A detection arrangement method for combustible gas leakage on an offshore platform

Abstract

The present invention relates to a method for arranging a detection arrangement of a flammable gas leak on an offshore platform, comprising the following steps: S1, combining the process leakage frequency of the offshore platform, analyzing the law of the diffusion of flammable gas leaks and the characteristics of their distribution range under different types through numerical simulation; S2, forming a flammable gas diffusion distribution coordinate data set of a potential leakage point; S3, drawing the process area into a grid to form a matrix diagram, and combining it with the flammable gas diffusion distribution coordinate data set to form a leakage source influence matrix; S4, statistically analyzing all leakage source influence matrices to obtain the optimal arrangement of flammable gas leak detection. The present invention integrates and optimizes the data in combination with the diffusion distribution after the flammable gas leak, and proposes a matrix marking method to obtain a method for accumulating and processing diffused gas clouds under different leakage frequencies, thereby forming an optimal detection arrangement, so as to provide a quantitative reference basis for the flammable detection arrangement.

Description

Technical Field

[0001] The present invention relates to the field of offshore oil safety design and production safety technology, and in particular to an analysis and evaluation method for monitoring and designing and optimizing flammable gas leakage in a process area of ​​an offshore platform. Background Art

[0002] Energy security is one of the important foundations for the development of my country's energy strategic planning. As the energy industry continues to change, technological innovation and engineering exploration continue to deepen and develop, safe, environmentally friendly, healthy and orderly development is the key factor in maintaining sustained and steady growth in energy development.

[0003] "High risk" is one of the three high problems faced by offshore oil development. The medium handled and transported by offshore oil platforms is flammable and explosive hydrocarbons. Once a leak occurs, it is very easy to cause fire and explosion when it comes into contact with ignition sources. In addition, if the medium contains toxic and harmful gases such as hydrogen sulfide and carbon monoxide, there is also a potential risk of poisoning and suffocation of personnel. According to statistics on offshore oil accidents in the North Sea, the Gulf of Mexico and my country, leaks, fires and explosions are one of the main factors threatening the safety of offshore platforms.

[0004] Therefore, it is particularly important to detect the leak within a short period of time after the initial leak occurs, so that the staff can know the location and situation of the leak at the first time, so as to take scientific and reasonable measures to shut down and isolate the leak accordingly, and avoid the risk of fire and explosion caused by the leak. Summary of the invention

[0005] In view of this, the present invention aims to provide a detection arrangement method for combustible gas leakage on an offshore platform, so as to know the location and situation of the leakage as early as possible, so as to take scientific and reasonable measures to avoid the risk of fire and explosion caused by the leakage.

[0006] The present invention provides a method for detecting flammable gas leakage on an offshore platform, the method comprising the following steps:

[0007] S1. Combined with the leakage frequency of offshore platform technology, numerical simulation is used to analyze the diffusion law and distribution range characteristics of flammable gas leakage under different types;

[0008] S2, forming a combustible gas diffusion distribution coordinate data set of potential leakage points;

[0009] S3, drawing the process area into a grid to form a matrix diagram, and combining it with the combustible gas diffusion distribution coordinate data set to form a leakage source influence matrix;

[0010] S4. Perform statistical analysis on the impact matrix of all leakage sources to obtain the optimal layout of combustible gas leak detection.

[0011] According to one embodiment of the present invention, step S1 further includes:

[0012] The offshore oil platform process flow is divided into different process sub-units, the physical parameters and process parameters of the leakage source of each process sub-unit are counted, and the leakage frequency of the leakage source is calculated in combination with the leakage database of the leakage source.

[0013] According to one embodiment of the present invention, step S1 further includes:

[0014] The leakage frequency of the leakage source is corrected and classified and analyzed: based on the facility operation data at the facility site, the original data of the operation time and failure time of the leakage source are counted as prior data; the Bayesian decision is used to predict the posterior data to form the failure probability of the leakage facility, and the leakage frequency of the leakage source is further corrected; the leakage source items with similar locations and consistent leakage diffusion plumes are merged and classified.

[0015] According to an implementation manner of the present invention, step S1 further comprises: using a CFD analysis method to perform simulation analysis on the leakage diffusion.

[0016] According to one embodiment of the present invention, when performing the simulation analysis, the leakage is divided into small leakage, medium leakage, large leakage, and large leakage, and the leakage direction is determined according to the leakage characteristics of the leakage source, and the simulation analysis of the smoke plume is carried out in combination with the wind frequency and wind speed data.

