A method for describing distribution of only interlayer water and interlayer water compact gas reservoir advantage area

Abstract

The application discloses a distribution description method for only containing in-layer water and interlayer water dense gas reservoir advantage area, belongs to the field of tapping potential of old oil and gas field development area, and specifically comprises the following steps: collecting and arranging dynamic parameters and static parameters of a dense gas reservoir of a target block; selecting one piece of a dense sandstone reservoir core with different permeabilities in a single well, and obtaining movable water partition saturation thereof; calculating single-well remaining geological reserve abundance; drawing a block well site distribution map, and respectively interpolating single-well remaining geological reserve abundance and single-well water saturation; obtaining a movable water partition map; and finally determining a dense gas reservoir advantage area. The application combines dynamic and static data, is in line with the reality, has high accuracy, and is convenient and efficient to obtain an advantage area identification map, intuitively understands the advantage area, has wide application range, and has strong popularization.

Description

Technical Field

[0001] This invention belongs to the field of tapping the potential of old oil and gas field development, specifically involving a method for describing the distribution of advantageous areas of tight gas reservoirs containing only intra-layer water and inter-layer water. Background Technology

[0002] Tight sandstone gas reservoirs are characterized by low porosity and permeability, complex pore-throat structures with micro- to nanometer-sized pores and throats, and high water saturation, making their development difficult and resulting in low recovery rates. Furthermore, the flow within the reservoir is predominantly gas-water two-phase, and water production from gas wells severely inhibits single-well productivity, shortens well production cycles, and can even lead to premature well failure. Therefore, during gas well production, it is essential to extend the waterless production period of tight sandstone gas wells as much as possible.

[0003] The primary condition for extending the waterless production period of tight gas reservoirs is to identify the reservoir's dominant areas and prioritize well placement within these areas to ensure the waterless production period. For edge and bottom water reservoirs, water intrusion characteristic description methods make it relatively easy to determine the water body boundaries and shapes. Therefore, the dominant areas of edge and bottom water reservoirs are mainly determined by the abundance of remaining geological reserves, making the process relatively simple. However, for tight gas reservoirs containing only intra-layer and inter-layer water, water intrusion characteristic description methods are not applicable, and the water body boundaries and shapes are difficult to determine. Consequently, the dominant areas of tight gas reservoirs containing only intra-layer and inter-layer water are difficult to identify, necessitating an effective method for determining the distribution of dominant areas in such reservoirs.

[0004] Extensive research has revealed a scarcity of methods for describing the distribution of dominant areas in tight gas reservoirs containing only intra- and inter-layer water. Existing methods for describing movable water largely rely on establishing geological models to study reservoir water distribution, which is complex, requires high model accuracy, and is often not integrated with the dynamic production of individual gas wells. For example, patent application CN104183018A, entitled "A Six-Stage Modeling Method for Characterizing Gas-Water Distribution in Water-Bearing Carbonate Gas Reservoirs," discloses a method for studying movable water distribution using numerical simulation, but the specific process is quite complex. Another example is patent application CN112727452A, entitled "A Method for Describing Movable Water Distribution in Tight Sandstone Gas Reservoirs," which discloses a technique for gas-water zoning based on formation water salinity data and single-well water production type. However, formation water salinity is easily affected by construction conditions, leading to measurement errors and inaccurate results. Furthermore, it requires separate measured formation water data, resulting in high costs and long development cycles.

[0005] In conclusion, there is an urgent need for a highly accurate, practical method to describe the distribution of advantageous areas in tight gas reservoirs that aligns with actual conditions, thus providing a guarantee for subsequent gas reservoir development and potential tapping for increased production. Summary of the Invention

[0006] The purpose of this invention is to solve the problems of complex procedures, high costs, and large errors in current methods for describing the distribution of advantageous areas of tight gas reservoirs. By combining stratigraphic characteristics and single-well production data, this invention describes the distribution of advantageous areas of tight gas reservoirs containing only intra- and inter-layer water, which is low-cost, highly operable, efficient, and convenient.

