Oil well productivity calculation model establishment method, device and equipment and productivity determination method

Abstract

The application relates to the technical field of oil exploration, in particular to an oil well productivity calculation model establishment method, device and equipment, a computer readable storage medium and a productivity determination method. The oil well productivity calculation model establishment method comprises the following steps: obtaining oil well data; generating an elliptical oil well area on a first auxiliary plane according to the oil well data; generating an elliptical oil supply area on the first auxiliary plane according to the oil well data; determining the focal point coordinates of the elliptical oil well area and the elliptical oil supply area; transforming the elliptical oil well area and the elliptical oil supply area into a circular oil well area and a circular oil supply area; determining the radius of the circular oil well area; determining the radius of the circular oil supply area; obtaining formation oil data; and establishing a productivity calculation model according to the formation oil data, the radius of the circular oil well area and the radius of the circular oil supply area. Through the above method, the oil well productivity calculation model can be established, so that the productivity of the oil well can be determined more accurately.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of oil exploration, and particularly relates to an oil well productivity calculation model establishment method, device and equipment, a computer readable storage medium and a productivity determination method. BACKGROUND

[0002] Since most of the oil resources are in low-to-medium permeability reservoirs, the porosity is low and the connectivity is poor, and it is difficult to obtain good development effect by using conventional horizontal wells. Therefore, multi-branch fishbone stinger wells are usually used to improve the productivity of oil wells.

[0003] However, the multi-branch fishbone stinger well structure is complex, and the productivity of the multi-branch fishbone stinger well cannot be accurately judged by the technical personnel in the early stage. SUMMARY

[0004] In view of the above problems, the present application provides an oil well productivity calculation model establishment method, device and equipment, a computer readable storage medium and a productivity determination method, which can establish an oil well productivity calculation model, so as to more accurately determine the productivity of the oil well.

[0005] According to an aspect of the present application, a method for establishing an oil well productivity calculation model is provided. The oil well comprises a main wellbore and a plurality of branch wellbores connected to the main wellbore. The plurality of branch wellbores have equal lengths, and the angles between each branch wellbore and the main wellbore are equal. The branch wellbores comprise at least one intermediate branch wellbore, and the end of the intermediate branch wellbore is located on the median line of the main wellbore. The method comprises: obtaining oil well data, wherein the oil well data comprises the length of the main wellbore, the length of the branch wellbore, and the angle between the branch wellbore and the main wellbore; generating an elliptical oil well area on a first auxiliary plane according to the oil well data, wherein the elliptical oil well area is an elliptical area determined by the end of the intermediate branch wellbore and the two ends of the main wellbore, and the elliptical oil well area has a first major axis and a first minor axis; generating an elliptical oil supply area on the first auxiliary plane according to the oil well data, wherein the elliptical oil supply area is an elliptical area located around the elliptical oil well area and used for supplying oil to the elliptical oil well area, the elliptical oil supply area is confocal with the elliptical oil well area, and the elliptical oil supply area has a second major axis and a second minor axis; determining the focal point coordinates of the elliptical oil well area and the elliptical oil supply area according to the length of the first major axis and the length of the first minor axis or according to the length of the second major axis and the length of the second minor axis, with the center point of the elliptical oil well area as the coordinate origin, the first major axis as the x-axis, and the first minor axis as the y-axis; transforming the elliptical oil well area and the elliptical oil supply area on the first auxiliary plane into a circular oil well area and a circular oil supply area on a second auxiliary plane; determining the radius of the circular oil well area according to the focal point coordinates, the length of the first major axis, and the length of the first minor axis; determining the radius of the circular oil supply area according to the focal point coordinates, the length of the second major axis, and the length of the second minor axis; obtaining formation oil data; and establishing a productivity calculation model according to the formation oil data, the radius of the circular oil well area, and the radius of the circular oil supply area.

[0006] In the method for establishing an oil well productivity calculation model provided by the present application, the oil well is regarded as an elliptical straight well, and the flow of oil and gas from the elliptical oil supply area to the elliptical oil well area is external seepage. The elliptical oil well area and the elliptical oil supply area are transformed into a circular oil well area and a circular oil supply area, so that the productivity of the circular oil supply area to the circular oil well area can be calculated, and thus the productivity calculation model of the external seepage of oil and gas from the elliptical oil supply area to the elliptical oil well area can be established. In subsequent practical applications, by inputting the oil well data and the formation oil data of the actual production well into the oil well productivity calculation model, the productivity of the seepage of oil and gas from the oil supply area to the oil well area can be obtained more accurately.

[0007] In an alternative way, the well data further comprises a radius of the main wellbore; the productivity calculation model is established according to the formation oil data, the radius of the circular wellbore area and the radius of the circular oil supply area, comprising: a first productivity calculation model of radial seepage from the elliptical oil supply area to the elliptical wellbore area is established according to the formation oil data, the radius of the circular wellbore area and the radius of the circular oil supply area; a second productivity calculation model of radial seepage around the main wellbore is determined according to the formation oil data, the radius of the circular wellbore area and the length and radius of the main wellbore; and the productivity calculation model is established according to the first productivity calculation model and the second productivity calculation model. By establishing the second productivity calculation model of radial seepage around the main wellbore and summing the second productivity calculation model with the first productivity calculation model, the productivity calculation model is established, so that in the later application, the well data and the formation oil data are input into the productivity calculation model, and the sum of the productivity of the radial seepage from the elliptical oil supply area to the elliptical wellbore area and the productivity of the radial seepage around the main wellbore can be determined more accurately.

[0008] In an alternative way, the distance between adjacent branch wellbores is equal, and the well data further comprises a spacing distance between the ends of adjacent branch wellbores, a number and a radius of the branch wellbores; the productivity calculation model is established according to the first productivity calculation model and the second productivity calculation model, comprising: a radial oil supply radius around each branch wellbore is determined according to the spacing distance; a third productivity calculation model of radial seepage around the branch wellbores is determined according to the formation oil data, the radial oil supply radius around the branch wellbores and the length, number and radius of the branch wellbores; and the productivity calculation model is established according to the first productivity calculation model, the second productivity calculation model and the third productivity calculation model. By establishing the third productivity calculation model of radial seepage around the branch wellbores and summing the third productivity calculation model with the first productivity calculation model and the second productivity calculation model, the productivity calculation model is established, so that in the later application, the well data and the formation oil data are input into the productivity calculation model, and the sum of the productivity of the radial seepage from the elliptical oil supply area to the elliptical wellbore area, the productivity of the radial seepage around the main wellbore and the productivity of the radial seepage around the branch wellbores can be determined more accurately.

[0009] In an alternative manner, the establishment of the productivity calculation model according to the first productivity calculation model, the second productivity calculation model and the third productivity calculation model comprises: obtaining injection data of the biological nanoparticles under the condition of injecting the biological nanoparticles into the oil well; determining a first average dimensionless permeability from the center of the main wellbore to the injection front of the biological nanoparticles in the main wellbore according to the injection data of the biological nanoparticles, formation oil data and the radius of the main wellbore; determining a second average dimensionless permeability from the center of the branch wellbore to the injection front of the biological nanoparticles in the branch wellbore according to the injection data of the biological nanoparticles, the formation oil data and the radius of the branch wellbore; determining the main wellbore productivity increase coefficient and the branch wellbore productivity increase coefficient after the injection of the biological nanoparticles according to the first average dimensionless permeability, the second average dimensionless permeability, the radius of the circular oil well area, the radial oil supply radius around the branch wellbore, the radius of the main wellbore and the radius of the branch wellbore; determining the second productivity calculation model after the stimulation according to the second productivity calculation model and the main wellbore productivity increase coefficient; determining the third productivity calculation model after the stimulation according to the third productivity calculation model and the branch wellbore productivity increase coefficient; and determining the productivity calculation model according to the first productivity calculation model, the second productivity calculation model after the stimulation and the third productivity calculation model after the stimulation. Through the above scheme, the establishment of the productivity calculation model of the oil well is realized under the condition of injecting the biological nanoparticles into the oil well, and thus the productivity of the oil well with the injection of the biological nanoparticles can be estimated and calculated in actual application.

