Shale oil reservoir different well type box production capacity evaluation method

Abstract

The invention provides a shale oil reservoir different well type box production capacity evaluation method, which comprises the following steps: determining a well type, selecting a box marking well, and obtaining the capacity of the marking well; establishing a reservoir factor mathematical relationship A according to the influence of the reservoir data set on the productivity, establishing a fluid factor mathematical relationship B according to the influence of the fluid data set on the productivity, and establishing an engineering factor mathematical relationship E according to the influence of the engineering data set on the productivity; constructing a dimensionless productivity evaluation equation according to the reservoir factor mathematical relationship A, the fluid factor mathematical relationship B and the engineering factor mathematical relationship E; and calculating the dimensionless productivity of the marker well according to the dimensionless productivity evaluation equation, and predicting the productivity of the new well in combination with design parameters, fluid parameters and engineering parameters of the new well. According to the productivity evaluation method, geology, fluid and engineering factors influencing productivity are comprehensively considered, the productivity evaluation precision of different box bodies in a target area is improved, and next-step target layer evaluation and well position deployment are supported.

Description

Technical Field

[0001] The invention belongs to the field of shale oil reservoir development and relates to a method for evaluating the production capacity of different well types of boxes in shale oil reservoirs. Background Art

[0002] my country is rich in shale oil resources. According to EIA (2015), China's technically recoverable shale oil resources are about 185 million tons, mainly distributed in the continental strata of many basins such as Junggar, Songliao, and Bohai Bay. However, the development of shale oil faces the problems of complex production variation patterns and difficulty in fitting and predicting production dynamics.

[0003] CN 112836173A discloses a method for calculating the production of shale oil horizontal wells: establishing a quantitative characterization model for the production change of shale oil horizontal wells; determining the values ​​of TO, Qomax, TM and DAV of the shale oil horizontal wells, substituting them into the quantitative characterization model for the production change, and calculating the daily oil production of the shale oil horizontal well on the tth day after the shale oil horizontal well is put into production. This patent mainly improves the method for the decline of production of single wells in horizontal wells, and does not take engineering factors into consideration. CN 115330060A discloses a method for calculating the production capacity of shale oil horizontal wells based on reservoir and engineering factor analysis, and mainly relates to the field of geological technology for oilfield development. This patent does not divide the shale oil sweet spot into boxes, and relies on the optimization of existing production wells. The factors are not taken into consideration, and there are obvious limitations in the horizontal production capacity prediction and box production capacity evaluation. Summary of the invention

[0004] In order to solve the technical problems existing in the prior art, the present invention provides a method for evaluating the production capacity of different well types in shale oil reservoirs. The production capacity evaluation method comprehensively considers the geological, fluid and engineering factors affecting the production capacity, improves the accuracy of production capacity evaluation of different boxes in the target area, and supports the next step of target layer evaluation and well site deployment.

[0005] In order to achieve the above technical effects, the present invention adopts the following technical solutions:

[0006] The present invention provides a method for evaluating the production capacity of different well types in shale oil reservoirs, the method comprising:

[0007] Determine the well type and select the box mark well to obtain the production capacity of the mark well;

[0008] According to the influence of reservoir data set on productivity, mathematical relationship A of reservoir factor is established; according to the influence of fluid data set on productivity, mathematical relationship B of fluid factor is established; according to the influence of engineering data set on productivity, mathematical relationship E of engineering factor is established;

[0009] According to the reservoir factor mathematical relationship A, the fluid factor mathematical relationship B and the engineering factor mathematical relationship E, a dimensionless production capacity evaluation equation is constructed;

[0010] The dimensionless productivity of the marker well is calculated according to the dimensionless productivity evaluation equation, and the productivity of the new well is predicted in combination with the design parameters, fluid parameters and engineering parameters of the new well.

[0011] As a preferred technical solution of the present invention, the reservoir factor mathematical relationship A is:

[0012] A=S o *C g / K

[0013] Where K is the permeability, μm 2 ; S o is the movable oil saturation, C g is a dimensionless relationship between reservoir parameters reflecting impermeability and movable oil saturation.

[0014] As a preferred technical solution of the present invention, the fluid factor mathematical relationship B is:

[0015]

[0016] Where μ is the crude oil viscosity, mPa·s; ρ is the crude oil density, kg / m 3 ;P d is the production pressure difference, MPa; C f A dimensionless relationship between fluid parameters that reflects non-viscosity, density, and production pressure differential.

