Oil and gas well gas leakage detection and early warning system and method based on laser detection

Abstract

The present application relates to a kind of oil and gas well safety monitoring technical field, it is a kind of oil and gas well gas leakage detection and early warning system based on laser detection, method, including laser detection adaptation adjustment unit divides oil and gas well pipe network into several sub-regions, determines the real-time laser type of each sub-region;Laser point position coverage analysis unit determines the laser point position of each sub-region in combination with the real-time laser type of each sub-region;Leakage detection analysis unit determines the pipe network leakage type of each sub-region according to the leakage detection analysis signal after laser detection;Laser detection error analysis unit obtains the laser detection error risk of each sub-region.The present application can match laser type and the type needed to be detected for oil and gas well pipe network, to ensure the effectiveness of oil and gas well pipe network leakage detection, further can determine fault type while detecting gas leakage, facilitate timely pipe network regulation and control, reduce the influence generated by sub-region pipe network gas leakage.

Description

TECHNICAL FIELD

[0001] The application relates to the technical field of oil and gas well safety monitoring, and is an oil and gas well gas leakage detection and early warning system and method based on laser detection. BACKGROUND

[0002] An oil and gas well is an indispensable information and material channel for exploring and developing underground oil and gas resources. Oil and gas well gas leakage detection and early warning is a key link to ensure the safety of oil and gas production. At present, laser remote sensing detection technology is used to detect oil and gas well gas leakage. Laser remote sensing detection technology is to emit a laser beam of a specific wavelength. When the laser interacts with the leaked gas molecules, scattering, absorption and other phenomena occur.

[0003] However, in the prior art, the laser type cannot be set according to the gas type of each sub-region, and the laser emitter point cannot be set according to the position of the sub-region, resulting in low efficiency of gas leakage detection. In addition, the current leakage reason cannot be analyzed and inferred according to the leakage type, so that targeted detection and maintenance cannot be performed.

[0004] There are many gas leakage detection and early warning methods in the prior art, for example:

[0005] Existing patent document one, with the publication number CN120139955A, discloses a waste mine methane source exploration-monitoring-analysis method and system based on air-ground cooperation, which comprises: a high-sensitivity CH4 detection device and a camera are carried on a unmanned aerial vehicle, and the unmanned aerial vehicle is used for aerial inspection according to a flight route, and the methane distribution around the waste mine is explored and inspected through the back transmission of a three-dimensional concentration; a cloud platform laser remote sensing device and a meteorological sensor are arranged at a wellhead, a fissure dense area and a wind flow route, and the monitoring data is transmitted through LoRa / ZigBee; the air-ground data is fused to construct a methane concentration gradient field and a diffusion model, and the leakage trend is predicted in combination with geological and meteorological data for large-scale and continuous monitoring; and the system triggers multi-level early warning and automatically starts emergency response.

[0006] Existing patent document two, with the publication number CN116642140A, discloses a monitoring and inspection system and a leakage early warning method for a gas station pipeline network, which comprises a daily monitoring module for monitoring the gas station pipeline network by arranging fixed equipment; a mobile inspection module for commanding a mobile robot to conduct mobile inspection; and a monitoring and inspection integrated platform for realizing the functional integration of daily monitoring and mobile inspection. When the daily monitoring data or the mobile inspection data detects gas leakage, the result is uploaded to the integrated platform to realize data sharing, a Gaussian plume diffusion model and a hybrid genetic grey wolf algorithm are constructed in advance to simulate the diffusion of the leakage area and inversely calculate the source information, so as to provide the system with leak point positioning, diffusion area prediction, hierarchical early warning and decision control measures.

[0007] The existing published patent document three, the publication number CN119686721A discloses a kind of gas well annular space gas leakage monitoring method and system, method includes determining initial leakage point casing side pressure;Determine the gas leakage flow of leakage point;Determine the time step required to generate a single bubble under gas leakage flow;Sampling is carried out with time step as time interval, obtain the gas column volume and liquid column volume in annular space protective fluid in current time step;Determine target wellhead casing annular space pressure;Determine target leakage point casing side pressure;If target leakage point casing side pressure is less than the pressure in the pipe string at leakage point, then update gas column volume and liquid column volume, and respectively as the gas column volume and liquid column volume of next time step;Repeat obtaining target leakage point casing side pressure until the target leakage point casing side pressure is greater than or equal to the pressure in the pipe string at leakage point, determine that gas leakage in gas well annular space stops.

