Method and device for extracting liquid and selecting well after single-well high-water flooding of large-bottom-water reservoir

Abstract

The invention discloses a method and a device for extracting and selecting a well after single-well high-water flooding of a large-bottom-water reservoir, and belongs to the technical field of extracting and selecting the well. The liquid extraction well selection method comprises the following steps: obtaining a liquid extraction well selection standard and dividing a remaining recoverable reserve standard; the single wells reaching the remaining recoverable reserve standard in the target oil reservoir are preliminarily screened, and preliminary target wells are obtained; and the reservoir condition, the interlayer condition and the moisture content condition of the preliminary target well are obtained and compared with the liquid extraction well selection standard, under the condition that the liquid extraction well selection standard is met, the preliminary target well can conduct liquid extraction, well selection is conducted through the clear liquid extraction well selection standard, the liquid extraction effect is optimized, and the expected target is achieved.

Description

Technical Field

[0001] This invention belongs to the field of oilfield production and gas extraction technology, specifically relating to a method and device for selecting wells after high water flooding in a single well in a large bottom water reservoir. Background Technology

[0002] Currently, most oilfields have entered the medium-to-high water-cut stage, posing significant challenges to oilfield development. Bottom-water reservoirs, in particular, are prone to bottom-water coning due to their large bottom water volume and abundant natural energy. Bottom-water coning is a common and intractable problem in bottom-water reservoir production, leading to water flooding of the oil layer and severely impacting production. During production, the significant pressure drop near the wellbore causes deformation of the oil-water interface in bottom-water reservoirs, resulting in a conical rise and further exacerbating the bottom-water coning phenomenon.

[0003] The bottom water coning phenomenon in bottom water reservoirs brings many adverse consequences to oilfield development. It increases the water cut of oil wells, causing premature water breakthrough and a rapid decline in production. Furthermore, the reduced oil recovery rate leads to a decrease in the efficiency of oilfield development. This not only increases the cost of oilfield development but also affects the long-term development of the oilfield.

[0004] For high water cut in single wells, oilfields conventionally address the issue through measures such as water shut-off, perforation modification, and fluid extraction. However, from an implementation perspective, fluid extraction is simpler, requires less investment, and offers higher economic benefits. Nevertheless, even after fluid extraction is completed using existing techniques, a significant portion of oil and gas can still be extracted from the extracted well, indicating remaining potential for further extraction. This suggests that current fluid extraction methods have not achieved their intended goals.

[0005] The reason for this is that there is currently no unified and clear standard for selecting wells for fluid extraction. This leads to subjectivity and randomness in the selection of wells, which in turn affects the stability and predictability of the extraction effect. In order to optimize the extraction effect and achieve the expected goals, it is necessary to conduct in-depth research and formulate scientific and reasonable standards for selecting wells for fluid extraction. Summary of the Invention

[0006] The purpose of this invention is to provide a method and apparatus for selecting a single well in a large bottom water reservoir after high water flooding, in order to solve the technical problem of poor fluid extraction effect caused by the lack of clear existing standards for selecting a well for fluid extraction.

[0007] To achieve the above objectives, the present invention employs the following technical solution:

[0008] This invention provides a method for selecting a well after high water flooding in a single well in a large-bottom-water reservoir, comprising the following steps:

[0009] Obtain the selection criteria for extraction wells and delineate the remaining recoverable reserves;

[0010] Preliminary screening of single wells within the target reservoir that meet the standard for remaining recoverable reserves yields preliminary target wells.

[0011] Obtain information on the reservoir, interlayers, and water cut of the preliminary target well, and compare it with the selection criteria for fluid extraction wells. If the selection criteria for fluid extraction wells are met, the preliminary target well can be used for fluid extraction.

[0012] In the specific implementation process, the selection criteria for the extraction wells include the water cut standard, the reservoir standard, and the interlayer standard.

[0013] In the specific implementation process, the water cut standard of the extraction well is a water cut between 90% and 94%.

[0014] In the specific implementation process, the process of obtaining the water cut standard of the extraction well is as follows:

[0015] The extraction ratio and timing of the maximum extraction and oil production of a single well in the target reservoir are predicted by reservoir numerical simulation. Based on the extraction ratio and timing of the maximum extraction and oil production, the water cut standard of the extraction well is obtained.

[0016] In the specific implementation process, the reservoir standards for the fluid extraction wells are as follows:

[0017] The reservoir is a positive rhythmic reservoir, and the permeability difference between the upper and lower parts of the reservoir is greater than 10.

