Horizontal well crack parameter optimization method for block integral transformation

Abstract

The invention belongs to the field of petroleum and natural gas, and discloses a horizontal well crack parameter optimization method for block integral transformation, which comprises the following steps: collecting production data; recording production data; setting reservoir parameters: establishing an oil reservoir model by adopting Eclipse or Petrol according to reservoir attributes, selecting a corresponding data module, and setting reservoir attribute parameters; performing history fitting; determining a new well position; different fracture parameter combinations are determined; key factors and simulation parameter combinations are determined; and determining an optimal fracture parameter combination. As a method for determining numerical simulation of oil reservoir fracturing parameters, the accuracy and economy of simulation are greatly improved. The method is mainly used for determining the fracture combination of the whole block, simulating the single well productivity and evaluating new well and old well transformation, and has the characteristics of few required parameters, simplicity and convenience. The method is wide in application range, is suitable for various oil reservoirs and various production conditions, has important guiding significance for determining oil field fracturing parameters, and has huge economic benefits.

Description

Technical Field

[0001] The invention relates to the field of petroleum and natural gas, and in particular to a method for optimizing fracture parameters of a horizontal well for overall transformation of a block. Background Art

[0002] Regarding the optimization method of horizontal well fracture parameters for overall block reconstruction, previous research methods have been to make the fracture length as long and the fracture width as wide as possible, but this method has disadvantages and is prone to waste of resources. Due to different reservoir characteristics and reservoir properties, previous methods cannot achieve optimal economic efficiency.

[0003] The orthogonal test method is also called the orthogonal test design method. It is a mathematical statistics method that uses an "orthogonal table" to arrange and analyze multi-factor experiments. The advantages of this method are that the number of tests is small, the effect is good, the method is simple, it is easy to use, and the efficiency is high. In the study of more complex problems, there are often multiple factors involved. We call the conditions that affect the test indicators that we are going to examine factors, such as the components in the formula. The different states of the various factors to be examined in the experiment are called levels, such as the different contents (or proportions) of a component in the formula test. In order to seek the most optimized production conditions, it is necessary to test various factors and different levels of various factors. This is a problem of multi-factor optimization.

[0004] Through research, the applicant believes that the appropriate crack parameters can be determined by using the orthogonal test evaluation method. Summary of the invention

[0005] In order to make up for the shortcomings of the prior art, the purpose of the present invention is to use the orthogonal test method to determine the fracturing parameters of each horizontal well in the study block. The present invention mainly relies on numerical simulation software and uses the orthogonal test method to determine different fracture parameter combinations, and determines the optimal fracture parameter combination by simulating the overall production of the block with different combinations.

[0006] In order to achieve the above object, the present invention provides a method for optimizing fracture parameters of horizontal wells for overall block transformation, comprising the following steps:

[0007] (1) Collect production data

[0008] Obtain data on old wells in the initial production, oil-generating and pressure-recovery stages, including production flow, cumulative production or produced reserves, production time, shut-in time, bottom hole pressure and open flow;

[0009] (2) Input production data

[0010] Select the corresponding file as data input, assign and specify data columns, adjust, default and set data, and accept data input;

[0011] (3) Reservoir parameter setting

[0012] According to the reservoir properties, Eclipse or Petrol is used to establish the reservoir model, select the corresponding data module, and set the reservoir attribute parameters: model boundary, porosity, permeability, oil saturation, natural fracture direction, and natural fracture length.

[0013] (4) History Matching

[0014] The numerical model was calibrated using actual production data and the fitting was accurate, so the model was considered complete;

[0015] (5) Determine the location of the new well

[0016] Using actual well location data, key parameters such as horizontal well location, well depth, and horizontal section length are established in the model to be as consistent as possible with the actual situation;

[0017] (6) Determine different combinations of crack parameters

[0018] ①Identify key factors

[0019] Determine the factors to be considered, such as the number of wells, fracture length range, fracture width, and conductivity. This time, we take 3 factors and 4 levels as an example. The design table is as follows: Figure 1 As shown;

[0020] ②Determine the simulation parameter combination

[0021] Taking 3 factors and 4 levels as an example, through the orthogonal test method, the design combination is as follows Figure 2 As shown;

[0022] (7) Determine the optimal crack parameter combination

[0023] By simulating the horizontal well production under different parameter combinations, the optimal fracture parameter combination is determined.

