Method and device for determining gas injection amount of single well for displacing top attic oil

Abstract

The embodiment of the invention provides a method and device for determining the gas injection amount of a single well for displacing top attic oil. The method for determining the gas injection amount of the single well for displacing the top attic oil comprises the steps that an established reservoir simplified model is utilized, and the rock volume of a target gas injection well above the depth of an oil-gas interface is obtained; an average porosity calculation formula is used for obtaining the average porosity of rocks, above the oil-gas interface, of the target gas injection well; obtaining the gas saturation of a gas cap area of the target gas injection well above the oil-gas interface by using a gas saturation calculation formula; utilizing the deviation factor chart to obtain an expansion coefficient of the crude oil in the target gas injection well under the current oil reservoir formation pressure and the current oil reservoir temperature; and according to the rock volume, the average porosity of the rock, the gas saturation of the gas cap area and the expansion coefficient, the upper limit value of the gas injection amount of the target gas injection well is obtained through calculation.

Description

Technical Field

[0001] The present application relates to the technical field of oil and gas field development, and in particular to a method and device for determining the gas injection volume of a single well for displacing top attic oil. Background Art

[0002] The development of buried hill reservoirs mainly relies on natural bottom water drive and artificial bottom water drive. The remaining oil in the fracture system of buried hill reservoirs is mostly in the form of loft oil and inter-conical zone in the high part of the buried hill. Conventional water drive measures are difficult to mobilize such remaining oil. Figure 2 As shown, by injecting gas into the buried hill, the gas will gather at the top due to gravity differentiation and drive the attic oil downward to be produced by the oil well.

[0003] In the reservoir engineering plan, the design of the single-well gas injection volume to displace the top loft oil is one of the important parameters. How to reasonably determine the single-well gas injection volume so that the enriched oil column formed by gas injection can affect the production section of the oil well is the key to achieving better oil production results. In related technologies, reservoir engineers design the single-well gas injection volume based on manual experience, which lacks theoretical basis and pertinence and has low accuracy. When the designed gas injection volume is too small, the enriched oil column formed is thin and cannot affect the oil production well; when the gas injection volume is too large, the secondary gas cap formed is larger, causing gas flooding of the oil production well.

[0004] Therefore, how to accurately and conveniently determine the single-well gas injection volume to displace the top attic oil is a technical problem that needs to be solved urgently. Summary of the invention

[0005] The embodiments of the present application provide a method and device for determining the single-well gas injection volume for displacing top attic oil, which are used to accurately and conveniently determine the single-well gas injection volume for displacing top attic oil.

[0006] One of the embodiments of the present application provides a method for determining the gas injection volume of a single well for displacing top attic oil, the method comprising: using an established simplified reservoir model to obtain the rock volume of a target gas injection well above the oil-gas interface depth; using an average porosity calculation formula to obtain the average porosity of the rock of the target gas injection well above the oil-gas interface; using a gas saturation calculation formula to obtain the gas saturation of the gas cap zone of the target gas injection well above the oil-gas interface; using a deviation factor map to obtain the expansion coefficient of the crude oil in the target gas injection well at the current reservoir formation pressure and the current reservoir temperature; and calculating the upper limit of the gas injection volume of the target gas injection well based on the rock volume, the average porosity of the rock, the gas saturation of the gas cap zone, and the expansion coefficient.

[0007] In some embodiments, the simplified reservoir model is a conical solid geometric model; the method of using the established simplified reservoir model to obtain the rock volume of the target gas injection well above the oil-gas interface depth includes: dividing the simplified reservoir model from top to bottom into a plurality of differential units in sequence; wherein the first differential unit is a conical structure, and the remaining differential units are frustum structures; for the plurality of differential units, the rock volume V of the target gas injection well above the oil-gas interface depth is calculated using the following formula:

[0008]

[0009] Among them, s1 is the bottom area of ​​the first differential unit; h is the elevation value; s i is the bottom area of ​​the ith differential unit.

