Complex fault block different type reservoir side drilling potential evaluation method, system, electronic equipment and computer readable storage medium

Abstract

This invention discloses a method, system, electronic device, and computer-readable storage medium for evaluating the sidetracking potential of different types of reservoirs in complex fault blocks. The method includes: determining the reservoir type; selecting evaluation indicators affecting the sidetracking potential of different reservoir types; establishing the weights of each evaluation indicator; determining the distribution of evaluation levels and the corresponding evaluation classification standards for each evaluation indicator in each evaluation level; establishing an unknown single-indicator measurement function; statistically analyzing the actual values ​​of each evaluation indicator for the target reservoir; determining the quantitative value of a single indicator; classifying the sidetracking potential levels based on the comprehensive evaluation of multiple indicators; and calculating the comprehensive score based on the comprehensive evaluation vector of multiple indicators and the assignment of evaluation space. This invention proposes the concept of evaluating sidetracking potential by reservoir type, accurately characterizing the size of the sidetracking potential of the target area, and compensating for the inaccurate potential evaluation when using the same parameters for reservoirs with different conditions; it also establishes an unknown single-indicator measurement function, realizing the hierarchical and quantitative analysis of geological parameters in the target area.

Description

Technical Field

[0001] This invention relates to the field of reservoir development technology, and more specifically, to a method, system, electronic device, and computer-readable storage medium for evaluating the sidetracking potential of complex fault-block reservoirs of different types. Background Technology

[0002] Currently, there is no unified technical methodology system, either domestically or internationally, for evaluating the sidetracking potential of different types of reservoirs. Using the same evaluation system for different types of reservoirs results in highly subjective and inaccurate evaluations. Furthermore, the magnitude of sidetracking potential is related to multiple factors, leading to significant uncertainty and increasing the difficulty of comprehensive evaluation.

[0003] Therefore, there is an urgent need to propose a method for evaluating the sidetracking potential of different types of reservoirs in complex fault blocks, establish a classification index system for evaluating the sidetracking potential of reservoirs, scientifically evaluate the sidetracking potential of different reservoirs, identify the main factors restricting the tapping of remaining oil potential in oilfields, and provide a basis for targeted sidetracking deployment in the next step. Summary of the Invention

[0004] The purpose of this invention is to provide a method, system, electronic device, and computer-readable storage medium for evaluating the sidetracking potential of different types of reservoirs in complex fault blocks, which can scientifically assess the sidetracking potential of different reservoirs and identify the main factors restricting the tapping of remaining oil in oil fields.

[0005] The first aspect of the present invention provides a method for evaluating the sidetracking potential of different types of reservoirs in complex fault blocks, including: step S1: determining the reservoir type, selecting evaluation indicators that affect the sidetracking potential of different types of reservoirs, and establishing the weight of each evaluation indicator;

[0006] Step S2: Determine the distribution of evaluation levels and the corresponding evaluation classification standards for each evaluation indicator in each evaluation level;

[0007] Step S3: Establish a single-index unknown measurement function, statistically analyze the actual values ​​of each evaluation index of the target reservoir; determine the quantitative value of each index;

[0008] Step S4: Based on a comprehensive evaluation of multiple indicators, classify the potential level of side-drilling;

[0009] Step S5: Calculate the comprehensive score based on the multi-index comprehensive evaluation vector and the evaluation space assignment.

[0010] Optionally, in step S1, the evaluation indicators that affect the sidetracking potential of different types of reservoirs include:

[0011] The evaluation indicators in the heavy oil reservoir sidetracking potential index system include: structural location coefficient, oil layer thickness, remaining recoverable reserves, comprehensive water cut, well pattern and spacing coefficient, carbon dioxide huff and puff cycles, and sidetracking cost, with a weight of W = (0.15, 0.1, 0.25, 0.1, 0.15, 0.1, 0.15).

[0012] The evaluation indicators in the sidetracking potential index system for light oil reservoirs include: structural location coefficient, oil layer thickness, remaining recoverable reserves, comprehensive water cut, well pattern and well spacing coefficient, pressure coefficient, and sidetracking cost, with a weight of W = (0.2, 0.1, 0.2, 0.1, 0.1, 0.1, 0.1, 0.1).

[0013] Optionally, the structural location coefficient refers to the ratio of the oil column height corresponding to the current elevation to the oil column height of the reservoir, based on the elevation relationship; Structural location coefficient = (target elevation - lowest elevation of the reservoir) / (highest elevation of the reservoir - lowest elevation of the reservoir).

[0014] And / or, oil layer thickness refers to the average thickness of oil layers encountered in adjacent wells;

[0015] And / or, the remaining recoverable reserves are calculated as geological reserves × rated recovery rate - cumulative oil production;

[0016] And / or, the comprehensive water content calculation method is the ratio of daily water production to daily liquid production;

[0017] And / or, the well spacing coefficient is the ratio of the absolute value of the difference between the straight distance between the target well and the adjacent well and the design optimal well spacing to the design optimal well spacing; well spacing coefficient = |(straight distance between the target well and the adjacent well - design optimal well spacing)| / design optimal well spacing;

[0018] And / or, the pressure coefficient is calculated as the ratio of the formation pressure in the target area to the original formation pressure;

[0019] And / or, the sidetracking cost calculation method is drilling cost + surface cost.

[0020] Optionally, step S3 further includes:

[0021] Establish a membership function to determine the quantified value of a single indicator.

[0022] Optionally, a membership function is established to determine the quantified value of a single indicator, including:

[0023] Establish one-factor unknown measure functions for each factor, and calculate and score each evaluation index.

