An evaluation method and device for oilfield safety management

Abstract

The present application discloses an evaluation method and device for oilfield safety management, which relates to the field of petroleum and natural gas engineering technology. The method includes: dividing the target development block of the oilfield to obtain the production wells of the safety management evaluation unit; obtaining the downhole core basic parameters of the production wells of the safety management evaluation unit; calculating the fracture performance morphological index of the target core according to the downhole core basic parameters; combining the fracture performance morphological index with the downhole core basic parameters to determine the safety management coefficient of the production well of the safety management evaluation unit; dividing the risk level of the production well of the safety management evaluation unit according to the safety management coefficient to quantitatively evaluate its safety risk. In the process of oilfield development, this method quantitatively evaluates the stability of the rock and then evaluates the safety risk of the production well, solves the problem of quantitative evaluation of the safety of the production well casing in the process of oilfield development, thereby achieving the purpose of reasonable management of oilfield safety and promoting high-quality development of oilfields.

Description

Technical Field

[0001] The present application relates to the field of petroleum and natural gas engineering technology, and in particular to an evaluation method and device for oilfield safety management. Background Art

[0002] At present, China's energy development has entered the unconventional era, and the exploration and development of tight oil and gas has also increased. However, compared with the tight oil and gas reservoirs in North America, China's tight reservoirs are tighter, with strong heterogeneity in the vertical and horizontal directions, discontinuous sand bodies, and alternating sand and mud stacking. At the same time, natural fractures and faults are developed. This geological natural influencing factor brings great challenges to the quantitative evaluation of rock strength and stability. In the process of production well fracturing, there is a major safety problem, that is, during the reservoir transformation, the casing is deformed due to uneven force, and the production well cannot complete the normal reservoir and transformation and production increase measures, which eventually leads to the scrapping of the entire well, causing huge economic losses. Oilfield safety management involves all aspects and is the core factor affecting the high-quality economic development of oilfields. Quantitatively evaluating the safety management issues of oilfields, classifying the problems, and then formulating reasonable solutions are the top priorities for solving the efficient development of unconventional tight oil and gas.

[0003] Traditional oilfield safety management evaluation relies on the experience and judgment of experts, which has strong subjective influence factors. In recent years, through the continuous improvement of the management evaluation system, convolutional neural networks have been introduced to encode and classify problems, thereby improving the accuracy of problem classification results. However, the existing technology mainly evaluates environmental issues in oilfield safety or the safety of enterprise operating equipment. These evaluation methods are made from the perspective of system safety management and have limited application scope.

[0004] In addition, although the existing evaluation methods also use the risk assessment matrix method to classify the safety issues of oil fields, the classification rules are simple and insufficient to cope with the different geographical conditions of tight reservoirs. The scope of application is limited and the judgment of the actual geographical conditions is not accurate enough, which ultimately leads to a broad classification of problems, which in turn leads to biased decisions made by managers. It is unable to meet the needs of the current actual development of various oil fields for the safe handling of casing changes, affecting the high-quality development of various oil fields. Summary of the invention

[0005] The embodiment of the present application solves the problem of inaccurate classification of oilfield safety management problems and difficulty in meeting the requirements of casing change processing in the prior art by providing an evaluation method and device for oilfield safety management. The fracture morphological index of the rock is calculated based on the acquired downhole core basic parameters, and the stability of the rock is quantitatively evaluated by taking into full consideration various influencing factors. The safety management coefficient of the production well of the safety management evaluation unit is calculated by combining the macro-micro fracture index of the rock with the downhole core basic parameters, and the risk level is divided, thereby achieving the purpose of oilfield safety management.

[0006] In a first aspect, an embodiment of the present application provides an evaluation method for oilfield safety management, characterized in that it includes: dividing the target development block of the oilfield to obtain production wells of the safety management evaluation unit; obtaining the downhole core basic parameters of the production wells of the safety management evaluation unit; calculating the fracture manifestation morphology index of the target core according to the downhole core basic parameters; determining the safety management coefficient of the production wells of the safety management evaluation unit by combining the fracture manifestation morphology index and the downhole core basic parameters; and dividing the production wells of the safety management evaluation unit into risk levels according to the safety management coefficient to quantitatively evaluate their safety risks.

