Sandstone reservoir oil-water layer logging identification method and system

Abstract

The invention provides a sandstone reservoir oil-water layer logging identification method and system, and belongs to the field of reservoir evaluation. According to the method, an identification plate is obtained according to oil testing and production testing data and gas logging data, and then the fluid type of a reservoir to be identified is identified through the identification plate. According to the method, a conventional gas logging technology is adopted, new technical means and measurement time do not need to be added, the fluid type of the sandstone reservoir can be simply, conveniently and rapidly recognized based on deep excavation of gas logging data, the recognition coincidence rate is increased, a basis is provided for exploration and development decision and benefit development, and the method has the advantages of being economical, real-time, accurate and the like and has good application prospects. The popularization and application prospects are wide.

Description

Technical Field

[0001] This invention belongs to the field of reservoir evaluation, specifically relating to a method and system for identifying oil and water layers in sandstone reservoirs through logging. Background Technology

[0002] Rapid and accurate identification of oil and water layers during drilling is crucial for developing fracturing strategies. Gas logging data, which is recorded in real time during drilling, provides direct information reflecting the hydrocarbon-bearing properties of underground reservoirs and plays an important role in the interpretation and identification of oil and water layers.

[0003] Currently, oil-water identification using gas logging data is mainly determined through differences in gas logging curve amplitude, component distribution curves, triangular plots, and radar chart patterns. However, because gas logging path data is influenced by many drilling factors (such as drilling speed, displacement, and drill bit diameter), these methods are highly regional, have a high misjudgment rate, and, due to the lack of quantitative evaluation parameters, the evaluation results are somewhat subjective, hindering standardized and widespread application.

[0004] To address the current problems of low data mining efficiency, low oil-water identification accuracy, and strong subjectivity in gas logging, a new logging method for identifying oil and water layers in sandstone reservoirs is urgently needed. Summary of the Invention

[0005] The purpose of this invention is to solve the problems existing in the prior art and provide a method and system for identifying oil and water layers in sandstone reservoirs through logging. Based on the ratio of conventional gas logging components, it avoids the influence of drilling factors on absolute quantities. From the perspective of simple and quick identification of oil and water layers, it does not require the addition of new methods and measurement time. Based on the differences in different fluid components, it establishes a method for identifying fluid types in sandstone reservoirs, improves the fluid interpretation accuracy and regional adaptability, and provides a basis for exploration and development decisions and profitable development.

[0006] This invention is achieved through the following technical solution:

[0007] In a first aspect, the present invention provides a method for identifying oil-water layers in sandstone reservoirs by logging, wherein the method obtains an identification chart based on oil testing and production data and gas logging data, and then uses the identification chart to identify the fluid type of the reservoir to be identified.

[0008] Preferably, the method includes the following steps:

[0009] (1) Collect oil testing and production data and gas logging data from n wells;

[0010] (2) Obtain gas logging data for different fluid types at different depths, and then calculate the radar chart parameters.

[0011] (3) Based on the radar chart parameters, draw radar charts for each depth point within the depth segment corresponding to each fluid type;

[0012] (4) Obtain the first and second areas of each radar image;

[0013] (5) Draw an identification board based on the first and second areas;

[0014] (6) Use identification charts to identify the fluid type of the reservoir to be identified.

[0015] Preferably, the oil testing and production data includes: depth range and the fluid type corresponding to the depth range;

[0016] The fluid types include: oil layer, water layer, oil-water co-layer, and oil-water layer;

[0017] The gas logging data includes: methane content (C1), ethane content (C2), propane content (C3), isobutane content (iC4), and n-butane content (nC4).

[0018] Preferably, the operation of obtaining gas logging data for different fluid types at corresponding depths in step (2) includes:

[0019] For the different fluid types and depth ranges in the oil testing and production data, the following operations are performed: the gas logging data within each depth range is read out one by one.

[0020] Preferably, the operation of calculating and obtaining radar image parameters in step (2) includes:

[0021] The values ​​of C1 / C2, C1 / C3, C2 / C3, C3 / iC4, C3 / nC4, and iC4 / nC4 are calculated respectively to obtain 6 radar chart parameters.

[0022] Preferably, in step (3), the six coordinate axes in the radar chart correspond to six radar chart parameters, and each solid dot represents the value of a radar chart parameter.

[0023] On the radar chart, the coordinate axes are C1 / C2, C1 / C3, C2 / C3, C3 / iC4, C3 / nC4, and iC4 / nC4 in a clockwise direction.

