Method, device, electronic device and medium for determining reasonable production capacity of oil reservoir oil wells

Abstract

The present application discloses a method, device, electronic device and medium for determining the reasonable production capacity of oil wells in an oil reservoir. The method may include: respectively establishing bottom-hole flowing pressure and static pressure equations to predict the bottom-hole flowing pressure and static pressure; calculating the bottom-hole production pressure difference and establishing a relationship curve between the oil well production and the bottom-hole production pressure difference; classifying the flow types for single wells according to the relationship curve; and determining the reasonable production capacity for different types of single wells. By classifying the flow types of oil wells in ultra-deep fault-karst reservoirs, the present invention proposes a method for determining the reasonable production capacity of oil wells for different flow types, which has certain guiding significance for studying the reasonable production capacity of oil wells in similar oil reservoirs.

Description

Technical Field

[0001] The present invention relates to the field of reservoir engineering, and more particularly, to a method, device, electronic device and medium for determining the reasonable production capacity of oil wells in a reservoir. Background Art

[0002] The production capacity refers to the production ability of an oil well, and the production volume refers to the quantity of crude oil produced by the oil well. The production capacity of an oil well is the main basis for oilfield investment and decision-making. The main purpose of studying the reasonable production capacity of an oil well is to maintain a relatively high oil recovery rate and produce at a relatively fast oil production rate, so as to recover the investment as soon as possible. In the process of oilfield development, controlling the choke is the main means of production capacity control. By enlarging the choke and reducing the bottom-hole production pressure difference within a certain pressure difference range, the production capacity of the oil well can be improved, but there is always a maximum production capacity and a reasonable production capacity. Different scholars have different understandings of the reasonable production capacity, and the considered factors and evaluation indicators are not the same. For example: the maximum recovery rate, the best economic benefit, a long stable production time in the short term, and the ability to reach a certain production scale. Some scholars also consider engineering factors, such as: wellbore stability, meeting the pipeline gathering and transportation carrying capacity, etc. The reasonable production capacity is defined as the production capacity of an oil well when the formation liquid supply capacity reaches the best within a period of time. The so-called best means that the formation can continuously supply liquid, supply liquid sufficiently, and the fluid flow maintains a stable state. Continuing to increase or decrease the bottom-hole production pressure difference, that is, changing the production system of the oil well, will break the best state. Whether the production capacity of an oil well is reasonable is mainly considered from the perspective of whether the formation liquid supply capacity is the best. As the reservoir is continuously developed, changes in formation pressure, production boundary, oil-water interface, reservoir parameters, etc. will affect the formation liquid supply capacity, and the reasonable production capacity also changes with time.

[0003] At present, the main methods for determining the reasonable production capacity of oil wells mentioned in the existing literature are as follows:

[0004] ① System well testing. This is currently the most important and most used method for determining the reasonable production capacity of oil wells, also known as production capacity well testing, which is achieved by continuously changing the production volume of the oil well. The production volume of the oil well is controlled by a flow regulator (choke) set at the wellhead. When the flow rate and pressure before and after the choke reach a stable flow state, the relationship between the production volume of the oil well and the bottom-hole flowing pressure under different choke sizes is obtained through testing. Method advantages: It can take into account the reservoir development situation and the actual fluid flow capacity, and is applicable to various types of reservoirs. Especially for strongly heterogeneous reservoirs, unconventional reservoirs, etc., in the absence of a mature production capacity formula, by testing the actual liquid supply capacity of the reservoir, it can better understand the actual production situation of the oil well, and thus determine the reasonable production capacity of the oil well. It has a wide application range and strong popularization ability; Method disadvantages: System well testing takes a long time, requires installing chokes of different sizes, and changing the choke size generally requires about 7 days of stabilization.

[0005] ②Water cone critical production method. Take 1 / 2 - 1 / 3 of the water cone critical production as the reasonable production capacity of the oil well. This method determines the relationship between the reasonable production pressure difference and the oil well production based on reservoir engineering calculations, and is mainly used for calculating the production capacity of oil wells in bottom water reservoirs. The method is simple and practical, but the accuracy needs to be improved.

[0006] ③Analogy method. Summarize the structural, fracture, seismic reflection characteristics and production characteristics of adjacent wells, and based on a large amount of statistical analysis of production data, determine the reasonable production capacity of the oil well by analogy with adjacent wells. This method is widely used in oilfield sites, simple and easy to operate. Since it is an empirical method, its reliability and accuracy need to be further demonstrated.

[0007] ④Reservoir numerical simulation method. Mainly consider the optimization indicators and factors mentioned above, and usually judge based on the maximum recovery rate. This method is based on a full understanding of the reservoir geology in the early stage. After geological modeling, history matching, reservoir numerical simulation and related calculations, it takes a certain amount of time and effort, which is not conducive to popularization.

[0008] ⑤Other methods. Some scholars also use the nodal analysis method to determine the reasonable production capacity of oil wells. However, due to the unknown fluid flow law in the wellbore, the relationship between the bottom hole flowing pressure and the production is not clear, and the calculation of intermediate parameters is relatively complex, so it is difficult to apply.