[0008] But the above method cannot set the laser emitter point in the detection area, and cannot analyze and infer the current leakage reason for the leakage type. SUMMARY

[0009] The present application provides a kind of oil and gas well gas leakage detection and early warning system based on laser detection, method, overcome the deficiency of above-mentioned prior art, it can effectively solve the problem that existing oil and gas well gas leakage detection method cannot set the laser emitter point in the detection area.

[0010] One of the technical solutions of the present application is realized by the following measures: a kind of oil and gas well gas leakage detection and early warning system based on laser detection, including laser detection platform, laser detection platform is connected with laser detection adaptive adjustment unit and laser detection error analysis unit, laser detection platform includes laser point position coverage analysis unit and leakage detection analysis unit;

[0011] Laser detection adaptive adjustment unit, oil and gas well pipe network is divided into several sub-regions, according to the cumulative type of gas transported in each sub-region pipe network determines the type of detection and laser type, using the corresponding laser control information and laser irradiation information, set the real-time laser type of each sub-region by threshold comparison;

[0012] Laser point position coverage analysis unit, in combination with the real-time laser type of each sub-region, use point setting rule to mark the point setting information of preset point, obtain corresponding point setting coefficient, determine the laser point of each sub-region according to the comparison result of point setting coefficient and point setting coefficient threshold, wherein point setting coefficient is as follows:

[0013]

[0014] Wherein, h1, h2, h3 are preset proportion coefficients respectively; β is error correction factor; YC, PLK, XZ are point position setting information respectively;

[0015] The leakage detection analysis unit acquires and determines the pipe network leakage type of each sub-region according to the leakage detection analysis signal after laser detection, generates and sends a warning signal, wherein the leakage detection analysis signal includes leakage concentration difference data and leakage transportation influence data.

[0016] The laser detection error analysis unit compares the concentration error information and the wavelength error information of each sub-region with the maximum sensitivity deviation threshold and the wavelength increase span threshold respectively to obtain the laser detection error risk of each sub-region.

[0017] The following is a further optimization or / and improvement of the above technical solutions:

[0018] The above laser detection adaptive adjustment unit comprises:

[0019] The type determination module divides the oil and gas well pipe network into a plurality of sub-regions, counts the cumulative gas type transported by the pipe network in each sub-region, marks it as a type to be detected, and obtains the laser type that reacts with the type to be detected according to the existing laser emitter;

[0020] The information acquisition module acquires the laser control information and the laser irradiation information corresponding to the type to be detected and the laser type of each sub-region;

[0021] The real-time laser type setting module compares the laser control information and the laser irradiation information of each sub-region with the numerical ratio threshold and the delay time threshold respectively according to the preset real-time laser type analysis rule, and sets the real-time laser type of each sub-region.

[0022] The above real-time laser type analysis rule comprises:

[0023] If the laser control information does not exceed the numerical ratio threshold, or the laser irradiation information exceeds the delay time threshold, it is inferred that the type to be detected of the gas transported by the current sub-region cannot completely adapt to the laser detection, a laser detection risk signal is generated and sent to the laser detection platform, the laser detection platform receives the laser detection risk signal, analyzes the gas type transported by the pipe network of the current sub-region, compares the gas transportation amount and the transportation frequency of the corresponding type, and if any data of the gas transportation amount or the transportation frequency exceeds the set threshold, the corresponding gas type is detected by laser, and the adaptive laser type of the corresponding type is set as the emitted laser type of the laser emitter. The number of laser types is not unique, and when the laser type is converted, the type coverage is performed without delay, otherwise the type is excluded. When the amount of gas transported by the excluded type is small, the corresponding type gas sensor is used for monitoring.

[0024] If the laser control information exceeds the numerical ratio threshold value, and the laser irradiation information exceeds the delay duration threshold value, it is inferred that the current sub-region gas delivery needs to be detected type is fully adapted to the laser detection, and the laser type corresponding to the current sub-region gas delivery is set to the real-time setting type.

[0025] The laser point position coverage analysis unit comprises:

[0026] The preset point position marking module matches the corresponding laser emitter according to the need to detect the type of each sub-region and the real-time laser type, and marks the preset point position of each sub-region based on the coverage area of the laser emitter and the preset point position marking rule, wherein the preset point position marking rule is to overlap the coverage area of the laser emitter with the area of the current corresponding sub-region, and the corresponding point position is marked as the preset point position when the overlapping area is at the peak value.

[0027] The point position setting information marking module marks the point position setting information of the preset point position of each sub-region using the point position setting rule.

[0028] The point position setting coefficient calculation module brings the point position setting information of the preset point position of each sub-region into the point position setting coefficient calculation formula to obtain the corresponding point position setting coefficient.