[0010] In some embodiments, the average porosity is calculated as follows:

[0011]

[0012] in, is the average porosity of the rock; N is the attic oil reserves to be displaced; B O is the volume coefficient; V1 is the rock volume above the original oil-water interface of the target gas injection well; S O is the oil saturation; ρ is the crude oil density.

[0013] In some embodiments, the gas saturation calculation formula is as follows:

[0014] S g =(1-S wi -s or )×100%

[0015] Among them, S g is the gas saturation of the gas cap zone; S wi is the bound water saturation; S or is the residual oil saturation.

[0016] In some embodiments, the use of the deviation factor map to obtain the expansion coefficient of the crude oil in the target gas injection well at the current reservoir formation pressure and the current reservoir temperature includes: using the deviation factor map to obtain the deviation factor corresponding to the current reservoir formation pressure and the current reservoir temperature; using the deviation factor, the current reservoir formation pressure and the current reservoir temperature of the target gas injection well, to obtain the expansion coefficient through the following calculation formula:

[0017] Among them, E g is the expansion coefficient; Z is the deviation factor; T is the current reservoir temperature; and P is the current reservoir formation pressure.

[0018] In some embodiments, the upper limit of the gas injection volume of the target gas injection well is calculated according to the following formula:

[0019]

[0020] Wherein, G is the upper limit of the gas injection volume of the target gas injection well; V is the rock volume above the oil-gas interface depth, m 3 ; is the average porosity; S g is the gas saturation of the gas cap zone; E g is the expansion coefficient.

[0021] One of the embodiments of the present application provides a device for determining the gas injection volume of a single well for displacing top attic oil, the device comprising: a first acquisition module, used to obtain the rock volume of a target gas injection well above the oil-gas interface depth by using an established simplified reservoir model; a second acquisition module, used to obtain the average porosity of the rock of the target gas injection well above the oil-gas interface by using an average porosity calculation formula; a third acquisition module, used to obtain the gas saturation of the gas cap zone of the target gas injection well above the oil-gas interface by using a gas saturation calculation formula; a fourth acquisition module, used to obtain the expansion coefficient of the crude oil in the target gas injection well at the current reservoir formation pressure and the current reservoir temperature by using a deviation factor map; and a fifth acquisition module, used to calculate the upper limit of the gas injection volume of the target gas injection well based on the rock volume, the average porosity of the rock, the gas saturation of the gas cap zone and the expansion coefficient.

[0022] An embodiment of the present application provides an electronic device, which includes a memory and a processor. The memory stores a computer program, and the processor executes the method described above when running the program.

[0023] An embodiment of the present application provides a storage medium for storing a computer-readable program. When the computer-readable program is executed, the method described above is executed.

[0024] The above technical solution provided by the embodiment of the present application has at least the following advantages compared with the prior art:

[0025] In the embodiment provided in the present application, the established simplified reservoir model is used to obtain the rock volume of the target gas injection well above the oil-gas interface depth; the average porosity calculation formula is used to obtain the average porosity of the rock of the target gas injection well above the oil-gas interface; the gas saturation calculation formula is used to obtain the gas saturation of the gas cap zone of the target gas injection well above the oil-gas interface; the deviation factor chart is used to obtain the expansion coefficient of the crude oil in the target gas injection well at the current reservoir formation pressure and the current reservoir temperature; according to the rock volume, the average porosity of the rock, the gas saturation of the gas cap zone and the expansion coefficient, the upper limit of the gas injection amount of the target gas injection well is calculated. Thus, the single-well gas injection amount for displacing the top attic oil can be accurately and conveniently determined. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] The present application will be further described in the form of exemplary embodiments, which will be described in detail by way of the accompanying drawings. These embodiments are not restrictive, and in these embodiments, the same number represents the same structure, wherein:

[0027] Figure 1 is an exemplary flow chart of a method for determining the amount of gas injection for displacing top attic oil in a single well according to some embodiments of the present application;

[0028] Figure 2 is an exemplary schematic diagram of gas injection gravity displacement of attic oil according to some embodiments of the present application;

[0029] Figure 3 is an exemplary schematic diagram of a simplified reservoir model according to some embodiments of the present application;

