Method and apparatus for constructing fluid recognition model, fluid recognition method and device

Abstract

The present invention discloses a method and device for constructing a fluid identification model, a fluid identification method and equipment. For a sample fractured reservoir corresponding to different types of original fluids, by obtaining a first resistivity at a first position and a second resistivity at a second position in the sample fractured reservoir, wherein the original fluid in the sample fractured reservoir at the first position is completely displaced, and at the second position, the original fluid remains in the sample fractured reservoir, calculating the log-LLD ratio of the sample fractured reservoir based on the first resistivity and the second resistivity, and then constructing an acoustic travel time-log-LLD ratio model of the sample fractured reservoir based on the acoustic travel time and the log-LLD ratio of the sample fractured reservoir, so as to construct a fluid identification model based on the acoustic travel time-log-LLD ratio models respectively corresponding to different types of original fluids. This method is easy to execute, has clear and easily obtainable parameters, a wide applicable range and strong applicability.

Description

Technical Field

[0001] The present invention relates to the technical field of exploration, and in particular, to a method and device for constructing a fluid identification model, a fluid identification method, and equipment. Background Art

[0002] Fractures in tight reservoirs are important seepage channels and storage spaces for oil and gas. Due to the combined influence of multiple factors, fluid identification in fractured reservoirs has always been a difficult problem in logging evaluation.

[0003] In the prior art, the identification of fluids in fractured reservoirs is mainly based on pre-stack seismic attributes for prediction. By processing pre-stack gathers, seismic dynamic parameters at various azimuth angles and shear-wave impedance and compressional-wave impedance under isotropy are obtained, and a fracture fluid factor is calculated to obtain the detection result of fracture fluids; alternatively, by solving the invented frequency-dependent azimuth AVO formula, the compressional-wave anisotropic dispersion term is obtained to identify the fluid type in the fractures. In terms of logging identification, the prior art proposes to use fuzzy clustering analysis for indirect identification, or to use three methods for identifying fluid types, namely nuclear magnetic resonance logging method, conventional logging method, and production fluid profile method, to calculate the fluid type identification parameter FTI to identify fluids. The conventional logging method mainly believes that different fluid types are closely related to the level of resistivity ratio, the amount of clay content, and the size of porosity, etc. The fluid identification methods in the prior art need to consider the influence of multiple factors and are not simple enough. In order to improve the convenience of fluid identification, the present application provides a method for constructing a fluid identification model and a fluid identification method to more conveniently identify fluids. Summary of the Invention

[0004] The technical problem to be solved by the present invention is that the fluid identification methods in the prior art need to consider the influence of multiple factors and are not simple enough. In order to improve the convenience of fluid identification, the present application provides a method and device for constructing a fluid identification model, a fluid identification method, a storage medium, and equipment to provide a fluid identification model construction method with clear and easy-to-obtain parameters, wide application range, and strong applicability, and to more conveniently identify fluids based on the fluid identification model.

[0005] To solve the above technical problem, a first aspect of the present invention provides a method for constructing a fluid identification model. At a first position, the original fluid in the sample fractured reservoir is completely displaced, and at a second position, the original fluid remains in the sample fractured reservoir. The method for constructing the fluid identification model includes:

[0006] For the sample fractured reservoirs corresponding to different types of the original fluids, the following steps are respectively executed:

[0007] Obtain the first resistivity at the first position and the second resistivity at the second position in the sample fractured reservoir;

[0008] Calculate the log dual laterolog ratio of the sample fractured reservoir based on the first resistivity and the second resistivity;

[0009] Based on the acoustic travel time and the log dual laterolog ratio of the sample fractured reservoir, construct an acoustic travel time - log dual laterolog ratio model of the sample fractured reservoir, and construct the fluid identification model based on the acoustic travel time - log dual laterolog ratio models corresponding to different types of the original fluids respectively.

[0010] In some embodiments, based on the first resistivity and the second resistivity, use the following expression to calculate the log dual laterolog ratio of the sample fractured reservoir:

[0011] where R s represents the first resistivity, R d represents the second resistivity, and lgRds represents the log dual laterolog ratio.

[0012] In some embodiments, the types of the original fluids include at least two of oil and gas, water, gas, and gas - water mixture.

[0013] In some embodiments, the fracture occurrence of the sample fractured reservoir includes low - angle fractures, diagonal fractures, or high - angle fractures.

[0014] In the second aspect of the present invention, a fluid identification method is provided, which uses the fluid identification model constructed by the fluid identification model construction method as described above to identify fluids, including:

[0015] Obtain the first resistivity at the first position and the second resistivity at the second position in the target fractured reservoir, wherein at the first position, the fluid in the target fractured reservoir is completely displaced, and at the second position, the fluid remains in the target fractured reservoir;

[0016] Calculate the log dual laterolog ratio in the target fractured reservoir based on the first resistivity and the second resistivity;

[0017] Based on the acoustic travel time and the log dual laterolog ratio of the target fractured reservoir, use the fluid identification model to identify the fluid in the target fractured reservoir.

[0018] In some embodiments, based on the first resistivity and the second resistivity, use the following expression to calculate the log dual laterolog ratio of the target fractured reservoir:

[0019] where Rs represents the first resistivity, R d represents the second resistivity, and lgRds represents the log dual laterolog ratio.

[0020] In some embodiments, the fluid identification method further includes: identifying the target fractured reservoir by using the acoustic travel time and resistivity contrast method.

[0021] In a third aspect of the present invention, there is provided a device for constructing a fluid identification model, which includes:

[0022] An acquisition module, which is used to acquire the first resistivity at a first position and the second resistivity at a second position in a sample fractured reservoir corresponding to different types of original fluids. Wherein, at the first position, the original fluid in the sample fractured reservoir is completely displaced, and at the second position, the original fluid remains in the sample fractured reservoir;

[0023] A calculation module, which is used to calculate the log dual laterolog ratio of the sample fracture based on the first resistivity and the second resistivity;

[0024] A construction module, which is used to construct an acoustic travel time - log dual laterolog ratio model of the sample fractured reservoir based on the acoustic travel time and the log dual laterolog ratio of the sample fractured reservoir, so as to construct the fluid identification model based on the acoustic travel time - log dual laterolog ratio models respectively corresponding to different types of the original fluids.

[0025] In a fourth aspect of the present invention, there is provided a storage medium, in which a calculation program is stored, and when the computer program is executed by a processor, it can implement the fluid identification model construction method or the fluid identification method as described above.

[0026] In a fifth aspect of the present invention, there is provided a device, which includes: a memory and a processor, and a computer program is stored in the memory, and when the computer program is executed by the processor, it can implement the fluid identification model construction method or the fluid identification method as described above.