[0024] Optionally, step S4: Based on a comprehensive evaluation of multiple indicators, the potential level for side-drilling is classified, including:

[0025] Establish a multi-indicator comprehensive evaluation. Based on the single-factor measurement matrix and indicator weights, calculate the multi-indicator comprehensive measure, using u... ik =u(x i ∈c k ) represents sample x i Belongs to c k The degree of the evaluation level is as follows:

[0026]

[0027] In the formula: u ijk To represent sample x i The single-factor measurement values ​​of the j-th evaluation index;

[0028] i is the i-th sample among 1 to n samples;

[0029] j is the j-th indicator among 1 to m indicators;

[0030] K is the kth evaluation level among 1-p evaluation levels;

[0031] i=1,2,…,n;j=1,2,…,m;k=1,2,…,p;

[0032] wj is the weight of the j-th indicator; u is determined by equation (5). ik It is an uncertain measure, and equation (6) is a multi-index comprehensive measure evaluation matrix; sample x i The multi-index comprehensive measurement evaluation vector is the i-th row vector (u) in equation (6). i1 u ik , ..., u ip );

[0033]

[0034] The membership degree of each sample at each evaluation level is calculated sequentially; the comprehensive evaluation matrix is ​​obtained by multiplying the weight coefficient with the multi-index comprehensive measurement matrix; the comprehensive evaluation level of each sample is determined according to the confidence principle; finally, the final scores are sorted by assigning values ​​according to the empirical formula.

[0035] Optionally, in step S5:

[0036] Overall Score Q Ai It is the product of a multi-indicator comprehensive measurement evaluation vector and the values ​​assigned to different evaluation levels;

[0037] Among them, the different evaluation levels are assigned values ​​of C1=4, C2=3, C3=2, and C4=1;

[0038] The multi-index comprehensive measurement and evaluation vector is sample x. i The multi-index comprehensive measurement evaluation vector is the i-th row vector (u) in equation (6).i1 u ik , ..., u ip );

[0039] Q Ai =μ i1 ×4+μ i2 ×3+μ i3 ×2+……+μ ip ×1

[0040] Evaluate multiple target regions A1, A2, ..., A i , ..., A n The target area is determined by assigning a score of Q to each target area. A1 Q A2 ...Q An By sorting the scores, the potential order of different target areas in the same oilfield can be obtained.

[0041] The second aspect of this invention discloses a sidetracking potential evaluation system for different types of complex fault-block reservoirs, the system comprising:

[0042] The first processing module is configured to determine the reservoir type, select evaluation indicators that affect the sidetracking potential of different types of reservoirs, and establish the weight of each evaluation indicator.

[0043] The second processing module is configured to determine the distribution of evaluation levels and the evaluation classification standards corresponding to each evaluation indicator in each evaluation level.

[0044] The third processing module is configured to: establish a single-index unknown measurement function; statistically analyze the actual values ​​of each evaluation index of the target reservoir; and determine the quantitative value of a single index.

[0045] The fourth processing module is configured to classify the potential level of side-drilling based on a comprehensive evaluation of multiple indicators.

[0046] The fifth processing module is configured to calculate the comprehensive score based on the multi-indicator comprehensive evaluation vector and the evaluation space assignment.

[0047] The third aspect of the present invention discloses an electronic device, which includes a memory and a processor. The memory stores a computer program, and when the processor executes the computer program, it implements the steps in the sidetracking potential evaluation method for complex fault block reservoirs of different types according to any one of the first aspects of the present invention.

[0048] The fourth aspect of the present invention discloses a computer-readable storage medium storing a computer program, which, when executed by a processor, implements the steps in the sidetracking potential evaluation method for complex fault block reservoirs of different types according to any one of the first aspects of the present invention.

[0049] According to the technical content disclosed in this invention, the following beneficial effects are achieved:

[0050] This invention provides a method that proposes the concept of evaluating sidetracking potential based on reservoir type, accurately characterizing the potential of the target area and overcoming the problem of inaccurate potential evaluation when using the same parameters for reservoirs with different conditions. It establishes a single-index, unknown measure function, achieving hierarchical and quantitative evaluation of geological parameters in the target area. The evaluation parameters are simple to obtain, the evaluation process is simple and easy to operate, and it has strong field applicability. The evaluation results can provide a basis for subsequent sidetracking deployment. It enables multi-factor quantitative evaluation of the sidetracking potential of different types of reservoirs in complex fault blocks and allows for targeted guidance on sidetracking potential tapping schemes for these reservoirs based on the evaluation results.

[0051] Other features and advantages of the invention will become clear from the following detailed description of exemplary embodiments of the invention with reference to the accompanying drawings. Attached Figure Description

[0052] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments of the invention and, together with their description, serve to explain the principles of the invention.

[0053] Figure 1 This is a flowchart of the method for evaluating the sidetracking potential of different types of reservoirs in complex fault blocks according to the present invention.

[0054] Figure 2 This is a hierarchical structure diagram of the reservoir sidetracking potential evaluation index system of the present invention.

[0055] Figure 3 This invention provides a single-index measurement function for undetermined heavy oil reservoir measurements.

[0056] Figure 4 The present invention provides a single-index measurement function for the unknown measurement of light oil reservoirs. Detailed Implementation

[0057] Various exemplary embodiments of the present invention will now be described in detail with reference to the accompanying drawings. It should be noted that, unless otherwise specifically stated, the relative arrangement, numerical expressions, and values ​​of the components and steps set forth in these embodiments do not limit the scope of the invention.