[0030] Figure 4A is an exemplary schematic diagram of a buried hill stratum section according to some embodiments of the present application;

[0031] Figure 4B is an exemplary schematic diagram of another buried hill stratum section according to some embodiments of the present application;

[0032] Figure 5 is an exemplary schematic diagram of a generalized compression factor chart drawn by Watson and Smith according to some embodiments of the present application;

[0033] Fig. 6A is an exemplary schematic diagram of a well location map of the top surface structure of the Ordovician system of the H buried hill according to some embodiments of the present application;

[0034] Figure 6B is an exemplary schematic diagram of another H buried hill Ordovician top surface structure well map according to some embodiments of the present application;

[0035] Fig. 7Ais an exemplary schematic diagram of a production curve of the Z3X well according to some embodiments of the present application;

[0036] Figure 7B is an exemplary schematic diagram of another Z3X well production curve according to some embodiments of the present application;

[0037] Figure 8 is an exemplary schematic diagram of a device for determining the gas injection amount of a single well for displacing top attic oil according to some embodiments of the present application;

[0038] Fig. 9 It is a schematic diagram of an exemplary structure of an electronic device according to some embodiments of the present application. DETAILED DESCRIPTION

[0039] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following is a brief introduction to the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some examples or embodiments of the present application. For ordinary technicians in this field, the present application can also be applied to other similar scenarios based on these drawings without creative work. Unless it is obvious from the language environment or otherwise explained, the same reference numerals in the figures represent the same structure or operation.

[0040] It should be understood that the "system", "device", "unit" and / or "module" used herein are a method for distinguishing different components, elements, parts, portions or assemblies at different levels. However, if other words can achieve the same purpose, the words can be replaced by other expressions.

[0041] As shown in this application and claims, unless the context clearly indicates an exception, the words "a", "an", "an" and / or "the" do not refer to the singular and may also include the plural. Generally speaking, the terms "comprises" and "includes" only indicate the inclusion of the steps and elements that have been clearly identified, and these steps and elements do not constitute an exclusive list. The method or device may also include other steps or elements.

[0042] Flowcharts are used in the present application to illustrate the operations performed by the system according to the embodiments of the present application. It should be understood that the preceding or following operations are not necessarily performed accurately in order. On the contrary, the various steps may be processed in reverse order or simultaneously. At the same time, other operations may also be added to these processes, or one or more operations may be removed from these processes.

[0043] For ease of understanding, the technical solution of the present application is introduced below in conjunction with the accompanying drawings and embodiments.

[0044] Figure 1FIG. 1 is an exemplary flow chart of a method for determining the amount of gas injected into a single well to displace top attic oil according to some embodiments of the present application. Figure 1 As shown, the method for determining the single well gas injection volume for displacing top attic oil includes the following steps:

[0045] Step S110, using the established simplified reservoir model, obtain the rock volume of the target gas injection well above the oil-gas interface depth.

[0046] The simplified reservoir model is a three-dimensional geometric model obtained by simplifying the reservoir of the target gas injection well above the oil-gas interface depth.

[0047] In some embodiments, Figure 4A and Figure 4B The reservoir above the oil-gas interface depth (which can be obtained using the basic dynamic and static data of the reservoir collected in advance) of the target gas injection well shown is simplified as follows Figure 3 The solid geometric model of the cone shown.

[0048] In the specific implementation process, the differential idea can be used to divide the simplified reservoir model from top to bottom into multiple differential units in sequence; wherein the first differential unit is a cone structure, and the remaining differential units are frustum structures, and the bottom area of ​​each differential unit is the same as the top area of ​​the next differential unit.

[0049] For the multiple differential units obtained by division, the rock volume V of the target gas injection well above the oil-gas interface depth is calculated using the following formula:

[0050]

[0051] Among them, s1 is the bottom area of ​​the first differential unit, in meters; h is the elevation value, in meters, which can be obtained using the basic dynamic and static data of the reservoir collected in advance; s i is the bottom area of ​​the ith differential unit, in square meters.

