Method for predicting water invasion dominant channel of carbonate gas reservoir
By constructing the reservoir seepage quality index R and simulated deep lateral resistivity curve, the water invasion advantage channel of the reservoir in the wellbore of the carbonate gas reservoir is accurately predicted, and the problem of low prediction accuracy in the existing technology is solved, and efficient carbonate gas reservoir development is achieved.
Patent Information
- Application Number
- CN202311177935.2
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2023-09-11
- Publication Date
- 2025-03-11
AI Technical Summary
When the prior art predicts the water invasion advantage channels of reservoirs in the wellbore of carbonate gas reservoirs, the accuracy is not high and easy to be misjudged, which affects the efficient development of carbonate gas reservoirs.
By constructing the reservoir seepage quality index R, combining the ratio of porosity and permeability, the favorable target sections of water invasion are divided, and the deep lateral resistivity curve is simulated in these sections, and the actual value is compared with the simulated value to determine the dominant channel section of water invasion.
Accurate prediction of the reservoir water invasion advantage channels in the wellbore of carbonate gas reservoir is achieved, the quantitative and accurate predictions are improved, and the rational and efficient development of carbonate gas reservoirs is supported.
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Figure CN119598669A_ABST
Abstract
Description
Technical Field
[0001] The invention belongs to the technical field of oil and gas reservoir exploration and development, and in particular relates to a method for predicting a dominant channel of water invasion in a carbonate gas reservoir. Background Art
[0002] With the continuous development of carbonate gas reservoirs, marginal water bodies or bottom water bodies will enter the wellbore along the high permeability strip at the water invasion front. Specifically, the development gas wells in the water invasion front zone suddenly produce formation water or the water production suddenly increases. The development gas wells can even be shut down due to the increase in water production, which seriously affects the efficient development of the gas reservoir. Therefore, it is very important to predict the dominant water invasion channel in the wellbore in advance through technical means. After the development gas wells in the water invasion front zone see water, water control measures such as water plugging can be taken for the predicted dominant water invasion channel to achieve the purpose of maintaining the efficient production of the development gas wells. At the same time, a comprehensive analysis is conducted on the predicted dominant water invasion channels of each well in the water invasion front zone to understand the water invasion law of the gas reservoir. It is possible to predict in advance which layers of which development gas wells will see water. Then, by optimizing the production allocation of these development gas wells and formulating reasonable water control measures, the water invasion path can be changed or the water invasion speed can be slowed down in the water invasion front zone, thereby ensuring the efficient development of the gas reservoir.
[0003] For gas reservoirs with weak heterogeneity, the greater the porosity, the greater the permeability, and the porosity and permeability show a highly correlated positive correlation. Water invasion mainly enters the wellbore of the developed gas well along the high-porosity and high-permeability reservoir section. On the basis of the overall monitoring of the gas reservoir to determine the water invasion front zone, the porosity and permeability interpreted by the reservoir logging can be analyzed in the wellbore to predict the dominant water invasion channel. For most carbonate oil and gas reservoirs, due to the combined effects of sedimentation, diagenesis, and tectonic structure, the pore type, dissolution degree, and fracture development degree of the reservoir are complex and diverse, and the formation has strong heterogeneity, which is specifically manifested as follows: the single positive correlation between porosity and permeability is not significant, and there are many situations such as low porosity and high permeability, high porosity and low permeability, and high porosity and high permeability. At this time, conventional interpretation of logging data can obtain relatively reliable reservoir porosity values, but since the positive correlation between porosity and permeability in the reservoir is not significant, the problem is that the same porosity corresponds to many permeabilities of different sizes. The permeability interpreted by logging is only based on the identification and division of reservoir pore structure, and a relatively coarse permeability interpretation model is established for different reservoir pore structures. The permeability interpreted by logging at this time does not take into account the differences in the degree of dissolution and fracture development inside the reservoir. It is just that under the condition of assuming that the reservoir is relatively homogeneous under different reservoir pore structure conditions, the error between the permeability interpreted by logging and the actual permeability of each section of the reservoir is still large. At this time, it is difficult to accurately predict the dominant channel for water invasion by only using reservoir logging to interpret porosity and permeability.