[0024] Preferably, step (4) includes the following operations:

[0025] Perform the following operations for each radar chart:

[0026] Connect the solid points on the coordinate axes corresponding to C2 / C3, C3 / iC4, and C3 / nC4 in the radar chart to form the first maximum polyline. Sort C2 / C3, C3 / iC4, and C3 / nC4, find the minimum value among them as the first minimum value, and draw the first minimum value on the coordinate axis corresponding to the radar chart parameter that is greater than the first minimum value. Then connect the first minimum values ​​on the three coordinate axes to form the first minimum polyline. Finally, calculate the area of ​​the region enclosed by the first maximum polyline, the first minimum polyline, and coordinate axes C2 / C3 and C3 / nC4, and take it as the first area A1.

[0027] Connect the solid points on the coordinate axes corresponding to C2 / C3, C1 / C3, and C1 / C2 in the radar chart to form the second maximum polyline. Sort C2 / C3, C1 / C3, and C1 / C2, find the minimum value among them as the second minimum value, and draw the second minimum value on the coordinate axis corresponding to the radar chart parameter that is greater than the second minimum value. Then connect the second minimum values ​​on the three coordinate axes to form the second minimum polyline. Finally, calculate the area of ​​the region enclosed by the second maximum polyline, the second minimum polyline, and the coordinate axes C2 / C3 and C1 / C2, and take it as the second area A2.

[0028] Preferably, step (5) includes:

[0029] Using the first area A1 and the second area A2 as the horizontal and vertical axes of the coordinate graph, respectively, the intersection points of the first area A1 and the second area A2 of all radar images are plotted on the coordinate graph to obtain the identification chart; each fluid type has a corresponding area in the identification chart.

[0030] Preferably, step (6) includes:

[0031] First, the radar map parameters are calculated using gas logging data at all depth points in the reservoir to be identified. Then, the radar map is obtained according to step (3). Then, the first area A1 and the second area A2 are obtained according to step (4). Then, the first area A1 and the second area A2 are projected onto the identification map to obtain multiple points to be identified. Finally, the fluid type of the reservoir to be identified is determined according to the area where the points to be identified are located.

[0032] Preferably, the operation of determining the fluid type of the reservoir to be identified based on the region where the points to be identified are located includes: finding the region where most of the points to be identified are located, and the fluid type corresponding to the region is the fluid type of the reservoir to be identified;

[0033] "Most" refers to 70% or more.

[0034] A second aspect of the present invention provides a sandstone reservoir oil-water layer logging identification system, the system comprising:

[0035] The data acquisition module is used to collect oil testing and production data and gas logging data from n wells;

[0036] The radar chart parameter acquisition module is connected to the data acquisition module and is used to obtain gas logging data at different depths for different fluid types, and then calculate the radar chart parameters.

[0037] The radar chart drawing module, connected to the radar chart parameter acquisition module, is used to draw radar charts for each depth point within the depth segment corresponding to each fluid type based on the radar chart parameters.

[0038] The area acquisition module, connected to the radar rendering module, is used to acquire the first and second areas of each radar image.

[0039] The recognition pattern drawing module is connected to the area acquisition module and is used to draw the recognition pattern based on the first area and the second area.

[0040] The identification module is connected to the radar chart parameter acquisition module, radar chart drawing module, area acquisition module, and identification chart drawing module, respectively, and is used to identify the fluid type of the reservoir to be identified using the identification chart.

[0041] Compared with existing technologies, the beneficial effects of this invention are: this invention adopts conventional gas logging technology, without the need to add new technical means and measurement time; based on in-depth mining of gas logging data, this invention can easily and quickly identify the fluid type of sandstone reservoirs, improve the identification accuracy, provide a basis for exploration and development decisions and profitable development, and has the characteristics of being economical, real-time, and accurate, with broad prospects for promotion and application. Attached Figure Description

[0042] Figure 1-1 This is a radar image of a sandstone aquifer in a certain area, where the area of ​​the dark shaded region is A1 and the area of ​​the light shaded region is A2.

[0043] Figure 1-2 This is a radar image of an oil-bearing sandstone layer in a certain area, where the area of ​​the dark shaded region is A1 and the area of ​​the light shaded region is A2.

[0044] Figure 1-3 This is a radar image of a sandstone oil layer in a certain area, where the area of ​​the dark shaded region is A1 and the area of ​​the light shaded region is A2.

