Multi-layer tight sandstone gas reservoir investment cost splitting method

Abstract

The invention discloses a multi-layer tight sandstone gas reservoir investment cost splitting method, which comprises the following steps: collecting data of a block to be evaluated, establishing a relationship between gas test data and an energy storage coefficient, correcting the energy storage coefficient, calculating a gas production contribution rate of each layer based on the corrected energy storage coefficient, and splitting the investment cost of the multi-layer tight sandstone gas reservoir on the basis of the gas production contribution rate. And splitting the investment cost of the multi-layer shared facility. The method solves the problems that the existing method is not economical for single-layer evaluation, reserves are lost, and when investment cost splitting is carried out according to gas production profile data, calculation cannot be carried out due to data shortage.

Description

Technical Field

[0001] The invention belongs to the technical field of oil exploration and development cost splitting methods, and in particular relates to a multi-layer tight sandstone gas reservoir investment cost splitting method. Background Art

[0002] The development of tight sandstone gas reservoirs, especially the development of gas reservoirs with multiple gas-bearing strata, is often carried out by multi-layer commingled production. However, when submitting reserves, they are basically submitted as single layers. Such multi-layer superimposed development gas reservoirs are usually developed by multi-layer shared facilities (drilling and surface facilities). Therefore, when evaluating single-layer reserves, it is necessary to reasonably split the investment costs of shared facilities (drilling and surface facilities).

[0003] The "QSY 01180-2020 Specification for Evaluation of Economically Recoverable Reserves of Petroleum and Natural Gas" stipulates: "For special cases such as shared facilities (drilling and surface facilities), the economic evaluation can split the investment according to actual conditions, and provide splitting principles and methods." However, the specification does not give an exact method for splitting the investment cost.

[0004] In actual work, the commonly used method in the past was to split the reservoir according to the thickness. The advantage of this method is that it is simple and quick to operate. However, for tight sandstone gas reservoirs, the thickness of different gas-bearing strata often varies greatly, and the gas production capacity of the reservoir is not necessarily well correlated with the thickness of the reservoir. Simply splitting by reservoir thickness will cause the low-production layer to bear a higher investment cost, resulting in uneconomical single-layer evaluation and loss of reserves. When there is gas production profile data, the gas production profile test data can also be used for splitting. The advantage of this method is that it is easy to use, can well reflect the gas production capacity of the reservoir, and the results are more reasonable. However, in the exploration stage, there is little gas production profile test data, and in the development stage, it is difficult to fully cover the test layer due to the limitation of the wellbore string. Summary of the invention

[0005] The purpose of the present invention is to provide a method for splitting the investment cost of a multi-layer tight sandstone gas reservoir, which solves the problem that the existing method is uneconomical for single-layer evaluation, resulting in reserve loss, and the problem that when splitting the investment cost based on gas production profile data, it cannot be calculated due to lack of data.

[0006] The technical solution adopted by the present invention is: a method for splitting the investment cost of multi-layer tight sandstone gas reservoirs. By collecting data of the blocks to be evaluated, the relationship between the gas test data and the energy storage coefficient is established, the energy storage coefficient is corrected, and the gas production contribution rate of each layer is calculated based on the corrected energy storage coefficient. Based on the gas production contribution rate, the investment cost of the multi-layer shared facilities is split.

[0007] The technical solution adopted by the present invention is also characterized in that:

[0008] Furthermore, the method for splitting the investment cost of a multi-layer tight sandstone gas reservoir is specifically implemented in the following steps:

[0009] Step 1: Collect the production data of each layer at the test wellhead of the block to be evaluated, the total investment cost M of the shared facilities, and the energy storage coefficient of each layer data;

[0010] Step 2: Calculate the open flow rate Q of each layer using the gas test wellhead production data collected in step 1 n ;

[0011] Step 3: Subtract the unimpeded flow rate Q calculated in step 2 from n The energy storage coefficient collected in step 1 Perform fitting analysis and establish the unobstructed flow rate Q of each layer n Energy storage coefficient The coefficient of the fitting relationship is the unit energy storage coefficient capacity A of each layer. n ;

