A carbonate gas reservoir gas well production allocation method

Abstract

The application discloses a carbonate rock gas reservoir gas well production allocation method and belongs to the technical field of oil and gas exploitation. AOF ; c, a function relationship between the thickness proportion of different types of reservoirs and the open flow capacity of newly deployed gas wells q' AOF ; d, a single well numerical simulation model is established, a relationship curve between each production allocation proportion and cumulative production is established, a tangent is drawn, and a reasonable production allocation proportion of the gas well is determined; e, the product of the open flow capacity of the newly deployed gas well and the reasonable production allocation proportion of the gas well is the reasonable production of the newly deployed gas well. The application can realize reasonable production allocation of the newly deployed gas well without dynamic data such as testing, oil testing, well testing and production, and can effectively guide deployment of the new well.

Description

Technical Field

[0001] This invention relates to the field of oil and gas extraction technology, and in particular to a method for production allocation in carbonate gas reservoirs. Background Technology

[0002] The rational production allocation method for gas wells mainly targets wells with existing dynamic data, requiring the use of testing, well testing, and production data for allocation. However, for newly deployed gas wells, since testing, well testing, and production data have not yet been collected, no dynamic data can be obtained. Therefore, existing technologies are difficult to apply to the rational production allocation of newly deployed gas wells, making it impossible to determine the appropriate production scale and predict the cumulative gas production. Consequently, it is impossible to provide technical support for determining whether newly deployed gas wells are suitable for implementation.

[0003] Chinese patent document CN113445988A, published on September 28, 2021, discloses a method for evaluating the production capacity of gas wells in low-permeability carbonate gas reservoirs. The method includes the following steps: selecting a low-permeability carbonate gas reservoir well as the target well; dividing the gas field or block containing the target well into flow units based on a flow unit division method, and determining the flow unit containing the target well; dividing the target well into different production stages, including early development, mid-development, and late development; obtaining production test data to evaluate the production capacity of the target well at different production stages; and evaluating the production capacity of the target well at different production stages based on the flow units and the production test data.

[0004] The patent document discloses a method for evaluating the production capacity of gas wells in low-permeability carbonate gas reservoirs. This method eliminates the need for any production capacity testing during the well's production cycle, requiring only conventional production data from on-site testing. It enables continuous, rapid, and accurate evaluation and management of gas well production capacity, providing a basis for well management and adjustment, and for gas field development planning. However, since the evaluation of gas well production capacity can only be conducted using conventional on-site production data after the well has commenced production, it is impossible to rationally allocate production for newly deployed gas wells without dynamic data from testing, well trials, and production. This method cannot effectively guide the deployment of new wells. Summary of the Invention

[0005] In order to overcome the shortcomings of the prior art, the present invention provides a method for allocating production of gas wells in carbonate gas reservoirs. The present invention can achieve reasonable production allocation of newly deployed gas wells without the need for dynamic data such as testing, oil testing, well testing and production, and can effectively guide the deployment of new wells.

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

[0007] A method for production allocation in a carbonate gas reservoir well, characterized by comprising the following steps:

[0008] a. Based on reservoir characteristics, classify reservoirs into several different types of reservoirs and obtain the thickness percentage of different types of reservoirs in existing gas wells.

[0009] b. Based on existing gas well production logging data, obtain the test production, formation pressure, and bottom hole flowing pressure for different types of reservoirs, and calculate the free flow rate q. AOF ;

[0010] c. Establish the thickness ratio of different types of reservoirs and the relationship between the thickness ratio and the newly deployed gas wells q′ AOF The functional relationship of unobstructed flow rate;

[0011] d. Using existing geological and dynamic data of gas wells, establish a single-well numerical simulation model. In the single-well numerical simulation model, set at least four different production ratios and predict the cumulative production of the gas well for at least 20 years under each production ratio condition. Establish the relationship curve between each production ratio and the cumulative production. By plotting the tangent, determine the reasonable production ratio of the gas well.

[0012] e. Import the thickness data of different types of reservoirs of existing gas wells into the 3D geological modeling software to establish 3D models of different types of reservoirs. Import the well trajectory data of newly deployed gas wells into the 3D geological modeling software. In the established 3D models of different types of reservoirs, create profiles of different types of reservoirs passing through the well trajectory of the newly deployed gas wells. Statistically obtain the thickness percentage of different types of reservoirs through which the well trajectory of the newly deployed gas wells passes, and calculate the unobstructed flow rate of the newly deployed gas wells. The product of the unobstructed flow rate of the newly deployed gas wells and the reasonable production ratio of the gas wells is the reasonable production ratio of the newly deployed gas wells.

