-class complex;
a2, judging that the vehicle is four-class complex if any one of three judging conditions of the four-class complex is met;
a3, if three judging conditions of second-class complexity are met at the same time, judging that the second-class complexity is achieved; if one or two of the three first-class complex judgment conditions are met and the other two second-class complex judgment conditions are met, judging that the two second-class complex judgment conditions are met;
a4, if three complex judging conditions are met at the same time, judging that the three complex judging conditions are three complex; if one or two of the three first-class complex judgment conditions are met and the other three first-class complex judgment conditions are met, judging that the first-class complex judgment conditions are three first-class complex; if one of three first-class complex judgment conditions is met, one of three second-class complex judgment conditions is met, and one of three third-class complex judgment conditions is met, judging as three third-class complex; if one or two of the second-class complex judgment conditions are met and the other of the second-class complex judgment conditions are met, the second-class complex judgment conditions are judged to be third-class complex;
the first three complex judgment conditions are as follows: the number of wave peaks is more than 12, the maximum slope of the first part is more than 100000, and the standard deviation of the second part is more than 40;
the three complex judgment conditions are: the number of peaks is more than 9 and less than or equal to 12, the maximum slope of the first part is more than 60000 and less than or equal to 100000, and the standard deviation of the second part is more than 25 and less than or equal to 40;
three complex judgment conditions are as follows: the number of peaks is more than 5 and less than or equal to 9, the maximum slope of the first part is more than 12000 and less than or equal to 60000, and the standard deviation of the second part is more than or equal to 15 and less than or equal to 25;
four complex three judgment conditions are: the number of peaks is less than or equal to 5, the maximum slope of the first part is less than or equal to 12000, and the standard deviation of the second part is less than 15.
2. A system for quantitatively analyzing post-fracture complexity to achieve the method of claim 1, wherein: the system comprises:
the curve drawing unit is used for drawing a GdP/dG curve according to the fracturing construction second point data;
an abscissa adjusting unit connected with the graph drawing unit for adjusting the range of the abscissa of the GdP/dG graph output by the graph drawing unit to be between [0,0.1 ];
the wave crest count unit is connected with the abscissa adjustment unit and used for obtaining the wave crest number on the GdP/dG curve;
the maximum slope calculation unit is connected with the abscissa adjustment unit and is used for obtaining the maximum slope of the first part;
the standard deviation calculation unit is connected with the abscissa adjustment unit and is used for obtaining the standard deviation of the second part;
the crack complexity judging unit is respectively connected with the wave crest number counting unit, the maximum slope calculating unit and the standard deviation calculating unit and is used for judging the crack complexity according to the wave crest number, the maximum slope of the first part and the standard deviation of the second part.
3. The system for quantitative analysis of post-fracture complexity according to claim 2, wherein: the maximum slope calculating unit reads the ordinate H corresponding to the highest point of the first part from the data of the GdP/dG curve output by the abscissa adjusting unit max Abscissa T max The maximum slope k of the first portion is then calculated using the following equation:
4. a system for quantitatively analyzing post-fracture complexity according to claim 3, wherein: the standard deviation calculating unit reads the ordinate of each data point of the second part from the data of the GdP/dG curve output by the abscissa adjusting unit, and then calculates the standard deviation of the second part by using the following formula:
wherein; sigma is the standard deviation, S is the variance,is the average value of the ordinate of the second part, x i Is the ordinate of each data point in the second portion, i=1, 2 3.n; n is the number of data points of the second portion.
5. The system for quantitatively analyzing post-fracture complexity of claim 4, wherein: the crack complexity judging unit is used for:
if three first-class complex judging conditions are met at the same time, judging that the first-class complex is obtained;
if any one of three judgment conditions of four-class complexity is satisfied, judging that the four-class complexity is achieved;
if the two-level complex three judging conditions are met at the same time, judging that the two-level complex is achieved; if one or two of the three first-class complex judgment conditions are met and the other two second-class complex judgment conditions are met, judging that the two second-class complex judgment conditions are met;
if three complex judging conditions are met at the same time, judging that the three complex judging conditions are three complex; if one or two of the three first-class complex judgment conditions are met and the other three first-class complex judgment conditions are met, judging that the first-class complex judgment conditions are three first-class complex; if one of three first-class complex judgment conditions is met, one of three second-class complex judgment conditions is met, and one of three third-class complex judgment conditions is met, judging as three third-class complex; if one or two of the second-class complex judgment conditions are satisfied, the other of the second-class complex judgment conditions are satisfied, the judgment is made as third-class complex.
6. A computer-readable storage medium, characterized by: the computer readable storage medium stores at least one program executable by a computer, which when executed by the computer, causes the computer to perform the steps in the method of quantitatively analyzing post-fracture complexity of claim 1.
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