Prediction Method and Device for the Ultimate Recovery (EUR) of Shale Oil Volume Fracturing Wells

Abstract

An embodiment of the present invention discloses a method and device for predicting the ultimate recovery (EUR) of a shale oil volume fracturing well. The method includes: determining the oil production per unit flow pressure drop in a first preset time period and the oil production per unit flow pressure drop in a second preset time period; analyzing the oil production per unit flow pressure drop in the first preset time period and the oil production per unit flow pressure drop in the second preset time period by using at least one decline analysis method to determine a target decline analysis model; determining the predicted result of the oil production per unit flow pressure drop in a third preset time period based on the target decline analysis model; and determining the predicted productivity according to the predicted result of the oil production per unit flow pressure drop and the predicted result of the bottom-hole flowing pressure in the third preset time period. By implementing this solution, the accuracy of cumulative oil production prediction can be improved, the analysis time can be shortened, the prediction difficulty can be reduced, and a scientific basis can be provided for the production effect evaluation and development plan formulation of shale oil reservoir volume fracturing wells.

Description

Technical Field

[0001] The embodiments of the present invention relate to the technical field of oil and gas exploration, and particularly to a method and device for predicting the ultimate recovery (EUR) of a shale oil volume fracturing well. Background Art

[0002] Predicting the ultimate oil production of a shale oil volume fracturing well is an important basis for evaluating the production effect of a shale oil volume fracturing well and formulating a development plan. Due to the complex fracture characteristics and seepage laws of shale oil reservoir volume fracturing wells, and the significant pressure changes during the production process, it is difficult to predict the ultimate oil production, which has become a key technical bottleneck in the efficient development of shale oil reservoirs.

[0003] The productivity prediction methods and defects of shale oil volume fracturing wells in related technologies are as follows: The numerical methods for future production prediction face the problems of lack of basic data and long time consumption; while the analytical method models have significant differences from the actual formation conditions; although the decline analysis method has the advantages of simplicity and speed, it still needs to be further improved according to the development characteristics of shale oil. Summary of the Invention

[0004] The embodiments of the present invention provide a method and device for predicting the ultimate recovery (EUR) of a shale oil volume fracturing well, which can improve the accuracy of cumulative oil production prediction, shorten the analysis time, reduce the prediction difficulty, and provide a scientific basis for the production effect evaluation and development plan formulation of shale oil reservoir volume fracturing wells.

[0005] In a first aspect, the embodiments of the present invention provide a method for predicting the ultimate recovery (EUR) of a shale oil volume fracturing well, the method comprising: determining the oil production per unit flow pressure drop in a standard period within a first preset time period of the shale oil volume fracturing well, and the oil production per unit flow pressure drop in a standard period within a second preset time period of the shale oil volume fracturing well;

[0006] Analyzing the oil production per unit flow pressure drop and the oil production per unit flow pressure drop by using at least one decline analysis method to determine a target decline analysis model;

[0007] Determining the predicted result of the oil production per unit flow pressure drop of the shale oil volume fracturing well within a third preset time period based on the target decline analysis model;

[0008] Determining the predicted productivity of the shale oil volume fracturing well within the third preset time period according to the predicted result of the oil production per unit flow pressure drop and the predicted result of the bottom-hole flowing pressure within the third preset time period; wherein, the predicted result of the bottom-hole flowing pressure is predicted based on the bottom-hole flowing pressure data within the first preset time period and the bottom-hole flowing pressure data within the second preset time period.

[0009] Second aspect, an embodiment of the present invention further provides a prediction device for the ultimate recovery (EUR) of a shale oil volume fracturing well. The device includes: a unit flow pressure drop oil production determination module, configured to determine a first unit flow pressure drop oil production of the shale oil volume fracturing well in a standard period within a first preset time period, and a second unit flow pressure drop oil production of the shale oil volume fracturing well in a standard period within a second preset time period;

[0010] A target decline analysis model determination module, configured to analyze the first unit flow pressure drop oil production and the second unit flow pressure drop oil production by using at least one decline analysis method to determine a target decline analysis model;

[0011] A unit flow pressure drop oil production prediction result determination module, configured to determine a prediction result of the unit flow pressure drop oil production of the shale oil volume fracturing well in a third preset time period based on the target decline analysis model;

[0012] A predicted production capacity determination module, configured to determine the predicted production capacity of the shale oil volume fracturing well in a third preset time period according to the prediction result of the unit flow pressure drop oil production and the predicted bottom hole flowing pressure result in the third preset time period; wherein, the predicted bottom hole flowing pressure result is predicted based on the bottom hole flowing pressure data in the first preset time period and the bottom hole flowing pressure data in the second preset time period.

[0013] Third aspect, an embodiment of the present invention further provides an electronic device, which includes:

[0014] One or more processors;

[0015] A storage device, configured to store one or more programs,

[0016] When the one or more programs are executed by the one or more processors, the one or more processors implement the prediction method for the ultimate recovery (EUR) of a shale oil volume fracturing well as described in any one of the embodiments of the present invention.

[0017] Fourth aspect, an embodiment of the present invention further provides a computer-readable storage medium, on which a computer program is stored, and when the program is executed by a processor, it implements the prediction method for the ultimate recovery (EUR) of a shale oil volume fracturing well as described in any one of the embodiments of the present invention.

[0018] The technical solution provided by the embodiment of the present invention determines the oil production per unit flow pressure drop in the standard period of the shale oil volume fracturing well in the first preset time period, and the oil production per unit flow pressure drop in the standard period of the shale oil volume fracturing well in the second preset time period; analyzes the oil production per unit flow pressure drop in the first preset time period and the oil production per unit flow pressure drop in the second preset time period by using at least one decline analysis method to determine the target decline analysis model; determines the predicted result of the oil production per unit flow pressure drop of the shale oil volume fracturing well in the third preset time period based on the target decline analysis model; determines the predicted production capacity of the shale oil volume fracturing well in the third preset time period according to the predicted result of the oil production per unit flow pressure drop and the predicted bottom-hole flowing pressure result in the third preset time period; wherein, the predicted bottom-hole flowing pressure result is predicted based on the bottom-hole flowing pressure data in the first preset time period and the bottom-hole flowing pressure data in the second preset time period. By implementing the technical solution provided by the embodiment of the present invention, the accuracy of the cumulative oil production prediction can be improved, the analysis time can be shortened, the prediction difficulty can be reduced, and a scientific basis can be provided for the production effect evaluation and development plan formulation of the shale oil reservoir volume fracturing well. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 is a flowchart of a method for predicting the ultimate recoverable (EUR) of a shale oil volume fracturing well provided by an embodiment of the present invention;

[0020] Figure 2 is a flowchart of another method for predicting the ultimate recoverable (EUR) of a shale oil volume fracturing well provided by an embodiment of the present invention;

[0021] Figure 3 is a comparison diagram of the predicted results of the oil production per unit flow pressure drop of different candidate decline analysis models for the 0-150th day and the actual oil production per unit flow pressure drop of the 0-150th day of a shale oil volume fracturing well provided by an embodiment of the present invention;

[0022] Figure 4 is a comparison diagram of the total predicted oil production per unit flow pressure drop of different candidate decline analysis models within 0-150 days and the total actual oil production per unit flow pressure drop of the second unit within 0-150 days of a shale oil volume fracturing well provided by an embodiment of the present invention;

[0023] Figure 5 is a schematic diagram of the historical bottom-hole flowing pressure data and the predicted bottom-hole flowing pressure results for each day within the third preset time period determined by using the flowing pressure change model provided by an embodiment of the present invention;

[0024] Figure 6 is a schematic structural diagram of a device for predicting the ultimate recoverable (EUR) of a shale oil volume fracturing well provided by an embodiment of the present invention;

[0025] Figure 7 is a schematic structural diagram of an electronic device provided by an embodiment of the present invention. Detailed implementation manners

[0026] The present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It can be understood that the specific embodiments described herein are only used to explain the present invention, rather than limiting the present invention. Additionally, it should be noted that for the sake of description, only parts related to the present invention rather than all structures are shown in the accompanying drawings.

