A method and device for predicting recovery rate of crude oil elastic mining

Abstract

The present application is applicable to the technical field of crude oil extraction, and provides a method and device for predicting the recovery rate of crude oil elastic extraction, wherein the method for predicting the recovery rate of crude oil elastic extraction includes: respectively establishing mathematical models of the influence of the effective fluid viscosity and effective permeability of crude oil in the oil well mining area on the recovery rate of crude oil elastic extraction, establishing a mathematical model of the comprehensive influence of the effective permeability and effective fluid viscosity of the oil well mining area on the elastic extraction crude oil, establishing a mathematical model of the total oil production driven by elastic energy in the oil well mining area, establishing a mathematical model of the total crude oil reserves within the oil leakage range of the oil well mining area, and calculating the recovery rate of crude oil elastic extraction according to the total oil production driven by elastic energy in the oil well mining area and the total crude oil reserves within the oil leakage range of the oil well mining area. The method solves the problem that the existing method for predicting the recovery rate of crude oil elastic extraction cannot accurately predict the crude oil output rate and cannot accurately evaluate the economic benefits of the oil field.

Description

Technical Field

[0001] The present application belongs to the technical field of crude oil extraction, and in particular, relates to a method and device for predicting recovery rate of crude oil elastic extraction. Background Art

[0002] With the increasing acceleration of global economic development, oil and gas consumption has gradually increased, and crude oil extraction has become more and more difficult; however, in the tight reservoirs adjacent to high-quality oil-generating strata, there is oil formed by large-scale long-distance migration, which is also called tight oil; more and more researchers have begun to study the extraction of tight oil. With the continuous improvement of oil and gas exploration and development technologies such as volume fracturing and multi-stage fracturing of horizontal wells, the output of tight oil has increased. Among them, the successful development of tight oil reservoirs and their increasing commercialization have had a huge impact on the development of tight oil, making the role of tight oil reservoirs in solving energy needs more and more important.

[0003] However, tight oil is currently mainly developed and utilized through elastic mining, and its recovery rate is low and the remaining oil content is thick. People have done little research on the elastic mining rules of tight oil and its influencing factors, and the recovery rate of crude oil cannot be accurately predicted, and oil fields cannot be developed efficiently.

[0004] In summary, the existing crude oil elastic production recovery rate prediction methods cannot accurately predict the crude oil output rate and cannot accurately evaluate the economic benefits of the oil field. Summary of the invention

[0005] In view of this, the embodiments of the present application provide a crude oil elastic production recovery rate prediction method and prediction device, which can solve the problem that the existing crude oil elastic production recovery rate prediction method cannot accurately predict the crude oil output rate and cannot accurately evaluate the economic benefits of the oil field.

[0006] A first aspect of an embodiment of the present application provides a method for predicting recovery rate of crude oil elastic production, which is applied to an oil well mining area. The method for predicting recovery rate of crude oil elastic production includes:

[0007] Calculate the effective permeability of the oil well mining area based on the permeability at m×n monitoring points The m×n monitoring points are arranged in an array, and each of the monitoring points is located on a plane at H / 2 of the oil well mining area, where H is the thickness of the oil well mining area;

[0008] Calculate the effective fluid viscosity of the oil well mining area according to the fluid viscosity at the m×n monitoring points

[0009] Establishing the effective permeability of the oil well area Mathematical Model of the Impact on the Recovery Factor of Crude Oil Elastic Production for:

[0010]

[0011] Among them, α1 is the exponential component coefficient, α2 is the effective permeability coefficient, α3 is the correction coefficient of the effect of the effective permeability on the elastic recovery of crude oil, P w is the bottom hole pressure of the oil well mining area;

[0012] Establishing the effective fluid viscosity of the oil well field Mathematical Model of the Influence on Elastic Recovery of Crude Oil for:

[0013]

[0014] Where b1 is the effective fluid viscosity Correction coefficient for the elastic production of crude oil, b2 is the cosine component coefficient, b3 is the sine component coefficient, ω1 is the fluid viscosity coefficient, P w is the bottom hole pressure of the oil well mining area;

[0015] Establish the effective permeability of the oil well area and the effective fluid viscosity of the oil well area Mathematical model of comprehensive influence on the elastic production of crude oil for:

[0016]

[0017] Where β1 is the effective permeability of the oil well mining area The proportional coefficient of the comprehensive impact on the elastic exploitation of crude oil, β2 is the effective fluid viscosity of the oil well mining area The proportional coefficient of the comprehensive impact of the elastic exploitation of crude oil, β3 is the correction coefficient of the mathematical model of the comprehensive impact of the elastic exploitation of crude oil;

[0018] Establishing a mathematical model V1 of the total oil production of the oil well mining area driven by elastic energy;

[0019] Establishing a mathematical model V2 of the total crude oil reserves within the oil well mining area;

[0020] Calculate the recovery factor of crude oil elastic production Among them, V1 is the total oil production of the oil well mining area driven by elastic energy, and V2 is the total crude oil reserves within the oil leakage range of the oil well mining area.