[0058] The following description of at least one exemplary embodiment is merely illustrative and is in no way intended to limit the invention or its application or use.

[0059] Techniques, methods, and equipment known to those skilled in the art may not be discussed in detail, but where appropriate, they should be considered part of the specification.

[0060] In all the examples shown and discussed herein, any specific values ​​should be interpreted as merely exemplary and not as limitations. Therefore, other examples of exemplary embodiments may have different values.

[0061] It should be noted that similar labels and letters in the following figures indicate similar items; therefore, once an item is defined in one figure, it does not need to be discussed further in subsequent figures.

[0062] See Figure 1 The first aspect of this invention discloses a method for evaluating the sidetracking potential of different types of reservoirs in complex fault blocks, including:

[0063] Step S1: Determine the reservoir type, select evaluation indicators that affect the sidetracking potential of different reservoir types, and establish the weight of each evaluation indicator;

[0064] The method for determining reservoir type is to differentiate reservoir types based on the different oil properties of complex fault-block reservoirs. Specifically, this is done by classifying reservoirs according to their fluid properties, dividing them into two categories: light oil reservoirs and heavy oil reservoirs. Light oil reservoirs are those with crude oil viscosity less than 50 mPa·s and relative density less than 0.92. Heavy oil reservoirs are those with crude oil viscosity greater than 50 mPa·s and relative density greater than 0.92 under reservoir conditions.

[0065] The method for establishing the weights of each evaluation index includes: establishing the weights of each evaluation index based on its influence on the sidetracking potential of different reservoirs. In specific implementation, since the factors affecting the sidetracking potential of complex fault-block reservoirs mainly include three categories of factors: reservoir geological parameters, reservoir development indicators, and economic benefit indicators, this embodiment of the invention proposes two concepts: structural location coefficient and well-grid coefficient. The structural location index is quantified, and the well-grid coefficient is introduced to normalize different well spacing positions, thus optimizing the sidetracking potential evaluation index system, improving the accuracy of sidetracking potential evaluation, and serving as an evaluation index for assessing the sidetracking potential of different types of complex fault-block reservoirs. Specifically, the structural location coefficient reflects the influence of structural location on the reservoir's sidetracking potential, while the well-grid coefficient characterizes the well network deployment during reservoir development.

[0066] Figure 2 This invention illustrates a hierarchical structure diagram of a sidetracking potential evaluation index system for different types of oil reservoirs in complex fault blocks, as shown in an embodiment of the invention. Figure 2 As shown, the evaluation indicators include: 5 geological characteristic indicators, 4 development characteristic indicators, and 1 economic benefit indicator. The weights of each evaluation indicator are determined based on their impact on the sidetracking potential of different types of reservoirs in complex fault blocks.

[0067] Furthermore, in step S1, the evaluation indicators that affect the sidetracking potential of different types of reservoirs include:

[0068] The evaluation indicators in the heavy oil reservoir sidetracking potential index system include: structural location coefficient, oil layer thickness, remaining recoverable reserves, comprehensive water cut, well pattern and spacing coefficient, carbon dioxide huff and puff cycles, and sidetracking cost, with a weight of W = (0.15, 0.1, 0.25, 0.1, 0.15, 0.1, 0.15).

[0069] The evaluation indicators in the sidetracking potential index system for light oil reservoirs include: structural location coefficient, oil layer thickness, remaining recoverable reserves, comprehensive water cut, well pattern and well spacing coefficient, pressure coefficient, and sidetracking cost, with a weight of W = (0.2, 0.1, 0.2, 0.1, 0.1, 0.1, 0.1, 0.1).

[0070] The structural location coefficient refers to the ratio of the oil column height at a given elevation to the oil column height in the reservoir, based on the relationship between elevation and location. It is used to reflect the influence of reservoir structural location on reservoir sidetracking potential. Structural location coefficient = (target elevation - lowest elevation of reservoir) / (highest elevation of reservoir - lowest elevation of reservoir).

[0071] The well spacing coefficient is the ratio of the absolute value of the difference between the straight-line distance between the target well and the adjacent well and the optimal design well spacing to the optimal design well spacing. It is used to reflect the well network deployment in order to characterize the reservoir development process. Well spacing coefficient = |(straight-line distance between the target well and the adjacent well - optimal design well spacing)| / optimal design well spacing;

[0072] In practice, evaluation indicators that affect the sidetracking potential of different types of reservoirs in complex fault blocks are selected. Through methods such as field data analysis, numerical simulation, and expert opinions, an evaluation index system for the sidetracking potential of different types of reservoirs in complex fault blocks is established, consisting of multiple evaluation indicators.

[0073] Oil layer thickness refers to the average thickness of oil layers encountered by adjacent wells; the remaining recoverable reserves are calculated as geological reserves × rated recovery rate - cumulative oil production; the comprehensive water cut is calculated as the ratio of daily water production to daily fluid production; the pressure coefficient is calculated as the ratio of formation pressure in the target area to the original formation pressure; the sidetracking cost is calculated as drilling cost + surface cost.

[0074] Step S2: Determine the distribution of evaluation levels and the corresponding evaluation classification standards for each evaluation indicator in each evaluation level;

[0075] Specifically, the evaluation indicators are classified into four levels: "Category I, Category II, Category III, and Category IV," and an evaluation index system for the sidetracking potential of different types of oil reservoirs in complex fault blocks is established.