[0013] In step a, reservoir characteristics include reservoir lithology, fracture and vulnerability development, logging response, porosity, permeability, and reservoir mobility.

[0014] In step b, the unobstructed flow rate q is calculated. AOF Specifically, it refers to calculation using Equation 1;

[0015]

[0016] In the formula, q AOF For unobstructed flow, 10 4 m 3 / d; n is the total number of reservoir types encountered by the gas well, an integer; q AOFi For the unobstructed flow rate of the i-th type of storage, 10 4 m 3 / d;q gi For the test yield of the i-th type of storage group, 10 4 m3 / d;P ri P represents the formation pressure of the i-th type reservoir, in MPa; wfi Let be the bottom-flow pressure of the i-th type of reservoir, in MPa.

[0017] In step c, the thickness ratio of different types of reservoirs and the newly deployed gas well q′ AOF The functional relationship of the unobstructed flow rate specifically refers to Equation 2;

[0018]

[0019] In the formula, q′ AOF For the unobstructed flow rate of the newly deployed gas wells, 10 4 m 3 / d; n is the total number of reservoir types encountered by the gas well, an integer; w i The thickness percentage of the i-th type of reservoir is %.

[0020] In step d, establishing a single-well numerical simulation model specifically refers to using Eclipse numerical simulation software.

[0021] In step d, the production allocation ratio specifically refers to the percentage of unobstructed flow rate. There are six production allocation ratios: 1 / 3, 1 / 4, 1 / 5, 1 / 6, 1 / 7, and 1 / 8.

[0022] In step d, determining the reasonable production ratio of gas wells by tangent plotting specifically means drawing tangents to the two endpoints of the curve relating each production ratio to the cumulative production. The two tangents intersect at point A. The angle bisector of the included angle between the two tangents is drawn through point A and intersects the curve at point B. The x-coordinate of point B is the reasonable production ratio of the gas well.

[0023] In step e, the three-dimensional geological modeling software is Petrel.

[0024] In step e, determining the unobstructed flow rate of the newly deployed gas well specifically refers to calculating the thickness ratio of different types of reservoirs and the unobstructed flow rate q. AOF The functional relationship is obtained.

[0025] In step a, classifying reservoirs specifically refers to dividing the reservoirs of existing gas wells into Class I, Class II, and Class III reservoirs according to the reservoir classification standards.

[0026] The Eclipse mentioned in this invention refers to a cross-platform open-source integrated development environment.

[0027] The Petrel mentioned in this invention refers to a 3D visualization modeling software.

[0028] The beneficial effects of this invention are mainly reflected in the following aspects:

[0029] 1. This invention, a) classifies reservoirs according to reservoir characteristics, dividing existing gas well reservoirs into several different types of reservoirs and obtaining the thickness percentage of different types of reservoirs in existing gas wells; b) based on the production logging data of existing gas wells, obtains the test production, formation pressure, and bottom hole flowing pressure of different types of reservoirs, and calculates the free flow rate q. AOF c. Establish the thickness ratio and unobstructed flow rate q for different types of reservoirs. AOF The functional relationship; d. Based on the geological and dynamic data of existing gas wells, establish a single-well numerical simulation model. In the single-well numerical simulation model, set at least four different production ratios and predict the cumulative production corresponding to the gas well's continuous production for at least 20 years under each production ratio condition. Establish the relationship curve between each production ratio and the cumulative production. Determine the reasonable production ratio of the gas well by plotting the tangent; e. Import the thickness data of different types of reservoirs of existing gas wells into the three-dimensional geological modeling software to establish three-dimensional models of different types of gas reservoirs. Import the well trajectory data of newly deployed gas wells into the three-dimensional geological modeling software. In the established three-dimensional models of different types of gas reservoirs, create profiles of different types of reservoirs passing through the well trajectory of the newly deployed gas wells. Statistically obtain the thickness percentage of different types of reservoirs through which the well trajectory of the newly deployed gas wells passes based on the profiles of different types of reservoirs. Calculate the unobstructed flow rate of the newly deployed gas wells. The product of the unobstructed flow rate of the newly deployed gas wells and the reasonable production ratio of the gas wells is the reasonable production ratio of the newly deployed gas wells. Compared to existing technologies, this technology enables the rational allocation of production for newly deployed gas wells without the need for dynamic data such as testing, oil testing, well testing, and production data, and can effectively guide the deployment of new wells.