[0012] Step 4: calculate the unit energy storage coefficient capacity A of each layer calculated in step 3 n Perform standardization to obtain the standardized unit energy storage coefficient capacity of each layer

[0013] Step 5: Use step 4 to obtain the standardized unit energy storage coefficient capacity of each layer and the energy storage coefficient of each layer Calculate the corrected energy storage coefficient K of each layer n ;

[0014] Step 6: Use the corrected energy storage coefficient K of each layer obtained in step 5 n Calculate the gas production contribution rate G of each layer n ;

[0015] Step 7: Based on the gas production contribution rate G of each layer calculated in step 6 n , split the total shared facility investment cost M into single-layer investment cost m n .

[0016] Furthermore, the wellhead production data in step 1 includes the single-layer gas production q n and oil pressure P T .

[0017] Furthermore, in step 2, the “one-point method” is used to calculate the unobstructed flow rate Q n , calculated according to formula (1):

[0018]

[0019] Where: Q n : Single-layer unimpeded flow, q n: Single layer gas production, P T : Oil pressure.

[0020] Furthermore, the open-flow capacity Qn and energy storage coefficient in step 3 Linear regression analysis is performed to establish the linear regression equation of open flow and energy storage coefficient, as shown in formula (2):

[0021]

[0022] Among them, A n is the unit energy storage coefficient capacity of each layer.

[0023] Furthermore, in step 4, the linear proportional method is used to calculate the unit energy storage coefficient capacity A of each layer. n Perform standardization, as shown in formula (3):

[0024]

[0025] in, A n The dimensionless data, i.e. the standardized unit energy storage coefficient capacity of each layer, A n A is the unit energy storage coefficient capacity of each layer, min It is the minimum value of the unit energy storage coefficient capacity of each layer, and the minimum value of dimensionless data is 1.

[0026] Furthermore, the corrected energy storage coefficient K in step 5 n Calculated by formula (4):

[0027]

[0028] Among them, K n is the corrected energy storage coefficient of each layer.

[0029] Furthermore, the gas production contribution rate G of each layer in step 6 n Calculated by formula (5):

[0030]

[0031] Among them, K1, K2, ..., K n is the corrected energy storage coefficient of each layer.

[0032] Further, step 7 single-layer investment cost m n Calculated by formula (6):

[0033] m n =G n ×M (6)

[0034] Among them, m n is the single-layer investment cost, G nis the gas production contribution rate of each layer, and M is the total investment cost of shared facilities.

[0035] The beneficial effects of the present invention are:

[0036] The multi-layer tight sandstone gas reservoir investment cost splitting method of the present invention can effectively solve the problems that when the investment cost is split according to the reservoir thickness, single-layer evaluation is not economical, resulting in reserve loss, and when the investment cost is split according to the gas production profile data, the investment cost cannot be calculated due to lack of data.

[0037] The multi-layer tight sandstone gas reservoir investment cost splitting method of the present invention establishes the relationship between gas test data and energy storage coefficient, corrects the energy storage coefficient, and calculates the gas production contribution rate of each layer based on the corrected energy storage coefficient; the gas production contribution rate can effectively reflect the relative gas production capacity of each layer, and based on the gas production contribution rate, the investment cost of shared facilities (drilling and ground facilities) can be reasonably split. The cost splitting method of the present invention can achieve a result similar to the gas production profile, realizing the replacement of the gas production profile method. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] Figure 1 is a flow chart of the method of the present invention;

[0039] Figure 2 This is a fitting relationship diagram of open-flow capacity and energy storage coefficient in Example 1 of the present invention;

[0040] Figure 3 This is a fitting relationship diagram of open-flow capacity and energy storage coefficient in Example 2 of the present invention;

[0041] Figure 4 This is a fitting relationship diagram of open-flow capacity and energy storage coefficient in Example 3 of the present invention;

[0042] Figure 5 This is a fitting relationship diagram between the open-flow rate and the energy storage coefficient of Example 4 of the present invention. DETAILED DESCRIPTION

[0043] In order to make the purpose, technical solution and advantages of the present invention clearer and more understandable, the technical solution of the present invention will be clearly and completely described below in conjunction with the accompanying drawings.

