A method and system for calculating the amount of flow regulating channel plugging agent used in fracture-cavity oil reservoir

Abstract

The present invention discloses a method for calculating the amount of plugging agent used for flow regulation in fracture-cavity oil reservoirs, comprising: collecting tracer test data and dynamic production data of the injection and production well group of the oil reservoir unit to be studied; determining the number of flow channels of the well-to-well group with a connectable relationship in the current unit according to the tracer test data of the injection and production well group; performing injection water effect analysis on the current unit according to the dynamic production data and using reservoir engineering theory, calculating the water distribution of the unit after water injection, and further obtaining the corresponding flow channel volume; calculating the amount of plugging agent used in the specified flow regulation direction according to the flow channel volume and the number of flow channels of each well-to-well group, using the ratio of the number of flow channels to be regulated in the specified flow regulation direction to the number of all flow channels related to the current flow regulation direction. The present invention calculates the dynamic amount of plugging agent used in real time, improves the calculation accuracy and speed, and has certain promotion value.

Description

Technical Field

[0001] The invention relates to the technical field of flow regulation in fracture-cavity oil reservoirs, and in particular to a method and a system for calculating the dosage of a flow regulation channel plugging agent in fracture-cavity oil reservoirs. Background Art

[0002] Carbonate fracture-cave reservoirs are a special type of reservoirs, whose storage space is mainly fractures and caves, and whose matrix has basically no fluid seepage capacity. The flow of fluid in the reservoir mainly depends on the communication between fractures and caves, caves and caves, and fractures and fractures. Due to the random distribution of fractures and caves, a good fracture-cave system is generally not formed. Therefore, the heterogeneity of carbonate fracture-cave reservoirs is particularly strong.

[0003] Due to the particularity and heterogeneity of the reservoir, fracture-cave reservoirs are generally developed in a depletion-type manner in the early stage. The decrease in formation pressure will inevitably lead to the closure of fractures and the reduction of the conductivity between the connected media. In the development process of fracture-cave reservoirs, the near-well caves are used to a high degree. Due to the decrease in formation pressure, the physical properties of the reservoirs connecting the near-well and far-well caves deteriorate, preventing the crude oil in the far-end caves from flowing to the bottom of the well. Water injection is used to increase the formation energy and prevent the flow capacity of the connected reservoir from being lower than the critical value. Especially when the connecting medium is a fracture, it is necessary to avoid the phenomenon of the fracture opening being reduced or even closed due to the decrease in formation pressure. Improving the water drive function and making it more fully used are important directions for stabilizing production in old areas. However, in the process of water drive, the injected water is not displaced along the ideal design route. Often due to the development of underground fractures or faults, the proportion of lateral displacement is generally still very low, and the plane water distribution is low.

[0004] From the perspective of the geological background and fracture-cavity structure of fracture-cavity reservoirs, the injected water fails to effectively displace crude oil, which is mainly manifested in the following aspects: ① The injected water flows into the bottom water along the fault / underground river, the vertical sweep of the injected water is high (the invalid volume of the injected water is large), the plane sweep is low, and the plane sweep efficiency is low; ② When one injection and one production, the main channel of the injection and production well group is the dominant water flow channel, which is prone to water channeling, resulting in the secondary channel not being swept; ③ When one injection and multiple production, the injected water channels along the dominant channel direction, and the inferior channel direction is not swept, which is similar to the one injection and one production situation. In view of this, it is generally necessary to adjust the flow channel of the injected water, improve the plane sweep efficiency of the injected water, and increase the plane water distribution. However, when injecting the flow regulating agent, how much flow regulating agent is used is an urgent problem to be solved.

[0005] In the existing water injection profile control technology, although solutions are provided for quantitatively calculating the amount of flow channel plugging agents for oil reservoirs, these solutions have the disadvantages of long algorithm time consumption, the need to add special instruments, few reference factors when calculating the amount of plugging agents, which makes the results one-sided, and the plugging agent dosage calculation scheme does not conform to the actual situation during implementation, resulting in waste of profile control plugging agents. Therefore, the existing technology needs to provide a new solution for the amount of flow channel plugging agents suitable for fracture-cavity oil reservoirs to solve one or more of the aforementioned technical problems. Summary of the invention

[0006] In order to solve the above technical problems, the present invention provides a method for calculating the amount of plugging agent for flow regulation in fracture-cavity oil reservoirs, comprising: collecting tracer test data and dynamic production data of the injection and production well group of the reservoir unit to be studied; determining the number of flow channels of the well-to-well group with a connectable relationship in the current reservoir unit according to the tracer test data of the injection and production well group; performing an injection water effectiveness analysis on the current unit according to the dynamic production data and using reservoir engineering theory, calculating the water distribution of the unit after water injection, and further obtaining the corresponding flow channel volume; calculating the amount of plugging agent in the specified flow regulation direction according to the flow channel volume and the number of flow channels of each well-to-well group and using the ratio of the number of flow channels to be regulated in the specified flow regulation direction to the number of all flow channels related to the current flow regulation direction.

[0007] Preferably, the method further comprises: verifying the number of flow passages in each inter-well group using a Fourier transform method based on the dynamic production data.

[0008] Preferably, a curve of water cut variation over time is extracted from the dynamic production data, and the current water cut variation curve is subjected to Fourier transform processing to obtain a corresponding spectrum diagram; the number of peaks of the water cut spectrum diagram is counted according to the water cut spectrum diagram, and the current number of flow channels is verified by combining the current peak number statistical results and the connectivity analysis information of each well group.

[0009] Preferably, the step of determining the number of flow paths of the inter-well groups having a connectable relationship within the current reservoir unit based on the tracer test data of the injection and production well groups includes: determining the tracer production curve corresponding to each pair of inter-well groups based on the tracer test data of the injection and production well groups; and determining the number of flow paths of each pair of inter-well groups based on the number of peaks of the tracer production curve.

[0010] Preferably, the corresponding water splitting rate is calculated according to the water injection volume corresponding to the current water injection time and the water splitting volume; and the flow channel volume of the current unit is obtained according to the water splitting rate, combined with the water injection speed and the breakthrough time of the injected water.

[0011] Preferably, the normal liquid production volume corresponding to the first production time before water injection is calculated; based on the normal liquid production volume, combined with the liquid production volume of the entire production stage, the liquid production volume per unit pressure drop before water injection and the production pressure change value after water injection at the first production time, the stage liquid production volume of each pressure increase section and each pressure drop section after water injection is calculated; the liquid production volumes of each stage are integrated to generate the water distribution volume of the current unit.

[0012] Preferably, the process of calculating the amount of plugging agent under a specified flow regulation direction includes: determining the target well under the current flow regulation direction, and the first type of well group that can form a connectable relationship with the target well, and calculating the sum of the number of flow channels of all first type well groups to obtain the total number of flow channels of the target well; referring to the connectivity analysis information of each well group, determining the actual number of connected flow channels of each pair of first type well groups, and adding them to obtain the number of well group connected directions; determining the number of flow channels that need to be regulated in the current flow regulation direction, and based on this, combining the total number of flow channels of the target well, the number of well group connected directions and the flow channel volume, calculating the amount of flow regulation channel plugging agent in the current flow regulation direction.

