Method and device for determining oil reservoir intermittent steam injection period, medium and electronic equipment

Abstract

The invention discloses a method and device for determining an oil reservoir intermittent steam injection period, a medium and electronic equipment. The method comprises the steps that the well shut-in time and the bottom hole pressure of an oil well are obtained, and correlation of the well shut-in time and the bottom hole pressure is achieved; acquiring a shut-in pressure curve and a bottom hole pressure curve according to geological characteristics and development characteristics of the oil reservoir; and according to the well shut-in time, the well shut-in pressure curve and the bottom hole pressure curve, the intermittent steam injection period of the oil reservoir is calculated. According to the technical scheme, the huff-puff oil-gas ratio of the oil reservoir can be increased.

Description

Technical Field

[0001] The present application belongs to the technical field of oil extraction, and in particular relates to a method, device, medium and electronic equipment for determining an intermittent steam injection period of an oil reservoir. Background Art

[0002] At present, the main development contradictions faced by thermal recovery heavy oil reservoirs in the late stage of development are: first, the energy consumption of the huff-and-puff development formation is large, and the block is at a relatively low pressure level. Second, it is in the late stage of huff-and-puff development, and the continuous steam injection cycle has low oil production, low oil-gas ratio, and poor economic benefits. Third, the degree of mobilization is high, and the effect of measures to tap potential is poor. Fourth, development adjustment is difficult. Fifth, the primary oil production is nearing the end, and there is no suitable development successor technology.

[0003] Generally, there are three main technical means to improve the oil-gas ratio in heavy oil reservoirs: optimizing the steam injection method, optimizing the steam injection string, and optimizing the steam injection parameters. Optimizing the steam injection method refers to stratified steam injection, combined steam injection, and multi-point steam injection in horizontal wells; optimizing the steam injection string refers to achieving uniform utilization of the oil layer through the optimized design of the steam injection string; optimizing the steam injection parameters refers to optimizing the design of key parameters such as steam injection intensity, steam injection speed, and steam injection dryness. However, for thermal recovery heavy oil reservoirs that are already in the late stage of development, the effect of improving the oil-gas ratio by the above methods is getting worse and worse.

[0004] After consulting the Chinese patent CN201610274602.5 "A chart method for judging the optimal timing of steam injection in heavy oil thermal recovery wells", the method described can judge the timing of the rotation according to the chart position of the oil well production liquid and water content. However, for heavy oil wells with low pressure and low production at the end of development, this timing judgment method is limited and cannot solve the relationship between bottom hole pressure recovery and redistribution of oil saturation in the oil layer. In addition, the continuous throughput oil-gas ratio is low and the economic benefit is poor.

[0005] Therefore, the present application provides a method for determining the intermittent steam injection period of an oil reservoir to improve the throughput oil-steam ratio of the oil reservoir. Summary of the invention

[0006] The embodiments of the present application provide a method, device, medium and electronic device for determining the intermittent steam injection period of an oil reservoir, wherein the method can improve the throughput oil-steam ratio of the oil reservoir.

[0007] Other features and advantages of the present application will become apparent from the following detailed description, or may be learned in part by the practice of the present application.

[0008] According to a first aspect of an embodiment of the present application, a method for determining an intermittent steam injection period of an oil reservoir is provided, characterized in that the method comprises: correlating the shut-in time and the bottom hole pressure of the oil well by acquiring the shut-in time and the bottom hole pressure of the oil well; acquiring a shut-in pressure curve and a bottom hole pressure curve according to geological characteristics and development characteristics of the oil reservoir; and calculating the intermittent steam injection period of the oil reservoir according to the shut-in time, the shut-in pressure curve, and the bottom hole pressure curve.

[0009] In some embodiments of the present application, based on the above scheme, the following formula is introduced to realize the correlation between the shut-in time and the bottom hole pressure:

[0010]

[0011] Among them, p ws is the bottom hole pressure, p i is the original formation pressure, t p is the well opening time, Δt s It is the time to shut down the well.

[0012] In some embodiments of the present application, based on the aforementioned scheme, in the northern area of ​​the reservoir and when the well is shut-in for 3 to 5 days, the bottom hole pressure is restored to 1.5 MPa to 2.0 MPa.

[0013] In some embodiments of the present application, based on the above scheme, in the southern area of ​​the reservoir and when the well is shut in for 3 to 5 days, the bottom hole pressure is restored to 0.9-1.6 MPa.

