Quantitative calculation method of interlayer interference coefficient of single well productivity in multi-layer commingled production reservoirs

Abstract

The present invention provides a quantitative calculation method for the interlayer interference coefficient of the productivity of a single well in the commingled production of multi-layer oil reservoirs, which belongs to the technical field of oil and gas field exploration and development, and includes the following steps: based on well logging parameters, determining the number of oil layers developed in the single well of the research object and the thickness and permeability of each oil layer; sorting the multi-layer oil reservoirs according to the permeability; decomposing the interference problem of the commingled production of multi-layer oil reservoirs into multiple interference problems between two-layer oil reservoirs; establishing a relationship between the interlayer interference coefficient of the commingled production of two-layer oil reservoirs and the permeability difference; calculating the interference coefficient between the two-layer oil reservoirs; calculating the total interference coefficient of each layer; and calculating the interlayer interference coefficient of the productivity of a single well in the commingled production of multi-layer oil reservoirs of the research object. The present invention converts the interlayer interference problem of the productivity of a single well in the commingled production of multi-layer oil reservoirs into the interlayer interference problem of the productivity of a single well in the commingled production of multiple two-layer oil reservoirs, and realizes the quantitative calculation of the interlayer interference coefficient of the productivity of a single well in the commingled production of multi-layer oil reservoirs under any number of layers and any thickness, and the calculation result is more real and reliable.

Description

Technical Field

[0001] The invention belongs to the technical field of oil and gas field exploration and development, and in particular relates to a method for quantitatively calculating an interlayer interference coefficient of productivity of a single well in a multi-layer commingled production oil reservoir. Background Art

[0002] Offshore oilfields are constrained by exploration and development costs and often adopt large well spacing and multi-layer commingled production methods. During multi-layer commingled production, due to the differences in thickness and physical properties of the vertical layers, interlayer interference is serious. Determining the interlayer interference coefficient of the productivity of a single well in multi-layer commingled production can effectively guide the evaluation of oil well productivity and the division of development strata, and is of great and practical significance for guiding the efficient development of offshore oilfields.

[0003] At present, the main methods for calculating the interlayer interference coefficient of the production capacity of a single well in a multi-layer commingled production reservoir include analogy and experimental methods. The analogy method is the main means of calculating the interlayer interference coefficient of the production capacity of a single well in a multi-layer commingled production reservoir. However, this method is a qualitative evaluation. Different technicians choose different analogy objects and standards during the analogy process, which affects the calculation results. The experimental method has the characteristics of accurate calculation, but it also has the characteristics of high experimental cost. At the same time, in the actual application of the multi-layer interlayer interference coefficient, due to the cost constraints of the experiment, it is impossible to carry out interlayer interference simulation experiments under any number of layers and any thickness. In the end, only results similar to the simulated experimental conditions can be found for application. Therefore, there is a problem of inconsistency between experimental conditions and application conditions in the actual application process. Therefore, it is urgent to establish a method for calculating the interlayer interference coefficient of the production capacity of a single well in a multi-layer commingled production reservoir to guide the determination of a reasonable interlayer interference coefficient of the production capacity of a single well in a multi-layer commingled production reservoir. To this end, the applicant designed a quantitative calculation method for the interlayer interference coefficient of the production capacity of a single well in a multi-layer commingled production reservoir to solve the above technical problems. Summary of the Invention

[0004] In view of this, the present invention aims to propose a method for quantitatively calculating the inter-layer interference coefficient of the productivity of a single well in a multi-layer oil reservoir, so as to solve the technical problem of quantitatively calculating the inter-layer interference coefficient of the productivity of a single well in a multi-layer oil reservoir, and to guide the technical problem of quantitatively calculating the inter-layer interference coefficient of the productivity of a single well in a multi-layer oil reservoir.