[0010] In an alternative manner, the establishment of the productivity calculation model according to the first productivity calculation model, the second productivity calculation model and the third productivity calculation model comprises: obtaining injection data of the biological nanoparticles under the condition of injecting the biological nanoparticles into the oil well; determining a first average dimensionless permeability from the center of the main wellbore to the injection front of the biological nanoparticles in the main wellbore according to the injection data of the biological nanoparticles, formation oil data and the radius of the main wellbore; determining a second average dimensionless permeability from the center of the branch wellbore to the injection front of the biological nanoparticles in the branch wellbore according to the injection data of the biological nanoparticles, the formation oil data and the radius of the branch wellbore; determining the main wellbore productivity increase coefficient and the branch wellbore productivity increase coefficient after the injection of the biological nanoparticles according to the first average dimensionless permeability, the second average dimensionless permeability, the radius of the circular oil well area, the radial oil supply radius around the branch wellbore, the radius of the main wellbore and the radius of the branch wellbore; determining the second productivity calculation model after the stimulation according to the second productivity calculation model and the main wellbore productivity increase coefficient; determining the third productivity calculation model after the stimulation according to the third productivity calculation model and the branch wellbore productivity increase coefficient; and determining the productivity calculation model according to the first productivity calculation model, the second productivity calculation model after the stimulation and the third productivity calculation model after the stimulation. Through the above scheme, the establishment of the productivity calculation model of the oil well is realized under the condition of injecting the biological nanoparticles into the oil well, and thus the productivity of the oil well with the injection of the biological nanoparticles can be estimated and calculated in actual application.

[0011] In an alternative manner, the method further comprises: judging whether the length of the main wellbore is greater than or equal to the length of the branch wellbore; if yes, optimizing the productivity calculation model by using the oil well data, the first long axis length, the first short axis length, the second long axis length and the second short axis length to obtain a final productivity calculation model; if no, determining a corresponding relationship between the friction pressure drop of the oil well and the length of the branch wellbore based on the friction pressure drop formula; and determining the final productivity calculation model according to the corresponding relationship and the productivity calculation model. Through the above scheme, the productivity calculation model is optimized in the case that the length of the main wellbore is greater than or equal to the length of the branch wellbore, so as to reduce the calculation amount when the oil well productivity calculation model is applied subsequently and improve the calculation efficiency. Since the longer the length of the branch wellbore is, the more serious the friction pressure drop is, the accuracy of the calculation result of the productivity calculation model is prone to decrease. Therefore, the productivity calculation model is corrected and optimized based on the friction pressure drop formula in the case that the length of the main wellbore is less than the length of the branch wellbore, so that the calculation result of the final productivity calculation model is more accurate and reliable.

[0012] According to another aspect of the present application, a method for determining oil well productivity is provided, comprising: obtaining oil well data and formation oil data; inputting the oil well data and the formation oil data into any of the above productivity calculation models to determine the productivity of the oil well.

[0013] In the method for determining oil well productivity provided by the present application, the oil well data in actual production and the formation oil data obtained by measurement or test detection are input into the established productivity calculation model, so that the productivity of the oil well can be determined more accurately, and a good theoretical basis is provided for subsequent production operations.

[0014] According to another aspect of the present application, there is provided an oil well productivity calculation model establishing apparatus, comprising: a first obtaining unit configured to obtain oil well data, the oil well data comprising a length of a main wellbore, a length of a branch wellbore, and an included angle between the branch wellbore and the main wellbore; a first generating unit configured to generate an elliptical oil well region on a first auxiliary plane according to the oil well data, the elliptical oil well region being an elliptical region generated by one end of the main wellbore and an end of the branch wellbore closest to the one end of the main wellbore, the elliptical oil well region enclosing the main wellbore and the branch wellbore, and the elliptical oil well region having a first major axis and a first minor axis; a second generating unit configured to generate an elliptical oil supply region on the first auxiliary plane according to the oil well data, the elliptical oil supply region being an elliptical region located around the elliptical oil well region and used for supplying oil to the elliptical oil well region, the elliptical oil supply region being confocal with the elliptical oil well region, and the elliptical oil supply region having a second major axis and a second minor axis; a first determining unit configured to determine coordinates of foci of the elliptical oil well region and the elliptical oil supply region according to the length of the first major axis and the length of the first minor axis or according to the length of the second major axis and the length of the second minor axis, with a center point of the elliptical oil well region as a coordinate origin, the first major axis as an x-axis, and the first minor axis as a y-axis; a transforming unit configured to transform the elliptical oil well region and the elliptical oil supply region on the first auxiliary plane into a circular oil well region and a circular oil supply region on a second auxiliary plane; a second determining unit configured to determine a radius of the circular oil well region according to the coordinates of the foci, the length of the first major axis, and the length of the first minor axis; a third determining unit configured to determine a radius of the circular oil supply region according to the coordinates of the foci, the length of the second major axis, and the length of the second minor axis; a second obtaining unit configured to obtain formation oil data; and an establishing unit configured to establish a productivity calculation model according to the formation oil data, the radius of the circular oil well region, and the radius of the circular oil supply region.

[0015] According to another aspect of the present application, there is provided an oil well productivity calculation model establishing apparatus, comprising: a processor, a memory, a communication interface, and a communication bus, the processor, the memory, and the communication interface being in communication with each other through the communication bus; the memory being configured to store at least one executable instruction, the executable instruction causing the processor to perform operations of the oil well productivity calculation model establishing method of any one of the above.

[0016] According to another aspect of the present application, there is provided a computer readable storage medium, the storage medium storing at least one executable instruction, the executable instruction causing an oil well productivity determination apparatus to perform operations of the oil well productivity calculation model establishing method of any one of the above when the executable instruction is run on the oil well productivity determination apparatus.

[0017] The above description is only a summary of the technical solutions of the present application. In order to make the technical means of the present application more clearly understood and implemented according to the content of the specification, and in order to make the above and other purposes, characteristics and advantages of the present application more obvious and easy to understand, the following specific embodiments of the present application are described. BRIEF DESCRIPTION OF DRAWINGS

[0018] Various other advantages and benefits will become apparent to those of ordinary skill in the art upon reading the following detailed description of the preferred embodiments. The accompanying drawings are included to provide a description of the preferred embodiments and are not meant to limit the present application. Moreover, the same reference numerals in the attached drawings indicate the same or similar components. In the drawings:

[0019] Figure 1 Flow chart of the method for establishing the oil well productivity calculation model provided in the embodiments of the present application;

[0020] Figure 2 Structural schematic diagram of the oil well provided in the embodiments of the present application;

[0021] Figure 3 Structural schematic diagram of the oil well, the elliptical oil well area and the elliptical oil supply area provided in the embodiments of the present application;

[0022] Figure 4 For Figure 1 Sub-step flow chart of step 190 in the method;

[0023] Figure 5 For Figure 4 Sub-step flow chart of step 193 in the method;

[0024] Figure 6 For Figure 5 Sub-step flow chart of step 1933 in the method;

[0025] Figure 7 For Figure 6 Sub-step flow chart of step 19337 in the method;

[0026] Figure 8 Further step flow chart of the method for establishing the oil well productivity calculation model provided in the embodiments of the present application;

[0027] Figure 9 Flow chart of the method for determining the oil well productivity provided in the embodiments of the present application;

[0028] Figure 10 Structural schematic diagram of the device for establishing the oil well productivity calculation model provided in the embodiments of the present application;

[0029] Figure 11 Structural schematic diagram of the equipment for establishing the oil well productivity calculation model provided in the embodiments of the present application. DETAILED DESCRIPTION

[0030] Exemplary embodiments of the present application will be described in greater detail below with reference to the accompanying drawings. While exemplary embodiments of the present application are shown in the drawings, it is understood that the present application can be embodied in various forms and should not be limited by the embodiments set forth herein.