[0021] In one embodiment, the effective permeability of the oil well mining area is calculated include:

[0022] The permeability at the m×n monitoring points is measured respectively and expressed by matrix K as:

[0023]

[0024] Among them, k 1i represents the permeability of the oil well mining area at the monitoring point in the i-th column among the n horizontal columns of measuring points and the monitoring point in the first row among the m vertical rows of measuring points, i=1,2,3…,n; k ti represents the permeability of the oil well mining area at the monitoring point in the i-th column among the n horizontal columns of measuring points and the monitoring point in the t-th row among the m vertical rows of measuring points, where t=1, 2, 3…, m;

[0025] The ratio coefficient of the permeability of the transverse n-row measurement points to the effective permeability of the oil well mining area is expressed by the set D as follows:

[0026] D=[d1 d2 … d i …d n ];

[0027] d i represents the ratio coefficient of the permeability at the monitoring point in the i-th column to the effective permeability of the oil well mining area, i = 1, 2, 3..., n;

[0028] The effective permeability of the oil well mining area is for:

[0029]

[0030] In one embodiment, the calculating the effective fluid viscosity of the oil well mining area include:

[0031] The ratio coefficient of the fluid viscosity of the n horizontal rows of measurement points to the effective fluid viscosity of the oil well mining area is expressed by the set P as follows:

[0032] P=[p1 p2 … p i … p n ];

[0033] p i represents the ratio coefficient of the fluid viscosity at the i-th column monitoring point to the effective fluid viscosity of the oil well mining area, where i = 1, 2, 3..., n;

[0034] Then, the effective fluid viscosity of the oil well mining area is for:

[0035]

[0036] In one embodiment, the method for predicting recovery rate of crude oil elastic production further includes:

[0037] The mathematical model for establishing the starting pressure gradient G for elastic exploitation of the oil well mining area is:

[0038]

[0039] In one embodiment, the establishment of the mathematical model V1 of the total oil production of the oil well mining area driven by elastic energy includes:

[0040] Calculate the bottom hole pressure P of the oil well mining area w The effective volume coefficient of crude oil under well pressure

[0041] The mathematical model dΔV1 of oil production driven by elastic energy in the microelement with a length of dx in the oil well mining area is established as follows:

[0042]

[0043] The oil well mining area is X meters long, Y meters wide and H meters thick; i is the formation pressure of the oil well mining area, P w is the bottom hole pressure of the oil well mining area, and G is the starting pressure gradient for elastic mining of the oil well mining area.

[0044] In one embodiment, the establishment of the mathematical model V1 of the total oil production of the oil well mining area driven by elastic energy further includes:

[0045] According to the oil production dΔV1 driven by elastic energy in the microelement with a length of dx in the oil well mining area, a mathematical model V1 of the total oil production driven by elastic energy in the oil well mining area is established:

[0046]

[0047] In one embodiment, the mathematical model V2 for establishing the total crude oil reserves within the oil well mining area leakage range includes:

[0048] The porosity at the m×n monitoring points is measured respectively to calculate the effective porosity of the oil well mining area.

[0049] The irreducible water saturation at the m×n monitoring points is measured respectively, and the effective irreducible water saturation of the oil well mining area is calculated.

[0050] Calculate the effective original pressure volume coefficient of crude oil at the original formation pressure in the oil well mining area

[0051] In one embodiment, the mathematical model V2 for establishing the total crude oil reserves within the oil well mining area leakage range further includes:

[0052] According to the effective porosity of the oil well mining area The effective irreducible water saturation of the oil well mining area and the effective porosity of the oil well mining area The mathematical model V2 for the total crude oil reserves within the oil well mining area is established as:

[0053]

[0054] In one embodiment, the calculation of the elastic recovery factor E of crude oil includes:

[0055] The mathematical model of the crude oil elastic production recovery factor E of the total crude oil reserves V2 and the total oil production V1 driven by elastic energy in the oil well mining area is established as follows:

[0056]

[0057] A second aspect of an embodiment of the present application provides a prediction device, which is used to execute the crude oil elastic production recovery factor prediction method as described in any of the above items.

