A method, device and readable storage medium for evaluating the uniformity of oil and gas fracturing

Abstract

The present invention discloses a method, device and readable storage medium for evaluating the uniformity of oil and gas fracturing. The method includes: obtaining four groups of potential difference data collected by a first parallel survey line, a second parallel survey line, a first vertical survey line and a second vertical survey line; the first parallel survey line and the second parallel survey line are arranged in parallel, the first vertical survey line and the second vertical survey line are both perpendicular to the first parallel survey line, and the first parallel survey line and the second parallel survey line are both arranged in parallel along the horizontal well section of the wellbore; determining the planar sweep range of the fracturing fluid swept body according to the four groups of potential difference data, and the planar sweep range includes a horizontal sweep surface and a vertical sweep surface; obtaining an evaluation result of vertical fracturing uniformity according to the vertical sweep surface; and obtaining an evaluation result of horizontal fracturing uniformity according to the horizontal sweep surface. The method for evaluating the uniformity of oil and gas fracturing in the embodiments of the present invention can solve the problems of high cost of traditional monitoring methods and inability to accurately analyze and interpret the uniformity of reservoir fracturing reconstruction.

Description

Technical Field

[0001] The present invention relates to the technical field related to oil and gas fracturing, and in particular to a method, device and readable storage medium for evaluating the uniformity of oil and gas fracturing. Background Art

[0002] In the oil field, fracturing refers to a method of forming fractures in an oil or gas reservoir by using hydraulic action during the process of oil or gas production, also known as hydraulic fracturing. The principle of hydraulic fracturing is to use a high-pressure pump on the ground to inject a fracturing fluid with a relatively high viscosity into the oil reservoir through the wellbore. When the injection rate of the fracturing fluid exceeds the absorption capacity of the oil reservoir, a very high pressure is formed on the bottom oil reservoir of the well. When this pressure exceeds the fracture stress of the oil reservoir rock near the bottom of the well, the oil reservoir will be fractured and cracks will be generated. At this time, continue to inject the fracturing fluid into the oil reservoir continuously, and the cracks will continue to expand into the interior of the oil reservoir. In order to keep the fractured cracks in an open state, a sand-carrying fluid with a proppant (usually quartz sand) is then injected into the oil reservoir. After the sand-carrying fluid enters the cracks, on the one hand, it can make the cracks continue to extend forward, and on the other hand, it can support the already fractured cracks so that they will not close. Then, a displacement fluid is injected to displace all the sand-carrying fluid in the wellbore into the cracks and support the cracks with quartz sand. Finally, the injected high-viscosity fracturing fluid will automatically degrade and be discharged outside the wellbore, leaving one or more cracks with different lengths, widths and heights in the oil reservoir, and establishing a new fluid channel between the oil reservoir and the wellbore. After fracturing, the production of oil and gas wells generally increases significantly.

[0003] When fracturing measures are carried out on oil and gas wells, corresponding technical means are required to detect the fracturing wave propagation results in order to obtain many information such as the fracturing fluid wave propagation characteristics, the expansion morphology, complexity and orientation of the fracturing-induced cracks. However, at present, the traditional fracturing monitoring methods have high costs, and the monitoring results cannot accurately analyze and interpret the uniformity of reservoir fracturing transformation. Summary of the Invention

[0004] The present invention aims to at least solve one of the technical problems existing in the prior art. For this purpose, the present invention provides a method for evaluating the uniformity of oil and gas fracturing, which can solve the problems of high cost of traditional monitoring methods and inability to accurately analyze and interpret the uniformity of reservoir fracturing transformation.

[0005] The present invention also provides an apparatus for evaluating the uniformity of oil and gas fracturing and a computer-readable storage medium.

[0006] The method for evaluating the uniformity of oil and gas fracturing according to the first aspect embodiment of the present invention includes the following steps:

[0007] Obtain four groups of potential difference data collected by the first parallel survey line, the second parallel survey line, the first vertical survey line, and the second vertical survey line respectively; the first parallel survey line, the second parallel survey line, the first vertical survey line, and the second vertical survey line are all arranged on the ground above the fracturing fluid affected body, the first parallel survey line and the second parallel survey line are arranged in parallel, the first vertical survey line and the second vertical survey line are both perpendicular to the first parallel survey line, and the first parallel survey line and the second parallel survey line are both arranged in parallel along the horizontal well section of the wellbore;

[0008] Determine the planar sweep range of the fracturing fluid affected body parallel to the ground according to the four groups of potential difference data, and the planar sweep range at least includes a horizontal sweep surface and a vertical sweep surface perpendicular to the extension direction of the horizontal sweep surface;

[0009] Obtain the vertical fracturing uniformity evaluation result according to the vertical sweep surface;

[0010] Obtain the horizontal fracturing uniformity evaluation result according to the horizontal sweep surface.

[0011] According to the oil and gas fracturing uniformity evaluation method of the embodiments of the present invention, it has at least the following beneficial effects:

[0012] By obtaining four groups of potential difference data collected by the first parallel survey line, the second parallel survey line, the first vertical survey line, and the second vertical survey line respectively, the planar sweep range of the fracturing fluid affected body parallel to the ground can be determined. Among them, the vertical sweep surface of the fracturing fluid affected body can be determined according to the two groups of potential difference data collected by the first parallel survey line and the second parallel survey line; according to the two groups of potential difference data collected by the first vertical survey line and the second vertical survey line, the horizontal sweep surface of the fracturing fluid affected body can be determined. The horizontal fracturing uniformity evaluation result can be analyzed according to the horizontal sweep surface, and the vertical fracturing uniformity evaluation result can be analyzed according to the vertical sweep surface. The oil and gas fracturing uniformity evaluation method of the embodiments of the present invention determines the horizontal sweep surface and the vertical sweep surface of the fracturing fluid affected body through four groups of potential difference data collected by the first parallel survey line, the second parallel survey line, the first vertical survey line, and the second vertical survey line, so as to obtain the horizontal fracturing uniformity evaluation result in the horizontal direction and the vertical fracturing uniformity evaluation result in the vertical direction through the analysis of the horizontal sweep surface and the vertical sweep surface. Compared with the traditional monitoring method, the monitoring cost is low, and the problem that the detection results obtained by the traditional monitoring method cannot accurately analyze and interpret the uniformity of reservoir fracturing transformation is solved.