[0007] In a possible implementation, the obtaining of the basic parameters of the downhole core of the production well of the safety management and evaluation unit includes: obtaining the target core of the production well of the safety management and evaluation unit and its stress-strain curve, and the rock mechanics parameters of the target core; obtaining the mineral percentage, porosity and particle size distribution of the target core.

[0008] In a possible implementation, the fracture morphological index of the rock is calculated according to the downhole core basic parameters, including: the fracture morphological index includes a macro fracture morphological index, a micro weakness direction index and a micro weakness quantity index; wherein the macro fracture morphological index is calculated according to the rock mechanics parameters, the micro weakness direction index is calculated according to the particle size distribution and the porosity, and the micro weakness quantity index is calculated according to the mineral percentage content.

[0009] In a possible implementation, the macroscopic fracture morphology index is calculated according to the rock mechanics parameters as follows:

[0010] ;

[0011] In the formula, It represents the morphological index of the macro crack, dimensionless, represents the peak intensity, represents the yield strength, represents the residual strain, represents the peak strain, represents the residual strength, represents the yield strain.

[0012] In a possible implementation, the microscopic weakness direction index is calculated based on the particle size distribution and the porosity as follows:

[0013] ;

[0014] In the formula, represents the micro-weakness direction index, dimensionless, Indicates the absolute porosity of the target core, represents the effective porosity of the target core, Indicates the percentage of particles with a particle size distribution in the range of 0mm-0.05mm. Indicates the percentage of particles with a particle size distribution in the range of 0.05mm-0.1mm. It indicates the percentage of particles with a particle size distribution greater than 0.1 mm.

[0015] In a possible implementation, the microscopic weakness quantity index is calculated according to the mineral percentage content as follows:

[0016] ;

[0017] In the formula, Represents the number index of micro-weaknesses, dimensionless, Represents the total amount of minerals, Indicates the percentage of different minerals. Indicates different types of minerals. Indicates the value when one mineral is 100% and other minerals are 0%.

[0018] In a possible implementation, before determining the safety management coefficient of the production well of the safety management evaluation unit by combining the fracture morphology index with the downhole core basic parameter, the method further includes:

[0019] According to the confining pressure state of the target core, the microscopic weakness index is corrected to quantitatively evaluate the stability of the rock, as follows:

[0020] ;

[0021] in, ;

[0022] In the formula, express The micro-weakness correction index at , dimensionless, express The micro-weakness correction index at , dimensionless, represents the peak intensity, represents the residual strength, represents the residual strain, represents the peak strain, Indicates no confining pressure correction factor, dimensionless, It represents the peak strength value when there is no confining pressure, dimensionless, It represents the residual strength value when there is no confining pressure, which is dimensionless. represents the residual strain when there is no confining pressure, represents the peak strain when there is no confining pressure.

[0023] In a possible implementation, the safety management coefficient of the production well of the safety management evaluation unit is determined by combining the fracture morphology index with the downhole core basic parameter as follows:

[0024] ;

[0025] In the formula, represents the safety management factor, dimensionless, Represents the morphological index of macro cracks, dimensionless, Represents the micro-weakness direction index, dimensionless, express and The micro-weakness correction index in both cases is dimensionless, Represents the number of micro weaknesses, dimensionless.

[0026] In the second aspect, an embodiment of the present application provides an evaluation device for oilfield safety management, including: a unit division module, used to divide the target development block of the oilfield to obtain production wells of the safety management evaluation unit; a data acquisition module, used to obtain the basic downhole core parameters of the production wells of the safety management evaluation unit; a parameter calculation module, used to calculate the fracture manifestation morphology index of the target core according to the basic downhole core parameters; determine the safety management coefficient of the production well of the safety management evaluation unit by combining the fracture manifestation morphology index and the basic downhole core parameters; an evaluation risk module, used to divide the risk level of the production wells of the safety management evaluation unit according to the safety management coefficient, so as to quantitatively evaluate its safety risk.