[0007] The objective of this invention is achieved through the following technical solution: A method for describing the distribution of dominant areas in tight gas reservoirs containing only intra-layer and inter-layer water includes the following steps: S1. Collect and organize the dynamic and static parameters of the tight gas reservoir in the target block; S2. Based on the data collected in step S1, select one core sample each from the high-permeability, medium-permeability, and low-permeability tight sandstone reservoirs of a single well, and obtain the saturation of the movable water zones of the three tight sandstone reservoir core samples. S3. Calculate the abundance of remaining geological reserves in a single well; S4. Draw a well location distribution map of the block using the carry coordinates and block boundary coordinates, and interpolate the remaining geological reserves abundance and water saturation of a single well using the well location distribution map. S5. Compare the saturation value of the movable water zone obtained in step S2 with the water saturation value obtained in step S4: When the water saturation value is lower than the saturation of the movable water zone, the block is a low movable water zone; When the water saturation value is equal to or higher than the saturation value of the movable water zone, the area is a high movable water zone. The water saturation distribution map of the block is divided into zones to obtain a movable water zone map; S6. Overlay the remaining geological reserve abundance distribution map of the block with the movable water zoning map of step S5 to obtain the dominant area identification map, and determine the intersection of the low movable water area and the area with remaining geological reserve abundance greater than the preset value as the tight gas reservoir dominant area.

[0008] Furthermore, in step S1, the dynamic parameters include the cumulative production Q of a single well.

[0009] Furthermore, in step S1, the static parameters include reservoir thickness h, single-well permeability K, single-well porosity Φ, single-well water saturation Sw, well location coordinates, and block boundary coordinates.

[0010] Furthermore, in step S2, the saturation of the movable water zone in the tight sandstone reservoir core is obtained through centrifugal nuclear magnetic resonance experiments and gas-water phase permeation experiments. The method for obtaining the saturation of the movable water zone includes the following steps: I. Determine the block with a single - well permeability range of K > 1 mD as the high - permeability zone, the block with a permeability range of 0.3 mD < K < 1 mD as the medium - permeability zone, and the block with a permeability range of 0.01 mD < K < 0.3 mD as the low - permeability zone; II. Place three cores with different permeabilities under saturated - water conditions and measure the nuclear magnetic T2 values of the three cores under saturated - water conditions; III. Conduct a centrifugal nuclear magnetic experiment on the three cores to obtain the irreducible water saturations corresponding to different displacement pressures of the three cores, and obtain the relationship curve between the fluid mobility efficiency and the displacement pressure of the three cores; IV. Determine the optimal displacement pressure through the relationship curve between the fluid mobility efficiency and the displacement pressure of the three cores, and take the average value of the irreducible water saturations corresponding to the optimal displacement pressures of the three cores to obtain the reservoir average irreducible water saturation I; V. Conduct a gas - water relative permeability experiment on the three cores to obtain the gas - water relative permeability curve, obtain the irreducible water saturations of the three cores through the gas - water relative permeability curve, and then take the average value of the irreducible water saturations of the three cores to obtain the reservoir average irreducible water saturation II; VI. Take the average value of the reservoir average irreducible water saturation I obtained in step IV and the reservoir average irreducible water saturation II obtained in step V to obtain the movable water - zone saturation.

[0011] Further, in step III, the corresponding formula between the centrifugal speed and the displacement pressure is P = lρ w Rn 2 π 2 / 900, l is the core length, and the standard core length is 2.54 cm, ρ w is the water density, R is the centrifugal radius, n is the centrifugal speed, P is the displacement pressure, π is the pi.

[0012] Further, in step S3, the calculation method of the single - well remaining geological reserve abundance is as follows: Obtain the single - well controlled area A, obtain the single - well geological reserve G, and calculate the single - well remaining geological reserve abundance value Ω through the single - well remaining geological reserve abundance calculation formula Ω=(G - Q) / A.

[0013] Further, the single - well controlled area A is calculated by the area weighing method, and the single - well geological reserve G is calculated by the volume method.

[0014] Furthermore, in step S4, the abundance of remaining geological reserves in a single well is interpolated using Gaussian simulation in the Kriging interpolation method to obtain a distribution map of the abundance of remaining geological reserves in the block; the water saturation of a single well is interpolated using Gaussian simulation in the Kriging interpolation method to obtain a distribution map of the water saturation in the block.

[0015] Furthermore, in step S6, the low-mobility water zone and the remaining geological reserves abundance greater than 0.2Ω are considered. max The intersection of the regions was identified as the dominant area for tight gas reservoirs, where Ω max This represents the maximum abundance of remaining geological reserves in a single well.