[0013] According to some embodiments of the present invention, the obtaining the vertical fracturing uniformity evaluation result according to the vertical sweep surface includes the following steps:

[0014] Select N first ranging points at the edge of the vertical wave-affected surface on one side of the wellbore, and calculate the first wave-affected distance values from the N first ranging points to the wellbore;

[0015] Select N second ranging points at the edge of the vertical wave-affected surface on the other side of the wellbore, and calculate the second wave-affected distance values from the N second ranging points to the wellbore;

[0016] Generate a first wave-affected characteristic curve based on multiple first wave-affected distance values;

[0017] Generate a second wave-affected characteristic curve based on multiple second wave-affected distance values;

[0018] Obtain the vertical fracturing uniformity evaluation result based on the first wave-affected characteristic curve and the second wave-affected characteristic curve.

[0019] According to some embodiments of the present invention, the obtaining of the vertical fracturing uniformity evaluation result based on the first wave-affected characteristic curve and the second wave-affected characteristic curve includes the following steps:

[0020] Determine the first sample fluctuation parameter of the first wave-affected characteristic curve, and the first sample fluctuation parameter characterizes the dispersion degree of the first wave-affected characteristic curve;

[0021] Determine the second sample fluctuation parameter of the second wave-affected characteristic curve, and the second sample fluctuation parameter characterizes the dispersion degree of the second wave-affected characteristic curve;

[0022] Obtain the vertical fracturing uniformity evaluation result based on the first sample fluctuation parameter and the second sample fluctuation parameter.

[0023] According to some embodiments of the present invention, the obtaining of the horizontal fracturing uniformity evaluation result based on the horizontal wave-affected surface includes the following steps:

[0024] Select N third ranging points at the edge of the horizontal wave-affected surface on one side of the perpendicular bisector of the wellbore, and calculate the third wave-affected distance values from the N third ranging points to the wellbore;

[0025] Select N fourth ranging points at the edge of the horizontal wave-affected surface on the other side of the perpendicular bisector, and calculate the fourth wave-affected distance values from the N fourth ranging points to the wellbore;

[0026] Generate a third wave-affected characteristic curve based on multiple third wave-affected distance values;

[0027] Generate a fourth wave-affected characteristic curve based on multiple fourth wave-affected distance values;

[0028] The horizontal fracturing uniformity evaluation result is obtained based on the third wave and its characteristic curve and the fourth wave and its characteristic curve.

[0029] According to some embodiments of the present invention, the step of obtaining the horizontal fracturing uniformity evaluation result based on the third wave and its characteristic curve and the fourth wave and its characteristic curve includes the following steps:

[0030] Determine the third sample fluctuation parameter of the third wave and its characteristic curve, where the third sample fluctuation parameter characterizes the dispersion degree of the third wave and its characteristic curve;

[0031] Determine the fourth sample fluctuation parameter of the fourth wave and its characteristic curve, where the fourth sample fluctuation parameter characterizes the dispersion degree of the fourth wave and its characteristic curve;

[0032] Obtain the horizontal fracturing uniformity evaluation result based on the third sample fluctuation parameter and the fourth sample fluctuation parameter.

[0033] According to some embodiments of the present invention, the first sample fluctuation parameter includes the mean value, variance, and range.

[0034] According to some embodiments of the present invention, the four groups of potential difference data are obtained by the following steps:

[0035] Lay the first parallel survey line, the second parallel survey line, the first vertical survey line, and the second vertical survey line on the ground above the fracturing fluid affected body. Among them, the first parallel survey line and the second parallel survey line are arranged in parallel, the first vertical survey line and the second vertical survey line are both perpendicular to the first parallel survey line, and the first parallel survey line and the second parallel survey line are both arranged parallel to the horizontal well section of the wellbore;

[0036] Output a test electrical signal to the wellbore and inject fracturing fluid into the wellbore to respectively obtain the four groups of potential difference data collected by the first parallel survey line, the second parallel survey line, the first vertical survey line, and the second vertical survey line.

[0037] According to some embodiments of the present invention, the step of determining the planar affected range of the fracturing fluid affected body parallel to the ground based on the four groups of potential difference data includes the following steps:

[0038] Subtract each of the potential difference data collected by the first parallel survey line, the second parallel survey line, the first vertical survey line, and the second vertical survey line from the original background field data one by one to obtain four groups of optimized potential data. The original background field data is measured by the first parallel survey line, the second parallel survey line, the first vertical survey line, and the second vertical survey line when the fracturing fluid affected body has not been fractured in the wellbore;

[0039] Determine the planar sweep range of the fracturing fluid swept body parallel to the ground according to the four groups of the optimized potential data.

[0040] An oil and gas fracturing uniformity evaluation device according to an embodiment of the second aspect of the present invention includes:

[0041] A cross-shaped monitoring structure arranged above the ground of the fracturing fluid swept body. The cross-shaped monitoring structure at least includes a first parallel survey line and a second parallel survey line arranged parallel to each other, and a first vertical survey line and a second vertical survey line both perpendicular to the first parallel survey line. The first parallel survey line and the second parallel survey line are both arranged parallel to the horizontal well section of the wellbore;

[0042] A signal transmitting system for outputting a test electrical signal to the wellbore;

[0043] A signal receiving system for receiving four groups of potential difference data collected by the first parallel survey line, the second parallel survey line, the first vertical survey line, and the second vertical survey line;

[0044] A data processing system for executing the oil and gas fracturing uniformity evaluation method as described in the embodiment of the first aspect above.