[0031] China is rich in oil resources, but most of them are in low-permeability reservoirs. It is difficult to obtain high productivity by using conventional horizontal wells to develop low-permeability reservoirs because the low-permeability reservoirs have low porosity and poor connectivity. The use of fractured horizontal wells can achieve increased production, but as the reservoir pressure decreases over time, the proppant is easily embedded in the rock, causing the fracture to close and the conductivity to decrease, resulting in rapid decline in productivity. Moreover, due to the presence of water in the lower part of some gas reservoirs, the fractured cracks may connect to the water, causing external water to enter the reservoir and affecting oil well production. The use of hydraulic rock breaking to create a multi-branch fishbone stinger well in the reservoir can not only ensure productivity, but also avoid the above problems.

[0032] However, due to the complex structure of the multi-branch fishbone stinger well, the technical personnel cannot accurately judge the productivity of the well in the early stage.

[0033] Therefore, the present application provides an oil well productivity calculation model establishment method. By processing the oil well data and the formation oil data, an oil well productivity calculation model is established. In actual application, the oil well data and the formation oil data of the actual production well are input into the oil well productivity calculation model, and the productivity of the oil and gas seepage from the oil supply area to the oil well area can be obtained more accurately.

[0034] For details, please refer to Figure 1 , which shows the flow of the oil well productivity calculation model establishment method provided by the embodiments of the present application. The method is executed by an oil well productivity calculation model establishment device. The oil well productivity calculation model establishment device includes a computer, a server, etc. Please refer to Figure 2 , which shows the structure of the oil well. As shown in the figure, the oil well 10 includes a main wellbore 11 and a plurality of branch wellbores 12 connected to the main wellbore 11. The main wellbore 11 and the plurality of branch wellbores 12 together form a multi-branch fishbone stinger well. The length of the main wellbore is L1, the lengths L2 of the plurality of branch wellbores 12 are equal, and the included angles a between the branch wellbores 12 and the main wellbore 11 are equal. The branch wellbores 12 include at least one intermediate branch wellbore 121, and the end of the intermediate branch wellbore 121 is located on the perpendicular bisector of the main wellbore 11, as shown in Figure 1 , the method includes the following steps:

[0035] Step 110: Obtain oil well data, including the length of the main wellbore, the length of the branch wellbore, and the included angle between the branch wellbore and the main wellbore.

[0036] For ease of explanation in subsequent calculation steps, in this step, the length of the main wellbore is represented by L1, the length of the branch wellbore by L2, and the angle between the branch wellbore and the main wellbore by α. It should be noted that oil well data can be obtained by inputting actual oil well production parameters into the oil well productivity calculation model building device, or by directly creating a virtual oil well and generating oil well data on the oil well productivity calculation model building device.

[0037] Step 120: Based on the oil well data, generate an elliptical oil well region on the first auxiliary plane. The elliptical oil well region is an elliptical region defined by the end of the intermediate branch wellbore and the two ends of the main wellbore. The elliptical oil well region has a first major axis and a first minor axis.

[0038] Please see Figure 3 The figure shows that Figure 2 The diagram shows an elliptical well region 20 generated by the well. In this step, the elliptical well region 20 is generated through both ends of the main wellbore 11 and the end of the middle branch wellbore 121 in the upper right corner. The elliptical well region 20 has a first major axis 21 and a first minor axis 22. The length of the first major axis 21 is 2a1, i.e., a1 = L1 / 2, and the length of the first minor axis 22 is 2b1, b1 = L1sinα.

[0039] Step 130: Based on the oil well data, generate an elliptical oil supply area on the first auxiliary plane. The elliptical oil supply area is an elliptical area located around the elliptical oil well area and used to supply oil to the elliptical oil well area. The elliptical oil supply area is cofocal with the elliptical oil well area and has a second major axis and a second minor axis.

[0040] In this step, the elliptical oil supply area can be estimated and determined based on the distribution of oil fields and well networks, combined with logging data and actual production experience. Specifically, the shape and size of the elliptical oil supply area corresponding to the distribution of different oil fields and well networks, as well as different logging data, can be pre-set on the oil well productivity calculation model building equipment. For example... Figure 3 As shown, the elliptical oil supply area 30 has a second major axis 31 and a second minor axis 32, the length of the second major axis 31 is set to 2a2, and the length of the second minor axis 32 is set to 2b2.

[0041] Step 140: Using the center point of the elliptical oil well region as the origin of the coordinate system, the first major axis as the x-axis, and the first minor axis as the y-axis, determine the focal coordinates of the elliptical oil well region and the elliptical oil supply region based on the lengths of the first major axis and the first minor axis, or based on the lengths of the second major axis and the second minor axis.

[0042] like Figure 3As shown in the middle of the figure, in this step, the focal point coordinates of the elliptical oil well region and the elliptical oil supply region are set as (±C, 0), and then:

[0043]

[0044]

[0045] From formula (1) and formula (2), we have:

[0046]

[0047] Step 150: Transform the elliptical oil well region and the elliptical oil supply region on the first auxiliary plane into a circular oil well region and a circular oil supply region on the second auxiliary plane.

[0048] In this step, the first auxiliary plane is represented by Z, and the second auxiliary plane is represented by W. According to the Joukowski transformation, the ellipse on the x, y coordinate system on the first auxiliary plane Z is transformed into a circle on the R, θ coordinate system on the second auxiliary plane W, and then:

[0049]

[0050] where Z = x + iy, W = Re iθ = Rcosθ + iRsinθ, and substituting formula (4), we have:

[0051]

[0052] From formula (5), the following corresponding relationship can be obtained:

[0053]

[0054]

[0055] From sin 2 θ + cos 2 θ = 1, we have:

[0056]

[0057] Step 160: Determine the radius of the circular oil well region according to the focal point coordinates, the first major axis length, and the first minor axis length.

[0058] In this step, after the elliptical oil well region on the first auxiliary plane Z is transformed into a circular oil well region on the second auxiliary plane W according to the Joukowski transformation, the radius R w of the circular oil well region is:

[0059]

[0060] Step 170: determining the radius of the circular oil supply region according to the focal point coordinates, the second long axis length and the second short axis length.

[0061] In this step, after the elliptical oil supply region on the first auxiliary plane Z is transformed into a circular oil supply region on the second auxiliary plane W according to the Joukowski transformation, the radius R' of the circular oil supply region is:

[0062]

[0063] Step 180: obtaining formation oil data.

[0064] The formation oil data includes reservoir permeability, oil layer thickness, oil layer supply pressure, bottom hole pressure of the main wellbore and the branch wellbore, and formation oil viscosity. The reservoir permeability can be obtained by logging or testing, the oil layer thickness can be obtained by drilling and logging, the oil layer supply pressure can be obtained according to the reservoir condition combined with experience, the bottom hole pressures of the main wellbore and the branch wellbore are the same, the bottom hole pressure can be directly read by a downhole pressure gauge, and the formation oil viscosity can be obtained by laboratory analysis.

[0065] Step 190: establishing a productivity calculation model according to the formation oil data, the radius of the circular oil well region and the radius of the circular oil supply region.

[0066] In the initial stage of well opening, the oil supply region around the oil well is in the shape of an ellipse, and as the swept area increases, the oil supply region gradually changes from an ellipse to a circle. In steps 120 and 130, the oil well is regarded as an elliptical straight well, and the flow of oil and gas from the elliptical oil supply region to the elliptical oil well region is external seepage. In step 150, the elliptical oil well region and the elliptical oil supply region are transformed into a circular oil well region and a circular oil supply region, so that the productivity of the flow of oil and gas from the circular oil supply region to the circular oil well region can be calculated, and thus a productivity calculation model of the external seepage of the flow of oil and gas from the elliptical oil supply region to the elliptical oil well region can be established. Based on this, assuming that the reservoir is homogeneous, equal in thickness and has a constant pressure supply boundary, the seepage in the formation is one-way stable seepage, and the external seepage productivity Q1 of the flow of oil and gas from the elliptical oil supply region to the elliptical oil well region is:

[0067]

[0068] Formula (11) is the productivity calculation model, wherein K is the reservoir permeability, h is the oil layer thickness, P e is the oil layer supply pressure, P wf is the bottom hole pressure of the main wellbore and the branch wellbore, R' is the radius of the circular oil supply region, R w is the radius of the circular oil well region, and μ0 is the formation oil viscosity.

