Method for improving reservoir description precision based on horizontal well data

Abstract

The invention relates to the technical field of oil reservoir fine discrimination, in particular to a method for improving reservoir description precision based on horizontal well data. The method comprises the steps that a target reservoir is determined, logging information of the target reservoir is obtained, stratigraphic comparison and reservoir parameter interpretation are conducted on the target reservoir according to the logging information, the rock-electricity relation of a horizontal well and a vertical well is analyzed, and a horizontal well phase judgment standard is established according to the rock-electricity relation of the horizontal well and the vertical well in cooperation with reservoir characteristics of the target reservoir. And performing continuous description on the horizontal section sedimentary microfacies of the target reservoir according to the facies judgment standard, constructing a three-dimensional geologic model of the target reservoir, establishing a straight-flat combined facies judgment mode according to the three-dimensional geologic model, and performing section-by-section judgment and comprehensive phasing on the target reservoir through the straight-flat combined facies judgment mode. According to the method provided by the invention, the specific position of the phase change boundary can be identified, the channel scale and the reservoir communication relationship can be further determined, the injection-production relationship can be perfected by effectively improving the reservoir identification precision, and the purpose of improving the development effect can be finally achieved.

Description

Technical Field

[0001] The present invention relates to the technical field of fine discrimination of reservoir formations, and particularly to a method for improving the accuracy of reservoir description based on horizontal well data. Background Art

[0002] In continental sandstone reservoirs, large distributary channel sand bodies are developed in a relatively complex manner, with severe channel stacking, scattered remaining oil distribution. Especially for thick oil layers with prominent plane and intra-layer contradictions, it is difficult to accurately develop, with prominent inefficient and ineffective circulation phenomena and poor economic benefits.

[0003] Currently, reservoir description technologies based on vertical wells at home and abroad are relatively mature. In recent years, through comprehensive application of data such as newly drilled wells, 3D seismic, cored wells, and special logging, single sand body identification technologies have been continuously developed, and reservoir description has fully shifted from the composite sand body level to the fine description of single sand bodies. However, affected by well pattern density, there is still a certain degree of multi-solution in the prediction of inter-well sand bodies and planar microfacies combination, and inaccurate reservoir characterization directly affects the analysis of connectivity between sand bodies and oil-water migration, thereby affecting the quantitative study of remaining oil distribution. Therefore, in view of the above deficiencies, a method for improving the accuracy of reservoir description based on horizontal well data is proposed. Summary of the Invention

[0004] (I) Technical Problems to be Solved

[0005] The present invention provides a method for improving the accuracy of reservoir description based on horizontal well data to overcome the defects in the existing reservoir description process, such as strong multi-solution in the prediction of inter-well sand bodies and planar microfacies combination, inaccurate reservoir characterization, poor connectivity between sand bodies, and difficult analysis of oil-water migration due to well pattern density, resulting in the inability to continuously carry out the quantitative study of remaining oil distribution.

[0006] (II) Technical Solutions

[0007] To solve the above problems, the present invention provides a method for improving the accuracy of reservoir description based on horizontal well data, including:

[0008] Step S1: Determine the target reservoir and obtain the logging data of the target reservoir;

[0009] Step S2: Conduct stratigraphic correlation and reservoir parameter interpretation on the target reservoir according to the logging data obtained in Step S1, and analyze the litho-electric relationship between horizontal and vertical wells;

[0010] Step S3: Establish a horizontal well facies discrimination standard according to the litho-electric relationship between horizontal and vertical wells obtained in Step S2, in combination with the reservoir characteristics of the target reservoir;

[0011] Step S4: Continuously describe the sedimentary microfacies of the horizontal section of the target reservoir according to the horizontal well facies discrimination standard obtained in Step S3, and construct a 3D geological model of the target reservoir;

[0012] Step S5: Establish a straight-horizontal combined phase discrimination model based on the 3D geological model obtained in Step S4, and perform comprehensive phase determination on the target reservoir section by section through the straight-horizontal combined phase discrimination model.

[0013] Preferably, in Step S1, the logging data of the target reservoir includes vertical well logging data and horizontal well logging data, and the types of logging curves of the vertical well logging data are compatible with those of the horizontal well logging data.