[0052] Step S120, using the average porosity calculation formula to obtain the average porosity of the rock above the oil-gas interface of the target gas injection well.

[0053] In the related art, core measured data is used to evaluate the porosity of the reservoir, but core sampling cannot reflect the overall condition of the reservoir porosity. Therefore, this application uses the average porosity of the reservoir for calculation. The average porosity calculation formula is as follows:

[0054]

[0055] in, is the average porosity of the rock, expressed as a percentage; B Ois the volume coefficient; S O is the oil saturation, expressed as a percentage; ρ is the crude oil density, expressed in grams per cubic meter. The volume coefficient, oil saturation and crude oil density can all be obtained from the basic dynamic and static data of the reservoir collected in advance.

[0056] N is the attic oil reserves to be displaced, which can be calculated using the following formula:

[0057]

[0058] Where N is the attic oil reserves to be displaced, in ×10 4 t; A is the oil-bearing area, unit is km 2 ; h is the oil column height, in m; is the effective porosity, expressed as a percentage; S o is the oil saturation, expressed as a percentage; ρ is the crude oil density, in g / cm 3 ; B o is the volume coefficient. The oil-bearing area, oil column height, effective porosity, oil saturation and crude oil density can all be obtained through the basic dynamic and static data of the reservoir collected in advance.

[0059] Wherein, V1 is the rock volume of the target gas injection well above the original oil-water interface (as shown in FIG. 4 , which can be obtained through the basic dynamic and static data of the reservoir collected in advance), which can be calculated using the method shown in step S110 .

[0060] Step S130, using a gas saturation calculation formula, obtain the gas saturation of the gas cap zone above the oil-gas interface of the target gas injection well.

[0061] In some embodiments, the gas saturation calculation formula is as follows:

[0062] S g =(1-S wi -S or )×100% (4)

[0063] Among them, S g is the gas saturation of the gas cap zone, expressed as a percentage; S or is the residual oil saturation, expressed as a percentage, which can be obtained through the basic dynamic and static data of the reservoir collected in advance; S wi is the bound water saturation, which can be calculated by the average gas-to-oil efficiency and residual oil saturation S of the buried-hill reservoir. or Calculated.

[0064] In the specific implementation process, the average gas-to-oil efficiency of the buried hill reservoir can be determined based on the dual-medium buried hill reservoir gas-to-oil experiment, on-site nitrogen injection numerical simulation inversion and other methods. The calculation formula is as follows:

[0065]

[0066] Among them, E D is the average gas-to-oil efficiency of buried-hill reservoirs, expressed as a percentage; S oi is the initial oil saturation, expressed as a percentage; S or is the residual oil saturation, expressed as a percentage.

[0067] The average gas-to-oil efficiency E of the buried-hill reservoir is calculated using formula (5): D Afterwards, according to E D and the original oil saturation S oi , the bound water saturation S is calculated using the following formula wi .

[0068]

[0069] Step S140, using the deviation factor map, obtain the expansion coefficient of the crude oil in the target gas injection well at the current reservoir formation pressure and the current reservoir temperature.

[0070] In the specific implementation process, the deviation factor plate can be used to obtain the deviation factor corresponding to the current reservoir formation pressure and the current reservoir temperature; the deviation factor, the current reservoir formation pressure and the current reservoir temperature of the target gas injection well are used to obtain the expansion coefficient at the current reservoir formation pressure and the current reservoir temperature through the following calculation formula:

[0071]

[0072] Among them, E g is the expansion coefficient; Z is the deviation factor; T is the current reservoir temperature, in Kelvin; P is the current reservoir formation pressure, in MPa.

[0073] As an example only, according to the current reservoir formation pressure and the current reservoir temperature, Figure 5 The comparative pressure Pr and comparative temperature Tr are obtained from the deviation factor chart shown, and then the deviation factor Z corresponding to Pr and Tr is read from the deviation factor chart; then the expansion coefficient at the current reservoir formation pressure and the current reservoir temperature is calculated using formula (7).