[0013] Preferably, the amount of plugging agent in a specified flow regulation direction is calculated using the following expression:

[0014]

[0015] Among them, V d represents the amount of flow regulating channel plugging agent used in the current flow regulating direction, M represents the total number of flow channels in the target well, F represents the number of flow channels that need to be regulated in the current flow regulating direction, N represents the number of connecting directions of the well group, and V represents the volume of the flow channel.

[0016] On the other hand, the present invention also provides a system for calculating the amount of plugging agent used for flow regulation in fracture-cavity oil reservoirs, comprising: a data collection module, which is configured to collect tracer test data and dynamic production data of the injection and production well groups of the oil reservoir unit to be studied; an inter-well flow channel number generation module, which is configured to determine the number of flow channels of the inter-well groups with a connectable relationship in the current oil reservoir unit according to the tracer test data of the injection and production well groups; a flow channel volume generation module, which is configured to perform an injection water effectiveness analysis on the current unit based on the dynamic production data and reservoir engineering theory, calculate the water distribution of the unit after water injection, and further obtain the corresponding flow channel volume; a plugging agent dosage generation module, which is configured to calculate the amount of plugging agent in the specified flow regulation direction according to the flow channel volume and the number of flow channels of each inter-well group, using the ratio of the number of flow channels to be regulated in the specified flow regulation direction to the number of all flow channels related to the current flow regulation direction.

[0017] Preferably, the system further comprises: an inter-well flow channel number verification module, which is configured to verify the number of flow channels of each inter-well group based on the dynamic production data using a Fourier transform method.

[0018] Compared with the prior art, one or more embodiments of the above scheme may have the following advantages or beneficial effects:

[0019] The present invention discloses a method and system for calculating the amount of flow regulating channel plugging agent used in fracture-cavity oil reservoirs. The method and system combine field data, reservoir engineering and seepage mechanics theory, and on the basis of the collection and collation of data such as reservoir geology, production dynamics, well history of carbonate fracture-cavity oil reservoirs, and comprehensive interpretation of tracers, calculate the water separation rate and flow channel size of the injected water during water injection, and then determine the amount of flow regulating channel plugging agent used, thereby establishing a calculation model, calculation method and calculation process for the amount of flow regulating channel plugging agent used that is specifically suitable for carbonate fracture-cavity oil reservoirs. The present invention is suitable for the water injection stage of carbonate fracture-cavity oil reservoir development, especially the stage where the water drive effect becomes poor after the injection-production well group is effective. When water channeling occurs in the injection-production well group and the dominant channel of the injected water needs to be adjusted, the method can be used to calculate the dynamic amount of plugging agent in real time according to the production situation of the production well, and the calculated amount of plugging agent is time-effective. In addition, the present invention improves the calculation accuracy and speed of the amount of flow channel plugging agent used in carbonate fracture-cavity oil reservoirs, ensures the accuracy of the calculation results, and has certain promotion value. In addition, the present invention also provides certain technical support for the calculation of water distribution between injection and production well groups, which helps to better understand the size of underground flow channels.

[0020] Other features and advantages of the present invention will be described in the following description, and partly become apparent from the description, or understood by practicing the present invention. The purpose and other advantages of the present invention can be realized and obtained by the structures particularly pointed out in the description, claims and drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] The accompanying drawings are used to provide a further understanding of the present invention and constitute a part of the specification. Together with the embodiments of the present invention, they are used to explain the present invention and do not constitute a limitation of the present invention. In the accompanying drawings:

[0022] Figure 1 This is a step diagram of a first example of a method for calculating the dosage of a flow regulating and plugging agent for a fracture-vuggy oil reservoir according to an embodiment of the present application.

[0023] Figure 2 This is a step diagram of a second example of a method for calculating the amount of flow regulating and plugging agent for a fracture-vuggy oil reservoir according to an embodiment of the present application.

[0024] Figure 3It is a schematic diagram of the principle of determining the number of flow channels in the interwell group in the method for calculating the amount of flow channel plugging agent for fracture-cavity oil reservoirs in an embodiment of the present application.

[0025] Figure 4 It is a schematic diagram of a tracer output curve in a method for calculating the dosage of a flow regulating and plugging agent for a fracture-vuggy oil reservoir in an embodiment of the present application.

[0026] Figure 5 This is an example of a water content spectrum diagram after Fourier time-varying processing in the method for calculating the dosage of flow regulating and plugging agent for fracture-cavity oil reservoirs in an embodiment of the present application.

[0027] Figure 6 It is a schematic diagram of the relationship between the injection and production well groups in Example 1 of the method for calculating the dosage of the flow regulating channel plugging agent in the fracture-cavity oil reservoir in the embodiment of the present application.

[0028] Figure 7 It is a schematic diagram of the tracer production curve between the I1-P1 injection and production wells in Example 1 of the method for calculating the dosage of the flow regulating and plugging agent in the fracture-vuggy oil reservoir in the embodiment of the present application.

[0029] Figure 8 It is a schematic diagram of a curve showing the change of water content over time in the P1 production well in Example 1 of the method for calculating the dosage of the flow regulating and plugging agent for fracture-cavity oil reservoirs in the embodiment of the present application.

[0030] Fig. 9 It is a schematic diagram of the Fourier time-varying spectrum of the P1 production well in Example 1 of the method for calculating the dosage of the flow regulating and plugging agent in the fracture-cavity oil reservoir according to the embodiment of the present application.

[0031] Fig.10 It is a schematic diagram of a curve showing the daily liquid production of the P1 production well changing over time in Example 1 of a method for calculating the dosage of a flow regulating and plugging agent for a fracture-vuggy oil reservoir according to an embodiment of the present application.

[0032] Fig.11 It is a schematic diagram of a curve showing the daily water injection volume of the P1 production well changing over time in Example 1 of a method for calculating the dosage of a flow regulating and plugging agent for a fracture-vuggy oil reservoir in an embodiment of the present application.

[0033] Fig.12 This is a schematic diagram of the effectiveness analysis between the I1-P1 injection and production wells in Example 1 of the method for calculating the dosage of the flow regulating and plugging agent in the fracture-cavity oil reservoir in the embodiment of the present application.

[0034] Fig.13 It is a module block diagram of a first example of a system for calculating the amount of flow regulating and plugging agent for fracture-cavity oil reservoirs according to an embodiment of the present application.

[0035] Fig.14 It is a module block diagram of a second example of a system for calculating the amount of flow regulating and plugging agent for fracture-cavity oil reservoirs according to an embodiment of the present application. DETAILED DESCRIPTION

[0036] The following will describe the implementation methods of the present invention in detail with reference to the accompanying drawings and embodiments, so that the implementation process of how the present invention applies technical means to solve technical problems and achieve technical effects can be fully understood and implemented accordingly. It should be noted that as long as there is no conflict, the various embodiments of the present invention and the various features in the embodiments can be combined with each other, and the technical solutions formed are all within the protection scope of the present invention.

[0037] In addition, the steps shown in the flowchart of the accompanying drawings can be executed in a computer system such as a set of computer executable instructions. Also, although a logical sequence is shown in the flowchart, in some cases, the steps shown or described can be performed in a sequence different from that here.