[0076] In practical implementation, to obtain universally accepted threshold ranges for various evaluation indicators, the threshold ranges are determined based on the oil and gas industry standard "Classification of Oilfield Development Levels" (SY / T 6219-1996), combined with research on the specific circumstances of the variation patterns of indicators in complex fault-block reservoirs. For evaluation indicators specified in the industry standard, the threshold ranges follow the original industry standard; for evaluation indicators without industry standards, their threshold ranges are determined through methods such as field data analysis, numerical simulation, and expert opinions. In this implementation step, the thresholds of each evaluation indicator are the limits of the evaluation indicator values ​​characterizing the degree of potential for sidetracking.

[0077] Step S3: Establish an unknown measure function for a single index and statistically analyze the actual values ​​of each evaluation index of the target reservoir; determine the quantitative value of a single index; further, step S3 also includes: establishing a membership function and determining the quantitative value of a single index.

[0078] In practice, the membership function is established, and the quantitative value of a single indicator is determined by: establishing a single-factor unknown measure function one by one, and calculating the scores of each evaluation indicator. Figure 3 This invention illustrates a single-index measurement function for the unknown measure of heavy oil reservoirs in a sidetracking potential evaluation method for different types of complex fault-block reservoirs, as shown in an embodiment of the present invention. Figure 4 This invention illustrates a single-index measurement function for the unknown measure of light oil reservoirs in a sidetracking potential evaluation method for different types of complex fault-block reservoirs, as shown in an embodiment of the present invention.

[0079] It should be noted that the uncertain measure method is a comprehensive evaluation method based on the uncertain measure theory.

[0080] Given x1, x2, x3, ..., x n There are n sample points, let x1, x2, x3, ..., xn. n The object space has unknown measures. Evaluation parameters x1, x2, x3, ..., x n The index space for establishing the evaluation parameter system is denoted as I = {I1, I2, I3, ..., I...} n Let x ij x represents i About I j The monitoring value for x ij There are k evaluation levels, denoted by U, which is its evaluation space. Then U = {C1, C2, C3, ..., C} k If C1 is "better" than C2, it is denoted as C1 > C2 > C3 > C k Let {C1, C2, C3, C4} be an ordered partition class of the evaluation space U.

[0081] Let the monitored value be x ij Belongs to C k The degree is expressed by u ijk=u(x ij ∈C k This means that u satisfies:

[0082] 0≤u(x ij ∈C k )≤1 (1)

[0083] u(x ij ∈U)=1 (2)

[0084]

[0085] In equations (1) to (3): i = 1, 2, ..., n; j = 1, 2, ..., m; k = 1, 2, ..., p.

[0086] Equations (1) and (2) respectively indicate that the evaluation space U satisfies normality and additivity. The u that satisfies equations (1), (2) and (3) is called an unknown measure.

[0087] The interpretation of a single-index unknowable measure is as follows: The matrix U is called... imp Yes((u ijk ) m×p For x i The single-index measurement evaluation matrix is ​​shown in equation (4).

[0088]

[0089] Step S4: Based on a comprehensive evaluation of multiple indicators, classify the potential level of side-drilling;

[0090] Further, step S4: Based on a comprehensive evaluation of multiple indicators, the potential levels for side-drilling are classified, including:

[0091] Establish a multi-indicator comprehensive evaluation. Based on the single-factor measurement matrix and indicator weights, calculate the multi-indicator comprehensive measure, using u... ik =u(x i ∈c k ) represents sample x i Belongs to c k The degree of the evaluation level is as follows:

[0092]

[0093] In the formula: u ijk To represent sample x i The single-factor measurement values ​​of the j-th evaluation index;

[0094] i is the i-th sample among 1 to n samples;

[0095] j is the j-th indicator among 1 to m indicators;

[0096] K is the kth evaluation level among 1-p evaluation levels;

[0097] i=1,2,…,n;j=1,2,…,m;k=1,2,…,p;

[0098] wj is the weight of the j-th indicator.

[0099] u determined by equation (5) ik It is an uncertain measure, and equation (6) is a multi-index comprehensive measure evaluation matrix; sample x i The multi-index comprehensive measurement evaluation vector is the i-th row vector (u) in equation (6). i1 u ik , ..., u ip );

[0100]

[0101] The membership degree of each sample at each evaluation level is calculated sequentially; the comprehensive evaluation matrix is ​​obtained by multiplying the weight coefficient with the multi-index comprehensive measurement matrix; the comprehensive evaluation level of each sample is determined according to the confidence principle; finally, the final scores are sorted by assigning values ​​according to the empirical formula.

[0102] Since C1 > C2 > ... > C p We introduce a confidence level identification criterion, where λ is the confidence level (λ≥0.6). If... It is possible to determine x i Belongs to C k Based on the confidence level principle, we set λ = 0.6 and k0 = u. i1 +u i2 =0.61, at this time k0 is greater than 0.6, belonging to C2.

[0103] Step S5: Calculate the comprehensive score based on the multi-indicator comprehensive evaluation vector and evaluation space assignment. Comprehensive score Q Ai It is the product of a multi-indicator comprehensive measurement evaluation vector and the values ​​assigned to different evaluation levels;

[0104] Based on the preset scoring levels, the level of the summation value is determined, and this level is used as the quantitative evaluation result of the sidetracking potential of different types of complex fault blocks in the reservoir to be evaluated. The different evaluation levels are assigned values ​​of C1=4, C2=3, C3=2, and C4=1.