[0030] 2. This invention addresses the characteristic of carbonate gas reservoirs having multiple reservoir types. Based on the geological and dynamic data of a limited number of existing gas wells, and in the absence of any dynamic data on newly deployed wells, it provides technical support for determining whether newly deployed gas wells are feasible for implementation by determining the reasonable production scale of the newly deployed gas wells and predicting the cumulative gas production of the gas wells.

[0031] 3. This invention establishes a method for calculating the unobstructed flow rate of gas wells when different types of reservoirs are superimposed. This method is more precise than the traditional "one-point method" and the calculation results are more reliable.

[0032] 4. This invention establishes a functional relationship between the thickness ratio of different types of reservoirs and the unobstructed flow rate of newly deployed gas wells. Using this functional relationship, the unobstructed flow rate of newly deployed wells can be predicted even when no dynamic data of the newly deployed wells can be obtained.

[0033] 5. This invention uses tangent plotting to quickly calculate the reasonable production ratio of gas wells, which is not only simple to operate, but also fast and effective. Attached Figure Description

[0034] The present invention will now be further described in detail with reference to the accompanying drawings and specific embodiments:

[0035] Figure 1 This is a schematic diagram showing the relationship between the production ratio and cumulative output of the present invention. Detailed Implementation

[0036] Example 1

[0037] See Figure 1 A method for production allocation in a carbonate gas reservoir well includes the following steps:

[0038] a. Based on reservoir characteristics, classify reservoirs into several different types of reservoirs and obtain the thickness percentage of different types of reservoirs in existing gas wells.

[0039] b. Based on existing gas well production logging data, obtain the test production, formation pressure, and bottom hole flowing pressure for different types of reservoirs, and calculate the free flow rate q. AOF ;

[0040] c. Establish the thickness ratio of different types of reservoirs and the relationship between the thickness ratio and the newly deployed gas wells q′ AOF The functional relationship of unobstructed flow rate;

[0041] d. Using existing geological and dynamic data of gas wells, establish a single-well numerical simulation model. In the single-well numerical simulation model, set at least four different production ratios and predict the cumulative production of the gas well for at least 20 years under each production ratio condition. Establish the relationship curve between each production ratio and the cumulative production. By plotting the tangent, determine the reasonable production ratio of the gas well.

[0042] e. Import the thickness data of different types of reservoirs of existing gas wells into the 3D geological modeling software to establish 3D models of different types of reservoirs. Import the well trajectory data of newly deployed gas wells into the 3D geological modeling software. In the established 3D models of different types of reservoirs, create profiles of different types of reservoirs passing through the well trajectory of the newly deployed gas wells. Statistically obtain the thickness percentage of different types of reservoirs through which the well trajectory of the newly deployed gas wells passes, and calculate the unobstructed flow rate of the newly deployed gas wells. The product of the unobstructed flow rate of the newly deployed gas wells and the reasonable production ratio of the gas wells is the reasonable production ratio of the newly deployed gas wells.

[0043] This embodiment is the most basic implementation method. Even without dynamic data such as testing, oil testing, well testing, and production, it can achieve reasonable production allocation for newly deployed gas wells and effectively guide the deployment of new wells.

[0044] Example 2

[0045] See Figure 1A method for production allocation in a carbonate gas reservoir well includes the following steps:

[0046] a. Based on reservoir characteristics, classify reservoirs into several different types of reservoirs and obtain the thickness percentage of different types of reservoirs in existing gas wells.

[0047] b. Based on existing gas well production logging data, obtain the test production, formation pressure, and bottom hole flowing pressure for different types of reservoirs, and calculate the free flow rate q. AOF ;

[0048] c. Establish the thickness ratio of different types of reservoirs and the relationship between the thickness ratio and the newly deployed gas wells q′ AOF The functional relationship of unobstructed flow rate;

[0049] d. Using existing geological and dynamic data of gas wells, establish a single-well numerical simulation model. In the single-well numerical simulation model, set at least four different production ratios and predict the cumulative production of the gas well for at least 20 years under each production ratio condition. Establish the relationship curve between each production ratio and the cumulative production. By plotting the tangent, determine the reasonable production ratio of the gas well.