[0027] Compared with the prior art, one or more of the above - mentioned embodiments may have the following advantages or beneficial effects:

[0028] Applying the fluid identification model construction method provided by the present invention, for the sample fractured reservoirs corresponding to different types of original fluids, by obtaining the first resistivity at the first position and the second resistivity at the second position in the sample fractured reservoir, wherein the original fluid in the sample fractured reservoir at the first position is completely displaced, and at the second position, the original fluid remains in the sample fractured reservoir, calculating the log dual laterolog ratio of the sample fractured reservoir based on the first resistivity and the second resistivity, and then constructing the acoustic travel time - log dual laterolog ratio model of the sample fractured reservoir based on the acoustic travel time and the log dual laterolog ratio of the sample fractured reservoir, so as to construct a fluid identification model based on the acoustic travel time - log dual laterolog ratio models respectively corresponding to different types of original fluids. This method is easy to execute, the parameters are clear and easy to obtain, and it has a wide range of applications. It can be applied to complex reservoirs such as tight sandstone, volcanic rock, and carbonate. In addition, this method also considers the influence of fracture occurrence and has strong applicability. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] The scope of the present disclosure can be better understood by reading the following detailed description of exemplary embodiments in conjunction with the accompanying drawings. The accompanying drawings included are:

[0030] Figure 1 FIG. 1 shows a schematic flow chart of a fluid identification model construction method provided in Embodiment 1 of the present invention;

[0031] Figure 2 FIG. 2 shows a schematic diagram of a fluid identification model provided in an embodiment of the present invention;

[0032] Figure 3 FIG. 3 shows a schematic flow chart of a fluid identification method provided in Embodiment 2 of the present invention;

[0033] Figure 4 FIG. 4 shows a schematic flow chart of a fluid identification method provided in Embodiment 3 of the present invention;

[0034] Figure 5 FIG. 5 shows a schematic diagram of a fluid identification model provided in a specific example of the present invention;

[0035] Figure 6 FIG. 6 shows a schematic diagram of the logging response characteristics of Well M;

[0036] Figure 7 FIG. 7 shows a schematic diagram of identifying the fluid in Well M based on the fluid identification model provided in a specific example of the present invention;

[0037] Figure 8 FIG. 8 shows a fluid identification model construction device provided in Embodiment 4 of the present invention;

[0038] Figure 9 FIG. 9 shows a schematic diagram of a device provided in an embodiment of the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0039] To make the objectives, technical solutions and advantages of the present invention clearer, the following will, in conjunction with the accompanying drawings and embodiments, elaborate on the implementation method of the present invention in detail, so as to fully understand how the present invention applies technical means to solve technical problems and achieve the implementation process of technical effects and implement accordingly.

[0040] Fractures in tight reservoirs are important seepage channels and storage spaces for oil and gas. However, due to the combined influence of multiple factors, fluid identification in fractured reservoirs has always been a difficult problem in logging evaluation.

[0041] In the prior art, the identification of fluids in fractured reservoirs is mainly based on pre-stack seismic attributes for prediction. By processing the pre-stack gathers, seismic dynamic parameters in each azimuth angle and shear wave impedance and compressional wave impedance under isotropy are obtained, the fracture fluid factor is calculated, and the detection result of fracture fluids is obtained; alternatively, by solving the invented frequency-dependent azimuthal AVO formula, the compressional wave anisotropic dispersion term is obtained to identify the fluid type in the fracture. In terms of logging identification, the prior art proposes to use fuzzy clustering analysis for indirect identification, or to use three methods for identifying fluid types, namely nuclear magnetic resonance logging method, conventional logging method and production fluid profile method, to calculate the fluid type identification parameter FTI to identify fluids. Among them, the conventional logging method mainly believes that different fluid types are closely related to the level of resistivity ratio, the amount of clay content, the size of porosity, etc. The fluid identification methods in the prior art need to consider the influence of multiple factors and are not simple enough. To improve the convenience of fluid identification, the present application provides a method for constructing a fluid identification model and a fluid identification method to more conveniently identify fluids.

[0042] In view of this, the present invention provides a method for constructing a fluid identification model. For a sample fractured reservoir corresponding to different types of original fluids, by obtaining the first resistivity at a first position and the second resistivity at a second position in the sample fractured reservoir, wherein the original fluid in the sample fractured reservoir at the first position is completely displaced, and at the second position, the original fluid remains in the sample fractured reservoir, calculate the logarithm of the dual laterolog ratio of the sample fractured reservoir based on the first resistivity and the second resistivity, and then construct a sonic travel time-logarithm of dual laterolog ratio model of the sample fractured reservoir based on the sonic travel time and the logarithm of the dual laterolog ratio of the sample fractured reservoir, so as to construct a fluid identification model based on the sonic travel time-logarithm of dual laterolog ratio models respectively corresponding to different types of original fluids. This method is simple to execute, the parameters are clear and easy to obtain, has a wide range of applications, and can be applied to complex reservoirs such as tight sandstone, volcanic rock and carbonate. In addition, this method also considers the influence of fracture occurrence and has strong applicability.

[0043] Before describing the embodiments of the present invention, the theory underlying this solution is first described. During the drilling process, since the mud pressure in the wellbore is higher than the formation pressure, the mud invades the formation along the fractures, displacing the original fluid in the fractures near the wellbore. There is less residual original fluid near the wellbore, while it is difficult to completely displace the original fluid in the deep part of the fractures, and there is still a large amount of residual original fluid.

[0044] For dual laterolog resistivity logging, the parallel conduction of the fluid in the fractures and the formation can cause a decrease in resistivity. Among them, due to the shallow detection depth of the shallow laterolog, it is mainly the parallel conduction of the fluid in the fractures in the near-wellbore zone and the formation, and the resistivity decreases significantly. For the deep laterolog with a larger detection depth, it can detect deep fractures and can reflect the conductivity of the original fluid in the fractures to a certain extent. When there is a large amount of oil and gas residue in it, the resistivity of the fluid in the fractures is relatively high, and the decrease in the deep laterolog resistivity caused by parallel connection is relatively small, resulting in a positive difference in the shallow and deep dual laterolog resistivities. When the original fluid is water, the dual laterolog is weakly affected by the fluid difference and shows no difference. On the other hand, the fracture attitude also affects the dual laterolog difference. For low-angle fractures, the dual laterolog conduction forms are the same, and under the same fluid conditions, their responses are almost indistinguishable. For high-angle fractures, since the detection range of the shallow laterolog is smaller than that of the deep laterolog, the proportion of the volume of fractures in the detection range is relatively large, and affected by this, the resistivity decrease is more obvious, which also leads to a positive difference in the shallow and deep dual laterologs.

[0045] Under the dual influence of these two factors, there are differences in the dual laterolog responses of different types of fractures. For high-angle fractures containing gas, both factors lead to a positive dual laterolog difference, and the superimposed positive dual laterolog difference is more obvious. For low-angle fractures containing water, the dual laterologs are completely indistinguishable, and for low-angle fractures containing gas and high-angle fractures containing water, they show a weak dual laterolog difference.