[0058] The embodiment of the present application provides a method and device for predicting the recovery rate of elastic production of crude oil, wherein the method comprises: establishing a mathematical model of the influence of the effective permeability of the oil well mining area on the recovery rate of elastic production of crude oil, establishing a mathematical model of the influence of the effective fluid viscosity of crude oil in the oil well mining area on the elastic production of crude oil, then establishing a mathematical model of the comprehensive influence of the effective permeability of the oil well mining area and the effective fluid viscosity of crude oil in the oil well mining area on the elastic production of crude oil, establishing a mathematical model of the total oil production driven by elastic energy in the oil well mining area, establishing a mathematical model of the total crude oil reserves within the oil leakage range of the oil well mining area, and calculating the recovery rate of elastic production of crude oil according to the total oil production driven by elastic energy in the oil well mining area and the total crude oil reserves within the oil leakage range of the oil well mining area. The method can solve the problem that the existing method for predicting the recovery rate of elastic production of crude oil cannot accurately predict the crude oil output rate and cannot accurately evaluate the economic benefits of the oil field. BRIEF DESCRIPTION OF THE DRAWINGS

[0059] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0060] Figure 1 This is a schematic diagram of the steps of a method for predicting recovery rate of crude oil elastic production provided by an embodiment of the present application;

[0061] Figure 2 This is a structural schematic diagram of a crude oil elastic production recovery rate monitoring point provided by an embodiment of the present application;

[0062] Figure 3 It is a schematic diagram of actual production and predicted production of a method for predicting recovery rate of crude oil elastic production provided by an embodiment of the present application;

[0063] Figure 4 It is a schematic diagram of the output rate of a crude oil elastic recovery factor prediction method provided by an embodiment of the present application;

[0064] Figure 5 This is a schematic diagram of the number of experiments and errors of a crude oil elastic recovery factor prediction method provided in an embodiment of the present application. DETAILED DESCRIPTION

[0065] In the following description, specific details such as specific system structures, technologies, etc. are provided for the purpose of illustration rather than limitation, so as to provide a thorough understanding of the embodiments of the present application. However, it should be clear to those skilled in the art that the present application may also be implemented in other embodiments without these specific details. In other cases, detailed descriptions of well-known systems, devices, circuits, and methods are omitted to prevent unnecessary details from obstructing the description of the present application.

[0066] The following will be combined with the drawings in the embodiments of the present application to clearly describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0067] With the increasing acceleration of global economic development, oil and gas consumption has gradually increased, and crude oil extraction has become more and more difficult; however, in the tight reservoirs adjacent to high-quality oil-generating strata, there is oil formed by large-scale long-distance migration, which is also called tight oil; more and more researchers have begun to study the extraction of tight oil. With the continuous improvement of oil and gas exploration and development technologies such as volume fracturing and multi-stage fracturing of horizontal wells, the output of tight oil has increased. Among them, the successful development of tight oil reservoirs and their increasing commercialization have had a huge impact on the development of tight oil, making the role of tight oil reservoirs in solving energy needs more and more important.

[0068] However, tight oil is currently mainly developed and utilized through elastic mining, with low recovery rate and high residual oil content. People have conducted little research on the elastic mining laws of tight oil and its influencing factors, and the crude oil recovery rate cannot be accurately predicted, and the oil fields cannot be developed efficiently. The existing crude oil elastic mining recovery rate prediction methods cannot accurately predict the crude oil output rate and cannot accurately evaluate the economic benefits of the oil fields.

[0069] In order to solve the above technical problems, the present application embodiment provides a method for predicting the recovery rate of crude oil elastic production, referring to Figure 1 , Figure 2 As shown, the method for predicting the recovery rate of crude oil elastic production includes: steps S100 to S800.

[0070] In step S100, the effective permeability of the oil well mining area is calculated based on the permeability at m×n monitoring points. Among them, m×n monitoring points are arranged in an array, and each monitoring point is located in the plane at H / 2 of the oil well mining area, and H is the thickness of the oil well mining area.

[0071] In step S200, the effective fluid viscosity of crude oil in the oil well mining area is calculated according to the viscosity of crude oil fluid at m×n monitoring points.