[0044] The present invention discloses a method for splitting the investment cost of a multi-layer tight sandstone gas reservoir. The method collects data of a block to be evaluated, establishes a relationship between gas test data and an energy storage coefficient, and corrects the energy storage coefficient; the gas production contribution rate of each layer is calculated based on the corrected energy storage coefficient; the gas production contribution rate can effectively reflect the relative gas production capacity of each layer, and based on the gas production contribution rate, a reasonable splitting of the investment cost of shared facilities (drilling and ground facilities) is achieved.

[0045] like Figure 1As shown, the specific approach includes the following steps:

[0046] Step 1: Collect the production data of each layer at the test wellhead of the block to be evaluated, the total investment cost M of the shared facilities, and the energy storage coefficient of each layer Data, wellhead production data including single layer gas production q n and oil pressure P T Compared with other data, gas test data is easy to obtain, the information is relatively complete, there is a lot of room for operation, and the gas test data can reflect the reserves of the gas layer;

[0047] Step 2: Calculate the open flow rate Q of each layer using the gas test wellhead production data collected in step 1 n ; Compared with the test wellhead production, the open flow rate is not affected by the artificial working system, and can better characterize the production capacity of each layer and evaluate the gas production capacity between layers; there are many ways to calculate the open flow rate, which can be selected according to the actual situation;

[0048] Calculate the unobstructed flow rate Q using the "one point method" n , calculated according to formula (1):

[0049]

[0050] Where: Q n : Single-layer unimpeded flow, q n : Single layer gas production, P T : Oil pressure;

[0051] Step 3: Subtract the unimpeded flow rate Q calculated in step 2 from n The energy storage coefficient collected in step 1 Perform fitting analysis to establish the open-flow capacity Qn and energy storage coefficient of each layer The coefficient of the fitting relationship is the unit energy storage coefficient capacity A of each layer. n ;

[0052] Open flow Qn and energy storage coefficient Linear regression analysis is performed to establish a linear regression equation for open flow and energy storage coefficient, as shown in formula (2):

[0053]

[0054] Among them, A n is the capacity per unit energy storage coefficient of each layer;

[0055] Step 4: calculate the unit energy storage coefficient capacity A of each layer calculated in step 3 n Perform standardization to obtain the standardized unit energy storage coefficient capacity of each layer

[0056] The linear proportional method is used to calculate the unit energy storage coefficient capacity A of each layer. n Perform standardization, as shown in formula (3):

[0057]

[0058] in, A n The dimensionless data, i.e. the standardized unit energy storage coefficient capacity of each layer, A n A is the unit energy storage coefficient capacity of each layer, min It is the minimum value of the unit energy storage coefficient capacity of each layer, and the minimum value of dimensionless data is 1;

[0059] Step 5: Use step 4 to obtain the standardized unit energy storage coefficient capacity of each layer and the energy storage coefficient of each layer Calculate the corrected energy storage coefficient K of each layer n ;

[0060] Corrected energy storage coefficient K n Calculated by formula (4):

[0061]

[0062] Among them, K n is the corrected energy storage coefficient of each layer;

[0063] Step 6: Use the corrected energy storage coefficient K of each layer obtained in step 5 n Calculate the gas production contribution rate G of each layer n ;

[0064] Gas production contribution rate G of each layer n Calculated by formula (5):

[0065]

[0066] Among them, K1, K2, ..., K n is the corrected energy storage coefficient of each layer;

[0067] Step 7: Based on the gas production contribution rate G of each layer calculated in step 6 n , split the total shared facility investment cost M into single-layer investment cost m n ;

[0068] Single-layer investment cost m n Calculated by formula (6):

[0069] m n =G n ×M (6)

[0070] Among them, m nis the single-layer investment cost, G n is the gas production contribution rate of each layer, and M is the total investment cost of shared facilities.

[0071] The present invention provides a method for splitting the investment cost of a multi-layer tight sandstone gas reservoir. The method establishes a relationship between gas test data and the energy storage coefficient, corrects the energy storage coefficient, and calculates the gas production contribution rate of each layer based on the corrected energy storage coefficient; based on the gas production contribution rate, the investment cost of multi-layer shared facilities (drilling and ground facilities) is split.