[0018] In the specific implementation process, the interlayer standard for the fluid extraction well is as follows:

[0019] The thickness of the interlayer is greater than 2m, and the main properties of the interlayer are argillaceous interlayer or calcareous interlayer.

[0020] In the specific implementation process, the process of obtaining the reservoir standard and the interlayer standard of the fluid extraction well is as follows:

[0021] Based on reservoir characteristic analysis, fluid extraction and oil production mechanism, and comparison with actual oilfield production data, reservoir standards and interlayer standards for fluid extraction wells were obtained.

[0022] In the specific implementation process, the standard for remaining recoverable reserves is that the remaining recoverable reserves are greater than 10,000 tons.

[0023] In the specific implementation process, the process of obtaining the remaining recoverable reserves standard is as follows:

[0024] The standard for remaining recoverable reserves is obtained based on the proportion of economically recoverable reserves, the cost of liquid extraction, and the production increase effect after liquid extraction.

[0025] This invention also provides a well selection device for high water flooding followed by fluid extraction in a single well in a large bottom water reservoir, comprising:

[0026] The standard acquisition module is used to acquire the selection criteria for liquid extraction wells and classify the remaining recoverable reserves criteria.

[0027] The screening module is used to initially screen single wells in the target reservoir that meet the standard of remaining recoverable reserves, and to obtain preliminary target wells.

[0028] The discrimination module is used to obtain the reservoir conditions, interlayer conditions and water cut of the preliminary target well, and compare them with the selection criteria for liquid extraction wells. If the selection criteria for liquid extraction wells are met, the preliminary target well can be used for liquid extraction.

[0029] The present invention also provides an electronic device, the electronic device comprising: at least one processor; and a memory communicatively connected to the at least one processor; wherein,

[0030] The memory stores a computer program that can be executed by the at least one processor, which enables the at least one processor to perform the above-described method for selecting wells after high water flooding in a single well in a large bottom water reservoir.

[0031] The present invention also provides a computer-readable storage medium storing computer instructions, which are used to cause a processor to execute the above-described method for selecting wells after high water flooding in a single well in a large bottom water reservoir.

[0032] Compared with the prior art, the present invention has the following beneficial effects:

[0033] This invention provides a method for selecting wells for fluid extraction after high water flooding in large-bottom-water oil reservoirs. First, by acquiring and applying selection criteria for fluid extraction wells, this method provides clear and specific guidance for the well selection process, effectively solving the problem of unclear existing selection criteria. Second, by defining standards for remaining recoverable reserves and initially screening wells that meet these standards, this method ensures that fluid extraction operations are concentrated on wells with greater potential, thereby optimizing oilfield resource utilization and improving extraction efficiency. Finally, based on the initial screening, further consideration is given to reservoir conditions, interlayer conditions, and water cut, and a comparison is made with the selection criteria for fluid extraction wells. This allows for a more comprehensive assessment of the extraction potential of individual wells, thereby improving the success rate and effectiveness of fluid extraction.

[0034] Furthermore, reservoir numerical simulation methods can reproduce the actual production dynamics of oilfields based on mathematical models, thereby accurately predicting the maximum fluid extraction and oil production increase of a single well and the timing of fluid extraction. By combining reservoir characteristic analysis, the fluid extraction and oil production increase mechanism, and comparison with actual oilfield production data, reservoir standards and interlayer standards for fluid extraction wells can be obtained more accurately. Based on the proportion of economically recoverable reserves, fluid extraction costs, and the production increase effect after fluid extraction, the obtained remaining recoverable reserve standards ensure the economic efficiency and effectiveness of well selection. These standards consider multiple aspects such as the water cut standard of the fluid extraction well, reservoir characteristics, and interlayer conditions, optimizing well selection criteria and improving the accuracy and efficiency of well selection. Using the above-mentioned fluid extraction well selection method, while considering economic benefits, maximizes the extension of the single-well oil production period, improves the single-well production effect, effectively increases the overall reservoir reserve utilization, and ultimately improves the recovery rate. Attached Figure Description

[0035] Figure 1 A flowchart of a method for selecting a single well in a large bottom water reservoir after high water flooding and fluid extraction is provided in an embodiment of the present invention;

[0036] Figure 2 A flowchart of a method for selecting a single well in a large-bottom-water reservoir after high water flooding and fluid extraction is provided for another embodiment of the present invention;

[0037] Figure 3 A diagram of a well selection device for high water flooding followed by fluid extraction in a single well of a large bottom water reservoir, provided in an embodiment of the present invention;

[0038] Figure 4 This is a core sample, test production data, and composite columnar section of a certain well.