[0045] The oil and gas fracturing uniformity evaluation device according to the embodiment of the present invention has at least the following beneficial effects:

[0046] By arranging the cross-shaped monitoring structure, the electric field data formed by the fracturing fluid swept body can be monitored, so that the planar sweep range of the fracturing fluid swept body parallel to the ground can be determined through four groups of potential difference data collected by the first parallel survey line, the second parallel survey line, the first vertical survey line, and the second vertical survey line. Among them, the vertical sweep surface of the fracturing fluid swept body can be determined according to the two groups of potential difference data collected by the first parallel survey line and the second parallel survey line; the planar sweep range at least includes a horizontal sweep surface and a vertical sweep surface. The horizontal fracturing uniformity evaluation result can be analyzed according to the horizontal sweep surface, and the vertical fracturing uniformity evaluation result can be analyzed according to the vertical sweep surface. The monitoring method of the oil and gas fracturing uniformity evaluation device in the embodiment of the present invention is simple and low in cost. Through the four groups of potential difference data collected by the first parallel survey line, the second parallel survey line, the first vertical survey line, and the second vertical survey line, the horizontal sweep surface and the vertical sweep surface of the fracturing fluid swept body can be determined, so that the horizontal fracturing uniformity evaluation result in the horizontal direction and the vertical fracturing uniformity evaluation result in the vertical direction can be obtained through the analysis of the horizontal sweep surface and the vertical sweep surface, solving the problem that the detection results obtained by the traditional monitoring method cannot accurately analyze and interpret the uniformity of reservoir fracturing transformation.

[0047] A computer-readable storage medium according to an embodiment of the third aspect of the present invention stores computer-executable instructions for executing the method for evaluating the uniformity of oil and gas fracturing as described in the embodiment of the first aspect above. Since the computer-readable storage medium adopts all the technical solutions of the method for evaluating the uniformity of oil and gas fracturing in the above embodiment, it has at least all the beneficial effects brought by the technical solutions of the above embodiment.

[0048] Other features and advantages of the present invention will be described in the following description of the specification, and in part will be obvious from the description of the specification, or will be understood by implementing the present invention. Description of the Drawings

[0049] The above and / or additional aspects and advantages of the present invention will become obvious and easy to understand from the description of the embodiments in conjunction with the following drawings, where:

[0050] Figure 1 is a schematic layout diagram of the grid-shaped monitoring structure according to an embodiment of the present invention;

[0051] Figure 2 is a graph of the first wave characteristic curve and the second wave characteristic curve according to an embodiment of the present invention;

[0052] Figure 3 is a flowchart of the method for evaluating the uniformity of oil and gas fracturing according to an embodiment of the present invention.

[0053] Reference Signs:

[0054] Wellbore 100;

[0055] Monitoring Point 200. Detailed Embodiments

[0056] The embodiments of the present invention will be described in detail below. The examples of the embodiments are shown in the drawings, where the same or similar reference numerals represent the same or similar elements or elements with the same or similar functions from beginning to end. The embodiments described below with reference to the drawings are exemplary and are only used to explain the present invention and should not be construed as a limitation of the present invention.

[0057] In the description of the present invention, if the first, second, etc. are described only for the purpose of distinguishing technical features, it cannot be understood as indicating or implying relative importance or implicitly indicating the quantity of the indicated technical features or implicitly indicating the sequence of the indicated technical features.

[0058] In the description of the present invention, it should be understood that for the orientation description, such as the upper and lower directions, the orientation or positional relationship indicated is based on the orientation or positional relationship shown in the drawings. It is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, it should not be construed as a limitation to the present invention.

[0059] In the description of the present invention, it should be noted that unless otherwise clearly defined, words such as "set", "installed", "connected", etc. should be understood in a broad sense. Those skilled in the art can reasonably determine the specific meanings of the above words in the present invention in combination with the specific content of the technical solution.

[0060] An oil and gas fracturing uniformity evaluation device is provided in an embodiment of the present invention, which includes a cross-shaped monitoring structure, a signal transmitting system, a signal receiving system, and a data processing system. The cross-shaped monitoring structure is arranged on the ground above the fracturing fluid affected body. The cross-shaped monitoring structure at least includes a first parallel survey line and a second parallel survey line that are parallel to each other, and a first vertical survey line and a second vertical survey line that are both perpendicular to the first parallel survey line. The first parallel survey line and the second parallel survey line are both arranged parallel to the horizontal well section of the wellbore 100; the signal transmitting system is used to output a test electrical signal to the wellbore 100; the signal receiving system is used to receive four groups of potential difference data collected by the first parallel survey line, the second parallel survey line, the first vertical survey line, and the second vertical survey line; the data processing system is used to execute the oil and gas fracturing uniformity evaluation method according to the embodiment of the first aspect of the present invention.

[0061] As Figure 1 shown, the first parallel survey line, the second parallel survey line, the first vertical survey line, and the second vertical survey line all include a plurality of monitoring points 200 arranged at equal intervals. Each monitoring point 200 is used to collect the potential difference data between the wellbore 100 and the monitoring point 200. The fracturing fluid affected body is formed by fracturing the fracturing fluid input into the wellbore 100. The wellbore 100 in the embodiment of the present invention uses a horizontal wellbore 100.

[0062] The first parallel survey line, the second parallel survey line, the first vertical survey line, and the second vertical survey line form a "cross-shaped" layout, and the distance between the first parallel survey line and the second parallel survey line, as well as the distance between the first vertical survey line and the second vertical survey line, need to maintain a sufficient distance, and the first parallel survey line, the second parallel survey line, the first vertical survey line, and the second vertical survey line all need to maintain a sufficient length to ensure better monitoring of the electric field change of the entire fracturing fluid affected body.

[0063] According to the method for evaluating the uniformity of oil and gas fracturing according to the embodiments of the present invention, by respectively obtaining four groups of potential difference data collected by the first parallel survey line, the second parallel survey line, the first vertical survey line, and the second vertical survey line, the planar coverage range of the fracturing fluid affected body parallel to the ground can be determined. Among them, according to the two groups of potential difference data collected by the first parallel survey line and the second parallel survey line, the vertical coverage surface of the fracturing fluid affected body can be determined; according to the two groups of potential difference data collected by the first vertical survey line and the second vertical survey line, the horizontal coverage surface of the fracturing fluid affected body can be determined. According to the horizontal coverage surface, the evaluation result of horizontal fracturing uniformity can be analyzed, and according to the vertical coverage surface, the evaluation result of vertical fracturing uniformity can be analyzed. The method for evaluating the uniformity of oil and gas fracturing according to the embodiments of the present invention determines the horizontal coverage surface and the vertical coverage surface of the fracturing fluid affected body through four groups of potential difference data collected by the first parallel survey line, the second parallel survey line, the first vertical survey line, and the second vertical survey line, so as to obtain the evaluation result of horizontal fracturing uniformity in the horizontal direction and the evaluation result of vertical fracturing uniformity in the vertical direction through the analysis of the horizontal coverage surface and the vertical coverage surface. Compared with the traditional monitoring method, the monitoring cost is low, and the problem that the detection result obtained by the traditional monitoring method cannot accurately analyze and explain the uniformity of reservoir fracturing transformation is solved.