[0016] Furthermore, in step S1, the static parameters are obtained through well logging interpretation methods.

[0017] The beneficial effects of this technical solution are as follows: The method for describing the distribution of dominant areas in tight gas reservoirs containing only intra- and inter-layer water in this invention combines static and dynamic data, using dynamic and static parameters to calculate the abundance of remaining geological reserves, which is realistic and highly accurate. Kriging interpolation is used to obtain water saturation distribution maps and remaining geological reserve abundance distribution maps of blocks, which is convenient and efficient. In this invention, dominant areas are represented by two-dimensional maps, which are visually intuitive. This invention is proposed for tight sandstone gas reservoirs containing only intra- and inter-layer water, without boundary water or bottom water. It can also be applied to conventional gas reservoirs without boundary water or bottom water, making it widely applicable and highly scalable. Using the description method in this invention, a relatively accurate dominant area identification map can be obtained, which has good guiding significance for subsequent new well location deployment and potential tapping of old areas. Attached Figure Description

[0018] Figure 1 This is the technical roadmap for this method.

[0019] Figure 2 This is a graph showing the relationship between fluid mobility efficiency and displacement pressure in three core samples.

[0020] Figure 3 This is the gas-water phase permeability curve of core 7-86.

[0021] Figure 4 This is the gas-water phase permeability curve of core 6-71.

[0022] Figure 5 This is the gas-water phase permeability curve of core 7-30.

[0023] Figure 6 This is a well location distribution map of the SX block.

[0024] Figure 7 This is a map showing the distribution of remaining geological reserves in the SX block.

[0025] Figure 8 This is a map showing the water saturation distribution of the SX block.

[0026] Figure 9 This is the movable water zone map of the SX block.

[0027] Figure 10 This is the advantageous region identification map of the SX block.

[0028] Figure 11 This is a verification image of the superior region identification results of the SX block.

[0029] In the diagram: K rw K represents the relative permeability of the aqueous phase, a dimensionless quantity. rg denoted as gas phase relative permeability, a dimensionless quantity; a represents the well location coordinates; b represents the boundary curve. Detailed Implementation

[0030] The specific embodiments described above further illustrate the purpose, technical solution, and beneficial effects of the present invention. It should be understood that the above descriptions are merely specific embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

[0031] Example 1 This embodiment is the most basic implementation method, a method for describing the distribution of advantageous areas in tight gas reservoirs containing only intra-layer water and inter-layer water, belonging to the technical field of tapping the potential of old oil and gas field development areas. (Reference) Figure 1 This includes the following steps: S1. Collect and organize the dynamic and static parameters of the tight gas reservoir in the target block; S2. Based on the data collected in step S1, select one core sample each from the high-permeability, medium-permeability, and low-permeability tight sandstone reservoirs of a single well, and obtain the saturation of the movable water zones of the three tight sandstone reservoir core samples. S3. Calculate the abundance of remaining geological reserves in a single well; S4. Draw a well location distribution map of the block using the carry coordinates and block boundary coordinates, and interpolate the remaining geological reserves abundance and water saturation of a single well using the well location distribution map. S5. Compare the saturation value of the movable water zone obtained in step S2 with the water saturation value obtained in step S4: When the water saturation value is lower than the saturation of the movable water zone, the block is a low movable water zone; When the water saturation value is equal to or higher than the saturation value of the movable water zone, the area is a high movable water zone. The water saturation distribution map of the block is divided into zones to obtain a movable water zone map; S6. Overlay the remaining geological reserve abundance distribution map of the block with the movable water zone map in step S5 to obtain a dominant area identification map, and determine the intersection of the low movable water zone and the area where the remaining geological reserve abundance is greater than the preset value as the dominant area of the tight gas reservoir.

[0032] With this solution, by combining static data and dynamic data, and calculating the remaining geological reserve abundance using dynamic parameters and static parameters, it conforms to the actual situation and has a high accuracy rate. Obtaining the water saturation distribution map of the block and the remaining geological reserve abundance distribution map of the block by Kriging interpolation method is convenient and efficient; showing the dominant area through two-dimensional maps is vivid and intuitive. It is proposed for tight sandstone gas reservoirs that only contain intra-layer water and inter-layer water, without edge water and bottom water, and can also be applied to conventional gas reservoirs without edge water and bottom water. It has a wide range of applications and strong generalizability. In addition, by using the description method of this solution, a more accurate dominant area identification map can be obtained, which has good guiding significance for the subsequent deployment of new well positions and the potential tapping of old areas.