[0050] e. Import the thickness data of different types of reservoirs of existing gas wells into the 3D geological modeling software to establish 3D models of different types of reservoirs. Import the well trajectory data of newly deployed gas wells into the 3D geological modeling software. In the established 3D models of different types of reservoirs, create profiles of different types of reservoirs passing through the well trajectory of the newly deployed gas wells. Statistically obtain the thickness percentage of different types of reservoirs through which the well trajectory of the newly deployed gas wells passes, and calculate the unobstructed flow rate of the newly deployed gas wells. The product of the unobstructed flow rate of the newly deployed gas wells and the reasonable production ratio of the gas wells is the reasonable production ratio of the newly deployed gas wells.

[0051] In step a, reservoir characteristics include reservoir lithology, fracture and vulnerability development, logging response, porosity, permeability, and reservoir mobility.

[0052] This embodiment is a preferred implementation method. Considering that carbonate gas reservoirs have multiple reservoir types, based on the geological and dynamic data of a few existing gas wells, and in the absence of any dynamic data on newly deployed wells, it can provide technical support for determining whether newly deployed gas wells are feasible by determining the reasonable production scale of the newly deployed gas wells and predicting the cumulative gas production of the gas wells.

[0053] Example 3

[0054] See Figure 1 A method for production allocation in a carbonate gas reservoir well includes the following steps:

[0055] a. Based on reservoir characteristics, classify reservoirs into several different types of reservoirs and obtain the thickness percentage of different types of reservoirs in existing gas wells.

[0056] b. Based on existing gas well production logging data, obtain the test production, formation pressure, and bottom hole flowing pressure for different types of reservoirs, and calculate the free flow rate q. AOF ;

[0057] c. Establish the thickness ratio of different types of reservoirs and the relationship between the thickness ratio and the newly deployed gas wells q′ AOF The functional relationship of unobstructed flow rate;

[0058] d. Using existing geological and dynamic data of gas wells, establish a single-well numerical simulation model. In the single-well numerical simulation model, set at least four different production ratios and predict the cumulative production of the gas well for at least 20 years under each production ratio condition. Establish the relationship curve between each production ratio and the cumulative production. By plotting the tangent, determine the reasonable production ratio of the gas well.

[0059] e. Import the thickness data of different types of reservoirs of existing gas wells into the 3D geological modeling software to establish 3D models of different types of reservoirs. Import the well trajectory data of newly deployed gas wells into the 3D geological modeling software. In the established 3D models of different types of reservoirs, create profiles of different types of reservoirs passing through the well trajectory of the newly deployed gas wells. Statistically obtain the thickness percentage of different types of reservoirs through which the well trajectory of the newly deployed gas wells passes, and calculate the unobstructed flow rate of the newly deployed gas wells. The product of the unobstructed flow rate of the newly deployed gas wells and the reasonable production ratio of the gas wells is the reasonable production ratio of the newly deployed gas wells.

[0060] In step a, reservoir characteristics include reservoir lithology, fracture and vulnerability development, logging response, porosity, permeability, and reservoir mobility.

[0061] In step b, the unobstructed flow rate q is calculated. AOF Specifically, it refers to calculation using Equation 1;

[0062]

[0063] In the formula, q AOF For unobstructed flow, 10 4 m 3 / d; n is the total number of reservoir types encountered by the gas well, an integer; q AOFi For the unobstructed flow rate of the i-th type of storage, 10 4 m 3 / d;q gi For the test yield of the i-th type of storage group, 10 4 m 3 / d;P riP represents the formation pressure of the i-th type reservoir, in MPa; wfi Let be the bottom-flow pressure of the i-th type of reservoir, in MPa.

[0064] This embodiment is another preferred implementation method, which establishes a method for calculating the unobstructed flow rate of gas wells when different types of reservoirs are superimposed. It is more precise than the traditional "one-point method" and the calculation results are more reliable.

[0065] Example 4

[0066] See Figure 1 A method for production allocation in a carbonate gas reservoir well includes the following steps:

[0067] a. Based on reservoir characteristics, classify reservoirs into several different types of reservoirs and obtain the thickness percentage of different types of reservoirs in existing gas wells.