[0074] Step S150, calculating an upper limit value of the gas injection amount of the target gas injection well according to the rock volume, the average porosity of the rock, the gas saturation of the gas cap zone, and the expansion coefficient.

[0075] In the specific implementation process, the upper limit of the gas injection volume of the target gas injection well can be calculated according to the following formula:

[0076]

[0077] Wherein, G is the upper limit of the gas injection volume of the target gas injection well; V is the rock volume above the oil-gas interface depth, m 3 ; is the average porosity; S g is the gas saturation of the gas cap zone; E g is the expansion coefficient.

[0078] For medium-to-high permeability massive bottom water reservoirs or buried hill reservoirs with developed vertical fractures, the entire reservoir has good vertical and horizontal connectivity. Therefore, in the embodiments provided in this application, the basic idea of ​​the volumetric method is adopted to calculate the upper limit of the gas injection volume of the target gas injection well based on the rock volume above the oil-gas interface depth, the average porosity of the rock above the oil-gas interface, the gas saturation of the gas cap area above the oil-gas interface, and the expansion coefficient of the crude oil in the target gas injection well at the current reservoir formation pressure and the current reservoir temperature. In this way, the single-well gas injection volume for displacing the top attic oil can be accurately and conveniently determined, providing a theoretical basis for the design of a single-well gas injection scheme, avoiding the cost waste and unsatisfactory oil increase effect caused by excessive or insufficient gas injection volume.

[0079] The beneficial effects of the technical solution provided by this application are explained below through specific examples.

[0080] The original oil saturation of H buried hill is 80%, the reservoir temperature is 110℃, and the reservoir formation pressure is 31.6MPa. Fig. 6A and Figure 6B As shown in the figure, Well Z3X is located at the structural high point of the H buried hill. It is estimated that there is 20 m of unused loft oil above it. According to the loft oil range of -3100 m, the area of ​​the oil-gas interface is 113610 m 2 , the rock volume above the oil-gas interface depth is calculated using formula (1) to be 75.74×10 4 m 3 , the attic oil reserves to be displaced are calculated to be 2.49×10 4 t, combined with the rock volume above the oil-gas interface depth, using formula (2), the average porosity is calculated to be 6%. Combined with the deviation factor chart, using formula (7), the expansion coefficient under the current reservoir formation pressure and current reservoir temperature is calculated to be 232. Finally, using formula (8), the upper limit of the gas injection volume of Well Z3X is calculated to be 548×10 4 m 3 Some of the values ​​involved in the above calculation process are shown in the following table (Table 1):

[0081]

[0082] Table 1

[0083] like Fig. 7A and Figure 7B As shown, after implementing the method provided in this application, the Z3X well carried out three rounds of nitrogen throughput from 2020 to 2023, with a cumulative gas injection of 5.5 million cubic meters and a cumulative increase of 9,962 tons of oil, with significant oil increase effect.

[0084] Figure 8 It is an exemplary schematic diagram of a device for determining the gas injection amount of a single well for displacing top attic oil according to some embodiments of the present application.

[0085] like Figure 8 As shown, the device for determining the single-well gas injection volume for displacing top attic oil includes: a first acquisition module 810 , a second acquisition module 820 , a third acquisition module 830 , a fourth acquisition module 840 , and a fifth acquisition module 850 .

[0086] The first acquisition module 810 is used to obtain the rock volume of the target gas injection well above the oil-gas interface depth by using the established simplified reservoir model.

[0087] The second acquisition module 820 is used to obtain the average porosity of the rock above the oil-gas interface of the target gas injection well by using the average porosity calculation formula.

[0088] The third acquisition module 830 is used to obtain the gas saturation of the gas cap zone above the oil-gas interface of the target gas injection well by using a gas saturation calculation formula.

[0089] The fourth acquisition module 840 is used to obtain the expansion coefficient of the crude oil in the target gas injection well under the current reservoir formation pressure and the current reservoir temperature by using the deviation factor map.