[0033] Example 2 In this example, taking the SX block of the Sulige Gas Field without edge water and bottom water and only containing intra-layer water and inter-layer water as an example, a more specific description method of the dominant area distribution of the tight gas reservoir is used to further illustrate this technical solution.

[0034] A description method for the distribution of the dominant area of a tight gas reservoir that only contains intra-layer water and inter-layer water, the method includes the following steps: Step 1. Collect the dynamic parameters and static parameters of the tight gas reservoir in the target block; S101. The dynamic parameters include the cumulative production Q of a single well, that is, the cumulative production from the initial production period to the current; S102. Obtain the static parameters including reservoir thickness h, single-well permeability K, single-well porosity Φ, single-well water saturation S w , well location coordinates, and block boundary coordinates through well logging interpretation methods; Step 2. Select 1 core each of high-permeability, medium-permeability, and low-permeability tight sandstone reservoirs in the target block, and conduct centrifugal nuclear magnetic experiments and gas-water relative permeability experiments respectively to obtain the movable water zone saturation; S201. Select cores according to the standard: the high-permeability range is K > 1 mD, the medium-permeability range is 0.3 mD < K < 1 mD, and the low-permeability range is 0.01 mD < K < 0.3 mD; S202. Saturate the 3 cores with water and measure the nuclear magnetic T2 values of the 3 cores under the condition of saturated water. Table 1 is the physical property and nuclear magnetic T2 value table of the 3 selected cores under the condition of saturated water.

[0035] Table 1 S203. Then, centrifuge nuclear magnetic resonance experiments were conducted on the three core samples. Using the correspondence between centrifugation speed and displacement pressure, the bound water saturation corresponding to different displacement pressures of the three core samples was obtained, and the relationship curves between the fluid mobility efficiency and displacement pressure of the three core samples were obtained. Specifically, the three core samples were subjected to nitrogen displacement experiments at centrifuge speeds n of 500 r / min, 1000 r / min, 2000 r / min, 5000 r / min, and 5 MPa, respectively. The relationship between centrifuge speed and displacement pressure was analyzed using the formula... P = lρ w Rn 2 п 2 / 900, l This refers to the core length; the standard core length is 2.54 cm. ρ w ρ is the water density; R is the centrifugation radius; n is the centrifugation speed; P is the displacement pressure; π is pi. Table 2 shows the displacement pressure corresponding to different centrifugation speeds. Table 3 shows the bound water saturation corresponding to different displacement pressures in the three core samples.

[0036] Table 2 Table 3 S204. The optimal displacement pressure is determined by the relationship curve between the fluid mobility efficiency and displacement pressure of the three core samples. The average value of the bound water saturation corresponding to the optimal displacement pressure of the three core samples is taken to obtain the average bound water saturation of the reservoir.

[0037] Specifically, the relationship curves between fluid mobility efficiency and displacement pressure of the aforementioned three core samples were obtained, with reference to... Figure 2 Based on the relationship curve, the optimal displacement pressure can be determined to be 0.51 MPa. The average value of the bound water saturation corresponding to the optimal displacement pressure of the three core samples is taken, and the average bound water saturation of the reservoir is 0.68.

[0038] S205. Gas-water phase permeation experiments were conducted on three core samples to obtain gas-water phase permeation curves. The bound water saturation of the three core samples was obtained through the gas-water phase permeation curves. The average bound water saturation of the three core samples was taken to obtain the average bound water saturation of the reservoir.

[0039] Specifically, the gas-water permeability curves of the aforementioned three core samples were obtained through gas-water permeability experiments, such as... Figure 3-5 As shown, detailed data can be found in Table 4.

[0040] Table 4: Core bound water saturation obtained from air-water phase permeation experiments According to Table 4, the average bound water saturation of the reservoir in the three core samples obtained by the gas-water phase permeation experiment was 0.68.

[0041] S206. The average bound water saturation of the reservoir obtained from centrifugal nuclear magnetic resonance experiments and gas-water phase permeation experiments is averaged to obtain the saturation of the movable water zone.