[0004] The existing method for monitoring the dominant water invasion channel in the wellbore of a carbonate gas reservoir development gas well mainly adopts saturation monitoring logging: the water invasion layer section is determined by using the difference between the water saturation of the reservoir in the wellbore during saturation logging and the water saturation calculated by logging when the development gas well is completed. The water invasion layer section is the dominant water invasion channel actually monitored. This saturation monitoring method can only identify the dominant water invasion channel under the condition that water invasion has occurred in the reservoir in the wellbore, but cannot predict the dominant water invasion channel in the development gas well that has not been water invaded. It fails to prepare for a rainy day, and saturation monitoring logging is only measured in individual wells. It is urgent to use conventional logging data to predict the dominant water invasion channel in the wellbore reservoir. Previous researchers have also done some research on the identification and prediction of dominant water invasion channels in carbonate gas reservoirs. However, most of these methods are about identifying the water invasion dominant channels of gas reservoirs in the water invasion front zone by using existing logging interpretation results, modeling and other means (Chongqing University of Science and Technology, fault block oil and gas fields), but do not focus on the prediction of water invasion dominant channels in the wellbore, or use the porosity and permeability of the reservoir directly as the water invasion dominant channels of the reservoir in the wellbore (natural gas industry). Although these methods of identifying or predicting water invasion dominant channels have a certain effect in actual production, inaccurate prediction of water invasion dominant channels in the reservoir in the wellbore will directly affect the characterization of the water invasion dominant channels of gas reservoirs in the water invasion front zone, and carbonate gas reservoirs do not consider the influencing factors such as the degree of dissolution or the degree of fracture development in the wellbore, which leads to misjudgment of the prediction of water invasion dominant channels.
[0005] Therefore, in the process of using existing technical methods to predict the dominant water invasion channels of the reservoir in the wellbore of carbonate gas reservoirs, there are certain defects such as incomplete quantitative characterization, many uncertain factors, and easy misjudgment, which in turn affects the accurate prediction of the dominant water invasion channels of the reservoir in the wellbore of carbonate gas reservoirs, and has an adverse impact on the rational and efficient development of such carbonate gas reservoirs. Summary of the invention
[0006] The purpose of the present invention is to provide a method for predicting the dominant channel of water invasion in carbonate gas reservoirs, so as to solve the problem of low accuracy and easy misjudgment in the process of predicting the dominant channel of water invasion in carbonate gas reservoir wellbore in the prior art.
[0007] In order to solve the above technical problems, the present invention provides a technical solution of a method for predicting water invasion dominant channels of carbonate gas reservoirs, comprising the following steps:
[0008] 1) Obtain the porosity φ and permeability K of the water invasion section interpreted by each saturation monitoring well in the study area, construct the reservoir seepage quality index R = K / φ, and determine the lower limit of the reservoir seepage quality index R where water invasion can occur based on the intersection relationship between the reservoir seepage quality index and porosity of the water invasion section interpreted by each saturation monitoring well in the study area;
[0009] 2) Obtain the reservoir section of the single well to be predicted and the porosity and permeability of each depth sampling point, calculate the reservoir seepage quality index curve of the single well prediction section using the reservoir seepage quality index R expression constructed in step 1), and divide the favorable target section for water invasion in the reservoir section of the single well to be predicted according to the lower limit of the reservoir seepage quality index R;
[0010] 3) The actual value of the deep lateral resistivity of each depth sampling point in the single well section to be predicted is obtained, and the simulated deep lateral resistivity is constructed by simulation and assignment in the single well section to be predicted. In the divided water invasion favorable target section, when the actual value of the deep lateral resistivity is less than the simulated deep lateral resistivity value, the water invasion favorable target section is determined to be a reservoir water invasion advantageous channel section, otherwise, the water invasion favorable target section is determined to be a non-reservoir water invasion advantageous channel section.