[0072] In step S300, the effective permeability of the oil well mining area is established Mathematical Model of the Impact on the Recovery Factor of Crude Oil Elastic Production for:

[0073]

[0074] Among them, α1 is the exponential component coefficient, α2 is the effective permeability coefficient, α3 is the correction coefficient of the effect of effective permeability on the elastic recovery of crude oil, P w is the bottom hole pressure in the oil well mining area;

[0075] In step S400, the effective fluid viscosity of crude oil in the oil well mining area is established. Mathematical Model of the Influence on Elastic Recovery of Crude Oil for:

[0076]

[0077] Where b1 is the effective fluid viscosity of crude oil Correction coefficient for the elastic recovery of crude oil, b2 is the cosine component coefficient, b3 is the sine component coefficient, ω1 is the viscosity coefficient of crude oil fluid, P w It is the bottom hole pressure of the oil well mining area.

[0078] In step S500, the effective permeability of the oil well mining area is established and the effective fluid viscosity of crude oil in the oil well mining area Mathematical Model of Comprehensive Influence on Elastic Recovery of Crude Oil for:

[0079]

[0080] Among them, β1 is the effective permeability of the oil well mining area The proportional coefficient of the comprehensive impact on elastic recovery of crude oil, β2 is the effective fluid viscosity of crude oil in the oil well mining area The proportional coefficient of the comprehensive impact on elastic crude oil exploitation, β3 is the correction coefficient of the mathematical model of the comprehensive impact of elastic crude oil exploitation.

[0081] In step S600, a mathematical model V1 of the total oil production of an oil well mining area driven by elastic energy is established.

[0082] In step S700, a mathematical model V2 of the total crude oil reserves within the oil well mining area is established.

[0083] In step S800, the elastic recovery factor of crude oil is calculated. Among them, V1 is the total oil production of the oil well mining area driven by elastic energy, and V2 is the total crude oil reserves within the oil leakage range of the oil well mining area.

[0084] In this embodiment, in the oil well mining area, n columns of measuring points are selected horizontally with a first spacing, and m columns of measuring points are selected vertically with a second spacing from the selected n columns of measuring points, and a total of m×n monitoring points are selected; wherein m and n are both positive integers, the length of the oil well mining area is X meters, the width is Y meters, and the thickness is H meters, and the m×n monitoring points are all located in the plane at H / 2 of the oil well mining area, wherein the distances of the first spacing and the second spacing may be the same or different. Selecting m×n monitoring points and the positions of the m×n monitoring points being located in the middle of the thickness of the oil well mining area can make the measured data of the monitoring points close to the average value of the entire oil well mining area to the maximum extent. Compared with measuring the monitoring data at the boundary position of the oil well mining area, the final calculation result will be more accurate and closer to the real value of the real oil well mining area, which can make the calculation of crude oil output rate more accurate and can more accurately evaluate the economic benefits of the oil field.

[0085] In this embodiment, the permeability at m×n monitoring points is measured respectively to calculate the effective permeability of the oil well mining area. Measure the viscosity of crude oil fluid at m×n monitoring points respectively and calculate the effective viscosity of crude oil fluid in the oil well mining area Because in the process of elastic extraction of crude oil, the viscosity and permeability of crude oil fluid have an important influence on the elastic extraction of crude oil. The viscosity and permeability of crude oil fluid in different oil well mining areas are different, so the crude oil recovery rate is also different. Only by accurately measuring the viscosity and permeability of crude oil fluid in oil well mining areas can the crude oil recovery rate be accurately calculated.

[0086] In this example, the effective permeability of the oil well mining area is established. Mathematical Model of the Impact on the Recovery Factor of Crude Oil Elastic Production for:

[0087]

[0088] Among them, α1 is the exponential component coefficient, α2 is the effective permeability coefficient, α3 is the correction coefficient of the effect of effective permeability on the elastic recovery of crude oil, P w is the bottom hole pressure in the oil well mining area;

[0089] In this embodiment, by establishing a mathematical model of the effect of effective permeability on the elastic recovery of crude oil, in one experiment, the effective permeabilities of eight oil wells were calculated and measured according to the control variable method, and were 0.02×10 -3 μm 2 , 0.04×10 -3 μm 2 , 0.06×10 -3 μm 2 , 0.08×10 -3 μm 2 , 0.1×10 -3 μm 2 , 0.12×10 -3 μm 2 , 0.14×10 -3 μm 2 , 0.16×10 -3 μm 2 Under the following conditions, the effects of effective permeability on the elastic recovery factor of crude oil are 0.121, 0.126, 0.128, 0.130, 0.132, 0.133, 0.134 and 0.135 respectively.