[0042] Step 3: Calculate the controlled area A of a single well using the area trade-off method, calculate the geological reserves G of a single well using the volumetric method, and calculate the remaining geological reserves abundance of a single well using the formula... Calculate the remaining geological reserve abundance of each individual well, where Ω is the remaining geological reserve abundance of the individual well, in 100 million cubic meters per day; G is the geological reserve of the individual well, in 100 million cubic meters; Q is the cumulative production of the individual well, in 100 million cubic meters; and A is the controlled area of ​​the individual well, in km². 2 ; Among them, the geological reserves of a single well, G, are calculated using the volumetric method formula. The calculation yields the following formula: G represents the geological reserves of a single well; A represents the controlled area of ​​a single well; h represents the reservoir thickness; Φ represents the porosity of a single well; and S represents the reservoir area. w B represents the water saturation of a single well. gi This is the volume factor corresponding to the original formation pressure.

[0043] Step 4: Draw a well location distribution map of the block using the carry coordinates and block boundary coordinates, and interpolate the remaining geological reserves abundance and water saturation of a single well using the well location distribution map. Specifically, a well location distribution map of the block is drawn using carry coordinates and block boundary coordinates, such as... Figure 6 As shown, the remaining geological reserves abundance and water saturation of a single well are interpolated using the block well location distribution map.

[0044] S401. By interpolating the abundance of remaining geological reserves in a single well using Gaussian simulation in the Kriging interpolation method, a distribution map of the abundance of remaining geological reserves in the block is obtained, as follows: Figure 7 As shown.

[0045] S402. By interpolating the water saturation of a single well using Gaussian simulation in the Kriging interpolation method, a water saturation distribution map of the block is obtained, as shown below. Figure 8 As shown.

[0046] Step 5: The movable water saturation values ​​obtained in step S206 are used to determine the movable water saturation zones. Zones with water saturation values ​​lower than the movable water saturation values ​​are classified as low movable water zones, while zones with water saturation values ​​higher than the movable water saturation values ​​are classified as high movable water zones. The block water saturation distribution map is then divided into zones to obtain a movable water saturation map. Specifically, based on the movable water saturation of 0.68 obtained in step two above, the block's water saturation distribution map is divided into high movable water areas and low movable water areas to obtain a movable water zoning map, as shown below. Figure 9 As shown.

[0047] Step Six: Overlay the remaining geological reserve abundance distribution map of the block with the movable water zoning map to obtain the dominant area identification map. The dominant areas of tight gas reservoirs are low movable water areas and areas with remaining geological reserve abundance greater than 0.2Ω. max The intersection of regions, Ω max This represents the maximum remaining geological reserves abundance of a single well, in units of 10. 8 m 3 / km 2 .

[0048] Specifically, by overlaying the remaining geological reserve abundance distribution map of the block with the movable water zoning map, a dominant area identification map is obtained, such as... Figure 10 As shown, this is a map identifying the dominant regions of the SX block.

[0049] Finally, the accuracy was verified by combining data from high-yield wells with unobstructed flow rates exceeding 100,000 cubic meters per day among the new wells of 2020. Figure 11 As shown, a total of 6 new high-yield wells are located in low mobile water zones and have remaining geological reserves greater than 0.2Ω. max The accuracy rate of the data in the intersection of regions is as high as 100%, which shows that it has good guiding significance for the subsequent deployment of new well locations and the tapping of potential in old areas.