[0069] The oil well productivity calculation model provided in the method is established by regarding the oil well as an elliptical straight well, and the flow of oil and gas from the elliptical oil supply area to the elliptical oil well area is external seepage. The elliptical oil well area and the elliptical oil supply area are transformed into a circular oil well area and a circular oil supply area, so that the productivity of the circular oil supply area to the circular oil well area can be calculated, and the productivity calculation model of the external seepage of the oil and gas from the elliptical oil supply area to the elliptical oil well area can be established. Therefore, in subsequent actual application, by inputting the oil well data and the formation oil data of the actual production well into the oil well productivity calculation model, the productivity of the oil and gas seepage from the oil supply area to the oil well area can be obtained more accurately.

[0070] Referring to Figure 4 , the sub-step flow of step 190 in Figure 1 is shown in the figure. As shown in the figure, in some embodiments, the oil well data further includes the radius of the main wellbore, that is, the radius of the internal flow passage of the main wellbore. Step 190 includes:

[0071] Step 191: establishing a first productivity calculation model of the seepage from the elliptical oil supply area to the elliptical oil well area according to the formation oil data, the radius of the circular oil well area and the radius of the circular oil supply area.

[0072] In this step, the first productivity calculation model is formula (11) described above.

[0073] Step 192: determining a second productivity calculation model of the radial seepage around the main wellbore according to the formation oil data, the radius of the circular oil well area, and the length and radius of the main wellbore.

[0074] Specifically, in this step, the radial seepage around the main wellbore is regarded as the seepage from the circular oil well area to the inside of the main wellbore, and the second productivity Q2 of the radial seepage around the main wellbore is:

[0075]

[0076] Formula (12) is the second productivity calculation model, wherein L1 represents the length of the main wellbore, and r1 represents the radius of the main wellbore.

[0077] Step 193: establishing a productivity calculation model according to the first productivity calculation model and the second productivity calculation model.

[0078] In this step, the sum of the productivity of the seepage from the elliptical oil supply area to the elliptical oil well area and the radial seepage around the main wellbore Q is obtained by summing formula (11) and formula (12). 12 is:

[0079]

[0080] The formula (13) is a new production capacity calculation model.

[0081] The second production capacity calculation model of the radial seepage around the main wellbore is established, and the second production capacity calculation model is summed with the first production capacity calculation model to establish the production capacity calculation model. In the later application, the oil well data and the formation oil data are input into the production capacity calculation model, so that the sum of the production capacity of the seepage from the elliptical oil supply area to the elliptical well area and the radial seepage around the main wellbore can be accurately determined.

[0082] Further, please refer to Figure 2 and Figure 3 In some embodiments, the distance between adjacent branch wellbores 12 is equal, and the oil well data further includes the interval distance m between the ends of adjacent branch wellbores 12, the number n of branch wellbores 12, and the radius r2 of the branch wellbores 12, which is the radius of the internal flow passage of the branch wellbores 12. Please refer to Figure 5 , which shows the sub-step flow of step 193 in Figure 4 . As shown in Figure 5 , step 193 includes the following steps:

[0083] Step 1931: Determine the radial oil supply radius around each branch wellbore according to the interval distance.

[0084] In this step, the radial oil supply radius around each branch wellbore is set as where m is the interval distance between the ends of adjacent branch wellbores, and h is the thickness of the oil layer.

[0085] Step 1932: Determine the third production capacity calculation model of the radial seepage around the branch wellbore according to the formation oil data, the radial oil supply radius around the branch wellbore, and the length, number, and radius of the branch wellbore.

[0086] In this step, the third production capacity Q3 of the radial seepage around the branch wellbore is:

[0087]

[0088] The formula (14) is the third production capacity calculation model.

[0089] Step 1933: Establish the production capacity calculation model according to the first production capacity calculation model, the second production capacity calculation model, and the third production capacity calculation model.

[0090] In this step, the first production capacity calculation model, the second production capacity calculation model, and the third production capacity calculation model are summed to determine the production capacity calculation model Q 123 , Q 123 is:

[0091]

[0092] Equation (15) is the deliverability calculation model determined in step 1934.

[0093] By establishing the third deliverability calculation model of radial seepage around the branch wellbore and summing the third deliverability calculation model with the first deliverability calculation model and the second deliverability calculation model, the deliverability calculation model is established, so that in the later application, the oil well data and the formation oil data are input into the deliverability calculation model, and the sum of the deliverability of the seepage from the elliptical oil supply area to the elliptical oil well area, the deliverability of the radial seepage around the main wellbore and the deliverability of the radial seepage around the branch wellbore can be determined more accurately.

[0094] Further, please refer to Figure 6 , which shows the sub-step flow of step 1933 in Figure 5 . As shown in the figure, in some embodiments, step 1933 includes the following steps:

[0095] Step 19331: Obtain injection data of the biological nanoparticles under the condition of injecting the biological nanoparticles into the oil well.

[0096] Nanotechnology is a technology developed in the late 1980s, as a new comprehensive science and technology applied in various fields, mainly studying the motion law and interaction of substance systems with a size of 0.1-100.0 nm. Among them, nanomaterials are also used in oil field plugging, descaling, pressure reduction and injection increase. The key of nanotechnology is to control the surface physical and chemical properties of nanomaterials through surface modification and surface wrapping. In complex formations and extreme environments, by selecting particle types, surface modification, modification or adding chemical stabilizers, the nanomaterial working fluid meets the above conditions to obtain the multifunctionality and adaptability of nanomaterials to achieve the desired effect in the mine.

[0097] Biological nano-solution is a comprehensive application of physical-chemical-biological method to reduce the seepage resistance near the wellbore, use its adsorption and strong hydrophobicity to form a film on the inner surface of the reservoir pore throat, inhibit clay hydration and swelling, reduce fluid seepage resistance, and enhance the porosity and permeability of porous media. After the fishbone well treated by the biological nano-solution, the exposed area and drainage channel of the reservoir can be further increased, and the seepage capacity of the wellbore can be greatly improved, thereby improving the oil well productivity and recovery rate. Therefore, it is necessary to study the deliverability prediction of the fishbone well treated by the biological nanoparticles in low permeability and ultra-low permeability reservoirs.

[0098] In this step, under the condition of injecting the biological nanoparticles into the oil well, based on the oil and gas seepage theory, considering the branch length, branch angle and branch number of any distribution in three-dimensional space, combining the biological nano-solution seepage resistance characterization method, the productivity calculation model of the fishbone-stick well treated by the biological nano-solution is established, which lays a theoretical foundation for the development of oil reservoirs by applying the biological nano-technology and the fishbone-stick well technology.

[0099] Specifically, the injection data of the biological nanoparticles include the concentration of the injected biological nanoparticles, the concentration of the adsorbed biological nanoparticles in the formation, the injection time, the seepage kinetics coefficient and the injection speed of the biological nanoparticles.

[0100] Step 19332: determining the first average dimensionless permeability from the center of the main wellbore to the injection front of the biological nanoparticles in the main wellbore according to the injection data of the biological nanoparticles, the formation oil data and the radius of the main wellbore.

[0101] In this step, the formation oil data further include the oil layer porosity and the oil layer original permeability.

[0102] Step 19333: determining the second average dimensionless permeability from the center of the branch wellbore to the injection front of the biological nanoparticles in the branch wellbore according to the injection data of the biological nanoparticles, the formation oil data and the radius of the branch wellbore.

[0103] In step 19332 and step 19333, the injection front of the biological nanoparticles is the position of the biological nanoparticles after entering the formation from the wellbore wall. It should be noted that there is no sequential relationship between step 19332 and step 19333.

