Shale oil reservoir screening technology suitable for carbon dioxide oil displacement and burying

Abstract

The invention discloses a shale oil reservoir screening technology suitable for carbon dioxide oil displacement and burying, and relates to the technical field of oil reservoir screening, the method comprises the following steps: determining the suitability degree of each to-be-screened oil reservoir based on each evaluation index of each to-be-screened oil reservoir; primary screening is conducted on all the to-be-screened oil reservoirs through the suitability degree, and the primarily-screened oil reservoirs are obtained; on the basis of the first single well yield calculation parameters of the oil reservoirs obtained after primary screening, the single well yield of the oil reservoirs obtained after primary screening in the CO2 oil displacement effective peak period is calculated; based on the second single well yield calculation parameters of the oil reservoirs obtained after primary screening, the economic limit CO2 flooding single well yield of the oil reservoirs obtained after primary screening is calculated; and determining the primarily screened oil reservoir of which the single well yield is greater than the economic limit CO2 flooding single well yield in the CO2 flooding effective peak period as a target oil reservoir. According to the method, screening of deep shale oil reservoirs suitable for CO2 flooding is achieved.

Description

Technical Field

[0001] The present application relates to the field of oil reservoir screening technology, and in particular to a shale oil reservoir screening technology suitable for carbon dioxide oil recovery and storage. Background Art

[0002] Among the oil reservoirs that have been discovered or developed in China in recent years, the proportion of deep shale oil reservoirs has gradually increased, and the oil and gas reserves are huge, which is an important position for increasing reserves and production. The reservoir properties of this type of oil and gas reservoirs are poor, water injection development is difficult, and the injection and production effect is poor. 2 Flooding can effectively maintain formation pressure and is not prone to water sensitivity. However, CO injection in deep shale reservoirs 2 The displacement effect is limited by many reservoir conditions, so in CO 2 Before flooding, candidate reservoirs need to be screened and evaluated. 2 Since the development of oil recovery, different scholars have proposed different screening technologies and evaluation methods. Taber JJ et al. proposed different reservoir and fluid parameters as screening parameters to select suitable 2 Reservoir screening for oil recovery, but the research parameters are not comprehensive enough. Many scholars have also focused on CO injection 2 The screening criteria for flooding reservoirs have been studied and many meaningful methods have been proposed, such as the fuzzy analytic hierarchy process proposed by Zheng Yunchuan et al. However, the methods are relatively simple and there are certain defects in simply using the objective weighting method to determine the index weights. In addition, the above methods generally only consider CO 2 The economic evaluation of CO2 displacement has not been paid attention to. 2 Oil recovery technology is only used in mines, and there is no comprehensive and unified screening qualitative and quantitative evaluation method, nor is there a method that can reflect the CO 2 Economic issues in flooding are not conducive to CO injection in deep shale reservoirs 2 Oil recovery development cannot be carried out for CO 2 Screening of deep shale reservoirs for flooding. Summary of the invention

[0003] The purpose of this application is to provide a shale oil reservoir screening technology suitable for carbon dioxide flooding and storage, so as to solve the problem of not being able to carry out 2 The problem of screening deep shale reservoirs for flooding.

[0004] To achieve the above objectives, this application provides the following solutions.