[0039] Figure 5 Schematic diagram of the mechanism of liquid extraction and oil enhancement by interlayer shielding;

[0040] Figure 6 This is a comprehensive columnar section of the Triassic strata in a certain well;

[0041] Figure 7 The production curve of a well after fluid extraction measures;

[0042] Figure 8 The diagrams are schematic diagrams of the mechanism of liquid extraction and oil enhancement. Figure (a) is a schematic diagram before liquid extraction, and Figure (b) is a schematic diagram after liquid extraction.

[0043] Figure 9 Figure (a) shows the relationship between water cut and liquid production index, and Figure (b) shows the relationship between water cut increase rate.

[0044] Figure 10 Figure (a) shows the predicted extraction ratio, and Figure (b) shows the predicted extraction timing.

[0045] Figure 11 This is a schematic diagram of an electronic device provided according to an embodiment of the present invention.

[0046] Among them, 10-electronic device; 11-processor; 12-read-only memory; 13-random access memory; 14-bus; 15-I / O interface; 16-input unit; 17-output unit; 18-storage unit; 19-communication unit. Detailed Implementation

[0047] To enable those skilled in the art to better understand the present invention, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of the present invention.

[0048] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this invention are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of the invention described herein can be implemented in orders other than those illustrated or described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover a non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0049] The following is a further detailed description of this embodiment with reference to the accompanying drawings:

[0050] Taking the TⅢ oil group in the Santamu oilfield, a typical large-bottom-water reservoir, as an example, its water volume ratio is as high as 267 times. Through water flooding mode and based on the results of numerical simulation mechanism research, even after high water cut in a single well in the TⅢ oil group, a considerable portion of oil and gas can still be extracted through fluid extraction, demonstrating the potential and space for fluid extraction. The above results indicate that current fluid extraction methods have not yet achieved the target effect.

[0051] To address the technical problem of poor well extraction results caused by unclear existing standards for fluid extraction well selection, as described above, this embodiment provides a method, apparatus, electronic equipment, and computer program for fluid extraction well selection after high water flooding in a single well in a large bottom-water reservoir. For single wells after high water flooding, well selection is conducted based on the rhythmic characteristics of the reservoir, the distribution of interlayers, water cut changes, and reserve baseline. Through fluid extraction, the oil production period after high water flooding is further extended, and the single-well recovery rate is improved. Simultaneously, the increased fluid production leads to a further increase in water cut, which can be utilized on-site for Ordovician recharge, serving as an effective means of replenishing energy and displacing oil in the Ordovician system.

[0052] like Figure 1 As shown in one embodiment, a method for selecting a well after high water flooding in a single well in a large bottom water reservoir is provided, including the following steps:

[0053] S1: Obtain the selection criteria for liquid extraction wells and delineate the remaining recoverable reserves criteria;

[0054] S2: Initially screen single wells in the target reservoir that meet the standard of remaining recoverable reserves to obtain preliminary target wells;

[0055] S3: Obtain the reservoir conditions, interlayer conditions, and water cut of the preliminary target well, and compare them with the selection criteria for fluid extraction wells. If the selection criteria for fluid extraction wells are met, the preliminary target well can be used for fluid extraction.

[0056] In one embodiment, the selection criteria for extraction wells include the water cut standard, the reservoir standard, and the interlayer standard.

[0057] In this embodiment, the water cut standard for wells undergoing fluid extraction mainly refers to a threshold or range that the percentage of water by mass in the produced fluid should meet when selecting wells for fluid extraction operations. This standard is typically used to assess the water production status and development potential of oil wells to determine which wells are suitable for fluid extraction operations to increase production.

[0058] In this embodiment, the reservoir standard for fluid extraction wells mainly refers to a series of geological and physical property conditions or indicators that the reservoir in which the oil well is located should meet when selecting an oil well for fluid extraction operation.

[0059] In this embodiment, the interlayer standard for fluid extraction wells mainly refers to a series of conditions or indicators that the characteristics of the interlayer in the reservoir where the oil well is located should meet when selecting an oil well for fluid extraction operation.