[0038] Carbonate fracture-cave reservoirs are a special type of reservoirs, whose storage space is mainly fractures and caves, and whose matrix has basically no fluid seepage capacity. The flow of fluid in the reservoir mainly depends on the communication between fractures and caves, caves and caves, and fractures and fractures. Due to the random distribution of fractures and caves, a good fracture-cave system is generally not formed. Therefore, the heterogeneity of carbonate fracture-cave reservoirs is particularly strong.

[0039] Due to the particularity and heterogeneity of the reservoir, fracture-cave reservoirs are generally developed in a depletion-type manner in the early stage. The decrease in formation pressure will inevitably lead to the closure of fractures and the reduction of the conductivity between the connected media. In the development process of fracture-cave reservoirs, the near-well caves are used to a high degree. Due to the decrease in formation pressure, the physical properties of the reservoirs connecting the near-well and far-well caves deteriorate, preventing the crude oil in the far-end caves from flowing to the bottom of the well. The well-controlled reserves are large, but the degree of use is low. The decrease in formation pressure affects the fluidity of the fluid in the link. Water injection is used to increase the formation energy to prevent the flow capacity of the linked reservoir from being lower than the critical value, especially when the linking medium is a fracture, it is necessary to avoid the phenomenon of the fracture opening being reduced or even closed due to the decrease in formation pressure. After the formation energy decreases, energy is added to the formation. With the increase in water injection, the formation pressure is partially restored, and the far-end caves will be effectively used. Only by utilizing the remote karst bodies can we ensure stable and increased production of oil wells without drilling new wells, thereby maintaining stable production of the entire unit. Water drive controls large reserves and accounts for a high proportion, which is the main resource basis for long-term stable production. Improving the use of water drive and making it more fully utilized are important directions for stable production in old areas. However, during the water drive process, the injected water is not displaced along the ideal design route. Often due to the development of underground cracks or fractures, the proportion of lateral displacement is generally still very low, and the plane water distribution is low.

[0040] From the perspective of the geological background and fracture-cavity structure of fracture-cavity reservoirs, the injected water fails to effectively displace crude oil, which is mainly manifested in the following aspects: ① The injected water flows into the bottom water along the fault / underground river, the vertical sweep of the injected water is high (the invalid volume of the injected water is large), the plane sweep is low, and the plane sweep efficiency is low; ② When one injection and one production, the main channel of the injection and production well group is the dominant water flow channel, which is prone to water channeling, resulting in the secondary channel not being swept; ③ When one injection and multiple production, the injected water channels along the dominant channel direction, and the inferior channel direction is not swept, which is similar to the one injection and one production situation. In view of this, it is generally necessary to adjust the flow channel of the injected water, improve the plane sweep efficiency of the injected water, and increase the plane water distribution. However, when injecting the flow regulating agent, how much flow regulating agent is used is an urgent problem to be solved.

[0041] When realizing the present invention, the inventors found in the research of domestic and foreign literature that the profile adjustment amount is generally optimized by evaluating the profile adjustment effect of water injection wells, and the evaluation methods can be divided into four categories, namely fuzzy mathematical analysis method, well test analysis method, potential method well-to-well detection technology and single factor evaluation method. Among them, the fuzzy mathematical analysis method can comprehensively evaluate the profile adjustment effect by evaluating multiple factors at the same time and optimizing the weight of each factor. Fuzzy mathematics can qualitatively evaluate the profile adjustment effect of injection wells, but it cannot quantify the amount of profile adjustment; the well test analysis method can quantify the amount of profile adjustment, but it needs to establish a numerical model and perform historical fitting, which is time-consuming and cannot guide production in time; the potential method of well detection technology has high accuracy and fast speed, but it needs to set up special instruments and equipment at the well site, and has high requirements for injection fluid, because this method needs to pump high ionization energy injection fluid into the formation. The requirements for equipment, facilities and injection fluid limit the application of this method; the single factor evaluation method mainly evaluates the influencing factors of profile adjustment individually, which can well understand the importance of single factors to profile adjustment, but does not consider the mutual influence and superposition between factors. The optimized amount of profile adjustment is one-sided and difficult to promote.

[0042] In addition, when realizing the present invention, the inventor found in domestic and foreign patent research that the patent application involving the injection water profile control is related to the invention purpose involved in this application. The patent mainly uses tracer interpretation data, well logging interpretation data and water absorption profile data to comprehensively determine the profile control dosage of the injection well, but when determining the profile control radius, the patent simply uses the injection-production well spacing between the injection well and the oil production well as the profile control radius. When the selected profile control object is one injection and one production, it is acceptable to use the profile control radius as the injection-production well spacing. However, when the well network is not one injection and one production, but one injection and multiple production or multiple injections and multiple production, the weight of the injected profile control plugging agent in each direction must be considered. In actual application, the profile control radius is not so large. Even if an advantageous injection and production channel has been formed between the injection and production wells, the plugging agent cannot be completely pumped into this channel. Under this condition, the well spacing is used as the profile control radius, which exaggerates the profile control volume and increases the amount of profile control plugging agent. Even if the area is split later, when calculating the amount of plugging agent in each direction in the early stage, the profile control volume is calculated as a cylinder. Then, there must be overlapping areas in the profile control volumes in different directions of the same well, resulting in a waste of profile control plugging agents, which is not conducive to economical and efficient development.

[0043] Therefore, it is necessary to re-establish a method for calculating the amount of profile adjustment plugging agent. In order to solve one or more of the above technical problems, the present application proposes a method and system for the amount of flow channel adjustment plugging agent suitable for fracture-cavity oil reservoirs. The method and system include: collecting tracer test data and dynamic production data of the injection and production well group of the unit to be studied; determining the number of dynamic flow channels of each inter-well group based on the tracer interpretation report; processing dynamic production data based on Fourier time-varying theory to verify the number of dynamic flow channels of each inter-well group; calculating the water distribution volume and channel volume based on reservoir engineering methods; finally, based on the size of the flow channel volume, according to the ratio of the number of flow channels to be adjusted and the total flow channels corresponding to the target well in the current flow adjustment direction, determine the amount of flow channel adjustment plugging agent. In this way, a method for calculating the amount of flow channel adjustment plugging agent with high calculation accuracy and fast calculation speed is provided, which can calculate the dynamic amount of plugging agent in real time according to the actual production situation of the production well. The calculated amount of plugging agent is time-effective and helps to better understand the size of underground flow channels.

[0044] Embodiment 1

[0045] Figure 1 This is a step diagram of the first example of the method for calculating the amount of flow regulating and plugging agent for fracture-cavity oil reservoirs according to the embodiment of the present application. Figure 1 A first example of a method for calculating the amount of plugging agent for regulating flow passages in a fracture-vuggy oil reservoir according to an embodiment of the present invention (hereinafter referred to as “the method for calculating the amount of plugging agent”) is described.

[0046] Step S110 collects the tracer test data and dynamic production data of the injection and production well group of the reservoir unit to be studied. In step S110, it is necessary to collect the tracer test data of the injection and production well group of the reservoir unit to be studied, the distribution location information of the injection wells and the recovery wells in the unit, the field data, the basic information of the injection and production well group (for information content, see Table 1 below), and the dynamic production data information of all the recovery wells in the unit, so as to enter step S120.