[0104] Since the biological nanoparticles for pressure reduction and injection increase are only distributed in the near wellbore, in order to establish the radial composite model of the main wellbore and the branch wellbore, the concentration distribution and the adsorption amount distribution curve of the biological nanoparticles in the near wellbore after injection are obtained by experiment to evaluate the seepage resistance dynamics of the near wellbore. Since the biological nanoparticles have small particle size and can enter the formation, only internal filtration is considered here, and the influence of the formation of external filter cake is not considered.

[0105] The concentration distribution of the biological nanoparticles satisfies the following seepage kinetics equation:

[0106]

[0107] Wherein, δ is the concentration of the adsorbed biological nanoparticles in the formation, t is the injection time, λ is the seepage kinetics coefficient, and M is the concentration of the injected biological nanoparticles.

[0108] Under the condition of radial flow, formula (16) can be converted to:

[0109]

[0110] wherein q is the injection velocity of the bio-nanoparticles, r is the distance from the injection front of the bio-nanoparticles to the center of the main wellbore or the distance from the injection front of the bio-nanoparticles to the center of the branch wellbore, h is the thickness of the oil reservoir, is the porosity of the oil reservoir.

[0111] The initial conditions and boundary conditions at the main wellbore are as follows:

[0112] r = r1, M = M0, t = 0 (18)

[0113] t > 0, M > 0, δ = 0, r1 < r < R w (19)

[0114] wherein r1 is the radius of the main wellbore, M0 is the concentration of the bio-nanoparticles actually injected, R w is the radius of the circular wellbore region.

[0115] The initial conditions and boundary conditions at the branch wellbore are as follows:

[0116] r = r1, M = M0, t = 0 (20)

[0117] t > 0, M > 0, δ = 0, r2 < r < R a (21)

[0118] After the bio-nanomaterials are injected, the linear relationship between the pressure drop and the amount of injected particles is determined by the following formula:

[0119]

[0120] wherein β is the bio-nano coefficient, which is related to the physical properties, particle size, and concentration of the bio-nanoparticles, and an empirical value can be taken. K0 is the original permeability of the oil reservoir.

[0121] By solving the simultaneous equations (17) to (22), the first average dimensionless permeability from the center of the main wellbore to the injection front of the bio-nanoparticles in the main wellbore and the second average dimensionless permeability from the center of the branch wellbore to the injection front of the bio-nanoparticles in the branch wellbore are expressed as:

[0122]

[0123] wherein represents the first average dimensionless permeability or the second average dimensionless permeability. When is the first average dimensionless permeability, r' is the radius of the main wellbore, R f is the distance from the center of the main wellbore to the injection front of the bio-nanoparticles in the main wellbore. When is the second average dimensionless permeability, r' is the radius of the branch wellbore, and R f is the distance from the center of the branch wellbore to the bio-nanoparticle injection front in the branch wellbore.

[0124] Step 19334: According to the first average dimensionless permeability, the second average dimensionless permeability, the radius of the circular oil well area, the radial oil supply radius around the branch wellbore, the radius of the main wellbore, and the radius of the branch wellbore, the main wellbore productivity increase coefficient and the branch wellbore productivity increase coefficient after injecting bio-nanoparticles are determined.

[0125] In this step, the productivity increase coefficient is the ratio of the seepage resistance after injecting bio-nanoparticles to the seepage resistance before injecting bio-nanoparticles, and the seepage resistance is expressed as:

[0126]

[0127] wherein K represents the reservoir permeability, h represents the oil layer thickness, and μ0 represents the formation oil viscosity. For the seepage resistance of the main wellbore, R x is the radius of the circular oil well area (i.e., the above-mentioned R w ), and r' represents the radius of the main wellbore (i.e., the above-mentioned r1). For the seepage resistance of the branch wellbore, R x is the radial oil supply radius around the branch wellbore (i.e., the above-mentioned R a ), and r' represents the radius of the branch wellbore (i.e., the above-mentioned r2).

[0128] Based on this, under the condition of radial flow, after injecting bio-nanoparticles, the productivity increase coefficient a is expressed as:

[0129]

[0130] wherein when a represents the main wellbore productivity increase coefficient, represents the first average dimensionless permeability, R x represents the radius of the circular oil well area (i.e., the above-mentioned R w ), R f represents the distance from the center of the main wellbore to the bio-nanoparticle injection front in the main wellbore, and r' represents the radius of the main wellbore. When a represents the branch wellbore productivity increase coefficient, represents the second average dimensionless permeability, R x represents the radial oil supply radius around the branch wellbore (i.e., the above-mentioned R a ), R f represents the distance from the center of the branch wellbore to the bio-nanoparticle injection front in the main wellbore, and r' represents the radius of the branch wellbore.

[0131] Step 19335: According to the second productivity calculation model and the main wellbore productivity increase coefficient, a second productivity calculation model after stimulation is determined.

[0132] In this step, after the injection of the biological nanoparticles, the second productivity calculation model in formula (12) is multiplied by the main wellbore productivity increase coefficient in formula (25) to obtain the third productivity calculation model after stimulation as follows:

[0133]

[0134] Step 19336: determining the third productivity calculation model after stimulation according to the third productivity calculation model and the branch wellbore productivity increase coefficient.

[0135] In this step, after the injection of the biological nanoparticles, the third productivity calculation model in formula (14) is multiplied by the main wellbore productivity increase coefficient in formula (25) to obtain the third productivity calculation model after stimulation as follows:

[0136]

[0137] It should be noted that there is no sequential relationship between step 19335 and step 19336.

[0138] Step 19337: determining the productivity calculation model according to the first productivity calculation model, the second productivity calculation model after stimulation and the third productivity calculation model after stimulation.

[0139] In this step, the first productivity calculation model in formula (11), the second productivity calculation model after stimulation in formula (26) and the third productivity calculation model after stimulation in formula (27) are summed to obtain a new productivity calculation model as follows:

[0140]

[0141] Through the above scheme, the establishment of the oil well productivity calculation model is realized under the condition of injecting biological nanoparticles into the oil well, and further in actual application, the productivity of the oil well injected with biological nanoparticles can be estimated and calculated.

[0142] When the branch wellbore is long, the seepage to the main wellbore is shielded, the seepage flow of the main wellbore is reduced, and the seepage interference between the branch wellbores is increased. Based on this, the present application further proposes an embodiment, which specifically refers to Figure 7 , which shows the sub-step process of step 19337 in Figure 6 . As shown in the figure, step 19337 includes the following steps:

[0143] Step 193371: according to the length and interval distance of the branch wellbore, the second productivity calculation model after stimulation is locally corrected for seepage resistance to obtain a corrected second productivity calculation model.

[0144] Specifically, in this step, the local seepage resistance of the main wellbore is corrected by using the length of the branch wellbore and the interval distance between adjacent branch wellbores, and combining with experimental experience, and the productivity of the radial seepage around the main wellbore after correction is:

[0145]

[0146] Formula (29) is a corrected second productivity calculation model, wherein L1 is the length of the main wellbore, L2 is the length of the branch wellbore, and m is the interval distance between the ends of adjacent branch wellbores. According to (L1-L2 / m) in the molecule of formula (29), when L2 / m is larger, the productivity Q2” of the radial seepage around the main wellbore is smaller, and vice versa, the productivity Q2” of the radial seepage around the wellbore is larger.

[0147] Step 193372: determining the productivity calculation model according to the first productivity calculation model, the corrected second productivity calculation model, and the third productivity calculation model after stimulation.

[0148] In this step, the first productivity calculation model of formula (11), the corrected second productivity calculation model of formula (29), and the third productivity calculation model after stimulation of formula (27) are summed to obtain a new productivity calculation model as follows:

[0149]

[0150] When the branch wellbore is long, the seepage of the main wellbore is shielded, the seepage flow is reduced, and the seepage interference between the branch wellbores is increased, so that the productivity calculated by the productivity calculation model is prone to be too large, and after the productivity of the radial seepage around the main wellbore is corrected by the above scheme, the problem can be effectively solved.