[0064] The following will be combined with Figures 1 to 3 to clearly and completely describe the method for evaluating the uniformity of oil and gas fracturing according to the embodiments of the present invention. Obviously, the following described embodiments are some embodiments of the present invention, not all embodiments.

[0065] The method for evaluating the uniformity of oil and gas fracturing according to the first aspect embodiment of the present invention includes the following steps:

[0066] Respectively obtain four groups of potential difference data collected by the first parallel survey line, the second parallel survey line, the first vertical survey line, and the second vertical survey line; the first parallel survey line, the second parallel survey line, the first vertical survey line, and the second vertical survey line are all arranged above the ground of the fracturing fluid affected body. The first parallel survey line and the second parallel survey line are arranged in parallel, the first vertical survey line and the second vertical survey line are both perpendicular to the first parallel survey line, and the first parallel survey line and the second parallel survey line are both arranged in parallel along the horizontal well section of the wellbore 100;

[0067] Determine the planar coverage range of the fracturing fluid affected body parallel to the ground according to the four groups of potential difference data. The planar coverage range at least includes a horizontal coverage surface and a vertical coverage surface perpendicular to the extension direction of the horizontal coverage surface;

[0068] Obtain the evaluation result of vertical fracturing uniformity according to the vertical coverage surface;

[0069] Obtain the evaluation result of horizontal fracturing uniformity according to the horizontal coverage surface.

[0070] The length, width, and height of the fracturing fluid affected body can be determined through four sets of potential difference data, and thus the affected area, affected volume, affected width, and planar affected range of the fracturing fluid affected body can be determined. In the embodiments of the present invention, the fracturing uniformity of the fracturing fluid affected body is mainly analyzed based on the planar affected range. It should be noted that the morphological data of the fracturing fluid affected body can be obtained through potential difference data, which is prior art known to those skilled in the art and will not be elaborated herein.

[0071] The plane referred to by the planar affected range passes through the wellbore 100. The planar affected range includes at least a horizontal affected plane and a vertical affected plane perpendicular to the extension direction of the horizontal affected plane. Among them, the vertical affected plane can be understood as the direction in which the fracturing fluid affected body extends perpendicular to the wellbore 100, and the horizontal affected plane can be understood as the direction in which the fracturing fluid affected body extends parallel to the wellbore 100. The vertical affected plane can be further decomposed into two first sub-affected planes on both sides of the wellbore 100. By analyzing the affected distances of the edges far from the wellbore 100 on the two first sub-affected planes, the uniformity of the two first sub-affected planes can be known, and thus the vertical fracturing uniformity evaluation result can be obtained based on the vertical affected plane. The horizontal affected plane can be further decomposed into two second sub-affected planes on both sides of the perpendicular bisector of the wellbore 100. By analyzing the affected distances of the edges far from the perpendicular bisector on the two second sub-affected planes, the uniformity of the two second sub-affected planes can be known, and thus the horizontal fracturing uniformity evaluation result can be obtained based on the horizontal affected plane.

[0072] It should be noted that the plane referred to by the planar affected range may not pass through the wellbore 100, and the principle of calculating subsequent distance values can be correspondingly deduced and will not be elaborated herein.

[0073] In some embodiments of the present invention, referring to Figure 1 and Figure 2 , obtaining the vertical fracturing uniformity evaluation result based on the vertical affected plane includes the following steps:

[0074] Select N first ranging points at the edge of the vertical affected plane on one side of the wellbore 100, and calculate the first affected distance values of the N first ranging points to the wellbore 100;

[0075] Select N second ranging points at the edge of the vertical affected plane on the other side of the wellbore 100, and calculate the second affected distance values of the N second ranging points to the wellbore 100;

[0076] Generate a first affected characteristic curve L1 based on the multiple first affected distance values;

[0077] Generate a second affected characteristic curve L2 based on the multiple second affected distance values;

[0078] Obtain the vertical fracturing uniformity evaluation result based on the first affected characteristic curve L1 and the second affected characteristic curve L2.

[0079] The first wave characteristic curve L1 generated based on multiple first wave and distance values reflects the fracturing change pattern at the edge of the vertical wave surface on one side of the wellbore 100. The second wave characteristic curve L2 generated based on multiple second wave and distance values reflects the fracturing change pattern at the edge of the vertical wave surface on the other side of the wellbore 100. By analyzing the curve uniformity of the first wave characteristic curve L1 and the second wave characteristic curve L2, the uniformity degree of the edges of the vertical wave surface on both sides of the wellbore 100 can be reflected, and the vertical fracturing uniformity evaluation result can be obtained, so as to know on which side of the wellbore 100 the edge part of the vertical wave surface is more uniform.

[0080] In some embodiments of the present invention, referring to Figure 2 , obtaining the vertical fracturing uniformity evaluation result according to the first wave characteristic curve L1 and the second wave characteristic curve L2 includes the following steps:

[0081] Determine the first sample fluctuation parameter of the first wave characteristic curve L1, and the first sample fluctuation parameter characterizes the dispersion degree of the first wave characteristic curve L1;

[0082] Determine the second sample fluctuation parameter of the second wave characteristic curve L2, and the second sample fluctuation parameter characterizes the dispersion degree of the second wave characteristic curve L2;

[0083] Obtain the vertical fracturing uniformity evaluation result according to the first sample fluctuation parameter and the second sample fluctuation parameter.

[0084] Both the first sample fluctuation parameter and the second sample fluctuation parameter characterize the dispersion degree of the curve. The first wave characteristic curve L1 reflects the fracturing change pattern at the edge of the vertical wave surface on one side of the wellbore 100, and the second wave characteristic curve L2 reflects the fracturing change pattern at the edge of the vertical wave surface on the other side of the wellbore 100. By determining the dispersion degree of the first wave characteristic curve L1 through the first sample fluctuation parameter and the dispersion degree of the second wave characteristic curve L2 through the second sample fluctuation parameter, the uniformity degree of the edges of the vertical wave surface on both sides of the wellbore 100 can be reflected, and the vertical fracturing uniformity evaluation result can be obtained, so as to know on which side of the wellbore 100 the edge part of the vertical wave surface is more uniform. It should be noted that as long as the first sample fluctuation parameter and the second sample fluctuation parameter can reflect the curve dispersion degree, they can be a parameter or a parameter group combined by multiple parameters, which cannot be regarded as a limitation to the present invention.