[0014] Preferably, in Step S2, the reservoir parameters include resistivity. The rock electricity relationship between horizontal and vertical wells is determined by analyzing the relationship between the resistivity of the horizontal well and that of the vertical well. The calculation formula for the rock electricity relationship between horizontal and vertical wells is:

[0015]

[0016] where, R a is the resistivity of the horizontal well, Ω·m; R h is the resistivity of the horizontal well, Ω·m; θ is the angle between the axis of the electrode system and the direction of the vertical interface, °; R m is the average resistivity of the anisotropic formation, Ω·m; λ is the resistivity anisotropy coefficient.

[0017] Preferably, the calculation formula for the average resistivity of the anisotropic formation is:

[0018]

[0019] where, R m is the average resistivity of the anisotropic formation, Ω·m; R h is the horizontal resistivity, Ω·m; R v is the vertical resistivity, Ω·m.

[0020] Preferably, the introduction of the resistivity anisotropy coefficient is to describe the degree of resistivity anisotropy of the rock, and its mathematical expression is:

[0021]

[0022] In the formula: R h is the horizontal resistivity, Ω·m; R v is the vertical resistivity, Ω·m; R sd is the resistivity of the sandstone, Ω·m; R sh is the resistivity of the mudstone, Ω·m; h sd is the cumulative thickness of the sandstone, m; h sh is the cumulative thickness of the mudstone, m.

[0023] Preferably, in the step S3, the reservoir characteristics of the target reservoir include electrical properties, lithology, oil-bearing property, physical properties, and gas logging curves.

[0024] Preferably, in the step S3, the horizontal well phase discrimination standard determines the relationship between different horizontal well microfacies types and their anisotropy coefficients. The horizontal well microfacies types include distributary channel sand bodies, sandstone sand bodies, off-formation sand bodies, and inter-distributary sand bodies. The influencing factors of the anisotropy coefficient include vertical well resistivity, horizontal well resistivity, and reservoir thickness.

[0025] Preferably, in the step S4, the 3D geological model describes the relative positional relationships between the horizontal well trajectories of the target reservoir and the horizons and sand bodies respectively. The types of relative positional relationships between the horizontal well trajectories and the sand bodies include well trajectories parallel to the bedding plane, well trajectories parallel to the bedding plane without controlling the boundary, well trajectories descending within the formation, well trajectories ascending within the formation, well trajectories descending through the formation, and well trajectories ascending through the formation.

[0026] Preferably, in the step S5, the straight-horizontal combination phase discrimination mode is determined through the types of relative positional relationships between the horizontal well trajectories and the sand bodies. The phase discrimination method of the straight-horizontal combination phase discrimination mode is specifically as follows:

[0027] Well trajectories parallel to the bedding plane: controlling double boundaries, and discriminating the phase according to the relative position between the well trajectory and the abandoned channel;

[0028] Well trajectories parallel to the bedding plane without controlling the boundary: discriminating the phase according to the surrounding vertical wells or deviated wells;

[0029] Well trajectories descending within the formation: controlling a single boundary, and discriminating the phase according to the straight-horizontal combination;

[0030] Well trajectories ascending within the formation: controlling a single boundary, and discriminating the phase according to the straight-horizontal combination;

[0031] Well trajectories descending through the formation: controlling double boundaries, and the penetrated section cannot truly reflect the phase type of the current layer;

[0032] Well trajectories ascending through the formation: controlling double boundaries, and the penetrated section cannot truly reflect the phase type of the current layer.

[0033] (III) Beneficial Effects

[0034] The method for improving reservoir description accuracy based on horizontal well data provided by the present invention can not only identify the specific positions of phase change boundaries, but also further clarify the channel scale and reservoir connectivity relationship. By effectively improving the reservoir identification accuracy, the injection-production relationship is further improved, and finally the purpose of improving the development effect is achieved, providing a basis for the adjustment of measures in the transition zone. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Figure 1 is a flowchart of the method for improving reservoir description accuracy based on horizontal well data according to an embodiment of the present invention;