[0046] For acoustic travel time logging, there are also differences in the responses of different fracture attitudes and the fluids they contain. Low-angle fractures and oblique fractures intercept the propagation direction of the shear wave, and the fracture surface has strong refraction and scattering of the acoustic wave, resulting in obvious attenuation of the acoustic wave amplitude, causing the arrival of the first wave detected by the probe to be delayed or even cycle skipping, and then increasing the acoustic travel time measured in the fracture-developed sections. For high-angle fractures, the propagation direction of the shear wave is consistent with the fracture strike, and the fracture has a weak influence on the shear wave, and the acoustic travel time is not greatly affected. At the same time, the propagation speed of the acoustic wave in the fluid in the fractures is also significantly lower than that of the formation. Especially when the fluid contains gas, even a very low gas saturation will also cause a significant increase in the acoustic travel time. Under the dual influence of these two factors, there are also differences in the acoustic travel time responses of different types of fractures. For low-angle fractures and oblique fractures containing gas, both factors lead to an increase in the acoustic travel time, and the superimposed amplification causes a significant increase in the acoustic travel time. For high-angle fractures containing water, the acoustic travel time is not affected at all, and for high-angle fractures containing gas and low-angle fractures containing water, they show a weak increase in the acoustic travel time.

[0047] The present invention makes full use of the response mechanisms of dual laterolog resistivity logging and acoustic travel time logging. By constructing cross plots of the dual laterolog differences and acoustic travel times corresponding to various fluid types, fluid identification is further realized. It should be noted that the dual laterolog difference can be represented by the logarithm of the dual laterolog ratio.

[0048] Example 1

[0049] See Figure 1 as shown Figure 1 which shows a schematic flow chart of a method for constructing a fluid identification model provided in Embodiment 1 of the present invention.

[0050] In some embodiments, when constructing a fluid identification model, multiple sample fractured reservoirs can be selected, and the multiple sample fractured reservoirs can have the same fracture occurrence; in other embodiments, when constructing a fluid identification model, multiple sample fractured reservoirs can also be selected, and the multiple sample fractured reservoirs can have different fracture occurrences.

[0051] At a first position, the original fluid in the sample fractured reservoir is completely displaced, and at a second position, the original fluid remains in the sample fractured reservoir. The method for constructing a fluid identification model can include: for the sample fractured reservoirs corresponding to different types of original fluids, respectively perform the following steps:

[0052] Step S101: Obtain a first resistivity at the first position and a second resistivity at the second position in the sample fractured reservoir.

[0053] Step S102: Calculate the logarithm of the dual laterolog ratio of the sample fractured reservoir based on the first resistivity and the second resistivity.

[0054] Step S103: Based on the acoustic travel time and the logarithm of the dual laterolog ratio of the sample fractured reservoir, construct an acoustic travel time - logarithm of dual laterolog ratio model of the sample fractured reservoir, and construct a fluid identification model based on the acoustic travel time - logarithm of dual laterolog ratio models respectively corresponding to different types of original fluids.

[0055] In step S101, conventional resistivity measurement methods in the art can be used to measure the sample fractured reservoir. Among them, the first resistivity corresponds to the resistivity of the displaced fluid in the fractured reservoir at the first position, and the second resistivity corresponds to the resistivity of the original fluid in the fractured reservoir at the second position.

[0056] The types of the original fluid can include at least two of oil and gas, water, gas, and gas - water mixture, and the fracture occurrences of the fractured reservoir can include low - angle fractures, inclined fractures, or high - angle fractures.

[0057] In the embodiment of the present invention, step S102 can be specifically:

[0058] Based on the first resistivity and the second resistivity, the logarithmic dual laterolog ratio of the sample fractured reservoir is calculated using the following expression:

[0059]

[0060] where R s represents the first resistivity, R d represents the second resistivity, and lgRds represents the logarithmic dual laterolog ratio.

[0061] Step S103 can be specifically as follows: The acoustic travel time is obtained in advance. Based on the acoustic travel time and the logarithmic dual laterolog ratio of the sample fractured reservoir, an acoustic travel time - logarithmic dual laterolog ratio model of the sample fractured reservoir is constructed. The acoustic travel time - logarithmic dual laterolog ratio model can also be shown in the form of an acoustic travel time - logarithmic dual laterolog ratio distribution diagram. Among them, the acoustic travel time can be used as the ordinate of the acoustic travel time - logarithmic dual laterolog ratio distribution diagram, and the logarithmic dual laterolog ratio can be used as the abscissa of the acoustic travel time - logarithmic dual laterolog ratio distribution diagram.

[0062] The acoustic travel time - logarithmic dual laterolog ratio distribution diagram corresponds one - to - one with the type of the original fluid. By fusing the acoustic travel time - logarithmic dual laterolog ratio distribution diagrams corresponding to different types of the obtained original fluids, a fluid identification model is constructed.

[0063] In some other embodiments, when multiple sample fractured reservoirs with different fracture occurrences are selected to construct the fluid identification model, for the same type of original fluid, the acoustic travel time - logarithmic dual laterolog ratio distribution diagrams corresponding to different fracture occurrences are obtained. Finally, the acoustic travel time - logarithmic dual laterolog ratio distribution diagrams corresponding to different fracture occurrences of each type of original fluid are fused to construct a fluid identification model.

[0064] As an example, referring to Figure 2 shown, Figure 2 shows a schematic diagram of the fluid identification model provided by the embodiment of the present invention. When the fluid is water, the acoustic travel time of the fractured water layer is low and the dual laterolog difference is small; when the fluid is gas, the acoustic travel time of the fractured gas layer is large and the dual laterolog difference is large; when the fluid is a gas - water mixture, the relevant data of the fractured gas - water layer are distributed between the relevant data distributions of the fractured water layer and the fractured gas layer. At the same time, the influence of the fracture occurrence is also considered in the distribution diagram. The low - angle fractures are mainly concentrated on one side of the distribution diagram close to the vertical axis, corresponding to a relatively high acoustic travel time boundary between the fractured gas layer and the fractured water layer, while the dual laterolog difference is relatively small; the high - angle fractures are concentrated on the side of the distribution diagram far from the vertical axis, corresponding to a relatively low acoustic travel time boundary between the fractured gas layer and the fractured water layer, while the dual laterolog difference is relatively large. And for the fractured gas layer and the fractured gas - water layer, due to the gas content causing a positive dual laterolog difference, the logarithmic dual laterolog ratio should be greater than 1.0.

[0065] The above is a method for constructing a fluid identification model provided by an embodiment of the present invention. For sample fractured reservoirs corresponding to different types of original fluids, by obtaining the first resistivity at the first position and the second resistivity at the second position in the sample fractured reservoir, where the original fluid in the sample fractured reservoir at the first position is completely displaced, and at the second position, the original fluid remains in the sample fractured reservoir, calculate the log-ratio of the dual laterolog of the sample fractured reservoir based on the first resistivity and the second resistivity, and then construct the acoustic travel time-log-ratio of dual laterolog model of the sample fractured reservoir based on the acoustic travel time and the log-ratio of the dual laterolog of the sample fractured reservoir, so as to construct a fluid identification model based on the acoustic travel time-log-ratio of dual laterolog models respectively corresponding to different types of original fluids. This method is simple to execute, with clear and easy-to-obtain parameters, wide applicability, and can be applied to complex reservoirs such as tight sandstone, volcanic rock, and carbonate. In addition, this method also considers the influence of fracture occurrence and has strong applicability.

[0066] Correspondingly, the present invention also provides a fluid identification method based on the fluid identification model. For specific descriptions, please refer to the following embodiments.