[0009] In general, the most commonly used method to determine the reasonable production capacity of oil wells is the systematic well testing. This method can fully consider the actual liquid supply capacity of the reservoir and the actual production situation of the oil well. Other methods are generally empirical methods (such as the water cone critical production method, analogy method) or require a long time, a large amount of effort or have great uncertainty (such as the reservoir numerical simulation method). However, due to the strong heterogeneity characteristics of ultra-deep fault dissolution reservoirs, such as cross-layer properties and good vertical connectivity, there are significant differences in their fluid flow characteristics and pressure propagation laws compared with conventional clastic rock reservoirs, resulting in the following problems when using the systematic well testing method to determine the reasonable production capacity of oil wells:

[0010] First, multiple flow types complicate the calculation of oil well productivity. In conventional clastic reservoirs, planar seepage is dominant, and the seepage law conforms to Darcy's law. The oil well output has a linear relationship with the bottom hole flowing pressure. Based on this linear relationship, the productivity index of the oil well can be determined. Then, according to the formula q = JΔp, the production rate of the oil well can be allocated, and only by optimizing the reasonable production pressure difference of the oil well can the reasonable productivity of the oil well be determined. Therefore, it is very easy to determine the productivity index and the reasonable productivity of the oil well based on system well testing. However, for ultra-deep fault-karst reservoirs, due to the significantly higher longitudinal permeability than planar permeability in the breccia zone (core), and the overall permeability of the fracture zone (wing) being smaller than that of the breccia zone (core), fluid flow is mainly longitudinal and supplemented by transverse flow; the longitudinal flow range is large, and the fluid starts to flow towards the bottom hole from several hundred meters below the bottom hole; and current research believes that there are at least several types of flow in the reservoir of the fault-karst reservoir, such as linear flow, low-speed non-linear flow, and high-speed non-linear flow. The flow law is very complex and does not conform to Darcy's law, that is, the productivity index is no longer a fixed value, and the production rate of the oil well cannot be allocated according to the formula q = JΔp;

[0011] Second, the differential pressure propagation law leads to the need for improvement in the processing and interpretation methods of system well testing. In conventional clastic reservoirs, the initial static pressure is related to the burial depth of the reservoir. Since the location of the production layer is generally fixed and the initial static pressure remains unchanged, when the pressure wave propagates to the closed boundary, the boundary pressure begins to decrease. Therefore, it is very easy to determine the production pressure difference of the oil well based on system well testing, and thus the reasonable productivity of the oil well can be optimized. However, for ultra-deep fault-karst reservoirs, first, the production layer is not fixed, and the initial static pressure is not a fixed value but depends on the propagation range of the pressure wave; second, the longitudinal permeability in the core of the fault-karst reservoir is large, and the pressure wave propagates mainly longitudinally and supplemented by transverse flow. After the pressure wave reaches the wing, it continues to propagate downward until it encounters a closed formation longitudinally, that is, there are obvious differences in the pressure propagation law between ultra-deep fault-karst reservoirs and conventional clastic reservoirs. Therefore, there is currently no theoretical formula or mature method to refer to in calculating the production pressure difference of oil wells in fault-karst reservoirs, and only field measurements can be relied on;

[0012] Finally, due to the deep burial of the oilfield, the vertical depth of the completed oil wells exceeds 7000m, belonging to ultra-deep wells, and currently the pressure gauges for system well testing cannot be lowered to the bottom hole.

[0013] Therefore, it is necessary to develop a method, device, electronic equipment and medium for determining the reasonable productivity of oil wells in ultra-deep fault-karst reservoirs to provide certain theoretical support for determining the reasonable productivity of oil wells in ultra-deep fault-karst reservoirs.

[0014] The information disclosed in the background art part of the present invention is only intended to deepen the understanding of the general background art of the present invention, and should not be regarded as an admission or any form of implication that this information constitutes the prior art known to those skilled in the art. Summary of the Invention

[0015] The present invention provides a method, device, electronic device and medium for determining the reasonable production capacity of oil wells in a reservoir, which can classify the flow types of oil wells in a super-deep fault solution reservoir, and propose a method for determining the reasonable production capacity of oil wells for different flow types, having certain guiding significance for studying the reasonable production capacity of oil wells in similar reservoirs.

[0016] In a first aspect, an embodiment of the present disclosure provides a method for determining the reasonable production capacity of oil wells in a reservoir, including:

[0017] Establish bottom-hole flowing pressure and static pressure equations respectively to predict the bottom-hole flowing pressure and static pressure;

[0018] Calculate the bottom-hole production pressure difference and establish a relationship curve between the oil well output and the bottom-hole production pressure difference;

[0019] Classify the flow types for a single well according to the relationship curve;

[0020] Determine the reasonable production capacity for different types of single wells.

[0021] Preferably, the bottom-hole production pressure difference is the difference between the bottom-hole static pressure and the bottom-hole flowing pressure.

[0022] Preferably, classify the flow types for a single well according to the shape characteristics of the relationship curve.

[0023] Preferably, the flow types include: linear flow, low-speed non-linear flow, high-speed non-linear flow, exponential growth type, and transitional type.

[0024] Preferably, determining the reasonable production capacity for different types of single wells includes:

[0025] Determine the relationship curve between the single well type and the single well;

[0026] Determine the reasonable production capacity according to the single well type and the corresponding relationship curve.

[0027] As a specific implementation manner of the embodiment of the present disclosure,

[0028] In a second aspect, an embodiment of the present disclosure further provides a device for determining the reasonable production capacity of oil wells in a reservoir, including:

[0029] A prediction module that respectively establishes bottom-hole flowing pressure and static pressure equations to predict the bottom-hole flowing pressure and static pressure;

[0030] A calculation module that calculates the bottom-hole production pressure difference and establishes a relationship curve between the oil well output and the bottom-hole production pressure difference;

[0031] A classification module that classifies the flow types for a single well according to the relationship curve;

[0032] A reasonable production capacity determination module that determines the reasonable production capacity for different types of single wells.