[0005] The present application provides a shale oil reservoir screening technology suitable for carbon dioxide flooding and storage, including: Acquire multiple evaluation indicators of multiple oil reservoirs to be screened; the evaluation indicators include: reference indicators and comparison indicators, the reference indicator is the recovery factor increase, and the comparison indicators include: formation pressure, remaining oil saturation, formation depth, permeability, porosity, formation crude oil viscosity, formation crude oil density and reservoir temperature; Determining the suitability of each oil reservoir to be screened based on each evaluation index of the evaluation index of each oil reservoir to be screened; Using the suitability, each oil reservoir to be screened is initially screened to obtain an oil reservoir after the initial screening; Obtain the first single well production calculation parameters and the second single well production calculation parameters of each initially screened oil reservoir; the first single well production calculation parameters include: CO 2 The water flooding production increase multiple and the water flooding single well production, the second single well production calculation parameters include: average single well fixed investment, fixed investment loan interest rate, project construction period, discount rate, project evaluation period, project implementation time, fixed asset residual value rate, injection and production well number ratio and crude oil commodity rate; Based on the first single well production calculation parameters of each initially screened reservoir, the CO 2 The single well production during the peak period of oil recovery; Based on the second single well production calculation parameters of each initially screened reservoir, the economic limit CO of each initially screened reservoir is calculated. 2 Production of single well; CO 2 The single well production during the peak period of oil recovery is greater than the economic limit. 2 The reservoirs after the initial screening of single well production are determined as target reservoirs.

[0006] Optionally, based on the evaluation indicators of the evaluation indicators of the oil reservoirs to be screened, determining the suitability of each oil reservoir to be screened includes: Normalizing the evaluation index of each oil reservoir to be screened respectively to obtain a plurality of normalized evaluation indexes of each oil reservoir to be screened; Based on the normalized evaluation indexes of each oil reservoir to be screened, determining the correlation coefficients corresponding to the multiple comparison indexes of each oil reservoir to be screened; the correlation coefficients are the correlation coefficients between the comparison index and the reference index and the correlation coefficients of the reference index itself; For any current comparison index, determining the correlation degree of the current comparison index based on the correlation coefficients corresponding to the current comparison indexes of all the reservoirs to be screened; Based on the correlation of all comparison indicators and the correlation of reference indicators, the correlation of each evaluation indicator is normalized to obtain the weight coefficient of each evaluation indicator; the correlation of the reference indicator is 1; The suitability of each reservoir to be screened is determined based on all normalized evaluation indicators and corresponding weight coefficients of each reservoir to be screened.

[0007] Optionally, the evaluation indexes of each oil reservoir to be screened are normalized respectively to obtain a plurality of normalized evaluation indexes of each oil reservoir to be screened, including: The recovery factor increase of each oil reservoir to be screened is normalized by using the first normalization formula to obtain the normalized recovery factor increase of each oil reservoir to be screened; the first normalization formula is: ; in, is the normalized recovery factor increase of the kth reservoir to be screened, , is the number of reservoirs to be screened; is the recovery factor increase of the kth reservoir to be screened; is the maximum value of the recovery factor increase of n reservoirs to be screened; The second normalization formula is used to normalize the formation pressure, remaining oil saturation, formation depth, permeability and porosity of each oil reservoir to be screened, respectively, to obtain the normalized formation pressure, normalized remaining oil saturation, normalized formation depth, normalized permeability and normalized porosity of each oil reservoir to be screened; the second normalization formula is: ; in, is the tth normalized comparison index of the kth reservoir to be screened, , is the number of comparison indicators; is the tth comparison index of the kth reservoir to be screened; is the maximum value of the tth comparison index of n reservoirs to be screened; The third normalization formula is used to normalize the formation crude oil viscosity and the formation crude oil density of each oil reservoir to be screened, respectively, to obtain the normalized formation crude oil viscosity and the normalized formation crude oil density of each oil reservoir to be screened; the third normalization formula is: ; The fourth normalization formula is used to normalize the reservoir temperature of each oil reservoir to be screened, and the normalized reservoir temperature of each oil reservoir to be screened is obtained; the fourth normalization formula is: ; in, for The maximum value among the absolute values ​​of the differences with the tth comparison index of the n reservoirs to be screened; is the mean value of the tth comparison index of n reservoirs to be screened.