[0090] The fifth acquisition module 850 is used to calculate the upper limit of the gas injection amount of the target gas injection well according to the rock volume, the average porosity of the rock, the gas saturation of the gas cap zone and the expansion coefficient.

[0091] In some embodiments, the simplified reservoir model is a conical solid geometric model; the method of using the established simplified reservoir model to obtain the rock volume of the target gas injection well above the oil-gas interface depth includes: dividing the simplified reservoir model from top to bottom into a plurality of differential units in sequence; wherein the first differential unit is a conical structure, and the remaining differential units are frustum structures; for the plurality of differential units, the rock volume V of the target gas injection well above the oil-gas interface depth is calculated using the following formula:

[0092]

[0093] Among them, s1 is the bottom area of ​​the first differential unit; h is the elevation value; s i is the bottom area of ​​the ith differential unit.

[0094] In some embodiments, the average porosity is calculated as follows:

[0095]

[0096] in, is the average porosity of the rock; N is the attic oil reserves to be displaced; B O is the volume coefficient; V1 is the rock volume above the original oil-water interface of the target gas injection well; S O is the oil saturation; ρ is the crude oil density.

[0097] In some embodiments, the gas saturation calculation formula is as follows:

[0098] S g =(1-S wi -S or )×100%

[0099] Among them, S g is the gas saturation of the gas cap zone; S wi is the bound water saturation; S or is the residual oil saturation.

[0100] In some embodiments, the use of the deviation factor map to obtain the expansion coefficient of the crude oil in the target gas injection well at the current reservoir formation pressure and the current reservoir temperature includes: using the deviation factor map to obtain the deviation factor corresponding to the current reservoir formation pressure and the current reservoir temperature; using the deviation factor, the current reservoir formation pressure and the current reservoir temperature of the target gas injection well, to obtain the expansion coefficient through the following calculation formula:

[0101] Among them, E g is the expansion coefficient; Z is the deviation factor; T is the current reservoir temperature; and P is the current reservoir formation pressure.

[0102] In some embodiments, the upper limit of the gas injection volume of the target gas injection well is calculated according to the following formula:

[0103]

[0104] Wherein, G is the upper limit of the gas injection volume of the target gas injection well; V is the rock volume above the oil-gas interface depth, m 3 ; is the average porosity; S g is the gas saturation of the gas cap zone; E g is the expansion coefficient.

[0105] In the above-mentioned embodiment of the device for determining the single-well gas injection volume for displacing top attic oil, the specific processing of each module and the technical effects brought about by it can be referred to the relevant descriptions in the corresponding method embodiment, which will not be repeated here.

[0106] Fig. 9 It is a schematic diagram of an exemplary structure of an electronic device according to some embodiments of the present application.

[0107] like Fig. 9 As shown, the electronic device includes: at least one processor 901, at least one communication interface 902, at least one memory 903 and at least one communication bus 904; optionally, the communication interface 902 may be an interface of a communication module, such as an interface of a GSM module; the processor 901 may be a processor CPU, or an application-specific integrated circuit ASIC (Application Specific Integrated Circuit), or one or more integrated circuits configured to implement the embodiments of the present invention. The memory 903 may include a high-speed RAM memory, and may also include a non-volatile memory (non-volatile memory), such as at least one disk storage. Among them, the memory 903 stores a program, and the processor 901 calls the program stored in the memory 903 to execute part or all of the above-mentioned method embodiments.

[0108] The present application relates to a storage medium for storing a computer-readable program. When the computer-readable program is executed, part or all of the above-mentioned method embodiments are executed.

[0109] Alternatively, the storage medium may be a non-transitory computer-readable storage medium, for example, the non-transitory computer-readable storage medium may be a ROM, a random access memory (RAM), a CD-ROM, a magnetic tape, a floppy disk, an optical data storage device, and the like.

[0110] Based on the same inventive concept, an embodiment of the present application further provides a computer program product, including a computer program, which implements part or all of the above-mentioned method embodiments when executed by a processor.