[0060] In the specific implementation process, the water cut standard for the extraction well is that the water cut is between 90% and 94%; the reservoir standard for the extraction well is as follows: the reservoir is a positive rhythmic reservoir, and the permeability difference between the upper and lower parts of the reservoir is greater than 10; the interlayer standard is as follows: the thickness of the interlayer is greater than 2m, and the main properties of the interlayer are clay interlayer or calcareous interlayer; the remaining recoverable reserves standard is greater than 10,000 tons.

[0061] The standard for the water cut of a well is a water cut greater than 80%, with a preferred water cut greater than 90%, and a further water cut between 90% and 94%.

[0062] Specifically, the process of obtaining the water cut standard for extraction wells is as follows: the extraction ratio and extraction timing of the highest extraction and oil increase of a single well in the target reservoir are predicted by the reservoir numerical simulation method, and the water cut standard of the extraction well is obtained based on the extraction ratio and extraction timing of the highest extraction and oil increase.

[0063] Specifically, the process of obtaining the reservoir standard and interlayer standard for fluid extraction wells is as follows: Based on the reservoir characteristic analysis, the mechanism of fluid extraction and oil enhancement, and the comparison with actual oilfield production data, the reservoir standard and interlayer standard for fluid extraction wells are obtained.

[0064] Specifically, the process of obtaining the standard for remaining recoverable reserves is as follows: the standard for remaining recoverable reserves is obtained based on the proportion of economically recoverable reserves, the cost of liquid extraction, and the production increase effect after liquid extraction.

[0065] like Figure 2 As shown in one embodiment, a method for selecting a well for fluid extraction after high water flooding in a single well in a large bottom water reservoir is provided, as follows:

[0066] S01: Obtain the water cut standard, reservoir standard, interlayer standard, and remaining recoverable reserve standard for the extraction well:

[0067] The maximum fluid extraction and oil production increase of a single well in the target reservoir is predicted using reservoir numerical simulation methods, along with the optimal timing for fluid extraction. Based on this, the water cut standard for the extraction well is obtained. Reservoir and interlayer standards are also determined based on reservoir characteristic analysis, the mechanism of fluid extraction and oil production increase, and actual oilfield production data. Finally, the remaining recoverable reserves standard is obtained based on the proportion of economically recoverable reserves, extraction costs, and the production increase effect after extraction.

[0068] S02: Initially screen single wells in the target reservoir that meet the standard of remaining recoverable reserves to obtain preliminary target wells;

[0069] S03: Obtain the reservoir condition, interlayer condition, and water cut of the preliminary target well, and compare them with the reservoir condition, interlayer condition, and water cut standard of the liquid extraction well, respectively. Make a comprehensive judgment on whether the preliminary target well can be used for liquid extraction. If the liquid extraction well selection criteria are met, the preliminary target well can be used for liquid extraction.

[0070] The above-mentioned well selection criteria for single wells in the Dadishui oil reservoir after high water flooding are based on the well-controlled recoverable reserves, taking into account the changes in vertical permeability, the development of interlayer thickness, and the changes in water cut, etc., for comprehensive identification.

[0071] Table 1 Well Selection Criteria

[0072]

[0073]

[0074] As shown in Table 1, the degree of remaining oil enrichment is a key indicator for well selection. Based on the numerical simulation results, and taking into account the current oil price, the cost of fluid extraction measures, the average cumulative oil increase per well in fluid extraction wells, and the economic benefits, the well-controlled recoverable reserves limit is obtained. It is economically feasible to implement fluid extraction and oil increase for wells with well-controlled recoverable reserves greater than 10,000 tons.

[0075] like Figure 8 As shown in Figures (a) and (b), this embodiment describes well selection based on the fluid extraction mechanism. It describes a series of technical measures taken to improve fluid production and oil displacement efficiency when the water cut in the produced fluid of an oil well is high. The fluid extraction mechanism is as follows: In the high water cut stage, the oil well production decreases significantly due to factors such as decreased reservoir pressure, formation energy depletion, and uneven water flooding distribution within the reservoir. By amplifying the pressure difference for fluid extraction, firstly, a larger driving pressure difference can be established between the oil and water wells, overcoming the influence of capillary pressure, increasing the fluid supply radius, and improving the production index; secondly, after fluid extraction, as the production pressure difference increases, the previously undisturbed layers or even the untouched layers begin to supply fluid, resulting in a decrease in the water cut of the oil well. This is particularly pronounced for oil wells with multiple activated oil layers and significant inter-layer conflicts, where the increased production pressure difference after fluid extraction leads to a more significant decrease in water cut. By changing the production system and optimizing its operating parameters, the oil well production can be further increased, ultimately improving the overall recovery rate of the oilfield.