[0027] Figure 1 is a flowchart of a method for predicting the ultimate recovery (EUR) of a shale oil volume fracturing well provided by an embodiment of the present invention. The method can be executed by a prediction device for the ultimate recovery (EUR) of a shale oil volume fracturing well. The device can be implemented in a software and / or hardware manner and can be configured in an electronic device for predicting the ultimate recovery (EUR) of a shale oil volume fracturing well. The method is applied to a scenario for predicting the ultimate oil production of a shale oil volume fracturing well. As Figure 1 shown, the technical solution provided by the embodiment of the present invention specifically includes:

[0028] S110: Determine the oil production per unit flowing pressure drop in the standard period of the shale oil volume fracturing well in the first preset time period, and the oil production per unit flowing pressure drop in the standard period of the shale oil volume fracturing well in the second preset time period.

[0029] Among them, the first preset time period can be half a year, the first preset time period can be 4 months, and the first preset time period can be set according to actual needs. The second preset time period can be 3 months, the second preset time period can be 2 months, and the second preset time period can be set according to actual needs. The time length of the first preset time period and the time length of the second preset time period can be the same or different. Preferably, the time length of the first preset time period is the same as the time length of the second preset time period. The standard period can be 12h, the standard period can be 24h, and the standard period can be set according to actual needs. The oil production per unit flowing pressure drop in the standard period can be determined by the bottom hole flowing pressure, the initial bottom hole flowing pressure of the shale oil volume fracturing well in the standard period, and the oil production in the standard period. This solution can determine the oil production per unit flowing pressure drop in the standard period of the shale oil volume fracturing well in the first preset time period, and the oil production per unit flowing pressure drop in the standard period of the shale oil volume fracturing well in the second preset time period.

[0030] S120: Analyze the first oil production per unit flowing pressure drop and the second oil production per unit flowing pressure drop by using at least one decline analysis method to determine the target decline analysis model.

[0031] Among them, this solution can use the oil production per unit flowing pressure drop in the first unit as the fitting data set, and the oil production per unit flowing pressure drop in the second unit as the verification data set. Then, at least one decline analysis method is used to fit the oil production per unit flowing pressure drop in the first unit to determine the decline parameters and obtain the corresponding candidate decline analysis models. Using the determined candidate decline analysis models, predict the oil production per unit flowing pressure drop at the standard time period within the second preset time period respectively. Then, determine the sum of the oil production per unit flowing pressure drop at the standard time period within the second preset time period predicted by each candidate decline analysis model respectively, and calculate the difference between this sum and the sum of the oil production per unit flowing pressure drop in the second unit. Determine the optimal decline analysis model, that is, the target decline analysis model, from each candidate decline analysis model according to the principle of the smallest difference. Among them, the decline analysis method can be the Duong decline method, the decline analysis method can also be the SEPD decline method, the decline analysis method can also be the Arps hyperbolic decline method, and the decline analysis method can be set according to actual needs.

[0032] S130: Determine the prediction result of the oil production per unit flowing pressure drop of the shale oil volume fracturing well within the third preset time period based on the target decline analysis model.

[0033] Among them, the third preset time period can be one year, and the third preset time period can also be two years. The third preset time period can be set according to actual needs. This solution can predict the oil production per unit flowing pressure drop at the standard time period of the shale oil volume fracturing well within the third preset time period based on the determined target decline analysis model, and according to the oil production per unit flowing pressure drop in the first unit at the standard time period within the first preset time period of the shale oil volume fracturing well and the oil production per unit flowing pressure drop in the second unit at the standard time period within the second preset time period of the shale oil volume fracturing well.

[0034] S140: Determine the predicted production capacity of the shale oil volume fracturing well within the third preset time period according to the prediction result of the oil production per unit flowing pressure drop and the prediction result of the bottom-hole flowing pressure within the third preset time period.

[0035] Among them, the prediction result of the bottom-hole flowing pressure is predicted based on the bottom-hole flowing pressure data within the first preset time period and the bottom-hole flowing pressure data within the second preset time period.

[0036] Specifically, the bottom-hole flowing pressure during the standard time periods within the first preset time period and the second preset time period can be obtained by processing the wellhead pressure data during the standard time periods through a wellbore multiphase flow calculation method, such as parameters like the depth of a shale oil volume fracturing well, gas-liquid ratio, water cut, geothermal gradient, and the friction coefficient of the wellbore inner wall. This solution can determine the bottom-hole flowing pressure data within the first preset time period and the bottom-hole flowing pressure data within the second preset time period, and then use a nonlinear regression method to determine the mathematical model of the flowing pressure change. By analyzing the bottom-hole flowing pressure data within the first preset time period and the bottom-hole flowing pressure data within the second preset time period through the mathematical model of the flowing pressure change, the predicted results of the bottom-hole flowing pressure for each standard time period within the third preset time period can be determined. Among them, the relationship between the oil production per unit flowing pressure drop during the standard time period, the bottom-hole flowing pressure during the standard time period, and the predicted production capacity during the standard time period is: the predicted production capacity during the standard time period = the oil production per unit flowing pressure drop during the standard time period × (the initial bottom-hole flowing pressure - the bottom-hole flowing pressure during the standard time period).

[0037] In addition, after determining the predicted production capacity of the shale oil volume fracturing well within the third preset time period, this solution can also adjust the predicted production capacity within the third preset time period according to the characteristics of the shale oil volume fracturing well. For example, if the third preset time period reaches the preset production years, or if the predicted production capacity of the shale oil volume fracturing well per day within the third preset time period drops to the preset minimum daily production, then control the shale oil volume fracturing well to stop oil production. Or, compare the time point when the predicted bottom-hole flowing pressure within the third preset time period is less than the bubble point pressure with the time point when the target decline analysis model within the third preset time period enters the boundary control flow. If the former is earlier than the latter, then use a linear flow control mode to adjust the predicted production capacity per day of the shale oil volume fracturing well within the third preset time period. If the former is later than the latter, then use a boundary flow control mode to adjust the predicted production capacity per day of the shale oil volume fracturing well within the third preset time period.