[0067] Example 2

[0068] See Figure 3 as shown Figure 3 which shows a schematic flow chart of a fluid identification method provided by Embodiment 2 of the present invention.

[0069] The fluid identification method provided by the embodiment of the present invention uses the fluid identification model constructed in the above Embodiment 1 for fluid identification, including:

[0070] Step S201: Obtain the first resistivity at the first position and the second resistivity at the second position in the target fractured reservoir, where at the first position, the fluid in the target fractured reservoir is completely displaced, and at the second position, the fluid remains in the target fractured reservoir.

[0071] Step S202: Calculate the log-ratio of the dual laterolog in the target fractured reservoir based on the first resistivity and the second resistivity.

[0072] Step S203: Identify the fluid in the target fractured reservoir using the fluid identification model based on the acoustic travel time and the log-ratio of the dual laterolog of the target fractured reservoir.

[0073] In the embodiment of the present invention, Step S201 can be specifically: measuring the target fractured reservoir using a conventional resistivity measurement method in the art, where the first resistivity corresponds to the resistivity of the displaced fluid in the fractured reservoir at the first position, and the second resistivity corresponds to the resistivity of the original fluid in the fractured reservoir at the second position.

[0074] In the embodiments of the present invention, step S202 may specifically be as follows:

[0075] Based on the first resistivity and the second resistivity, calculate the log dual laterolog ratio of the sample fractured reservoir by using the following expression:

[0076]

[0077] where R s represents the first resistivity, R d represents the second resistivity, and lgRds represents the log dual laterolog ratio.

[0078] Step S203 may specifically be as follows: First, obtain the acoustic travel time of the target fractured reservoir in advance, and input the acoustic travel time and the log dual laterolog ratio of the target fractured reservoir into a pre-constructed fluid identification model. Then, based on the corresponding relationship between the acoustic travel time, the log dual laterolog ratio, and the fluid type, identify the fluid in the target fractured reservoir.

[0079] It should be noted that in some embodiments, the pre-constructed fluid identification model may be as follows: For multiple selected sample fractured reservoirs, the multiple sample fractured reservoirs may have the same fracture occurrence. For the sample fractured reservoirs corresponding to different types of original fluids, based on the acoustic travel time and the log dual laterolog ratio of the sample fractured reservoirs, construct the acoustic travel time - log dual laterolog ratio distribution map of the sample fractured reservoirs. Among them, the acoustic travel time can be used as the ordinate of the acoustic travel time - log dual laterolog ratio distribution map, and the log dual laterolog ratio can be used as the abscissa of the acoustic travel time - log dual laterolog ratio distribution map. The acoustic travel time - log dual laterolog ratio distribution map corresponds one-to-one with the type of the original fluid. By fusing the acoustic travel time - log dual laterolog ratio distribution maps corresponding to different types of original fluids obtained, the fluid identification model is constructed.

[0080] Correspondingly, when identifying the fluid in the target fractured reservoir based on the acoustic travel time and the log dual laterolog ratio of the target fractured reservoir by using the fluid identification model, the fracture occurrence of the target fractured reservoir can be identified in advance, and the fluid identification can be performed based on the fluid identification model corresponding to the corresponding fracture occurrence.

[0081] In other embodiments, the pre-constructed fluid identification model may be as follows: Select multiple sample fractured reservoirs to construct the fluid identification model. The multiple sample fractured reservoirs have different fracture occurrences. For the same type of original fluid, obtain the acoustic travel time - log dual laterolog ratio distribution maps corresponding to different fracture occurrences, and finally fuse the acoustic travel time - log dual laterolog ratio distribution maps corresponding to different fracture occurrences of each type of original fluid to construct the fluid identification model.

[0082] Correspondingly, when identifying the fluid in the target fractured reservoir by using the fluid identification model based on the acoustic travel time difference and the logarithm of the dual laterolog ratio of the target fractured reservoir, the fracture occurrence of the target fractured reservoir does not need to be considered, and the acoustic travel time difference and the logarithm of the dual laterolog ratio of the target fractured reservoir can be directly input into the fluid identification model to identify the fluid in the target fractured reservoir. This method is convenient to execute, does not need to consider the influence of various factors, and has a wider application range and stronger adaptability.

[0083] The above is a fluid identification method provided by an embodiment of the present invention, which uses the fluid identification model described in Embodiment 1 above to identify the fluid. By obtaining the first resistivity at the first position and the second resistivity at the second position in the target fractured reservoir, where the fluid in the target fractured reservoir is completely displaced at the first position and there is still fluid in the target fractured reservoir at the second position, calculating the logarithm of the dual laterolog ratio in the target fractured reservoir based on the first resistivity and the second resistivity, and finally identifying the fluid in the target fractured reservoir by using the fluid identification model based on the acoustic travel time difference and the logarithm of the dual laterolog ratio of the target fractured reservoir. This method has clear parameters and is easy to obtain, does not need to consider the influence of various factors, has a wider application range and stronger adaptability, and is beneficial to more convenient identification of fluids.

[0084] Before fluid identification, the target fractured reservoir can be pre-identified. For specific details, please refer to the description in Embodiment 3 below.

[0085] Example 3

[0086] See Figure 4 As shown in Figure 4 Fig. shows a schematic flow chart of a fluid identification method provided by Embodiment 3 of the present invention.

[0087] The fluid identification method provided by the embodiment of the present invention uses the fluid identification model constructed in Embodiment 1 above to identify the fluid, including:

[0088] Step S301: Identify the target fractured reservoir by using the acoustic travel time difference and resistivity comparison method.

[0089] Step S302: Obtain the first resistivity at the first position and the second resistivity at the second position in the target fractured reservoir, where the fluid in the target fractured reservoir is completely displaced at the first position and there is still fluid in the target fractured reservoir at the second position.

[0090] Step S303: Calculate the logarithm of the dual laterolog ratio in the target fractured reservoir based on the first resistivity and the second resistivity.

[0091] Step S304: Identify the fluid in the target fractured reservoir by using the fluid identification model based on the acoustic travel time difference and the logarithm of the dual laterolog ratio of the target fractured reservoir.

[0092] In an embodiment of the present invention, step S301 may specifically be to detect the acoustic travel time and resistivity of the target area. When the acoustic travel time is not high and the measured resistivity curve shows a spiky low-resistivity feature, and there is no obvious shale spike with high natural gamma, cracks in the target area can be identified, and thus the cracks identified in the target area can be used as the target fracture reservoir.

[0093] The method for identifying the target fracture reservoir based on the acoustic travel time and resistivity can further apply the measured acoustic travel time during the identification process to the identification of fluids, realizing the multiple utilization of measurement data, which is further beneficial to improving the convenience of fluid identification.

[0094] In an embodiment of the present invention, step S302 may specifically be to measure the target fracture reservoir using a conventional resistivity measurement method in the art. Among them, the first resistivity corresponds to the resistivity of the displacing fluid in the fracture reservoir at the first position, and the second resistivity corresponds to the resistivity of the original fluid in the fracture reservoir at the second position.