[0024] Compared with the prior art, the present invention has the following beneficial effects:

[0025] A method for optimizing the fracture parameters of horizontal wells for overall transformation of a block, as a method for numerical simulation of reservoir fracturing parameters, greatly increases the accuracy and economy of the simulation. This method is mainly used to determine the overall fracturing fracture combination of the block, simulate the production capacity of a single well, and evaluate the transformation of new wells and old wells. The invention requires few parameters and is simple and convenient. The method has a wide range of applications and is suitable for various types of reservoirs and a variety of production conditions. It has important guiding significance for determining oil field fracturing parameters and has huge economic benefits. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 This is an example of a 3-factor 4-level table;

[0027] Figure 2 It is a 3-factor 4-level orthogonal design combination;

[0028] Figure 3 It is a bar graph of crack parameters in Example 1. DETAILED DESCRIPTION

[0029] In order to make the technical means and objectives of the present invention easy to understand, the present invention is further described below in conjunction with specific embodiments. The experimental methods used in the following examples are all conventional methods unless otherwise specified.

[0030] Example 1

[0031] (1) Collect production data

[0032] Obtain data on old wells in the initial production stage, oil generation stage, and pressure recovery stage, including production flow, cumulative production (or produced reserves), production date and time, and other parameters.

[0033] (2) Input production data

[0034] Select the corresponding file as data input, allocate and specify data columns, adjust, default and set data, and accept data input.

[0035] (3) Reservoir parameter setting

[0036] According to the reservoir attributes, select the corresponding data module, set the reservoir attribute parameters, and update and use the user-defined parameters.

[0037] (4) History Matching

[0038] The numerical model was calibrated using actual production data and the fitting was accurate, so the model was considered to be complete.

[0039] (5) Determine the location of the new well

[0040] Using actual well location data, key parameters such as horizontal well location, well depth, and horizontal section length are established in the model to be as consistent as possible with the actual situation.

[0041] (6) Determine different combinations of crack parameters

[0042] ①Identify key factors

[0043] This simulation assumes that the crack height is 77 meters, and designs an orthogonal experiment (12 factors and 3 levels) with crack length 1, dimensionless conductivity 1, crack length 2, dimensionless conductivity 2, ..., crack length 6, dimensionless conductivity 6.

[0044] The calculation formula of dimensionless conductivity is as follows:

[0045] Fcd =(K f w) / (Kx f ) (1)

[0046] Where K f - fracture permeability;

[0047] w - support crack width;

[0048] K-reservoir permeability;

[0049] x f -Support the crack half length.

[0050] The designed crack lengths are 180m, 220m, and 260m, and the dimensionless conductivity is 0.1, 1, and 10.

[0051] The design table is as follows:

[0052]

[0053] ②Determine the simulation parameter combination

[0054] 12 factors and 3 levels, through orthogonal test method, the design combination is as follows:

[0055]

[0056]

[0057] (7) Determine the optimal crack parameter combination

[0058] By simulating the horizontal well production under different parameter combinations, the optimal fracture parameter combination is determined.

[0059]

[0060]

[0061] Although some embodiments of the present invention have been given herein, those skilled in the art should understand that the embodiments of the present invention may be modified without departing from the spirit of the present invention. The above embodiments are merely exemplary and should not be used as a limitation on the scope of the present invention.

Claims

1. A method for optimizing fracture parameters of horizontal wells for overall block transformation, characterized in that: The steps include: (1) Collect production data; (2) Input production data; (3) Reservoir parameter setting: Based on reservoir attributes, use Eclipse or Petrol to build a reservoir model, select the corresponding data module, and set reservoir attribute parameters; (4) Historical matching; (5) Determine the location of the new well; (6) Determine different combinations of crack parameters; ①Identify key factors; ②Determine the simulation parameter combination; (7) Determine the optimal combination of crack parameters.

2. A method for optimizing horizontal well fracture parameters for overall block transformation according to claim 1, characterized in that: The production data include production flow, cumulative production or produced reserves, production time, shut-in time, bottom hole pressure, and open flow.

3. The method for optimizing horizontal well fracture parameters for overall block reconstruction according to claim 1, characterized in that: The specific steps of entering production data are: selecting the corresponding file as data input, allocating and specifying data columns, adjusting, defaulting and setting data, and accepting data input.

4. The method for optimizing horizontal well fracture parameters for overall block reconstruction according to claim 1, characterized in that: The reservoir attribute parameters include: model boundary, porosity, permeability, oil saturation, natural fracture direction, and natural fracture length.

5. The method for optimizing horizontal well fracture parameters for overall block reconstruction according to claim 1, characterized in that: The specific steps of the history matching are: using actual production data to calibrate the numerical model, if the fitting is accurate, then the model is established.

6. The method for optimizing horizontal well fracture parameters for overall block reconstruction according to claim 1, characterized in that: The specific steps of determining the location of the new well are: using the actual well location data, establishing key parameters such as the horizontal well location, well depth, and horizontal section length in the model, which are as consistent as possible with the actual situation.

7. The method for optimizing horizontal well fracture parameters for overall block reconstruction according to claim 1, characterized in that: The key factors are: number of wells, fracture length range, fracture width, and dimensionless conductivity.

8. The method for optimizing horizontal well fracture parameters for overall block reconstruction according to claim 1, characterized in that: The method used to determine the simulation parameter combination is the orthogonal test method.

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