[0011] The beneficial effects of the above technical scheme are as follows: first, a reservoir seepage quality index R is constructed, and the single well section to be predicted is roughly divided into favorable target sections for water invasion. Then, a simulated deep lateral resistivity curve is simulated in the single well section to be predicted. By comparing the difference between the simulated deep lateral resistivity and the deep lateral resistivity, the reservoir water invasion dominant channel section is finally obtained. Through the two-level division, the water invasion dominant channel of the reservoir in the wellbore of the carbonate gas reservoir is quantitatively and accurately predicted, which is consistent with the water invasion section monitoring result of the saturation monitoring well, thereby supporting the deepening of the understanding of the water invasion law of carbonate gas reservoir development and laying a foundation for the rational and efficient exploration and development of carbonate gas reservoirs.
[0012] Furthermore, the porosity φ, permeability K of the water invasion section interpreted by each saturation monitoring well in the study area and the reservoir section of the well section to be predicted in a single well are obtained from the logging interpretation results table of conventional logging.
[0013] The beneficial effects of the above technical solution are: the parameters determined by the entire method are certain and accurate, and the final discrimination effect is also more precise.
[0014] Furthermore, the lower limit of the reservoir seepage quality index R is taken as the minimum value of the reservoir seepage quality index of the water invasion section interpreted by each saturation monitoring well in the study area and the reservoir seepage quality index of the water invasion section interpreted in the porosity cross-plot.
[0015] The beneficial effect of the above technical solution is: the intersection relationship diagram of reservoir seepage quality index and porosity can reflect that the porosity distribution range is very wide, and the geological background that the porosity alone cannot distinguish the favorable target section for water invasion can be better distinguished by using the reservoir seepage quality index.
[0016] Furthermore, the division of favorable target sections for water invasion according to the lower limit of the reservoir seepage quality index R is determined by comparing the seepage quality index of the reservoir section with the lower limit of the reservoir seepage quality index R: when the reservoir seepage quality index of the reservoir section is greater than or equal to the lower limit of the reservoir seepage quality index R, the reservoir section is a favorable target section for water invasion, otherwise the reservoir section is an unfavorable target section.
[0017] The beneficial effect of the above technical solution is that by providing a specific operating criterion for dividing the favorable target section for water invasion using the lower limit R of the reservoir seepage quality index, the process of the solution is made more certain and complete.
[0018] Furthermore, a simulated deep lateral resistivity is constructed by simulation and assignment in the well section to be predicted of a single well, and the construction method is as follows: in each divided water invasion favorable target section, the actual values of the deep lateral resistivity corresponding to the top depth and the bottom depth are used to perform interpolation simulation to obtain the simulated deep lateral resistivity curve of each water invasion favorable target section, and in the non-water invasion favorable target section, the actual values of the deep lateral resistivity corresponding to each depth are assigned to the simulated deep lateral resistivity curve, so as to obtain a complete simulated deep lateral resistivity curve in the well section to be predicted of the single well.
[0019] The beneficial effects of the above technical scheme are: the actual values of deep lateral resistivity corresponding to the top depth and bottom depth are interpolated and simulated to obtain the simulated deep lateral resistivity curves of each water invasion favorable target section, and the non-water invasion favorable target section is assigned a value, and finally a complete simulated deep lateral resistivity curve is obtained in the well section to be predicted in a single well, which is convenient for subsequent comparison, making the whole scheme more certain and complete. BRIEF DESCRIPTION OF THE DRAWINGS
[0020] Figure 1 It is a flow chart of the method for predicting the dominant channel of water invasion in carbonate gas reservoirs of the present invention;
[0021] Figure 2 It is a cross-correlation diagram of reservoir seepage quality index and reservoir porosity interpreted by well logging in 32 water invasion sections in an embodiment of the present invention;
[0022] Figure 3 It is a diagram showing the conventional logging combination results, saturation monitoring results and water invasion dominant channel prediction effect diagram of the predicted well section 5640-5738m of Well A in the embodiment of the present invention. DETAILED DESCRIPTION
[0023] In order to make the purpose, technical solutions and advantages of the present invention more clear, the present invention is further described in detail below with reference to the accompanying drawings and embodiments.