[0029]

[0030] Wherein, h1, h2, h3 are preset proportion coefficients; YC, PLK, XZ are point position setting information; and β is an error correction factor.

[0031] The laser point position determination module compares the point position setting coefficient corresponding to the preset point position of each sub-region with the point position setting coefficient threshold value, and obtains the laser point position of each sub-region in combination with the laser point position determination rule, wherein the laser point position determination rule comprises:

[0032] If the point position setting coefficient of the preset point position exceeds the point position setting coefficient threshold value, the preset point position of the current sub-region cannot be used as a setting point position, the preset point position of the sub-region is offset, and the offset point position is set as the laser point position.

[0033] If the point position setting coefficient of the preset point position does not exceed the point position setting coefficient threshold value, the preset point position of the current sub-region is used as a setting point position, and the preset point position of the sub-region is set as the laser point position.

[0034] The point position setting rule comprises:

[0035] When the preset point position emits laser to any position in the sub-region, the frequency of the reciprocating delay duration of the corresponding laser emission period in different regional environments is marked as YC.

[0036] acquire the frequency span ratio between the frequency span of the increased frequency of maintenance of the laser transmitter corresponding to the sub-region where the laser transmitter is put into operation and the frequency span of the increased frequency of detection of the leaked gas, and mark it as PLK;

[0037] acquire the time ratio between the time consumed for debugging the matched laser transmitter when the type of the gas transported in the sub-region is changed and the duration after the type of the gas is changed, and mark it as XZ.

[0038] The above leakage detection analysis unit comprises:

[0039] A leakage detection analysis signal acquisition module is configured to acquire the leakage detection analysis signal of each sub-region, wherein the leakage detection analysis signal comprises leakage concentration difference data and leakage transportation influence data, the leakage concentration difference data is the floating span of the concentration difference of the corresponding type of gas inside and outside the pipeline before and after the detection leakage moment of the leakage position of the pipeline network in the sub-region, and the leakage transportation influence data is the sum of the corresponding spans of the pressure reduction span of the gas transportation in the pipeline at the corresponding position after the appearance of the leakage position of the pipeline network and the concentration rise span of the gas outside the pipeline.

[0040] A leakage type determination module is configured to compare the leakage detection analysis signal of each sub-region with the concentration difference floating span threshold value and the pressure-concentration span threshold value respectively, determine the pipeline network leakage type of each sub-region in combination with the pipeline network leakage type judgment rule, and generate and send a maintenance warning signal.

[0041] The above pipeline network leakage type judgment rule comprises:

[0042] If the floating span of the concentration difference of the corresponding type of gas inside and outside the pipeline before and after the detection leakage moment of the leakage position of the pipeline network in the sub-region exceeds the concentration difference floating span threshold value, and the sum of the corresponding spans of the pressure reduction span of the gas transportation in the pipeline at the corresponding position after the appearance of the leakage position of the pipeline network and the concentration rise span of the gas outside the pipeline exceeds the pressure-concentration span threshold value, then the pipeline leakage type of the sub-region is instantaneous leakage with high leakage influence, and a rupture warning signal is generated and sent.

[0043] If the floating span of the concentration difference of the corresponding type of gas inside and outside the pipeline before and after the detection leakage moment of the leakage position of the pipeline network in the sub-region does not exceed the concentration difference floating span threshold value, and the sum of the corresponding spans of the pressure reduction span of the gas transportation in the pipeline at the corresponding position after the appearance of the leakage position of the pipeline network and the concentration rise span of the gas outside the pipeline exceeds the pressure-concentration span threshold value, then the pipeline leakage type of the sub-region is continuous leakage with high leakage influence, and a large-scale warning signal is generated and sent.

[0044] If the floating span of the concentration difference of the corresponding type of gas before and after the detection of the leakage time of the leakage position of the pipe network in the sub-region exceeds the concentration difference floating span threshold, and the sum of the corresponding spans of the pressure drop span of the gas in the pipe at the corresponding position after the occurrence of the leakage position of the pipe network and the concentration rise span of the gas outside the pipe does not exceed the pressure concentration span threshold, then this type of situation does not exist, and the large concentration difference floating span will cause the concentration of the gas outside the pipe to rise;

[0045] If the floating span of the concentration difference of the corresponding type of gas before and after the detection of the leakage time of the leakage position of the pipe network in the sub-region does not exceed the concentration difference floating span threshold, and the sum of the corresponding spans of the pressure drop span of the gas in the pipe at the corresponding position after the occurrence of the leakage position of the pipe network and the concentration rise span of the gas outside the pipe does not exceed the pressure concentration span threshold, then the leakage type of the pipe in the sub-region is continuous leakage and low leakage impact, and a maintenance warning signal is generated and sent.