[0027] In the third aspect, an embodiment of the present application provides a device for executing an evaluation method for oilfield safety management, the device comprising: a processor; a memory for storing processor executable instructions; when the processor executes the executable instructions, it implements the method described in the first aspect or any possible implementation method of the first aspect.

[0028] One or more technical solutions provided in the embodiments of the present application have at least the following technical effects or advantages:

[0029] The embodiment of the present application adopts an evaluation method and device for oilfield safety management. Based on the basic parameters of the downhole core of the production well of the safety management evaluation unit, the macro crack performance morphology index, micro weakness direction index and micro weakness quantity index of the target core affecting the production well of the safety management evaluation unit are calculated respectively to quantitatively evaluate the stability of the rock, and then the safety management coefficient of the production well of the safety management evaluation unit is calculated in combination with the basic parameters of the downhole core, so as to perform grade classification. It effectively solves the problem of inaccurate classification of oilfield safety management in the prior art and difficulty in meeting the requirements of casing change processing, thereby improving the accuracy and efficiency of oilfield safety management, improving the production increase of production well reservoir transformation, and facilitating the high-quality development of oilfields. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required for use in the embodiments of the present application or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0031] Figure 1 A flowchart of an oilfield safety management evaluation method provided in an embodiment of the present application;

[0032] Figure 2 A comparison chart of the safety management coefficients of production wells in the safety management evaluation unit provided in the embodiment of the present application;

[0033] Figure 3 A schematic diagram of the structure of an oilfield safety management evaluation device provided in an embodiment of the present application. DETAILED DESCRIPTION

[0034] The technical solutions in the embodiments of the present application will be described clearly and completely below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, rather than all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0035] The following describes some of the techniques involved in the embodiments of the present application to facilitate understanding, and they should be considered as merely exemplary. Therefore, it should be appreciated by those of ordinary skill in the art that various changes and modifications may be made to the embodiments described herein without departing from the scope and spirit of the present application. Similarly, for the sake of clarity and conciseness, some descriptions of well-known functions and structures are omitted in the following description.

[0036] Figure 1 It is a flowchart of an oilfield safety management evaluation method provided in an embodiment of the present application, including steps 101 to 105. Figure 1 This is only an execution order shown in the embodiment of the present application, and does not represent the only execution order of the evaluation method for oilfield safety management. In the case that the final result can be achieved, Figure 1 The steps shown may be performed in parallel or in reverse, as follows.

[0037] Step 101: Divide the target development block of the oil field to obtain safety management evaluation unit production wells. In the embodiment of the present application, the target block of oil field development is worked on as a platform, and is divided into multiple safety management evaluation unit production wells. Taking the platform as a unit can integrate a variety of equipment and resources, scientifically plan the layout of the target block and platform, improve management efficiency, and better monitor and respond to various potential risks and hidden dangers, ensuring the smooth development of subsequent oil field development.

[0038] Step 102: Obtain the basic parameters of the downhole core of the production well of the safety management and evaluation unit. In the embodiment of the present application, a special drilling sampling method is used to obtain the standard cylindrical core corresponding to the target reservoir. The appropriate sampling method is selected according to different geological characteristics. The core can be drilled using directional well coring method, horizontal well coring method, closed coring method and pressure-maintaining coring method to meet different geological conditions and exploration needs. Exemplarily, the HH1 platform is selected as the safety management unit. There are 5 production wells of the safety management and evaluation unit, numbered WY1 to WY5. The standard cylindrical target cores corresponding to the target reservoirs of the 5 production wells of the safety management and evaluation unit are obtained respectively. The target core height is about 5 cm and the diameter is about 2.5 cm. The target cores are numbered L1 to L5. By using experimental equipment for studying the mechanical behavior of rocks under complex stress states, such as a triaxial rock mechanics test system, the stress-strain curve of the target core is obtained, and a predetermined confining pressure is applied to the target core sample through a loading system to simulate the lateral stress to which the rock is subjected in nature. The rock mechanical parameters of the target core include peak strength, yield strength, residual strength, peak strain, yield strain and residual strain. The mechanical parameter table comparison is shown in Table 1.