[0024] Example of a method for predicting dominant channels of water invasion in carbonate gas reservoirs:
[0025] Carbonate gas reservoirs are an important aspect of current oil and gas development. Due to the combined effects of sedimentation, diagenesis, and tectonic structure, most carbonate oil and gas reservoirs have complex and diverse reservoir pore types, dissolution degrees, and fracture development degrees. The strata have strong heterogeneity, which is specifically manifested in that the single positive correlation between porosity and permeability is not significant, and there are many situations such as low porosity and high permeability, high porosity and low permeability, and high porosity and high permeability. There are also influencing factors such as differences in the degree of dissolution or fracture development within the reservoir.
[0026] The present invention aims to solve the problems of low accuracy and easy misjudgment in carbonate gas reservoir prediction. An effective prediction method is proposed. The flowchart of the method is as follows: Figure 1 As shown, the specific implementation steps of this method are as follows:
[0027] 1) In the study area, the porosity φ and permeability K of the water invasion section interpreted by each saturation monitoring well are obtained through the logging interpretation results table of conventional logging, and the reservoir seepage quality index R = K / φ is constructed. The intersection relationship diagram between the reservoir seepage quality index R and the porosity φ is established. The minimum value of the reservoir seepage quality index is determined by the intersection relationship diagram as the lower limit of the reservoir seepage quality index, which is used to divide the favorable target section for water invasion and the non-favorable target section for water invasion.
[0028] 2) Obtain the reservoir section of the single well to be predicted and the porosity and permeability of each depth sampling point, calculate the reservoir seepage quality index curve of the single well prediction section using the reservoir seepage quality index R expression constructed in step 1), and divide the favorable target section for water invasion in the reservoir section of the single well to be predicted according to the lower limit R of the reservoir seepage quality index;
[0029] 3) The actual value of the deep lateral resistivity of each sampling point at each depth of the single well section to be predicted is obtained. In the single well section to be predicted, the actual value of the deep lateral resistivity corresponding to the top depth and the bottom depth of each water invasion favorable target section is interpolated and simulated to obtain a simulated deep lateral resistivity curve. In the non-water invasion favorable target section, the deep lateral resistivity corresponding to each depth is assigned to the simulated deep lateral resistivity curve, thereby obtaining a complete simulated deep lateral resistivity curve of the single well section to be predicted. When the actual value of the deep lateral resistivity is less than the simulated deep lateral resistivity value, the water invasion favorable target section is determined to be a reservoir water invasion advantageous channel section, otherwise, the water invasion favorable target section is determined to be a non-reservoir water invasion advantageous channel section.
[0030] The technical scheme of the method for predicting water invasion dominant channels of carbonate gas reservoirs of the present invention is further explained below by taking the carbonate gas reservoir of gas field A as an example in conjunction with the accompanying drawings. The reservoir type of group A in gas field A is mainly a carbonate reservoir of oolitic beach phase at the edge of the platform. Due to the joint control of sedimentation, diagenesis and tectonic action, the reservoir exhibits extremely strong heterogeneity.