[0038] The technical solution provided by the embodiments of the present invention determines the oil production per unit flowing pressure drop in the standard period of the shale oil volume fracturing well in the first preset time period, and the oil production per unit flowing pressure drop in the standard period of the shale oil volume fracturing well in the second preset time period; uses at least one decline analysis method to analyze the oil production per unit flowing pressure drop in the first preset time period and the oil production per unit flowing pressure drop in the second preset time period to determine the target decline analysis model; determines the predicted result of the oil production per unit flowing pressure drop of the shale oil volume fracturing well in the third preset time period based on the target decline analysis model; determines the predicted production capacity of the shale oil volume fracturing well in the third preset time period according to the predicted result of the oil production per unit flowing pressure drop and the predicted bottom-hole flowing pressure in the third preset time period; wherein, the predicted bottom-hole flowing pressure result is predicted based on the bottom-hole flowing pressure data in the first preset time period and the bottom-hole flowing pressure data in the second preset time period. By implementing the technical solution provided by the embodiments of the present invention, the accuracy of the cumulative oil production prediction can be improved, the analysis time can be shortened, the prediction difficulty can be reduced, and a scientific basis can be provided for the production effect evaluation and development plan formulation of the shale oil reservoir volume fracturing well.

[0039] Figure 2 is a flowchart of the prediction method for the ultimate recovery (EUR) of the shale oil volume fracturing well provided by the embodiments of the present invention. This embodiment is optimized on the basis of the above embodiment. As Figure 2 shown, the prediction method for the ultimate recovery (EUR) of the shale oil volume fracturing well in the embodiments of the present invention may include:

[0040] S210: Determine the oil production per unit flowing pressure drop in the standard period of the shale oil volume fracturing well in the first preset time period, and the oil production per unit flowing pressure drop in the standard period of the shale oil volume fracturing well in the second preset time period.

[0041] S220: Use at least one decline analysis method to analyze the oil production per unit flowing pressure drop to determine at least one candidate decline analysis model.

[0042] Among them, this solution can use at least one decline analysis method to fit the oil production per unit flowing pressure drop data in the first preset time period, determine the decline parameters, and construct the corresponding decline analysis model, that is, the candidate decline analysis model. For example, this solution can use the improved Duong decline method to fit the oil production per unit flowing pressure drop data in the first preset time period, determine the decline parameters, and construct the corresponding candidate decline analysis model. Among them, the decline equation of the improved Duong decline method is as follows:

[0043]

[0044] wherein, δ is the oil production per unit flowing pressure drop in the first preset time period, with the unit of t / d; δ iis the maximum oil production per unit flow pressure drop within the first preset time period; λ p is the cumulative oil production per unit flow pressure drop within the first preset time period; both a and m are decreasing coefficients, which can be determined by fitting the first oil production per unit flow pressure drop data through the above formula; t is the standard time period, such as days.

[0045] S230: Based on each candidate decline analysis model, respectively determine the predicted oil production per unit flow pressure drop for the standard time period within the second preset time period.

[0046] Among them, this solution can respectively determine the predicted oil production per unit flow pressure drop for the standard time period within the second preset time period based on each candidate decline analysis model determined in the foregoing steps. Exemplarily, the predicted results of the oil production per unit flow pressure drop for days 0 - 150 using the candidate decline analysis model determined by the Duong decline method, the predicted results of the oil production per unit flow pressure drop for days 0 - 150 using the candidate decline analysis model determined by the SEPD decline method, and the predicted results of the oil production per unit flow pressure drop for days 0 - 150 using the candidate decline analysis model determined by the Arps hyperbolic decline method are compared with the actual oil production per unit flow pressure drop for days 0 - 150 as shown in Figure 3 shown.

[0047] S240: Determine the total second oil production per unit flow pressure drop for the standard time period within the second preset time period, and determine the total oil production per unit flow pressure drop for the standard time period predicted by each candidate decline analysis model within the second preset time period.

[0048] Exemplarily, the cumulative results of the predicted oil production per unit flow pressure drop for days 0 - 150 using the candidate decline analysis model determined by the Duong decline method, the cumulative results of the predicted oil production per unit flow pressure drop for days 0 - 150 using the candidate decline analysis model determined by the SEPD decline method, and the cumulative results of the predicted oil production per unit flow pressure drop for days 0 - 150 using the candidate decline analysis model determined by the Arps hyperbolic decline method are compared with the actual cumulative oil production per unit flow pressure drop for days 0 - 150 as shown in Figure 4 shown.

[0049] S250: Determine the target decline analysis model according to the difference between the total second oil production per unit flow pressure drop and the total oil production per unit flow pressure drop for the predicted standard time period.

[0050] Exemplarily, as shown in Figure 4 shown, assume that there are 3 candidate decline analysis models determined by analyzing the first oil production per unit flow pressure drop using at least one decline analysis method. By Figure 4It can be seen that the sum of the predicted oil production per unit flow pressure drop within 0 - 150 days predicted by the candidate decline analysis model determined by the Duong decline method has the smallest difference from the actual sum of the oil production per unit flow pressure drop of the second unit within 0 - 150 days. Therefore, the candidate decline analysis model determined by the Duong decline method can be used as the target decline analysis model.

[0051] S260: Determine the predicted result of the oil production per unit flow pressure drop of the shale oil volume fracturing well within the third preset time period based on the target decline analysis model.

[0052] Specifically, this solution can use the target decline analysis model determined in the foregoing steps to determine the predicted result of the oil production per unit flow pressure drop of the shale oil volume fracturing well within the third preset time period. For example, determine the predicted value of the oil production per unit flow pressure drop of the shale oil volume fracturing well every day within the third preset time period.

[0053] S270: Determine the predicted production capacity of the shale oil volume fracturing well within the third preset time period according to the predicted result of the oil production per unit flow pressure drop and the predicted result of the bottom hole flowing pressure within the third preset time period.

[0054] In a feasible implementation manner, optionally, the process of determining the predicted result of the bottom hole flowing pressure includes: determining the bottom hole flowing pressure data of the standard time period within the first preset time period and the bottom hole flowing pressure data of the standard time period within the second preset time period; using the nonlinear regression method to analyze each of the bottom hole flowing pressure data to determine the flowing pressure change model; and determining the predicted result of the bottom hole flowing pressure within the third preset time period based on the flowing pressure change model.

[0055] Exemplarily, this solution can obtain the bottom hole flowing pressure data of the standard time period within the first preset time period and the bottom hole flowing pressure data of the standard time period within the second preset time period, and determine the mathematical model of the flowing pressure change by using the nonlinear regression method according to the characteristics of the bottom hole flowing pressure change after the shale oil volume fracturing well is put into production. Then, based on the mathematical model of the flowing pressure change, predict the future flowing pressure change law, that is, the predicted result of the bottom hole flowing pressure within the third preset time period. Figure 5 Shows the historical bottom hole flowing pressure data and the predicted result of the bottom hole flowing pressure every day within the third preset time period determined by using the flowing pressure change model.

[0056] Thus, by determining the bottom hole flowing pressure data of the standard time period within the first preset time period and the bottom hole flowing pressure data of the standard time period within the second preset time period; using the nonlinear regression method to analyze each of the bottom hole flowing pressure data to determine the flowing pressure change model; and determining the predicted result of the bottom hole flowing pressure within the third preset time period based on the flowing pressure change model. It is possible to predict the future bottom hole flowing pressure of the shale oil volume fracturing well, and further provide a reliable data source for accurately predicting the future production capacity of the shale oil volume fracturing well.

[0057] In this embodiment, optionally, the process of determining the bottom-hole flowing pressure data for the standard time period includes: processing the wellhead pressure data for each day within the first preset time period and the second preset time period based on the wellbore multiphase flow calculation method to determine the bottom-hole flowing pressure data for each day.