[0045] Figure 2 This is an oil-water identification chart for a certain work area established using the method of the present invention;

[0046] Figure 3 The fluid identification results of the X1 section of a sandstone-mudstone well obtained using the method of the present invention;

[0047] Figure 4 This is a flowchart illustrating the steps of the method of the present invention. Detailed Implementation

[0048] The present invention will now be described in further detail with reference to the accompanying drawings:

[0049] This invention provides a method for identifying oil and water layers in sandstone reservoirs through logging. Compared with existing technologies, this invention is based on in-depth analysis of gas logging data, which enables convenient and accurate identification of oil and water layers in sandstone reservoirs.

[0050] The method of the present invention obtains an identification chart based on oil testing and production data and gas logging data, and then uses the identification chart to identify the fluid type of the reservoir to be identified.

[0051] Specifically, such as Figure 4 As shown, the method includes the following steps:

[0052] (1) Data Acquisition: Collect oil testing and production data and gas logging data from n wells (n≥1) in a certain area. The oil testing and production data includes: depth range and the corresponding fluid type. The fluid type includes: oil layer, water layer, oil-water co-layer, oil-water layer, etc. These data are generally included in the oil testing and production data. The gas logging data includes: C1, C2, C3, iC4, nC4, which represent the contents of methane, ethane, propane, isobutane, and n-butane, respectively. The unit is generally %, which usually refers to molar content. These data are all measured using existing instruments.

[0053] (2) Obtain radar chart parameters: Obtain gas logging data for different fluid types at different depths, and then calculate and obtain radar chart parameters.

[0054] The operation of obtaining gas logging data at different depths corresponding to different fluid types includes:

[0055] For the different fluid types and depth ranges in the oil testing and production data, the following operations are performed: the gas logging data within the depth range is read out point by point (i.e., read point by point), and each depth point corresponds to a set of data values ​​(including: C1, C2, C3, iC4, nC4 values).

[0056] The operations for calculating and obtaining radar image parameters include:

[0057] The values ​​of C1 / C2, C1 / C3, C2 / C3, C3 / iC4, C3 / nC4, and iC4 / nC4 are calculated respectively to obtain 6 radar chart parameters.

[0058] For identification to be performed, at least two types of fluids are required. Therefore, there are at least two different fluid types, such as oil layer, oil-water co-layer, oil-water layer, and water layer.

[0059] (3) Draw radar charts: Based on the 6 radar chart parameters calculated in step (2), draw radar charts for each depth point within the depth segment corresponding to each fluid type (one depth point corresponds to a set of data, including the values ​​of C1, C2, C3, iC4, and nC4, and the above 6 radar chart parameters are calculated accordingly). (Drawing radar charts is a basic operation in the industry and can be done with the help of software, such as Excel, Origin, etc.). The 6 coordinate axes in the radar chart correspond to the above 6 radar chart parameters, and each solid dot represents the value of a radar chart parameter. One depth point corresponds to one radar chart; the 6 coordinate axes in each radar chart use a uniform linear scale. The scale principle is that the minimum and maximum values ​​can be reasonably displayed, that is, the scale can reasonably cover the maximum and minimum values ​​of the 6 radar chart parameters. In addition, the graph should be a hexagon that is not excessively concave (if it is excessively concave, the minimum value of the scale can be adjusted to be smaller). Preferably, on the radar chart, the coordinate axes are C1 / C2, C1 / C3, C2 / C3, C3 / iC4, C3 / nC4, and iC4 / nC4 in a clockwise direction.

[0060] (4) Obtain the first and second areas of each radar image:

[0061] Perform the following operations for each radar chart:

[0062] Connect the solid points on the coordinate axes corresponding to C2 / C3, C3 / iC4, and C3 / nC4 in the radar chart to form the first maximum polyline. Sort C2 / C3, C3 / iC4, and C3 / nC4, find the minimum value among them as the first minimum value, and plot the first minimum value on the coordinate axes corresponding to radar chart parameters greater than the first minimum value. Then connect the first minimum values ​​on the three coordinate axes to form the first minimum polyline. Finally, calculate the area of ​​the region enclosed by the first maximum polyline, the first minimum polyline, and coordinate axes C2 / C3 and C3 / nC4, and use this area as the first area A1 (this area can be obtained by simply adding or subtracting the areas of triangles, trapezoids, etc.). For example... Figure 1-1 Among C2 / C3, C3 / iC4, and C3 / nC4, the values ​​of C2 / C3 and C3 / nC4 are equal and less than the value of C3 / iC4. Therefore, the values ​​of C2 / C3 and C3 / nC4 are the first minimum values. The first minimum value is plotted on the coordinate axis corresponding to C3 / iC4. Then, the three first minimum values ​​are connected sequentially to form the first minimum polyline. The region enclosed by the first maximum polyline, the first minimum polyline, and the coordinate axes C2 / C3 and C3 / nC4 includes two triangles. The sum of the areas of these two triangles is the first area A1. Figure 1-1 The dark shaded area is shown in the image.