[0031] This embodiment takes the A group gas reservoir of the A gas field as an example to introduce the prediction method of the dominant channel of water invasion in carbonate gas reservoirs. Figure 1 The flowchart shown includes the following steps:
[0032] 1) Obtain the porosity and permeability corresponding to the water invasion section interpreted by each saturation monitoring well in the study area, and calculate the reservoir seepage quality index of each water invasion section:
[0033] Firstly, a reservoir seepage quality index R is constructed in carbonate gas reservoirs. The reservoir seepage quality index R is defined as the ratio of the permeability K and the porosity φ interpreted by logging, that is, R = K / φ. R can reflect the parameters of reservoir seepage quality to a certain extent. Since there are many situations in carbonate gas reservoirs, such as low porosity and high permeability, high porosity and low permeability, and high porosity and high permeability, conventional interpretation of logging data can obtain relatively reliable reservoir porosity values. However, since the positive correlation between porosity and permeability in the reservoir is not significant, the problem is that the same porosity corresponds to many permeabilities of different sizes. The permeability interpreted by logging is only based on the identification and division of reservoir pore structure, and a relatively coarse permeability interpretation model is established for different reservoir pore structures. At this time, the logging interpretation permeability does not take into account the internal dissolution degree and The difference in the degree of fracture development is that under the condition that the reservoir is assumed to be relatively homogeneous under different reservoir pore structure conditions, the error between the permeability interpreted by logging and the actual permeability of each section of the reservoir is still large. Only using the reservoir porosity or permeability parameter interpreted by logging cannot accurately reflect the true seepage capacity of the reservoir. Therefore, the reservoir seepage quality index R is constructed. The ratio of permeability K and porosity φ can reflect the permeability corresponding to the unit porosity of the reservoir. At this time, R to a certain extent better reflects the true permeability of the reservoir, and then reflects the size of the reservoir seepage capacity. The larger the R, the stronger the seepage capacity of the reservoir section, and the higher the possibility that the corresponding reservoir section will become the dominant channel for water invasion in the water invasion front zone. The constructed R provides a quantitative parameter that can be used to screen out the dominant channel section for water invasion in the reservoir section in the wellbore.
[0034] Then, for the 5 saturation monitoring wells in Group B of Gas Field A that have detected water invasion sections, the reservoir porosity φ and permeability K values obtained from the logging interpretation results table corresponding to the 32 water invasion sections were obtained, and the reservoir seepage quality index R corresponding to the 32 water invasion sections was calculated;
[0035] 2) According to the cross-relationship between reservoir seepage quality index and porosity of the water invasion section interpreted by each saturation monitoring well in the study area, the lower limit of reservoir seepage quality index where water invasion can occur is determined:
[0036] Through the cross-correlation diagram of reservoir seepage quality index R and reservoir porosity φ corresponding to 32 water invasion sections, as shown in Figure 2As shown in the figure, since the larger the R, the stronger the seepage capacity of the reservoir section, the higher the possibility that the corresponding reservoir section will become the dominant channel of water invasion in the water invasion front zone, the minimum value of the reservoir seepage quality index of the water invasion section explained in the cross-plot is taken as the lower limit of the reservoir seepage quality index where water invasion can occur in the reservoir, and thus the lower limit of the reservoir seepage quality index where water invasion can occur in Group A of Gas Field A is determined to be 0.15mD / %;
[0037] 3) Obtain the reservoir section in the single well prediction section and the porosity, permeability, and deep lateral resistivity logging response values of each depth sampling point, calculate the reservoir seepage quality index curve of the single well prediction section, and divide the reservoir section of the single well prediction section into a favorable target section for water invasion according to the lower limit of the reservoir seepage quality index for the reservoir that can undergo water invasion determined in step 2):
[0038] In this embodiment, the method for predicting the dominant channel of reservoir water invasion is described by selecting Well A in Gas Field A. Well A is a development gas well in the water invasion front zone of Group A carbonate gas reservoir in Gas Field A. The conventional logging combination results, saturation monitoring results and water invasion dominant channel prediction effect diagram of the predicted well section 5640-5738m of Well A are shown in the figure. Figure 3 As shown, Figure 3 The solid line in the third channel, the solid line in the fourth channel, and the dotted line in the fifth channel are the porosity φ, permeability K, and deep lateral resistivity R of well A, respectively. t The reservoir seepage quality index R of each sampling point in the predicted well section of Well A is calculated using the expression of the reservoir seepage quality index R constructed in step 1). Figure 3 The dotted line in the fourth channel is the calculated reservoir seepage quality index curve. According to the lower limit of the reservoir seepage quality index of 0.15mD / % determined in step 2), the favorable target section for water invasion is divided in the reservoir section by comparing the seepage quality index R of the reservoir section with the lower limit of the reservoir seepage quality index for water invasion: when the seepage quality index of the reservoir section is greater than or equal to the lower limit of the reservoir seepage quality index for water invasion, the reservoir section is a favorable target section for water invasion, otherwise the reservoir section is a non-favorable target section. The predicted well section of Well A is divided into a favorable target section for water invasion. Figure 3 The ninth track in the middle is divided into 24 favorable target sections for water invasion;