[0008] Optionally, based on each normalized evaluation index of each oil reservoir to be screened, determining the correlation coefficient corresponding to a plurality of comparison indexes of each oil reservoir to be screened includes: The correlation coefficient calculation formula is used to calculate the correlation coefficient corresponding to the multiple comparison indicators of each oil reservoir to be screened according to the normalized evaluation indicators of each oil reservoir to be screened; the correlation coefficient calculation formula is: ; in, is the correlation coefficient corresponding to the tth comparison index of the kth reservoir to be screened; is the minimum value among the minimum comparison indexes of the n reservoirs to be screened, and the minimum comparison index is the normalized comparison index with the minimum absolute value of the difference between the normalized reference index and the kth reservoir to be screened; is the resolution coefficient; is the maximum value among the maximum comparison indexes of the n oil reservoirs to be screened, and the maximum comparison index is the normalized comparison index with the largest absolute value of the difference between the normalized reference index and the kth oil reservoir to be screened; for and The absolute value of the difference.

[0009] Optionally, for any current comparison index, the correlation degree of the current comparison index is determined based on the correlation coefficients corresponding to the current comparison indexes of all the reservoirs to be screened, including: The correlation degree calculation formula is used to calculate the correlation degree of the current comparison index according to the correlation coefficient corresponding to the current comparison index of all the reservoirs to be screened; the correlation degree calculation formula is: ; in, is the correlation degree of the tth comparison index.

[0010] Optionally, based on the correlation of all comparison indicators and the correlation of reference indicators, the correlation of each evaluation indicator is normalized to obtain a weight coefficient of each evaluation indicator, including: The fifth normalization formula is used to normalize the correlation of each evaluation indicator according to the correlation of all comparison indicators and the correlation of the reference indicator to obtain the weight coefficient of each evaluation indicator; the fifth normalization formula includes: ; ; in, is the weight coefficient of the tth comparison index; is the correlation degree of the reference indicator; is the weight coefficient of the reference indicator.

[0011] Optionally, the suitability of each oil reservoir to be screened is determined based on all normalized evaluation indicators and corresponding weight coefficients of each oil reservoir to be screened, including: The suitability calculation formula is used to calculate the suitability of each reservoir to be screened according to all normalized evaluation indicators and corresponding weight coefficients of each reservoir to be screened; the suitability calculation formula is: ; in, is the suitability of the kth reservoir to be screened.

[0012] According to the specific embodiments provided in this application, this application discloses the following technical effects: The present application discloses a shale oil reservoir screening technology suitable for carbon dioxide flooding and storage. First, multiple evaluation indicators of multiple oil reservoirs to be screened are obtained; the evaluation indicators include: reference indicators and comparison indicators, the reference indicator is the recovery factor increase, and the comparison indicators include: formation pressure, remaining oil saturation, formation burial depth, permeability, porosity, formation crude oil viscosity, formation crude oil density and reservoir temperature; based on each evaluation indicator of the evaluation indicators of each oil reservoir to be screened, the suitability of each oil reservoir to be screened is determined; secondly, using the suitability, each oil reservoir to be screened is initially screened to obtain the initially screened oil reservoir; then, the first single well production calculation parameter and the second single well production calculation parameter of each initially screened oil reservoir are obtained; thirdly, based on the first single well production calculation parameter of each initially screened oil reservoir, the CO of each initially screened oil reservoir is calculated. 2 The single well production at the peak of oil recovery is calculated based on the second single well production calculation parameters of each initially screened reservoir, and the economic limit CO of each initially screened reservoir is calculated. 2 Finally, CO 2 The single well production during the peak period of oil recovery is greater than the economic limit. 2 The reservoirs after the initial screening of the single well production are determined as target reservoirs. 2 The suitability of oil recovery enhancement is evaluated by evaluating the economic performance of reservoirs that meet the suitability standards, and finally the reservoirs suitable for CO 2 The deep shale reservoir well area suitable for CO2 flooding and storage has solved the problems of difficulty in screening shale reservoirs suitable for CO2 flooding and storage, low feasibility, and poor screening effect. 2 Provide theoretical basis for oil displacement screening. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] In order to more clearly illustrate the technical solutions in the embodiments of the present application or related technologies, the drawings required for use in the embodiments 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 work.