[0095] In an embodiment of the present invention, step S303 may specifically be:

[0096] Based on the first resistivity and the second resistivity, use the following expression to calculate the log dual laterolog ratio of the sample fracture reservoir:

[0097]

[0098] Where R s represents the first resistivity, R d represents the second resistivity, and lgRds represents the log dual laterolog ratio.

[0099] Step S304 may specifically be to pre-obtain the acoustic travel time of the target fracture reservoir, and input the acoustic travel time and the log dual laterolog ratio of the target fracture reservoir into a pre-constructed fluid identification model, so as to identify the fluid in the target fracture reservoir according to the corresponding relationship between the acoustic travel time and the log dual laterolog ratio and the fluid type.

[0100] It should be noted that in some embodiments, the pre-constructed fluid identification model can be as follows: for multiple selected sample fractured reservoirs, the multiple sample fractured reservoirs can have the same fracture occurrence. For the sample fractured reservoirs corresponding to different types of original fluids, based on the acoustic travel time difference and the logarithm of the dual laterolog ratio of the sample fractured reservoirs, a distribution map of the acoustic travel time difference - logarithm of the dual laterolog ratio of the sample fractured reservoirs is constructed. Among them, the acoustic travel time difference can be used as the ordinate of the distribution map of the acoustic travel time difference - logarithm of the dual laterolog ratio, and the logarithm of the dual laterolog ratio can be used as the abscissa of the distribution map of the acoustic travel time difference - logarithm of the dual laterolog ratio. The distribution map of the acoustic travel time difference - logarithm of the dual laterolog ratio corresponds one-to-one with the type of the original fluid. By fusing the distribution maps of the acoustic travel time difference - logarithm of the dual laterolog ratio corresponding to different types of the original fluids obtained, a fluid identification model is constructed.

[0101] Correspondingly, when identifying the fluid in the target fractured reservoir by using the fluid identification model based on the acoustic travel time difference and the logarithm of the dual laterolog ratio of the target fractured reservoir, the fracture occurrence of the target fractured reservoir can be pre-identified, and fluid identification can be performed based on the fluid identification model corresponding to the corresponding fracture occurrence.

[0102] In some other embodiments, the pre-constructed fluid identification model can be as follows: when constructing the fluid identification model, multiple sample fractured reservoirs are selected. The multiple sample fractured reservoirs have different fracture occurrences. For the same type of original fluid, the distribution maps of the acoustic travel time difference - logarithm of the dual laterolog ratio corresponding to different fracture occurrences are obtained. Finally, the distribution maps of the acoustic travel time difference - logarithm of the dual laterolog ratio corresponding to different fracture occurrences of each type of the original fluid are fused to construct a fluid identification model.

[0103] Correspondingly, when identifying the fluid in the target fractured reservoir by using the fluid identification model based on the acoustic travel time difference and the logarithm of the dual laterolog ratio of the target fractured reservoir, the fracture occurrence of the target fractured reservoir does not need to be considered, and the acoustic travel time difference and the logarithm of the dual laterolog ratio of the target fractured reservoir can be directly input into the fluid identification model to perform fluid identification of the target fractured reservoir. This method is convenient to execute, does not need to consider the influence of various factors, and has a wider application range and stronger adaptability.

[0104] The above is a fluid identification method provided by an embodiment of the present invention. It uses the fluid identification model constructed by the fluid identification model construction method described in Embodiment 1 above for fluid identification. First, it identifies the target fractured reservoir based on the method of acoustic travel time difference and resistivity. By obtaining the first resistivity at the first position and the second resistivity at the second position in the target fractured reservoir, where at the first position, the fluid in the target fractured reservoir is completely displaced, and at the second position, there is still fluid in the target fractured reservoir. Calculate the log dual laterolog ratio in the target fractured reservoir based on the first resistivity and the second resistivity. Finally, based on the acoustic travel time difference and the log dual laterolog ratio of the target fractured reservoir, use the fluid identification model to identify the fluid in the target fractured reservoir. This method has clear parameters and is easy to obtain, without considering the influence of various factors, has a wider application range and stronger adaptability, which is conducive to more convenient fluid identification. In addition, the acoustic travel time difference measured during the process of identifying the target fractured reservoir can be further applied to fluid identification, realizing the reuse of measurement data, which is further conducive to improving the convenience of fluid identification.

[0105] Specific Example

[0106] The target interval develops thick sand bodies with fractures developed. By selecting the fractures in this formation as the test section, extracting the log dual laterolog ratio and acoustic travel time difference of the fracture points in the test section, a fluid identification model is constructed, as Figure 5 shown Figure 5 shows the schematic diagram of the fluid identification model provided by a specific example of the present invention. The abscissa is the log dual laterolog ratio, and the ordinate is the acoustic travel time difference. It can be seen that the different fluid fractured reservoir zones are obvious. In addition, according to the constructed fluid identification model, the fluid identification standard table shown in Table 1 can be obtained:

[0107]

[0108] Among them, the corresponding fluid in the fractured gas layer is gas, the corresponding fluid in the fractured gas-water layer is a gas-water mixture, and the corresponding fluid in the fractured water layer is water.

[0109] Well M is a dedicated layer well in the target interval. Fracture testing is carried out on the tight sandstone in the target interval, with a daily gas production of 1.0052 million cubic meters, and it is evaluated as a gas layer, that is, the fluid is gas. According to the previous data, it is determined that fractures develop at X25 - XX28.5m and XX44 - XX53m in this well, corresponding to Figure 6 the marked fracture sections Figure 6 shows the schematic diagram of the well logging response characteristics of Well M. At the same time, project the data of the typical layer points m1 - m4 of this fracture section onto the fluid identification model, as Figure 7 shown Figure 7The figure shows a schematic diagram of identifying the fluid in Well M based on the fluid identification model provided by a specific example of the present invention, where the black triangles represent the test point data corresponding to m1, m2, m3, or m4 in Well M. It can be seen that the test point data corresponding to m1, m2, m3, or m4 are all concentrated in the fractured gas reservoir area, and the identified fluid is also gas, which is consistent with the test results obtained by using the fracturing test, thereby verifying the effectiveness of the fluid identification model and the fluid identification method provided by the present invention.

[0110] On the other hand, the present invention also correspondingly provides a device for constructing a fluid identification model. For details, please refer to the description of Embodiment 4 below.

[0111] Example 4

[0112] See Figure 8 as shown Figure 8 The figure shows a device for constructing a fluid identification model provided in Embodiment 4 of the present invention, which includes:

[0113] A collection module 40, which is used to obtain the first resistivity at the first position and the second resistivity at the second position in the sample fractured reservoir corresponding to different types of original fluids. Wherein, at the first position, the original fluid in the sample fractured reservoir is completely displaced, and at the second position, the original fluid remains in the sample fractured reservoir;

[0114] A calculation module 41, which is used to calculate the logarithm of the dual laterolog ratio of the sample fracture based on the first resistivity and the second resistivity;

[0115] A construction module 42, which is used to construct an acoustic travel time - logarithm of the dual laterolog ratio model of the sample fractured reservoir based on the acoustic travel time and the logarithm of the dual laterolog ratio of the sample fractured reservoir, so as to construct a fluid identification model based on the acoustic travel time - logarithm of the dual laterolog ratio models corresponding to different types of original fluids.