[0047] Step S120 determines the number of flow paths of the well-to-well group with a connectable relationship in the current reservoir unit according to the tracer test data of the injection and production well group of the current reservoir unit to be studied collected in step S110. In the embodiment of the present invention, the well-to-well group with a connectable relationship (hereinafter referred to as "well-to-well group") refers to a combination of two wells with connectability in the current reservoir unit to be studied, such as a recovery well and a water injection well, or two recovery wells at different locations. In addition, two wells that cannot be connected or have a low probability of connection, such as a water injection well and a water injection well, are regarded as a combination of two wells with no connectivity.

[0048] In step S120, it is necessary to determine all well groups (well pairs) with a connectable relationship in the current unit based on the tracer test data of the injection and production well groups, and determine the number of (dynamic) flow channels between each pair of well groups. Specifically, it is necessary to first determine the tracer production curve corresponding to each pair of well groups in the recovery well based on the tracer test data of the injection and production well groups of the current unit, and then analyze the number of peaks of these tracer production curves, and determine the number of flow channels corresponding to each pair of well groups and / or the physical property parameters of each flow channel based on the number of peaks of these tracer production curves.

[0049] Figure 3 Schematic diagram of the principle of determining the number of interwell flow channels in the method for calculating the amount of flow channel plugging agent for fracture-cavity oil reservoirs in the embodiment of the present application. Figure 3 As shown in the figure, due to the strong heterogeneity of fracture-cavity reservoirs, when conducting numerical analysis of tracers, it can be assumed that there are n flow channels between the injection and production wells or between two production wells. After tracer analysis, the physical property parameters k of each flow channel can be obtained. i ,φ i ,V i Among them, the physical parameters include: the permeability k of the i-th channel i , represents the porosity of the i-th channel φ i , represents the flow volume V of the i-th channel i .

[0050] Furthermore, due to the different physical properties of each flow channel, the tracer always first penetrates into the production well (recovery well) along the high permeability channel, so a peak will appear on the tracer curve produced from the production well. Since each high permeability channel has a peak in the tracer output curve, and the peaks appear at different times, the tracer output curve between multi-channel injection and production wells will have multiple peaks. Each peak represents a high permeability channel, and the steeper the peak, the higher the permeability of the corresponding channel.

[0051] Figure 4 It is a schematic diagram of a tracer output curve in a method for calculating the dosage of a flow regulating and plugging agent for a fracture-vuggy oil reservoir in an embodiment of the present application. Figure 4 The tracer production curve of a certain production well is shown, and the tracer production curves of three pairs of well groups (curve 1, curve 2 and curve 3) are specifically shown. Curve 1 and curve 2 both indicate that the pair of well groups has one flow channel, and curve 3 indicates that the pair of well groups has two channels. By analogy, the number of peaks of the tracer production curve for each pair of well groups corresponds to the number of corresponding channels between the injection and production wells or between two recovery wells. According to the actual tracer production curve, the number of flow channels between the injection and production well groups can be determined.

[0052] It should be noted that, in the embodiment of the present invention, the number of flow channels for each pair of well groups determined refers to the sum of the number of actually connected flow channels and the number of disconnected flow channels. For example: there are n flow channels between production well A and production well B, n = n1 + n2, where n1 represents the total number of actually connected flow channels in the current well group, and n2 represents the total number of actually disconnected flow channels in the current well group.

[0053] After determining the number of flow channels of each pair of well groups with a connectable relationship, the process proceeds to step S130. Step S130 uses reservoir engineering theory to analyze the effectiveness of injected water on the current unit to be studied based on the dynamic production data of the current unit to be studied collected in step S110, calculates the water distribution of the unit to be studied after water injection, and further obtains the corresponding flow channel volume (for the unit).

[0054] In step S130, the water injection effect analysis of the current unit to be studied will be conducted based on the dynamic production data of the current unit to be studied and reservoir engineering theory will be used to calculate the water distribution of the unit to be studied after water injection. Specifically, first (the first step) the normal liquid production volume corresponding to the first production time before water injection construction is calculated. In other words, since the current unit has already started production before water injection construction, it is necessary to first predict the liquid production volume generated by the current unit in the first production time before water injection construction. Among them, the first production time refers to the production time (water injection time) corresponding to the production stage after water injection.

[0055] Then, (the second step) according to the calculated normal liquid production, combined with the liquid production of the entire production stage (the sum of the production time before and after water injection), the unit pressure drop liquid production before water injection, and the pressure change value of the production well at the first production time after water injection, calculate the stage liquid production of each pressure increase section and each pressure drop section after water injection. It should be noted that after the water injection construction, the production pressure of the entire unit will continue to change with the advancement of production time, so that the entire production stage will be divided into a complete production stage in which the pressure increase stage and the pressure drop stage are continuously alternating. Therefore, in this step, it is necessary to calculate the stage liquid production of each pressure increase section and each pressure drop section after water injection. Finally, the liquid production of each stage is integrated to obtain the water distribution corresponding to the current reservoir unit to be studied after water injection construction.

[0056] In actual application, since the recovery well will produce normally before water flooding (before water injection construction), when there are no other production-increasing measures for the recovery well, the unit pressure drop oil production before water injection is a fixed value, which is recorded as the unit pressure drop liquid production. The unit pressure drop liquid production is expressed by the following expression:

[0057]

[0058] Among them, J q It is expressed as the amount of liquid produced per unit pressure drop before water injection, Q t It represents the stage liquid production volume corresponding to the production time t0 before water injection, ΔP t It represents the pressure drop of the production pressure corresponding to the production time t0 before water injection.

[0059] After the water injection construction, when the front position of the injected water reaches the production well, some development parameters of the production well will change due to the replenishment of formation energy, such as: liquid production, oil production, water content, oil pressure, etc. Since the water injected into the injection well cannot completely displace the crude oil, a part of the water will be ineffective. Then the part of the injected water that effectively displaces the crude oil is defined as the water split of the injected water, recorded as Q f In the embodiment of the present invention, the water distribution amount is calculated using the following expression:

[0060] Q f =Q l +ΔP·J q -Q y (2)

[0061] Among them, Q f represents the water distribution of the entire unit at the first production time t' after water injection, Q l represents the liquid production volume at the first production time t' after water injection, ΔP represents the production pressure change value corresponding to the first production time t' after water injection, Q yrepresents the (predicted) normal production volume of the production well at the first production time t′ before water injection. The predicted value can be calculated based on the product of the average oil production before water injection and the production time before water injection, or predicted based on the production decline model. In this way, after substituting the production time corresponding to each pressure increase stage or the production time corresponding to each pressure drop stage into the first production time, the embodiment of the present invention can use the above expressions (1) and (2) to calculate the stage production volume of each pressure increase section and each pressure drop section after water injection.