[0090] Bringing it into the mathematical model In the calculation, we get:

[0091]

[0092] but, Specifically, establish the effective permeability of the oil well mining area The mathematical model that affects the recovery rate of crude oil elastic production can make the calculation of crude oil output rate more accurate and can more accurately evaluate the economic benefits of oil fields.

[0093] In this embodiment, the effective fluid viscosity of crude oil in the oil well mining area is established. Mathematical Model of the Influence on Elastic Recovery of Crude Oil for:

[0094]

[0095] Where b1 is the effective fluid viscosity of crude oil Correction coefficient for the elastic recovery of crude oil, b2 is the cosine component coefficient, b3 is the sine component coefficient, ω1 is the viscosity coefficient of crude oil fluid, P w is the bottom hole pressure in the oil well mining area;

[0096] In this embodiment, the effective fluid viscosity of crude oil in the oil well mining area is established. Mathematical model of the influence of elastic exploitation of crude oil. In an experiment, the effective fluid viscosity of crude oil in five oil well mining areas was measured and calculated according to the control variable method. The effective fluid viscosity had an influence on the elastic exploitation recovery rate of crude oil of 0.122, 0.108, 0.097, 0.090 and 0.085 respectively. The viscosity was put into the mathematical model. In the calculation, we get:

[0097]

[0098] Then, the effective fluid viscosity of crude oil in the oil well mining area is Mathematical Model of the Influence on Elastic Recovery of Crude Oil for:

[0099]

[0100] Specifically, establish the effective fluid viscosity of crude oil in the oil well mining area The mathematical model of the impact of elastic crude oil production can make the calculation of crude oil output rate more accurate and can more accurately evaluate the economic benefits of the oil field.

[0101] In this embodiment, the elastic production recovery factor E of crude oil is calculated based on the total oil production V1 driven by elastic energy in the oil well mining area and the total crude oil reserves V2 within the oil leakage range of the oil well mining area.

[0102] Specifically, by calculating the ratio of the total oil production driven by elastic energy in the oil well mining area to the total crude oil reserves within the oil well mining area's oil leakage range, the crude oil elastic mining recovery rate can be accurately calculated, thereby solving the problem that the existing crude oil elastic mining recovery rate prediction method cannot accurately predict the crude oil output rate and cannot accurately evaluate the economic benefits of the oil field.

[0103] In one embodiment, in step S100, the effective permeability of the oil well mining area is calculated. include:

[0104] The permeability at m×n monitoring points is measured separately and expressed by matrix K as:

[0105]

[0106] Among them, k 1i represents the permeability of the oil well mining area at the monitoring point in the i-th column among the n horizontal columns of measuring points and the monitoring point in the first row among the m vertical rows of measuring points, i = 1, 2, 3…, n; k ti represents the permeability of the oil well mining area at the monitoring point in the i-th column among the n-column measuring points in the horizontal direction and the monitoring point in the t-th row among the m-row measuring points in the vertical direction, where t = 1, 2, 3…, m;

[0107] The oil well mining area is unevenly distributed underground, resulting in inconsistent permeability at different monitoring points. The ratio coefficient of the permeability of the n horizontal columns of measurement points to the effective permeability of the oil well mining area is expressed by the set D as:

[0108] D=[d1 d2 … d i …d n ];

[0109] d i It represents the ratio coefficient of the permeability at the monitoring point in the ith column among the n columns of measurement points in the horizontal direction to the effective permeability of the oil well mining area, i=1,2,3…,n.

[0110] The effective permeability of the oil well mining area is for:

[0111]

[0112] In this embodiment, in the oil well mining area, n columns of measuring points are selected horizontally at a first spacing, and m columns of measuring points are selected vertically at a second spacing among the selected n columns of measuring points, and a total of m×n monitoring points are selected; wherein m and n are both positive integers, the length of the oil well mining area is X meters, the width is Y meters, and the thickness is H meters, and the m×n monitoring points are all located in a plane at H / 2 of the oil well mining area; by setting the proportional coefficient of the permeability at the n horizontal measuring points, the effective permeability of the oil well mining area can be measured more accurately.

[0113] In this embodiment, the proportional coefficient of the permeability at the n horizontal columns of measurement points can be set in advance according to different oil well mining areas using a set D. For example, it can be calculated based on the proportion of the permeability at the n horizontal columns of measurement points to the average permeability of the oil well mining area.