[0005] To achieve the above object, the technical solution of the present invention is implemented as follows: a method for quantitatively calculating the interlayer interference coefficient of the productivity of a single well in a multi-layer oil reservoir commingled production, comprising the following steps:

[0006] The first step is to determine the number of oil layers developed in a single well of the research object and the thickness and permeability of each oil layer based on the well logging parameters;

[0007] The second step is to sort the multi-layer reservoirs according to their permeability;

[0008] The third step is to decompose the interference problem of multi-layer reservoir commingling into the problem of interference between multiple two-layer reservoirs;

[0009] The fourth step is to establish the relationship between the interference coefficient and the permeability difference between the two layers of oil reservoirs;

[0010] Step 5: Calculate the interference coefficient between the two reservoirs;

[0011] Step 6: Calculate the total interference coefficient of each layer;

[0012] The seventh step is to calculate the inter-layer interference coefficient of the production capacity of a single well in the multi-layer oil reservoir of the research object.

[0013] Furthermore, the first step includes, based on the logging parameters, first conducting logging interpretation for the single well of the research object, determining which layers of the well point encounter oil layers, determining the thickness and permeability of the encountered oil layers, and then determining the number of oil layers developed in the single well of the research object and the thickness and permeability of each oil layer according to the perforation principles of oil field development.

[0014] Furthermore, the second step includes that n represents the number of oil layers developed by a single well of the research object, and after sorting, the first layer represents the layer with the first permeability, the second layer represents the layer with the second permeability, and so on.

[0015] Furthermore, the third step includes using the enumeration method to decompose the interference problem of multi-layer oil reservoir co-production into the interference problem between two layers of oil reservoirs. The first layer is not interfered with by any layer. The first layer interferes with n-1 layers, namely the second layer, the third layer, and up to the nth layer. The second layer is interfered with by the first layer. The second layer interferes with n-2 layers, namely the third layer, the fourth layer, and up to the nth layer. And so on. The nth layer is interfered with by the first layer to the n-1 layer, and the nth layer does not interfere with other layers. According to the enumeration method, the interference problem of n-layer oil reservoir co-production can be decomposed into n(n-1) / 2 combinations of interference problems between two layers of oil reservoirs.

[0016] Furthermore, the fourth step includes setting up multiple groups of two core single displacement experiments and parallel displacement experiments under different permeability differences, wherein the minimum value of the permeability difference is 1, and the maximum value of the permeability difference is greater than the ratio of the maximum permeability to the minimum permeability of the single layer of the single well development of the research object. According to the scheme design, an experimental study on the interference coefficient of the combined production of two layers of oil reservoirs under different permeability differences is carried out. First, a certain production injection and production pressure difference is set to separately displace the two cores, and the flow data of the two cores under stable conditions are recorded. Then, the two cores are connected in parallel, and the same injection and production pressure difference is used to carry out displacement. The flow data of the two cores under stable conditions are recorded, and the interlayer interference coefficient under each permeability difference is calculated. Its mathematical expression is:

[0017]

[0018] Where, α kis the interference coefficient between two layers of reservoirs with different permeability differences, l b is the stable flow rate of the low permeability core when two cores are flooded in parallel, ml / min; l c The steady flow rate of the low permeability core when the two cores were flooded separately, ml / min;

[0019] Then build α k The relationship between permeability difference and permeability difference is as follows:

[0020]

[0021] Where k h1 is the permeability difference; k high is the permeability of the high permeability core, mD; k low is the permeability of the low permeability core, millidarcy.

[0022] Furthermore, the fifth step includes that the interference coefficient of the two reservoir layers is affected not only by the permeability difference but also by the thickness difference. Therefore, the concept of thickness difference is introduced. The mathematical expression of thickness difference is:

[0023]

[0024] Where h h1 is the thickness difference; h high is the thickness of the hyperpermeable layer, m; h low is the thickness of the low permeability layer, m;

[0025] The mathematical expression of the interference coefficient between two reservoir layers considering the thickness is:

[0026]

[0027] Formula (4) is used to calculate the interlayer interference coefficient between the n(n-1) / 2 two-layer reservoirs obtained by the third step decomposition.