[0116] Among them, the sample fractured reservoir can be measured by using conventional resistivity measurement methods in the art. The first resistivity corresponds to the resistivity of the displaced fluid in the fractured reservoir at the first position, and the second resistivity corresponds to the resistivity of the original fluid in the fractured reservoir at the second position.

[0117] The types of the original fluids can include at least two of oil and gas, water, gas, and gas - water mixture, and the fracture occurrence of the fractured reservoir can include low - angle fractures, diagonal fractures, or high - angle fractures.

[0118] In the embodiment of the present invention, the calculation module 41 can calculate the logarithm of the dual laterolog ratio of the sample fractured reservoir based on the first resistivity and the second resistivity by using the following expression:

[0119]

[0120] wherein R s represents the first resistivity, and R d represents the second resistivity, and lgRds represents the log dual laterolog ratio.

[0121] The building block 42 can construct a distribution map of acoustic travel time - log dual laterolog ratio of the sample fractured reservoir based on the acoustic travel time and the log dual laterolog ratio of the sample fractured reservoir. Among them, the acoustic travel time can be used as the ordinate of the distribution map of acoustic travel time - log dual laterolog ratio, and the log dual laterolog ratio can be used as the abscissa of the distribution map of acoustic travel time - log dual laterolog ratio.

[0122] The distribution map of acoustic travel time - log dual laterolog ratio corresponds one - to - one with the type of the original fluid. By fusing the distribution maps of acoustic travel time - log dual laterolog ratio corresponding to different types of original fluids obtained, a fluid identification model is constructed.

[0123] In some other embodiments, when multiple sample fractured reservoirs with different fracture occurrences are selected to construct the fluid identification model, for the same type of original fluid, distribution maps of acoustic travel time - log dual laterolog ratio corresponding to different fracture occurrences can be obtained, and finally, the distribution maps of acoustic travel time - log dual laterolog ratio corresponding to different fracture occurrences of each type of original fluid are fused to construct the fluid identification model.

[0124] As an example, refer to Figure 2 as shown Figure 2 which shows a schematic diagram of the fluid identification model provided by the embodiment of the present invention. When the fluid is water, the acoustic travel time of the fractured water layer is low and the dual laterolog difference is small; when the fluid is gas, the acoustic travel time of the fractured gas layer is large and the dual laterolog difference is large; when the fluid is a gas - water mixture, the relevant data of the fractured gas - water layer are distributed between the relevant data distributions of the fractured water layer and the fractured gas layer. At the same time, the influence of fracture occurrence is also considered in the distribution map. Low - angle fractures are mainly concentrated on one side of the distribution map close to the vertical axis, corresponding to a relatively high acoustic travel time boundary between the fractured gas layer and the fractured water layer, while the dual laterolog difference is relatively small; high - angle fractures are concentrated on the side of the distribution map far from the vertical axis, corresponding to a relatively low acoustic travel time boundary between the fractured gas layer and the fractured water layer, while the dual laterolog difference is relatively large. And for the fractured gas layer and the fractured gas - water layer, due to the gas - induced positive dual laterolog difference, the log dual laterolog ratio should be greater than 1.0.

[0125] The above is a device for constructing a fluid identification model provided by an embodiment of the present invention. For sample fractured reservoirs corresponding to different types of original fluids, the acquisition module 40 can obtain the first resistivity at the first position and the second resistivity at the second position in the sample fractured reservoirs corresponding to different types of original fluids; the calculation module 41 can calculate the logarithm of the dual laterolog ratio of the sample fractured reservoir based on the first resistivity and the second resistivity obtained by the acquisition module 40; and then the construction module 42 constructs an acoustic travel time - logarithm of dual laterolog ratio model of the sample fractured reservoir based on the acoustic travel time and the logarithm of the dual laterolog ratio of the sample fractured reservoir, so as to construct a fluid identification model based on the acoustic travel time - logarithm of dual laterolog ratio models corresponding to different types of original fluids respectively. This device is easy to operate, with clear and easy - to - obtain parameters, wide application range, and can be applied to complex reservoirs such as tight sandstone, volcanic rock, and carbonate. In addition, this device also considers the influence of fracture attitude and has strong applicability.

[0126] Example 5

[0127] On the other hand, the present invention also provides a storage medium in which a computer program is stored. When the computer program is executed by a processor, it can implement the fluid identification model construction method or the fluid identification method as described above.

[0128] In some embodiments, when the computer program stored in the storage medium is executed by a processor, it can implement the fluid identification model construction method as described above:

[0129] For sample fractured reservoirs corresponding to different types of original fluids, the following steps are respectively executed:

[0130] Obtain the first resistivity at the first position and the second resistivity at the second position in the sample fractured reservoir;

[0131] Calculate the logarithm of the dual laterolog ratio of the sample fractured reservoir based on the first resistivity and the second resistivity;

[0132] Construct an acoustic travel time - logarithm of dual laterolog ratio model of the sample fractured reservoir based on the acoustic travel time and the logarithm of the dual laterolog ratio of the sample fractured reservoir, so as to construct a fluid identification model based on the acoustic travel time - logarithm of dual laterolog ratio models corresponding to different types of original fluids respectively.

[0133] Among them, the sample fractured reservoir can be measured by using conventional resistivity measurement methods in the art. Among them, the first resistivity corresponds to the resistivity of the displacing fluid in the fractured reservoir at the first position, and the second resistivity corresponds to the resistivity of the original fluid in the fractured reservoir at the second position.

[0134] The types of the original fluid may include at least two of oil and gas, water, gas, and gas-water mixture, and the fracture occurrence of the fractured reservoir may include low-angle fractures, diagonal fractures, or high-angle fractures.

[0135] Based on the first resistivity and the second resistivity, the log dual laterolog ratio of the sample fractured reservoir is calculated using the following expression:

[0136]

[0137] where R s represents the first resistivity, R d represents the second resistivity, and lgRds represents the log dual laterolog ratio.

[0138] When the computer program stored in the storage medium is executed by the processor, the fluid identification model construction method is implemented. For the sample fractured reservoirs corresponding to different types of original fluids, by obtaining the first resistivity at the first position and the second resistivity at the second position in the sample fractured reservoir, where the original fluid in the sample fractured reservoir is completely displaced at the first position and the original fluid remains in the sample fractured reservoir at the second position, the log dual laterolog ratio of the sample fractured reservoir is calculated based on the first resistivity and the second resistivity, and then based on the acoustic travel time difference and the log dual laterolog ratio of the sample fractured reservoir, an acoustic travel time difference - log dual laterolog ratio model of the sample fractured reservoir is constructed, so as to construct a fluid identification model based on the acoustic travel time difference - log dual laterolog ratio models respectively corresponding to different types of original fluids. It can achieve the beneficial effects of simple execution, clear and easy-to-obtain parameters, wide application range, and strong applicability, and can be applied to complex reservoirs such as tight sandstone, volcanic rock, and carbonate.