[0036] Figure 2 Schematic diagram of the straight-horizontal combined three-dimensional comprehensive phase discrimination method according to the embodiment of the present invention. Among them, (a) is the trajectory parallel layer control double boundary mode, (b) is the trajectory parallel layer control double boundary AU mode, (c) is the trajectory parallel layer control double boundary AD mode, (d) is the trajectory parallel layer non-control boundary mode, (e) is the trajectory downward layer control single boundary mode, (f) is the trajectory upward layer control double boundary mode, (g) is the trajectory downward through-layer control double boundary mode, (h) is the trajectory downward through-layer control double boundary CH mode, (i) is the trajectory downward through-layer control double boundary MS mode, (j) is the trajectory upward through-layer control double boundary mode, (k) is the trajectory upward through-layer control double boundary CH mode, (l) is the trajectory upward through-layer control double boundary MS mode;

[0037] Figure 3 Schematic diagram of the straight-horizontal combined three-dimensional comprehensive phase discrimination method for horizontal well B2-6-A79 according to the embodiment of the present invention. Detailed implementation manners

[0038] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without making creative efforts belong to the scope of protection of the present invention.

[0039] In addition, those of ordinary skill in the art should understand that the provided drawings are only for explaining the purpose, features and advantages of the present invention, and the drawings are not actually drawn to scale.

[0040] At the same time, unless the context clearly requires, the words such as "including", "comprising" and the like in the whole specification and claims should be interpreted as the meaning of including rather than exclusive or exhaustive meaning; that is, it is the meaning of "including but not limited to".

[0041] Figure 1 Flow chart of the method for improving the accuracy of reservoir description based on horizontal well data according to the embodiment of the present invention. As Figure 1 shown, the present invention provides a method for improving the accuracy of reservoir description based on horizontal well data, specifically including:

[0042] Step S1: Determine the target reservoir and obtain the logging data of the target reservoir;

[0043] Step S2: Perform formation correlation and reservoir parameter interpretation on the target reservoir according to the logging data obtained in step S1, and analyze the rock-electric relationship between horizontal and vertical wells;

[0044] Step S3: Based on the flat and vertical well rock-electricity relationship obtained in Step S2, establish a horizontal well phase discrimination standard in combination with the reservoir characteristics of the target reservoir;

[0045] Step S4: Continuously describe the sedimentary microfacies of the horizontal section of the target reservoir according to the horizontal well phase discrimination standard obtained in Step S3, and construct a 3D geological model of the target reservoir;

[0046] Step S5: Establish a vertical-horizontal combined phase discrimination model based on the 3D geological model obtained in Step S4, and conduct sectional discrimination and comprehensive phase determination of the target reservoir through the vertical-horizontal combined phase discrimination model.

[0047] In practical applications, in Step S1, the logging data of the target reservoir includes vertical well logging data and horizontal well logging data, and the types of logging curves of the vertical well logging data are compatible with those of the horizontal well logging data.

[0048] In this method, in Step S2, formation correlation and reservoir parameter interpretation of the target reservoir are carried out through the obtained logging data of the target reservoir, and then the rock-electricity relationship between the flat and vertical wells is analyzed. The reservoir parameters include resistivity. In practical applications, the rock-electricity relationship between the flat and vertical wells is determined by analyzing the relationship between the resistivity of the horizontal well and the resistivity of the vertical well. The calculation formula for the rock-electricity relationship between the flat and vertical wells is:

[0049]

[0050] Among them, R a is the resistivity of the horizontal well, Ω·m; R h is the resistivity of the horizontal well, Ω·m; θ is the angle between the axis of the electrode system and the direction perpendicular to the interface, °; R m is the average resistivity of the anisotropic formation, Ω·m; λ is the resistivity anisotropy coefficient.

[0051] In addition, the calculation formula for the average resistivity of the anisotropic formation is:

[0052]

[0053] Among them, R m is the average resistivity of the anisotropic formation, Ω·m; R h is the horizontal resistivity, Ω·m; R v is the vertical resistivity, Ω·m.

[0054] In addition, the introduction of the resistivity anisotropy coefficient is to describe the degree of rock resistivity anisotropy, and its mathematical expression is:

[0055]

[0056] In the formula: R his the horizontal resistivity, Ω·m; R v is the vertical resistivity, Ω·m; R sd is the resistivity of sandstone, Ω·m; R sh is the resistivity of mudstone, Ω·m; h sd is the cumulative thickness of sandstone, m; h sh is the cumulative thickness of mudstone, m.