[0076] The standard for the water cut of a well for fluid extraction is a water cut between 90% and 94%, indicating a high to very high water cut period where the water cut has been stable for a long time and a water cone has been formed. For example... Figure 9 As shown in Figures (a) and (b), practice has shown that the rate of increase in water cut is inversely proportional to the water cut after 40% water cut. As the water cut increases, the rate of increase in water cut decreases significantly, and the liquid production index gradually increases. Especially after the water cut reaches more than 90%, the rate of change in water cut is much lower than the rate of change in the liquid production index, thus creating conditions for water-bearing oil production.

[0077] Furthermore, the specific process of predicting the maximum fluid extraction and oil increase ratio and extraction timing of a single well in the target reservoir using reservoir numerical simulation methods, and obtaining the water cut standard of the extraction well based on the maximum fluid extraction and oil increase ratio and extraction timing, is as follows:

[0078] like Figure 10 As shown in Figures (a) and (b), the extraction ratio and optimal timing were obtained: Based on numerical simulation studies, with a daily oil production of 50 t / d per well as a baseline, the production rate was increased by 2, 3, 4, 5, 6, 7, and 8 times respectively, until the water cut reached 98%. It was found that the oil increase was greatest when the extraction ratio was between 2 and 4 times. If the production rate is taken as the standard, considering a base production rate of 50 t / d, after the water cut reached 0%, 20%, 60%, 90%, and 98%, the production rate was increased to 200 t / d until the water cut reached 98%. The oil increase was highest when the water cut was around 60-90%.

[0079] like Figure 9 As shown, a feasibility analysis of fluid extraction was conducted: based on the core relative permeability curve, the relationship between water cut and fluid production index was analyzed. After the water cut reached 80%, the fluid production index increased rapidly with the increase of water cut, while the rate of increase in water cut changed relatively little, indicating that the Santamu Oilfield has room for fluid extraction and oil production. The production effect of single wells showed that after the water cut reached 90%, fluid extraction increased the fluid production from 60t / d to 105t / d, the fluid production intensity increased from 10m3 / (d·m) to 17.5m3 / (d·m), an increase of 75%, the water cut decreased to 88%, and the oil production increased from 6t / d to 13t / d, an increase of 117%.

[0080] This embodiment obtains the standard for remaining recoverable reserves based on the proportion of economically recoverable reserves, the cost of fluid extraction, and the production increase effect after fluid extraction; the standard for remaining recoverable reserves in the above fluid separation well method is that the remaining recoverable reserves are greater than 10,000 tons.

[0081] The process for obtaining the aforementioned standard for remaining recoverable reserves is as follows: A single well capable of extracting fluid still possesses a certain amount of recoverable reserves around its perimeter, providing a certain material basis. The presence of remaining oil and gas enrichment is the foundation and key to fluid extraction. Generally, the measure taken for single-well fluid extraction is to replace the pump with a larger displacement pump to meet higher fluid production demands. Replacing the pump with a larger one requires downhole operations. For example, due to the deep burial depth of the oil layers in the Santamu Oilfield, the difficulty and cost of the operation will increase accordingly. The cost of a single pump replacement operation is generally between 1.8 and 2 million yuan. While fluid extraction will increase oil production, the increase in total fluid volume will inevitably increase the cost of treating produced water, as well as the subsequent labor costs. According to current statistics on the cumulative production effect after conventional fluid extraction in the Santamu Oilfield, the average increase in production per well is 1500-2000 tons. Based on economic assessment, and assuming that the economically recoverable reserves are 20-30% of the well-controlled reserves, the remaining recoverable reserves of the well-controlled fluid extraction well must be greater than 10,000 tons. Only when this material basis is met can single-well fluid extraction be economically viable and the input-output ratio be reasonable.

[0082] Based on reservoir characteristic analysis, the mechanism of fluid extraction and oil production enhancement, and comparison with actual oilfield production data, this embodiment obtains the reservoir standards and interlayer standards for fluid extraction wells. The reservoir standards for fluid extraction wells are as follows: the reservoir is a positive rhythmic reservoir, and the permeability difference between the upper and lower layers of the reservoir is greater than 10; the interlayer standards are as follows: the thickness of the interlayer is greater than 2m, and the main properties of the interlayer are argillaceous or calcareous interlayers.