[0014] Figure 1 A schematic diagram of a shale oil reservoir screening technology process suitable for carbon dioxide recovery and storage provided in one embodiment of the present application. DETAILED DESCRIPTION

[0015] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only 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.

[0016] The purpose of this application is to provide a shale reservoir screening technology suitable for carbon dioxide flooding and storage, aiming to achieve 2 Screening of deep shale reservoirs for flooding.

[0017] In order to make the above-mentioned objects, features and advantages of the present application more obvious and easy to understand, the present application is further described in detail below in conjunction with the accompanying drawings and specific implementation methods.

[0018] In an exemplary embodiment, Figure 1 As shown, a shale oil reservoir screening technology suitable for carbon dioxide oil recovery and storage is provided, including the following steps.

[0019] Step 1: Obtain multiple evaluation indicators of multiple reservoirs to be screened.

[0020] Among them, the evaluation indicators include: reference indicators and comparison indicators. The reference indicator is the recovery factor increase, and the comparison indicators include: formation pressure, remaining oil saturation, formation burial depth, permeability, porosity, formation crude oil viscosity, formation crude oil density and reservoir temperature.

[0021] Step 2: Determine the suitability of each oil reservoir to be screened based on the evaluation indicators of each oil reservoir to be screened.

[0022] As an optional implementation, step 2 includes the following steps.

[0023] Step 21: Normalize the evaluation index of each oil reservoir to be screened respectively to obtain a plurality of normalized evaluation indexes of each oil reservoir to be screened.

[0024] As an optional implementation, step 21 includes the following steps.

[0025] Step 211: using the first normalization formula, normalize the recovery factor increase of each oil reservoir to be screened, and obtain the normalized recovery factor increase of each oil reservoir to be screened; the first normalization formula is: .

[0026] in, is the normalized recovery factor increase of the kth reservoir to be screened, , is the number of reservoirs to be screened; is the recovery factor increase of the kth reservoir to be screened; It is the maximum value of the recovery factor increase of n reservoirs to be screened.

[0027] Step 212: using the second normalization formula, normalizing the formation pressure, remaining oil saturation, formation depth, permeability and porosity of each oil reservoir to be screened, respectively, to obtain the normalized formation pressure, normalized remaining oil saturation, normalized formation depth, normalized permeability and normalized porosity of each oil reservoir to be screened; the second normalization formula is: .

[0028] in, is the tth normalized comparison index of the kth reservoir to be screened, , is the number of comparison indicators; is the tth comparison index of the kth reservoir to be screened; It is the maximum value of the tth comparison index among the n reservoirs to be screened.

[0029] Step 213: using the third normalization formula, normalize the formation crude oil viscosity and formation crude oil density of each oil reservoir to be screened, respectively, to obtain the normalized formation crude oil viscosity and normalized formation crude oil density of each oil reservoir to be screened; the third normalization formula is: .

[0030] Step 214: using the fourth normalization formula, normalize the reservoir temperature of each to-be-screened reservoir to obtain the normalized reservoir temperature of each to-be-screened reservoir; the fourth normalization formula is: .

[0031] in, for The maximum value among the absolute values ​​of the differences with the tth comparison index of the n reservoirs to be screened; is the mean value of the tth comparison index of n reservoirs to be screened.

[0032] Step 22: Based on the normalized evaluation indicators of each oil reservoir to be screened, determine the correlation coefficient corresponding to the multiple comparison indicators of each oil reservoir to be screened; the correlation coefficient is the correlation coefficient between the comparison indicator and the reference indicator and the correlation coefficient of the reference indicator itself.

[0033] As an optional implementation, step 22 includes: The correlation coefficient calculation formula is used to calculate the correlation coefficients corresponding to the multiple comparison indicators of each reservoir to be screened according to the normalized evaluation indicators of each reservoir to be screened. The correlation coefficient calculation formula is: .