[0151] Further, please refer to Figure 8 , which shows the steps after step 193372 in Figure 7 . As shown in the figure, the oil well productivity calculation model establishment method further includes the following steps:

[0152] Step 193373: determining whether the length of the main wellbore is greater than or equal to the length of the branch wellbore.

[0153] If the determination result of step 193373 is yes, the following step is performed:

[0154] Step 193374: using the oil well data, the first long axis length, the first short axis length, the second long axis length, and the second short axis length to optimize the productivity calculation model to obtain a final productivity calculation model.

[0155] In this step, if the length L1 of the main wellbore is greater than or equal to the length L2 of the branch wellbore, the above formula (30) is optimized. Specifically, the above formulas (1)-(3) and formula (30) are solved simultaneously, and formula (30) is optimized with a1=L1 / 2 and b1=L1sinα, to obtain the final productivity calculation model as follows:

[0156]

[0157] where R' represents the radius of the circular oil supply area, L1 represents the length of the main wellbore, L2 represents the length of the branch wellbore, and a represents the included angle between the main wellbore and the branch wellbore.

[0158] If the result of step 193373 is no, the following steps are performed:

[0159] Step 193375: Based on the friction pressure drop formula, the corresponding relationship between the friction pressure drop of the oil well and the length of the branch wellbore is determined.

[0160] Since the longer the length of the branch wellbore, the more serious the friction pressure drop, the accuracy of the calculation result of the productivity calculation model is easily reduced, therefore when the length L1 of the main wellbore is less than the length L2 of the branch wellbore, the corresponding relationship between the friction pressure drop and the length of the branch wellbore is obtained according to the friction pressure drop formula as follows:

[0161]

[0162] where Δp is the friction pressure drop. f is the comprehensive compression coefficient of the formation rock, which can be obtained by experimental detection. p is the density of the bio-nano fluid, which can be obtained by laboratory detection. Q is the productivity. D is the diameter of the branch wellbore.

[0163] Step 193376: According to the corresponding relationship and the productivity calculation model, the final productivity calculation model is determined.

[0164] In this step, formula (32) is added to formula (30), and formulas (1)-(3) and formula (30) are solved simultaneously to obtain the final productivity calculation model as follows:

[0165]

[0166] Through the above scheme, for the case that the length of the main wellbore is greater than or equal to the length of the branch wellbore, the productivity calculation model is optimized to reduce the amount of calculation when the oil well productivity calculation model is applied subsequently and improve the calculation efficiency. Since the longer the length of the branch wellbore is, the more serious the friction pressure drop is, the accuracy of the calculation result of the productivity calculation model is easily reduced. Therefore, for the case that the length of the main wellbore is less than the length of the branch wellbore, the productivity calculation model is modified and optimized based on the friction pressure drop formula, so that the calculation result of the final productivity calculation model is more accurate and reliable.

[0167] According to another aspect of the embodiments of the present application, an oil well productivity determination method is also provided, please refer to Figure 9 , which shows the flow of the oil well productivity determination method. As shown in the figure, the method comprises the following steps:

[0168] Step 210: Obtain oil well data and formation oil data.

[0169] In this step, the oil well data in actual production and the formation oil data obtained by measurement or test detection are input into the oil well productivity determination device (such as a computer, a server, etc.).

[0170] Step 220: Input the oil well data and the formation oil data into the productivity calculation model in any of the above embodiments to determine the productivity of the oil well.

[0171] In the oil well productivity determination method provided by the present application, the oil well data in actual production and the formation oil data obtained by measurement or test detection are input into the established productivity calculation model, so that the productivity of the oil well can be determined more accurately, which provides a good theoretical basis for subsequent production operations.

[0172] According to another aspect of the embodiments of the present application, an oil well productivity calculation model establishment device is also provided, please refer to Figure 10As shown in the figure, the oil well productivity calculation model establishing device 300 comprises a first acquisition unit 310, a first generation unit 320, a second generation unit 330, a first determination unit 340, a transformation unit 350, a second determination unit 360, a third determination unit 370, a second acquisition unit 380 and an establishing unit 390. The first acquisition unit 310 is configured to acquire oil well data, the oil well data comprising the length of the main wellbore, the length of the branch wellbore and the included angle between the branch wellbore and the main wellbore. The first generation unit 320 is configured to generate an elliptical oil well region on a first auxiliary plane according to the oil well data, the elliptical oil well region being an elliptical region determined by the end of the middle branch wellbore and the two ends of the main wellbore, the elliptical oil well region having a first major axis and a first minor axis. The second generation unit 330 is configured to generate an elliptical oil supply region on the first auxiliary plane according to the oil well data, the elliptical oil supply region being an elliptical region located around the elliptical oil well region and used for supplying oil to the elliptical oil well region, the elliptical oil supply region being confocal with the elliptical oil well region, the elliptical oil supply region having a second major axis and a second minor axis. The first determination unit 340 is configured to determine the focal point coordinates of the elliptical oil well region and the elliptical oil supply region with the center point of the elliptical oil well region as the coordinate origin, the first major axis as the x-axis and the first minor axis as the y-axis, according to the first major axis length and the first minor axis length or according to the second major axis length and the second minor axis length. The transformation unit 350 transforms the elliptical oil well region and the elliptical oil supply region on the first auxiliary plane into a circular oil well region and a circular oil supply region on a second auxiliary plane. The second determination unit 360 is configured to determine the radius of the circular oil well region according to the focal point coordinates, the first major axis length and the first minor axis length. The third determination unit 370 is configured to determine the radius of the circular oil supply region according to the focal point coordinates, the second major axis length and the second minor axis length. The second acquisition unit 380 is configured to acquire formation oil data. The establishing unit 390 is configured to establish a productivity calculation model according to the formation oil data, the radius of the circular oil well region and the radius of the circular oil supply region.

[0173] In some embodiments, the oil well data further comprises the radius of the main wellbore, i.e. the radius of the flow passage inside the main wellbore. The establishing unit 390 is further configured to establish a first productivity calculation model of the seepage from the elliptical oil supply region to the elliptical oil well region according to the formation oil data, the radius of the circular oil well region and the radius of the circular oil supply region. The establishing unit 390 is further configured to determine a second productivity calculation model of the radial seepage around the main wellbore according to the formation oil data, the radius of the circular oil well region and the length and radius of the main wellbore. The establishing unit 390 is further configured to establish the productivity calculation model according to the first productivity calculation model and the second productivity calculation model.

[0174] In some embodiments, the distance between adjacent branch wellbores is equal, and the well data further comprises a spacing distance between ends of adjacent branch wellbores, a number of branch wellbores, and a radius of the branch wellbores, i.e., a radius of the flow channel inside the branch wellbores. The establishing unit 390 is further configured to determine a radial oil supply radius around each branch wellbore according to the spacing distance. The establishing unit 390 is further configured to determine a third productivity calculation model of radial seepage around the branch wellbores according to the formation oil data, the radial oil supply radius around the branch wellbores, and the length, number, and radius of the branch wellbores. The establishing unit 390 is further configured to establish the productivity calculation model according to the first productivity calculation model, the second productivity calculation model, and the third productivity calculation model.

[0175] In some embodiments, the establishing unit 390 is further configured to obtain injection data of the bio-nanoparticles under the condition of injecting the bio-nanoparticles into the well. The establishing unit 390 is further configured to determine a first average dimensionless permeability from a center of the main wellbore to a leading edge of the bio-nanoparticle injection in the main wellbore according to the injection data of the bio-nanoparticles, the formation oil data, and the radius of the main wellbore. The establishing unit 390 is further configured to determine a second average dimensionless permeability from a center of the branch wellbore to the leading edge of the bio-nanoparticle injection in the branch wellbore according to the injection data of the bio-nanoparticles, the formation oil data, and the radius of the branch wellbore. The establishing unit 390 is further configured to determine a main wellbore productivity increase coefficient and a branch wellbore productivity increase coefficient after injection of the bio-nanoparticles according to the first average dimensionless permeability, the second average dimensionless permeability, the radius of the circular well area, the radial oil supply radius around the branch wellbores, the radius of the main wellbore, and the radius of the branch wellbores. The establishing unit 390 is further configured to determine a second productivity calculation model after stimulation according to the second productivity calculation model and the main wellbore productivity increase coefficient. The establishing unit 390 is further configured to determine a third productivity calculation model after stimulation according to the third productivity calculation model and the branch wellbore productivity increase coefficient. The establishing unit 390 is further configured to determine the productivity calculation model according to the first productivity calculation model, the second productivity calculation model after stimulation, and the third productivity calculation model after stimulation.