[0085] In some embodiments of the present invention, referring to Figure 1 and Figure 2 , obtaining the horizontal fracturing uniformity evaluation result according to the horizontal wave surface includes the following steps:

[0086] Select N third ranging points on the edge of the horizontal sweep plane on one side of the perpendicular bisector of the wellbore 100, and calculate the third sweep distance values of the N third ranging points to the wellbore 100;

[0087] Select N fourth ranging points on the edge of the horizontal sweep plane on the other side of the perpendicular bisector, and calculate the fourth sweep distance values of the N fourth ranging points to the wellbore 100;

[0088] Generate a third sweep characteristic curve L3 based on multiple third sweep distance values;

[0089] Generate a fourth sweep characteristic curve L4 based on multiple fourth sweep distance values;

[0090] Obtain the horizontal fracturing uniformity evaluation result based on the third sweep characteristic curve L3 and the fourth sweep characteristic curve L4.

[0091] The third sweep characteristic curve L3 generated based on multiple third sweep distance values reflects the fracturing change pattern at the edge of the horizontal sweep plane on one side of the perpendicular bisector of the wellbore 100, and the fourth sweep characteristic curve L4 generated based on multiple fourth sweep distance values reflects the fracturing change pattern at the edge of the horizontal sweep plane on the other side of the perpendicular bisector. By analyzing the curve uniformity of the third sweep characteristic curve L3 and the fourth sweep characteristic curve L4, the uniformity degree at the edges of both sides of the perpendicular bisector of the wellbore 100 can be reflected, and the horizontal fracturing uniformity evaluation result can be obtained, so as to know on which side of the perpendicular bisector of the wellbore 100 the edge part of the horizontal sweep plane is more uniform.

[0092] In some embodiments of the present invention, refer to Figure 2 , obtaining the horizontal fracturing uniformity evaluation result based on the third sweep characteristic curve L3 and the fourth sweep characteristic curve L4 includes the following steps:

[0093] Determine the third sample fluctuation parameter of the third sweep characteristic curve L3, and the third sample fluctuation parameter characterizes the dispersion degree of the third sweep characteristic curve L3;

[0094] Determine the fourth sample fluctuation parameter of the fourth sweep characteristic curve L4, and the fourth sample fluctuation parameter characterizes the dispersion degree of the fourth sweep characteristic curve L4;

[0095] Obtain the horizontal fracturing uniformity evaluation result according to the third sample fluctuation parameter and the fourth sample fluctuation parameter.

[0096] The third sample fluctuation parameter and the fourth sample fluctuation parameter both characterize the degree of dispersion of the curve. The third wave and characteristic curve L3 reflects the fracturing change pattern of the edge of the horizontal wave front on one side of the perpendicular bisector of the wellbore 100, and the fourth wave and characteristic curve L4 reflects the fracturing change pattern of the edge of the horizontal wave front on the other side of the perpendicular bisector. By determining the degree of dispersion of the third wave and characteristic curve L3 through the third sample fluctuation parameter and the degree of dispersion of the fourth wave and characteristic curve L4 through the fourth sample fluctuation parameter, the uniformity of the edges of the horizontal wave front on both sides of the perpendicular bisector of the wellbore 100 can be reflected, and the evaluation result of the horizontal fracturing uniformity can be obtained, so as to know on which side of the perpendicular bisector of the wellbore 100 the edge part of the horizontal wave front is more uniform. It should be noted that the third sample fluctuation parameter and the fourth sample fluctuation parameter only need to be able to reflect the degree of curve dispersion, which can be a single parameter or a parameter group combined by multiple parameters, and should not be regarded as a limitation of the present invention.

[0097] In some embodiments of the present invention, the first sample fluctuation parameter includes the mean value, variance, and range. The second sample fluctuation parameter, the third sample fluctuation parameter, and the fourth sample fluctuation parameter all include the mean value, variance, and range. The mean value, variance, and range are all parameters reflecting the degree of dispersion of the curve. By analyzing the first wave and characteristic curve L1 and the second wave and characteristic curve L2 in combination with these three parameters, the uniformity of the vertical wave front on both sides of the wellbore 100 can be known; by analyzing the third wave and characteristic curve L3 and the fourth wave and characteristic curve L4 in combination with these three parameters, the uniformity of the horizontal wave front on both sides of the perpendicular bisector of the wellbore 100 can be known.

[0098] In some embodiments, the constraint formula for the mean value of the first wave and characteristic curve L1 is:

[0099]

[0100] The constraint formula for the variance of the first wave and characteristic curve L1 is:

[0101]

[0102] The constraint formula for the range of the first wave and characteristic curve L1 is:

[0103] R = f(x) max -f(x) min ;

[0104] Wherein, is the mean value, a and b are the positions of both ends of the wave length of the fracturing fluid wave body respectively, μ is the sampling point selection interval, and f(x) is the first wave and characteristic curve L1.

[0105] It should be noted that the above formula is also applicable to the second wave and its characteristic curve L2, the third wave and its characteristic curve L3, and the fourth wave and its characteristic curve L4.

[0106] To better illustrate the advantages of the oil and gas fracturing uniformity evaluation method according to the embodiments of the present invention, a specific embodiment will be described in detail below.

[0107] Taking the first wave and its characteristic curve L1 and the second wave and its characteristic curve L2 as examples, as Figure 1 and Figure 2 shown, the first wave and its characteristic curve L1 and the second wave and its characteristic curve L2 are two curves distributed on both sides of the wellbore 100. Sampling point information is obtained at intervals of 0.5 m, and the variance, average value, and range of the first wave and its characteristic curve L1 and the second wave and its characteristic curve L2 are calculated respectively. For the convenience of observation and calculation, the results of the second wave and its characteristic curve L2 are assigned negative values, that is, the negative sign in the results represents the direction. As shown in Table 1, the swept areas on both sides of the wellbore 100 are close, the results are not much different, and the difference in the average values does not exceed 10%. However, the range of the first wave and its characteristic curve L1 can reach 161.55 m, which is nearly 50 m longer than that of the second wave and its characteristic curve L2. From the perspective of variance, the variance of the first wave and its characteristic curve L1 is 45.78, while that of the second wave and its characteristic curve L2 is only 25.80, indicating that the second wave and its characteristic curve L2 have a small degree of dispersion, the reservoir stimulation is more uniform, and the fracturing effect is relatively better.