[0068] b. Based on existing gas well production logging data, obtain the test production, formation pressure, and bottom hole flowing pressure for different types of reservoirs, and calculate the free flow rate q. AOF ;

[0069] c. Establish the thickness ratio of different types of reservoirs and the relationship between the thickness ratio and the newly deployed gas wells q′ AOF The functional relationship of unobstructed flow rate;

[0070] d. Using existing geological and dynamic data of gas wells, establish a single-well numerical simulation model. In the single-well numerical simulation model, set at least four different production ratios and predict the cumulative production of the gas well for at least 20 years under each production ratio condition. Establish the relationship curve between each production ratio and the cumulative production. By plotting the tangent, determine the reasonable production ratio of the gas well.

[0071] e. Import the thickness data of different types of reservoirs of existing gas wells into the 3D geological modeling software to establish 3D models of different types of reservoirs. Import the well trajectory data of newly deployed gas wells into the 3D geological modeling software. In the established 3D models of different types of reservoirs, create profiles of different types of reservoirs passing through the well trajectory of the newly deployed gas wells. Statistically obtain the thickness percentage of different types of reservoirs through which the well trajectory of the newly deployed gas wells passes, and calculate the unobstructed flow rate of the newly deployed gas wells. The product of the unobstructed flow rate of the newly deployed gas wells and the reasonable production ratio of the gas wells is the reasonable production ratio of the newly deployed gas wells.

[0072] In step a, reservoir characteristics include reservoir lithology, fracture and vulnerability development, logging response, porosity, permeability, and reservoir mobility.

[0073] In step b, the unobstructed flow rate q is calculated. AOF Specifically, it refers to calculation using Equation 1;

[0074]

[0075] In the formula, q AOF For unobstructed flow, 10 4 m 3 / d; n is the total number of reservoir types encountered by the gas well, an integer; q AOFi For the unobstructed flow rate of the i-th type of storage, 10 4 m 3 / d;q gi For the test yield of the i-th type of storage group, 10 4 m 3 / d;P ri P represents the formation pressure of the i-th type reservoir, in MPa; wfi Let be the bottom-flow pressure of the i-th type of reservoir, in MPa.

[0076] In step c, the thickness ratio of different types of reservoirs and the newly deployed gas well q′ AOF The functional relationship of the unobstructed flow rate specifically refers to Equation 2;

[0077]

[0078] In the formula, q′ AOF For the unobstructed flow rate of the newly deployed gas wells, 10 4 m 3 / d; n is the total number of reservoir types encountered by the gas well, an integer; w i The thickness percentage of the i-th type of reservoir is %.

[0079] In step d, establishing a single-well numerical simulation model specifically refers to using Eclipse numerical simulation software.

[0080] In step d, the production allocation ratio specifically refers to the percentage of unobstructed flow rate. There are six production allocation ratios: 1 / 3, 1 / 4, 1 / 5, 1 / 6, 1 / 7, and 1 / 8.

[0081] This embodiment is another preferred implementation method. It establishes a functional relationship between the thickness ratio of different types of reservoirs and the unobstructed flow rate of newly deployed gas wells. Using this functional relationship, the unobstructed flow rate of newly deployed wells can be predicted even when no dynamic data of the newly deployed wells can be obtained.

[0082] Example 5

[0083] See Figure 1 A method for production allocation in a carbonate gas reservoir well includes the following steps:

[0084] a. Based on reservoir characteristics, classify reservoirs into several different types of reservoirs and obtain the thickness percentage of different types of reservoirs in existing gas wells.

[0085] b. Based on existing gas well production logging data, obtain the test production, formation pressure, and bottom hole flowing pressure for different types of reservoirs, and calculate the free flow rate q. AOF ;

[0086] c. Establish the thickness ratio of different types of reservoirs and the relationship between the thickness ratio and the newly deployed gas wells q′ AOF The functional relationship of unobstructed flow rate;

[0087] d. Using existing geological and dynamic data of gas wells, establish a single-well numerical simulation model. In the single-well numerical simulation model, set at least four different production ratios and predict the cumulative production of the gas well for at least 20 years under each production ratio condition. Establish the relationship curve between each production ratio and the cumulative production. By plotting the tangent, determine the reasonable production ratio of the gas well.