[0176] In some embodiments, the establishing unit 390 is further configured to correct the second productivity calculation model after stimulation for local seepage resistance according to the length of the branch wellbores and the spacing distance, to obtain a corrected second productivity calculation model. The establishing unit 390 is further configured to determine the productivity calculation model according to the first productivity calculation model, the corrected second productivity calculation model, and the third productivity calculation model after stimulation.

[0177] In some embodiments, the establishing unit 390 is further configured to determine whether the length of the main wellbore is greater than or equal to the length of the branch wellbore, and if the determination result is yes, optimize the productivity calculation model by using the oil well data, the first long axis length, the first short axis length, the second long axis length, and the second short axis length to obtain a final productivity calculation model. If the determination result is no, determine a corresponding relationship between the friction pressure drop of the oil well and the length of the branch wellbore based on the friction pressure drop formula, and determine the final productivity calculation model according to the corresponding relationship and the productivity calculation model.

[0178] According to another aspect of the embodiments of the present application, an oil well productivity calculation model establishing device is also provided, and the structure of the oil well productivity calculation model establishing device is shown in Figure 11 . It should be noted that the specific implementation of the oil well productivity calculation model establishing device is not limited in the embodiments of the present application.

[0179] As shown in Figure 11 , the oil well productivity calculation model establishing device can include a processor 402, a communications interface 404, a memory 406, and a communications bus 408.

[0180] The processor 402, the communications interface 404, and the memory 406 can communicate with each other through the communications bus 408. The communications interface 404 is configured to communicate with network elements such as clients or other servers. The processor 402 is configured to execute the program 410, and specifically can execute the related steps in the above-mentioned oil well productivity calculation model establishing method embodiments.

[0181] Specifically, the program 410 can include program codes including computer executable instructions.

[0182] The processor 402 can be a central processing unit CPU, or an application specific integrated circuit ASIC, or one or more integrated circuits configured to implement the embodiments of the present application. The one or more processors of the oil well productivity calculation model establishing device can be the same type of processors, such as one or more CPUs; or can be different types of processors, such as one or more CPUs and one or more ASICs.

[0183] The memory 406 is configured to store the program 410. The memory 406 can include a high-speed RAM memory, and can also include a non-volatile memory such as at least one disk memory.

[0184] The program 410 can be specifically invoked by the processor 402 to make the oil well productivity calculation model establishing device perform the following operations:

[0185] Obtain oil well data, the oil well data including a length of a main wellbore, a length of a branch wellbore, and an included angle between the branch wellbore and the main wellbore;

[0186] Generate an elliptical oil well region on a first auxiliary plane according to the oil well data, the elliptical oil well region being an elliptical region determined by a terminal end of the middle branch wellbore and two ends of the main wellbore, the elliptical oil well region having a first major axis and a first minor axis;

[0187] Generate an elliptical oil supply region on the first auxiliary plane according to the oil well data, the elliptical oil supply region being an elliptical region located around the elliptical oil well region and used for supplying oil to the elliptical oil well region, the elliptical oil supply region being confocal with the elliptical oil well region, the elliptical oil supply region having a second major axis and a second minor axis;

[0188] Determine coordinates of foci of the elliptical oil well region and the elliptical oil supply region according to the length of the first major axis and the length of the first minor axis or according to the length of the second major axis and the length of the second minor axis, with a center point of the elliptical oil well region as a coordinate origin, the first major axis as an x axis, and the first minor axis as a y axis;

[0189] Transform the elliptical oil well region and the elliptical oil supply region on the first auxiliary plane into a circular oil well region and a circular oil supply region on a second auxiliary plane;

[0190] Determine a radius of the circular oil well region according to the coordinates of the foci, the length of the first major axis, and the length of the first minor axis;

[0191] Determine a radius of the circular oil supply region according to the coordinates of the foci, the length of the second major axis, and the length of the second minor axis;

[0192] Obtain formation oil data;

[0193] Establish a productivity calculation model according to the formation oil data, the radius of the circular oil well region, and the radius of the circular oil supply region.

[0194] According to another aspect of the application, a computer readable storage medium is provided, the storage medium storing at least one executable instruction, which, when executed on an oil well productivity calculation model establishing device, causes the oil well productivity calculation model establishing device to perform the oil well productivity calculation model establishing method in any of the method embodiments.

[0195] The algorithms and displays presented herein are not inherently related to any particular computer, virtual system, or other apparatus. Various general purpose systems can be used with programs in accordance with the teachings herein, or it can prove convenient to construct more specialized apparatus to perform the required method steps. The required structure for a variety of these systems will be apparent from the description above. In addition, the present embodiments are not described with reference to any particular programming language. It will be appreciated that a variety of programming languages can be used to implement the teachings of the application as described herein, and any references below to specific languages are provided for disclosure of enablement of the best mode of the application.

[0196] In the description provided herein, numerous specific details are set forth. However, it is understood that embodiments of the application can be practiced without these specific details. In some instances, well-known methods, structures and techniques have not been described in detail in order to not obscure the understanding of this description.

[0197] Similarly, it is to be understood that the mechanical details of the application that have been set forth in the description above of exemplary embodiments of the application are intended to be illustrative only. As such, the scope of the application is not to be construed as being limited to such specific embodiments. Furthermore, while the application has been described in some embodiments with reference to specific apparatus, methods, and examples, the actual scope of the application is not limited to the embodiments. Rather, the scope of the application is defined by the appended claims and equivalents thereof.

[0198] Those of skill in the art would understand that information and signals can be represented using any of a variety of technologies and techniques. For the purposes of this disclosure, the terms "information" and "signals" can be used interchangeably. Those of skill in the art would appreciate that the various illustrative logical blocks, modules, circuits, and algorithm steps described in connection with the embodiments disclosed herein can be implemented as electronic hardware, computer software, or combinations of both. To clearly illustrate this interchangeability of hardware and software, various illustrative components, blocks, modules, circuits, and steps have been described above generally in terms of their functionality, rather than their specific arrangement of hardware or software. Depending upon the implementation chosen, such a functionality can be implemented in a variety of ways, e.g., by using digital logic to perform the functionality, by using one or more processors under the control of software, etc. In an embodiment, the various illustrative logical blocks, modules, and circuits described in connection with the embodiments disclosed herein can be implemented or performed by a machine, such as a general purpose processor, a Digital Signal Processor (DSP), an Application Specific Integrated Circuit (ASIC), a Field Programmable Gate Array (FPGA) or Digital Signal Processing Device (DSPD), located in one or more electronic devices.

[0199] It should be noted that the above-mentioned embodiments illustrate rather than limit the application, and that those skilled in the art will be able to design many alternative embodiments without departing from the scope of the appended claims. In the claims, any reference signs placed between parentheses shall not be construed as limiting the claim. The word 'comprising' does not exclude the presence of elements or steps other than those listed in a claim. The word 'a' or 'an' preceding an element does not exclude the presence of a plurality of such elements. The application can be implemented by means of both hardware and software, and any combination thereof. In a unitary claim, several devices, apparatuses or means can be listed, comprising means for carrying out a certain task. The use of the term'means' in a claim is intended to refer to a combination of devices, apparatuses or means for carrying out a task. The word 'first','second', 'third', etc. do not imply any order. The use of these terms is to be construed as an indication of particular embodiments. Steps in the above-described embodiments, unless otherwise specified, are not to be construed as necessarily limiting the order in which the steps are performed.