[0057] In practical applications, in step S3, the reservoir characteristics of the target reservoir include electrical properties, lithology, oil-bearing property, physical properties, and gas logging curves.

[0058] In this method, in step S3, the horizontal well phase discrimination criteria determine the relationship between different horizontal well microfacies types and their anisotropy coefficients. Among them, the horizontal well microfacies types include distributary channel sand bodies, sandstone sand bodies, off-formation sand bodies, and inter-distributary sand bodies; the influencing factors of the anisotropy coefficient include the resistivity of vertical wells, the resistivity of horizontal wells, and the reservoir thickness.

[0059] In practical applications, in step S4, through the obtained horizontal well phase discrimination criteria, the horizontal section sedimentary microfacies of the target reservoir can be further continuously described. By continuously describing the horizontal section sedimentary microfacies of the target reservoir, a three-dimensional geological model of the target reservoir is constructed. The three-dimensional geological model describes the relative position relationships between the horizontal well trajectories of the target reservoir and the horizons and sand bodies respectively. The three-dimensional geological model describes the relative position relationship between the horizontal well trajectory and the sand body. The types of relative position relationships between the horizontal well trajectory and the sand body include well trajectory parallel to the bedding plane, well trajectory parallel to the bedding plane without controlling the boundary, well trajectory descending within the layer, well trajectory ascending within the layer, well trajectory descending through the layer, and well trajectory ascending through the layer.

[0060] In this method, in step S5, the straight-horizontal combined phase discrimination mode is determined through the types of relative position relationships between the horizontal well trajectory and the sand body. The phase discrimination method of the straight-horizontal combined phase discrimination mode is specifically as follows:

[0061] Well trajectory parallel to the bedding plane: Controlling double boundaries, judging the phase according to the relative position between the well trajectory and the abandoned channel;

[0062] Well trajectory parallel to the bedding plane without controlling the boundary: Judging the phase according to the surrounding vertical wells or deviated wells;

[0063] Well trajectory descending within the layer: Controlling a single boundary, judging the phase according to the straight-horizontal combined phase discrimination;

[0064] Well trajectory ascending within the layer: Controlling a single boundary, judging the phase according to the straight-horizontal combined phase discrimination;

[0065] Well trajectory descending through the layer: Controlling double boundaries, the penetrated section cannot truly reflect the phase type of the current layer;

[0066] Well trajectory ascending through the layer: Controlling double boundaries, the penetrated section cannot truly reflect the phase type of the current layer.

[0067] In practical applications, large-scale distributary channels are highly interconnected and overlapping, and the internal structure of the sand bodies is complex. Using this method, the specific location of the phase change boundary can be identified, and the channel scale and reservoir connectivity relationship can be further clarified. At present, this method has been applied in the third and fourth strip blocks in the eastern transition zone of the Sabei Development Area of the Daqing Oilfield, which can effectively improve the recognition accuracy of distributary channel sand bodies and the research accuracy of remaining oil, providing a basis for improving the development effect of horizontal wells and adjusting measures in the transition zone. The working process of this method for improving reservoir description accuracy based on horizontal well data is specifically described below:

[0068] Step 1: Determine the target reservoir and obtain the logging data of the target reservoir;

[0069] Step 2: Conduct stratigraphic correlation and reservoir parameter interpretation on the target reservoir based on the obtained logging data, and analyze the litho-electric relationship between horizontal and vertical wells;

[0070] Step 3: Establish a horizontal well phase discrimination standard according to the litho-electric relationship between horizontal and vertical wells and in combination with the reservoir characteristics of the target reservoir;

[0071] Step 4: Continuously describe the sedimentary microfacies of the horizontal section of the target reservoir according to the obtained horizontal well phase discrimination standard, and construct a three-dimensional geological model of the target reservoir;

[0072] Step 5: Establish a vertical-horizontal combined phase discrimination model based on the obtained three-dimensional geological model, and conduct sectional discrimination and comprehensive phase determination on the target reservoir through the vertical-horizontal combined phase discrimination model.

[0073] In this embodiment, there are significant differences in the logging response mechanism between horizontal wells and vertical wells. By comparing the logging curve series of vertical and horizontal wells, the common curve types are clarified, the response mechanism is analyzed, the electrical property conversion relationship between horizontal wells and vertical wells is established, and at the same time, in combination with characteristics such as lithology, oil-bearing property, physical property, and gas logging, a horizontal well phase discrimination standard is established.