[0111] The basic concepts have been described above. Obviously, for those skilled in the art, the above detailed disclosure is only for example and does not constitute a limitation of the present application. Although not explicitly stated herein, those skilled in the art may make various modifications, improvements and amendments to the present application. Such modifications, improvements and amendments are suggested in the present application, so such modifications, improvements and amendments still belong to the spirit and scope of the exemplary embodiments of the present application.

[0112] At the same time, the present application uses specific words to describe the embodiments of the present application. For example, "one embodiment", "an embodiment", and / or "some embodiments" refer to a certain feature, structure or characteristic related to at least one embodiment of the present application. Therefore, it should be emphasized and noted that "one embodiment" or "an embodiment" or "an alternative embodiment" mentioned twice or multiple times in different positions in the present application does not necessarily refer to the same embodiment. In addition, some features, structures or characteristics in one or more embodiments of the present application can be appropriately combined.

[0113] In addition, unless explicitly stated in the claims, the order of the processing elements and sequences described in this application, the use of alphanumeric characters, or the use of other names are not intended to limit the order of the processes and methods of this application. Although the above disclosure discusses some invention embodiments that are currently considered useful through various examples, it should be understood that such details are only for illustrative purposes, and the attached claims are not limited to the disclosed embodiments. On the contrary, the claims are intended to cover all modifications and equivalent combinations that are consistent with the essence and scope of the embodiments of this application. For example, although the system components described above can be implemented by hardware devices, they can also be implemented only by software solutions, such as installing the described system on an existing server or mobile device.

[0114] Similarly, it should be noted that in order to simplify the description of the disclosure of this application and thus help understand one or more embodiments of the invention, in the above description of the embodiments of this application, multiple features are sometimes combined into one embodiment, figure or description thereof. However, this disclosure method does not mean that the features required by the object of this application are more than the features mentioned in the claims. In fact, the features of the embodiments are less than all the features of the single embodiment disclosed above.

[0115] In some embodiments, numbers describing the number of components and attributes are used. It should be understood that such numbers used in the description of the embodiments are modified by the modifiers "about", "approximately" or "substantially" in some examples. Unless otherwise specified, "about", "approximately" or "substantially" indicate that the numbers are allowed to vary by ±20%. Accordingly, in some embodiments, the numerical parameters used in the specification and claims are approximate values, which may change according to the required features of individual embodiments. In some embodiments, the numerical parameters should take into account the specified significant digits and adopt the general method of retaining digits. Although the numerical domains and parameters used to confirm the breadth of their range in some embodiments of the present application are approximate values, in specific embodiments, the setting of such numerical values ​​is as accurate as possible within the feasible range.

[0116] Each patent, patent application, patent application disclosure, and other materials, such as articles, books, instructions, publications, documents, etc., cited in this application are hereby incorporated by reference in their entirety. Except for application history documents that are inconsistent with or conflicting with the content of this application, documents that limit the broadest scope of the claims of this application (currently or later attached to this application) are also excluded. It should be noted that if the descriptions, definitions, and / or use of terms in the attached materials of this application are inconsistent or conflicting with the content described in this application, the descriptions, definitions, and / or use of terms in this application shall prevail.

[0117] Finally, it should be understood that the embodiments described in this application are only used to illustrate the principles of the embodiments of the present application. Other variations may also fall within the scope of the present application. Therefore, as an example and not a limitation, the alternative configurations of the embodiments of the present application may be considered to be consistent with the teachings of the present application. Accordingly, the embodiments of the present application are not limited to the embodiments explicitly introduced and described in the present application.

Claims

1. A method for determining the amount of gas injected into a single well to displace top attic oil, characterized in that: The method comprises: Using the established simplified reservoir model, the rock volume of the target gas injection well above the oil-gas interface depth is obtained; The average porosity calculation formula is used to obtain the average porosity of the rock above the oil-gas interface of the target gas injection well; Using a gas saturation calculation formula, the gas saturation of the gas cap area above the oil-gas interface of the target gas injection well is obtained; Using the deviation factor chart, the expansion coefficient of the crude oil in the target gas injection well under the current reservoir formation pressure and the current reservoir temperature is obtained; An upper limit value of the gas injection amount of the target gas injection well is calculated based on the rock volume, the average porosity of the rock, the gas saturation of the gas cap zone, and the expansion coefficient.