[0033] Preferably, the bottom-hole production pressure differential is the difference between the bottom-hole static pressure and the bottom-hole flowing pressure.

[0034] Preferably, according to the shape characteristics of the relationship curve, the flow type of a single well is classified.

[0035] Preferably, the flow types include: linear flow, low-speed non-linear flow, high-speed non-linear flow, exponential growth type, and transitional type.

[0036] Preferably, determining the reasonable production capacity for different types of single wells includes:

[0037] Determining the relationship curve between the single well type and the single well;

[0038] Determining the reasonable production capacity according to the single well type and the corresponding relationship curve.

[0039] In a third aspect, an embodiment of the present disclosure further provides an electronic device, which includes:

[0040] A memory storing executable instructions;

[0041] A processor that runs the executable instructions in the memory to implement the method for determining the reasonable production capacity of oil reservoir wells.

[0042] In a fourth aspect, an embodiment of the present disclosure further provides a computer-readable storage medium, which stores a computer program, and when the computer program is executed by a processor, the method for determining the reasonable production capacity of oil reservoir wells is implemented.

[0043] The beneficial effects are as follows: The flow type essentially reflects the actual liquid supply capacity of the reservoir and the actual production situation of the oil well. Considering the flow type of the oil well when determining the reasonable production capacity of the oil well, on the one hand, the obtained reasonable production capacity result conforms to the actual situation of the reservoir and the oil well, which is more persuasive. On the other hand, classifying and categorizing the flow types of oil wells helps to find the common flow characteristics of oil wells in the same type of oil reservoir, laying a foundation for quickly analyzing the reasonable production capacity of other oil wells. Compared with the traditional water coning critical production method and analogy method, this method is more persuasive and reliable; compared with the oil reservoir numerical simulation method, this method requires fewer parameters for calculation. Therefore, it is more convenient and fast to use.

[0044] The methods and devices of the present invention have other characteristics and advantages, which will be obvious from the accompanying drawings incorporated herein and the subsequent detailed description, or will be detailed in the accompanying drawings incorporated herein and the subsequent detailed description, and these accompanying drawings and detailed description are used together to explain the specific principles of the present invention. Description of the Drawings

[0045] The above and other objects, features and advantages of the present invention will become more apparent through a more detailed description of exemplary embodiments of the present invention in conjunction with the accompanying drawings, wherein like reference numerals generally represent like components throughout the exemplary embodiments of the present invention.

[0046] Figure 1 A flow chart showing the steps of a method for determining a reasonable productivity of an oil well in an oil reservoir according to an embodiment of the present invention.

[0047] Figure 2 A schematic diagram showing the relationship between the oil production of Well A in Oil Field Z and the bottom hole production pressure difference according to an embodiment of the present invention.

[0048] Figure 3 A schematic diagram showing a linear flow curve according to an embodiment of the present invention is shown.

[0049] Figure 4a , Figure 4b , Figure 4c Schematic diagrams of low-speed nonlinear flow curves according to an embodiment of the present invention are respectively shown.

[0050] Figure 5a , Figure 5b , Figure 5c Schematic diagrams of high-speed nonlinear flow curves according to an embodiment of the present invention are respectively shown.

[0051] Figure 6 A schematic diagram of an exponential growth curve according to an embodiment of the present invention is shown.

[0052] Figure 7a and Figure 7b Schematic diagrams of transition curves according to an embodiment of the present invention are respectively shown.

[0053] Figure 8 A block diagram of a device for determining a reasonable production capacity of an oil reservoir and an oil well according to an embodiment of the present invention is shown.

[0054] Description of reference numerals:

[0055] 201. Forecasting module; 202. Calculation module; 203. Classification module; 204. Reasonable capacity determination module. DETAILED DESCRIPTION

[0056] The preferred embodiments of the present invention will be described in more detail below. Although the preferred embodiments of the present invention are described below, it should be understood that the present invention can be implemented in various forms and should not be limited to the embodiments set forth herein.

[0057] In recent years, significant breakthroughs have been achieved in oil and gas exploration in the Tarim Basin, and a carbonate rock fault-karst reservoir with ultra-deep burial (the burial depth of the target layer is greater than 6000 m), namely the Z ultra-deep reservoir, has been discovered. After multiple phases of tectonic compression and other effects on the Middle-Lower Ordovician carbonate rocks in the Z area, fracture zones of a certain scale have developed along deep fault zones. The development and formation of fracture-cavity reservoirs are affected by fault fractures and dissolution. Oil and gas mainly migrate vertically along deep source faults and are injected to form reservoirs, showing obvious cross-layer characteristics in the section and good vertical connectivity. The discovery of the Z ultra-deep fault-karst reservoir has kicked off the rolling exploration and development of the Z oilfield. With the continuous production of new wells, due to the particularity and complexity of the reservoir, a key technical problem currently faced in the development of the Z oilfield is how to determine the reasonable productivity of oil wells in such reservoirs.

[0058] Studying the reasonable productivity of oil wells in the Z ultra-deep fault-karst reservoir is related to the formulation of a reasonable production system in the current Z oilfield on the one hand, and on the other hand, it is also related to whether the Z oilfield can be efficiently developed and stably produced in the long term. At the same time, it also has reference significance for studying the method of determining the reasonable productivity of oil wells in similar reservoirs. Therefore, for ultra-deep fault-karst reservoirs like Z, studying the reasonable productivity of oil wells has very important practical and theoretical guiding significance.