[0062] More specifically, when the production time corresponding to the entire production stage after water injection is large enough, the pressure increases first and then decreases during the production time period, such as: the pressure increases at (t1, t2) during the entire production time after water injection, and decreases at (t2, t3). Then, under the above conditions, it is necessary to divide the entire production time after water injection into two sections, calculate the water distribution corresponding to the current pressure increase section and the pressure drop section, and use the following expression to calculate the water distribution corresponding to the current pressure increase section and the current pressure drop section:

[0063]

[0064] Among them, Q f1 Indicates the water volume in the pressure increase section, Q l1 represents the stage liquid production volume of the production time (t1, t2) after water injection, ΔP1 represents the pressure change value (pressure increase value) corresponding to the production time (t1, t2) after water injection, Q y1 represents the normal liquid production volume at production time (t1, t2) before water injection, Q f2 Indicates the water volume in the pressure drop section, Q l2 represents the stage liquid production volume of the production time (t2, t3) after water injection, ΔP2 represents the pressure change value corresponding to the production time (t2, t3) after water injection (when the change value of the production pressure is negative, it means that after water injection, the pressure does not increase but decreases. At this time, ΔP takes the absolute value of the pressure drop value), Q y2 It represents the normal liquid production volume at the production time (t2, t3) before water injection. Finally, the water distribution volume of the current pressure increase section and the water distribution volume corresponding to the current pressure drop section are added together to obtain the unit water distribution volume of the entire current production stage after water injection. The water distribution volume of the entire unit is calculated using the following expression:

[0065] Q f =Q f1 +Q f2 (4)

[0066] Therefore, in an embodiment of the present invention, when the entire production time after water injection (complete production time) includes multiple pressure increase sections and pressure drop sections, the water distribution volume of each pressure increase section and each pressure drop section is calculated respectively using the above expressions (1) and (2), and then the total water distribution volume is equal to the sum of the water distribution volumes of all pressure change sections to obtain the water distribution volume of the current unit during the complete production time.

[0067] Next, in step S130, when the calculation of the unit water distribution volume is completed, the volumes of all flow channels involved in multiple pairs of well groups in the current unit are calculated according to the calculated unit water distribution volume, which is recorded as the unit flow channel volume.

[0068] In the embodiment of the present invention, when calculating the flow channel volume of the entire unit, it is necessary to first calculate the corresponding water split rate based on the water injection volume and water split volume corresponding to the current water injection time. That is to say, it is necessary to first obtain the cumulative water injection volume corresponding to the actual water injection duration (the water injection time corresponding to the water injection construction) for the current reservoir unit to be studied, and combine the unit water split volume of the calculated complete production time after water injection to calculate the water split rate of the current unit after water injection. Among them, the water split rate is calculated using the following expression:

[0069]

[0070] Among them, I f represents the (unit) water splitting rate corresponding to the first production time t' after water injection, Q I It represents the (cumulative) water injection volume corresponding to the injection time of the injection well (i.e. the first production time after water injection) t′. Then, after the calculation of the unit water split rate is completed using the above expression (5), the flow channel volume of the current unit is obtained according to the current water split rate data, combined with the water injection speed of the water injection construction and the breakthrough time of the injected water.

[0071] In actual application, the breakthrough time of injected water in water injection construction is the time T when the injected water reaches the bottom of the well. There are two ways to determine the T value: first, it is obtained based on the increase in the water content of the production well. When the water content increases sharply, that is, the time corresponding to the start of water injection construction to the appearance of water in the production well, the breakthrough time of injected water is obtained; second, it is calculated according to the relevant formula of the water drive front breakthrough theory. Based on the principle of material balance, in the implementation of the present invention, the unit flow channel volume is calculated using the following expression:

[0072] V=v w TI f (6)

[0073] Where V represents the flow channel volume of the current unit, v w represents the injection rate and T represents the breakthrough time of the injected water.

[0074] In this way, the embodiment of the present invention calculates the flow channel volume of the entire unit using the above step S130, and then proceeds to step S140.

[0075] Step S140 calculates the amount of plugging agent in the specified flow adjustment direction according to the flow channel volume obtained in step S130 and the number of flow channels of each pair of well-to-well groups obtained in step S120, and according to the ratio of the number of flow channels to be adjusted in the specified flow adjustment direction to the number of all flow channels related to the current flow adjustment direction. In an embodiment of the present invention, the calculation result of the amount of plugging agent is for the amount in the specified flow adjustment direction, that is, the amount of plugging agent required for flow adjustment transformation from the flow adjustment starting well to the flow adjustment target well in a certain specified well-to-well group. For example: in the current reservoir unit to be studied, there are recovery well A and recovery well B, and these two recovery wells constitute a pair of well-to-well groups with a connectable relationship. If you want to transform the flow adjustment channel between recovery well A and recovery well B, then the specified flow adjustment direction refers to the direction formed by recovery well A to recovery well B, where recovery well A is the starting well and recovery well B is the target well.

[0076] Specifically, in step S140, (step S1401, not shown), it is necessary to first determine the target well in the current specified flow adjustment direction and the first type of well-to-well group in the current unit that can form a connectable relationship with the target well, and then calculate the sum of the number of flow channels of all the first type of well-to-well groups to obtain the total number of flow channels (M) of the target well. In an embodiment of the present invention, with the target well as the center, traverse the other wells in the current unit except the target well, determine all water injection wells and all production wells (recovery wells) that can form a connectable relationship with the target well, so that these water injection wells or production wells that can form a connectable relationship with the target well, and the well-to-well groups formed after being combined with the target well respectively, are recorded as the first type of well-to-well group. Therefore, according to the number of flow channels of all well-to-well groups in the current unit obtained in step S120, the number of flow channels of all the first type of well-to-well groups is added to obtain the total number of flow channels (M) of the target well, thereby realizing the statistics of all flow channels related to the target well (including flow channels with actual connection relationship and disconnected relationship).

[0077] After determining the total number of flow channels of the current target well, (step S1402, not shown) refer to the actual connectivity analysis information of all inter-well groups in the unit, determine the actual number of connected flow channels of each pair of first-type inter-well groups, and add them to obtain the number of well group connection directions (N). Specifically, in the actual application process, since the number of flow channels of each inter-well group determined in step 120 does not take into account the actual connectivity of each flow channel between the corresponding well groups (it may be connected or not), therefore, in calculating the number of well group connection directions, it is necessary to first understand the actual connectivity of the flow channels involved in all pairs of inter-well groups in the current reservoir unit to be studied.

[0078] Specifically, in the process of calculating the number of well group connection directions, after referring to the actual connectivity analysis information of all well groups in the unit, it is necessary to determine the number of actually connected flow channels among the several flow channels corresponding to each pair of first-type well groups, so as to obtain the corresponding actual number of connected flow channels for each pair of first-type well groups, and then, add these actual numbers of connected flow channels to obtain the number of well group connection directions (N).

[0079] After obtaining the total number of flow channels of the target well and the number of well group connection directions, (step S1403, not shown), continue to determine the number of flow channels (F) that need to be regulated in the current flow regulation direction. Based on this, combined with the total number of flow channels of the target well (M), the number of well group connection directions (N) and the unit flow channel volume obtained in step S130, calculate the amount of flow regulation channel plugging agent in the current specified flow regulation direction. The following expression is used to calculate the amount of flow regulation channel plugging agent:

[0080]

[0081] Among them, V d It indicates the amount of flow regulating channel plugging agent used in the current flow regulating direction, M indicates the total number of flow channels in the target well, F indicates the number of flow channels that need to be regulated in the current flow regulating direction (the number of flow channels to be regulated), N indicates the number of connecting directions of the well group, and V indicates the (unit) flow channel volume.