[0014] In some embodiments of the present application, based on the aforementioned scheme, the method further includes: obtaining the crude oil viscosity of the current reservoir, and analyzing the correlation between the pressure recovery rate of the reservoir and the crude oil viscosity based on the crude oil viscosity, so as to determine the intermittent steam injection cycle of the reservoir.

[0015] In some embodiments of the present application, based on the aforementioned solution, when the crude oil viscosity is less than 10000 MPa.s, the oil well is shut down for 12 months and the bottom hole pressure is restored to 2.5 MPa.

[0016] In some embodiments of the present application, based on the aforementioned scheme, when the crude oil viscosity is greater than 10,000 MPa.s and the crude oil viscosity is less than 20,000 MPa.s, the oil well is shut down for 24 months and the bottom hole pressure is restored to 2.5 MPa.

[0017] Compared with the prior art, the present invention has at least the following beneficial effects:

[0018] This application analyzes the structure and characteristics of the oil reservoir, and uses the pressure drop funnel principle to obtain the shut-in time and bottom hole pressure of the oil well, thereby realizing the correlation between the shut-in time and the bottom hole pressure. After knowing the relationship between the shut-in time and the bottom hole pressure of the oil well in the oil reservoir, the shut-in pressure curve and the bottom hole pressure curve of the oil well are obtained according to the geological characteristics and development characteristics of the oil reservoir, and the method of selecting oil wells for measurement by zoning. According to the shut-in time, shut-in pressure curve, and bottom hole pressure curve, the intermittent steam injection cycle of the oil reservoir is calculated.

[0019] In addition, in the process of calculating the intermittent steam injection cycle of the reservoir, the current crude oil viscosity of the reservoir can be obtained, and based on the crude oil viscosity, the correlation between the pressure recovery rate of the reservoir and the crude oil viscosity can be analyzed to determine the intermittent steam injection cycle of the reservoir.

[0020] Based on the above method, the method for determining the intermittent steam injection period of an oil reservoir provided by the present invention can improve the accuracy of calculating the intermittent steam injection period of an oil reservoir, thereby improving the oil-steam ratio during the development of the oil reservoir.

[0021] According to the second aspect of an embodiment of the present application, a device for determining the intermittent steam injection period of an oil reservoir is provided, characterized in that the device comprises: a correlation unit for correlating the shut-in time with the bottom hole pressure based on the Horner formula; an acquisition unit for acquiring a shut-in pressure curve and a bottom hole pressure curve according to the geological characteristics and development characteristics of the oil reservoir; and a calculation unit for calculating the intermittent steam injection period of the oil reservoir according to the shut-in time, the shut-in pressure curve, and the bottom hole pressure curve.

[0022] According to a third aspect of an embodiment of the present application, a computer-readable storage medium is provided, characterized in that at least one program code is stored in the computer-readable storage medium, and the at least one program code is loaded and executed by a processor to implement the operations performed by the described method.

[0023] According to a fourth aspect of an embodiment of the present application, an electronic device is provided, characterized in that the electronic device includes one or more processors and one or more memories, at least one program code is stored in the one or more memories, and the at least one program code is loaded and executed by the one or more processors to implement the operations performed by the method.

[0024] The beneficial effects of each embodiment of the second to fourth aspects mentioned above can refer to the beneficial effects of the first aspect and each embodiment of the first aspect mentioned above, and will not be repeated here.

[0025] It should be understood that the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] The drawings herein are incorporated into the specification and constitute a part of the specification, showing embodiments consistent with the present application, and together with the specification, are used to explain the principles of the present application. Obviously, the drawings described below are only some embodiments of the present application, and for ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work. In the drawings:

[0027] Figure 1 A flow chart showing a method for determining an intermittent steam injection cycle of an oil reservoir in an embodiment of the present application is shown;

[0028] Figure 2 A relationship diagram between the shutdown time and the throughput oil-gas ratio of the northern part of the reservoir in the embodiment of the present application is shown;

[0029] Figure 3 A relationship diagram between the shutdown time and the throughput oil-gas ratio of the southern part of the oil reservoir in the embodiment of the present application is shown;

[0030] Figure 4 A schematic diagram of the structure of a device for determining an intermittent steam injection cycle of an oil reservoir in an embodiment of the present application is shown;

[0031] Figure 5 A schematic diagram of the structure of an electronic device in an embodiment of the present application is shown. DETAILED DESCRIPTION

[0032] 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.