[0028] Furthermore, in the sixth step, the expression for the total interference coefficient of the jth layer is defined as α klj , define the interference coefficient of the i-th layer to the j-th layer as α klij From the third step, we can see that the first layer is not disturbed by any layer, and its total interference coefficient α kl1 The value of is 1, the second layer is interfered by the first layer, and its total interference coefficient α kl2 The value of α kl12 , and so on, the nth layer is interfered by the 1st layer to the n-1th layer, and its total interference coefficient α kln The mathematical expression is In summary, the total interference coefficient α of the jth layer kljThe mathematical expression is:

[0029]

[0030] Furthermore, in the seventh step, the expression of the interlayer interference coefficient of the production capacity of a single well in the multi-layer oil reservoir of the research object is defined, and its physical meaning is the sum of the formation coefficients of all layers and the total interference coefficient α of the layer. klj The weighted average of is expressed as:

[0031]

[0032] Where k j is the permeability of the jth layer, mD; h j is the thickness of the jth layer, meters; k j h j is the formation coefficient of the jth layer, mD·m.

[0033] Compared with the prior art, the quantitative calculation method of the interlayer interference coefficient of the productivity of a single well in a multi-layer commingled production reservoir described in the present invention has the following advantages:

[0034] (1) The method of the present invention decomposes the interference problem of multi-layer commingled production into multiple interference problems between two layers of oil reservoirs in the third step. Then, the interference coefficient of each disturbed layer is calculated by combining the interference coefficients of the two layers of oil reservoirs calculated in the fourth and fifth steps of the present application. Finally, the interference coefficient of the production capacity of a single well in a multi-layer commingled production oil reservoir is determined, thereby achieving quantitative calculation of the interference coefficient between commingled production layers of any multi-layer oil reservoir. This solves the problem of different technicians selecting analog objects and inconsistent standards caused by qualitative evaluation by analogy method.

[0035] (2) The method of the present invention only requires conducting two-layer interlayer interference experiments during the experiment, establishing the relationship between any multiple-layer interlayer interference and the two-layer interlayer interference, and ultimately achieving the characterization of any number of layers of multi-layer interlayer interference. The experimental cost is relatively low;

[0036] (3) The method of the present invention solves the problem that due to the cost constraints of the experiment, it is impossible to carry out interlayer interference simulation experiments with any number of layers and any thickness. Ultimately, only results similar to the simulation experimental conditions can be found for application, resulting in inconsistency between experimental conditions and application conditions.

[0037] (4) The method described in the present invention converts the inter-layer interference problem of the production capacity of a single well in the combined production of multiple oil reservoirs into the inter-layer interference problem of the production capacity of a single well in the combined production of multiple two-layer oil reservoirs. When calculating the inter-layer interference coefficient of the production capacity of a single well in the combined production of two-layer oil reservoirs, the difference in thickness between the high permeability layer and the low permeability layer is taken into account, thereby realizing the quantitative calculation of the inter-layer interference coefficient of the production capacity of a single well in the combined production of multiple oil reservoirs under any number of layers and any thickness, and the calculation result is more real and reliable. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] The accompanying drawings, which constitute part of the present invention, are provided to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are provided to explain the present invention and do not constitute an undue limitation of the present invention. In the accompanying drawings:

[0039] Figure 1 This is a flow chart of the method for quantitatively calculating the interlayer interference coefficient of the productivity of a single well in a multi-layer oil reservoir;

[0040] Figure 2 This is a diagram of the interlayer interference coefficient under different permeability differences. DETAILED DESCRIPTION

[0041] It should be noted that, in the absence of conflicts, the embodiments of the present invention and the features therein can be combined with each other. The present invention is a quantitative calculation method for the inter-layer interference coefficient of the productivity of a single well in a multi-layer oil reservoir co-production. The core invention point is: converting the inter-layer interference problem of the productivity of a single well in a multi-layer oil reservoir co-production into a plurality of inter-layer interference problems of the productivity of a single well in a two-layer oil reservoir co-production. When calculating the inter-layer interference coefficient of the productivity of a single well in a two-layer oil reservoir co-production, the difference in thickness between the high permeability layer and the low permeability layer is considered, thereby realizing the quantitative calculation of the inter-layer interference coefficient of the productivity of a single well in a multi-layer oil reservoir co-production under any number of layers and any thickness, and the calculation results are more real and reliable. It is rare to find a method that simultaneously considers the influence of permeability difference, inter-layer thickness difference and number of layers on inter-layer interference. The evaluation results of the present invention are more reasonable and reliable.