[0059] The present invention provides a method for determining the reasonable productivity of oil wells in a reservoir, including:

[0060] Establish bottom-hole flowing pressure and static pressure equations respectively to predict the bottom-hole flowing pressure and static pressure.

[0061] Specifically, for the pressure measurement results at different depths under each production system, several sets of flowing pressure and static pressure test data close to the bottom hole are reasonably selected, and the bottom-hole flowing pressure and static pressure equations are respectively regressed, and the bottom-hole flowing pressure and static pressure are predicted based on these equations.

[0062] Calculate the bottom-hole production pressure difference and establish a relationship curve between the oil well production and the bottom-hole production pressure difference; in one example, the bottom-hole production pressure difference is the difference between the bottom-hole static pressure and the bottom-hole flowing pressure.

[0063] Specifically, considering that the reservoir of the ultra-deep fault-karst reservoir is unclear in terms of reservoir and boundary, the static pressure is not "static", and the initial formation pressure cannot be determined, it is difficult to accurately obtain the oil well production pressure difference and establish the relationship between the oil well production pressure difference and the production. To simplify the calculation and facilitate the use of on-site personnel, the bottom-hole production pressure difference, that is, "bottom-hole initial static pressure - bottom-hole flowing pressure", is used to characterize the oil well production pressure difference, and the relationship between the production and the bottom-hole production pressure difference is established based on the production data obtained from systematic well testing, laying a foundation for analyzing the flow type of oil wells in the ultra-deep fault-karst reservoir later.

[0064] According to the relationship curve, classify the flow type for a single well; in one example, classify the flow type for a single well according to the shape characteristics of the relationship curve. In one example, the flow types include: linear flow, low-speed non-linear flow, high-speed non-linear flow, exponential growth type, and transitional type.

[0065] Specifically, for several wells in a development unit or block, based on the characteristics of the relationship curve between the oil production per well and the bottom-hole production pressure differential, the flow types of oil wells can be classified. Similarly, for a new well, by plotting the relationship curve between the well production and the bottom-hole production pressure differential, its flow type can also be classified. Among them, the typical flow types of oil wells in conventional clastic reservoirs are: Darcy flow, high-speed non-Darcy flow, low-speed non-Darcy flow, etc. For ultra-deep fault-karst reservoirs such as Z, due to the development of deep major faults and longitudinal high-angle fractures, the fluid has strong longitudinal flow ability, and the flow law does not conform to Darcy's law. It is necessary to classify the flow types of oil wells in ultra-deep fault-karst reservoirs based on the characteristics of the relationship between production and bottom-hole production pressure differential. The flow types for a single well include: linear flow, low-speed non-linear flow, high-speed non-linear flow, exponential growth type, and transitional type.

[0066] Determine the reasonable production capacity for different types of single wells. In one example, determining the reasonable production capacity for different types of single wells includes: determining the relationship curve between the single well type and the single well; and determining the reasonable production capacity according to the single well type and the corresponding relationship curve.

[0067] Specifically, different oil well flow types reflect reservoir differences and different production characteristics of oil wells. Combining other indicators (such as the oil production index, etc.) or considering other factors (such as production establishment, stable production, pipeline gathering and transportation carrying capacity, etc.) can determine the reasonable production capacity of oil wells in ultra-deep fault-karst reservoirs. However, for different oil well flow types, there are differences in the indicators or factors considered when determining the reasonable production capacity of oil wells. For example: High-speed non-Darcy or high-speed non-linear flow reflects that the flow resistance suddenly increases when the fluid flows at high speed, the reservoir liquid supply capacity decreases, and it cannot continuously supply liquid sufficiently. The fluid flow is not an optimal state. Continuing to increase the bottom-hole production pressure differential, the well production gradually deviates from the optimal state (Darcy flow or linear flow stage). At this time, the reasonable production capacity should be set before the inflection point of non-Darcy flow or non-linear flow. The methods for determining the reasonable production capacity of oil wells under other flow types refer to the following embodiments.

[0068] Based on the differences in fluid flow types between ultra-deep fault-karst reservoirs and clastic reservoirs, this method fully interprets the system well test data, improves from aspects of flowing pressure, static pressure prediction, and bottom-hole production pressure differential characterization on the basis of the traditional method for determining reasonable production capacity by system well test, classifies the flow types of oil wells in ultra-deep fault-karst reservoirs, and proposes methods for determining the reasonable production capacity of oil wells for different flow types, which has certain guiding significance for studying the reasonable production capacity of oil wells in similar reservoirs.

[0069] The present invention also provides an apparatus for determining the reasonable production capacity of oil reservoir oil wells, including:

[0070] A prediction module that respectively establishes equations for bottom-hole flowing pressure and static pressure to predict the bottom-hole flowing pressure and static pressure.

[0071] Specifically, for the pressure measurement results at different depths under each production regime, several sets of flowing pressure and static pressure test data near the bottom hole are reasonably selected, and the bottom hole flowing pressure and static pressure equations are respectively regressed, and the bottom hole flowing pressure and static pressure are predicted based on these equations.

[0072] A calculation module calculates the bottom hole production pressure differential and establishes a relationship curve between the oil well production rate and the bottom hole production pressure differential; in one example, the bottom hole production pressure differential is the difference between the bottom hole static pressure and the bottom hole flowing pressure.