[0017] According to one embodiment of the present invention, step S2 further includes:

[0018] The simulation results of the smoke plume are analyzed for regularities and characteristics, the smoke plume path is determined, and similar paths are merged and sorted to form a coordinate data set corresponding to the leakage source, each of which corresponds to a corresponding probability value.

[0019] According to one embodiment of the present invention, step S3 further includes:

[0020] The offshore platform process area is divided into a grid to form a plurality of space modules, and all the space modules are marked to form a space matrix.

[0021] According to one embodiment of the present invention, step S3 further includes:

[0022] The coordinate data set of the leakage source is matched with the spatial matrix to form the leakage source influence matrix.

[0023] According to one embodiment of the present invention, step S4 further includes:

[0024] The element items in the leakage source impact matrix are screened and sorted according to the number of identical elements. The spatial matrix positions corresponding to the identical elements are the preliminary positions of the detection arrangement, and the diffusion impact matrix involving the preliminary positions is deleted.

[0025] According to one embodiment of the present invention, step S4 further includes:

[0026] The probabilities of the preliminary selected positions are screened and analyzed, and the preliminary selected positions for leak detection that are higher than the acceptable standard values ​​of the leak detection probability are used as the final layout positions.

[0027] The present invention integrates and optimizes the data based on the diffusion distribution after the combustible gas leak, and proposes a matrix marking method to obtain the method for accumulating the diffused gas cloud under different leakage frequencies, so as to form the optimal detection layout, so as to provide a quantitative reference basis for the combustible detection layout. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 It is a schematic diagram of dividing all the process units involving oil and gas leakage in the process flow of an embodiment of the present invention;

[0029] Figure 2 A schematic diagram of frequency calculation according to an embodiment of the present invention;

[0030] Figure 3 This is a statistical diagram of a leakage source coordinate data set according to an embodiment of the present invention;

[0031] Figure 4 A schematic diagram of a diffusion matrix of a leakage source term according to an embodiment of the present invention;

[0032] Figure 5 A schematic diagram of the deletion principle of the diffusion matrix of leakage source terms according to an embodiment of the present invention;

[0033] Figure 6 The figure is a flow chart of a method for detecting flammable gas leakage on an offshore platform according to an embodiment of the present invention. DETAILED DESCRIPTION

[0034] The preferred embodiments of the present invention will be described in detail below in conjunction with the accompanying drawings so that the purpose, features and advantages of the present invention can be more clearly understood. It should be understood that the embodiments shown in the accompanying drawings are not intended to limit the scope of the present invention, but are only intended to illustrate the essential spirit of the technical solution of the present invention.

[0035] The gas diffusion after oil and gas leakage is affected by many factors: the location of the leak, the direction of the leak, the leak rate, and environmental conditions. Therefore, how to comprehensively consider the combined effects of these factors to study the layout of the combustible gas detection position is a key issue to be solved. According to the randomness and uncertainty of the accident, in principle, any leakage situation may occur. In order to solve the uncontrollable leakage condition caused by different combinations, the present invention uses the leakage frequency as a benchmark to determine the leakage condition combination to be considered. The present invention integrates and optimizes the data in combination with the diffusion distribution after the combustible gas leak, so as to form the optimal detection layout. Therefore, the present invention attempts to propose a matrix marking method to obtain a method for accumulating the diffusion gas cloud under different leakage frequencies, thereby providing a quantitative reference basis for the combustible detection layout.

[0036] The present invention discloses a research method based on the matrix layout of combustible gas leakage on offshore platforms. Combined with the frequency of process leakage on offshore platforms, the law of diffusion of combustible gas leakage and its distribution range characteristics under different types are analyzed through numerical simulation to form a combustible gas diffusion distribution coordinate data set of potential leakage points. The process area is drawn into a grid to form a matrix diagram, which is combined with the combustible gas diffusion coordinate data set to form a leakage source influence matrix. The optimal layout of combustible gas detection can be sorted out by performing statistical analysis on the influence matrices of all leakage sources. The process of the method is as follows: Figure 6 shown.

[0037] One embodiment of the present invention mainly includes the following steps:

[0038] (1) The offshore oil platform process flow is divided into different process sub-units, and the leakage source items of each process sub-unit as well as the physical parameters and process parameters of the leakage source are counted. The leakage frequency of the leakage source is calculated by combining the leakage database of the leakage source items.

[0039] (2) Correct and classify the leakage frequency of the leakage source. Based on the facility operation data at the facility site, the original data of the leakage facility operation time and failure time are counted as prior data. The Bayesian decision is used to predict the posterior data to form the failure probability of the leakage facility, and further correct the leakage frequency of the leakage source item. On this basis, the leakage source items with similar leakage source locations and basically the same leakage diffusion plume are merged and classified.