[0105] The multi-index comprehensive measurement and evaluation vector is sample x. i The multi-index comprehensive measurement evaluation vector is the i-th row vector (u) in equation (6). i1 u ik , ..., u ip );

[0106] Q Ai=μ i1 ×4+μ i2 ×3+μ i3 ×2+……+μ ip ×1

[0107] Evaluate multiple target regions A1, A2, ..., A i , ..., A n The target area is determined by assigning a score of Q to each target area. A1 Q A2 ...Q An By sorting the scores, the potential order of different target areas in the same oilfield can be obtained.

[0108] This invention provides a method for evaluating the sidetracking potential of complex fault-block reservoirs of different types. It introduces two evaluation indicators—structural location coefficient and well spacing coefficient—to establish an evaluation system for the sidetracking potential of different reservoir types. A single-index evaluation function is established using an uncertain measure function, and the weights of each evaluation parameter for different reservoirs are analyzed. An uncertain measure method is then used to comprehensively evaluate the sidetracking potential. This method covers three major categories and seven potential evaluation indicators, providing a more accurate assessment of reservoir sidetracking potential, improving the production rate of sidetracked wells, and offering simple operation, strong adaptability, and the ability to reflect the sidetracking potential of different reservoir types. The evaluation results can provide a basis for targeted sidetracking and production construction, demonstrating significant practical engineering application value.

[0109] Furthermore, the quantitative evaluation method for sidetracking potential of different types of reservoirs in complex fault blocks provided by this invention achieves multi-factor quantitative evaluation of the sidetracking potential of different types of reservoirs in complex fault blocks. The evaluation parameters are simple to obtain, the evaluation process is simple and easy to operate, and it has strong field applicability. The unique quantitative evaluation results of the target reservoir can scientifically and accurately evaluate the sidetracking potential of different types of reservoirs in complex fault blocks, identify the main factors restricting the sidetracking potential of the reservoir, and provide a basis for targeted development adjustments in the next step. Using this method to evaluate the sidetracking potential of eight research target areas in the Jidong Oilfield, the evaluation results achieved a compliance rate of over 95%. It can be applied to the quantitative evaluation of sidetracking potential of different types of reservoirs. The evaluation parameters are simple to obtain, the evaluation process is simple and easy to operate, which is conducive to large-scale field promotion and application. It can provide guidance for the quantitative evaluation of sidetracking potential of similar reservoirs in China, such as Jidong, Shengli, Dagang, and Liaohe, and has broad application prospects.

[0110] Example 1: Evaluation of Sidetracking Potential in Heavy Oil Reservoirs

[0111] The research object of this embodiment is the A1 target area unit of reservoir A, which belongs to heavy oil reservoir. The method for evaluating the sidetracking potential of complex fault-block reservoirs of different types according to the present invention includes the following steps:

[0112] Step S1: Differentiate reservoir types based on the different oil properties of complex fault-block reservoirs.

[0113] In practice, reservoirs are classified according to their fluid properties into two categories: light oil reservoirs and heavy oil reservoirs. Light oil reservoirs are those with crude oil viscosity less than 50 mPa·s and crude oil relative density less than 0.92. Heavy oil reservoirs are those with crude oil viscosity greater than 50 mPa·s and crude oil relative density greater than 0.92 under reservoir conditions. Reservoir A, with crude oil viscosity of 150 mPa·s and relative density of 0.96, belongs to the heavy oil reservoir category.

[0114] Step S2: Select evaluation indicators affecting the sidetracking potential of heavy oil reservoirs and establish a sidetracking potential indicator system, including two geological characteristic indicators (structural location coefficient and reservoir thickness), four development characteristic indicators (remaining recoverable reserves, comprehensive water cut, well pattern and well spacing coefficient, and CO2 huff and puff cycles), and one economic benefit indicator (sidetracking cost). Based on the degree of influence of each evaluation indicator on the sidetracking potential, obtain the weight coefficient of each element, and then calculate the weight of each evaluation indicator, as shown in Table 1.

[0115] Table 1A1 Weights of Evaluation Indicators for the Target Area

[0116]

[0117]

[0118] Based on the reservoir development characteristics of the A1 target area unit, the evaluation indicators were determined according to four evaluation standards: "Class I, Class II, Class III, and Class IV", as shown in Table 2.

[0119] Table 2A1 Target Area Evaluation Classification Standards

[0120]

[0121] Step S3: Based on the unknown measurement function, the degree of belonging to different levels is determined by the single-factor grading calculation method, and the seven indicators are evaluated in turn to obtain the multi-indicator evaluation matrix of side-drilling potential.

[0122] Based on the production data of the A1 target area unit, the actual values ​​of each evaluation index for the A1 target area unit were determined, as shown in Table 3. The highest elevation of reservoir A is -1820 meters, and the lowest is -1860 meters; the elevation of reservoir A1 target area is -1830 meters; the oil layer thickness is 9 meters; the remaining recoverable reserves are 0.8 million tons; the overall water cut is 85%; the distance to adjacent wells is 110 meters, and the optimal well spacing is 100 meters; there are 3 rounds of CO2 injection; the sidetracking drilling cost is 2.4 million, and the surface cost is 200,000. The actual values ​​of the sidetracking potential evaluation index parameters for the A1 target area are shown in Table 3.

[0123] Table 3A1 Actual Values ​​of Target Area Side Drilling Potential Evaluation Indicators

[0124]

[0125] in

[0126] The structural position coefficient = (-1830-1860) / (-1820-1860) = 0.75;

[0127] Well spacing coefficient = |110-100| / 100 = 0.1;

[0128] Sidetracking drilling cost = 240 + 20 = 260 million.