[0073] Specifically, considering that in ultra-deep fault-karst reservoirs, the reservoir is unclear, the boundary is unclear, the static pressure is not "static", and the initial formation pressure cannot be determined, it is difficult to accurately obtain the oil well production pressure differential and establish the relationship between the oil well production pressure differential and the production rate. To simplify the calculation and facilitate the use by on-site personnel, the bottom hole production pressure differential, i.e., "bottom hole initial static pressure - bottom hole flowing pressure", is used to characterize the oil well production pressure differential, and the relationship between the production rate and the bottom hole production pressure differential is established based on the production rate data obtained from systematic well testing, laying a foundation for the subsequent analysis of the flow types of oil wells in ultra-deep fault-karst reservoirs.

[0074] A classification module classifies the flow types for a single well according to the relationship curve; in one example, the flow types of a single well are classified according to the shape characteristics of the relationship curve. In one example, the flow types include: linear flow, low-speed non-linear flow, high-speed non-linear flow, exponential growth type, and transitional type.

[0075] Specifically, for several wells in a development unit or block, the flow types of oil wells can be divided based on the characteristics of the relationship curve between the oil production rate per well and the bottom hole production pressure differential; similarly, for a new well, the flow type can also be classified by plotting the relationship curve between the oil well production rate and the bottom hole production pressure differential. Among them, the typical flow types of oil wells in conventional clastic rock reservoirs are: Darcy flow, high-speed non-Darcy, low-speed non-Darcy, etc. For ultra-deep fault-karst reservoirs such as Z, due to the development of deep and large faults and longitudinal high-angle fractures, the longitudinal fluid flow ability is strong, and the flow law does not conform to Darcy's law. The flow types of oil wells in ultra-deep fault-karst reservoirs need to be divided based on the characteristics of the relationship between the production rate and the bottom hole production pressure differential. The flow types for a single well include: linear flow, low-speed non-linear flow, high-speed non-linear flow, exponential growth type, and transitional type.

[0076] A reasonable production capacity determination module determines the reasonable production capacity for different types of single wells. In one example, determining the reasonable production capacity for different types of single wells includes: determining the relationship curve between the single well type and the single well; according to the single well type and the corresponding relationship curve, determining the reasonable production capacity.

[0077] Specifically, different oil well flow types reflect reservoir differences and different production characteristics of oil wells. Combining other indicators (such as oil production index, etc.) or considering other factors (such as well completion, stable production, pipeline gathering and transportation capacity, etc.) can determine the reasonable production capacity of oil wells in ultra-deep fault dissolution reservoirs. However, for different oil well flow types, there are differences in the indicators used or factors considered when determining the reasonable production capacity of oil wells. For example, high-speed non-Darcy or high-speed non-linear flow reflects that the flow resistance of the fluid suddenly increases during high-speed flow, the reservoir liquid supply capacity decreases, and it cannot continuously supply liquid sufficiently. The fluid flow is not an optimal state. Continuing to increase the bottom-hole production pressure difference, the oil well production gradually deviates from the optimal state (Darcy flow or linear flow stage). At this time, the reasonable production capacity should be set before the inflection point of non-Darcy flow or non-linear flow. The method for determining the reasonable production capacity of oil wells under other flow types refers to the following embodiments.

[0078] The present invention also provides an electronic device, which includes: a memory storing executable instructions; a processor that runs the executable instructions in the memory to implement the above-mentioned method for determining the reasonable production capacity of oil reservoir wells.

[0079] The present invention also provides a computer-readable storage medium, which stores a computer program that implements the above-mentioned method for determining the reasonable production capacity of oil reservoir wells when executed by a processor.

[0080] To facilitate understanding of the solution and its effects of the embodiments of the present invention, the following gives four specific application examples. Those skilled in the art should understand that this example is only for facilitating the understanding of the present invention, and any specific details are not intended to limit the present invention in any way.

[0081] Example 1

[0082] Figure 1 A flowchart showing the steps of the method for determining the reasonable production capacity of oil reservoir wells according to the present invention is shown.

[0083] As Figure 1 shown, the method for determining the reasonable production capacity of oil reservoir wells includes: Step 101, respectively establish bottom-hole flowing pressure and static pressure equations to predict the bottom-hole flowing pressure and static pressure; Step 102, calculate the bottom-hole production pressure difference and establish a relationship curve between the oil well production and the bottom-hole production pressure difference; Step 103, according to the relationship curve, classify the flow types for single wells; Step 104, determine the reasonable production capacity for different types of single wells.

[0084] The present invention takes a super-deep fault solution reservoir in Oilfield Z as an example for case application. For each oil well, the systematic well test data is comprehensively dissected and analyzed to predict the bottom-hole flowing pressure under different production regimes (nozzle sizes); similarly, based on the static pressure prediction results, the bottom-hole production pressure difference under different nozzle sizes in the systematic well test is calculated. Table 1 shows the prediction results of the bottom-hole flowing pressure and the bottom-hole production pressure difference of Well A in Oilfield Z under different nozzle sizes.

[0085] Table 1

[0086]

[0087] Figure 2 The schematic diagram shows the relationship between the oil production of Well A in Oilfield Z and the bottom-hole production pressure difference according to an embodiment of the present invention.

[0088] Combined with the oil well production test data of the systematic well test, the relationship between the oil well production and the bottom-hole production pressure difference is established, as Figure 2 shown.