[0017] As a preferred technical solution of the present invention, the mathematical relationship E of the engineering factor is:

[0018]

[0019] Where W is the amount of fracturing fluid, m 3 ; S is the amount of sand added, m 3 ; h is the transformation thickness of a vertical well or the horizontal section transformation length of a horizontal well or the inclined section transformation length of a highly deviated well, m; C e It is the dimensionless relationship between the engineering parameters reflecting the amount of non-fracturing fluid, the amount of sand added and the length of stimulation.

[0020] As a preferred technical solution of the present invention, the dimensionless capacity evaluation equation is:

[0021]

[0022] Wherein, q is the average daily production capacity of the marker well, t / d.

[0023] As a preferred technical solution of the present invention, the well type includes any one of a vertical well, a horizontal well or a highly deviated well.

[0024] As a preferred technical solution of the present invention, the selection conditions of the marker well include that the reservoir transformation process is representative and the production time is greater than half a year.

[0025] As a preferred technical solution of the present invention, the box drilling rate of the horizontal section of the marker well of the horizontal well is greater than 90%.

[0026] As a preferred technical solution of the present invention, the box drilling rate of the well deviation section of the marker well of the high-angle well is greater than 90%.

[0027] As a preferred technical solution of the present invention, the method for evaluating the production capacity of different well types in shale oil reservoirs includes:

[0028] Determine the well type, which includes any one of a vertical well, a horizontal well, or a highly deviated well; select a box marker well, the selection conditions of which include that the reservoir transformation process is representative and the production time is greater than half a year, and obtain the production capacity of the marker well;

[0029] Establish the mathematical relationship of reservoir factors based on the impact of reservoir data set on production capacity A

[0030] A=S o *C g / K

[0031] Establish the mathematical relationship of fluid factors based on the impact of fluid data set on production capacity B

[0032]

[0033] Establish the mathematical relationship of engineering factors based on the impact of engineering data sets on production capacity

[0034]

[0035] According to the reservoir factor mathematical relationship A, fluid factor mathematical relationship B and engineering factor mathematical relationship E, a dimensionless production capacity evaluation equation is constructed.

[0036]

[0037] The dimensionless productivity of the marker well is calculated according to the dimensionless productivity evaluation equation, and the productivity of the new well is predicted in combination with the design parameters, fluid parameters and engineering parameters of the new well.

[0038] Compared with the prior art, the present invention has at least the following beneficial effects:

[0039] (1) The present invention provides a method for evaluating the production capacity of different well types in a shale reservoir. The method is based on the division of shale reservoir boxes, ensuring that the multi-dimensional parameter data set of the marker well can take into account the principle of both the particularity and universality of the target layer;

[0040] (2) The present invention provides a method for evaluating the production capacity of different well types in shale oil reservoirs. The method analyzes the reservoir-production capacity mathematical relationship, fluid-production capacity mathematical relationship and engineering-production capacity mathematical relationship of the marker wells, and establishes a dimensionless production capacity calculation model with multi-factor constraints. The method can accurately evaluate the production capacity level under different boxes and different transformation parameters, and provides technical support for the effective development of shale oil.

[0041] (3) The present invention provides a method for evaluating the production capacity of different well types in shale oil reservoirs. The method can further analyze the influence of reservoirs, fluids and engineering factors of different boxes through dimensionless production capacity evaluation of different boxes, thus providing a basis for detailed analysis of shale oil wells.

[0042] (4) The present invention provides a method for evaluating the production capacity of different well types in shale oil reservoirs. The production capacity evaluation method establishes a method for predicting the production capacity of new wells in different types of wells, greatly improving the accuracy of shale oil production capacity prediction and providing a basis for the rational design of shale oil well optimization deployment and fracturing transformation plans. DETAILED DESCRIPTION

[0043] The technical solution of the present invention is further illustrated below through specific implementation methods.

[0044] A specific embodiment of the present invention provides a method for evaluating the production capacity of different well types in shale oil reservoirs, and the production capacity evaluation method includes:

[0045] Determine the well type and select the box mark well to obtain the production capacity of the mark well;

[0046] Establishing a reservoir factor mathematical relationship A based on the reservoir data set, establishing a fluid factor mathematical relationship B based on the fluid data set, and establishing an engineering factor mathematical relationship E based on the engineering data set;

[0047] According to the reservoir factor mathematical relationship A, the fluid factor mathematical relationship B and the engineering factor mathematical relationship E, a dimensionless production capacity evaluation equation is constructed;

[0048] The dimensionless productivity of the marker well is calculated according to the dimensionless productivity evaluation equation, and the productivity of the new well is predicted in combination with the design parameters, fluid parameters and engineering parameters of the new well.