[0033] In addition, described feature, structure or characteristic can be combined in one or more embodiments in any suitable manner. In the following description, many specific details are provided to provide a full understanding of the embodiments of the present application. However, those skilled in the art will appreciate that the technical scheme of the present application can be put into practice without one or more of the specific details, or other methods, components, devices, steps, etc. can be adopted. In other cases, known methods, devices, realizations or operations are not shown or described in detail to avoid blurring the various aspects of the application.

[0034] The block diagrams shown in the accompanying drawings are merely functional entities and do not necessarily correspond to physically independent entities. That is, these functional entities may be implemented in software form, or in one or more hardware modules or integrated circuits, or in different networks and / or processor devices and / or microcontroller devices.

[0035] The flowcharts shown in the accompanying drawings are only exemplary and do not necessarily include all the contents and operations / steps, nor must they be executed in the order described. For example, some operations / steps can be decomposed, and some operations / steps can be combined or partially combined, so the actual execution order may change according to actual conditions.

[0036] The following is a detailed description of this application:

[0037] Figure 1 The flowchart of the method for determining the intermittent steam injection period of the oil reservoir in the embodiment of the present application is shown. The method for determining the intermittent steam injection period of the oil reservoir can be executed by a device with a computing and processing function, for example, it can be executed by a device for determining the intermittent steam injection period of the oil reservoir. Figure 1 As shown, the method for determining the intermittent steam injection period of the oil reservoir includes at least steps 110 to 130, which are described in detail as follows:

[0038] Step 110, by acquiring the shut-in time and the bottom hole pressure of the oil well, the shut-in time and the bottom hole pressure are associated with each other.

[0039] Step 120, obtaining a shut-in pressure curve and a bottom hole pressure curve according to the geological characteristics and development characteristics of the oil reservoir.

[0040] Step 130, calculating the intermittent steam injection period of the oil reservoir according to the shut-in time, the shut-in pressure curve, and the bottom hole pressure curve.

[0041] In this application, the throughput development of heavy oil reservoirs is itself a depletion development method. Since heavy oil and extra-heavy oil have high viscosity and large flow resistance, after multiple rounds of throughput, as the recovery degree increases, the formation deficit increases, the oil layer pressure decreases, and a large pressure drop funnel is formed near the wellbore, thereby reducing the driving pressure difference of the reservoir and resulting in low continuous throughput capacity of the oil well.

[0042] Through theoretical analysis and practical exploration, the principle of pressure drop funnel can be used to determine the intermittent steam injection cycle of the reservoir, thereby rationally optimizing the steam injection cycle, redistributing the oil saturation in the oil layer, restoring the bottom hole pressure level, reducing the pressure drop funnel, increasing the production pressure difference, and thus overcoming the oil flow start-up pressure difference, improving the oil well production capacity and the throughput oil-steam ratio.

[0043] Based on the above analysis and derivation process, the shut-in time and bottom hole pressure of the oil well are obtained based on the pressure drop funnel principle to achieve the correlation between the shut-in time and the bottom hole pressure.

[0044] Furthermore, in the embodiment of the present application, the following formula is introduced to realize the correlation between the shut-in time and the bottom hole pressure:

[0045]

[0046] Among them, p ws is the bottom hole pressure, p i is the original formation pressure, t p is the well opening time, Δt s It is the time to shut down the well.

[0047] Then, according to the geological characteristics and development characteristics of the reservoir, the shut-in pressure curve and bottom hole pressure curve can be obtained by selecting typical wells in different areas. According to the shut-in time, shut-in pressure curve, and bottom hole pressure curve, the intermittent steam injection cycle of the reservoir can be calculated.

[0048] Specifically, since the development efficiency of different regions is different, and the levels of formation pressure drop are also different, the shut-in pressure curve and the bottom hole pressure curve can be obtained according to different regions.

[0049] For example, in the northern area of ​​the reservoir and when the well is shut in for 3 to 5 days, the bottom hole pressure is restored to 1.5 MPa to 2.0 MPa.

[0050] For example, in the southern area of ​​the reservoir, when the well was shut in for 3 to 5 days, the bottom hole pressure recovered to 0.9-1.6 MPa.