[0072] In order to make the purpose, technical solution and key points of the present invention clearer, the specific implementation of the present invention is further described below in conjunction with the accompanying drawings and embodiments.

[0073] Example 1

[0074] (1) Collect the gas test data of all wells in the He 8 and Ma 5 1+2 layers of the Shenmu gas field and organize them by single well and single layer;

[0075] (2) Calculate the open flow rate using the test gas wellhead production data; This embodiment uses the "one-point method" empirical formula to calculate the open flow rate, and the formula is:

[0076] (3) Establish the unimpeded flow and energy storage coefficient through fitting analysis Taking Box 8 of Shenmu Gas Field as an example, through fitting analysis, the relationship between open flow and energy storage coefficient is obtained as follows: Then the unit energy storage coefficient of box 8 is 9.926, such as Figure 2 As shown;

[0077] (4) Based on the unit energy storage coefficient production capacity, the energy storage coefficient is standardized to obtain a corrected energy storage coefficient; this embodiment takes the Shenmu gas field S327 well as an example, and the well produces two layers, Box 8 and Ma Wu 1+2; the unit energy storage coefficient production of Box 8 and Ma Wu 1+2 obtained in step 3 is 9.926 and 37.718 respectively. Based on this, the energy storage coefficient is standardized to obtain a corrected energy storage coefficient, and the results are shown in Table 2;

[0078] (5) Calculating the gas production contribution rate of each layer using the corrected energy storage coefficient; Based on the corrected energy storage coefficient obtained in step 4, the gas production contribution rate of each layer is calculated respectively, and the calculation results are shown in Table 1;

[0079] Table 1 Calculation results of energy storage coefficient correction and gas production contribution rate

[0080]

[0081] (6) Based on the gas production contribution rate of each layer, the investment cost of shared facilities (drilling and surface facilities) is split into single-layer investment costs.

[0082] Embodiment 2:

[0083] (1) Collect the gas test data of all ancient wells in the Sulige gas field and organize them according to single well and single layer;

[0084] (2) Using the test gas wellhead production data, the open-flow rate is calculated using the "one-point method" empirical formula:

[0085] (3) Establish the open flow and energy storage coefficient through linear regression analysis Taking Box 8 of Sulige Gas Field as an example, through fitting analysis, the relationship between open flow and energy storage coefficient is obtained as follows: Then the unit energy storage coefficient of box 8 is 8.919, such as Figure 3 As shown;

[0086] (4) Based on the unit energy storage coefficient capacity, the energy storage coefficient is standardized to obtain a corrected energy storage coefficient; this embodiment takes the S40 well in the Sulige gas field as an example, and the well simultaneously produces three layers: Box 8, Mountain 1, and Mountain 2; the unit energy storage coefficient capacities of Box 8, Mountain 1, and Mountain 2 obtained in step 3 are 8.919, 9.508, and 9.0269, respectively. Based on this, the energy storage coefficient is standardized to obtain a corrected energy storage coefficient, and the results are shown in Table 3;

[0087] (5) Calculating the gas production contribution rate of each layer using the corrected energy storage coefficient; Based on the corrected energy storage coefficient obtained in step 4, the gas production contribution rate of each layer is calculated respectively, and the calculation results are shown in Table 2;

[0088] Table 2 Calculation results of energy storage coefficient correction and gas production contribution rate

[0089]

[0090]

[0091] (6) Based on the gas production contribution rate of each layer, the investment cost of shared facilities (drilling and surface facilities) is split into single-layer investment costs.