[0089] According to the same method, the relationship between the oil production of other oil wells and the bottom-hole production pressure difference can be established, and the flow types of oil wells can be preliminarily divided according to the curve characteristics. For each flow type, the oil well can be allocated production, and the reasonable production capacity of the oil well can be comprehensively determined in combination with other indicators and factors. Specifically as follows:

[0090] Figure 3 The schematic diagram shows the linear flow curve according to an embodiment of the present invention.

[0091] (1) Linear flow, as Figure 3 shown. This flow type indicates that within a certain pressure difference range, the oil production is linearly related to the bottom-hole production pressure difference. Increasing the bottom-hole production pressure difference, the oil production almost increases proportionally, indicating that the flow resistance remains unchanged and the formation liquid supply capacity is less affected by the production regime change. The oil well production can be allocated according to this linear relationship, but to determine the reasonable production capacity of the oil well, other indicators or factors need to be considered. Here, the difference in the productivity index is compared after differentiation, and combined with the change rate of the bottom-hole flowing pressure under different nozzle sizes, the reasonable production capacity of this well is finally determined to be 134 m 3 / d.

[0092] Figure 4a 、 Figure 4b 、 Figure 4c The schematic diagrams show the low-speed non-linear flow curves according to an embodiment of the present invention.

[0093] (2) Low-speed non-linear flow, as Figure 4a 、 Figure 4b 、 Figure 4cAs shown. When the bottom-hole production pressure difference is large, the oil production rate is linearly related to the bottom-hole production pressure difference. When the bottom-hole production pressure difference is small, there is an inflection point in the curve, that is, the fluid conforms to linear flow under high-speed flow conditions and does not conform to linear flow under low-speed flow conditions. This shows that increasing the bottom-hole production pressure difference, although the flow resistance increases after the inflection point, but as the bottom-hole production pressure difference continues to increase, the flow state is not significantly affected, the formation liquid supply capacity difference is small, and the formation can be ensured to supply sufficient liquid. The reasonable bottom-hole production pressure difference should be set after the inflection point, and the reasonable production capacity of the oil well is determined accordingly. Finally, it is determined that Figure 4a 、 Figure 4b 、 Figure 4c The reasonable production capacities of the corresponding wells are respectively: 107 - 165 m 3 / d (corresponding to 4 mm and 5 mm nozzles), 242 - 274 m 3 / d (corresponding to 5.5 mm and 6 mm nozzles) and 108 - 141 m 3 / d (corresponding to 4 mm and 5 mm nozzles).

[0094] Figure 5a 、 Figure 5b 、 Figure 5c respectively show schematic diagrams of the high-speed non-linear flow curve according to an embodiment of the present invention.

[0095] (3) High-speed non-linear flow, such as Figure 5a 、 Figure 5b 、 Figure 5c As shown. When the bottom-hole production pressure difference is small, the oil production rate is linearly related to the bottom-hole production pressure difference. Continuing to increase the bottom-hole production pressure difference, an obvious inflection point appears in the curve, that is, the fluid does not conform to linear flow under high-speed flow conditions and conforms to linear flow under low-speed flow conditions. This shows that increasing the bottom-hole production pressure difference, the flow resistance increases significantly after the inflection point, the flow state is significantly affected, the formation liquid supply capacity decreases, and the formation cannot supply sufficient liquid for a long time. The reasonable bottom-hole production pressure difference should be set before the inflection point, and the reasonable production capacity of the oil well is determined accordingly. Finally, it is determined that Figure 5a 、 Figure 5b 、 Figure 5c The reasonable production capacities of the corresponding wells are respectively: 69 - 86 m 3 / d (corresponding to 3.5 mm and 4 mm nozzles), 85 - 126 m 3 / d (corresponding to 4 mm and 5 mm nozzles) and 108 - 134 m 3 / d (corresponding to 3.5 mm and 4 mm nozzles).

[0096] Figure 6 shows a schematic diagram of the exponential growth curve according to an embodiment of the present invention.

[0097] (4) Exponential growth type, such as Figure 6As shown. This type of flow indicates that within a certain pressure difference range, as the bottom-hole production pressure difference increases, the oil production rate increases exponentially. The choke can be enlarged for production. The main reasons are that the reservoir body is very large, has strong energy, and sufficient liquid supply. In this case, when determining the reasonable production capacity, it is advisable to consider whether the wellbore stability and the gathering and transportation bearing capacity of the surface pipeline meet the requirements. It is recommended that this well continue to expand the choke and conduct production and pressure tests to determine the reasonable production capacity later.

[0098] Figure 7a and Figure 7b respectively show schematic diagrams of a transition curve according to an embodiment of the present invention.

[0099] (5) Transitional type, such as Figure 7a 、 Figure 7b shown. As the bottom-hole production pressure difference increases, the production rate rises in a stepwise manner. Before and after the step, the oil production rate increases rapidly with the bottom-hole production pressure difference. The oil production of the oil well can be allocated by determining the bottom-hole production pressure difference before and after the step. The reasonable production capacity in the early stage can take the production capacity corresponding to the step. Finally, it is determined that Figure 7a 、 Figure 7b the reasonable production capacities of the corresponding wells are: 112 m 3 / d and 113 m 3 / d.

[0100] The summary of the reasonable production capacity results of the oil wells in a certain ultra-deep fault-karst reservoir in Z Oilfield is shown in Table 5.

[0101] Table 5

[0102]

[0103] Example 2

[0104] Figure 8 shows a block diagram of a device for determining the reasonable production capacity of an oil reservoir oil well according to an embodiment of the present invention.