[0039] Table 1 Mechanical parameters

[0040]

[0041] The mineral percentage is obtained by X-ray diffractometer. The minerals can be compared with Table 2.

[0042] Table 2 Minerals See Table

[0043]

[0044] The absolute porosity and effective porosity of each target core were obtained by the helium porosity automatic measuring instrument, and the particle size distribution was obtained by the laser particle size analyzer. The particle size distribution values ​​are mainly divided into three types: fine particle size in the range of 0mm-0.05mm, medium particle size in the range of 0.05mm-0.1mm, and coarse particle size greater than 0.1mm. The physical properties obtained by porosity and particle size distribution are shown in Table 3, as shown below.

[0045] Table 3 Physical properties See Table

[0046]

[0047] Step 103: Calculate the fracture morphological index of the target core according to the downhole core basic parameters. In the embodiment of the present application, the fracture morphological index includes a macro fracture morphological index, a micro weakness direction index and a micro weakness quantity index. According to the downhole core basic parameters of the safety management and evaluation unit production well, the fracture morphological index of the target core of each safety management and evaluation unit production well that affects the safety of the target block of oilfield development is calculated to quantitatively evaluate the stability of the rock. Among them, the macro fracture morphological index is calculated according to the rock mechanics parameters, as follows:

[0048] ;

[0049] In the formula, Represents the morphological index of macro cracks, dimensionless, represents the peak intensity, represents the yield strength, represents the residual strain, represents the peak strain, represents the residual strength, Indicates yield strain. Among them, the macroscopic crack morphology index can more intuitively show the macroscopic rupture degree of the crack.

[0050] The microscopic weakness direction index is calculated based on the particle size distribution and porosity as follows:

[0051] ;

[0052] In the formula, Represents the micro-weakness direction index, dimensionless, Indicates the absolute porosity of the target core, represents the effective porosity of the target core, Indicates the percentage of particles with a particle size distribution in the range of 0mm-0.05mm. Indicates the percentage of particles with a particle size distribution in the range of 0.05mm-0.1mm. It indicates the percentage of particles with a particle size distribution greater than 0.1 mm. Among them, the micro-weakness direction index shows the directionality of the fracture morphology of micro-cracks inside the rock. According to the size of the particle size, it is divided into , , There are three levels, each level is affected by different porosity at the same time. The micro-weakness direction index of each level is calculated separately and the total micro-weakness direction index is accumulated. The larger the value of the micro-weakness direction index, the more fracture directions there are; the smaller the value of the micro-weakness direction index, the fewer fracture directions there are.

[0053] The micro-weakness quantity index is calculated based on the mineral percentage content as follows:

[0054] ;

[0055] In the formula, Represents the number of micro-weaknesses, dimensionless, Represents the total amount of minerals, Indicates the percentage of different minerals. Indicates different types of minerals. It indicates the value when the content of a certain mineral is 100% and the content of other minerals is 0%. The number of microscopic weaknesses, that is, the number of microscopic cracks, is calculated by the distribution difference of the mineral content. The larger the value, the more microscopic cracks there are; the smaller the value, the fewer microscopic cracks there are.

[0056] According to the calculated rock crack morphological index combined with Table 1, Table 2 and Table 3, the rock macro-micro crack performance index Table 4 is obtained.

[0057] Table 4 Rock macro-micro crack performance index

[0058]

[0059] Step 104: Determine the safety management coefficient of the production well of the safety management evaluation unit by combining the fracture morphology index and the downhole core basic parameters. Specifically, the safety management coefficient of the production well of the safety management evaluation unit is calculated according to the macro-micro fracture index of the rock and the downhole core basic parameters, and the level is divided to quantitatively evaluate the safety risk of the production well of the safety management evaluation unit, so as to analyze the safety of the production well of the safety management evaluation unit when the casing is changed, thereby achieving the evaluation purpose of oilfield safety management. Considering the influence of the actual state of confining pressure on the effectiveness of micro-weaknesses, its correction index is calculated as follows:

[0060] ;

[0061] in, ;

[0062] In the formula, express The micro-weakness correction index at , dimensionless, express The micro-weakness correction index at , dimensionless, represents the peak intensity, represents the residual strength, represents the residual strain, represents the peak strain, Indicates no confining pressure correction factor, dimensionless, It represents the peak strength value when there is no confining pressure, dimensionless, It represents the residual strength value when there is no confining pressure, which is dimensionless. represents the residual strain when there is no confining pressure, Indicates the peak strain when there is no confining pressure. According to the actual confining pressure, the development of micro-cracks is defined, and the micro-weakness correction index is calculated to correct the development morphology of micro-cracks. The mechanical parameters of each reservoir core without confining pressure are shown in Table 5.