[0051] In addition, the intermittent steam injection cycle of the reservoir will also be affected by the viscosity of the crude oil in the reservoir. For example, when the crude oil viscosity is less than 10,000 mpa.s, the oil well is shut down for 12 months, and the bottom hole pressure is restored to 2.5 MPa. For another example, when the crude oil viscosity is greater than 10,000 mpa.s and the crude oil viscosity is less than 20,000 mpa.s, the oil well is shut down for 24 months, and the bottom hole pressure is restored to 2.5 MPa.

[0052] Therefore, the intermittent steam injection cycle of the reservoir can be determined by obtaining the crude oil viscosity of the current reservoir and analyzing the correlation between the pressure recovery rate of the reservoir and the crude oil viscosity based on the crude oil viscosity.

[0053] After determining the intermittent steam injection cycle of the reservoir, the practicability of the intermittent steam injection cycle can be tested based on the actual development situation of the reservoir.

[0054] Reference Figure 2 , shows the relationship between the shutdown time and the throughput oil-gas ratio in the northern part of the reservoir in the embodiment of the present application. Figure 2 It can be learned that Figure 2 There are 32 wells with medium intermittent period longer than 12 months, the steam injection pressure increased by 1.36MPa, the periodic oil production increased by 270t-330t, the periodic average daily oil production increased by 0.9t, and the periodic oil-steam ratio increased by 0.11-0.15.

[0055] Reference Figure 3 , shows the relationship between the shutdown time and the throughput oil-gas ratio in the southern part of the reservoir in the embodiment of the present application. Figure 2 It can be learned that Figure 2 There are 19 wells with medium intermittent periods longer than 24 months. The average steam injection pressure increased by 1.36MPa, the average oil production increased by 146t, the average daily oil production increased by 0.21t-0.57t, and the oil-steam ratio increased by 0.06-0.08.

[0056] Based on the same inventive concept, the present application also provides a device for determining the intermittent steam injection period of an oil reservoir, referring to Figure 4 , showing a schematic diagram of the structure of the device for determining the intermittent steam injection cycle of the oil reservoir in the embodiment of the present application. The device 400 for determining the intermittent steam injection cycle of the oil reservoir comprises: a correlation unit 401, used to correlate the shut-in time with the bottom hole pressure based on the Horner formula; an acquisition unit 402, used to acquire the shut-in pressure curve and the bottom hole pressure curve according to the geological characteristics and development characteristics of the oil reservoir; and a calculation unit 403, used to calculate the intermittent steam injection cycle of the oil reservoir according to the shut-in time, the shut-in pressure curve, and the bottom hole pressure curve.

[0057] For details not disclosed in the embodiments of the device of the present application, please refer to the embodiments of the above method of the present application.

[0058] Based on the same inventive concept, the present application may also provide a computer-readable storage medium, characterized in that at least one program code is stored in the computer-readable storage medium, and the at least one program code is loaded and executed by a processor to implement the operations performed by the method described.

[0059] Based on the same inventive concept, the present application also provides an electronic device, referring to Figure 5 , Figure 5 A schematic diagram of the structure of an electronic device in an embodiment of the present application is shown.

[0060] The electronic device includes one or more memories 504, one or more processors 502, and at least one computer program (program code) stored in the memory 504 and executable on the processor 502. When the processor 502 executes the computer program, the method described above is implemented.

[0061] Among them, Figure 5In the embodiment of the present invention, a bus architecture (represented by bus 500) is shown, which may include any number of interconnected buses and bridges, and bus 500 links various circuits including one or more processors represented by processor 502 and memory represented by memory 504. Bus 500 may also link various other circuits such as peripherals, voltage regulators, and power management circuits, which are well known in the art and are therefore not further described herein. Bus interface 505 provides an interface between bus 500 and receiver 501 and transmitter 503. Receiver 501 and transmitter 503 may be the same element, namely a transceiver, providing a unit for communicating with various other devices over a transmission medium. Processor 502 is responsible for managing bus 500 and general processing, while memory 504 may be used to store data used by processor 502 when performing operations.

[0062] The functions described herein may be implemented in hardware, software executed by a processor, firmware, or any combination thereof. If implemented in software executed by a processor, the functions may be stored as one or more instructions or codes on a computer-readable medium or transmitted via a computer-readable medium. Other examples and implementations are within the scope and spirit of the present application and the appended claims. For example, due to the nature of software, the functions described above may be implemented using software executed by a processor, hardware, firmware, hard wiring, or a combination of any of these. In addition, each functional unit may be integrated into a processing unit, each unit may exist physically separately, or two or more units may be integrated into one unit.