[0108] Table 1 Sample fluctuation parameters

[0109] Area Average value Range Variance L1 8442.27 76.75 161.55 45.78 L2 7732.60 -70.30 115.65 25.80

[0110] It should be noted that the evaluation process of the fracturing uniformity of the third wave and its characteristic curve L3 and the fourth wave and its characteristic curve L4 is the same as the above process, and will not be elaborated here.

[0111] In some embodiments of the present invention, referring to Figure 1 , the four groups of potential difference data are obtained by the following steps:

[0112] A first parallel survey line, a second parallel survey line, a first vertical survey line, and a second vertical survey line are arranged on the ground above the fracturing fluid swept body. Among them, the first parallel survey line and the second parallel survey line are arranged in parallel, the first vertical survey line and the second vertical survey line are both perpendicular to the first parallel survey line, and the first parallel survey line and the second parallel survey line are both arranged parallel to the horizontal well section of the wellbore 100;

[0113] A test electrical signal is output to the wellbore 100, and fracturing fluid is injected into the wellbore 100 to obtain four groups of potential difference data collected by the first parallel survey line, the second parallel survey line, the first vertical survey line, and the second vertical survey line respectively.

[0114] The first parallel survey line, the second parallel survey line, the first vertical survey line, and the second vertical survey line all include a plurality of monitoring points 200 arranged at equal intervals. Each monitoring point 200 is used to collect the potential difference data between the wellbore 100 and the monitoring point 200. After outputting a test electrical signal to the wellbore 100 and injecting fracturing fluid into the wellbore 100, a set of potential difference data can be detected by the plurality of monitoring points 200 arranged at equal intervals on each survey line.

[0115] In some embodiments of the present invention, with reference to Figure 1 , to determine the planar coverage range of the fracturing fluid body parallel to the ground according to four sets of potential difference data, the following steps are included:

[0116] Subtract each potential difference data collected by the first parallel survey line, the second parallel survey line, the first vertical survey line, and the second vertical survey line from the original background field data one by one to obtain four sets of optimized potential data. The original background field data is measured by the first parallel survey line, the second parallel survey line, the first vertical survey line, and the second vertical survey line when no fracturing fluid body is fractured out in the wellbore 100;

[0117] Determine the planar coverage range of the fracturing fluid body parallel to the ground according to the four sets of optimized potential data.

[0118] The acquisition of the original background field data can be carried out when fracturing fluid is injected into the wellbore 100 but no fracturing fluid body has been formed yet. After the electric field stabilizes, select a stable electric field within a period of time as the background field, and calculate the average value of each potential data collected by the first parallel survey line, the second parallel survey line, the first vertical survey line, and the second vertical survey line during this period respectively, and set the average value as the original background field data. By eliminating the influence of the original background field data, the detection error caused by non-fracturing fluid itself can be excluded as much as possible, making the planar coverage range more accurate.

[0119] Next, the oil and gas fracturing uniformity evaluation device of the embodiments of the present invention will be described clearly and completely in conjunction with Figures 1 to 3 . Obviously, the following described embodiments are part of the embodiments of the present invention, not all embodiments.

[0120] An oil and gas fracturing uniformity evaluation device according to an embodiment of the second aspect of the present invention includes a well-shaped monitoring structure, a signal transmitting system, a signal receiving system, and a data processing system. The well-shaped monitoring structure is arranged on the ground above the fracturing fluid affected body. The well-shaped monitoring structure at least includes a first parallel survey line and a second parallel survey line that are parallel to each other, and a first vertical survey line and a second vertical survey line that are both perpendicular to the first parallel survey line. The first parallel survey line and the second parallel survey line are both arranged parallel to the horizontal well section of the wellbore 100; the signal transmitting system is used to output a test electrical signal to the wellbore 100; the signal receiving system is used to receive four groups of potential difference data collected by the first parallel survey line, the second parallel survey line, the first vertical survey line, and the second vertical survey line; the data processing system is used to execute the oil and gas fracturing uniformity evaluation method according to the embodiment of the first aspect of the present invention.

[0121] As Figure 1 shown, the first parallel survey line, the second parallel survey line, the first vertical survey line, and the second vertical survey line each include a plurality of monitoring points 200 arranged at equal intervals. Each monitoring point 200 is used to collect potential difference data between the wellbore 100 and the monitoring point 200. The fracturing fluid affected body is formed by fracturing the fracturing fluid input into the wellbore 100. The wellbore 100 in the embodiment of the present invention uses a horizontal wellbore 100.

[0122] The first parallel survey line, the second parallel survey line, the first vertical survey line, and the second vertical survey line form a "well-shaped" layout, and the distance between the first parallel survey line and the second parallel survey line, as well as the distance between the first vertical survey line and the second vertical survey line, need to maintain a sufficient distance, and the first parallel survey line, the second parallel survey line, the first vertical survey line, and the second vertical survey line all need to maintain a sufficient length to ensure better monitoring of the electric field changes of the entire fracturing fluid affected body.

[0123] The data processing system can determine the length, width, and height of the fracturing fluid affected body through the four groups of potential difference data received by the signal receiving system, thereby determining the affected area, affected volume, affected width, and planar affected range of the fracturing fluid affected body. The embodiment of the present invention mainly analyzes the fracturing uniformity of the fracturing fluid affected body according to the planar affected range. It should be noted that the morphological data of the fracturing fluid affected body can be obtained through the potential difference data, which is prior art known to those skilled in the art and will not be elaborated here.