[0063] Table 5 Unconfined pressure parameters

[0064]

[0065] The safety management coefficient is calculated by combining macro and micro influences, and is divided into levels according to its size. The safety risk assessment is conducted on the wellhead of the production well of each level of safety management evaluation unit. The safety management coefficient is as follows:

[0066] ;

[0067] In the formula, represents the safety management factor, dimensionless, Represents the morphological index of macro cracks, dimensionless, Represents the micro-weakness direction index, dimensionless, express and The micro-weakness correction index in both cases is dimensionless, It represents the number index of micro weaknesses and has no dimension. The table of safety management coefficients is shown in Table 6.

[0068] Table 6 Safety management coefficient table

[0069]

[0070] Step 105: Classify the risk levels of the production wells in the safety management evaluation unit according to the safety management coefficient to quantitatively evaluate their safety risks. Figure 2 This is a comparison chart of the safety management coefficients of the production wells in the safety management evaluation unit. Specifically, the production wells in the safety management evaluation unit are divided into the following four levels:

[0071] .

[0072] Although the present application provides method operation steps as described in the embodiments or flowcharts, more or fewer operation steps may be included based on conventional or non-creative labor. The order of steps listed in this embodiment is only one way of executing the order of many steps and does not represent the only execution order. When the actual device or client product is executed, it can be executed in sequence or in parallel according to the method shown in this embodiment or the accompanying drawings (for example, in a parallel processor or multi-threaded processing environment).

[0073] like Figure 3 As shown, the embodiment of the present application also provides an oilfield safety management evaluation device 300. The device includes: a unit division module 301, a data acquisition module 302, a parameter calculation module 303 and a risk evaluation module 304, which are specifically as follows.

[0074] The unit division module 301 is used to divide the target development blocks of the oil field to obtain safety management evaluation unit production wells.

[0075] The data acquisition module 302 is used to obtain the downhole core basic parameters of the production well of the safety management and evaluation unit.

[0076] The parameter calculation module 303 is used to calculate the fracture morphology index of the target core according to the downhole core basic parameters.

[0077] The safety management coefficient of the production well in the safety management evaluation unit is determined by combining the fracture morphology index and the downhole core basic parameters.

[0078] The risk assessment module 304 is used to classify the risk levels of the production wells in the safety management assessment unit according to the safety management coefficients, so as to quantitatively assess their safety risks.

[0079] The devices or modules described in the above embodiments can be implemented by computer chips or entities, or by products with certain functions. For the convenience of description, the above devices are described in various modules according to their functions. When implementing this application, the functions of each module can be implemented in the same or multiple software and / or hardware. Of course, the module that implements a certain function can also be implemented by combining multiple sub-modules or sub-units.

[0080] The method, device or module in the present application can be implemented in the form of a computer-readable program code. The controller can be implemented in any appropriate manner. For example, the controller can take the form of a microprocessor or processor and a computer-readable medium storing a computer-readable program code (such as software or firmware) that can be executed by the (micro)processor, a logic gate, a switch, an application-specific integrated circuit (English: Application Specific Integrated Circuit; Abbreviation: ASIC), a programmable logic controller and an embedded microcontroller. Examples of controllers include but are not limited to the following microcontrollers: ARC 625D, AtmelAT91SAM, Microchip PIC18F26K20 and Silicone Labs C8051F320. The memory controller can also be implemented as part of the control logic of the memory. Those skilled in the art also know that in addition to implementing the controller in a purely computer-readable program code, the controller can be implemented in the form of a logic gate, a switch, an application-specific integrated circuit, a programmable logic controller and an embedded microcontroller by logically programming the method steps. Therefore, this controller can be considered as a hardware component, and the devices included in it for implementing various functions can also be regarded as structures within the hardware component. Or even, the means for realizing various functions may be regarded as both a software module for realizing the method and a structure within a hardware component.