[0034] in, is the correlation coefficient corresponding to the tth comparison index of the kth reservoir to be screened; is the minimum value among the minimum comparison indexes of the n reservoirs to be screened, and the minimum comparison index is the normalized comparison index with the minimum absolute value of the difference between the normalized reference index and the kth reservoir to be screened; is the resolution coefficient, The smaller the size, the greater the resolution. The value range of is (0, 1), and the specific value can be determined according to the situation. When the resolution is the best, usually ; is the maximum value among the maximum comparison indexes of the n oil reservoirs to be screened, and the maximum comparison index is the normalized comparison index with the largest absolute value of the difference between the normalized reference index and the kth oil reservoir to be screened; for and The absolute value of the difference.

[0035] Step 23: For any current comparison index, the correlation degree of the current comparison index is determined based on the correlation coefficients corresponding to the current comparison indexes of all the reservoirs to be screened.

[0036] As an optional implementation, step 23 includes: The correlation degree calculation formula is used to calculate the correlation degree of the current comparison index according to the correlation coefficient corresponding to the current comparison index of all the reservoirs to be screened; the correlation degree calculation formula is: .

[0037] in, is the correlation degree of the tth comparison index.

[0038] Step 24: Based on the correlation of all comparison indicators and the correlation of reference indicators, the correlation of each evaluation indicator is normalized to obtain the weight coefficient of each evaluation indicator; the correlation of the reference indicator is 1.

[0039] As an optional implementation, step 24 includes: Using the fifth normalization formula, the correlation of each evaluation indicator is normalized according to the correlation of all comparison indicators and the correlation of reference indicators to obtain the weight coefficient of each evaluation indicator; the fifth normalization formula includes: .

[0040] .

[0041] in, is the weight coefficient of the tth comparison index; is the correlation degree of the reference indicator; is the weight coefficient of the reference indicator.

[0042] Specifically, the larger the weight coefficient of the evaluation index is, the more important the evaluation index is for CO 2 The greater the impact of oil displacement on enhanced oil recovery.

[0043] Step 25: Determine the suitability of each oil reservoir to be screened based on all normalized evaluation indicators and corresponding weight coefficients of each oil reservoir to be screened.

[0044] As an optional implementation, step 25 includes: The suitability calculation formula is used to calculate the suitability of each reservoir to be screened according to all normalized evaluation indicators and corresponding weight coefficients of each reservoir to be screened; the suitability calculation formula is: .

[0045] in, is the suitability of the kth reservoir to be screened.

[0046] Step 3: Use suitability to conduct a preliminary screening of each reservoir to be screened, and obtain the reservoirs after the preliminary screening.

[0047] Specifically, the reservoirs to be screened with a suitability greater than 0.6 are determined as the reservoirs after the initial screening. 2 The better the oil recovery effect, the better the oil recovery effect. The suitability is divided into four intervals, and the initial screening of reservoirs is carried out according to these intervals. The reservoirs to be screened with a suitability greater than 0.6 are Class I reservoirs, and CO 2 The suitability for oil recovery is high, CO 2The oil displacement effect is the best; the reservoirs to be screened with a suitability in the range of 0.5 to 0.6 are Class II reservoirs, and CO 2 The oil displacement effect is good, and its oil displacement effect varies little with reservoir conditions; the reservoirs to be screened with a suitability in the range of 0.4 to 0.5 are Class III reservoirs, and CO 2 The oil recovery effect varies greatly with reservoir conditions; the reservoirs to be screened with a suitability of less than 0.4 are Class IV reservoirs, and CO 2 The oil displacement effect is relatively poor.

[0048] Step 4: Obtain the first single well production calculation parameters and the second single well production calculation parameters of each initially screened oil reservoir.