[0083] The specific principle analysis and standard acquisition process are as follows:

[0084] The reservoir is a positive flow rate reservoir with uneven water washing across its upper and lower sections. Due to the positive flow rate deposition, the vertical physical properties are good at the bottom and poor at the top, with high mobilization at the bottom and low mobilization at the top. This inevitably leads to residual oil retention at the top due to the influence of physical properties. Figure 4 As shown, taking a certain well as an example, the top reservoir lithology of the TⅢ oil group is mainly silt to fine sand, with poor permeability, averaging between 30-40 Md, and slow dripping. The lower reservoir, however, is gravelly coarse sandstone with high permeability, averaging between 200-500 Md, classifying it as a medium-to-high permeability reservoir with high oil saturation and dripping droplet-like permeability. Two tests of this well clearly show that when the upper and lower layers are produced together, the output is high. However, when the top reservoir is tested alone, the oil production decreases significantly. This is because gas accumulates at higher levels, simply increasing gas production. Therefore, the good bottom reservoir is the true main producing layer, while the top, due to inter-layer heterogeneity, has residual oil accumulation. Thus, fluid extraction essentially increases the production pressure differential, utilizing the residual oil and gas in the poorer top reservoir. Therefore, to ensure the effectiveness of fluid extraction, the greater the permeability difference between the upper and lower reservoir layers, the better.

[0085] The interlayers are well-developed and can effectively block bottom water coning. Due to the shielding effect of the interlayers, they provide some protection against bottom water, thus inhibiting water aquifer growth. Figure 5 As shown. Figure 6 and Figure 7 As shown, taking a certain well as an example, a 2m thick calcareous interlayer developed in the perforated section of the well. Due to the development of the interlayer, the effect of fluid extraction was significant, with daily fluid production increasing from 149 tons to 196 tons, daily oil production increasing from 2 tons to 15 tons, and water cut decreasing by 8 percentage points. Currently, the staged oil production is 1449 tons. Therefore, based on the statistics of the effects of fluid extraction wells over the years, the fluid extraction effect is better when the layer thickness is more than 2m, and the fluid extraction effect is excellent when the interlayer is mainly composed of argillaceous or calcareous interlayers with strong sealing properties.

[0086] like Figure 3 As shown, one embodiment provides a well selection device for high water flooding followed by fluid extraction in a single well of a large bottom water reservoir. This device can be used to implement the above-mentioned method for selecting a well for high water flooding followed by fluid extraction in a single well of a large bottom water reservoir. Specifically, the well selection system for high water flooding followed by fluid extraction in a single well of a large bottom water reservoir includes a standard acquisition module, a screening module, and a discrimination module.

[0087] The standard acquisition module is used to acquire the selection criteria for liquid extraction wells and classify the remaining recoverable reserves criteria.

[0088] The screening module is used to initially screen single wells in the target reservoir that meet the standard of remaining recoverable reserves, and to obtain preliminary target wells.

[0089] The discrimination module is used to obtain the reservoir conditions, interlayer conditions and water cut of the preliminary target well, and compare them with the selection criteria for liquid extraction wells. If the selection criteria for liquid extraction wells are met, the preliminary target well can be used for liquid extraction.

[0090] Furthermore, in one embodiment, a well-selection device for high water flooding after fluid extraction in a single well of a large bottom water reservoir is provided, comprising:

[0091] The standard acquisition module is used to predict the maximum fluid extraction and oil production increase ratio and timing of fluid extraction in a single well within a target reservoir using reservoir numerical simulation methods. Based on the maximum fluid extraction and oil production increase ratio and timing, it obtains the water cut standard for the extraction well. Based on reservoir characteristic analysis, the fluid extraction and oil production increase mechanism, and actual oilfield production data, it obtains the reservoir standard and interlayer standard for the extraction well. Based on the proportion of economically recoverable reserves, the cost of fluid extraction, and the production increase effect after fluid extraction, it obtains the standard for remaining recoverable reserves.

[0092] The screening module is used to initially screen single wells in the target reservoir that meet the standard of remaining recoverable reserves, and to obtain preliminary target wells.

[0093] The discrimination module is used to obtain the reservoir conditions, interlayer conditions, and water cut of the preliminary target well, and compare them with the reservoir standards, interlayer standards, and water cut standards of the extraction well, respectively, to comprehensively determine whether the preliminary target well can be used for extraction.