[0124] The plane referred to by the plane wave propagation range passes through the wellbore 100. The plane wave propagation range includes at least a horizontal wave propagation surface and a vertical wave propagation surface perpendicular to the extension direction of the horizontal wave propagation surface. Among them, the vertical wave propagation surface can be understood as the propagation direction of the fracturing fluid wave body being perpendicular to the wellbore 100, and the horizontal wave propagation surface can be understood as the propagation direction of the fracturing fluid wave body being parallel to the wellbore 100. The vertical wave propagation surface can be further decomposed into two first sub-wave propagation surfaces on both sides of the wellbore 100. By analyzing the propagation distances of the edges far from the wellbore 100 on the two first sub-wave propagation surfaces, the uniformity of the two first sub-wave propagation surfaces can be obtained, and thus the vertical fracturing uniformity evaluation result can be obtained based on the vertical wave propagation surface. The horizontal wave propagation surface can be further decomposed into two second sub-wave propagation surfaces on both sides of the perpendicular bisector of the wellbore 100. By analyzing the propagation distances of the edges far from the perpendicular bisector on the two second sub-wave propagation surfaces, the uniformity of the two second sub-wave propagation surfaces can be obtained, and thus the horizontal fracturing uniformity evaluation result can be obtained based on the horizontal wave propagation surface.

[0125] It should be noted that the monitoring points 200 can directly use metal electrodes, such as metal copper rods, iron rods, etc. The signal transmission system can use an alternating current transmitter or other equipment that can send out alternating current signals. The signal receiving system needs to include multiple analog-to-digital conversion channels to convert the potential difference data collected by multiple monitoring points 200 into digital signals, so as to facilitate subsequent analysis by the data processing system. The data processing system can directly use a server to provide sufficient computing power. It should also be noted that the signal receiving system has a grounding terminal, and the grounding terminal is electrically connected to the wellbore 100. After multiple monitoring points 200 are connected to the signal receiving system, it is convenient to unify the data collected by multiple monitoring points 200, that is, each monitoring point 200 completes the measurement of the potential difference data between the wellbore 100 and itself.

[0126] The oil and gas fracturing uniformity evaluation device according to an embodiment of the present invention can monitor the electric field data formed by the fracturing fluid affected body by arranging a cross-shaped monitoring structure, so that the planar coverage range of the fracturing fluid affected body parallel to the ground can be determined through four groups of potential difference data collected by the first parallel survey line, the second parallel survey line, the first vertical survey line, and the second vertical survey line. Among them, the vertical coverage surface of the fracturing fluid affected body can be determined according to the two groups of potential difference data collected by the first parallel survey line and the second parallel survey line; the planar coverage range includes at least a horizontal coverage surface and a vertical coverage surface. The horizontal fracturing uniformity evaluation result can be analyzed according to the horizontal coverage surface, and the vertical fracturing uniformity evaluation result can be analyzed according to the vertical coverage surface. The monitoring method of the oil and gas fracturing uniformity evaluation device according to the embodiment of the present invention is simple and low in cost. Through the four groups of potential difference data collected by the first parallel survey line, the second parallel survey line, the first vertical survey line, and the second vertical survey line, the horizontal coverage surface and the vertical coverage surface of the fracturing fluid affected body can be determined, so that the horizontal fracturing uniformity evaluation result in the horizontal direction and the vertical fracturing uniformity evaluation result in the vertical direction can be obtained through the analysis of the horizontal coverage surface and the vertical coverage surface, solving the problem that the detection results obtained by the traditional monitoring method cannot accurately analyze and interpret the uniformity degree of reservoir fracturing transformation.

[0127] In addition, the data processing system according to an embodiment of the present invention includes: a memory, a processor, and a computer program stored on the memory and executable on the processor. The processor and the memory can be connected through a bus or other means.

[0128] As a non-transitory computer-readable storage medium, the memory can be used to store non-transitory software programs and non-transitory computer-executable programs. In addition, the memory may include a high-speed random access memory, and may also include a non-transitory memory, such as at least one magnetic disk storage device, a flash memory device, or other non-transitory solid-state storage devices. In some embodiments, the memory may optionally include a memory remotely disposed relative to the processor, and these remote memories may be connected to the processor through a network. Examples of the above networks include, but are not limited to, the Internet, an enterprise intranet, a local area network, a mobile communication network, and combinations thereof.

[0129] The non-transitory software programs and instructions required to implement the oil and gas fracturing uniformity evaluation method of the above embodiment are stored in the memory, and when executed by the processor, execute the oil and gas fracturing uniformity evaluation method in the above embodiment.

[0130] The device embodiments described above are merely illustrative. The units described as separate components may or may not be physically separated, that is, they may be located in one place, or may be distributed to multiple network units. Some or all of the modules can be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0131] In addition, an embodiment of the third aspect of the present invention further provides a computer-readable storage medium storing computer-executable instructions, which are executed by a processor or a controller, for example, executed by a processor in the above data processing system, so that the processor can execute the method for evaluating the uniformity of oil and gas fracturing in the above embodiment.

[0132] Those of ordinary skill in the art can understand that all or some of the steps and systems in the methods disclosed above can be implemented as software, firmware, hardware, and their appropriate combinations. Some physical components or all physical components can be implemented as software executed by a processor, such as a central processing unit, a digital signal processor, or a microprocessor, or as hardware, or as an integrated circuit, such as an application-specific integrated circuit. Such software can be distributed on a computer-readable medium, which can include a computer storage medium (or non-transitory medium) and a communication medium (or transitory medium). As is well known to those of ordinary skill in the art, the term computer storage medium includes volatile and non-volatile, removable and non-removable media implemented in any method or technology for storing information, such as computer-readable instructions, data structures, program modules, or other data. Computer storage media include, but are not limited to, RAM, ROM, EEPROM, flash memory or other memory technologies, CD-ROM, digital versatile disk (DVD) or other optical disk storage, magnetic cassette, tape, magnetic disk storage or other magnetic storage devices, or any other medium that can be used to store the desired information and can be accessed by a computer. In addition, as is well known to those of ordinary skill in the art, a communication medium typically contains computer-readable instructions, data structures, program modules, or other data in a modulated data signal such as a carrier wave or other transmission mechanism, and can include any information delivery medium.

[0133] The embodiments of the present invention have been described in detail above with reference to the accompanying drawings. However, the present invention is not limited to the above embodiments, and various changes can be made without departing from the spirit of the present invention within the scope of knowledge possessed by those of ordinary skill in the relevant art.