[0129] The multi-index evaluation matrix of the drilling potential in the A1 target area is as follows:

[0130]

[0131] Step S4: Based on the weights and multi-index evaluation matrix, a comprehensive evaluation result is obtained, resulting in a comprehensive evaluation matrix (0.61, 0.29, 0.025, 0.075). A confidence level > 0.6 is used to classify the scoring levels. The evaluation result for the drilling potential of target area A1 is determined to be "Class I," indicating that the drilling potential of target area A1 is relatively good.

[0132] Step S5: Calculate the overall score, resulting in a total evaluation score of 0.8588 for target area A1. The evaluation result is consistent with the actual production situation in target area A1, indicating that this evaluation method can meet the requirements for evaluating side-drilling potential.

[0133] Q A1 =0.61×4+0.29×0.29×3+0.025×2+0.075×1=0.8588

[0134] Evaluate multiple target regions A1, A2, ..., A n The target area is determined by assigning a score of Q to each target area. A1 Q A2 ...Q An By sorting the scores, the potential order of different target areas in the same oilfield can be obtained.

[0135] Example 2 Evaluation of Sidetracking Potential in Light Oil Reservoirs

[0136] The research object of this embodiment is the B1 target area unit of reservoir B, which belongs to heavy oil reservoir. The method for evaluating the sidetracking potential of complex fault-block reservoirs of different types according to the present invention includes the following steps:

[0137] Step S1: Differentiate reservoir types based on the different oil properties of complex fault-block reservoirs.

[0138] In practice, reservoirs are classified according to their fluid properties into two categories: light oil reservoirs and heavy oil reservoirs. Light oil reservoirs are those with crude oil viscosity less than 50 mPa·s and relative density less than 0.92. Heavy oil reservoirs are those with crude oil viscosity greater than 50 mPa·s and relative density greater than 0.92 under reservoir conditions. Reservoir B, with crude oil viscosity of 25 mPa·s and relative density of 0.8, belongs to the light oil reservoir category.

[0139] Step S2: Select evaluation indicators that affect the sidetracking potential of light oil reservoirs and establish a sidetracking potential indicator system, including 2 geological characteristic indicators (structural location coefficient, oil layer thickness), 4 development characteristic indicators (remaining recoverable reserves, comprehensive water cut, well pattern and well spacing coefficient, pressure coefficient), and 1 economic benefit indicator (sidetracking cost).

[0140] Based on the degree of influence of each evaluation index on the side drilling potential, the weight coefficient of each element was obtained, and then the weight of each evaluation index was calculated, as shown in Table 4.

[0141] Table 4B1 Weights of Evaluation Indicators for the Target Area

[0142]

[0143] Based on the reservoir development characteristics of the B1 target area unit, the evaluation indicators were determined to be classified into four evaluation levels: "Class I, Class II, Class III, and Class IV", as shown in Table 5.

[0144] Table 5B1 Target Area Evaluation Classification Standards

[0145]

[0146] Step S3: Based on the unknown measurement function, the degree of belonging to different levels is determined by the single-factor grading calculation method, and the seven indicators are evaluated in turn to obtain the multi-indicator evaluation matrix of side-drilling potential.

[0147] Based on the production data of target area unit B, the actual values ​​of each evaluation index of target area unit B1 were determined, as shown in Table 6. The highest elevation of reservoir B is -1700 meters, and the lowest is -1760 meters; the elevation of reservoir B1 is -1740 meters; the oil layer thickness is 5 meters; the remaining recoverable reserves are 0.8 million tons; the overall water cut is 85%; the distance to adjacent wells is 200 meters, and the optimal well spacing is 150 meters; the pressure coefficient is 0.7; the sidetracking drilling cost is 2.8 million, and the surface cost is 200,000. The actual values ​​of the sidetracking potential evaluation index parameters for target area B1 are shown in Table 6.

[0148] Table 6B1 Actual Values ​​of Target Area Side-Drilling Potential Evaluation Indicators

[0149] Construction position coefficients oil layer thickness Remaining recoverable reserves Overall water content Well spacing coefficient pressure coefficient Side-drilling cost -1720 5 1.2 60 0.33 0.67 300

[0150] in,

[0151] The structural position coefficient = (-1720-1760) / (-1700-1760) = 0.67;

[0152] Well spacing coefficient = |200-150| / 150 = 0.33;

[0153] Sidetracking drilling cost = 280 + 20 = 3 million tons.

[0154] The multi-index evaluation matrix of the side drilling potential in the B1 target area is as follows:

[0155]

[0156] Step S4: Based on the weights and multi-index evaluation matrix, a comprehensive evaluation result is obtained, resulting in a comprehensive evaluation matrix (0.28, 0.37, 0.25, 0.1). A confidence level > 0.6 is used to classify the scoring levels. Classifying the scoring levels determines that the drilling potential of the B1 target area is classified as Class II, indicating that the drilling potential of the B1 target area is relatively good.

[0157] Step S5: Calculate the overall evaluation score, which gives the total evaluation score Q for target area B1. B1 =0.7075 points; Q B1 = (0.28×4+0.37×3+0.25×2+0.1×1) / 4 = 0.7075.

[0158] Evaluate multiple target regions B1, B2, ..., B n The target area is determined by assigning a score of Q to each target area. B1 Q B2 ...Q Bn The results are then sorted to obtain the potential ranking of different target areas within the same oilfield. The evaluation results are consistent with the drilling encounters in the sidetracking wells of target area B1, indicating that this evaluation method can meet the requirements for sidetracking potential evaluation.