[0105] As Figure 8 shown, the device for determining the reasonable production capacity of an oil reservoir oil well includes:

[0106] A prediction module 201 that respectively establishes bottom-hole flowing pressure and static pressure equations to predict the bottom-hole flowing pressure and static pressure;

[0107] A calculation module 202 that calculates the bottom-hole production pressure difference and establishes a relationship curve between the oil well production rate and the bottom-hole production pressure difference;

[0108] A classification module 203 that classifies the flow types for single wells according to the relationship curve;

[0109] A reasonable production capacity determination module 204 that determines the reasonable production capacity for different types of single wells.

[0110] As an alternative, the bottom-hole production pressure differential is the difference between the bottom-hole static pressure and the bottom-hole flowing pressure.

[0111] As an alternative, according to the shape characteristics of the relationship curve, the flow type of a single well is classified.

[0112] As an alternative, the flow types include: linear flow, low-speed non-linear flow, high-speed non-linear flow, exponential growth type, and transitional type.

[0113] As an alternative, the determination of reasonable production capacity for different types of single wells includes:

[0114] Determine the relationship curve between the single-well type and the single well;

[0115] According to the single-well type and the corresponding relationship curve, determine the reasonable production capacity.

[0116] Example 3

[0117] The present disclosure provides an electronic device, which includes: a memory storing executable instructions; a processor that runs the executable instructions in the memory to implement the above-mentioned method for determining the reasonable production capacity of oil reservoir oil wells.

[0118] The electronic device according to an embodiment of the present disclosure includes a memory and a processor.

[0119] The memory is used to store non-temporary computer-readable instructions. Specifically, the memory may include one or more computer program products, and the computer program products may include various forms of computer-readable storage media, such as volatile memory and / or non-volatile memory. The volatile memory may include, for example, random access memory (RAM) and / or cache memory, etc. The non-volatile memory may include, for example, read-only memory (ROM), hard disk, flash memory, etc.

[0120] The processor may be a central processing unit (CPU) or other forms of processing units with data processing capabilities and / or instruction execution capabilities, and may control other components in the electronic device to perform desired functions. In an embodiment of the present disclosure, the processor is used to run the computer-readable instructions stored in the memory.

[0121] Those skilled in the art should understand that, in order to solve the technical problem of how to obtain good user experience effects, this embodiment may also include well-known structures such as communication buses and interfaces, and these well-known structures should also be included in the protection scope of the present disclosure.

[0122] For the detailed description of this embodiment, reference may be made to the corresponding descriptions in the foregoing embodiments, and details will not be repeated here.

[0123] Example 4

[0124] An embodiment of the present disclosure provides a computer-readable storage medium storing a computer program, which when executed by a processor, implements the method for determining a reasonable production capacity of an oil reservoir well described above.

[0125] The computer-readable storage medium according to an embodiment of the present disclosure stores non-transitory computer-readable instructions. When the non-transitory computer-readable instructions are run by a processor, all or part of the steps of the methods of the various embodiments of the present disclosure described above are executed.

[0126] The above computer-readable storage medium includes, but is not limited to: optical storage media (such as CD-ROMs and DVDs), magneto-optical storage media (such as MOs), magnetic storage media (such as magnetic tapes or external hard drives), media with built-in rewritable non-volatile memories (such as memory cards), and media with built-in ROMs (such as ROM cartridges).

[0127] Those skilled in the art should understand that the purpose of the above description of the embodiments of the present invention is only to exemplarily illustrate the beneficial effects of the embodiments of the present invention, and is not intended to limit the embodiments of the present invention to any example given.

[0128] The various embodiments of the present invention have been described above. The above description is exemplary and not exhaustive, and is also not limited to the disclosed embodiments. Many modifications and variations are obvious to those of ordinary skill in the art without departing from the scope and spirit of the described embodiments.