[0092] Embodiment 3:

[0093] (1) Collect the gas test data of all ancient wells in the Jingbian gas field and organize them according to single well and single layer;

[0094] (2) Using the test gas wellhead production data, the open flow rate is calculated using the "one-point method" empirical formula, and the formula is:

[0095] (3) Establish the open flow and energy storage coefficient through linear regression analysis Taking Box 8 of Jingbian gas field as an example, the relationship between open flow and energy storage coefficient is obtained through fitting analysis: Then the unit energy storage coefficient of box 8 is 9.926, such as Figure 4 As shown;

[0096] (4) Based on the unit energy storage coefficient capacity, the energy storage coefficient is standardized to obtain the corrected energy storage coefficient; this example takes the S356 well in the Jingbian gas field as an example. The well produces He 8, Shan 1, Shan 2, and Ma Wu at the same time. 1+2 、Ma 54 1 , Ma Wu 5 six layers; step 3 gets box 8, mountain 1, mountain 2, Ma Wu 1+2 、Ma 54 1 The unit energy storage coefficient capacities of , Mawu5 are 9.928, 12.145, 11.887, 37.718, 72.479, and 50.86, respectively. Based on this, the energy storage coefficient is standardized to obtain the corrected energy storage coefficient, and the results are shown in Table 4;

[0097] (5) Calculating the gas production contribution rate of each layer using the corrected energy storage coefficient; Based on the corrected energy storage coefficient obtained in step 4, the gas production contribution rate of each layer is calculated respectively, and the calculation results are shown in Table 3;

[0098] Table 3 Calculation results of energy storage coefficient correction and gas production contribution rate

[0099]

[0100] (6) Based on the gas production contribution rate of each layer, the investment cost of shared facilities (drilling and surface facilities) is split into single-layer investment costs.

[0101] Example 4

[0102] (1) Collect gas testing data from all ancient wells in Shenmu Gas Field and organize them by single well and single layer;

[0103] (2) Calculate the open flow rate using the test gas wellhead production data; This embodiment uses the "one-point method" empirical formula to calculate the open flow rate, and the formula is:

[0104] (3) Establish the unimpeded flow and energy storage coefficient through fitting analysis Taking Box 8 of Shenmu Gas Field as an example, through fitting analysis, the relationship between open flow and energy storage coefficient is obtained as follows: Then the unit energy storage coefficient of box 8 is 5.5667, such as Figure 2 As shown;

[0105] (4) Based on the unit energy storage coefficient production capacity, the energy storage coefficient is standardized to obtain a corrected energy storage coefficient; in this embodiment, the Shenmu gas field S416 well is taken as an example, and the well simultaneously produces five layers: Box 8, Mountain 1, Mountain 2, Taiyuan and Benxi; Step 3 obtains that the unit energy storage coefficient production of Box 8, Mountain 1, Mountain 2, Taiyuan and Benxi are 5.5667, 5.8015, 13.445, 7.5543 and 29.026 respectively. Based on this, the energy storage coefficient is standardized to obtain a corrected energy storage coefficient, and the results are shown in Table 4;

[0106] (5) Calculating the gas production contribution rate of each layer using the corrected energy storage coefficient; Based on the corrected energy storage coefficient obtained in step 4, the gas production contribution rate of each layer is calculated respectively, and the calculation results are shown in Table 4;

[0107] Table 4 Calculation results of energy storage coefficient correction and gas production contribution rate

[0108]

[0109]

[0110] (6) Based on the gas production contribution rate of each layer, the investment cost of shared facilities (drilling and surface facilities) is split into single-layer investment costs.

[0111] As mentioned above, the gas production profile test data can well reflect the production capacity of the reservoir. By comparing the gas production contribution rate obtained based on the gas production profile test data and the present invention, the present invention can achieve a result similar to the gas production profile, as shown in Table 5.

[0112] Table 5 Comparison of calculation results of gas production contribution rate

[0113]

[0114] It can be seen that the use of the present invention can achieve a replacement for the gas production profile method, and effectively solve the problem caused by the lack of gas production profile data.

[0115] The present invention provides a multi-layer tight sandstone gas reservoir investment cost splitting method, which establishes a relationship between gas test data and energy storage coefficient, corrects the energy storage coefficient, and calculates the gas production contribution rate of each layer based on the corrected energy storage coefficient. The gas production contribution rate can effectively reflect the relative gas production capacity of each layer, and the investment cost of shared facilities (drilling and ground facilities) can be reasonably split based on the gas production contribution rate. The present invention can achieve a result similar to the gas production profile, and realizes the replacement of the gas production profile method.