[0094] In the above-mentioned device, the water cut standard for the extraction well is a water cut between 90% and 94%; the reservoir standard for the extraction well is as follows: the reservoir is a positive rhythmic reservoir, and the permeability difference between the upper and lower parts of the reservoir is greater than 10; the interlayer standard is as follows: the thickness of the interlayer is greater than 2m, and the main properties of the interlayer are clay interlayer or calcareous interlayer; the remaining recoverable reserves standard is greater than 10,000 tons.

[0095] like Figure 11 As shown, this embodiment provides an electronic device 10, which is intended to represent various forms of digital computers, such as laptop computers, desktop computers, workstations, personal digital assistants, servers, blade servers, mainframe computers, and other suitable computers. The electronic device can also represent various forms of mobile devices, such as personal digital processors, cellular phones, smartphones, wearable devices (such as helmets, glasses, watches, etc.), and other similar computing devices. The components shown herein, their connections and relationships, and their functions are merely illustrative and are not intended to limit the implementation of the invention described and / or claimed herein.

[0096] like Figure 11 As shown, the electronic device 10 includes at least one processor 11 and a memory, such as a read-only memory (ROM) 12 or a random access memory (RAM) 13, communicatively connected to the at least one processor 11. The memory stores computer programs executable by the at least one processor. The processor 11 can perform various appropriate actions and processes based on the computer program stored in the ROM 12 or loaded from storage unit 18 into the RAM 13. The RAM 13 may also store various programs and data required for the operation of the electronic device 10. The processor 11, ROM 12, and RAM 13 are interconnected via a bus 14. An input / output (I / O) interface 15 is also connected to the bus 14.

[0097] Multiple components in electronic device 10 are connected to I / O interface 15, including: input unit 16, such as keyboard, mouse, etc.; output unit 17, such as various types of displays, speakers, etc.; storage unit 18, such as disk, optical disk, etc.; and communication unit 19, such as network card, modem, wireless transceiver, etc. Communication unit 19 allows electronic device 10 to exchange information / data with other devices through computer networks such as the Internet and / or various telecommunications networks.

[0098] Processor 11 can be a variety of general-purpose and / or special-purpose processing components with processing and computing capabilities. Some examples of processor 11 include, but are not limited to, central processing unit (CPU), graphics processing unit (GPU), various special-purpose artificial intelligence (AI) computing chips, various processors running machine learning model algorithms, digital signal processors (DSPs), and any suitable processor, controller, microcontroller, etc. Processor 11 performs the various methods and processes described above, such as the high-water-flooding post-fluid extraction well selection method for single wells in large bottom-water reservoirs.

[0099] In some embodiments, the method for selecting a single well in a large-bottom-water reservoir after high water flooding and fluid extraction can be implemented as a computer program tangibly contained in a computer-readable storage medium, such as storage unit 18. In some embodiments, part or all of the computer program can be loaded and / or installed on electronic device 10 via ROM 12 and / or communication unit 19. When the computer program is loaded into RAM 13 and executed by processor 11, one or more steps of the method for selecting a single well in a large-bottom-water reservoir after high water flooding and fluid extraction described above can be performed. Alternatively, in other embodiments, processor 11 can be configured to perform the method for selecting a single well in a large-bottom-water reservoir after high water flooding and fluid extraction by any other suitable means (e.g., by means of firmware).

[0100] Various embodiments of the systems and techniques described above herein can be implemented in digital electronic circuit systems, integrated circuit systems, field-programmable gate arrays (FPGAs), application-specific integrated circuits (ASICs), application-specific standard products (ASSPs), systems-on-a-chip (SoCs), payload-programmable logic devices (CPLDs), computer hardware, firmware, software, and / or combinations thereof. These various embodiments may include implementations in one or more computer programs that can be executed and / or interpreted on a programmable system including at least one programmable processor, which may be a dedicated or general-purpose programmable processor, capable of receiving data and instructions from a storage system, at least one input device, and at least one output device, and transmitting data and instructions to the storage system, the at least one input device, and the at least one output device.

[0101] Computer programs used to implement the methods of the present invention may be written in any combination of one or more programming languages. These computer programs may be provided to a processor of a general-purpose computer, a special-purpose computer, or other programmable data processing device, such that when executed by the processor, the computer programs cause the functions / operations specified in the flowcharts and / or block diagrams to be performed. The computer programs may be executed entirely on a machine, partially on a machine, or as a standalone software package, partially on a machine and partially on a remote machine, or entirely on a remote machine or server.