[0082] In this way, when water breakthrough occurs in the injection-production well group and the dominant channel of the injected water needs to be adjusted, the embodiment of the present invention uses the plugging agent dosage calculation method adopted in the above steps S110 to S140 to implement the flow channel adjustment construction, and specifically calculates the dynamic plugging agent dosage in real time according to the dynamic production situation of the production well, and the calculated plugging agent dosage is time-effective.

[0083] Embodiment 2

[0084] Based on the above-mentioned first embodiment, in order to ensure the accuracy of the number of flow channels of each pair of inter-well groups in the current reservoir unit, the method for calculating the amount of plugging agent provided in the embodiment of the present invention further includes a flow channel number verification step. Figure 2 This is a step diagram of a second example of the method for calculating the amount of flow regulating and plugging agent for fracture-cavity oil reservoirs according to an embodiment of the present application. Figure 2 The second example of the method for calculating the amount of plugging agent according to the embodiment of the present invention is described in detail.

[0085] Step S210 collects the tracer test data and dynamic production data of the injection and production well group of the reservoir unit to be studied. Then, step S220 determines the number of flow channels of the inter-well group with a connectable relationship in the current reservoir unit according to the tracer test data of the injection and production well group obtained in step S210. Next, step S230 verifies the number of flow channels of each inter-well group determined in step S220 according to the dynamic production data obtained in step S210 using the Fourier transform method. After the verification is passed, step S240 performs an injection water effect analysis on the current unit according to the dynamic production data obtained in step S210 and reservoir engineering theory, calculates the water distribution of the unit after water injection, and further obtains the corresponding flow channel volume. Finally, step S250 calculates the amount of plugging agent under the specified flow adjustment direction according to the (unit) flow channel volume obtained in step S240 and the number of flow channels of each inter-well group verified in step S230, using the ratio of the number of flow channels to be adjusted under the specified flow adjustment direction to the number of all flow channels related to the current flow adjustment direction.

[0086] It should be noted that, in this embodiment, step S210 is similar to the method described in step S110, step S220 is similar to the method described in step S120, step S240 is similar to the method described in step S130, and step S250 is similar to the method described in step S140. Therefore, the embodiment of the present invention does not elaborate on step S210, step S220, step S240 and step S250.

[0087] Step S230 verifies the number of flow channels in each well group using the Fourier transform method based on the dynamic production data obtained in step S210. As a mathematical processing method and means, Fourier transform is a very effective analysis method in the field of digital signal processing. In complex signal processing, the typical function of Fourier transform is to decompose the signal into a frequency spectrum - displaying the amplitude corresponding to the frequency. This method can convert the signal in the time domain into the frequency domain for analysis (forward transform), or convert the signal in the frequency domain into the signal in the time domain for analysis (inverse transform).

[0088] In the process of reservoir seismic inversion, Fourier transform is introduced to process seismic reflection wave signals to obtain different reflection wave frequency distributions. In the process of implementing the present invention, the inventors found that seismic imaging obtained according to different reflection wave frequencies can be used to identify underground flow channels, such as one flow channel, two flow channels or multiple flow channels. Therefore, the magnitude of seismic wave frequency can reflect the number of underground flow channels. Therefore, the dynamic production data of production wells can be used as the output signal of the fracture-cavity oil reservoir system. By performing Fourier time-varying processing on the dynamic production data signal, the production spectrum of the production wells can be obtained, thereby quantifying the number of underground flow channels.

[0089] Specifically, in step S230, firstly, the curve of water cut variation over time is extracted from the dynamic production data of each recovery well in the current reservoir unit to be studied, and the water cut variation curve is subjected to Fourier transform processing to obtain the corresponding spectrum. Then, the number of peaks of the water cut spectrum is counted according to the water cut spectrum, so as to determine the number of flow channels of each inter-well group by combining the current peak number statistics and the connectivity analysis information of each inter-well group, so as to obtain the number of flow channels of each inter-well group determined based on the production data.

[0090] Figure 5 This is an example of a water content spectrum diagram after Fourier time-varying processing in the method for calculating the dosage of flow regulating and plugging agent for fracture-cavity oil reservoirs in an embodiment of the present application. Figure 5 The water content spectrum of a certain recovery well is shown. The number of flow channels can be determined by the amplitude peak, such as Figure 5 It can be seen that the number of underground flow channels corresponding to this well group is 1.

[0091] In addition, after obtaining the number of flow channels of each inter-well group determined based on the production data, step S230 will also compare the current number of flow channels of each inter-well group determined based on the production data with the number of flow channels of each inter-well group determined based on the tracer production curve obtained in step S220, and verify the number of flow channels of each inter-well group obtained in step S220 according to the comparison result.

[0092] Specifically, if the number of flow channels of a certain pair of inter-well groups obtained in step S220 is the same (consistent) as the number of flow channels of the same inter-well group obtained in step S230, then at this time, after verification, the number of flow channels of the inter-well group obtained in step S220 or the number of flow channels of the inter-well group obtained in step S230 can be used as the final number of flow channels for the current inter-well group, and the final number of flow channels is applied to step S250. In addition, if the number of flow channels of a certain pair of inter-well groups obtained in step S220 is different from the number of flow channels of the same inter-well group obtained in step S230, then at this time, after verification, the number of flow channels of the inter-well group obtained in step S230 is directly used as the final number of flow channels for the current inter-well group, and the current final number of flow channels is applied to step S250 (i.e., the number of flow channels of each inter-well group obtained in step S230 is used as the standard).

[0093] For example, the method for calculating the amount of plugging agent described in the second example is applied to a certain oil field unit, and the specific implementation process is as follows:

[0094] (1) Collect the basic information table of the injection and production well group in the current study block. The specific parameters are shown in Table 1. The injection and production well network diagram of the well group is shown in Figure 6 As shown ( Figure 6Schematic diagram of the relationship between injection and production well groups in Example 1 of the method for calculating the amount of flow regulating and plugging agent for fracture-cavity oil reservoirs in the embodiment of the present application).

[0095] Table 1 Basic information of injection and production well groups of a reservoir unit to be studied

[0096]

[0097]

[0098] (2) Tracer test data of the injection and production well group in the current unit, as shown in Table 2.

[0099] Table 2 Tracer test data of injection and production wells in a reservoir unit to be studied

[0100]

[0101] In Table 2, "△" indicates that no tracer response was detected during sampling, and "√" indicates that an obvious tracer response was detected. From Table 2, we can know the connectivity relationship between the injection well and the recovery well in the unit, as shown in Table 3.

[0102] Table 3 The connectivity relationship between injection wells and recovery wells in a certain reservoir unit to be studied

[0103] Injection well I1 Connectivity Injection well I2 Connectivity P1 yes P1 no P2 no P2 yes P3 no P3 yes P4 yes P4 yes

[0104] For ease of explanation, the calculation of the amount of plugging agent for adjusting the flow channel I1-P1 is taken as an example to illustrate the calculation process of the amount of plugging agent in the specified flow adjustment direction (I1-P1 direction).