[0088] e. Import the thickness data of different types of reservoirs of existing gas wells into the 3D geological modeling software to establish 3D models of different types of reservoirs. Import the well trajectory data of newly deployed gas wells into the 3D geological modeling software. In the established 3D models of different types of reservoirs, create profiles of different types of reservoirs passing through the well trajectory of the newly deployed gas wells. Statistically obtain the thickness percentage of different types of reservoirs through which the well trajectory of the newly deployed gas wells passes, and calculate the unobstructed flow rate of the newly deployed gas wells. The product of the unobstructed flow rate of the newly deployed gas wells and the reasonable production ratio of the gas wells is the reasonable production ratio of the newly deployed gas wells.

[0089] In step a, reservoir characteristics include reservoir lithology, fracture and vulnerability development, logging response, porosity, permeability, and reservoir mobility.

[0090] In step b, the unobstructed flow rate q is calculated. AOF Specifically, it refers to calculation using Equation 1;

[0091]

[0092] In the formula, q AOF For unobstructed flow, 10 4 m 3 / d; n is the total number of reservoir types encountered by the gas well, an integer; q AOFi For the unobstructed flow rate of the i-th type of storage, 10 4 m 3 / d;q gi For the test yield of the i-th type of storage group, 10 4 m 3 / d;P riP represents the formation pressure of the i-th type reservoir, in MPa; wfi Let be the bottom-flow pressure of the i-th type of reservoir, in MPa.

[0093] In step c, the thickness ratio of different types of reservoirs and the newly deployed gas well q′ AOF The functional relationship of the unobstructed flow rate specifically refers to Equation 2;

[0094]

[0095] In the formula, q′ AOF For the unobstructed flow rate of the newly deployed gas wells, 10 4 m 3 / d; n is the total number of reservoir types encountered by the gas well, an integer; w i The thickness percentage of the i-th type of reservoir is %.

[0096] In step d, establishing a single-well numerical simulation model specifically refers to using Eclipse numerical simulation software.

[0097] In step d, the production allocation ratio specifically refers to the percentage of unobstructed flow rate. There are six production allocation ratios: 1 / 3, 1 / 4, 1 / 5, 1 / 6, 1 / 7, and 1 / 8.

[0098] In step d, determining the reasonable production ratio of gas wells by tangent plotting specifically means drawing tangents to the two endpoints of the curve relating each production ratio to the cumulative production. The two tangents intersect at point A. The angle bisector of the included angle between the two tangents is drawn through point A and intersects the curve at point B. The x-coordinate of point B is the reasonable production ratio of the gas well.

[0099] In step e, the three-dimensional geological modeling software is Petrel.

[0100] In step e, determining the unobstructed flow rate of the newly deployed gas well specifically refers to calculating the thickness ratio of different types of reservoirs and the flow rate of the newly deployed gas well q′. AOF The functional relationship of the unobstructed flow rate is obtained.

[0101] Furthermore, in step a, classifying the reservoir specifically refers to dividing the existing gas well reservoirs into Class I, Class II, and Class III reservoirs according to the reservoir classification standard.

[0102] This embodiment is the best implementation method. It uses tangent plotting to quickly calculate the reasonable production ratio of gas wells. It is not only easy to operate, but also fast and effective.

[0103] The invention will be described in detail below using a specific example of newly deployed gas wells in carbonate gas reservoirs:

[0104] 1. Based on the reservoir lithology, fracture and vulnerability development, logging response, porosity, permeability and reservoir mobility characteristics of carbonate gas reservoirs, a reservoir classification standard is established. See Table 1. Existing gas well reservoirs are divided into three types of reservoirs: Class I, Class II and Class III, thereby obtaining the thickness and proportion of the three types of reservoirs in existing gas wells.

[0105] Table 1

[0106]

[0107] 2. By conducting production logging of existing gas wells, the test production, formation pressure, and bottom hole flowing pressure of various reservoirs are obtained. These values ​​are then substituted into Equation 1 to obtain the unobstructed flow rate q. AOF ;

[0108]