Claims

1. A method for establishing an oil well productivity calculation model, characterized in that, The oil well includes a main wellbore and multiple branch wellbores connected to the main wellbore. The multiple branch wellbores are of equal length, have equal angles with the main wellbore, and are equidistant from each other. Each branch wellbore includes at least one intermediate branch wellbore, the end of which is located on the vertical axis of the main wellbore. The method includes: Acquire oil well data, which includes the length of the main wellbore, the radius of the main wellbore, the length of the branch wellbore, the angle between the branch wellbore and the main wellbore, the distance between the ends of adjacent branch wellbores, and the number and radius of the branch wellbores; Based on the oil well data, an elliptical oil well region is generated on the first auxiliary plane. The elliptical oil well region is an elliptical region defined by the end of the intermediate branch wellbore and the two ends of the main wellbore. The elliptical oil well region has a first major axis and a first minor axis. Based on the oil well data, an elliptical oil supply area is generated on the first auxiliary plane. The elliptical oil supply area is an elliptical area located around the elliptical oil well area and used to supply oil to the elliptical oil well area. The elliptical oil supply area is confocal with the elliptical oil well area and has a second major axis and a second minor axis. With the center point of the elliptical oil well region as the origin of the coordinate system, the first major axis as the x-axis, and the first minor axis as the y-axis, the focal coordinates of the elliptical oil well region and the elliptical oil supply region are determined based on the lengths of the first major axis and the first minor axis, or based on the lengths of the second major axis and the second minor axis. The elliptical oil well area and the elliptical oil supply area on the first auxiliary plane are transformed into a circular oil well area and a circular oil supply area on the second auxiliary plane; The radius of the circular oil well region is determined based on the focal coordinates, the length of the first major axis, and the length of the first minor axis. The radius of the circular oil supply area is determined based on the focal coordinates, the length of the second major axis, and the length of the second minor axis. Obtain formation oil data; Based on the formation oil data, the radius of the circular oil well region, and the radius of the circular oil supply region, a first production capacity calculation model is established for the seepage from the elliptical oil supply region to the elliptical oil well region. Based on the formation oil data, the radius of the circular oil well area, and the length and radius of the main wellbore, a second productivity calculation model for radial seepage around the main wellbore is determined. Based on the interval distance, the radial oil supply radius around each branch well is determined; based on the formation oil data, the radial oil supply radius around the branch well, and the length, number, and radius of the branch well, a third production capacity calculation model for radial seepage around the branch well is determined; The capacity calculation model is established based on the first capacity calculation model, the second capacity calculation model, and the third capacity calculation model.

2. The method for establishing an oil well productivity calculation model according to claim 1, characterized in that, The step of establishing the capacity calculation model based on the first capacity calculation model, the second capacity calculation model, and the third capacity calculation model includes: Under the condition of injecting bio-nanoparticles into the oil well, the injection data of the bio-nanoparticles are obtained; Based on the injection data of the bio-nanoparticles, the formation oil data, and the radius of the main wellbore, determine the first average dimensionless permeability from the center of the main wellbore to the injection front of the bio-nanoparticles in the main wellbore; Based on the injection data of the bio-nanoparticles, the formation oil data, and the radius of the branch wellbore, determine the second average dimensionless permeability from the center of the branch wellbore to the injection front of the bio-nanoparticles in the branch wellbore; Based on the first average dimensionless permeability, the second average dimensionless permeability, the radius of the circular oil well area, the radial oil supply radius around the branch wellbore, the radius of the main wellbore, and the radius of the branch wellbore, the production capacity increase coefficient of the main wellbore and the production capacity increase coefficient of the branch wellbore after injecting the bio-nanoparticles are determined. Based on the second production capacity calculation model and the main shaft production capacity increase coefficient, the second production capacity calculation model after the production increase is determined; Based on the aforementioned third production capacity calculation model and the branch wellbore production capacity increase coefficient, the third production capacity calculation model after the production increase is determined. The capacity calculation model is determined based on the first capacity calculation model, the second capacity calculation model after the increase in production, and the third capacity calculation model after the increase in production.

3. The method for establishing an oil well productivity calculation model according to claim 2, characterized in that, The step of determining the capacity calculation model based on the first capacity calculation model, the second capacity calculation model after the capacity increase, and the third capacity calculation model after the capacity increase includes: Based on the length of the branch wellbore and the interval distance, the local seepage resistance is corrected in the second production capacity calculation model after the production increase to obtain the corrected second production capacity calculation model. The capacity calculation model is determined based on the first capacity calculation model, the modified second capacity calculation model, and the increased capacity calculation model.

4. The method for establishing an oil well productivity calculation model according to claim 3, characterized in that, The method further includes: Determine whether the length of the main wellbore is greater than or equal to the length of the branch wellbore; If so, the production capacity calculation model is optimized using the oil well data, the first major axis length, the first minor axis length, the second major axis length, and the second minor axis length to obtain the final production capacity calculation model; If not, then based on the friction pressure drop formula, determine the correspondence between the friction pressure drop of the oil well and the length of the branch wellbore; Based on the correspondence and the capacity calculation model, the final capacity calculation model is determined.

5. A method for determining oil well productivity, characterized in that, include: Acquire oil well data and formation oil data; The oil well data and the formation oil data are input into the production capacity calculation model established according to any one of claims 1-4 to determine the production capacity of the oil well.

6. An apparatus for establishing an oil well productivity calculation model, characterized in that, The oil well includes a main wellbore and multiple branch wellbores connected to the main wellbore. The multiple branch wellbores are of equal length, have equal angles with the main wellbore, and are equidistant from each other. Each branch wellbore includes at least one intermediate branch wellbore, the end of which is located on the vertical axis of the main wellbore. The device includes: The first acquisition unit is used to acquire oil well data, which includes the length of the main wellbore, the radius of the main wellbore, the length of the branch wellbore, the angle between the branch wellbore and the main wellbore, the distance between the ends of adjacent branch wellbores, and the number and radius of the branch wellbores. The first generation unit is used to generate an elliptical oil well region on a first auxiliary plane based on the oil well data. The elliptical oil well region is an elliptical region defined by the end of the intermediate branch wellbore and the two ends of the main wellbore. The elliptical oil well region has a first major axis and a first minor axis. The second generation unit is used to generate an elliptical oil supply area on the first auxiliary plane based on the oil well data. The elliptical oil supply area is an elliptical area located around the elliptical oil well area and used to supply oil to the elliptical oil well area. The elliptical oil supply area is confocal with the elliptical oil well area and has a second major axis and a second minor axis. The first determining unit is used to determine the focal coordinates of the elliptical oil well area and the elliptical oil supply area, with the center point of the elliptical oil well area as the origin of the coordinate system, the first major axis as the x-axis, and the first minor axis as the y-axis, based on the lengths of the first major axis and the first minor axis, or based on the lengths of the second major axis and the second minor axis. The transformation unit is used to transform the elliptical oil well area and the elliptical oil supply area on the first auxiliary plane into a circular oil well area and a circular oil supply area on the second auxiliary plane. The second determining unit is used to determine the radius of the circular oil well region based on the focal coordinates, the length of the first major axis, and the length of the first minor axis. The third determining unit is used to determine the radius of the circular oil supply area based on the focal coordinates, the length of the second major axis, and the length of the second minor axis. The second acquisition unit is used to acquire formation oil data; A unit is established to: ...

7. An equipment for establishing an oil well productivity calculation model, characterized in that, include: The processor, memory, communication interface, and communication bus are provided, wherein the processor, memory, and communication interface communicate with each other via the communication bus. The memory is used to store at least one executable instruction that causes the processor to perform the operation of the oil well productivity calculation model establishment method as described in any one of claims 1-4.

8. A computer-readable storage medium, characterized in that, The storage medium stores at least one executable instruction, which, when run on the oil well productivity determination device, causes the oil well productivity determination device to perform the operation of the oil well productivity calculation model establishment method as described in any one of claims 1-4.

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