[0074] In practical applications, during the logging process of vertical wells, the instrument measures the horizontal resistivity parallel to the bedding plane. The logging response of horizontal wells is different from that of vertical wells. Affected by its special environment, it is mainly manifested in aspects such as spatial position, wellbore, mud invasion, and formation anisotropy. Therefore, during the analysis of horizontal well logging data, the anisotropy of formation resistivity needs to be considered.

[0075] It should be noted that given R h , R v , λ, and θ, the true resistivity R a of the horizontal formation can be calculated according to the conversion relationship. θ is the angle between the axis of the electrode system and the direction perpendicular to the interface. In this embodiment, since the formation dip angle is 2 - 3°, θ is taken as 87° this time. Since R his the horizontal resistivity, which can be regarded as the resistivity of a vertical well in actual work. By calculating the anisotropy coefficients of different sand bodies, a relationship chart between the microfacies types of horizontal wells and electrical properties is established.

[0076] Table 1 Criteria for Phase Identification of Horizontal Wells

[0077]

[0078] In this embodiment, Table 1 is the criteria for phase identification of horizontal wells. As shown in Table 1, by using data such as cuttings logging, gas logging, and logging curves, the rock-electric relationship between horizontal wells and vertical wells is established, and the anisotropy coefficients of four types of sand bodies, namely channels, sandstones, outer table, and inter-distributary, are determined. By establishing five types of relationship charts between the microfacies types of horizontal wells and electrical properties, lithology, oil-bearing properties, physical properties, and gas logging curves, the criteria for phase identification of horizontal wells are comprehensively formed.

[0079] As Figure 2 shown, during the actual drilling process of a horizontal well, its trajectory cannot be parallel to the bedding in real time, and there are situations such as upward and downward movements. By establishing a three-dimensional model, six relative position relationships between the actual drilling trajectory and the horizons and sand bodies are clarified, and different phase identification methods are used for different modes.

[0080] In this embodiment, according to the six-parameter phase identification chart of the horizontal section, the horizontal section of the horizontal well B2-6-A79 is continuously described for 10 sections of sandstone. Figure 3 This is a schematic diagram of the straight-horizontal combined three-dimensional comprehensive phase identification method for the horizontal well B2-6-A79 in the embodiment of the present invention. As Figure 3 shown, according to the three-dimensional geological model, the relative position relationship between the horizontal well trajectory and the sand body is clarified, and combined with the phase identification results of the surrounding vertical wells, the actual sedimentary microfacies of the horizontal section are comprehensively determined.

[0081] The method for improving the accuracy of reservoir description based on horizontal well data provided by the present invention can not only identify the specific location of the phase change boundary, but also further clarify the channel scale and reservoir connectivity relationship. By effectively improving the accuracy of reservoir identification, the injection-production relationship is further improved, and finally the purpose of improving the development effect is achieved, providing a basis for measure adjustment in the transition zone.

[0082] The above embodiments are only used to illustrate the present invention and are not intended to limit the present invention. Those of ordinary skill in the relevant technical fields can make various changes and modifications without departing from the spirit and scope of the present invention. Therefore, all equivalent technical solutions also belong to the scope of the present invention, and the patent protection scope of the present invention shall be defined by the claims.

Claims

1. A method for improving the accuracy of reservoir description based on horizontal well data, characterized in that, it includes: Step S1: Determine the target reservoir and obtain the logging data of the target reservoir; Step S2: Conduct stratigraphic correlation and reservoir parameter interpretation on the target reservoir according to the logging data obtained in Step S1, and analyze the rock-electric relationship between horizontal and vertical wells; Step S3: Establish a horizontal well phase discrimination standard according to the rock-electric relationship between horizontal and vertical wells obtained in Step S2, in combination with the reservoir characteristics of the target reservoir; Step S4: Continuously describe the sedimentary microfacies of the horizontal section of the target reservoir according to the horizontal well phase discrimination standard obtained in Step S3, and construct a 3D geological model of the target reservoir; Step S5: Establish a vertical-horizontal combined phase discrimination model according to the 3D geological model obtained in Step S4, and conduct sectional discrimination and comprehensive phase determination on the target reservoir through the vertical-horizontal combined phase discrimination model.