[0105] The tracer production curve of well P1 is as follows: Figure 7 shown. Figure 7 This is a schematic diagram of the tracer production curve between the injection and production wells I1-P1 in Example 1 of the method for calculating the amount of flow regulating and plugging agent used in fracture-cavity oil reservoirs in the embodiment of the present application. Figure 7 It can be seen that the number of flow channels between I1-P1 is 1. The relationship between water content and time of P1 well is shown in Figure 8 As shown ( Figure 8 Schematic diagram of the water content variation curve of the P1 production well in Example 1 of the method for calculating the amount of flow regulating and plugging agent for fracture-cavity oil reservoirs in the embodiment of the present application). According to the Fourier forward transform algorithm, the water content variation curve is subjected to Fourier time-varying processing, and the transformed spectrum diagram is as follows: Fig. 9 shown. Fig. 9 This is a schematic diagram of the Fourier time-varying spectrum of the P1 production well in Example 1 of the method for calculating the amount of flow regulating and plugging agent for fracture-cavity oil reservoirs in the embodiment of the present application. Fig. 9 It can be seen that the number of flow channels between I1 and P1 is 1. Therefore, the correctness of the tracer interpretation of the I1-P1 interwell group is verified.

[0106] (3) Production curve of well P1, such as Fig.10 , 11 、12 as shown( Fig.10 It is a schematic diagram of a curve of daily liquid production of a P1 production well versus time in Example 1 of a method for calculating the amount of a flow regulating and plugging agent for a fracture-cavity oil reservoir in an embodiment of the present application; Fig.11 It is a schematic diagram of a curve of daily water injection volume versus time of a P1 production well in Example 1 of a method for calculating the dosage of a flow regulating and plugging agent for a fracture-cavity oil reservoir in an embodiment of the present application; Fig.12 This is a schematic diagram of the effectiveness analysis between the injection and production wells I1-P1 in Example 1 of the method for calculating the dosage of the flow regulating and plugging agent in the fracture-cavity oil reservoir in the embodiment of the present application). Fig.12 Through the calculation of expression (1), the unit pressure drop liquid production before water injection is 475t / MPa; through the calculation of expression (2), the unit water distribution volume is 2413m 3 ; By calculating the expression (5), the water separation rate is 9.04%. Fig.12 It can be seen that the breakthrough time of injection well I1 is 89 days, and the corresponding cumulative injection volume is 16377m 3 By calculating the expression (6), the unit flow channel volume is 1480.5m 3 Finally, by calculating expression (7), the amount of flow regulating and plugging agent in the direction of I1-P1 is 370.1m 3 .

[0107] Similarly, the amount of flow regulating channel plugging agent for the inter-well group in other directions can be obtained, and the calculation results are shown in Table 4.

[0108] Table 4 Calculation results of plugging agent dosage under different flow adjustment directions in a certain reservoir unit to be studied

[0109]

[0110] Embodiment 3

[0111] Based on the method for calculating the amount of plugging agent described in the first embodiment, the present invention also provides a system for calculating the amount of plugging agent for regulating flow in fracture-vuggy oil reservoirs (hereinafter referred to as "plugging agent amount calculation system"). Fig.13 It is a module block diagram of a first example of a system for calculating the amount of flow regulating and plugging agent for fracture-cavity oil reservoirs according to an embodiment of the present application.

[0112] like Fig.13As shown, the plugging agent dosage calculation system in the embodiment of the present invention includes: a data collection module 1301, an inter-well flow channel number generation module 1302, a flow channel volume generation module 1303 and a plugging agent dosage generation module 1304. Specifically, the data collection module 1301 is implemented according to the method described in step S110 above, and is configured to collect the tracer test data and dynamic production data of the injection and production well group of the reservoir unit to be studied; the inter-well flow channel number generation module 1302 is implemented according to the method described in step S120 above, and is configured to determine the number of flow channels of the inter-well group with a connectable relationship in the current reservoir unit according to the tracer test data of the injection and production well group; the flow channel volume generation module 1303 is implemented according to the method described in step S130 above, and is configured to analyze the effectiveness of injected water on the current unit based on the dynamic production data and reservoir engineering theory, calculate the water distribution of the unit after water injection, and further obtain the corresponding flow channel volume; the plugging agent dosage generation module 1304 is implemented according to the method described in step S140 above, and is configured to calculate the plugging agent dosage in the specified flow adjustment direction according to the flow channel volume and the number of flow channels of each inter-well group, using the ratio of the number of flow channels to be adjusted in the specified flow adjustment direction to the number of all flow channels related to the current flow adjustment direction.

[0113] Embodiment 4

[0114] Based on the method for calculating the amount of plugging agent described in the second embodiment, the present invention also provides a system for calculating the amount of plugging agent for regulating flow channels in fracture-vuggy oil reservoirs (hereinafter referred to as "plugging agent amount calculation system"). Fig.14 It is a module block diagram of a second example of a system for calculating the amount of flow regulating and plugging agent for fracture-cavity oil reservoirs according to an embodiment of the present application.

[0115] like Fig.14As shown, the plugging agent dosage calculation system in the embodiment of the present invention includes: a data collection module 1401, an inter-well flow channel number generation module 1402, an inter-well flow channel number verification module 1403, a flow channel volume generation module 1404 and a plugging agent dosage generation module 1405. Specifically, the data collection module 1401 is implemented according to the method described in step S210 above, and is configured to collect the injection and production well group tracer test data and dynamic production data of the reservoir unit to be studied; the inter-well flow channel number generation module 1402 is implemented according to the method described in step S220 above, and is configured to determine the number of flow channels of the inter-well group with a connectable relationship in the current reservoir unit according to the injection and production well group tracer test data; the inter-well flow channel number verification module 1403 is implemented according to the method described in step S230 above, and is configured to use the Fourier transform method to calculate the number of flow channels of each inter-well group according to the dynamic production data. The flow channel volume generation module 1404 is implemented according to the method described in step S240, and is configured to analyze the effectiveness of injected water on the current unit based on dynamic production data and reservoir engineering theory, calculate the water distribution of the unit after water injection, and further obtain the corresponding flow channel volume; the plugging agent dosage generation module 1405 is implemented according to the method described in step S250, and is configured to calculate the plugging agent dosage in the specified flow adjustment direction according to the flow channel volume and the number of flow channels in each inter-well group, using the ratio of the number of flow channels to be adjusted in the specified flow adjustment direction to the number of all flow channels related to the current flow adjustment direction.

[0116] The present invention discloses a method and system for calculating the amount of flow regulating channel plugging agent used in fracture-cavity oil reservoirs. The method and system combine field data, reservoir engineering and seepage mechanics theory, and on the basis of the collection and collation of data such as reservoir geology, production dynamics, well history of carbonate fracture-cavity oil reservoirs, and comprehensive interpretation of tracers, calculate the water separation rate and flow channel size of the injected water during water injection, and then determine the amount of flow regulating channel plugging agent used, thereby establishing a calculation model, calculation method and calculation process for the amount of flow regulating channel plugging agent used that is specifically suitable for carbonate fracture-cavity oil reservoirs. The present invention is suitable for the water injection stage of carbonate fracture-cavity oil reservoir development, especially the stage where the water drive effect becomes poor after the injection-production well group is effective. When water channeling occurs in the injection-production well group and the dominant channel of the injected water needs to be adjusted, the method can be used to calculate the dynamic amount of plugging agent in real time according to the production situation of the production well, and the calculated amount of plugging agent is time-effective. In addition, the present invention improves the calculation accuracy and speed of the amount of flow channel plugging agent used in carbonate fracture-cavity oil reservoirs, ensures the accuracy of the calculation results, and has certain promotion value. In addition, the present invention also provides certain technical support for the calculation of water distribution between injection and production well groups, which helps to better understand the size of underground flow channels.