[0114] In one embodiment, in step S200, the effective fluid viscosity of the oil well mining area is calculated include:

[0115] The oil well mining area is extremely unevenly distributed underground, resulting in different fluid viscosities at different monitoring points. The ratio coefficient of the fluid viscosity at the n horizontal columns of measurement points to the effective fluid viscosity of the oil well mining area is expressed by the set P as follows:

[0116] P=[p1 p2 … p i … p n ];

[0117] p i represents the ratio coefficient of the fluid viscosity at the i-th column of the measuring points in the horizontal n columns to the effective fluid viscosity of the oil well mining area, where i=1,2,3…,n;

[0118] Then, the effective fluid viscosity in the oil well mining area is for:

[0119]

[0120] In this implementation, the fluid viscosity at m×n monitoring points is measured respectively, and a set of proportional coefficients of the fluid viscosity at the horizontal n measuring points is established, and then the effective fluid viscosity of the oil well mining area is calculated.

[0121] In one embodiment, the method for predicting the recovery rate of crude oil elastic production further includes:

[0122] The mathematical model for establishing the starting pressure gradient G of the elastic production oil well mining area is:

[0123]

[0124] In this embodiment, different starting pressure gradients have different effects on the elastic recovery rate of crude oil. By establishing a mathematical model of the starting pressure gradient G, the elastic recovery rate of crude oil can be accurately calculated, thereby solving the problem that the existing elastic recovery rate prediction method of crude oil cannot accurately predict the crude oil output rate and cannot accurately evaluate the economic benefits of the oil field.

[0125] In one embodiment, in step S600, establishing a mathematical model V1 of total oil production in an oil well mining area driven by elastic energy includes steps S610-S630:

[0126] In step S610, the bottom hole pressure P of the oil well mining area is calculated. w The effective volume coefficient of crude oil under well pressure

[0127] In step S620, a mathematical model dΔV1 of oil production driven by elastic energy in a microelement with a length of dx in the oil well mining area is established:

[0128]

[0129] The length of the oil well mining area is X meters, the width is Y meters, and the thickness is H meters; i is the formation pressure in the oil well mining area, P w is the bottom hole pressure of the oil well mining area, and G is the starting pressure gradient of the oil well mining area for elastic production.

[0130] In this embodiment, by calculating the oil production dΔV1 driven by elastic energy in a microelement with a length of dx in the oil well mining area, preparation is made for the subsequent calculation of the total oil production driven by elastic energy in the oil well mining area.

[0131] In this embodiment, the oil well mining area is at the bottom hole pressure P w The effective volume coefficient of crude oil under well pressure The method can be used to calculate the bottom hole pressure P of the oil well mining area in the microelement with a length of dx. w The volume coefficient of crude oil under the condition of C1 is calculated, and then the effective well pressure volume coefficient of the oil well mining area is calculated by integration. Specifically,

[0132]

[0133] In one embodiment, establishing a mathematical model V1 of total oil production in an oil well mining area driven by elastic energy further includes:

[0134] In step S630, a mathematical model V1 of the total oil production of the oil well mining area driven by elastic energy is established according to the oil production dΔV1 driven by elastic energy in the microelement with a length of dx of the oil well mining area:

[0135]

[0136] In one embodiment, in step S700, establishing a mathematical model V2 of the total crude oil reserves within the oil well mining area leakage range includes steps S710-S740.

[0137] In step S710, the porosity at m×n monitoring points is measured respectively to calculate the effective porosity of the oil well mining area.

[0138] In step S720, the irreducible water saturation at m×n monitoring points is measured respectively to calculate the effective irreducible water saturation of the oil well mining area.

[0139] In step S730, the effective original pressure volume coefficient of crude oil in the oil well mining area under the original formation pressure is calculated.

[0140] In this example, the effective porosity of the oil well mining area is calculated. and calculate the effective irreducible water saturation of the oil well area Method and calculation of effective fluid viscosity of crude oil in oil well mining area The method is the same as that of calculating the effective original pressure volume coefficient of crude oil at the original formation pressure in the oil well mining area Method and calculation of oil well bottom pressure P w The effective volume coefficient of crude oil under well pressure The method is the same.

[0141] In one embodiment, the effective porosity of the oil well area is Effective irreducible water saturation in oil well mining areas Crude oil effective fluid viscosity Effective penetration Crude oil effective original pressure volume coefficient Bottom hole pressure P w The effective volume coefficient of crude oil under well pressure These values ​​can also be calculated by averaging.