[0063] Similarly, connect the solid points on the coordinate axes corresponding to C2 / C3, C1 / C3, and C1 / C2 in the radar chart to form the second maximum polyline; sort C2 / C3, C1 / C3, and C1 / C2, find the minimum value among them as the second minimum value, and plot the second minimum value on the coordinate axis corresponding to the parameter greater than the second minimum value. Then connect the second minimum values ​​on the three coordinate axes to form the second minimum polyline. Finally, calculate the area of ​​the region enclosed by the second maximum polyline, the second minimum polyline, and coordinate axes C2 / C3 and C1 / C2, and use this as the first area A2 (this area can be obtained by simply adding or subtracting the areas of triangles, trapezoids, etc.). For example... Figure 1-1 Among C2 / C3, C1 / C3, and C1 / C2, C2 / C3 has the smallest value, so it is taken as the second minimum value. The second minimum value is plotted on the coordinate axes corresponding to C1 / C3 and C1 / C2. Then, the three second minimum values ​​are connected sequentially to form a second minimum polyline. The region enclosed by the second maximum polyline, the second minimum polyline, and the coordinate axes C2 / C3 and C1 / C2 includes two triangles and a trapezoid. The sum of the areas of these two triangles and the trapezoid is the second area A2. Figure 1-1 The light-shaded area is shown in the image.

[0064] As can be seen, one radar image corresponds to one depth point, and one radar image corresponds to a first area A1 and a second area A2.

[0065] (5) Draw an identification board based on the first and second areas:

[0066] Using the first area A1 and the second area A2 as the x and y axes of a coordinate graph, respectively, the intersection points of all radar images with the first area A1 and the second area A2 are plotted on the coordinate graph to obtain an identification chart. Each fluid type has a corresponding area in the identification chart. For example... Figure 2 As shown (for ease of description, in) Figure 2 Vertical and horizontal lines were drawn in the middle. Figure 2 As can be seen, the first area A1 of the oil layer is concentrated to the right of the vertical line, meaning the area to the right of the vertical line is the oil layer region; the first area A1 of the oil-bearing water layer is concentrated to the left of the vertical line, and the second area A2 is concentrated above the horizontal line, meaning the area to the left of the vertical line and above the horizontal line is the water layer region; the first area A1 of the water layer is concentrated to the left of the vertical line, and the second area A2 is concentrated below the horizontal line, meaning the area to the left of the vertical line and below the horizontal line is the water layer region. Thus, the fluid type can be identified using this identification chart. The data in this embodiment shows the characteristics of vertical and horizontal lines. In other embodiments, diagonal lines or more or fewer lines may appear. These lines are only added to the identification chart for descriptive convenience and are not actually present in the generated identification chart.

[0067] (6) Identify the fluid type of the reservoir to be identified using an identification chart:

[0068] For the reservoir whose fluid type is to be identified (i.e., the reservoir to be identified), firstly, the radar chart parameters are calculated using gas logging data at all depth points in the reservoir to be identified. Then, the radar chart is obtained using the same method as in step (3). Next, the first area A1 and the second area A2 are obtained using the same method as in step (4). Then, the first area A1 and the second area A2 are plotted on the identification chart. That is, multiple points to be identified are drawn on the identification chart based on the calculated first area A1 and the second area A2 (each point to be identified corresponds to the intersection of the first area A1 and the second area A2 of a radar chart). The fluid type of the reservoir is determined based on the area where most of the points to be identified (set according to the actual situation, for example, it can be 70%) are located. For example, if 70% of the points to be identified are located on the right side of the vertical line (i.e., the oil layer area), then the fluid type of the reservoir to be identified is determined to be an oil layer.

[0069] The embodiments of the method of the present invention are as follows:

[0070] Example 1:

[0071] (1) Collect oil testing and production data and gas logging data from two wells in a certain area;

[0072] (2) Based on the oil test and production results, gas logging data of the three types of fluids at corresponding depths of oil layer, oil-bearing water layer and water layer were obtained. The values ​​of C1 / C2, C1 / C3, C2 / C3, C3 / iC4, C3 / nC4 and iC4 / nC4 were calculated respectively to obtain 6 radar chart parameters;

[0073] (3) Based on the six radar image parameters calculated in step (2), radar images of the oil layer, oil-bearing water layer, and water layer are drawn at each depth point, as follows: Figures 1-1 to 1-3 As shown, each radar chart uses a linear scale with a scale range of [-10, 50].