[0039] 4) Construct a simulated deep lateral resistivity curve in the predicted well section of a single well, and predict the reservoir water invasion advantage channel section by comparing the difference between the simulated deep lateral resistivity and the deep lateral resistivity in each water invasion favorable target section:
[0040] In the reservoir of carbonate gas reservoir wellbore, the permeability of the reservoir can determine the depth of drilling fluid invasion. The deep lateral resistivity is affected by the degree of drilling fluid invasion. In the same section of the reservoir, the low-depth lateral resistivity reflects that the real permeability of the reservoir is relatively large, and the high-depth lateral resistivity reflects that the real permeability of the reservoir is relatively small. Due to the extremely strong heterogeneity inside the carbonate gas reservoir, the degree of dissolution and the degree of fracture development inside the reservoir are different at different locations. The higher the degree of dissolution during diagenesis or the more developed the fractures, the higher the corresponding real permeability of the formation, and the lower the corresponding deep lateral resistivity. In the non-favorable target section determined in step 3), since the seepage quality index of the reservoir is relatively low, the corresponding deep lateral resistivity is generally high. Based on the above analysis, this scheme constructs a simulated deep lateral resistivity curve, specifically in the division In each water invasion favorable target section, the deep lateral resistivity values corresponding to the top depth and the bottom depth are interpolated and simulated to obtain a simulated deep lateral resistivity curve. In the non-water invasion favorable target section, the deep lateral resistivity values corresponding to each depth are assigned to the simulated deep lateral resistivity curve, and then a continuous simulated deep lateral resistivity curve is constructed in the single well section to be predicted. Since the deep lateral resistivity values corresponding to the top depth and the bottom depth of the water invasion target section are adjacent to the non-water invasion favorable target section, the water invasion advantageous channel section can be reflected by comparing the difference between the simulated deep lateral resistivity and the deep lateral resistivity in the water invasion favorable target section. When the deep lateral resistivity is less than the simulated deep lateral resistivity, the water invasion favorable target section is the reservoir water invasion advantageous channel section, otherwise the water invasion favorable target section is the reservoir water invasion advantageous channel section or the non-reservoir water invasion advantageous channel section.
[0041] In the predicted well section of Well A, the deep lateral resistivity values corresponding to the top depth and bottom depth of the 24 water invasion favorable target sections were linearly interpolated in each divided water invasion favorable target section to obtain the simulated deep lateral resistivity values corresponding to each depth sampling point in each water invasion favorable target section. The deep lateral resistivity values corresponding to each depth in the non-water invasion favorable target section were assigned to the simulated deep lateral resistivity curve, and then a continuous simulated deep lateral resistivity curve was constructed in the single well to be predicted well section. Figure 3 The solid line in the fifth track is the constructed simulated deep lateral resistivity curve. Then, the simulated deep lateral resistivity and deep lateral resistivity are compared in each favorable target section for water invasion to predict the dominant channel section for reservoir water invasion. Figure 3 The tenth track in the middle is the predicted 11 reservoir water invasion dominant channel sections. Figure 3The eighth track in the middle shows seven water invasion sections interpreted by saturation monitoring logging. Comparative analysis shows that since the interpretation accuracy of the water invasion sections interpreted by saturation monitoring logging is relatively coarse, the water invasion dominant channel sections of the reservoir in the wellbore of carbonate gas reservoir predicted by the method of the present invention using conventional logging data are all within the water invasion sections interpreted by saturation monitoring logging, indicating that the water invasion dominant channel sections of the reservoir in the wellbore of carbonate gas reservoir predicted by conventional logging data have a good correspondence with the water invasion sections interpreted by saturation monitoring logging, further proving that the prediction method of water invasion dominant channels of carbonate gas reservoir reservoirs is feasible and effective, laying a foundation for deepening the understanding of water invasion laws in the water invasion front zone of carbonate gas reservoirs, and further providing technical support for formulating reasonable and efficient development technical countermeasures for carbonate gas reservoirs.