[0142] In one embodiment, the mathematical model V2 for establishing the total crude oil reserves within the oil well mining area leakage range further includes:

[0143] In step S740, according to the effective porosity of the oil well mining area Effective irreducible water saturation in oil well mining areas and the effective porosity of the oil well area The mathematical model V2 for the total crude oil reserves within the oil well area leakage range is established as:

[0144]

[0145] In one embodiment, in step S800, calculating the elastic production recovery factor E of crude oil includes:

[0146] The mathematical model of the elastic recovery factor E of crude oil with total crude oil reserves V2 and total oil production V1 driven by elastic energy in the oil well mining area is established as follows:

[0147]

[0148] In one embodiment, reference Figure 3 As shown, the present invention is applied to different oil well mining areas, and the crude oil production of different oil well mining areas is measured using the patented method. The measurement results are as follows Figure 3 As shown in the figure, it can be seen that the output of this capacity prediction method at oil mines 1-6 differs from the actual output by 4,800 tons, 3,600 tons, 4,000 tons, 2,200 tons, 6,300 tons and 3,200 tons respectively, with the maximum difference being 6,300 tons. The relative measurement accuracy is 1.83%, which is 5.00% higher than the industrial requirement and meets industrial needs.

[0149] In one embodiment, reference Figure 4 As shown, the present invention is applied to different oil well mining areas, and the crude oil output rate, actual output rate and output rate calculated by the existing method in different oil well mining areas are measured by the patent method. The measurement results are shown in FIG. Figure 4 As shown in the figure, it can be seen that the output rate prediction method of the present invention at oil mines 1-12 has a high relative measurement accuracy compared with the output rate calculated by the existing method, which is 5.00% higher than the industrial required accuracy and meets industrial needs.

[0150] In one embodiment, Figure 5 As shown, 20 experiments on elastic recovery rate prediction of crude oil were carried out in different oil well mining areas using the patented method. It can be seen from the figure that the average error value of elastic recovery rate of crude oil is 0.98%, the variance is 2, and the maximum error is 1.21%, so the patented method is stable. 20 experiments on elastic recovery rate prediction of crude oil were carried out in different oil well mining areas using the patented method, and the average value was recorded as the result. It can be seen that the maximum relative error is 1.18, which meets industrial needs.

[0151] An embodiment of the present application also provides a prediction device, which is used to execute the crude oil elastic production recovery rate prediction method as described in any of the above items.

[0152] In the above embodiments, the description of each embodiment has its own emphasis. For parts that are not described or recorded in detail in a certain embodiment, reference can be made to the relevant descriptions of other embodiments.

[0153] The above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them. Although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. These modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present application, and should all be included in the protection scope of the present application.

Claims

1. A method for predicting the recovery rate of crude oil elastic mining, applied to oil well mining areas, characterized in that: The crude oil elastic production recovery factor prediction method comprises: Calculate the effective permeability of the oil well mining area based on the permeability at m×n monitoring points The m×n monitoring points are arranged in an array, and each of the monitoring points is located on a plane at H / 2 of the oil well mining area, where H is the thickness of the oil well mining area; Calculate the effective fluid viscosity of the oil well mining area according to the fluid viscosity at the m×n monitoring points Establishing the effective permeability of the oil well area Mathematical Model of the Impact on the Recovery Factor of Crude Oil Elastic Production for: Among them, α1 is the exponential component coefficient, α2 is the effective permeability coefficient, α3 is the correction coefficient of the effect of the effective permeability on the elastic recovery of crude oil, P w is the bottom hole pressure of the oil well mining area; Establishing the effective fluid viscosity of the oil well field Mathematical Model of the Influence on Elastic Recovery of Crude Oil for: Where b1 is the effective fluid viscosity Correction coefficient for the elastic production of crude oil, b2 is the cosine component coefficient, b3 is the sine component coefficient, ω1 is the fluid viscosity coefficient, P w is the bottom hole pressure of the oil well mining area; Establish the effective permeability of the oil well area and the effective fluid viscosity of the oil well area Mathematical model of comprehensive influence on the elastic production of crude oil for: Where β1 is the effective permeability of the oil well mining area The proportional coefficient of the comprehensive impact on the elastic exploitation of crude oil, β2 is the effective fluid viscosity of the oil well mining area The proportional coefficient of the comprehensive impact on the elastic exploitation of crude oil, β3 is the correction coefficient of the mathematical model of the comprehensive impact on the elastic exploitation of crude oil; Establishing a mathematical model V1 of the total oil production of the oil well mining area driven by elastic energy; Establishing a mathematical model V2 of the total crude oil reserves within the oil well mining area; Calculate the recovery factor of crude oil elastic production Among them, V1 is the total oil production of the oil well mining area driven by elastic energy, and V2 is the total crude oil reserves within the oil leakage range of the oil well mining area.