[0074] (4) Calculate the first area A1 and the second area A2 in the radar charts corresponding to the three types of fluids respectively; Figure 1-1 In the diagram, the first area A1 is 147.6, and the second area A2 is 212.1. Figure 1-2 In the diagram, the first area A1 is 139.1, and the second area A2 is 387.5. Figure 1-3 In the diagram, the first area A1 is 180.4, and the second area A2 is 549.5.

[0075] (5) Using the first area A1 and the second area A2 calculated for the corresponding depth segments of the oil layer, oil-bearing water layer, and water layer as the abscissa and ordinate respectively, an identification chart is drawn, such as... Figure 2 As shown, from Figure 2 It can be seen that the oil layer region is: A1≥172; the oil-bearing water layer region is: A2≥345 and A1<172; the water layer region is: A1<172 and A2<345.

[0076] (6) For a certain well in this area, X1 sandstone and mudstone reservoir (depth of 3808-3828m), the corresponding gas logging data is read at each sampling point in this depth range and 30 radar charts are drawn (because there is a sampling point of 1m in this depth range, there are 30 C1 to C4 data points in total, so there are 30 radar charts). Using the same [-10, 50] linear scale as in step (3), the first area A1 and the second area A2 in the 30 radar charts are calculated.

[0077] (7) Project the obtained 30 points with the first area A1 and the second area A2 onto the recognition map established in step (5) to obtain the points to be recognized, such as Figure 3 As shown, from Figure 3 As can be seen, all the points to be identified fall within the oil layer region, therefore layer X1 is determined to be an oil layer.

[0078] The present invention also provides a sandstone reservoir oil-water layer logging identification system, and an embodiment of the system is as follows:

[0079] Example 2:

[0080] The system includes:

[0081] The data acquisition module is used to collect oil testing and production data and gas logging data from n wells;

[0082] The radar chart parameter acquisition module is connected to the data acquisition module and is used to obtain gas logging data at different depths for different fluid types, and then calculate the radar chart parameters.

[0083] The radar chart drawing module, connected to the radar chart parameter acquisition module, is used to draw radar charts for each depth point within the depth segment corresponding to each fluid type based on the radar chart parameters.

[0084] The area acquisition module, connected to the radar rendering module, is used to acquire the first and second areas of each radar image.

[0085] The recognition pattern drawing module is connected to the area acquisition module and is used to draw the recognition pattern based on the first area and the second area.

[0086] The identification module is connected to the radar chart parameter acquisition module, radar chart drawing module, area acquisition module, and identification chart drawing module, respectively, and is used to identify the fluid type of the reservoir to be identified using the identification chart.

[0087] The above technical solution is only one embodiment of the present invention. For those skilled in the art, based on the principles disclosed in the present invention, it is easy to make various types of improvements or modifications, and not limited to the technical solutions described in the specific embodiments of the present invention. Therefore, the foregoing description is only a preferred option and is not restrictive.

Claims

1. A method for identifying oil-water layers in sandstone reservoirs through well logging, characterized in that: The method obtains an identification chart based on oil testing and production data and gas logging data, and then uses the identification chart to identify the fluid type of the reservoir to be identified.

2. The method for identifying oil and water layers in sandstone reservoirs according to claim 1, characterized in that: The method includes the following steps: (1) Collect oil testing and production data and gas logging data from n wells; (2) Obtain gas logging data for different fluid types at different depths, and then calculate the radar chart parameters; (3) Based on the radar chart parameters, draw radar charts for each depth point within the depth segment corresponding to each fluid type; (4) Obtain the first and second areas of each radar image; (5) Draw an identification board based on the first and second areas; (6) Use identification charts to identify the fluid type of the reservoir to be identified.

3. The method for identifying oil and water layers in sandstone reservoirs according to claim 2, characterized in that: The oil testing and production data includes: depth range and the fluid type corresponding to the depth range; The fluid types include: oil layer, water layer, oil-water co-layer, and oil-water layer; The gas logging data includes: methane content (C1), ethane content (C2), propane content (C3), isobutane content (iC4), and n-butane content (nC4).