[0081] An embodiment of the present application also provides a device for executing an evaluation method for oilfield safety management, the device comprising: a processor; a memory for storing processor executable instructions; when the processor executes the executable instructions, the method of the embodiment of the present application is implemented.

[0082] In addition, each functional module in each embodiment of the present application may be integrated into one processing module, or each module may exist independently, or two or more modules may be integrated into one module.

[0083] It can be known from the description of the above implementation mode that those skilled in the art can clearly understand that the present application can be implemented by means of software plus necessary hardware. Based on such an understanding, the technical solution of the present application can be essentially or partly reflected in the prior art in the form of a software product, or it can be reflected in the implementation process of data migration. The computer software product can be stored in a storage medium, such as ROM / RAM, a disk, an optical disk, etc., including a number of instructions for a computer device (which can be a personal computer, a mobile terminal, a server, or a network device, etc.) to execute the methods of each embodiment of the present application or some parts of the embodiments.

[0084] The various embodiments in this specification are described in a progressive manner, and the same or similar parts between the various embodiments can be referred to each other, and each embodiment focuses on the differences from other embodiments. All or part of this application can be used in many general or special computer system environments or configurations. For example: personal computers, server computers, handheld devices or portable devices, tablet devices, mobile communication terminals, multi-processor systems, microprocessor-based systems, programmable electronic devices, network PCs, minicomputers, mainframe computers, distributed computing environments including any of the above systems or devices, etc.

[0085] The above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit the present application. Although the present application has been described in detail with reference to the aforementioned embodiments, a person of ordinary skill in the art should understand that the technical solutions described in the aforementioned embodiments may still be modified, or some or all of the technical features thereof may be replaced by equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the present application.

Claims

1. A method for evaluating oilfield safety management, characterized in that: include: Divide the target development blocks of the oil field to obtain production wells of safety management evaluation units; Obtaining downhole core basic parameters of the production well of the safety management and evaluation unit; Obtaining the target core and its stress-strain curve of the production well of the safety management and evaluation unit, and the rock mechanics parameters of the target core; Obtain the mineral percentage, porosity and particle size distribution of the target core; The fracture morphological index of the target core is calculated according to the downhole core basic parameters; the fracture morphological index includes a macro fracture morphological index, a micro weakness direction index and a micro weakness quantity index; wherein the macro fracture morphological index is calculated according to the rock mechanics parameters, the micro weakness direction index is calculated according to the particle size distribution and the porosity, and the micro weakness quantity index is calculated according to the mineral percentage content; the macro fracture morphological index includes: ； In the formula, It represents the morphological index of the macro crack, dimensionless, represents the peak intensity, represents the yield strength, represents the residual strain, represents the peak strain, represents the residual strength, represents the yield strain; The micro-weakness direction index includes: ； In the formula, represents the micro-weakness direction index, dimensionless, Indicates the absolute porosity of the target core, represents the effective porosity of the target core, Indicates the percentage of particles with a particle size distribution in the range of 0mm-0.05mm. Indicates the percentage of particles with a particle size distribution in the range of 0.05mm-0.1mm. Indicates the percentage of particles with a particle size distribution greater than 0.1 mm; The micro-weakness quantity index includes: ； In the formula, Represents the number index of micro-weaknesses, dimensionless, Represents the total amount of minerals, Indicates the percentage of different minerals. Indicates different types of minerals. Indicates the value when one mineral is 100% and other minerals are 0%; Before determining the safety management coefficient of the production well of the safety management evaluation unit by combining the fracture morphology index with the downhole core basic parameters, the method further includes: performing a correction index on the microscopic weaknesses of the target core according to the confining pressure state of the target core to quantitatively evaluate the stability of the rock, including: ； in, ; In the formula, express The micro-weakness correction index at , dimensionless, express The micro-weakness correction index at , dimensionless, represents the peak intensity, represents the residual strength, represents the residual strain, represents the peak strain, Indicates no confining pressure correction factor, dimensionless, It represents the peak strength value when there is no confining pressure, dimensionless, It represents the residual strength value when there is no confining pressure, which is dimensionless. represents the residual strain when there is no confining pressure, represents the peak strain when there is no confining pressure; Determine the safety management coefficient of the production well of the safety management evaluation unit by combining the fracture morphology index and the downhole core basic parameters; The production wells in the safety management evaluation unit are classified into risk levels according to the safety management coefficient to quantitatively evaluate their safety risks.