2. The method for predicting the recovery rate of crude oil elastic production according to claim 1, characterized in that: The effective permeability of the oil well mining area is calculated include: The permeability at the m×n monitoring points is measured respectively and expressed by matrix K as: Among them, k 1i represents the permeability of the oil well mining area at the monitoring point in the i-th column among the n horizontal columns of measuring points and the monitoring point in the first row among the m vertical rows of measuring points, i=1,2,3…,n; k ti represents the permeability of the oil well mining area at the monitoring point in the i-th column among the n horizontal columns of measuring points and the monitoring point in the t-th row among the m vertical rows of measuring points, where t=1, 2, 3…, m; The ratio coefficient of the permeability of the transverse n-row measurement points to the effective permeability of the oil well mining area is expressed by the set D as follows: D=[d1 d2 … d i … d n ]; Among them, d i represents the ratio coefficient of the permeability at the monitoring point in the i-th column to the effective permeability of the oil well mining area, i = 1, 2, 3..., n; Then, the effective permeability of the oil well mining area is for:

3. The method for predicting the recovery rate of crude oil elastic production according to claim 2, characterized in that: The calculation of the effective fluid viscosity of the oil well mining area include: The ratio coefficient of the fluid viscosity of the n horizontal rows of measurement points to the effective fluid viscosity of the oil well mining area is expressed by the set P as follows: P=[p1 p2 … p i … p n ]; p i represents the ratio coefficient of the fluid viscosity at the i-th column monitoring point to the effective fluid viscosity of the oil well mining area, where i = 1, 2, 3..., n; Then, the effective fluid viscosity of the oil well mining area is for:

4. The method for predicting the recovery rate of crude oil elastic production according to claim 3, characterized in that: The crude oil elastic production recovery factor prediction method also includes: The mathematical model for establishing the starting pressure gradient G for elastic exploitation of the oil well mining area is:

5. The method for predicting recovery rate of crude oil elastic production according to claim 4, characterized in that: The mathematical model V1 of total oil production of the oil well mining area driven by elastic energy includes: Calculate the bottom hole pressure P of the oil well mining area w The effective volume coefficient of crude oil under well pressure The mathematical model dΔV1 of oil production driven by elastic energy in the microelement with a length of dx in the oil well mining area is established as follows: The oil well mining area is X meters long, Y meters wide and H meters thick; i is the formation pressure of the oil well mining area, P w is the bottom hole pressure of the oil well mining area, and G is the starting pressure gradient for elastic mining of the oil well mining area.

6. The method for predicting recovery rate of crude oil elastic production according to claim 5, characterized in that: The mathematical model V1 for the total oil production of the oil well mining area driven by elastic energy also includes: According to the oil production dΔV1 driven by elastic energy in the microelement with a length of dx in the oil well mining area, a mathematical model V1 of the total oil production driven by elastic energy in the oil well mining area is established:

7. The method for predicting the recovery rate of crude oil elastic production according to claim 6, characterized in that: The mathematical model V2 for establishing the total crude oil reserves within the oil well mining area leakage range includes: The porosity at the m×n monitoring points is measured respectively to calculate the effective porosity of the oil well mining area. The irreducible water saturation at the m×n monitoring points is measured respectively, and the effective irreducible water saturation of the oil well mining area is calculated. Calculate the effective original pressure volume coefficient of crude oil at the original formation pressure in the oil well mining area 8. The method for predicting the recovery rate of crude oil elastic production according to claim 7, characterized in that: The mathematical model V2 for establishing the total crude oil reserves within the oil well mining area leakage range also includes: According to the effective porosity of the oil well mining area The effective irreducible water saturation of the oil well mining area and the effective porosity of the oil well mining area The mathematical model V2 for the total crude oil reserves within the oil well mining area is established as:

9. The method for predicting recovery rate of crude oil elastic production according to claim 8, characterized in that: The calculation of the elastic production recovery factor E of crude oil includes: The mathematical model of the crude oil elastic production recovery factor E of the total crude oil reserves V2 and the total oil production V1 driven by elastic energy in the oil well mining area is established as follows:

10. A prediction device, characterized in that: The prediction device is used to execute the crude oil elastic production recovery rate prediction method as described in any one of claims 1 to 9.

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