[0063] In the several embodiments provided in this application, it should be understood that the disclosed technical content can be implemented in other ways. Among them, the device embodiments described above are only schematic. For example, the division of the units can be a logical function division. There may be other division methods in actual implementation. For example, multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be through some interfaces, indirect coupling or communication connection of units or modules, which can be electrical or other forms.

[0064] The units described as separate components may or may not be physically separated, and the components of the control device may or may not be physical units, that is, they may be located in one place or distributed in multiple units. Some or all of the units may be selected according to actual needs to achieve the purpose of the present embodiment.

[0065] If the integrated unit is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present application, in essence, or the part that contributes to the prior art or all or part of the technical solution can be embodied in the form of a software product, and the computer software product is stored in a storage medium, including a number of instructions to enable a computer device (which can be a personal computer, a server or a network device, etc.) to perform all or part of the steps of the method described in each embodiment of the present application. The aforementioned storage medium includes: U disk, read-only memory (ROM, Read-Only Memory), random access memory (RAM, Random Access Memory), mobile hard disk, disk or optical disk and other media that can store program codes.

[0066] The above description is only an embodiment of the present application and is not intended to limit the present application. For those skilled in the art, the present application may have various modifications and variations. Any modification, equivalent substitution, improvement, etc. made within the spirit and principle of the present application shall be included in the scope of the claims of the present application.

Claims

1. A method for determining the intermittent steam injection period of an oil reservoir, characterized in that: The method comprises: By acquiring the shut-in time and the bottom hole pressure of the oil well, the shut-in time and the bottom hole pressure are associated with each other; Obtain shut-in pressure curve and bottom hole pressure curve according to the geological characteristics and development characteristics of the reservoir; The intermittent steam injection period of the oil reservoir is calculated according to the shut-in time, the shut-in pressure curve, and the bottom hole pressure curve.

2. The method according to claim 1, characterized in that The following formula is used to realize the correlation between the shut-in time and the bottom hole pressure: Among them, p ws is the bottom hole pressure, p i is the original formation pressure, t p is the well opening time, Δt s It is the time to shut down the well.

3. The method according to claim 2, characterized in that In the northern area of ​​the reservoir and when the well was shut-in for 3 to 5 days, the bottom hole pressure recovered to 1.5 MPa to 2.0 MPa.

4. The method according to claim 2, characterized in that: In the southern area of ​​the reservoir and when the well was shut-in for 3 to 5 days, the bottom hole pressure recovered to 0.9 to 1.6 MPa.

5. The method according to claim 1, characterized in that The method further comprises: The crude oil viscosity of the current oil reservoir is obtained, and based on the crude oil viscosity, the correlation between the pressure recovery rate of the oil reservoir and the crude oil viscosity is analyzed, so as to determine the intermittent steam injection cycle of the oil reservoir.

6. The method according to claim 5, characterized in that When the crude oil viscosity is less than 10000 MPa.s, the oil well will be shut down for 12 months and the bottom hole pressure will be restored to 2.5 MPa.

7. The method according to claim 5, characterized in that When the crude oil viscosity is greater than 10,000 MPa.s and less than 20,000 MPa.s, the oil well will be shut down for 24 months and the bottom hole pressure will be restored to 2.5 MPa.

8. A device for determining the intermittent steam injection period of an oil reservoir, characterized in that: The device comprises: A correlation unit for correlating the shut-in time with the bottom hole pressure based on Horner's formula; An acquisition unit, used for acquiring a shut-in pressure curve and a bottom hole pressure curve according to geological characteristics and development characteristics of the oil reservoir; The calculation unit is used to calculate the intermittent steam injection period of the oil reservoir according to the shut-in time, the shut-in pressure curve, and the bottom hole pressure curve.

9. A computer-readable storage medium, characterized in that: The computer-readable storage medium stores at least one program code, and the at least one program code is loaded and executed by a processor to implement the operations performed by the method according to any one of claims 1 to 7.

10. An electronic device, characterized in that: The electronic device includes one or more processors and one or more memories, wherein the one or more memories store at least one program code, and the at least one program code is loaded and executed by the one or more processors to implement the operations performed by the method according to any one of claims 1 to 7.

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