[0102] In the context of this invention, a computer-readable storage medium can be a tangible medium that may contain or store a computer program for use by or in conjunction with an instruction execution system, apparatus, or device. A computer-readable storage medium may include, but is not limited to, electronic, magnetic, optical, electromagnetic, infrared, or semiconductor systems, apparatus, or devices, or any suitable combination thereof. Alternatively, a computer-readable storage medium may be a machine-readable signal medium. More specific examples of machine-readable storage media include electrical connections based on one or more wires, portable computer disks, hard disks, random access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM or flash memory), optical fibers, portable compact disk read-only memory (CD-ROM), optical storage devices, magnetic storage devices, or any suitable combination thereof.

[0103] The above content is only for illustrating the technical concept of the present invention and should not be construed as limiting the scope of protection of the present invention. Any modifications made to the technical solution based on the technical concept proposed in this invention shall fall within the scope of protection of the claims of this invention.

Claims

1. A method for selecting a single well in a large-bottom-water reservoir after high water flooding and fluid extraction, characterized in that, Includes the following steps: Obtain the selection criteria for extraction wells and delineate the remaining recoverable reserves; Preliminary screening of single wells within the target reservoir that meet the standard for remaining recoverable reserves yields preliminary target wells. Obtain information on the reservoir, interlayers, and water cut of the preliminary target well, and compare it with the selection criteria for fluid extraction wells. If the selection criteria for fluid extraction wells are met, the preliminary target well can be used for fluid extraction.

2. The method for selecting a single well in a large-bottom-water reservoir after high water flooding and fluid extraction according to claim 1, characterized in that, The selection criteria for extraction wells include the water cut standard, the reservoir standard, and the interlayer standard.

3. The method for selecting a single well in a large-bottom-water reservoir after high water flooding and fluid extraction according to claim 2, characterized in that, The water cut standard for the extraction well is a water cut between 90% and 94%.

4. The method for selecting a single well in a large-bottom-water reservoir after high water flooding and fluid extraction according to claim 2, characterized in that, The process for obtaining the water cut standard of the extraction well is as follows: The extraction ratio and timing of the maximum extraction and oil production of a single well in the target reservoir are predicted by reservoir numerical simulation. Based on the extraction ratio and timing of the maximum extraction and oil production, the water cut standard of the extraction well is obtained.

5. The method for selecting a single well in a large-bottom-water reservoir after high water flooding and fluid extraction according to claim 2, characterized in that, The reservoir criteria for the fluid extraction wells are as follows: The reservoir is a positive rhythmic reservoir, and the permeability difference between the upper and lower parts of the reservoir is greater than 10.

6. The method for selecting a single well in a large-bottom-water reservoir after high water flooding and fluid extraction according to claim 2, characterized in that, The interlayer standard for the fluid extraction well is as follows: The thickness of the interlayer is greater than 2m, and the main properties of the interlayer are argillaceous interlayer or calcareous interlayer.

7. The method for selecting a single well in a large-bottom-water reservoir after high water flooding and fluid extraction according to claim 1, characterized in that, The standard for remaining recoverable reserves is that the remaining recoverable reserves are greater than 10,000 tons.

8. A well selection device for high water flooding followed by fluid extraction in a single well of a large bottom water reservoir, characterized in that, include: The standard acquisition module is used to acquire the selection criteria for liquid extraction wells and classify the remaining recoverable reserves criteria. The screening module is used to initially screen single wells in the target reservoir that meet the standard of remaining recoverable reserves, and to obtain preliminary target wells. The discrimination module is used to obtain the reservoir conditions, interlayer conditions and water cut of the preliminary target well, and compare them with the selection criteria for liquid extraction wells. If the selection criteria for liquid extraction wells are met, the preliminary target well can be used for liquid extraction.

9. An electronic device, characterized in that, The electronic device includes: at least one processor; and a memory communicatively connected to the at least one processor; wherein... The memory stores a computer program that can be executed by the at least one processor, the computer program being executed by the at least one processor to enable the at least one processor to perform the method for selecting a single well in a large bottom water reservoir after high water flooding, as described in any one of claims 1-7.

10. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores computer instructions that are used to cause a processor to execute the method for selecting a single well in a large bottom water reservoir after high water flooding, as described in any one of claims 1-7.

Images