2. The method for improving the accuracy of reservoir description based on horizontal well data according to claim 1, characterized in that, in Step S1, the logging data of the target reservoir includes vertical well logging data and horizontal well logging data, and the types of logging curves of the vertical well logging data are compatible with those of the horizontal well logging data.

3. The method for improving the accuracy of reservoir description based on horizontal well data according to claim 1, characterized in that, in Step S2, the reservoir parameters include resistivity, and the rock-electric relationship between horizontal and vertical wells is determined by analyzing the relationship between the resistivity of the horizontal well and the resistivity of the vertical well. The calculation formula for the rock-electric relationship between horizontal and vertical wells is: where, R a is the resistivity of the horizontal well, Ω·m; R h is the resistivity of the horizontal well, Ω·m; θ is the angle between the axis of the logging sonde and the direction of the vertical interface, °; R m is the average resistivity of the anisotropic formation, Ω·m; λ is the resistivity anisotropy coefficient.

4. The method for improving the accuracy of reservoir description based on horizontal well data according to claim 1, characterized in that, the calculation formula for the average resistivity of the anisotropic formation is: where R m is the average resistivity of the anisotropic formation, Ω·m; R h is the horizontal resistivity, Ω·m; R v is the vertical resistivity, Ω·m.

5. The method for improving the accuracy of reservoir description based on horizontal well data according to claim 4, characterized in that, the introduction of the resistivity anisotropy coefficient is to describe the degree of rock resistivity anisotropy, and its mathematical expression is: Where: R h is the horizontal resistivity, Ω·m; R v is the vertical resistivity, Ω·m; R sd is the resistivity of sandstone, Ω·m; R sh is the resistivity of mudstone, Ω·m; h sd is the cumulative thickness of sandstone, m; h sh is the cumulative thickness of mudstone, m.

6. The method for improving the accuracy of reservoir description based on horizontal well data according to claim 1, characterized in that, in Step S3, the reservoir characteristics of the target reservoir include electric property, lithology, oil-bearing property, physical property and gas logging curve.

7. The method for improving the accuracy of reservoir description based on horizontal well data according to claim 1, characterized in that, in Step S3, the horizontal well phase discrimination standard determines the relationship between different horizontal well microfacies types and their anisotropy coefficients. The horizontal well microfacies types include distributary channel sand bodies, sandstone sand bodies, off-formation sand bodies and inter-distributary sand bodies. The influencing factors of the anisotropy coefficient include the resistivity of the vertical well, the resistivity of the horizontal well and the reservoir thickness.

8. The method for improving the accuracy of reservoir description based on horizontal well data according to claim 1, characterized in that, In the step S4, the 3D geological model describes the relative positional relationships between the horizontal well trajectories of the target reservoir and the horizons and sand bodies respectively. The types of relative positional relationships between the horizontal well trajectories and the sand bodies include well trajectory parallel to the bedding plane, well trajectory parallel to the bedding plane without controlling the boundary, well trajectory descending within the layer, well trajectory ascending within the layer, well trajectory descending through the layer, and well trajectory ascending through the layer.

9. The method for improving the reservoir description accuracy based on horizontal well data according to claim 8, characterized in that in the step S5, a straight-flat combined phase discrimination mode is determined through the types of relative positional relationships between the horizontal well trajectories and the sand bodies. The phase discrimination method of the straight-flat combined phase discrimination mode is specifically as follows: Well trajectory parallel to the bedding plane: controlling double boundaries, and discriminating the phase according to the relative position between the well trajectory and the abandoned channel; Well trajectory parallel to the bedding plane without controlling the boundary: discriminating the phase according to the surrounding vertical wells or deviated wells; Well trajectory descending within the layer: controlling a single boundary, and discriminating the phase according to the straight-flat combination; Well trajectory ascending within the layer: controlling a single boundary, and discriminating the phase according to the straight-flat combination; Well trajectory descending through the layer: controlling double boundaries, and the penetrated layer section cannot truly reflect the phase type of the current layer; Well trajectory ascending through the layer: controlling double boundaries, and the penetrated layer section cannot truly reflect the phase type of the current layer.

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