2. The method according to claim 1, characterized in that: The simplified reservoir model is a conical solid geometric model; The established simplified reservoir model is used to obtain the rock volume of the target gas injection well above the oil-gas interface depth, including: Dividing the simplified reservoir model into a plurality of differential units from top to bottom in sequence; wherein the first differential unit is a cone structure, and the remaining differential units are truncated cone structures; For the multiple differential units, the rock volume V of the target gas injection well above the oil-gas interface depth is calculated using the following formula: Among them, s1 is the bottom area of ​​the first differential unit; h is the elevation value; s i is the bottom area of ​​the ith differential unit.

3. The method according to claim 1, characterized in that The average porosity calculation formula is as follows: in, is the average porosity of the rock; N is the attic oil reserves to be displaced; B O is the volume coefficient; V1 is the rock volume above the original oil-water interface of the target gas injection well; S O is the oil saturation; ρ is the crude oil density.

4. The method according to claim 1, characterized in that: The gas saturation calculation formula is as follows: S g =(1-S wi -S or )×100% Among them, S g is the gas saturation of the gas cap zone; S wi is the bound water saturation; S or is the residual oil saturation.

5. The method according to claim 1, characterized in that The method of using the deviation factor chart to obtain the expansion coefficient of the crude oil in the target gas injection well at the current reservoir formation pressure and the current reservoir temperature includes: Using the deviation factor chart, the deviation factor corresponding to the current reservoir formation pressure and the current reservoir temperature is obtained; The expansion coefficient is obtained by using the deviation factor, the current reservoir formation pressure and the current reservoir temperature of the target gas injection well through the following calculation formula: Among them, E g is the expansion coefficient; Z is the deviation factor; T is the current reservoir temperature; and P is the current reservoir formation pressure.

6. The method according to claim 1, characterized in that The upper limit of the gas injection volume of the target gas injection well is calculated according to the following formula: Wherein, G is the upper limit of the gas injection volume of the target gas injection well; V is the rock volume above the oil-gas interface depth, m 3 ; is the average porosity; S g is the gas saturation of the gas cap zone; E g is the expansion coefficient.

7. A device for determining the amount of gas injected into a single well to displace top attic oil, characterized in that: The device comprises: The first acquisition module is used to obtain the rock volume of the target gas injection well above the oil-gas interface depth by using the established simplified reservoir model; The second acquisition module is used to obtain the average porosity of the rock above the oil-gas interface of the target gas injection well by using the average porosity calculation formula; The third acquisition module is used to obtain the gas saturation of the gas cap area above the oil-gas interface of the target gas injection well by using a gas saturation calculation formula; A fourth acquisition module is used to obtain the expansion coefficient of the crude oil in the target gas injection well under the current reservoir formation pressure and the current reservoir temperature by using the deviation factor map; The fifth acquisition module is used to calculate the upper limit of the gas injection volume of the target gas injection well according to the rock volume, the average porosity of the rock, the gas saturation of the gas cap zone and the expansion coefficient.

8. The device according to claim 7, characterized in that The simplified reservoir model is a conical solid geometric model; The established simplified reservoir model is used to obtain the rock volume of the target gas injection well above the oil-gas interface depth, including: Dividing the simplified reservoir model into a plurality of differential units from top to bottom in sequence; wherein the first differential unit is a cone structure, and the remaining differential units are truncated cone structures; For the multiple differential units, the rock volume V of the target gas injection well above the oil-gas interface depth is calculated using the following formula: Among them, s1 is the bottom area of ​​the first differential unit; h is the elevation value; s i is the bottom area of ​​the ith differential unit.

9. An electronic device, comprising a memory and a processor, wherein the memory stores a computer program, and the processor executes the method according to any one of claims 1 to 6 when running the program.

10. A storage medium for storing a computer-readable program, wherein when the computer-readable program is executed, the method according to any one of claims 1 to 6 is executed.

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