[0109] In the formula: q AOF1 For a type of storage system with unobstructed flow, 10 4 m 3 / d;q AOF2 For Class II storage, the unobstructed flow rate is 10. 4 m 3 / d;q AOF3 For Class III storage, the unobstructed flow rate is 10. 4 m 3 / d;q g1 For the test production of a type of storage group, 10 4 m 3 / d;q g2 For the test production of Class II storage, 10 4 m 3 / d;q g3 For the test production of the three types of storage, 10 4 m 3 / d;P r1 For a type of reservoir, the formation pressure is MPa; P r2 The formation pressure of the Class II reservoir is MPa; P r3 Formation pressure for Class III reservoirs, MPa; P wf1 The bottom-hole flowing pressure of a Class I reservoir is measured in MPa; P wf2 The bottom-hole flowing pressure of a Class II reservoir is MPa; P wf3 The bottom-hole flowing pressure of the Class III reservoir is MPa;

[0110] 3. Based on the reservoir thickness ratio of existing wells and their corresponding unobstructed flow rates, establish the relationship between the thickness ratio of different types of reservoirs and the newly deployed gas well q′. AOF The unobstructed flow rate is given by equation 2. Based on equation 2, the unobstructed flow rate of newly deployed gas wells can be predicted.

[0111]

[0112] In the formula, q′ AOF For the unobstructed flow rate of the newly deployed gas wells, 10 4 m 3 / d; w1 is the thickness percentage of Class I reservoirs, %; w2 is the thickness percentage of Class II reservoirs, %; w3 is the thickness percentage of Class III reservoirs, %;

[0113] 4. Using existing geological and dynamic data of gas wells, establish a single-well numerical simulation model using Eclipse numerical simulation software;

[0114] The production allocation of gas wells is generally set as a percentage of the gas well's unobstructed flow rate. The percentage is the production allocation ratio of the gas well. In the single-well numerical simulation model, there are 6 production allocation ratios: 1 / 3, 1 / 4, 1 / 5, 1 / 6, 1 / 7, and 1 / 8.

[0115] Using the established single-well numerical simulation model, the cumulative production of a gas well after 25 years of continuous production is predicted under each production ratio, thereby establishing the relationship curve between each production ratio and the cumulative production.

[0116] Draw tangents to the two endpoints of the relationship curve. The two tangents intersect at point A. Draw the bisector of the angle between the two tangents through point A and intersect the curve at point B. The x-coordinate of point B, 18%, is the reasonable production ratio of the gas well.

[0117] 5. Import the thickness data of various reservoirs of existing gas wells into the 3D geological modeling software, and use the facies modeling method to establish a 3D model of the gas reservoir containing different types of reservoirs.

[0118] Import the well trajectory data of the newly deployed gas wells into the 3D geological modeling software. In the 3D models of different types of gas reservoirs that have been established, create profiles of different types of reservoirs through the well trajectory of the newly deployed gas wells. Statistical analysis shows that the thickness of the newly deployed gas well trajectory passing through the first type of reservoir is 74%, the thickness passing through the second type of reservoir is 21%, and the thickness passing through the third type of reservoir is 5%.

[0119] Using the thickness proportions of Class I, Class II, and Class III reservoirs, the unobstructed flow rate of the newly deployed gas well is obtained as 208.4 × 10⁻⁶ using Equation 2. 4 m 3 / d, then via Figure 1 The reasonable production allocation ratio for 18% of gas wells, obtained from the relationship curve between production allocation ratio and cumulative production, can be used to determine the reasonable production allocation for newly deployed gas wells as 37.5 × 10⁻⁶. 4 m 3Based on a 330-day year, the predicted reasonable annual production scale for newly deployed gas wells is 1.24 × 10⁶ days per day. 8 m 3 See Table 2.

[0120] Table 2

[0121] parameter unit numerical values The proportion of Class I reservoir thickness ％ 74 The proportion of Class II reservoir thickness ％ 21 Thickness of the three types of reservoirs ％ 5 Unobstructed flow <![CDATA[10 4 m 3 / d]]> 208.4 Reasonable production ratio ％ 18 Reasonable production allocation <![CDATA[10 4 m 3 / d]]> 37.5

[0122] In summary, the gas well production allocation method of this invention can achieve reasonable production allocation for newly deployed gas wells even without dynamic data such as testing, oil testing, well testing, and production, and can effectively guide the deployment of new wells.