[0042] To better understand the content, features and objectives of the present invention, the following embodiments are given as examples and described in detail with reference to the accompanying drawings:

[0043] The specific implementation process of the method for quantitatively calculating the interlayer interference coefficient of the productivity of a single well in a multi-layer oil reservoir combined production according to the present invention is as follows: Figure 1 As shown:

[0044] The first step is to determine the number of oil layers developed by the single well under study, as well as the thickness and permeability of each oil layer, based on the well logging parameters. This includes: first, conducting well logging interpretation for the single well under study based on the well logging parameters to determine which layers of the well point encounter oil layers, as well as the thickness and permeability of the encountered oil layers. Then, based on the perforation principles of oilfield development, determine the number of oil layers developed by the single well under study, as well as the thickness and permeability of each oil layer.

[0045] In this example, Well X-1 in the Bohai Oilfield was selected. Based on well logging parameters, the thickness and permeability of the oil layers encountered throughout the entire well section of Well X-1 were determined, as shown in Table 1. As can be seen from Table 1, a total of 12 oil layers were encountered throughout the entire well section, with a total oil layer thickness of 51.1 m. Based on the perforation principles of oilfield development, the stratum developed by Well X-1 was determined to be the Shahejie Formation, and the number of developed oil layers was determined to be 6, namely X-1-7, X-1-8, X-1-9, X-1-10, X-1-11, and X-1-12.

[0046] Table 1 Thickness and permeability of oil layers encountered in Well X-1

[0047]

[0048] The second step is to sort the multi-layer reservoirs according to their permeability, where n represents the number of oil layers developed by a single well in the research object. After sorting, layer 1 represents the layer with the highest permeability, layer 2 represents the layer with the second highest permeability, and so on.

[0049] In this embodiment, the number of oil layers developed in the X-1 well is 6, the first layer is the X-1-9 layer, the second layer is the X-1-8 layer, the third layer is the X-1-12 layer, the fourth layer is the X-1-10 layer, the fifth layer is the X-1-7 layer, and the sixth layer is the X-1-11 layer.

[0050] The third step is to decompose the interference problem of multi-layer oil reservoir co-production into multiple interference problems between two layers of oil reservoirs. The enumeration method is used to decompose the interference problem of multi-layer oil reservoir co-production into the interference problem between two layers of oil reservoirs. The first layer is not interfered with by any layer. The first layer interferes with n-1 layers, namely the second layer, the third layer, and up to the nth layer. The second layer is interfered with by the first layer. The second layer interferes with n-2 layers, namely the third layer, the fourth layer, and up to the nth layer. And so on. The nth layer is interfered with by the first layer to the n-1 layer. The nth layer does not interfere with other layers. According to the enumeration method, the interference problem of n-layer oil reservoir co-production can be decomposed into n(n-1) / 2 combinations of interference problems between two layers of oil reservoirs.

[0051] The interlayer interference problem of the X-1 well in this embodiment belongs to the interference problem between 6 layers, which can be converted into the interference problem between multiple two-layer oil reservoirs. The X-1-9 layer is not interfered with by any layer. The X-1-9 layer interferes with the X-1-8 layer, the X-1-12 layer, the X-1-10 layer, the X-1-7 layer and the X-1-11 layer. The X-1-8 layer is interfered with by the X-1-9 layer. The X-1-8 layer interferes with the X-1-12 layer, the X-1-10 layer, the X-1-7 layer and the X-111 layer. The X-12 layer is interfered with by the X-18 layer and the X-19 layer. The X-1-10 layer, the X-1-7 layer and the X-1-11 layer, the X-1-10 layer is interfered with by the X-1-8 layer, the X-1-9 layer and the X-1-12 layer, the X-1-10 layer interferes with the X-1-7 layer and the X-1-11 layer, the X-1-7 layer is interfered with by the X-1-8 layer, the X-1-9 layer, the X-1-12 layer and the X-1-10 layer, the X-1-7 layer interferes with the X-1-11 layer, the X-1-11 layer is interfered with by the X-1-8 layer, the X-1-9 layer, the X-1-12 layer, the X-10 layer and the X-1-7 layer, the X-1-11 layer does not interfere with other layers.