Claims

1. A method for describing the distribution of dominant areas in tight gas reservoirs containing only intra-layer and inter-layer water, characterized in that, It includes the following steps: S1. Collect and sort out the dynamic parameters and static parameters of the tight gas reservoir in the target block; S2. Select one core of tight sandstone reservoir with high permeability, medium permeability, and low permeability for each well according to the data collected in step S1, and obtain the movable water zone saturation of the three cores of tight sandstone reservoir; In this step, the movable water zone saturation of the tight sandstone reservoir core is obtained through centrifugal nuclear magnetic experiment and gas-water relative permeability experiment. The method for obtaining the movable water zone saturation includes the following steps: I. Determine the block with a single-well permeability range of K>1 mD as the high-permeability zone, the block with a permeability range of 0.3 mD<K<1 mD as the medium-permeability zone, and the block with a permeability range of 0.01 mD<K<0.3 mD as the low-permeability zone; II. Place the three cores with different permeabilities under saturated water conditions, and measure the nuclear magnetic T2 values of the three cores under saturated water conditions; III. Conduct centrifugal nuclear magnetic experiments on the three cores to obtain the irreducible water saturation corresponding to different displacement pressures of the three cores, and obtain the relationship curve between the fluid mobility efficiency and displacement pressure of the three cores; IV. Determine the optimal displacement pressure through the relationship curve between the fluid mobility efficiency and displacement pressure of the three cores, and take the average value of the irreducible water saturation corresponding to the optimal displacement pressure of the three cores to obtain the reservoir average irreducible water saturation I; V. Conduct gas-water relative permeability experiments on the three cores to obtain gas-water relative permeability curves, obtain the irreducible water saturation of the three cores through the gas-water relative permeability curves, and then take the average value of the irreducible water saturation of the three cores to obtain the reservoir average irreducible water saturation II; VI. Take the average value of the reservoir average irreducible water saturation I obtained in step IV and the reservoir average irreducible water saturation II obtained in step V, and the movable water zone saturation is obtained; S3. Calculate the abundance of remaining geological reserves per well; S4. Draw a well location distribution map of the block using the progressive coordinates and block boundary coordinates, and interpolate the abundance of remaining geological reserves per well and the water saturation per well respectively using the well location distribution map of the block; S5. Compare the movable water zone saturation obtained in step S2 with the water saturation value obtained in step S4: When the water saturation value is lower than the movable water zone saturation, this block is a low movable water zone; When the water saturation value is equal to or higher than the movable water zone saturation, this block is a high movable water zone, Partition the water saturation distribution map of the block to obtain the movable water zone map; S6. Overlay the remaining geological reserve abundance distribution map of the block with the movable water zoning map from step S5 to obtain the dominant area identification map, and classify low movable water areas and areas with remaining geological reserve abundance greater than 0.2Ω. max The intersection of the regions was identified as the dominant area for tight gas reservoirs, where Ω max This represents the maximum abundance of remaining geological reserves in a single well.

2. The method for describing the distribution of dominant areas in tight gas reservoirs containing only intra-layer water and inter-layer water according to claim 1, characterized in that: In step S1, the dynamic parameters include the cumulative production Q per well.

3. The method for describing the distribution of dominant areas in tight gas reservoirs containing only intra-layer water and inter-layer water according to claim 2, characterized in that: In step S1, the static parameters include the reservoir thickness h, the single-well permeability K, the single-well porosity Φ, the single-well water saturation Sw, the well location coordinates, and the block boundary coordinates.

4. The method for describing the distribution of dominant areas in tight gas reservoirs containing only intra-layer water and inter-layer water according to claim 3, characterized in that: In step III, the relationship between centrifugal speed and displacement pressure is as follows: P = lρ w Rn 2 π 2 / 900, l This refers to the core length; the standard core length is 2.54 cm. ρ w For the density of water, R Where is the centrifugal radius, n Centrifugal speed, P To relieve pressure, π Pi is the mathematical constant of a circle.

5. The method for describing the distribution of dominant areas in tight gas reservoirs containing only intra-layer water and inter-layer water according to claim 4, characterized in that, In step S3, the calculation method of the abundance of remaining geological reserves per well is: obtain the single-well controlled area A, obtain the single-well geological reserve G, and calculate the abundance value Ω of the remaining geological reserves per well through the calculation formula of the abundance of remaining geological reserves per well Ω=(G-Q) / A.

6. The method for describing the distribution of dominant areas in tight gas reservoirs containing only intra-layer water and inter-layer water according to claim 5, characterized in that: The single-well controlled area A is calculated by the area weighing method, and the single-well geological reserve G is calculated by the volume method.

7. The method for describing the distribution of dominant areas in tight gas reservoirs containing only intra-layer water and inter-layer water according to claim 1, characterized in that: In step S4, the abundance of remaining geological reserves in a single well is interpolated using Gaussian simulation in the Kriging interpolation method to obtain a distribution map of the abundance of remaining geological reserves in the block; the water saturation of a single well is interpolated using Gaussian simulation in the Kriging interpolation method to obtain a distribution map of the water saturation in the block.

8. The method for describing the distribution of dominant areas in tight gas reservoirs containing only intra-layer water and inter-layer water according to claim 3, characterized in that: In step S1, the static parameters are obtained through well logging interpretation methods.

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