[0058] Exemplarily, the wellbore multiphase flow calculation method can be the Beggs-brill model, which is a method applicable to the calculation of horizontal, vertical, and arbitrarily inclined gas-liquid two-phase pipe flows. In polypropylene pipes with lengths of 15 m, diameters of 25.4 mm and 38 mm, Beggs and Brill conducted experiments with air and water and proposed this method based on the experimental results. It is also a relatively common method currently used for calculating the multiphase flow in the wellbores of straight and inclined wells, directional wells, and horizontal wells. Among them, the wellhead pressure data can be parameters such as the depth of the shale oil volume fracturing well, gas-liquid ratio, water cut, geothermal gradient, and friction coefficient of the wellbore inner wall. This solution can process the wellhead pressure data for each day within the first preset time period and the second preset time period based on the wellbore multiphase flow calculation method to determine the bottom-hole flowing pressure data for each day within the first preset time period and the second preset time period.

[0059] Thus, by determining the bottom-hole flowing pressure data for each day within the first preset time period and the second preset time period, a reliable data source can be provided for predicting the future bottom-hole flowing pressure data.

[0060] In another feasible implementation manner, optionally, according to the predicted oil production per unit flow pressure drop and the predicted bottom-hole flowing pressure within the third preset time period, determining the predicted production capacity of the shale oil volume fracturing well within the third preset time period includes: determining the predicted production capacity of the shale oil volume fracturing well for each day within the third preset time period based on the following formula:

[0061] q = δ×(p wfi - p wf );

[0062] where q represents the predicted production capacity of the shale oil volume fracturing well for each day within the third preset time period, δ represents the predicted oil production per unit flow pressure drop of the shale oil volume fracturing well for each day within the third preset time period; p wfi represents the initial bottom-hole flowing pressure, and p wf represents the predicted bottom-hole flowing pressure of the shale oil volume fracturing well for each day within the third preset time period.

[0063] Exemplarily, the initial bottom-hole flowing pressure can be the bottom-hole flowing pressure when the shale oil volume fracturing well is put into use. Assume that the oil production per unit flowing pressure drop of the shale oil volume fracturing well on a certain day within the third preset time period is 2.5 t / MPa, the initial bottom-hole flowing pressure is 15 MPa, and the predicted bottom-hole flowing pressure of the shale oil volume fracturing well on the same day within the third preset time period is 10 MPa. Then, the predicted production capacity of the shale oil volume fracturing well on that day within the third preset time period is 12.5 t / d.

[0064] Thus, by predicting the production capacity of the shale oil volume fracturing well based on the oil production per unit flowing pressure drop and the bottom-hole flowing pressure, the coupled analysis of production and pressure is achieved, avoiding the error caused by only considering the change in single production, being more adaptable to the significant pressure change characteristics during the shale oil development process, and making the prediction of the production capacity of the shale oil volume fracturing well more accurate and scientific.

[0065] In this embodiment, optionally, the predicted production capacity of the shale oil volume fracturing well within the third preset time period is determined according to the size relationship between the third preset time period and the preset production years, and / or according to the size relationship between the predicted production capacity of the shale oil volume fracturing well every day within the third preset time period and the preset minimum daily production.

[0066] Exemplarily, assume that the preset production years is one year and the third preset time period is two years, that is, the third preset time period is greater than the preset production years. This solution can use the predicted production capacity of the shale oil volume fracturing well within one year as the predicted production capacity within the third preset time period to control the shale oil volume fracturing well to stop producing oil after one year. This solution can also determine the relative size relationship between the predicted production capacity of the shale oil volume fracturing well every day within the third preset time period and the preset minimum daily production. When it is determined that the predicted production capacity of the shale oil volume fracturing well on a certain day within the third preset time period drops to the preset minimum daily production, the shale oil volume fracturing well is controlled to stop producing oil.

[0067] Thus, by determining the predicted production capacity of the shale oil volume fracturing well within the third preset time period according to the size relationship between the third preset time period and the preset production years, and / or according to the size relationship between the predicted production capacity of the shale oil volume fracturing well every day within the third preset time period and the preset minimum daily production, the production capacity of the shale oil volume fracturing well can be flexibly adjusted, and then the production capacity of the shale oil volume fracturing well can be controlled.

[0068] In yet another feasible implementation manner, optionally, after determining the predicted production capacity of the shale oil volume fracturing well within the third preset time period, the method further includes: determining a first target time when the bottom-hole flowing pressure prediction result within the third preset time period is less than the bubble point pressure; determining a second target time when the target decline analysis model enters the boundary control flow within the third preset time period; and determining an adjustment strategy for the predicted daily production capacity of the shale oil volume fracturing well within the third preset time period according to the sequence relationship between the first target time and the second target time.

[0069] Exemplarily, on the basis of determining the predicted production capacity of the shale oil volume fracturing well within the third preset time period, this solution can also determine the time when the bottom-hole flowing pressure prediction result within the third preset time period is less than the bubble point pressure, that is, the first target time. And determine the time when the target decline analysis model enters the boundary control flow within the third preset time period, that is, the second target time. Among them, the bubble point pressure can be determined by PVT experiments or gas-liquid non-equilibrium calculation methods. The time when the target decline analysis model enters the boundary control flow can be determined by the change trend of the daily oil production in the standard time period within the third preset time period. That is, entering the boundary control flow means that the pressure wave of the shale oil volume fracturing well has significantly propagated to the boundary. At this time, under the double logarithmic coordinate axis with the horizontal axis being time, such as days, and the vertical axis being the daily oil production within the third preset time period, the slope of the pressure derivative curve is 1, and this time is the second target time. If the first target time is earlier than the second target time, it means that the shale oil volume fracturing well is in the linear flow stage, and the following formula is used to adjust the predicted daily production capacity of the shale oil volume fracturing well within the time period after the bottom-hole flowing pressure is less than the bubble point pressure within the third preset time period:

[0070]

[0071] where q o-t-l represents the daily oil production after gas production in the linear flow stage, with the unit of t / d; q o-s-l represents the daily oil production before gas production in the linear flow stage, that is, the daily oil production predicted according to the unit flow pressure drop oil production prediction result and the bottom-hole flowing pressure prediction result within the third preset time period; k o-t represents the effective oil-phase permeability after gas production, with the unit of mD; k o-s represents the effective oil-phase permeability before gas production; μ o-t represents the viscosity of the crude oil after gas production, with the unit of cp; μ o-s represents the viscosity of the crude oil before gas production. According to the above formula, determine the adjusted daily oil production as the selected predicted production capacity.

[0072] If the first target time is later than the second target time, it indicates that the shale oil volume fracturing well enters the boundary control flow stage. The following formula is used to adjust the predicted daily production capacity of the shale oil volume fracturing well every day during the period after the bottom-hole flowing pressure is less than the bubble point pressure within the third preset time period:

[0073]

[0074] Wherein, q o-t-b represents the daily oil production after gas production in the boundary control flow stage; q o-s-b represents the daily oil production before gas production in the boundary control flow stage, that is, the daily oil production predicted according to the predicted result of the oil production per unit flow pressure drop and the predicted result of the bottom-hole flowing pressure within the third preset time period. According to the above formula, the adjusted daily oil production is determined as the selected predicted production capacity.