[0159] The second aspect of this invention discloses a system for evaluating the sidetracking potential of complex fault-block reservoirs of different types, which can be used to execute all the methods in the method for evaluating the sidetracking potential of complex fault-block reservoirs of different types in the first aspect of this invention. The system includes:

[0160] The first processing module is configured to determine the reservoir type, select evaluation indicators that affect the sidetracking potential of different types of reservoirs, and establish the weights of each evaluation indicator.

[0161] The second processing module is configured to determine the distribution of evaluation levels and the evaluation classification criteria corresponding to each evaluation indicator in each evaluation level.

[0162] The third processing module is configured to: establish a single-index unknown measurement function; statistically analyze the actual values ​​of each evaluation index of the target reservoir; and determine the quantitative value of a single index.

[0163] The fourth processing module is configured to classify the potential level of side-drilling based on a comprehensive evaluation of multiple indicators.

[0164] The fifth processing module is configured to calculate the comprehensive score based on the multi-indicator comprehensive evaluation vector and the evaluation space assignment.

[0165] In summary, the method provided by this invention has the following beneficial effects:

[0166] 1. This invention proposes the concept of evaluating sidetracking potential based on reservoir type, which accurately characterizes the size of the sidetracking potential in the target area and makes up for the problem that the potential evaluation is not accurate enough when the same parameter is used for reservoirs with different conditions.

[0167] 2. For the first time, a sidetracking potential evaluation index system for different types of reservoirs was established, covering three major categories and seven potential evaluation indicators. This system can reflect sidetracking potential, making the evaluation results more comprehensive, integrated, targeted, adaptable, and accurate.

[0168] 3. This application proposes two concepts: structural location coefficient and well pattern spacing coefficient. It quantifies the structural location index, introduces the well pattern spacing coefficient, normalizes different well spacing positions, optimizes the sidetracking potential evaluation index system, and improves the accuracy of sidetracking potential evaluation.

[0169] 4. This application establishes a single-index unknown measure function, realizes the hierarchical and quantitative evaluation of geological parameters in the target area, the evaluation parameters are easy to obtain, the evaluation process is simple and easy to operate, it has strong field applicability, and the evaluation results can provide a basis for the next step of sidetracking deployment.

[0170] This invention provides a unified technical methodology system for evaluating the sidetracking potential of different types of reservoirs in complex fault blocks—an evaluation index system for the sidetracking potential of different types of reservoirs in complex fault blocks. This system enables multi-factor quantitative evaluation of the sidetracking potential of different types of reservoirs in complex fault blocks and provides targeted guidance for sidetracking potential tapping schemes based on the evaluation results.

[0171] A third aspect of this invention discloses an electronic device. The electronic device includes a memory and a processor. The memory stores a computer program, and when the processor executes the computer program, it implements the steps in the sidetracking potential evaluation method for complex fault-block reservoirs of different types, as disclosed in any of the first aspects of this invention.

[0172] The electronic device includes a processor, memory, communication interface, display screen, and input device connected via a system bus. The processor provides computing and control capabilities. The memory includes non-volatile storage media and internal memory. The non-volatile storage media stores the operating system and computer programs. The internal memory provides the environment for the operation of the operating system and computer programs stored in the non-volatile storage media. The communication interface is used for wired or wireless communication with external terminals; wireless communication can be achieved through Wi-Fi, carrier networks, Near Field Communication (NFC), or other technologies. The display screen can be an LCD screen or an e-ink screen. The input device can be a touch layer covering the display screen, buttons, a trackball, or a touchpad mounted on the device's casing, or an external keyboard, touchpad, or mouse.

[0173] A fourth aspect of this invention discloses a computer-readable storage medium. The computer-readable storage medium stores a computer program, which, when executed by a processor, implements the steps of a sidetracking potential evaluation method for complex fault-block reservoirs of different types, as disclosed in any of the first aspects of this invention.

[0174] Please note that the technical features of the above embodiments can be combined arbitrarily. For the sake of brevity, not all possible combinations of the technical features in the above embodiments have been described. However, as long as the combination of these technical features does not contradict each other, it should be considered within the scope of this specification. The above embodiments only illustrate several implementation methods of this application, and their descriptions are relatively specific and detailed, but they should not be construed as limiting the scope of the invention patent. It should be pointed out that for those skilled in the art, several modifications and improvements can be made without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this patent application should be determined by the appended claims.

[0175] The above are preferred embodiments of the present invention. It should be noted that, for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A method for evaluating the sidetracking potential of complex fault-block reservoirs of different types, characterized in that, include: Step S1: Determine the reservoir type, select evaluation indicators that affect the sidetracking potential of different reservoir types, and establish the weights of each evaluation indicator; Step S2: Determine the distribution of evaluation levels and the evaluation classification criteria corresponding to each evaluation indicator in each evaluation level; Step S3: Establish a single-index unknown measurement function, statistically analyze the actual values ​​of each evaluation index of the target reservoir; determine the quantitative value of each index; Step S4: Based on a comprehensive evaluation of multiple indicators, classify the potential level of side-drilling; Step S5: Calculate the comprehensive score based on the multi-index comprehensive evaluation vector and the evaluation space assignment.

2. The method for evaluating the sidetracking potential of complex fault-block reservoirs of different types according to claim 1, characterized in that, In step S1, the selection of evaluation indicators affecting the sidetracking potential of different types of reservoirs includes: The evaluation indicators in the heavy oil reservoir sidetracking potential index system include: structural location coefficient, oil layer thickness, remaining recoverable reserves, comprehensive water cut, well pattern and spacing coefficient, carbon dioxide huff and puff cycles, and sidetracking cost, with a weight of W = (0.15, 0.1, 0.25, 0.1, 0.15, 0.1, 0.15). The evaluation indicators in the sidetracking potential index system for light oil reservoirs include: structural location coefficient, oil layer thickness, remaining recoverable reserves, comprehensive water cut, well pattern and well spacing coefficient, pressure coefficient, and sidetracking cost, with a weight of W = (0.2, 0.1, 0.2, 0.1, 0.1, 0.1, 0.1, 0.1).