[0049] Among them, the first single well production calculation parameters include: CO 2 The water drive production increase multiple and water drive single well production, the second single well production calculation parameters include: average single well fixed investment, fixed investment loan interest rate, project construction period, discount rate, project evaluation period, project implementation time, fixed asset residual value rate, injection and production wells ratio and crude oil commodity rate.

[0050] Step 5: Calculate the CO of each initially screened reservoir based on the first single well production calculation parameters of each initially screened reservoir. 2 The single well production during the peak period of oil recovery.

[0051] Specifically, the first production calculation formula is used to calculate the CO of each initially screened reservoir according to the first single well production calculation parameters of each initially screened reservoir. 2 The single well production during the peak period of oil recovery is calculated using the first production calculation formula: .

[0052] in, CO 2 The single well production during the peak period of oil recovery; CO 2 The flooding increase factor is CO 2 The ratio of the single well production during the peak period of oil recovery to the single well production during the peak period of water recovery; It is the single well production during the peak period of water flooding.

[0053] Step 6: Calculate the economic limit CO of each initially screened reservoir based on the second single well production calculation parameters of each initially screened reservoir. 2 Flooding single well production.

[0054] Specifically, the economic limit CO of each initially screened reservoir is calculated using the second production calculation formula according to the second single well production calculation parameters of each initially screened reservoir. 2The second production calculation formula for driving single well production is: .

[0055] in, is the economic limit of the reservoir CO 2 Production of single well; is the average fixed investment per well; To fix the investment loan interest rate; During the project construction period; It is the difference between the project implementation time and the project construction period; The time for project implementation; is the discount rate; is the residual value rate of fixed assets; This is the project evaluation period; is the crude oil commodity rate; is the well pattern coefficient; is the ratio of injection wells to production wells.

[0056] Step 7: CO 2 The single well production during the peak period of oil recovery is greater than the economic limit. 2 The reservoirs after the initial screening of single well production are determined as target reservoirs.

[0057] Specifically, when When the target reservoir is suitable for CO 2 Drive, can generate economic benefits.

[0058] Furthermore, several typical deep shale oil reservoirs were selected as examples, and with reference to the evaluation standards of various countries and the collection and statistics of actual data, the factors that ultimately affected the reservoir were determined to be formation pressure, remaining oil saturation, formation crude oil viscosity, surface crude oil density, formation burial depth, permeability, porosity, reservoir temperature and recovery factor increase. The recovery factor increase was selected as the reference indicator, and the remaining evaluation indicators were used as comparison indicators, as shown in Table 1.

[0059] .

[0060] Each evaluation index is normalized, and the normalized evaluation index is shown in Table 2.

[0061] .

[0062] The correlation coefficients between each evaluation index and the recovery factor increase were calculated using the normalized evaluation indexes, as shown in Table 3.

[0063] .

[0064] The correlation degree and weight coefficient are calculated through the correlation coefficient, as shown in Table 4.

[0065] .

[0066] Finally, the suitability of the selected oil fields was calculated: Oil field 1 was 0.611648; Oil field 2 was 0.644877; Oil field 3 was 0.388285; Oil field 4 was 0.659166; and Oil field 5 was 0.499739.

[0067] According to the reservoir suitability classification, oil fields 1, 2, and 4 are Class I reservoirs. 2 The suitability for oil recovery is high, CO 2 The oil displacement effect is the best; 5 oil fields are Class III reservoirs, with a suitability of 0.4-0.5, CO 2 The oil recovery effect varies greatly with reservoir conditions; Oilfield 3 is a Class IV reservoir with a suitability of <0.4. 2 The oil displacement effect is relatively poor. The economic evaluation of the above-screened Class I reservoirs was carried out, and the secondary screening of the reservoirs was carried out. The screening results are given in Table 5.

[0068] .

[0069] After two rounds of screening, oil fields 1 and 4 were finally selected as suitable for CO 2 The oil fields that are driven by hydraulic flotation can not only meet the requirements of improving the recovery rate, but also achieve certain economic benefits.