Claims

1. A method for splitting the investment cost of a multi-layer tight sandstone gas reservoir, characterized in that: By collecting data on the blocks to be evaluated, the relationship between the gas test data and the energy storage coefficient is established, the energy storage coefficient is corrected, and the gas production contribution rate of each layer is calculated based on the corrected energy storage coefficient. Based on the gas production contribution rate, the investment cost of multi-layer shared facilities is split.

2. The method for splitting the investment cost of a multi-layer tight sandstone gas reservoir according to claim 1, characterized in that: Please follow the steps below to implement: Step 1: Collect the production data of each layer at the test wellhead of the block to be evaluated, the total investment cost M of the shared facilities, and the energy storage coefficient of each layer data; Step 2: Calculate the open flow rate Q of each layer using the gas test wellhead production data collected in step 1 n ; Step 3: Subtract the unimpeded flow rate Q calculated in step 2 from n The energy storage coefficient collected in step 1 Perform fitting analysis and establish the unobstructed flow rate Q of each layer n Energy storage coefficient The coefficient of the fitting relationship is the unit energy storage coefficient capacity A of each layer. n ; Step 4: calculate the unit energy storage coefficient capacity A of each layer calculated in step 3 n Perform standardization to obtain the standardized unit energy storage coefficient capacity of each layer Step 5: Use step 4 to obtain the standardized unit energy storage coefficient capacity of each layer and the energy storage coefficient of each layer Calculate the corrected energy storage coefficient K of each layer n ; Step 6: Use the corrected energy storage coefficient K of each layer obtained in step 5 n Calculate the gas production contribution rate G of each layer n ; Step 7: Based on the gas production contribution rate G of each layer calculated in step 6 n , split the total shared facility investment cost M into single-layer investment cost m n .

3. The method for splitting the investment cost of a multi-layer tight sandstone gas reservoir according to claim 2, characterized in that: The wellhead production data in step 1 includes the single-layer gas production q n and oil pressure P T .

4. The method for splitting the investment cost of a multi-layer tight sandstone gas reservoir according to claim 3, characterized in that: In step 2, the "one point method" is used to calculate the unobstructed flow rate Q n , calculated according to formula (1): in: n : Single-layer unimpeded flow, q n : Single layer gas production, P T : Oil pressure.

5. The method for splitting the investment cost of a multi-layer tight sandstone gas reservoir according to claim 2, characterized in that: The unimpeded flow rate Q in step 3 n Energy storage coefficient Linear regression analysis is performed to establish a linear regression equation for open flow and energy storage coefficient, as shown in formula (2): Among them, A n is the unit energy storage coefficient capacity of each layer.

6. The method for splitting the investment cost of a multi-layer tight sandstone gas reservoir according to claim 2, characterized in that: In step 4, the linear proportional method is used to calculate the unit energy storage coefficient capacity A of each layer. n Perform standardization, as shown in formula (3): in, A n The dimensionless data, i.e. the standardized unit energy storage coefficient capacity of each layer, A n A is the unit energy storage coefficient capacity of each layer, min It is the minimum value of the unit energy storage coefficient capacity of each layer, and the minimum value of dimensionless data is 1.

7. The method for splitting the investment cost of a multi-layer tight sandstone gas reservoir according to claim 2, characterized in that: The corrected energy storage coefficient K in step 5 n Calculated by formula (4): Among them, K n is the corrected energy storage coefficient of each layer.

8. The method for splitting the investment cost of a multi-layer tight sandstone gas reservoir according to claim 2, characterized in that: The gas production contribution rate G of each layer in step 6 n Calculated by formula (5): Among them, K1, K2, ..., K n is the corrected energy storage coefficient of each layer.

9. The method for splitting the investment cost of a multi-layer tight sandstone gas reservoir according to claim 2, characterized in that: The single-layer investment cost of step 7 is m n Calculated by formula (6): m n =G n ×M (6) Among them, m n is the single-layer investment cost, G n is the gas production contribution rate of each layer, and M is the total investment cost of shared facilities.

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