[0052] The fourth step is to establish the relationship between the interlayer interference coefficient and the permeability difference of the two-layer oil reservoir co-production. Set up multiple groups of two core single displacement experiments and parallel displacement experiments under different permeability differences. The minimum value of the permeability difference is 1, and the maximum value of the permeability difference must be greater than the ratio of the maximum permeability to the minimum permeability of the single layer of the research object developed by the single well. According to the scheme design, the experimental study of the interlayer interference coefficient of the two-layer oil reservoir co-production under different permeability differences is carried out. First, set a certain production injection and production pressure difference to displace the two cores separately, record the flow data of the two cores under stable conditions, and then connect the two cores in parallel, use the same injection and production pressure difference to carry out displacement, and record the flow data of the two cores under stable conditions. Calculate the interlayer interference coefficient under each permeability difference, and its mathematical expression is:

[0053]

[0054] Where, α k is the interference coefficient between two layers of reservoirs with different permeability differences, l b is the stable flow rate of the low permeability core when two cores are flooded in parallel, ml / min; l c The steady flow rate of the low permeability core when the two cores were flooded separately, ml / min;

[0055] Then build α k The relationship between permeability difference and permeability difference is as follows:

[0056]

[0057] Where kh1 is the permeability difference; k high is the permeability of the high permeability core, mD; k low is the permeability of the low permeability core, millidarcy.

[0058] The relationship between the interlayer interference coefficient and the permeability difference is regressed according to the experimental results;

[0059] In this example, the first layer of the X-1 well is the X-1-9 layer, and the sixth layer is the X-1-11 layer. The maximum permeability difference between the layers is 8.02. Therefore, this example sets up 10 groups of two core single displacement experiments and parallel displacement experiments under different permeability differences. The permeability differences are 1, 2, 3, 4, 5, 6, 7, 8, 9 and 10 respectively. The interlayer interference coefficient under different permeability differences is as follows: Figure 2 As shown, according to Figure 2 The relationship between the interference coefficient and permeability difference between the two layers of oil reservoirs is established as follows:

[0060]

[0061] The fifth step is to calculate the interference coefficient between the two reservoir layers. The interference coefficient between the two reservoir layers is affected not only by the permeability difference but also by the thickness difference. Therefore, the concept of thickness difference is introduced. The mathematical expression of thickness difference is:

[0062]

[0063] Where h h1 is the thickness difference; h high is the thickness of the hyperpermeable layer, m; h low is the thickness of the low permeability layer, m;

[0064] The mathematical expression of the interference coefficient between two reservoir layers considering the thickness is:

[0065]

[0066] The interlayer interference coefficient between all two layers of oil reservoirs in this embodiment is calculated using formula (4).

[0067] In this embodiment, the first layer, X-1-9, is not interfered with by any other layer. The inter-layer interference coefficient of the second layer, X-1-8, interfered with by X-1-9, is 0.98. The inter-layer interference coefficients of the third layer, X-1-12, interfered with by X-1-8 and X-1-9, are 0.89 and 0.96, respectively. The inter-layer interference coefficients of the fourth layer, X-1-10, interfered with by X-1-8, X-1-9, and X-12, are 0.97, 0.99, and 1, respectively. 00, the inter-layer interference coefficients of the 5th layer X-1-7 affected by the interference of the X-1-8, X-1-9, X-1-12 and X-1-10 layers are 0.87, 0.94, 0.97 and 0.92 respectively, and the inter-layer interference coefficients of the 6th layer X-1-11 affected by the interference of the X-1-8, X-1-9, X-1-12, X-1-10 and X-1-7 layers are 0.69, 0.85, 0.93, 0.79 and 0.97 respectively.