[0070] The technical features of the above embodiments may be combined arbitrarily. To make the description concise, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0071] This article uses specific examples to illustrate the principles and implementation methods of this application. The description of the above embodiments is only used to help understand the method and core ideas of this application. At the same time, for those skilled in the art, according to the ideas of this application, there will be changes in the specific implementation methods and application scope. In summary, the content of this specification should not be understood as limiting this application.

Claims

1. A shale oil reservoir screening technology suitable for carbon dioxide flooding and storage, characterized in that: The shale oil reservoir screening technology suitable for carbon dioxide flooding and storage includes: Acquire multiple evaluation indicators of multiple oil reservoirs to be screened; the evaluation indicators include: reference indicators and comparison indicators, the reference indicator is the recovery factor increase, and the comparison indicators include: formation pressure, remaining oil saturation, formation depth, permeability, porosity, formation crude oil viscosity, formation crude oil density and reservoir temperature; Determining the suitability of each oil reservoir to be screened based on each evaluation index of the evaluation index of each oil reservoir to be screened; Using the suitability, each oil reservoir to be screened is initially screened to obtain an oil reservoir after the initial screening; Obtaining the first single well production calculation parameters and the second single well production calculation parameters of each initially screened oil reservoir; the first single well production calculation parameters include: CO2 drive production increase multiple and water drive single well production, and the second single well production calculation parameters include: average single well fixed investment, fixed investment loan interest rate, project construction period, discount rate, project evaluation period, project implementation time, fixed asset residual value rate, injection-production well number ratio and crude oil commodity rate; Based on the first single well production calculation parameters of each initially screened oil reservoir, the single well production of each initially screened oil reservoir at the peak period of CO2 flooding effectiveness is calculated; The economic limit CO2 flooding single well production of each initially screened oil reservoir is calculated based on the second single well production calculation parameters of each initially screened oil reservoir; The oil reservoirs after the initial screening whose single well production during the peak period of CO2 flooding effectiveness is greater than the economic limit CO2 flooding single well production are determined as target oil reservoirs.

2. The shale oil reservoir screening technology suitable for carbon dioxide flooding and storage according to claim 1 is characterized in that: Based on the evaluation indicators of each reservoir to be screened, the suitability of each reservoir to be screened is determined, including: Normalizing the evaluation index of each oil reservoir to be screened respectively to obtain a plurality of normalized evaluation indexes of each oil reservoir to be screened; Based on the normalized evaluation indexes of each oil reservoir to be screened, determining the correlation coefficients corresponding to the multiple comparison indexes of each oil reservoir to be screened; the correlation coefficients are the correlation coefficients between the comparison index and the reference index and the correlation coefficients of the reference index itself; For any current comparison index, determining the correlation degree of the current comparison index based on the correlation coefficients corresponding to the current comparison indexes of all the reservoirs to be screened; Based on the correlation of all comparison indicators and the correlation of reference indicators, the correlation of each evaluation indicator is normalized to obtain the weight coefficient of each evaluation indicator; the correlation of the reference indicator is 1; The suitability of each reservoir to be screened is determined based on all normalized evaluation indicators and corresponding weight coefficients of each reservoir to be screened.