[0046] The laser detection error analysis unit comprises:

[0047] The error analysis data acquisition module acquires concentration error information and wavelength error information of each sub-region, wherein the concentration error information is a maximum deviation value of the laser detection sensitivity of the corresponding leakage gas type when the real-time leakage concentration span of the corresponding leakage gas type in the sub-region exceeds a set threshold; and the wavelength error information is a wavelength increase span of the laser spectrum absorption repeating part when the gas type of the pipe region corresponding to any laser detection leakage position of the pipe network in the sub-region is not a single type.

[0048] The error risk judgment module compares the concentration error information and the wavelength error information of each sub-region with the maximum deviation threshold of the sensitivity and the wavelength increase span threshold respectively, and obtains the laser detection error risk of each sub-region according to the error risk judgment rule.

[0049] The error risk judgment rule comprises:

[0050] If the maximum deviation value of the laser detection sensitivity of the corresponding leakage gas type when the real-time leakage concentration span of the corresponding leakage gas type in the sub-region exceeds a set threshold exceeds the maximum deviation threshold of the sensitivity, or the wavelength increase span of the laser spectrum absorption repeating part when the gas type of the pipe region corresponding to any laser detection leakage position of the pipe network in the sub-region is not a single type exceeds the wavelength increase span threshold, then the laser detection error risk of the sub-region is high, and the pipe position in the sub-region needs to be re-inspected;

[0051] If the maximum deviation value of the laser detection sensitivity of the corresponding leakage gas type does not exceed the sensitivity maximum deviation threshold value when the real-time leakage concentration span of the corresponding leakage gas type of the sub-region exceeds the set threshold value, and the gas type of the pipeline region corresponding to the arbitrary laser detection leakage position of the sub-region is not a single type, and the wavelength increase span of the repeated part of the laser spectrum absorption does not exceed the wavelength increase span threshold value, then the laser detection error risk of the sub-region is low, and the laser detection of the sub-region is continued.

[0052] The second technical solution of the present application is realized by the following measures: an oil and gas well gas leakage detection and early warning method based on laser detection, comprising

[0053] The oil and gas well pipeline network is divided into several sub-regions by using the laser detection adaptive adjustment unit, the type to be detected and the laser type are determined according to the cumulative type of the gas transported by the pipeline network in each sub-region, and the real-time laser type of each sub-region is set by threshold comparison through the corresponding laser control information and laser irradiation information.

[0054] The laser point position coverage analysis unit is used to determine the laser point position of each sub-region by combining the real-time laser type of each sub-region, using point position setting information to mark the preset point position according to the point position setting rule, and obtaining the corresponding point position setting coefficient according to the comparison result of the point position setting coefficient and the point position setting coefficient threshold value, wherein the point position setting coefficient is as follows:

[0055]

[0056] Wherein, h1, h2, h3 are preset proportion coefficients; β is an error correction factor; YC, PLK, XZ are point position setting information;

[0057] The leakage detection analysis unit is used to determine the pipeline leakage type of each sub-region according to the leakage detection analysis signal, generate and send an early warning signal, and the leakage detection analysis signal includes leakage concentration difference data and leakage transportation influence data.

[0058] The laser detection error analysis unit is used to compare the concentration error information and the wavelength error information of each sub-region with the sensitivity maximum deviation threshold value and the wavelength increase span threshold value respectively, and obtain the laser detection error risk of each sub-region.

[0059] The beneficial effects of the present application are:

[0060] The laser detection adaptive adjustment unit matches the laser type with the type to be detected for the oil and gas well pipe network, and through reasonable matching, it can ensure that the pipelines in each sub-region of the oil and gas well pipe network can accurately detect different types of gas when conveying gas, thereby ensuring the effectiveness of the oil and gas well pipe network leakage detection, ensuring the timeliness of the oil and gas well pipe network leakage detection, improving the feasibility of the oil and gas well pipe network laser detection, avoiding the inadaptation of the laser type to the current leakage gas, causing the detection data to deviate, and affecting the gas conveying efficiency of the oil and gas well pipe network.

[0061] The laser point position coverage analysis unit plans the laser point position coverage area of the sub-region, and through reasonable planning of the laser point position coverage area, the detection accuracy of the laser point position corresponding coverage area is ensured, and the planning of the point position coverage area is unreasonable, which leads to the decline of the gas leakage detection efficiency of the corresponding sub-region, cannot timely carry out leakage early warning, and when the laser detection is inefficient and there is no leakage risk, it is easy to cause pipe network control decision error, greatly reducing the safety of the gas conveying of the oil and gas well pipe network.