[0075] Thus, by determining the first target time when the predicted result of the bottom-hole flowing pressure within the third preset time period is less than the bubble point pressure; determining the second target time when the target decline analysis model enters the boundary control flow within the third preset time period; and determining the adjustment strategy of the predicted daily production capacity of the shale oil volume fracturing well every day within the third preset time period according to the sequence relationship between the first target time and the second target time. It is possible to adjust the daily oil production according to the pressure control mode of the shale oil volume fracturing well, and then scientifically predict and control the production capacity of the shale oil volume fracturing well.

[0076] The technical solution provided by the embodiment of the present invention includes determining the first oil production per unit flow pressure drop in the standard period within the first preset time period of the shale oil volume fracturing well, and the second oil production per unit flow pressure drop in the standard period within the second preset time period of the shale oil volume fracturing well; analyzing the first oil production per unit flow pressure drop by using at least one decline analysis method to determine at least one candidate decline analysis model; based on each candidate decline analysis model, respectively determining the predicted oil production per unit flow pressure drop in the standard period within the second preset time period; determining the total sum of the second oil production per unit flow pressure drop in the standard period within the second preset time period, and determining the total sum of the oil production per unit flow pressure drop in the standard period predicted by each candidate decline analysis model within the second preset time period; determining the target decline analysis model according to the difference between the total sum of the second oil production per unit flow pressure drop and the total sum of the predicted oil production per unit flow pressure drop in the standard period; determining the predicted result of the oil production per unit flow pressure drop of the shale oil volume fracturing well within the third preset time period based on the target decline analysis model; and determining the predicted production capacity of the shale oil volume fracturing well within the third preset time period according to the predicted result of the oil production per unit flow pressure drop and the predicted result of the bottom-hole flowing pressure within the third preset time period. By implementing this solution, it is possible to improve the accuracy of the predicted cumulative oil production, shorten the analysis time, reduce the prediction difficulty, and provide a scientific basis for the production effect evaluation and development plan formulation of the shale oil reservoir volume fracturing well.

[0077] To more clearly describe the technical solution of the present invention, the technical solution provided by the embodiments of the present invention may further include the following steps:

[0078] Step 1: Process the wellhead pressure data of each day within the first preset time period and the second preset time period based on the wellbore multiphase flow calculation method to determine the bottom-hole flowing pressure data of each day.

[0079] Step 2: Determine the oil production per unit flowing pressure drop in the standard period of the shale oil volume fracturing well within the first preset time period, and the oil production per unit flowing pressure drop in the standard period of the shale oil volume fracturing well within the second preset time period.

[0080] Among them, in this solution, the oil production per unit flowing pressure drop corresponding to the first 2 / 3 time period (0 - 2t / 3) after the production of the shale oil volume fracturing well can be selected as dataset 1 (fitting data, Figure 2 ), and the oil production per unit flowing pressure drop corresponding to the latter 1 / 3 time period (2t / 3 - t) can be selected as dataset 2 (verification data).

[0081] Step 3: Analyze the first oil production per unit flowing pressure drop using at least one decline analysis method to determine at least one candidate decline analysis model.

[0082] Among them, in this solution, more than 3 different types of decline analysis methods can be used to fit dataset 1 within the time period (0 - 2t / 3), determine the decline parameters, and construct the corresponding candidate decline analysis models.

[0083] Step 4: Based on each candidate decline analysis model, respectively determine the predicted oil production per unit flowing pressure drop in the standard period within the second preset time period.

[0084] Step 5: Determine the total oil production per unit flowing pressure drop in the standard period within the second preset time period, and determine the total oil production per unit flowing pressure drop in the standard period predicted by each candidate decline analysis model within the second preset time period.

[0085] Step 6: Determine the target decline analysis model according to the difference between the total oil production per unit flowing pressure drop and the total predicted oil production per unit flowing pressure drop in the standard period.

[0086] Among them, in this solution, more than 3 candidate decline analysis models constructed can be respectively used to continue predicting the oil production per unit flowing pressure drop in the time period (2t / 3 - t), and compared with dataset 2. According to the principle that the cumulative oil production difference at the t time point is the smallest, the optimal decline analysis model, that is, the target decline analysis model, is selected.

[0087] Step 7: Based on the target decline analysis model, determine the prediction result of the oil production per unit flowing pressure drop of the shale oil volume fracturing well within the third preset time period.

[0088] Among them, this solution can predict the change in the oil production per unit flow pressure drop of a shale oil volume fracturing well in the future according to the selected decreasing analysis model.

[0089] Step 8: Determine the bottom-hole flowing pressure data of the standard period within the first preset time period and the bottom-hole flowing pressure data of the standard period within the second preset time period; use the non-linear regression method to analyze each of the bottom-hole flowing pressure data to determine the flowing pressure change model; based on the flowing pressure change model, determine the prediction result of the bottom-hole flowing pressure within the third preset time period.

[0090] Among them, this solution can determine the mathematical model of the flowing pressure change by using the non-linear regression method according to the characteristics of the bottom-hole flowing pressure change after the production of the shale oil volume fracturing well, and then predict the future law of the bottom-hole flowing pressure change.

[0091] Step 9: Determine the predicted production capacity of the shale oil volume fracturing well within the third preset time period according to the prediction result of the oil production per unit flow pressure drop and the prediction result of the bottom-hole flowing pressure within the third preset time period.

[0092] Among them, this solution can comprehensively consider the future oil production per unit flow pressure drop and the law of the flowing pressure change, and calculate and determine the law of the future oil production change.

[0093] Step 10: Determine the first target time when the prediction result of the bottom-hole flowing pressure within the third preset time period is less than the bubble point pressure, determine the second target time when the target decreasing analysis model enters the boundary control flow within the third preset time period, and determine the adjustment strategy of the predicted daily production capacity of the shale oil volume fracturing well every day within the third preset time period according to the sequence relationship between the first target time and the second target time.

[0094] Among them, this solution can adjust the daily oil production of the shale oil volume fracturing well according to the pressure control mode.

[0095] Step 11: Determine the predicted production capacity of the shale oil volume fracturing well within the third preset time period according to the size relationship between the third preset time period and the preset production life, and / or according to the size relationship between the predicted daily production capacity of the shale oil volume fracturing well every day within the third preset time period and the preset minimum daily production.

[0096] Among them, this solution can calculate the future cumulative oil production, and determine the final oil recovery of the shale oil volume fracturing well with the production life or the lower limit of the daily oil production as the constraint. That is, set the production life as t, and the cumulative production obtained when the time is equal to t is regarded as the final oil recovery, or set the cumulative production obtained when the daily oil production decreases to qlimit as the final oil recovery.

[0097] In the related art, there are mainly three methods for predicting the oil production in an oil well group: The first is the numerical method. By constructing a single-well numerical model and combining with the analysis of seepage mechanism, on the basis of historical fitting, the model is further improved and production dynamic prediction is carried out. This method requires a large number of parameters, takes a long time to model and predict, and the prediction process is relatively complex, and it is less applicable to shale oil reservoirs lacking basic data and requiring simple and rapid prediction.