[0049] In the present invention, a mathematical model is established to construct a dimensionless calculation formula for capacity evaluation by analyzing the reservoir-capacity mathematical relationship, fluid-capacity mathematical relationship and engineering-capacity mathematical relationship of existing different well types, and the capacity and geological data sets, fluid data sets and engineering data sets are dimensionless, thereby improving the capacity prediction accuracy of different well type box production.

[0050] In a specific embodiment of the present invention, the representativeness of the reservoir transformation process can be differentiated according to the characteristics of different shale oil reservoirs. It is well known in the art to determine whether the oil well reservoir transformation process is representative, and the representativeness is not specifically limited herein.

[0051] In a specific embodiment of the present invention, the reservoir data set specifically refers to the data set between reservoir parameters and production capacity, the fluid data set specifically refers to the data set between fluid parameters and production capacity, and the engineering data set specifically refers to the data set between engineering transformation parameters and production capacity.

[0052] In one embodiment of the present invention, the dimensionless relationship C g Specifically, it refers to the use of the Delphi method to compare and evaluate the impact of porosity, pore throat size, connectivity, and wettability on new wells relative to landmark wells. If it is greater than 1, it means that it has a positive effect on production capacity, and if it is less than 1, it means that it has a negative effect on production capacity.

[0053] In one embodiment of the present invention, the dimensionless relationship C f Specifically, it refers to the use of the Delphi method to compare and evaluate the impact of the gas-oil ratio and heavy hydrocarbon components on the new well relative to the marker well. If it is greater than 1, it means that it has a positive effect on the production capacity, and if it is less than 1, it means that it has a negative effect on the production capacity.

[0054] In one embodiment of the present invention, the dimensionless relationship C e Specifically, the Delphi method is used to compare and evaluate the impact of horizontal segment stress gradient, segment and cluster spacing on new wells relative to the marker wells. If it is greater than 1, it means that it has a positive effect on production capacity, and if it is less than 1, it means that it has a negative effect on production capacity.

[0055] In a specific embodiment of the present invention, the daily average production capacity q of the marker well can be further defined as the daily average of the cumulative oil production in the three months after the drainage production reaches the peak value.

[0056] In a specific embodiment of the present invention, the dimensionless capacity evaluation equation is used for calculation, and the dimensionless capacity of different boxes is evaluated by comparing the calculation results. The larger the dimensionless capacity, the better the box development effect under the current technical conditions. The mathematical relationship A of the reservoir factor, the mathematical relationship B of the fluid factor, and the mathematical relationship E of the engineering factor of different boxes are compared and analyzed to clarify the main influencing factors of the capacity difference.

[0057] To better illustrate the present invention and facilitate understanding of the technical solution of the present invention, typical but non-limiting embodiments of the present invention are as follows:

[0058] Example 1

[0059] This embodiment provides a method for evaluating the production capacity of different well types in a shale oil reservoir, and the production capacity evaluation method includes:

[0060] Determine that the well type used in the box is a vertical well;

[0061] The three boxes a, b, and c are preferably marked with wells a1, b1, and c1;

[0062] Get the production capacity of wells a1, b1, and c1 q(a1) = 28 t / d, q(b1) = 30 t / d, q(c1) = 15 t / d;

[0063] A multidimensional parameter data set related to the production capacity of boxes a, b, and c is established to determine the mathematical relationships of the reaction reservoir factors A(a), A(b), and A(c), the mathematical relationships of the reaction fluid factors B(a), B(b), and B(c), and the mathematical relationships of the reaction engineering factors E(a), E(b), and E(c). The calculation results are shown in Table 1.

[0064] Table 1

[0065] a b c A 8 6 8 B 3 3 2 E 0.03 0.02 0.02

[0066] The dimensionless production capacities of the three boxes a, b, and c are calculated as QD(a)=20.16, QD(b)=10.8, and QD(c)=4.8, and ranked and evaluated. The dimensionless production capacity of QD(a) is the largest, and box a is determined to be the optimal box for the next development and deployment.

[0067] Predict the actual production capacity of the new well a2 in box a: According to the reservoir parameters, fluid parameters and engineering design parameters near well a2, A(a2)=7, B(a2)=3, E(a2)=0.04, and the calculated QD(a)=20.16, the predicted production capacity of well a2 is calculated using the formula, and q(a2)=24t / d is obtained.