[0117] The above is only a preferred specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any changes or substitutions that can be easily thought of by any person familiar with the technology within the technical scope disclosed by the present invention should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention should be based on the protection scope of the claims.

[0118] It should be understood that the embodiments disclosed in the present invention are not limited to the specific structures, processing steps or materials disclosed herein, but should be extended to equivalent substitutions of these features understood by ordinary technicians in the relevant field. It should also be understood that the terms used herein are only used for the purpose of describing specific embodiments and are not meant to be limiting.

[0119] The "one embodiment" or "embodiment" mentioned in the specification means that the specific features, structures or characteristics described in conjunction with the embodiment are included in at least one embodiment of the present invention. Therefore, the phrases "one embodiment" or "embodiment" appearing in various places throughout the specification do not necessarily refer to the same embodiment.

[0120] Although the embodiments disclosed in the present invention are as above, the contents described are only embodiments adopted for facilitating the understanding of the present invention and are not intended to limit the present invention. Any technician in the technical field to which the present invention belongs can make any modifications and changes in the form and details of the implementation without departing from the spirit and scope disclosed in the present invention, but the patent protection scope of the present invention shall still be subject to the scope defined in the attached claims.

Claims

1. A method for calculating the amount of flow regulating channel plugging agent used in fracture-cavity oil reservoirs, comprising: Collect tracer test data and dynamic production data of the injection and production well groups of the reservoir unit to be studied; Determine the number of flow paths in the well group with a connectable relationship in the current reservoir unit according to the tracer test data of the injection and production well group; According to the dynamic production data, using reservoir engineering theory, the injection water effect analysis is performed on the current unit, the water distribution volume of the unit after water injection is calculated, and the corresponding flow channel volume is further obtained; According to the flow channel volume and the number of flow channels in each inter-well group, the amount of plugging agent in the specified flow adjustment direction is calculated by using the ratio of the number of flow channels to be adjusted in the specified flow adjustment direction to the number of all flow channels related to the current flow adjustment direction, including: Determine the target well under the current flow adjustment direction and the first type of well group that can form a connectable relationship with the target well, and calculate the sum of the number of flow channels of all the first type of well groups to obtain the total number of flow channels of the target well; Referring to the connectivity analysis information of each well group, the number of actual connected flow paths of each pair of first-type well groups is determined, and the actual number of connected flow paths is added to obtain the number of well group connection directions; The number of flow channels that need to be regulated in the current flow regulation direction is determined. Based on this, the amount of flow regulation channel plugging agent in the current flow regulation direction is calculated in combination with the total number of flow channels of the target well, the number of connecting directions of the well group and the volume of the flow channels. The amount of plugging agent in the specified flow regulation direction is calculated using the following expression: Among them, V d It represents the amount of flow regulating channel plugging agent used in the current flow regulating direction, M represents the total number of flow channels in the target well, F represents the number of flow channels to be regulated in the current flow regulating direction, N represents the number of well group connection directions, and V represents the volume of the flow channel.

2. The method according to claim 1, characterized in that The method further comprises: Based on the dynamic production data, the number of flow channels in each inter-well group is verified using the Fourier transform method.

3. The method according to claim 2, characterized in that Extracting a water content variation curve over time from the dynamic production data, and performing Fourier transform processing on the current water content variation curve to obtain a corresponding frequency spectrum; According to the water cut spectrum diagram, the peak number of the water cut spectrum diagram is counted, and the current number of flow channels is verified by combining the current peak number statistical results and the connectivity analysis information of each well group.

4. The method according to any one of claims 1 to 3, characterized in that The step of determining the number of flow paths of the well groups with a connectable relationship in the current reservoir unit according to the tracer test data of the injection and production well group includes: Determine the tracer production curve corresponding to each pair of well groups according to the tracer test data of the injection and production well groups; The number of flow channels in each pair of well groups is determined according to the number of peaks of the tracer production curve.

5. The method according to any one of claims 1 to 3, characterized in that: Calculate the corresponding water splitting rate according to the water injection volume corresponding to the current water injection time and the water splitting volume; According to the water split ratio, combined with the water injection speed and the breakthrough time of the injected water, the flow channel volume of the current unit is obtained.

6. The method according to claim 5, characterized in that Calculate the normal liquid production volume corresponding to the first production time before water injection; According to the normal liquid production volume, combined with the liquid production volume of the entire production stage, the unit pressure drop liquid production volume before water injection, and the production pressure change value at the first production time after water injection, the stage liquid production volume of each pressure increase section and each pressure drop section after water injection is calculated; The liquid extraction volumes in each of the stages are integrated to generate the water distribution volume of the current unit.

7. A system for calculating the amount of flow regulating channel plugging agent used in fracture-cavity oil reservoirs, comprising: A data collection module configured to collect tracer test data and dynamic production data of the injection and production well group of the reservoir unit to be studied; An inter-well flow channel number generation module is configured to determine the number of flow channels of the inter-well group with a connectable relationship in the current reservoir unit according to the tracer test data of the injection and production well group; A flow channel volume generation module is configured to perform an injection water effect analysis on the current unit based on the dynamic production data and adopt reservoir engineering theory, calculate the water distribution volume of the unit after water injection, and further obtain the corresponding flow channel volume; The plugging agent dosage generation module is configured to calculate the plugging agent dosage in the specified flow adjustment direction according to the flow channel volume and the number of flow channels in each inter-well group, using the ratio of the number of flow channels to be adjusted in the specified flow adjustment direction to the number of all flow channels related to the current flow adjustment direction. The plugging agent dosage generation module is further configured as follows: Determine the target well under the current flow adjustment direction and the first type of well group that can form a connectable relationship with the target well, and calculate the sum of the number of flow channels of all the first type of well groups to obtain the total number of flow channels of the target well; Referring to the connectivity analysis information of each well group, the number of actual connected flow paths of each pair of first-type well groups is determined, and the actual number of connected flow paths is added to obtain the number of well group connection directions; The number of flow channels that need to be regulated in the current flow regulation direction is determined. Based on this, the amount of flow regulation channel plugging agent in the current flow regulation direction is calculated in combination with the total number of flow channels of the target well, the number of connecting directions of the well group and the volume of the flow channels. The amount of plugging agent in the specified flow regulation direction is calculated using the following expression: Among them, V d It represents the amount of flow regulating channel plugging agent used in the current flow regulating direction, M represents the total number of flow channels in the target well, F represents the number of flow channels to be regulated in the current flow regulating direction, N represents the number of well group connection directions, and V represents the volume of the flow channel.

8. The system according to claim 7, characterized in that The system further comprises: The inter-well flow channel number verification module is configured to verify the number of flow channels of each inter-well group using the Fourier transform method according to the dynamic production data.

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