Claims

1. An evaluation method for the uniformity of oil and gas fracturing, characterized in that, it includes the following steps: Obtain four groups of potential difference data collected by the first parallel survey line, the second parallel survey line, the first vertical survey line, and the second vertical survey line respectively; the first parallel survey line, the second parallel survey line, the first vertical survey line, and the second vertical survey line are all arranged on the ground above the fracturing fluid affected body, the first parallel survey line and the second parallel survey line are arranged in parallel, the first vertical survey line and the second vertical survey line are both perpendicular to the first parallel survey line, and the first parallel survey line and the second parallel survey line are both arranged in parallel along the horizontal well section of the wellbore; Determine the planar affected range of the fracturing fluid affected body parallel to the ground according to the four groups of potential difference data, and the planar affected range includes at least a horizontal affected surface and a vertical affected surface perpendicular to the extension direction of the horizontal affected surface; Select N first ranging points at the edge of the vertical affected surface on one side of the wellbore, and calculate the first affected distance values of the N first ranging points to the wellbore; Select N second ranging points at the edge of the vertical affected surface on the other side of the wellbore, and calculate the second affected distance values of the N second ranging points to the wellbore; Generate a first affected characteristic curve according to the multiple first affected distance values; Generate a second affected characteristic curve according to the multiple second affected distance values; Obtain the vertical fracturing uniformity evaluation result according to the first affected characteristic curve and the second affected characteristic curve; Obtain the horizontal fracturing uniformity evaluation result according to the horizontal affected surface.

2. The evaluation method for the uniformity of oil and gas fracturing according to claim 1, characterized in that, the step of obtaining the vertical fracturing uniformity evaluation result according to the first affected characteristic curve and the second affected characteristic curve includes the following steps: Determine the first sample fluctuation parameter of the first affected characteristic curve, and the first sample fluctuation parameter characterizes the dispersion degree of the first affected characteristic curve; Determine the second sample fluctuation parameter of the second affected characteristic curve, and the second sample fluctuation parameter characterizes the dispersion degree of the second affected characteristic curve; Obtain the vertical fracturing uniformity evaluation result according to the first sample fluctuation parameter and the second sample fluctuation parameter.

3. The evaluation method for the uniformity of oil and gas fracturing according to claim 1, characterized in that, the step of obtaining the horizontal fracturing uniformity evaluation result according to the horizontal affected surface includes the following steps: Select N third ranging points at the edge of the horizontal affected surface on one side of the perpendicular bisector of the wellbore, and calculate the third affected distance values of the N third ranging points to the wellbore; Select N fourth ranging points at the edge of the horizontal affected surface on the other side of the perpendicular bisector, and calculate the fourth affected distance values of the N fourth ranging points to the wellbore; Generate a third affected characteristic curve according to the multiple third affected distance values; Generate a fourth affected characteristic curve according to the multiple fourth affected distance values; Obtain the horizontal fracturing uniformity evaluation result according to the third affected characteristic curve and the fourth affected characteristic curve.

4. The method for evaluating the uniformity of oil and gas fracturing according to claim 3, characterized in that, obtaining the horizontal fracturing uniformity evaluation result according to the third wave and characteristic curve and the fourth wave and characteristic curve includes the following steps: Determine the third sample fluctuation parameter of the third wave and characteristic curve, and the third sample fluctuation parameter characterizes the dispersion degree of the third wave and characteristic curve; Determine the fourth sample fluctuation parameter of the fourth wave and characteristic curve, and the fourth sample fluctuation parameter characterizes the dispersion degree of the fourth wave and characteristic curve; Obtain the horizontal fracturing uniformity evaluation result according to the third sample fluctuation parameter and the fourth sample fluctuation parameter.

5. The method for evaluating the uniformity of oil and gas fracturing according to claim 2, characterized in that, the first sample fluctuation parameter includes mean value, variance, and range.

6. The method for evaluating the uniformity of oil and gas fracturing according to claim 1, characterized in that, the four groups of potential difference data are obtained by the following steps: Lay the first parallel survey line, the second parallel survey line, the first vertical survey line, and the second vertical survey line on the ground above the fracturing fluid affected body. Among them, the first parallel survey line and the second parallel survey line are arranged in parallel, the first vertical survey line and the second vertical survey line are both perpendicular to the first parallel survey line, and the first parallel survey line and the second parallel survey line are both arranged in parallel along the horizontal well section of the wellbore; Output a test electrical signal to the wellbore and inject fracturing fluid into the wellbore to respectively obtain the four groups of potential difference data collected by the first parallel survey line, the second parallel survey line, the first vertical survey line, and the second vertical survey line.

7. The method for evaluating the uniformity of oil and gas fracturing according to claim 1, characterized in that, determining the planar affected range of the fracturing fluid affected body parallel to the ground according to the four groups of potential difference data includes the following steps: Subtract each of the potential difference data collected by the first parallel survey line, the second parallel survey line, the first vertical survey line, and the second vertical survey line from the original background field data one by one to obtain four groups of optimized potential data. The original background field data is measured by the first parallel survey line, the second parallel survey line, the first vertical survey line, and the second vertical survey line when the fracturing fluid affected body has not been fractured in the wellbore; Determine the planar affected range of the fracturing fluid affected body parallel to the ground according to the four groups of optimized potential data.

8. An apparatus for evaluating the uniformity of oil and gas fracturing, characterized in that, comprising: A cross-shaped monitoring structure arranged on the ground above the fracturing fluid affected body. The cross-shaped monitoring structure at least includes a first parallel survey line and a second parallel survey line arranged in parallel with each other, and a first vertical survey line and a second vertical survey line both perpendicular to the first parallel survey line. The first parallel survey line and the second parallel survey line are both arranged in parallel along the horizontal well section of the wellbore; A signal transmitting system for outputting a test electrical signal to the wellbore; A signal receiving system for receiving four groups of potential difference data collected by the first parallel survey line, the second parallel survey line, the first vertical survey line, and the second vertical survey line; A data processing system for executing the method for evaluating the uniformity of oil and gas fracturing according to any one of claims 1 to 7.

9. A computer-readable storage medium storing computer-executable instructions, characterized in that, the computer-executable instructions are used to execute the method for evaluating the uniformity of oil and gas fracturing according to any one of claims 1 to 7.

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