[0139] In another embodiment, when the computer program stored in the storage medium is executed by the processor, the fluid identification method as described above can be implemented:

[0140] Obtain the first resistivity at the first position and the second resistivity at the second position in the target fractured reservoir, where the fluid in the target fractured reservoir is completely displaced at the first position and the fluid remains in the target fractured reservoir at the second position;

[0141] Calculate the log dual laterolog ratio in the target fractured reservoir based on the first resistivity and the second resistivity;

[0142] Identify the fluid in the target fractured reservoir using the fluid identification model based on the acoustic travel time difference and the log dual laterolog ratio of the target fractured reservoir.

[0143] Or,

[0144] Identify the target fractured reservoir using the acoustic travel time difference and resistivity comparison method;

[0145] Obtain the first resistivity at the first position and the second resistivity at the second position in the target fractured reservoir. Among them, at the first position, the fluid in the target fractured reservoir is completely displaced, and at the second position, there is still fluid in the target fractured reservoir;

[0146] Calculate the log-LLD ratio in the target fractured reservoir based on the first resistivity and the second resistivity;

[0147] Identify the fluid in the target fractured reservoir by using the fluid identification model based on the acoustic travel time difference and the log-LLD ratio of the target fractured reservoir.

[0148] Among them, the types of the original fluid can include at least two of oil and gas, water, gas, and gas-water mixture, and the fracture occurrence of the fractured reservoir can include low-angle fractures, inclined fractures, or high-angle fractures.

[0149] Based on the first resistivity and the second resistivity, calculate the log-LLD ratio of the sample fractured reservoir by using the following expression:

[0150]

[0151] Where R s represents the first resistivity, R d represents the second resistivity, and lgRds represents the log-LLD ratio.

[0152] When the computer program stored in the storage medium is executed by the processor, the fluid identification method described above is implemented. It uses the fluid identification model constructed in the first embodiment above for fluid identification. First, it identifies the target fractured reservoir based on the acoustic travel time difference and resistivity method. By obtaining the first resistivity at the first position and the second resistivity at the second position in the target fractured reservoir, among them, at the first position, the fluid in the target fractured reservoir is completely displaced, and at the second position, there is still fluid in the target fractured reservoir, calculate the log-LLD ratio in the target fractured reservoir based on the first resistivity and the second resistivity, and finally identify the fluid in the target fractured reservoir by using the fluid identification model based on the acoustic travel time difference and the log-LLD ratio of the target fractured reservoir. It can achieve the beneficial effects of clear and easy-to-obtain parameters, without considering the influence of various factors, wider application range, stronger adaptability, and being conducive to more convenient fluid identification. In addition, the acoustic travel time difference measured during the process of identifying the target fractured reservoir can be further applied to fluid identification, realizing the multiple use of measurement data, which is further conducive to improving the convenience of fluid identification.

[0153] The processes, functions, methods, and / or software described above can be recorded, stored, or fixed in one or more computer-readable storage media, which include program instructions that will be implemented by a computer to cause a processor to execute the program instructions. The storage media may also separately include program instructions, data files, data structures, etc., or include a combination thereof. The storage media or program instructions can be specifically designed and understood by those skilled in the computer software field, or the storage media or instructions may be well-known and available to those skilled in the computer software field. Examples of computer-readable media include: magnetic media, such as hard disks, floppy disks, and magnetic tapes; optical media, such as CD-ROM disks and DVDs; magneto-optical media, such as optical disks; and hardware devices specifically configured to store and execute program instructions, such as read-only memory (ROM), random access memory (RAM), flash memory, etc. Examples of program instructions include machine code (e.g., code generated by a compiler) and files containing high-level code that can be executed by a computer by using an interpreter. The described hardware devices can be configured to act as one or more software modules to perform the operations and methods described above, and vice versa. Additionally, the computer-readable storage media can be distributed in networked computer systems and can store and execute computer-readable code or program instructions in a decentralized manner.

[0154] Example 6

[0155] Another aspect of the present invention further provides a device. Refer to Figure 9 as shown Figure 9 which shows a schematic diagram of a device provided by an embodiment of the present invention.

[0156] The device may include a memory 50 and a processor 51. A computer program is stored in the memory 50, and when the processor 51 executes the computer program stored in the memory 50, it can implement the fluid recognition model construction method or the fluid recognition method as described above.

[0157] In some embodiments, when the computer program stored in the storage medium is executed by the processor, it can implement the fluid recognition model construction method as described above:

[0158] For sample fractured reservoirs corresponding to different types of original fluids, the following steps are respectively executed:

[0159] Obtain a first resistivity at a first position and a second resistivity at a second position in the sample fractured reservoir;

[0160] Calculate the log dual laterolog ratio of the sample fractured reservoir based on the first resistivity and the second resistivity;

[0161] Based on the acoustic travel time and the logarithm of the dual laterolog ratio of the sample fractured reservoir, an acoustic travel time - logarithm of dual laterolog ratio model of the sample fractured reservoir is constructed, and a fluid identification model is constructed based on the acoustic travel time - logarithm of dual laterolog ratio models corresponding to different types of original fluids.

[0162] Among them, the sample fractured reservoir can be measured by using conventional resistivity measurement methods in the art. Among them, the first resistivity corresponds to the resistivity of the displaced fluid in the fractured reservoir at the first position, and the second resistivity corresponds to the resistivity of the original fluid in the fractured reservoir at the second position.

[0163] The types of the original fluids can include at least two of oil and gas, water, gas, and gas - water mixture, and the fracture occurrence of the fractured reservoir can include low - angle fractures, diagonal fractures, or high - angle fractures.

[0164] Based on the first resistivity and the second resistivity, the logarithm of the dual laterolog ratio of the sample fractured reservoir is calculated by using the following expression:

[0165]

[0166] Where R s represents the first resistivity, R d represents the second resistivity, and lgRds represents the logarithm of the dual laterolog ratio.

[0167] When the processor 51 in the device executes the computer program in the memory 50, it can implement the above - mentioned fluid identification model construction method. For the sample fractured reservoir corresponding to different types of original fluids, by obtaining the first resistivity at the first position and the second resistivity at the second position in the sample fractured reservoir, where the original fluid in the sample fractured reservoir at the first position is completely displaced, and at the second position, the original fluid remains in the sample fractured reservoir. Based on the first resistivity and the second resistivity, the logarithm of the dual laterolog ratio of the sample fractured reservoir is calculated, and then based on the acoustic travel time and the logarithm of the dual laterolog ratio of the sample fractured reservoir, an acoustic travel time - logarithm of dual laterolog ratio model of the sample fractured reservoir is constructed, and a fluid identification model is constructed based on the acoustic travel time - logarithm of dual laterolog ratio models corresponding to different types of original fluids. It can achieve the beneficial effects of simple execution, clear and easy - to - obtain parameters, wide application range, and strong applicability, and can be applied to complex reservoirs such as tight sandstone, volcanic rock, and carbonate.