[0040] (3) Combined with CFD (fluid analysis) methods, simulation analysis of leakage diffusion is performed. For example, leakage is divided into small leakage (<1kg / s), medium leakage (1-10kg / s), large leakage (10-30kg / s) and large leakage (>30kg / s). At the same time, according to the leakage characteristics of the leakage source, the leakage direction is determined (divided into front, back, left, right, up and down), and the simulation analysis of the smoke plume is carried out in combination with wind frequency and wind speed data.

[0041] (4) The process area is divided into a grid. The size of the grid may be, for example, a space module of 0.25 m × 0.25 m × 0.25 m. All the space modules are marked to form a space matrix.

[0042] (5) Analyze the patterns and characteristics of the simulation results of the smoke plume to determine the path of the smoke plume (the smoke plume is determined by the lower limit of the detection concentration of the detection facility). Merge and organize similar paths to form a coordinate data set corresponding to the leakage source. Each coordinate data set corresponds to a corresponding probability value.

[0043] (6) The coordinate data set of the leakage source term is matched with the spatial matrix to form the diffusion influence matrix of the leakage source term.

[0044] (7) Matlab is used to screen the elements in all diffusion influence matrices and sort them according to the same number of elements. The spatial matrix positions corresponding to the same elements are the preliminary positions of the detection layout, and the diffusion matrices involving the preliminary positions are deleted. Finally, the deletion of the diffusion influence matrices of all leakage source items is completed.

[0045] (8) Further screening and analysis are performed on the probability of the preliminary selected positions to establish an acceptable standard for leak detection, such as 1E-04. The preliminary selected leak detection positions above this value are used as the final positions. Finally, all detection positions are determined.

[0046] The present invention provides a research method based on the matrix-type offshore platform combustible gas leakage layout, based on the calculation of leakage frequency and numerical simulation analysis of CFD (fluid analysis) software, combined with the leakage source influence matrix, to form a decision basis for combustible gas detection layout, providing an analytical basis for the detection layout.

[0047] Example

[0048] This embodiment provides a research method based on the matrix-type offshore platform combustible gas leakage arrangement, including the following steps:

[0049] (1) The offshore oil platform process flow is divided into different process sub-units, and the leakage source items, physical parameters and process parameters of each process sub-unit are counted. Combined with the leakage database of the process sub-unit, the leakage frequency of the leakage source is calculated.

[0050] It is advisable to use the ESD valve as the dividing line between the two sub-units, divide all processes involving oil and gas leakage in the process into several sub-units, and collect data on the leakage source facility type, size, pipe diameter, medium component, flow rate, pressure, etc. Combined with the leakage database, calculate the leakage frequency of each item. The analysis process and frequency calculation are as follows: Figure 1 , 2 As shown. PID&PFD represents process flow diagram.

[0051] (2) Correct and classify the leakage frequency of the leakage source. Based on the facility operation data at the facility site, the original data of the leakage facility operation time and failure time are counted as prior data. The Bayesian decision is used to predict the posterior data to form the failure probability of the leakage facility, and further correct the leakage frequency of the leakage source item. On this basis, the leakage source items with similar leakage source locations and basically the same leakage diffusion plume are merged and classified.

[0052] In order to ensure the accuracy of the leakage frequency data, the failure frequency is corrected in combination with the data from the operation site. The on-site operation data of the offshore platform can be obtained in the form of Table 1.

[0053] Table 1 Statistics of facility operation

[0054]

[0055] Apply Bayesian theorem to analyze field data:

[0056]

[0057] The reliability estimation of the posterior data is iteratively calculated in the Matlab environment to obtain the failure data of the facilities of interest. The data calculated in process (1) is then corrected to finally obtain the failure frequencies of different facilities.

[0058] (3) Combined with CFD method, simulation analysis of leakage diffusion is carried out. Leaks are divided into small leaks (<1kg / s), medium leaks (1-10kg / s), large leaks (10-30kg / s) and large leaks (>30kg / s). At the same time, according to the leakage characteristics of the leakage source, the leakage direction is determined (divided into front, back, left, right, up and down), and the simulation analysis of the smoke plume is carried out in combination with wind frequency and wind speed data.

[0059] (4) The process area is divided into a grid with a size of 0.25 m × 0.25 m × 0.25 m space module. All space modules are marked to form a space matrix.