[0068] The sixth step is to calculate the total interference coefficient of each layer and define the expression of the total interference coefficient of the jth layer as α klj , define the interference coefficient of the i-th layer to the j-th layer as α klij From the third step, we can see that the first layer is not disturbed by any layer, and its total interference coefficient α kl1 The value of is 1, the second layer is interfered by the first layer, and its total interference coefficient α kl2 The value of α kl12 , and so on, the nth layer is interfered by the 1st layer to the n-1th layer, and its total interference coefficient α kln The mathematical expression is In summary, the total interference coefficient α of the jth layer klj The mathematical expression is:

[0069]

[0070] The total interference coefficient of each layer of the X-1 well in this embodiment is calculated using formula (5), as shown in Table 2:

[0071] Table 2 Total interference coefficient of each layer in Well X-1

[0072]

[0073] The seventh step is to calculate the inter-layer interference coefficient of the production capacity of a single well in the multi-layer oil reservoir of the research object. The expression of the inter-layer interference coefficient of the production capacity of a single well in the multi-layer oil reservoir of the research object is defined as β, and its physical meaning is the sum of the formation coefficients of all layers and the total interference coefficient α of the layer. klj The weighted average of is expressed as:

[0074]

[0075] Where kj is the permeability of the jth layer, mD; h j is the thickness of the jth layer, meters; k j h j is the formation coefficient of the jth layer, mD·m.

[0076] The β value of the interlayer interference coefficient of the single-well productivity of multi-layer oil reservoir commingled production in Well X-1 in this embodiment is calculated using Formula (6) to be 0.92.

[0077] It will be understood that the present invention is described through some embodiments, which are known to those skilled in the art and are not intended to limit the present invention. Various changes or equivalent substitutions may be made to these features and embodiments without departing from the spirit and scope of the present invention. In addition, under the guidance of the present invention, these features and embodiments may be modified to adapt to specific circumstances and materials without departing from the spirit and scope of the present invention. Therefore, the present invention is not limited by the specific embodiments disclosed herein, and all embodiments that fall within the scope of the claims of this application are within the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A quantitative calculation method for the interlayer interference coefficient of the productivity of a single well in a multi-layer oil reservoir, characterized by: The following steps are involved: The first step is to determine the number of oil layers developed in a single well of the research object and the thickness and permeability of each oil layer based on the well logging parameters; The second step is to sort the multi-layer reservoirs according to their permeability; The third step is to decompose the interference problem of commingled production of multi-layer oil reservoirs into a plurality of interference problems between two layers of oil reservoirs. The third step includes using an enumeration method to decompose the interference problem of commingled production of multi-layer oil reservoirs into the interference problem between two layers of oil reservoirs, wherein the first layer is not interfered with by any layer, and the first layer interferes with n-1 layers, namely the second layer, the third layer, and up to the nth layer; the second layer is interfered with by the first layer, and the second layer interferes with n-2 layers, namely the third layer, the fourth layer, and up to the nth layer; and so on, the nth layer is interfered with by the first layer, up to the n-1 layer, and the nth layer does not interfere with other layers. According to the enumeration method, the interference problem of commingled production of n layers of oil reservoirs can be decomposed into n(n-1) / 2 combinations of interference problems between two layers of oil reservoirs. The fourth step is to establish the relationship between the interference coefficient of the two-layer combined production layer and the permeability difference; calculate the interference coefficient α of the two-layer combined production layer k and permeability difference, and regress the relationship between the interlayer interference coefficient and the permeability difference based on the experimental results; The fifth step is to calculate the interference coefficient between the two reservoirs; calculate the thickness difference by the thickness of the high permeability layer and the thickness of the low permeability layer, and then calculate the thickness difference and α k Calculate the interference coefficient between all two layers of oil reservoirs; The sixth step is to calculate the total interference coefficient of each layer; the total interference coefficient α of the jth layer klj The mathematical expression is: Where, α klij is the interference coefficient of the i-th layer to the j-th layer; In the seventh step, the interlayer interference coefficient of the production capacity of a single well in the multi-layer oil reservoir under study is calculated by taking the weighted average of the formation coefficients of all layers and the total interference coefficient of the layer.