[0098] The second method is the analytical equation method. The common analytical models of volume-fractured horizontal wells in shale oil mainly include the three-linear flow model and the five-linear flow, etc. According to the equivalent seepage theory, assuming the fracture shape, the flow in the fracture is simplified as linear flow or radial flow, the fracture network is equivalent to a high-permeability zone, and the characteristics of the fracture network are characterized by the number, volume and permeability of the high-permeability zone. The model focuses on characterizing the overall fracture network characteristics and flow patterns of volume-fractured horizontal wells. However, there are many assumptions in the analytical method, the constructed fracture shape is relatively ideal, and it is difficult to be used for EUR prediction under the complex phase change and seepage characteristics of shale oil.

[0099] The third method is the decline analysis method. This method is based on the production decline characteristics of volume-fractured wells in shale oil, uses a specific mathematical relationship to fit the production change, so as to obtain the corresponding decline parameters, and then constructs the decline model of the well, and predicts the future oil production and EUR of the oil well. This method has the advantages of simplicity, rapidity and less required basic data. At the same time, if the model is properly selected, the characterization of the complex phase change and seepage characteristics of shale oil can be realized. However, the traditional production decline method is mainly aimed at shale gas reservoirs or foreign shale oil, and does not fully consider the characteristics of significant pressure change, short production start-up time and phase change during the development process of shale oil in China, resulting in relatively low accuracy of direct application.

[0100] To sum up, the numerical method for future production prediction faces the problem of lack of basic data and takes a long time, while there are significant differences between the analytical method model and the actual formation conditions. Although the decline analysis method has the advantages of simplicity and rapidity, it still needs to be further improved according to the development characteristics of shale oil in China. Therefore, it is necessary to develop a method for predicting the ultimate oil production of volume-fractured wells in shale oil by coupling analysis of pressure and production, so as to achieve rapid, simple and accurate prediction, and provide a basis for the formulation of development plans and the evaluation of development effects.

[0101] The technical solution provided by the embodiments of the present invention overcomes the limitations of the current methods by considering the characteristics of significant pressure change, short production start-up time and phase change during the development process of shale oil in China. By using the coupling analysis of pressure and production to predict the ultimate oil production of volume-fractured wells in shale oil, the accuracy of cumulative oil production prediction can be improved, the analysis time can be shortened, the prediction difficulty can be reduced, and a basis can be provided for the production effect evaluation and development plan formulation of volume-fractured wells in shale oil reservoirs.

[0102] Figure 6 This is a schematic structural diagram of a prediction device for the ultimate recovery (EUR) of a shale oil volume fracturing well provided by an embodiment of the present invention. The device can be configured in an electronic device for predicting the ultimate recovery (EUR) of a shale oil volume fracturing well, such as Figure 6 shown, the device includes:

[0103] A unit flow pressure drop oil production determination module 310, configured to determine the first unit flow pressure drop oil production of a standard period within a first preset time period of a shale oil volume fracturing well, and the second unit flow pressure drop oil production of a standard period within a second preset time period of the shale oil volume fracturing well;

[0104] A target decline analysis model determination module 320, configured to analyze the first unit flow pressure drop oil production and the second unit flow pressure drop oil production by using at least one decline analysis method to determine a target decline analysis model;

[0105] A unit flow pressure drop oil production prediction result determination module 330, configured to determine a prediction result of the unit flow pressure drop oil production of a shale oil volume fracturing well within a third preset time period based on the target decline analysis model;

[0106] A predicted production capacity determination module 340, configured to determine the predicted production capacity of a shale oil volume fracturing well within a third preset time period according to the prediction result of the unit flow pressure drop oil production and the predicted bottom-hole flowing pressure result within the third preset time period; wherein, the predicted bottom-hole flowing pressure result is predicted based on the bottom-hole flowing pressure data within the first preset time period and the bottom-hole flowing pressure data within the second preset time period.

[0107] Optionally, the process of determining the predicted bottom-hole flowing pressure result includes: determining the bottom-hole flowing pressure data of a standard period within the first preset time period and the bottom-hole flowing pressure data of a standard period within the second preset time period; analyzing each of the bottom-hole flowing pressure data by using a non-linear regression method to determine a flowing pressure change model; and determining the predicted bottom-hole flowing pressure result within the third preset time period based on the flowing pressure change model.

[0108] Optionally, the target decline analysis model determination module 320 includes a candidate decline analysis model determination unit for analyzing the oil production per unit flow pressure drop of the first unit flow to determine at least one candidate decline analysis model by using at least one decline analysis method; a predicted oil production per unit flow pressure drop determination unit for respectively determining the predicted oil production per unit flow pressure drop of the standard time period within the second preset time period based on each candidate decline analysis model; an oil production per unit flow pressure drop total determination unit for determining the total oil production per unit flow pressure drop of the second unit within the standard time period of the second preset time period, and determining the total oil production per unit flow pressure drop of the standard time period predicted by each candidate decline analysis model within the second preset time period; a target decline analysis model determination unit for determining the target decline analysis model according to the difference between the total oil production per unit flow pressure drop of the second unit and the total oil production per unit flow pressure drop of the predicted standard time period.

[0109] Optionally, the predicted production capacity determination module 340 is specifically configured to determine the predicted daily production capacity of the shale oil volume fracturing well within the third preset time period based on the following formula:

[0110] q = δ×(p wfi - p wf );

[0111] where q represents the predicted daily production capacity of the shale oil volume fracturing well within the third preset time period, δ represents the oil production per unit flow pressure drop of the shale oil volume fracturing well per day within the third preset time period; p wfi represents the initial bottom hole flowing pressure, and p wf represents the predicted result of the bottom hole flowing pressure of the shale oil volume fracturing well per day within the third preset time period.

[0112] Optionally, the device further includes a first adjustment module for determining the predicted production capacity of the shale oil volume fracturing well within the third preset time period according to the size relationship between the third preset time period and the preset production life, and / or according to the size relationship between the predicted daily production capacity of the shale oil volume fracturing well within the third preset time period and the preset minimum daily production.

[0113] Optionally, the device further includes a second adjustment module, including a first target time determination unit for determining the first target time when the predicted result of the bottom hole flowing pressure within the third preset time period is less than the bubble point pressure after determining the predicted production capacity of the shale oil volume fracturing well within the third preset time period; a second target time determination unit for determining the second target time when the target decline analysis model enters the boundary control flow within the third preset time period; an adjustment strategy determination unit for determining the adjustment strategy of the predicted daily production capacity of the shale oil volume fracturing well within the third preset time period according to the sequence relationship between the first target time and the second target time.

[0114] The device provided in the above embodiments can execute the prediction method for the ultimate recoverable amount (EUR) of shale oil volume fracturing wells provided in any embodiment of the present invention, and has the corresponding functional modules and beneficial effects for executing the method.

[0115] Figure 7 It is a schematic structural diagram of an electronic device provided in an embodiment of the present invention. As Figure 7 shown, the device includes:

[0116] One or more processors 410, Figure 7 Taking one processor 410 as an example;

[0117] A memory 420;

[0118] The device may further include: an input device 430 and an output device 440.

[0119] The processor 410, the memory 420, the input device 430, and the output device 440 in the device may be connected through a bus or other means. Figure 7 Taking the connection through the bus as an example.