[0042] Specific implementation methods are given above, but the present invention is not limited to the described implementation methods. The basic idea of the present invention lies in the above basic scheme. For ordinary technicians in this field, it does not take creative work to design various deformed models, formulas, and parameters according to the teachings of the present invention. Changes, modifications, substitutions, and variations of the implementation methods without departing from the principles and spirit of the present invention still fall within the scope of protection of the present invention.
Claims
1. A method for predicting dominant channels of water invasion in carbonate gas reservoirs, characterized in that: The following steps are involved: 1) Obtain the porosity φ and permeability K of the water invasion section interpreted by each saturation monitoring well in the study area, construct the reservoir seepage quality index R = K / φ, and determine the lower limit of the reservoir seepage quality index R where water invasion can occur based on the intersection relationship between the reservoir seepage quality index and porosity of the water invasion section interpreted by each saturation monitoring well in the study area; 2) Obtain the reservoir section of the single well to be predicted and the porosity and permeability of each depth sampling point, calculate the reservoir seepage quality index curve of the single well prediction section using the reservoir seepage quality index R expression constructed in step 1), and divide the favorable target section for water invasion in the reservoir section of the single well to be predicted according to the lower limit R of the reservoir seepage quality index; 3) The actual value of the deep lateral resistivity of each depth sampling point in the single well section to be predicted is obtained, and the simulated deep lateral resistivity is constructed by simulation and assignment in the single well section to be predicted. In the divided water invasion favorable target section, when the actual value of the deep lateral resistivity is less than the simulated deep lateral resistivity value, the water invasion favorable target section is determined to be a reservoir water invasion advantageous channel section, otherwise, the water invasion favorable target section is determined to be a non-reservoir water invasion advantageous channel section.
2. The method for predicting dominant channels of water invasion in carbonate gas reservoirs according to claim 1, characterized in that: The porosity φ, permeability K of the water invasion section interpreted by each saturation monitoring well in the study area and the reservoir section of the well section to be predicted in a single well are obtained through the logging interpretation result table of conventional logging.
3. The method for predicting dominant channels of water invasion in carbonate gas reservoirs according to claim 1, characterized in that: The lower limit of the reservoir seepage quality index R is the minimum value of the reservoir seepage quality index of the water invasion section explained by each saturation monitoring well in the study area and the reservoir seepage quality index of the water invasion section explained in the porosity cross-plot as the lower limit of the reservoir seepage quality index.
4. The method for predicting dominant channels of water invasion in carbonate gas reservoirs according to claim 1, characterized in that: The division of the favorable target section for water invasion according to the lower limit of the reservoir seepage quality index R is determined by comparing the seepage quality index of the reservoir section with the lower limit of the reservoir seepage quality index R: when the reservoir seepage quality index of the reservoir section is greater than or equal to the lower limit of the reservoir seepage quality index R, the reservoir section is a favorable target section for water invasion, otherwise the reservoir section is an unfavorable target section.
5. The method for predicting dominant channels of water invasion in carbonate gas reservoirs according to claim 1, characterized in that: The simulated deep lateral resistivity is constructed by simulation and assignment in the single well section to be predicted. The construction method is as follows: in each divided water invasion favorable target section, the actual values of the deep lateral resistivity corresponding to the top depth and the bottom depth are used to perform interpolation simulation to obtain the simulated deep lateral resistivity curve of each water invasion favorable target section, and in the non-water invasion favorable target section, the actual values of the deep lateral resistivity corresponding to each depth are assigned to the simulated deep lateral resistivity curve, so as to obtain a complete simulated deep lateral resistivity curve in the single well section to be predicted.