[0068] The applicant declares that the present invention illustrates the detailed structural features of the present invention through the above-mentioned embodiments, but the present invention is not limited to the above-mentioned detailed structural features, that is, it does not mean that the present invention must rely on the above-mentioned detailed structural features to be implemented. Those skilled in the art should understand that any improvement of the present invention, equivalent replacement of the components selected by the present invention, addition of auxiliary components, selection of specific methods, etc., all fall within the protection scope and disclosure scope of the present invention.

[0069] The preferred embodiments of the present invention are described in detail above. However, the present invention is not limited to the specific details in the above embodiments. Within the technical concept of the present invention, a variety of simple modifications can be made to the technical solution of the present invention, and these simple modifications all belong to the protection scope of the present invention.

[0070] It should also be noted that the various specific technical features described in the above specific embodiments can be combined in any suitable manner without contradiction. In order to avoid unnecessary repetition, the present invention will not further describe various possible combinations.

[0071] In addition, various embodiments of the present invention may be arbitrarily combined, and as long as they do not violate the concept of the present invention, they should also be regarded as the contents disclosed by the present invention.

Claims

1. A method for evaluating the production capacity of different well types in shale oil reservoirs, characterized in that: The capacity evaluation method comprises: Determine the well type and select the box mark well to obtain the production capacity of the mark well; According to the influence of reservoir data set on productivity, mathematical relationship A of reservoir factor is established; according to the influence of fluid data set on productivity, mathematical relationship B of fluid factor is established; according to the influence of engineering data set on productivity, mathematical relationship E of engineering factor is established; According to the reservoir factor mathematical relationship A, the fluid factor mathematical relationship B and the engineering factor mathematical relationship E, a dimensionless production capacity evaluation equation is constructed; The dimensionless productivity of the marker well is calculated according to the dimensionless productivity evaluation equation, and the productivity of the new well is predicted in combination with the design parameters, fluid parameters and engineering parameters of the new well.

2. The capacity evaluation method according to claim 1, characterized in that: The reservoir factor mathematical relationship A is: A=S o *C g / K Where K is the permeability, μm 2 ; S o is the movable oil saturation, C g is a dimensionless relationship between reservoir parameters reflecting impermeability and movable oil saturation.

3. The capacity evaluation method according to claim 1, characterized in that: The mathematical relationship B of the fluid factor is: Where μ is the crude oil viscosity, mPa·s; ρ is the crude oil density, kg / m 3 ;P d is the production pressure difference, MPa; C f A dimensionless relationship between fluid parameters that reflects non-viscosity, density, and production pressure differential.

4. The capacity evaluation method according to claim 1, characterized in that: The engineering factor mathematical relationship E is: Where W is the amount of fracturing fluid, m 3 ; S is the amount of sand added, m 3 ; h is the transformation thickness of a vertical well or the horizontal section transformation length of a horizontal well or the inclined section transformation length of a highly deviated well, m; C e It is the dimensionless relationship between the engineering parameters reflecting the amount of non-fracturing fluid, the amount of sand added and the length of stimulation.

5. The capacity evaluation method according to claim 4, characterized in that: The dimensionless capacity evaluation equation is: Wherein, q is the average daily production capacity of the marker well, t / d.

6. The capacity evaluation method according to claim 1, characterized in that: The well type includes any one of a vertical well, a horizontal well or a highly deviated well.

7. The capacity evaluation method according to claim 1, characterized in that: The selection criteria for the marker wells include that the reservoir transformation process is representative and the production time is greater than half a year.

8. The capacity evaluation method according to claim 6, characterized in that: The box drilling rate of the horizontal section of the marker well of the horizontal well is greater than 90%.

9. The capacity evaluation method according to claim 6, characterized in that: The box drilling rate of the well deviation section of the marker well of the high-angle well is greater than 90%.

10. The capacity evaluation method according to any one of claims 1 to 9, characterized in that: The capacity evaluation method comprises: Determine the well type, which includes any one of a vertical well, a horizontal well, or a highly deviated well; select a box marker well, the selection conditions of which include that the reservoir transformation process is representative and the production time is greater than half a year, and obtain the production capacity of the marker well; Establish the mathematical relationship of reservoir factors based on the impact of reservoir data set on production capacity A A=S o *C g / K Establish the mathematical relationship of fluid factors based on the impact of fluid data set on production capacity B Establish the mathematical relationship of engineering factors based on the impact of engineering data sets on production capacity According to the reservoir factor mathematical relationship A, fluid factor mathematical relationship B and engineering factor mathematical relationship E, a dimensionless production capacity evaluation equation is constructed. The dimensionless productivity of the marker well is calculated according to the dimensionless productivity evaluation equation, and the productivity of the new well is predicted in combination with the design parameters, fluid parameters and engineering parameters of the new well.

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