3. The shale oil reservoir screening technology suitable for carbon dioxide flooding and storage according to claim 2 is characterized in that: The evaluation indexes of each oil reservoir to be screened are normalized respectively to obtain multiple normalized evaluation indexes of each oil reservoir to be screened, including: The recovery factor increase of each oil reservoir to be screened is normalized by using the first normalization formula to obtain the normalized recovery factor increase of each oil reservoir to be screened; the first normalization formula is: ； in, is the normalized recovery factor increase of the kth reservoir to be screened, , is the number of reservoirs to be screened; is the recovery factor increase of the kth reservoir to be screened; is the maximum value of the recovery factor increase of n reservoirs to be screened; The second normalization formula is used to normalize the formation pressure, remaining oil saturation, formation depth, permeability and porosity of each oil reservoir to be screened, respectively, to obtain the normalized formation pressure, normalized remaining oil saturation, normalized formation depth, normalized permeability and normalized porosity of each oil reservoir to be screened; the second normalization formula is: ； in, is the tth normalized comparison index of the kth reservoir to be screened, , is the number of comparison indicators; is the tth comparison index of the kth reservoir to be screened; is the maximum value of the tth comparison index of n reservoirs to be screened; The third normalization formula is used to normalize the formation crude oil viscosity and the formation crude oil density of each oil reservoir to be screened, respectively, to obtain the normalized formation crude oil viscosity and the normalized formation crude oil density of each oil reservoir to be screened; the third normalization formula is: ； The fourth normalization formula is used to normalize the reservoir temperature of each oil reservoir to be screened, and the normalized reservoir temperature of each oil reservoir to be screened is obtained; the fourth normalization formula is: ； in, for The maximum value among the absolute values ​​of the differences with the tth comparison index of the n reservoirs to be screened; is the mean value of the tth comparison index of n reservoirs to be screened.

4. The shale oil reservoir screening technology suitable for carbon dioxide flooding and storage according to claim 3 is characterized in that: Based on the normalized evaluation indexes of each oil reservoir to be screened, the correlation coefficients corresponding to the multiple comparison indexes of each oil reservoir to be screened are determined, including: The correlation coefficient calculation formula is used to calculate the correlation coefficient corresponding to the multiple comparison indicators of each oil reservoir to be screened according to the normalized evaluation indicators of each oil reservoir to be screened; the correlation coefficient calculation formula is: ； in, is the correlation coefficient corresponding to the tth comparison index of the kth reservoir to be screened; is the minimum value among the minimum comparison indexes of the n reservoirs to be screened, and the minimum comparison index is the normalized comparison index with the minimum absolute value of the difference between the normalized reference index and the kth reservoir to be screened; is the resolution coefficient; is the maximum value among the maximum comparison indexes of the n oil reservoirs to be screened, and the maximum comparison index is the normalized comparison index with the largest absolute value of the difference between the normalized reference index and the kth oil reservoir to be screened; for and The absolute value of the difference.

5. The shale oil reservoir screening technology suitable for carbon dioxide flooding and storage according to claim 4 is characterized in that: For any current comparison index, the correlation degree of the current comparison index is determined based on the correlation coefficients corresponding to the current comparison indexes of all the reservoirs to be screened, including: The correlation degree calculation formula is used to calculate the correlation degree of the current comparison index according to the correlation coefficient corresponding to the current comparison index of all the reservoirs to be screened; the correlation degree calculation formula is: ； in, is the correlation degree of the tth comparison index.

6. The shale oil reservoir screening technology suitable for carbon dioxide flooding and storage according to claim 5 is characterized in that: Based on the correlation of all comparison indicators and the correlation of reference indicators, the correlation of each evaluation indicator is normalized to obtain the weight coefficient of each evaluation indicator, including: The fifth normalization formula is used to normalize the correlation of each evaluation indicator according to the correlation of all comparison indicators and the correlation of the reference indicator to obtain the weight coefficient of each evaluation indicator; the fifth normalization formula includes: ； ； in, is the weight coefficient of the tth comparison index; is the correlation degree of the reference indicator; is the weight coefficient of the reference indicator.

7. The shale oil reservoir screening technology suitable for carbon dioxide flooding and storage according to claim 6 is characterized in that: Based on all normalized evaluation indicators and corresponding weight coefficients of each reservoir to be screened, the suitability of each reservoir to be screened is determined, including: The suitability calculation formula is used to calculate the suitability of each reservoir to be screened according to all normalized evaluation indicators and corresponding weight coefficients of each reservoir to be screened; the suitability calculation formula is: ； in, is the suitability of the kth reservoir to be screened.

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