4. The method for identifying oil and water layers in sandstone reservoirs according to claim 3, characterized in that: The operation of obtaining gas logging data for different fluid types at corresponding depths in step (2) includes: For the different fluid types and depth ranges in the oil testing and production data, the following operations are performed: the gas logging data within each depth range is read out one by one.

5. The method for identifying oil and water layers in sandstone reservoirs according to claim 3, characterized in that: The operations in step (2) to calculate and obtain the radar image parameters include: The values ​​of C1 / C2, C1 / C3, C2 / C3, C3 / iC4, C3 / nC4, and iC4 / nC4 are calculated respectively to obtain 6 radar chart parameters.

6. The method for identifying oil and water layers in sandstone reservoirs according to claim 5, characterized in that: In step (3), the six coordinate axes in the radar chart correspond to six radar chart parameters, and each solid dot represents the value of a radar chart parameter. On the radar chart, the coordinate axes are C1 / C2, C1 / C3, C2 / C3, C3 / iC4, C3 / nC4, and iC4 / nC4 in a clockwise direction.

7. The method for identifying oil and water layers in sandstone reservoirs according to claim 6, characterized in that: Step (4) includes the following operations: Perform the following operations for each radar chart: Connect the solid points on the coordinate axes corresponding to C2 / C3, C3 / iC4, and C3 / nC4 in the radar chart to form the first maximum polyline. Sort C2 / C3, C3 / iC4, and C3 / nC4, find the minimum value among them as the first minimum value, and draw the first minimum value on the coordinate axis corresponding to the radar chart parameter that is greater than the first minimum value. Then connect the first minimum values ​​on the three coordinate axes to form the first minimum polyline. Finally, calculate the area of ​​the region enclosed by the first maximum polyline, the first minimum polyline, and coordinate axes C2 / C3 and C3 / nC4, and take it as the first area A1. Connect the solid points on the coordinate axes corresponding to C2 / C3, C1 / C3, and C1 / C2 in the radar chart to form the second maximum polyline. Sort C2 / C3, C1 / C3, and C1 / C2, find the minimum value among them as the second minimum value, and draw the second minimum value on the coordinate axis corresponding to the radar chart parameter that is greater than the second minimum value. Then connect the second minimum values ​​on the three coordinate axes to form the second minimum polyline. Finally, calculate the area of ​​the region enclosed by the second maximum polyline, the second minimum polyline, and the coordinate axes C2 / C3 and C1 / C2, and take it as the second area A2.

8. The method for identifying oil and water layers in sandstone reservoirs according to claim 7, characterized in that: Step (5) includes the following operations: Using the first area A1 and the second area A2 as the horizontal and vertical axes of the coordinate graph, respectively, the intersection points of the first area A1 and the second area A2 of all radar images are plotted on the coordinate graph to obtain the identification chart; each fluid type has a corresponding area in the identification chart.

9. The method for identifying oil and water layers in sandstone reservoirs according to claim 8, characterized in that: Step (6) includes the following operations: First, the radar map parameters are calculated using gas logging data at all depth points in the reservoir to be identified. Then, the radar map is obtained according to step (3). Then, the first area A1 and the second area A2 are obtained according to step (4). Then, the first area A1 and the second area A2 are projected onto the identification map to obtain multiple points to be identified. Finally, the fluid type of the reservoir to be identified is determined according to the area where the points to be identified are located.

10. The method for identifying oil and water layers in sandstone reservoirs according to claim 9, characterized in that: The operation of determining the fluid type of the reservoir to be identified based on the region where the points to be identified are located includes: finding the region where most of the points to be identified are located, and the fluid type corresponding to the region is the fluid type of the reservoir to be identified; "Most" refers to 70% or more.

11. A sandstone reservoir oil-water layer logging identification system, characterized in that: The system includes: The data acquisition module is used to collect oil testing and production data and gas logging data from n wells; The radar chart parameter acquisition module is connected to the data acquisition module and is used to obtain gas logging data for different fluid types at different depths, and then calculate the radar chart parameters. The radar chart drawing module, connected to the radar chart parameter acquisition module, is used to draw radar charts for each depth point within the depth segment corresponding to each fluid type based on the radar chart parameters. The area acquisition module, connected to the radar rendering module, is used to acquire the first and second areas of each radar image. The recognition pattern drawing module is connected to the area acquisition module and is used to draw the recognition pattern based on the first area and the second area. The identification module is connected to the radar chart parameter acquisition module, radar chart drawing module, area acquisition module, and identification chart drawing module, respectively, and is used to identify the fluid type of the reservoir to be identified using the identification chart.

Images