Claims

1. A method for determining the reasonable production capacity of oil wells in an oil reservoir, characterized in that, Including: Respectively establish the bottom-hole flowing pressure and static pressure equations to predict the bottom-hole flowing pressure and static pressure; Calculate the bottom-hole production pressure differential, and establish a relationship curve between the oil well production rate and the bottom-hole production pressure differential; use the bottom-hole production pressure differential, i.e., "bottom-hole initial static pressure - bottom-hole flowing pressure", to characterize the oil well production pressure differential; According to the relationship curve, classify the flow types for single wells, and divide the flow types of oil wells in ultra-deep fault-karst reservoirs based on the relationship characteristics between production rate and bottom-hole production pressure differential; Determine the reasonable production capacity for different types of single wells; Wherein, the bottom-hole production pressure differential is the difference between the bottom-hole static pressure and the bottom-hole flowing pressure; Wherein, according to the shape characteristics of the relationship curve, classify the flow types for single wells; Wherein, the flow types include: linear flow, low-speed non-linear flow, high-speed non-linear flow, exponential growth type, and transitional type; Wherein, the linear relationship of linear flow is used to allocate production for oil wells, compare the differences in productivity indices after differentiation, and combine the change rate of bottom-hole flowing pressure under different nozzle sizes to determine the reasonable production capacity of oil wells; Low-speed non-linear flow, that is, the fluid conforms to linear flow in the high-speed flow state and does not conform to linear flow in the low-speed flow state. Increasing the bottom-hole production pressure differential, the flow resistance increases after the inflection point. As the bottom-hole production pressure differential continues to increase, the flow state is not affected, and the formation liquid supply capacity difference is small, which can ensure sufficient formation liquid supply. The reasonable bottom-hole production pressure differential is determined after the inflection point, and the reasonable production capacity of the oil well is determined accordingly; High-speed non-linear flow, that is, the fluid does not conform to linear flow in the high-speed flow state and conforms to linear flow in the low-speed flow state. Increasing the bottom-hole production pressure differential, the flow resistance increases after the inflection point, and the flow state is affected, and the formation liquid supply capacity decreases, and the formation liquid supply cannot be maintained sufficient for a long time. The reasonable bottom-hole production pressure differential is determined before the inflection point, and the reasonable production capacity of the oil well is determined accordingly; Exponential growth type, within a certain pressure differential range, as the bottom-hole production pressure differential increases, the oil production rate increases exponentially. It is possible to enlarge the nozzle production. When determining the reasonable production capacity, it is advisable to consider whether the wellbore stability and the ground pipeline gathering and transportation bearing capacity meet the requirements, expand the nozzle to carry out production and pressure testing research, and then determine the reasonable production capacity; Transitional type, as the bottom-hole production pressure differential increases, the production rate rises in a stepwise manner, and before and after the step, the oil production rate increases rapidly with the bottom-hole production pressure differential. Allocate production for the oil well by determining the bottom-hole production pressure differential before and after the step, and the reasonable production capacity is the production capacity corresponding to the step; 2. The method for determining the reasonable production capacity of oil wells in an oil reservoir according to claim 1, wherein, Determining the reasonable production capacity for different types of single wells includes: Determine the relationship curve between the single well type and the single well; According to the single well type and the corresponding relationship curve, determine the reasonable production capacity.

3. A device for determining the reasonable production capacity of oil wells in an oil reservoir, characterized in that, Including: A prediction module that respectively establishes the bottom-hole flowing pressure and static pressure equations to predict the bottom-hole flowing pressure and static pressure; A calculation module that calculates the bottom-hole production pressure differential and establishes a relationship curve between the oil well production rate and the bottom-hole production pressure differential; uses the bottom-hole production pressure differential, i.e., "bottom-hole initial static pressure - bottom-hole flowing pressure", to characterize the oil well production pressure differential; A classification module that classifies the flow types for single wells according to the relationship curve, and divides the flow types of oil wells in ultra-deep fault-karst reservoirs based on the relationship characteristics between production rate and bottom-hole production pressure differential; A reasonable production capacity determination module that determines the reasonable production capacity for different types of single wells; Wherein, the bottom-hole production pressure differential is the difference between the bottom-hole static pressure and the bottom-hole flowing pressure; Wherein, according to the shape characteristics of the relationship curve, the flow type of a single well is classified; Wherein, the flow types include: linear flow, low-speed non-linear flow, high-speed non-linear flow, exponential growth type, and transition type; Wherein, the linear relationship of the linear flow is used to allocate production for the oil well, compare the difference in the productivity index after derivation, and combine the change rate of the bottom-hole flowing pressure under different choke sizes to determine the reasonable productivity of the oil well; For low-speed non-linear flow, that is, the fluid conforms to linear flow under high-speed flow conditions and does not conform to linear flow under low-speed flow conditions. When the bottom-hole production pressure differential is increased, the flow resistance increases after the inflection point. As the bottom-hole production pressure differential continues to increase, the flow state is not affected, and the formation liquid supply capacity difference is small, which can ensure sufficient formation liquid supply. The reasonable bottom-hole production pressure differential is determined after the inflection point, and the reasonable productivity of the oil well is determined accordingly; For high-speed non-linear flow, that is, the fluid does not conform to linear flow under high-speed flow conditions and conforms to linear flow under low-speed flow conditions. When the bottom-hole production pressure differential is increased, the flow resistance increases after the inflection point, and the flow state is affected, and the formation liquid supply capacity decreases, and the formation liquid supply cannot be maintained sufficiently for a long time. The reasonable bottom-hole production pressure differential is determined before the inflection point, and the reasonable productivity of the oil well is determined accordingly; For the exponential growth type, within a certain pressure differential range, as the bottom-hole production pressure differential increases, the oil production rate increases exponentially. It is possible to enlarge the production with the choke. When determining the reasonable productivity, it is advisable to consider whether the wellbore stability and the gathering and transportation bearing capacity of the surface pipeline meet the requirements, expand the production and pressure test research with the choke, and then determine the reasonable productivity; For the transition type, as the bottom-hole production pressure differential increases, the production rate rises in a stepwise manner, and before and after the step, the oil production rate increases rapidly with the bottom-hole production pressure differential. The production of the oil well is allocated by determining the bottom-hole production pressure differential before and after the step, and the reasonable productivity is taken as the productivity corresponding to the step; 4. The device for determining the reasonable production capacity of oil wells in an oil reservoir according to claim 3, wherein, Determining the reasonable productivity for different types of single wells includes: Determining the relationship curve between the single well type and the single well; Determining the reasonable productivity according to the single well type and the corresponding relationship curve; 5. An electronic device, characterized in that, The electronic device includes: A memory storing executable instructions; A processor that runs the executable instructions in the memory to implement the method for determining the reasonable productivity of the reservoir oil well according to claim 1 or 2; 6. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores a computer program, and when the computer program is executed by a processor, it implements the method for determining the reasonable productivity of the reservoir oil well according to claim 1 or 2;

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