[0120] The memory 420, as a non-transitory computer-readable storage medium, can be used to store software programs, computer-executable programs, and modules, such as the program instructions / modules corresponding to a prediction method for the ultimate recoverable amount (EUR) of shale oil volume fracturing wells in an embodiment of the present invention. The processor 410 executes various functional applications and data processing of the computer device by running the software programs, instructions, and modules stored in the memory 420, that is, to implement a prediction method for the ultimate recoverable amount (EUR) of shale oil volume fracturing wells in the above method embodiment, that is:

[0121] Determine the oil production per unit flow pressure drop in the standard period of the shale oil volume fracturing well in the first preset time period, and the oil production per unit flow pressure drop in the standard period of the shale oil volume fracturing well in the second preset time period;

[0122] Analyze the oil production per unit flow pressure drop and the oil production per unit flow pressure drop by using at least one decline analysis method to determine the target decline analysis model;

[0123] Based on the target decline analysis model, determine the prediction result of the oil production per unit flow pressure drop of the shale oil volume fracturing well in the third preset time period;

[0124] Determine the predicted production capacity of the shale oil volume fracturing well in the third preset time period according to the predicted oil production volume per unit flow pressure drop and the predicted bottom-hole flowing pressure in the third preset time period; wherein, the predicted bottom-hole flowing pressure result is predicted based on the bottom-hole flowing pressure data in the first preset time period and the bottom-hole flowing pressure data in the second preset time period.

[0125] The memory 420 may include a program storage area and a data storage area. Among them, the program storage area can store an operating system and application programs required for at least one function; the data storage area can store data created according to the use of the computer device. In addition, the memory 420 may include high-speed random access memory, and may also include non-transitory memory, such as at least one disk storage device, a flash memory device, or other non-transitory solid-state storage devices. In some embodiments, the memory 420 may optionally include a memory remotely provided with respect to the processor 410, and these remote memories can be connected to the terminal device 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.

[0126] The input device 430 can be used to receive input digital or character information, and generate key signal inputs related to the user settings and function controls of the computer device. The output device 440 may include a display device such as a display screen.

[0127] An embodiment of the present invention provides a computer-readable storage medium, on which a computer program is stored. When the program is executed by a processor, it implements a method for predicting the ultimate recovery (EUR) of a shale oil volume fracturing well provided by the embodiment of the present invention, that is:

[0128] Determine the oil production volume per unit flow pressure drop in the standard period of the first preset time period of the shale oil volume fracturing well, and the oil production volume per unit flow pressure drop in the standard period of the second preset time period of the shale oil volume fracturing well;

[0129] Analyze the first oil production volume per unit flow pressure drop and the second oil production volume per unit flow pressure drop by using at least one decline analysis method to determine the target decline analysis model;

[0130] Determine the predicted oil production volume per unit flow pressure drop of the shale oil volume fracturing well in the third preset time period based on the target decline analysis model;

[0131] Determine the predicted production capacity of the shale oil volume fracturing well in the third preset time period according to the predicted oil production volume per unit flow pressure drop and the predicted bottom-hole flowing pressure in the third preset time period; wherein, the predicted bottom-hole flowing pressure result is predicted based on the bottom-hole flowing pressure data in the first preset time period and the bottom-hole flowing pressure data in the second preset time period.

[0132] Any combination of one or more computer-readable media may be employed. The computer-readable media may be a computer-readable signal medium or a computer-readable storage medium. A computer-readable storage medium may be, for example, but not limited to, an electrical, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus, or device, or any combination of the foregoing. More specific examples (a non-exhaustive list) of the computer-readable storage medium include: an electrical connection having one or more wires, a portable computer diskette, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or Flash memory), an optical fiber, a portable compact disc read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination of the foregoing. In the present document, a computer-readable storage medium may be any tangible medium that contains or stores a program that can be used by or in connection with an instruction execution system, apparatus, or device.

[0133] A computer-readable signal medium may include a data signal propagated in a baseband or as part of a carrier wave, in which the computer-readable program code is carried. Such a propagated data signal may take many forms, including - but not limited to - an electromagnetic signal, an optical signal, or any suitable combination of the foregoing. A computer-readable signal medium may also be any computer-readable medium other than a computer-readable storage medium that can send, propagate, or transmit a program for use by or in connection with an instruction execution system, apparatus, or device.

[0134] The program code contained on the computer-readable medium may be transmitted using any appropriate medium, including - but not limited to - wireless, wireline, optical fiber cable, RF, etc., or any suitable combination of the foregoing.

[0135] The computer program code for performing the operations of the present invention may be written in one or more programming languages or combinations thereof, including object-oriented programming languages - such as Java, Smalltalk, C++ - and also including conventional procedural programming languages - such as the "C" language or similar programming languages. The program code may execute entirely on the user's computer, partly on the user's computer, as a stand-alone software package, partly on the user's computer and partly on a remote computer, or entirely on the remote computer or server. In the case of a remote computer, the remote computer may be connected to the user's computer through any type of network - including a local area network (LAN) or a wide area network (WAN) - or, alternatively, may be connected to an external computer (e.g., through the Internet using an Internet service provider).

[0136] Note that the above is only a preferred embodiment of the present invention and the technical principles applied. Those skilled in the art will understand that the present invention is not limited to the specific embodiments described herein, and various obvious changes, re-adjustments, and substitutions can be made by those skilled in the art without departing from the protection scope of the present invention. Therefore, although the present invention has been described in more detail through the above embodiments, the present invention is not limited to the above embodiments. Without departing from the concept of the present invention, more other equivalent embodiments can be included, and the scope of the present invention is determined by the scope of the appended claims.

Claims

1. A prediction method for the ultimate recovery (EUR) of a shale oil volume fracturing well, characterized in that, Including: Determine the oil production per unit flowing pressure drop in the standard period of the shale oil volume fracturing well in the first preset time period, and the oil production per unit flowing pressure drop in the standard period of the shale oil volume fracturing well in the second preset time period; Analyze the oil production per unit flowing pressure drop by using at least one decline analysis method to determine at least one candidate decline analysis model; Based on each candidate decline analysis model, respectively determine the predicted oil production per unit flowing pressure drop in the standard period of the second preset time period; Determine the total oil production per unit flowing pressure drop in the standard period of the second preset time period, and determine the total oil production per unit flowing pressure drop in the standard period predicted by each candidate decline analysis model in the second preset time period; Determine the target decline analysis model according to the difference between the total oil production per unit flowing pressure drop and the total predicted oil production per unit flowing pressure drop in the standard period; Based on the target decline analysis model, determine the predicted result of the oil production per unit flowing pressure drop of the shale oil volume fracturing well in the third preset time period; According to the predicted result of the oil production per unit flowing pressure drop and the predicted bottom-hole flowing pressure result in the third preset time period, determine the predicted productivity of the shale oil volume fracturing well in the third preset time period; wherein, the predicted bottom-hole flowing pressure result is predicted based on the bottom-hole flowing pressure data in the first preset time period and the bottom-hole flowing pressure data in the second preset time period; Determine the first target time when the predicted bottom-hole flowing pressure result in the third preset time period is less than the bubble point pressure; Determine the second target time when the target decline analysis model enters the boundary control flow in the third preset time period; Determine the adjustment strategy of the predicted daily productivity of the shale oil volume fracturing well in the third preset time period according to the sequence relationship between the first target time and the second target time; The adjustment strategy is specifically as follows: If the first target time is earlier than the second target time, it means that the shale oil volume fracturing well is in the linear flow stage, and the following formula is used to adjust the predicted daily productivity of the shale oil volume fracturing well in the time period after the bottom-hole flowing pressure is less than the bubble point pressure in the third preset time period: where q o-t-l represents the daily oil production after degassing in the linear flow stage; q o-s-l represents the daily oil production before degassing in the linear flow stage, that is, the daily oil production predicted according to the oil production prediction result of unit flow pressure drop and the bottom hole flowing pressure prediction result within the third preset time period; k o-t represents the effective permeability of the oil phase after degassing; k o-s represents the effective permeability of the oil phase before degassing; μ o-t represents the viscosity of the crude oil after degassing; μ o-s represents the viscosity of the crude oil before degassing; If the first target time is later than the second target time, it means that the shale oil volume fracturing well enters the boundary control flow stage, and the following formula is used to adjust the predicted daily productivity of the shale oil volume fracturing well in the time period after the bottom-hole flowing pressure is less than the bubble point pressure in the third preset time period: Among them, q o-t-b represents the daily oil production after degassing in the boundary control flow stage; q o-s-b represents the daily oil production before degassing in the boundary control flow stage, that is, the daily oil production predicted according to the oil production prediction result of the unit flow pressure drop and the bottom hole flow pressure prediction result within the third preset time period.