[0060] (5) Analyze the rules and characteristics of the simulation results of the smoke plume, determine the path of the smoke plume (the smoke plume is determined by the detection concentration lower limit of the detection facility), merge and organize similar paths to form a coordinate data set corresponding to the leakage source. Each coordinate data set corresponds to a corresponding probability value, such as Figure 3 As shown, the diagram shows that the process system space is divided according to three-dimensional coordinates (x, y, z) and grids, and the coverage of smoke diffusion is plotted on the coordinates, thereby conveniently obtaining the grid covered by the leaking combustible gas.

[0061] (6) The coordinate data set of the leakage source term is matched with the spatial matrix to form the diffusion matrix of the leakage source term. Figure 4 As shown in the figure, S1FSC1 represents the small compressor leakage condition 1 with the leakage direction of subunit 1 being forward (S1 indicates subunit, F indicates the leakage direction is forward, S indicates small leakage, and C1 indicates compressor leakage. In actual operation, the naming can be based on custom). The symbols in the matrix represent the range covered by the flue gas, and the grids are all A m,n To express.

[0062] (7) Use Matlab to screen the elements in all diffusion matrices and sort them by the same number of elements. The spatial matrix positions corresponding to the same elements are the preliminary positions for detection layout, and the diffusion matrices involving the preliminary positions are deleted, and finally the deletion of the diffusion matrices of all leakage source items is completed. Figure 5 As shown, the grids affected by different leakage conditions may overlap, which means that setting up a detection arrangement in the overlapping area can meet the monitoring of these leaks. Therefore, the union area of ​​multiple leaks is the preferred area for the detection arrangement.

[0063] (8) Further screening and analysis of the probability of the preliminary selected positions is performed to establish the acceptable standard for leak detection: 1E-04. The preliminary selected layout of leak detection above this value is used as the final layout position. Finally, the determination of all detection layout positions is formed.

[0064] A probability superposition analysis is performed on the preferred elements of the diffusion matrix of all deleted leakage source items, and the elements with probability values ​​greater than 1E-04 are selected as the final detection layout positions.

[0065] The above embodiments are only used to illustrate the present invention, wherein the components, devices or steps and sequences of the embodiments can be changed, and each implementation method can be combined or deleted as needed. Not all components in the drawings are necessary. The general principles defined in this document can be implemented in other embodiments without departing from the spirit or scope of this application. Therefore, this application will not be limited to the embodiments described herein, and any equivalent transformations and improvements based on the technical solution of the present invention should not be excluded from the protection scope of the present invention.

Claims

1. A method for detecting flammable gas leaks on an offshore platform, characterized in that: The method comprises the following steps: S1. Divide the process flow of the offshore oil platform into different process sub-units, count the physical parameters and process parameters of the leakage source of each process sub-unit, and calculate the leakage frequency of the leakage source in combination with the leakage database of the leakage source; correct and classify the leakage frequency of the leakage source: based on the facility operation data at the facility site, count the original data of the operation time and failure time of the leakage source as prior data; use Bayesian decision to predict the posterior data to form the failure probability of the leakage facility, and further correct the leakage frequency of the leakage source; combine the leakage frequency of the offshore platform process, use the CFD analysis method to simulate and analyze the leakage diffusion, and analyze the law of the diffusion of combustible gas under different types and its distribution range characteristics through numerical simulation; S2. Merge and classify the leakage source items with similar leakage source locations and consistent leakage diffusion plumes; analyze the rules and characteristics of the simulation results of the plumes, determine the plume paths, merge and organize similar paths, and form a coordinate data set corresponding to the leakage source, each of which corresponds to a corresponding probability value; form a combustible gas diffusion distribution coordinate data set of potential leakage points; S3, drawing the process area into a grid to form a matrix diagram of multiple space modules, dividing the offshore platform process area into grids, marking all the space modules, and matching the coordinate data set of the leakage source with the space matrix to form a leakage source impact matrix; S4. Perform statistical analysis on all leakage source impact matrices, screen the elements in the leakage source impact matrix, and sort them by the number of identical elements. The spatial matrix positions corresponding to the identical elements are the preliminary positions for detection layout. The diffusion impact matrix, i.e., the probability, involving the preliminary positions is deleted, screened, and analyzed. The preliminary positions for leakage detection that are higher than the acceptable standard value of the leakage detection probability are used as the final layout positions, thereby obtaining the optimal layout for combustible gas leakage detection.

2. The method for detecting flammable gas leakage on an offshore platform according to claim 1, characterized in that: When performing the simulation analysis, the leak is divided into small leaks, medium leaks, large leaks, and large leaks. The leak direction is determined based on the leak characteristics of the leak source, and the simulation analysis of the smoke plume is carried out in combination with wind frequency and wind speed data.

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