2. The method for quantitatively calculating the interlayer interference coefficient of productivity of a single well in multi-layer oil reservoir commingled production according to claim 1 is characterized by: The first step includes, based on the logging parameters, firstly conducting logging interpretation for the single well of the research object, determining which layers of the well point encounter oil layers, determining the thickness and permeability of the encountered oil layers, and then determining the number of oil layers developed by the single well of the research object and the thickness and permeability of each oil layer according to the perforation principles of oil field development.

3. The method for quantitatively calculating the interlayer interference coefficient of productivity of a single well in multi-layer oil reservoir commingled production according to claim 1 is characterized by: The second step includes: n represents the number of oil layers developed by a single well of the research object, and after sorting, the first layer represents the layer with the highest permeability, the second layer represents the layer with the highest permeability, and so on.

4. The method for quantitatively calculating the interlayer interference coefficient of productivity of a single well in multi-layer oil reservoir commingled production according to claim 1 is characterized in that: The fourth step includes setting up multiple groups of two core single displacement experiments and parallel displacement experiments under different permeability differences, wherein the minimum value of the permeability difference is 1, and the maximum value of the permeability difference is greater than the ratio of the maximum permeability to the minimum permeability of the single layer of the single well development of the research object. According to the scheme design, an experimental study on the interference coefficient of the combined production of two layers of oil reservoirs under different permeability differences is carried out. First, a certain production injection and production pressure difference is set to separately displace the two cores, and the flow data of the two cores under stable conditions are recorded. Then, the two cores are connected in parallel and the same injection and production pressure difference is used to carry out displacement. The flow data of the two cores under stable conditions are recorded, and the interlayer interference coefficient under each permeability difference is calculated. The mathematical expression is: Where, α k is the interference coefficient between two layers of reservoirs with different permeability differences, l b is the stable flow rate of the low permeability core when two cores are flooded in parallel, ml / min; l c The steady flow rate of the low permeability core when the two cores were flooded separately, ml / min; Then build α k The relationship between permeability difference and permeability difference is as follows: Where k h1 is the permeability difference; k high is the permeability of the high permeability core, mD; k low is the permeability of the low permeability core, millidarcy.

5. The method for quantitatively calculating the interlayer interference coefficient of productivity of a single well in multi-layer oil reservoir commingled production according to claim 1 is characterized by: The fifth step includes that the interference coefficient of the two reservoir layers is affected not only by the permeability difference but also by the thickness difference. Therefore, the concept of thickness difference is introduced. The mathematical expression of thickness difference is: Where h h1 is the thickness difference; h high is the thickness of the hyperpermeable layer, m; h low is the thickness of the low permeability layer, m; The mathematical expression of the interference coefficient between two reservoir layers considering the thickness is: Formula (4) is used to calculate the interlayer interference coefficient between the n(n-1) / 2 two-layer reservoirs obtained by the third step decomposition.

6. The method for quantitatively calculating the interlayer interference coefficient of productivity of a single well in multi-layer oil reservoir commingled production according to claim 1 is characterized by: In the sixth step, the expression for the total interference coefficient of the jth layer is defined as α klj , define the interference coefficient of the i-th layer to the j-th layer as α klij From the third step, we can see that the first layer is not disturbed by any layer, and its total interference coefficient α kl1 The value of is 1, the second layer is interfered by the first layer, and its total interference coefficient α kl2 The value of α kl12 , and so on, the nth layer is interfered by the 1st layer to the n-1th layer, and its total interference coefficient α kln The mathematical expression is In summary, the total interference coefficient α of the jth layer klj The mathematical expression is:

7. The method for quantitatively calculating the interlayer interference coefficient of productivity of a single well in multi-layer oil reservoir commingled production according to claim 6 is characterized by: In the seventh step, the expression of the interlayer interference coefficient of the multi-layer oil reservoir single well production capacity of the research object is defined as β, whose physical meaning is the sum of the formation coefficient of all layers and the total interference coefficient α of the layer. klj The weighted average of is expressed as: Where k j is the permeability of the jth layer, mD; h j is the thickness of the jth layer, meters; k j h j is the formation coefficient of the jth layer, mD·m.

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