[0168] In another embodiment, when the computer program stored in the storage medium is executed by the processor, it can implement the above - mentioned fluid identification method:

[0169] Obtain the first resistivity at the first position and the second resistivity at the second position in the target fractured reservoir, where at the first position, the fluid in the target fractured reservoir is completely displaced, and at the second position, the fluid remains in the target fractured reservoir;

[0170] Calculate the log dual laterolog ratio in the target fractured reservoir based on the first resistivity and the second resistivity;

[0171] Identify the fluid in the target fractured reservoir by using a fluid identification model based on the acoustic travel time difference and the log dual laterolog ratio of the target fractured reservoir.

[0172] Or,

[0173] Identify the target fractured reservoir by using the acoustic travel time difference and resistivity contrast method;

[0174] Obtain the first resistivity at the first position and the second resistivity at the second position in the target fractured reservoir, where the fluid in the target fractured reservoir is completely displaced at the first position and there is fluid remaining in the target fractured reservoir at the second position;

[0175] Calculate the log dual laterolog ratio in the target fractured reservoir based on the first resistivity and the second resistivity;

[0176] Identify the fluid in the target fractured reservoir by using a fluid identification model based on the acoustic travel time difference and the log dual laterolog ratio of the target fractured reservoir.

[0177] Wherein, the types of the original fluid may include at least two of oil and gas, water, gas, and gas-water mixture, and the fracture occurrence of the fractured reservoir may include low-angle fractures, inclined fractures, or high-angle fractures.

[0178] Based on the first resistivity and the second resistivity, calculate the log dual laterolog ratio of the sample fractured reservoir by using the following expression:

[0179]

[0180] Where R s represents the first resistivity, R d represents the second resistivity, and lgRds represents the log dual laterolog ratio.

[0181] When the processor 51 in the device executes the computer program in the memory 50, it applies the fluid identification model constructed in the first embodiment above for fluid identification. First, it identifies the target fractured reservoir based on the method of acoustic travel time difference and resistivity. By obtaining the first resistivity at the first position and the second resistivity at the second position in the target fractured reservoir, where at the first position, the fluid in the target fractured reservoir is completely displaced, and at the second position, there is still fluid in the target fractured reservoir. Calculate the logarithm of the dual laterolog ratio in the target fractured reservoir based on the first resistivity and the second resistivity. Finally, based on the acoustic travel time difference and the logarithm of the dual laterolog ratio of the target fractured reservoir, use the fluid identification model to identify the fluid in the target fractured reservoir. It can achieve the beneficial effects of clear parameters and easy acquisition, without considering the influence of various factors, a wider application range, stronger adaptability, and being conducive to more convenient fluid identification. In addition, the acoustic travel time difference measured during the process of identifying the target fractured reservoir can be further applied to fluid identification, realizing the multiple utilization of measurement data, and further facilitating the improvement of the convenience of fluid identification.

[0182] It should be noted that the device may include one or more memories 50 and processors 51, and the memory 50 and the processor 51 may be connected through a bus or other means. The memory 50, as a non-volatile computer-readable storage medium, can be used to store non-volatile software programs, non-volatile computer-executable programs, and modules. The processor 51 executes various functional applications and data processing of the device by running the non-volatile software programs, instructions, and modules stored in the memory, that is, implements the above-mentioned fluid identification model construction method or the fluid identification method as described above.

[0183] Although the disclosed embodiments of the present invention are as above, the content described is only an embodiment adopted for the convenience of understanding the present invention and is not intended to limit the present invention. Any person skilled in the art within the technical field to which the present invention pertains, without departing from the spirit and scope disclosed by the present invention, can make any modifications and changes in the form of implementation and details, but the protection scope of the present invention shall still be subject to the scope defined by the appended claims.

Claims

1. A method for constructing a fluid recognition model, characterized in that, At a first position, the original fluid in the sample fractured reservoir is completely displaced, and at a second position, the original fluid is retained in the sample fractured reservoir. The method for constructing the fluid identification model includes: for the sample fractured reservoir corresponding to different types of the original fluid, respectively performing the following steps: Obtain a first resistivity at the first position and a second resistivity at the second position in the sample fractured reservoir; Calculate the log dual laterolog ratio of the sample fractured reservoir based on the first resistivity and the second resistivity; Based on the acoustic travel time and the log dual laterolog ratio of the sample fractured reservoir, construct an acoustic travel time - log dual laterolog ratio model of the sample fractured reservoir, so as to construct the fluid identification model based on the acoustic travel time - log dual laterolog ratio models respectively corresponding to different types of the original fluid.

2. The method according to claim 1, characterized in that Based on the first resistivity and the second resistivity, calculate the log dual laterolog ratio of the sample fractured reservoir by using the following expression: where R s represents the first resistivity, R d represents the second resistivity, and lgRds represents the log dual laterolog ratio.

3. The method according to claim 1 or 2, characterized in that, The types of the original fluid include at least two of oil and gas, water, gas, and gas - water mixture.

4. The method according to claim 1, wherein The fracture occurrence of the sample fractured reservoir includes low - angle fractures, diagonal fractures, or high - angle fractures.

5. A fluid identification method, characterized in that, Performing fluid identification by using the fluid identification model constructed by using the method for constructing a fluid identification model according to any one of claims 1 to 4 above, includes: Obtain a first resistivity at the first position and a second resistivity at the second position in the target fractured reservoir, wherein at the first position, the fluid in the target fractured reservoir is completely displaced, and at the second position, the fluid is retained in the target fractured reservoir; Calculate the log dual laterolog ratio in the target fractured reservoir based on the first resistivity and the second resistivity; Based on the acoustic travel time and the log dual laterolog ratio of the target fractured reservoir, identify the fluid in the target fractured reservoir by using the fluid identification model.

6. The method according to claim 5, characterized in that, Based on the first resistivity and the second resistivity, calculate the log dual laterolog ratio of the target fractured reservoir by using the following expression: where R s represents the first resistivity, R d represents the second resistivity, and lgRds represents the log dual laterolog ratio.

7. The method according to claim 5, characterized in that, The method further includes: identifying the target fractured reservoir by using the acoustic travel time and resistivity comparison method.

8. A fluid recognition model construction device, characterized in that, Includes: An acquisition module, which is used to obtain a first resistivity at the first position and a second resistivity at the second position in the sample fractured reservoir corresponding to different types of the original fluid, wherein at the first position, the original fluid in the sample fractured reservoir is completely displaced, and at the second position, the original fluid is retained in the sample fractured reservoir; A calculation module, which is used to calculate the log dual laterolog ratio of the sample fracture based on the first resistivity and the second resistivity; A construction module, which is used to construct an acoustic travel time - log dual laterolog ratio model of the sample fractured reservoir based on the acoustic travel time and the log dual laterolog ratio of the sample fractured reservoir, so as to construct the fluid identification model based on the acoustic travel time - log dual laterolog ratio models respectively corresponding to different types of the original fluid.

9. A storage medium, characterized in that, A computer program is stored in the storage medium, and when the computer program is executed by a processor, it can implement the fluid recognition model construction method described in any one of claims 1 to 4 above or the fluid recognition method described in any one of claims 5 to 7 above.

10. A device, characterized in that, It includes: A memory and a processor. A computer program is stored in the memory, and when the computer program is executed by the processor, it can implement the fluid recognition model construction method described in any one of claims 1 to 4 above or the fluid recognition method described in any one of claims 5 to 7 above.

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