2. The method according to claim 1, characterized in that The determination process of the predicted bottom-hole flowing pressure result includes: Determine the bottom-hole flowing pressure data in the standard period of the first preset time period and the bottom-hole flowing pressure data in the standard period of the second preset time period; Analyze each bottom-hole flowing pressure data by using the non-linear regression method to determine the flowing pressure change model; Based on the flowing pressure change model, determine the predicted bottom-hole flowing pressure result in the third preset time period.

3. The method according to claim 2, wherein The determination process of the bottom-hole flowing pressure data in the standard period includes: Process the wellhead pressure data every day in the first preset time period and the second preset time period based on the wellbore multiphase flow calculation method to determine the bottom-hole flowing pressure data every day.

4. The method according to claim 1, characterized in that, Determine the predicted production capacity of the shale oil volume fracturing well in the third preset time period according to the predicted oil production per unit flow pressure drop and the predicted bottom-hole flowing pressure in the third preset time period, including: Determine the predicted daily production capacity of the shale oil volume fracturing well in the third preset time period based on the following formula: q = δ×(p wfi - p wf ); Among them, q represents the predicted daily production capacity of the shale oil volume fracturing well in the third preset time period, δ represents the daily oil production per unit flow pressure drop of the shale oil volume fracturing well in the third preset time period; p wfi represents the initial bottom-hole flowing pressure, p wf represents the predicted result of the bottom-hole flowing pressure of the shale oil volume fracturing well every day in the third preset time period.

5. The method according to claim 4, characterized in that The method further includes: Determine the predicted production capacity of the shale oil volume fracturing well in the third preset time period according to the magnitude relationship between the third preset time period and the preset production life, and / or according to the magnitude relationship between the predicted daily production capacity of the shale oil volume fracturing well in the third preset time period and the preset minimum daily production.

6. A prediction device for the ultimate recovery (EUR) of a shale oil volume fracturing well, characterized in that, Including: A unit flow pressure drop oil production determination module, configured to determine the first unit flow pressure drop oil production in the standard time period of the shale oil volume fracturing well in the first preset time period, and the second unit flow pressure drop oil production in the standard time period of the shale oil volume fracturing well in the second preset time period; A target decline analysis model determination module, configured to analyze the first unit flow pressure drop oil production and the second unit flow pressure drop oil production by using at least one decline analysis method to determine a target decline analysis model; A predicted result determination module for unit flow pressure drop oil production, configured to determine the predicted result of the unit flow pressure drop oil production of the shale oil volume fracturing well in the third preset time period based on the target decline analysis model; A predicted production capacity determination module, configured to determine the predicted production capacity of the shale oil volume fracturing well in the third preset time period according to the predicted result of the unit flow pressure drop oil production and the predicted bottom-hole flowing pressure in the third preset time period; wherein, the predicted bottom-hole flowing pressure result is predicted based on the bottom-hole flowing pressure data in the first preset time period and the bottom-hole flowing pressure data in the second preset time period; The target decline analysis model determination module includes a candidate decline analysis model determination unit, configured to analyze the first unit flow pressure drop oil production by using at least one decline analysis method to determine at least one candidate decline analysis model; a predicted unit flow pressure drop oil production determination unit, configured to respectively determine the predicted unit flow pressure drop oil production in the standard time period of the second preset time period based on each candidate decline analysis model; a total unit flow pressure drop oil production determination unit, configured to determine the total second unit flow pressure drop oil production in the standard time period of the second preset time period, and determine the total unit flow pressure drop oil production in the standard time period predicted by each candidate decline analysis model in the second preset time period; a target decline analysis model determination unit, configured to determine the target decline analysis model according to the difference between the total second unit flow pressure drop oil production and the total predicted unit flow pressure drop oil production in the standard time period; The device further includes a second adjustment module, which includes a first target time determination unit for determining a first target time when the predicted bottom-hole flowing pressure in a third preset time period is less than the bubble point pressure after determining the predicted production capacity of the shale oil volumetric fracturing well in the third preset time period; a second target time determination unit for determining a second target time when the target decline analysis model enters the boundary control flow in the third preset time period; and an adjustment strategy determination unit for determining an adjustment strategy for the predicted daily production capacity of the shale oil volumetric fracturing well in the third preset time period according to the chronological relationship between the first target time and the second target time. The adjustment strategy is specifically as follows: If the first target time is earlier than the second target time, it means that the shale oil volumetric fracturing well is in the linear flow stage, and the following formula is used to adjust the predicted daily production capacity of the shale oil volumetric fracturing well in the time period after the bottom-hole flowing pressure is less than the bubble point pressure in the third preset time period: where q o-t-l represents the daily oil production after degassing in the linear flow stage; q o-s-l represents the daily oil production before degassing in the linear flow stage, that is, the daily oil production predicted according to the oil production prediction result per unit flow pressure drop and the bottom hole flowing pressure prediction result within the third preset time period; k o-t represents the effective permeability of the oil phase after degassing; k o-s represents the effective permeability of the oil phase before degassing; μ o-t represents the viscosity of the crude oil after degassing; μ o-s represents the viscosity of the crude oil before degassing; If the first target time is later than the second target time, it means that the shale oil volumetric fracturing well enters the boundary control flow stage, and the following formula is used to adjust the predicted daily production capacity of the shale oil volumetric fracturing well in the time period after the bottom-hole flowing pressure is less than the bubble point pressure in the third preset time period: Among them, q o-t-b represents the daily oil production after degassing in the boundary control flow stage; q o-s-b represents the daily oil production before degassing in the boundary control flow stage, that is, the daily oil production predicted based on the oil production prediction result of the unit flow pressure drop and the bottom hole flow pressure prediction result within the third preset time period.

7. An electronic device, characterized in that, It includes: One or more processors; A storage device for storing one or more programs, When the one or more programs are executed by the one or more processors, the one or more processors implement the prediction method for the ultimate recovery (EUR) of the shale oil volumetric fracturing well according to any one of claims 1-5.

8. A computer-readable storage medium having a computer program stored thereon, characterized in that, When the program is executed by the processor, it implements the prediction method for the ultimate recovery (EUR) of the shale oil volumetric fracturing well according to any one of claims 1-5.

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