3. The method for evaluating the sidetracking potential of complex fault-block reservoirs of different types according to claim 2, characterized in that: The structural location coefficient refers to the ratio of the oil column height corresponding to the current elevation to the oil column height of the reservoir, based on the elevation relationship; Structural location coefficient = (target elevation - lowest elevation of the reservoir) / (highest elevation of the reservoir - lowest elevation of the reservoir). And / or, the oil layer thickness refers to the average thickness of oil layers encountered in adjacent wells; And / or, the remaining recoverable reserves are calculated as geological reserves × rated recovery rate - cumulative oil production; And / or, the comprehensive water content calculation method is the ratio of daily water production to daily liquid production; And / or, the well network spacing coefficient is the ratio of the absolute value of the difference between the straight distance between the target well and the adjacent well and the design optimal well spacing to the design optimal well spacing; well network spacing coefficient = |(straight distance between the target well and the adjacent well - design optimal well spacing)| / design optimal well spacing; And / or, the pressure coefficient is calculated as the ratio of the formation pressure in the target area to the original formation pressure; And / or, the sidetracking cost calculation method is drilling cost + surface cost.

4. The method for evaluating the sidetracking potential of complex fault-block reservoirs of different types according to any one of claims 1 to 3, characterized in that, Step S3 further includes: Establish a membership function to determine the quantified value of a single indicator.

5. The method for evaluating the sidetracking potential of complex fault-block reservoirs of different types according to claim 4, characterized in that, The establishment of the membership function to determine the quantified value of a single indicator includes: Establish one-factor unknown measure functions for each factor, and calculate and score each evaluation index.

6. The method for evaluating the sidetracking potential of complex fault-block reservoirs of different types according to any one of claims 1 to 3, characterized in that, Step S4: Based on a comprehensive evaluation of multiple indicators, the potential levels for side-drilling are classified, including: A multi-index comprehensive evaluation is established, and a multi-index comprehensive measure is obtained according to a single factor measure matrix and index weight, wherein u ik = u(x i ∈ c k ) represents a degree to which a sample x i belongs to an evaluation grade c k , and then: wherein: u ij k is a sample x i is the single-factor measure value of the jth evaluation index i is the i-th sample among 1 to n samples; j is the j-th indicator among 1 to m indicators; K is the kth evaluation level among 1-p evaluation levels; i=1,2,…,n;j=1,2,…,m;k=1,2,…,p; wj is the weight of the j-th indicator; u is determined by formula (5) ik is the unascertained measure, and formula (6) is a multi-index comprehensive measure evaluation matrix; a multi-index comprehensive measure evaluation vector of the sample x i is the i-th row vector (u i1 , u ik ,..., u ip ) in formula (6); The membership degree of each sample at each evaluation level is calculated sequentially; the comprehensive evaluation matrix is ​​obtained by multiplying the weight coefficient with the multi-index comprehensive measurement matrix; the comprehensive evaluation level of each sample is determined according to the confidence principle; finally, the final scores are sorted by assigning values ​​according to the empirical formula.

7. The method for evaluating the sidetracking potential of complex fault-block reservoirs of different types according to claim 1 or 2, characterized in that, In step S5: Overall Score Q Ai It is the product of a multi-indicator comprehensive measurement evaluation vector and the values ​​assigned to different evaluation levels; The different evaluation levels are assigned the values ​​C1=4, C2=3, C3=2, and C4=1. The multi-index comprehensive measurement and evaluation vector is sample x. i The multi-index comprehensive measurement evaluation vector is the i-th row vector (u) in equation (6). i1 u ik , ..., u ip ); Q Ai =μ i1 ×4+μ i2 ×3+μ i3 ×2+……+μ ip ×1 Evaluate multiple target regions A1, A2, ..., A i , ..., A n The target area is determined by assigning a score of Q to each target area. A1 Q A2 ...Q An By sorting the scores, the potential order of different target areas in the same oilfield can be obtained.

8. A system for evaluating the sidetracking potential of complex fault-block reservoirs of different types, characterized in that, The system includes: The first processing module is configured to determine the reservoir type, select evaluation indicators that affect the sidetracking potential of different types of reservoirs, and establish the weights of each evaluation indicator. The second processing module is configured to determine the distribution of evaluation levels and the evaluation classification criteria corresponding to each evaluation indicator in each evaluation level. The third processing module is configured to: establish a single-index unknown measurement function; statistically analyze the actual values ​​of each evaluation index of the target reservoir; and determine the quantitative value of a single index. The fourth processing module is configured to classify the potential level of side-drilling based on a comprehensive evaluation of multiple indicators. The fifth processing module is configured to calculate the comprehensive score based on the multi-indicator comprehensive evaluation vector and the evaluation space assignment.

9. An electronic device, characterized in that, The electronic device includes a memory and a processor. The memory stores a computer program, and when the processor executes the computer program, it implements the steps in the method for evaluating the sidetracking potential of different types of oil reservoirs in complex fault blocks according to any one of claims 1 to 7.

10. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores a computer program, which, when executed by a processor, implements the steps in the method for evaluating the sidetracking potential of different types of reservoirs in complex fault blocks according to any one of claims 1 to 7.

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