Claims

1. A method for production allocation in a carbonate gas reservoir well, characterized in that, Includes the following steps: a. Based on reservoir characteristics, classify reservoirs into several different types of reservoirs and obtain the thickness percentage of different types of reservoirs in existing gas wells. b. Based on existing gas well production logging data, obtain the test production, formation pressure, and bottom hole flowing pressure for different types of reservoirs, and calculate the free flow rate q. AOF ; c. Establish the thickness ratio of different types of reservoirs and the relationship between the thickness of newly deployed gas wells and q′. AOF The functional relationship of unobstructed flow rate; d. Using existing geological and dynamic data of gas wells, establish a single-well numerical simulation model. In the single-well numerical simulation model, set at least four different production ratios and predict the cumulative production of the gas well for at least 20 years under each production ratio condition. Establish the relationship curve between each production ratio and the cumulative production. By plotting the tangent, determine the reasonable production ratio of the gas well. e. Import the thickness data of different types of reservoirs of existing gas wells into the 3D geological modeling software to establish 3D models of different types of reservoirs. Import the well trajectory data of newly deployed gas wells into the 3D geological modeling software. In the established 3D models of different types of reservoirs, create profiles of different types of reservoirs passing through the well trajectory of the newly deployed gas wells. Statistically obtain the thickness percentage of different types of reservoirs through which the well trajectory of the newly deployed gas wells passes, and calculate the unobstructed flow rate of the newly deployed gas wells. The product of the unobstructed flow rate of the newly deployed gas wells and the reasonable production ratio of the gas wells is the reasonable production ratio of the newly deployed gas wells.

2. The method for production allocation of gas wells in a carbonate gas reservoir according to claim 1, characterized in that: In step a, reservoir characteristics include reservoir lithology, fracture and vulnerability development, logging response, porosity, permeability, and reservoir mobility.

3. The method for production allocation of gas wells in carbonate gas reservoirs according to claim 1, characterized in that: In step b, the unobstructed flow rate q is calculated. AOF Specifically, it refers to calculation using Equation 1; In the formula, q AOF For unobstructed flow, 10 4 m 3 / d; n is the total number of reservoir types encountered by the gas well, an integer; q AOFi For the unobstructed flow rate of the i-th type of storage, 10 4 m 3 / d;q gi For the test yield of the i-th type of storage group, 10 4 m 3 / d;P ri P represents the formation pressure of the i-th type reservoir, in MPa; wfi Let be the bottom-flow pressure of the i-th type of reservoir, in MPa.

4. The method for production allocation of gas wells in carbonate gas reservoirs according to claim 1, characterized in that: In step c, the thickness ratio of different types of reservoirs and the newly deployed gas well q′ AOF The functional relationship of the unobstructed flow rate specifically refers to Equation 2; In the formula, q′ AOF For the unobstructed flow rate of the newly deployed gas wells, 10 4 m 3 / d; n is the total number of reservoir types encountered by the gas well, an integer; w i The thickness percentage of the i-th type of reservoir is %.

5. The method for production allocation of gas wells in carbonate gas reservoirs according to claim 1, characterized in that: In step d, establishing a single-well numerical simulation model specifically refers to using Eclipse numerical simulation software.

6. The method for production allocation of gas wells in a carbonate gas reservoir according to claim 1, characterized in that: In step d, the production allocation ratio specifically refers to the percentage of unobstructed flow rate. There are six production allocation ratios: 1 / 3, 1 / 4, 1 / 5, 1 / 6, 1 / 7, and 1 / 8.

7. The method for production allocation of gas wells in carbonate gas reservoirs according to claim 1, characterized in that: In step d, determining the reasonable production ratio of gas wells by tangent plotting specifically means drawing tangents to the two endpoints of the curve relating each production ratio to the cumulative production. The two tangents intersect at point A. The angle bisector of the included angle between the two tangents is drawn through point A and intersects the curve at point B. The x-coordinate of point B is the reasonable production ratio of the gas well.

8. The method for production allocation of gas wells in a carbonate gas reservoir according to claim 1, characterized in that: In step e, the three-dimensional geological modeling software is Petrel.

9. The method for production allocation of gas wells in a carbonate gas reservoir according to claim 1, characterized in that: In step e, determining the unobstructed flow rate of the newly deployed gas well specifically refers to calculating the thickness ratio of different types of reservoirs and the flow rate of the newly deployed gas well q′. AOF The functional relationship of the unobstructed flow rate is obtained.

10. A method for production allocation in a carbonate gas reservoir according to claim 1, characterized in that: In step a, classifying reservoirs specifically refers to dividing the reservoirs of existing gas wells into Class I, Class II, and Class III reservoirs according to the reservoir classification standards.

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