2. The method according to claim 1, characterized in that The safety management coefficient of the production well of the safety management evaluation unit is determined by combining the fracture morphology index with the downhole core basic parameters as follows: ； In the formula, represents the safety management factor, dimensionless, Represents the morphological index of macro cracks, dimensionless, Represents the micro-weakness direction index, dimensionless, express and The micro-weakness correction index in both cases is dimensionless, Represents the number of micro weaknesses, dimensionless.

3. An evaluation device for oilfield safety management, characterized in that: include: Unit division module, used to divide the target development blocks of the oil field to obtain safety management evaluation unit production wells; A data acquisition module is used to acquire the downhole core basic parameters of the production well of the safety management and evaluation unit; acquire the target core and its stress-strain curve of the production well of the safety management and evaluation unit, and the rock mechanics parameters of the target core; Obtain the mineral percentage, porosity and particle size distribution of the target core; A parameter calculation module is used to calculate the fracture morphological index of the target core according to the downhole core basic parameters; the fracture morphological index includes a macro fracture morphological index, a micro weakness direction index and a micro weakness quantity index; wherein the macro fracture morphological index is calculated according to the rock mechanics parameters, the micro weakness direction index is calculated according to the particle size distribution and the porosity, and the micro weakness quantity index is calculated according to the mineral percentage content; the macro fracture morphological index includes: ； In the formula, It represents the morphological index of the macro crack, dimensionless, represents the peak intensity, represents the yield strength, represents the residual strain, represents the peak strain, represents the residual strength, represents the yield strain; The micro-weakness direction index includes: ； In the formula, represents the micro-weakness direction index, dimensionless, Indicates the absolute porosity of the target core, represents the effective porosity of the target core, Indicates the percentage of particles with a particle size distribution in the range of 0mm-0.05mm. Indicates the percentage of particles with a particle size distribution in the range of 0.05mm-0.1mm. Indicates the percentage of particles with a particle size distribution greater than 0.1 mm; The micro-weakness quantity index includes: ； In the formula, Represents the number index of micro-weaknesses, dimensionless, Represents the total amount of minerals, Indicates the percentage of different minerals. Indicates different types of minerals. Indicates the value when one mineral is 100% and other minerals are 0%; Before determining the safety management coefficient of the production well of the safety management evaluation unit by combining the fracture morphology index with the downhole core basic parameters, the method further includes: performing a correction index on the microscopic weaknesses of the target core according to the confining pressure state of the target core to quantitatively evaluate the stability of the rock, including: ； in, ; In the formula, express The micro-weakness correction index at , dimensionless, express The micro-weakness correction index at , dimensionless, represents the peak intensity, represents the residual strength, represents the residual strain, represents the peak strain, Indicates no confining pressure correction factor, dimensionless, It represents the peak strength value when there is no confining pressure, dimensionless, It represents the residual strength value when there is no confining pressure, which is dimensionless. represents the residual strain when there is no confining pressure, represents the peak strain when there is no confining pressure; Determine the safety management coefficient of the production well of the safety management evaluation unit by combining the fracture morphology index and the downhole core basic parameters; The risk assessment module is used to classify the risk levels of the production wells in the safety management assessment unit according to the safety management coefficient so as to quantitatively assess the safety risks thereof.

4. A device for executing an evaluation method for oilfield safety management, characterized in that: include: processor; a memory for storing processor-executable instructions; When the processor executes the executable instructions, the method according to any one of claims 1 to 2 is implemented.

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