[0062] The leakage detection analysis unit receives the leakage detection analysis signal, and the leakage type of the current sub-region pipe network is inferred through the leakage gas detection, so that the leakage fault reason of the sub-region pipe network is inferred through the leakage type, so that the fault type can be determined while detecting the gas leakage, the pipe network regulation and control can be carried out in time, the influence of the gas leakage of the sub-region pipe network is reduced, and the gas conveying risk of the sub-region pipe network can be effectively detected through the leakage detection analysis, providing data reference for timely risk avoidance.

[0063] The laser detection error analysis unit analyzes the error of the laser detection process, infers whether the laser detection error of each sub-region is high-risk, and thus timely error regulation and control are carried out to reduce the leakage detection error rate of the sub-region, so that timely leakage control can be carried out, the leakage influence cannot be reduced to the minimum, and there are still safety hazards for different gas types, greatly reducing the safety and stability of the pipe network gas conveying. BRIEF DESCRIPTION OF DRAWINGS

[0064] ATTACHMENT Figure 1 The oil and gas well gas leakage detection and early warning system structure schematic diagram provided by the present application.

[0065] ATTACHMENT Figure 2 The laser detection adaptive adjustment unit structure schematic diagram provided by the present application.

[0066] ATTACHMENT Figure 3 The laser point position coverage analysis unit structure schematic diagram provided by the present application.

[0067] ATTACHMENT Figure 4 The leakage detection analysis unit structure schematic diagram provided by the present application.

[0068] Figure 1 is a structural schematic diagram of a laser detection error analysis unit provided by the present application. Figure 5 Figure 2 is a structural schematic diagram of a laser detection error analysis unit provided by the present application.

[0069] Figure 3 is a structural schematic diagram of a laser detection error analysis unit provided by the present application. Figure 6 Figure 4 is a flowchart of an oil and gas well gas leakage detection and early warning method provided by the present application. DETAILED DESCRIPTION

[0070] The present application is not limited by the following examples, and the specific implementation can be determined according to the technical solutions of the present application and the actual situation.

[0071] Those skilled in the art can understand that, unless specifically stated, the "module" or "unit" in the embodiments of the present application refers to a computer program or a part of a computer program with a predetermined function, and works together with other related parts to achieve a predetermined target, and can be implemented entirely or partially by using software, hardware (such as a processing circuit or a memory) or a combination thereof. Similarly, one processor (or multiple processors or memories) can be used to implement one or more modules or units. In addition, each module or unit can be a part of an overall module or unit that includes the functions of the module or unit.

[0072] In addition, "multiple" in the embodiments of the present application refers to two or more, and "first" and "second" and the like are used for differentiation and description, and cannot be understood as implying relative importance.

[0073] As shown in Figure 1, the oil and gas well gas leakage detection and early warning system based on laser detection includes a laser detection platform, a laser point position coverage analysis unit and a leakage detection analysis unit are arranged in the laser detection platform, the laser detection platform is used to set the laser point position coverage, and performs leakage detection analysis after detecting the gas leakage of the oil and gas well pipe network based on the laser point position coverage, and the laser detection platform is connected with a laser detection adaptive adjustment unit and a laser detection error analysis unit, wherein the laser detection adaptive adjustment unit and the laser detection error analysis unit are used for assisting before and after the operation of the laser detection platform. Figure 1 Specifically, the technical solutions of the present application will be introduced and described below in combination with several examples.

[0074] Embodiment 1: As shown in Figure 1, the embodiments of the present application disclose an oil and gas well gas leakage detection and early warning system based on laser detection, which includes a laser detection platform, the laser detection platform is connected with a laser detection adaptive adjustment unit and a laser detection error analysis unit, and the laser detection platform includes a laser point position coverage analysis unit and a leakage detection analysis unit.

[0075] Figure 1 Embodiment 1: As shown in Figure 1, the embodiments of the present application disclose an oil and gas well gas leakage detection and early warning system based on laser detection, which includes a laser detection platform, the laser detection platform is connected with a laser detection adaptive adjustment unit and a laser detection error analysis unit, and the laser detection platform includes a laser point position coverage analysis unit and a leakage detection analysis unit.

[0076] ​The laser detection adaptive adjustment unit divides the oil and gas well pipe network into a plurality of sub-regions, determines the detection type and the laser type according to the cumulative type of the gas transported by the pipe network in each sub-region, sets the real-time laser type of each sub-region by threshold comparison through the corresponding laser control information and laser irradiation information;

[0077] The laser point position coverage analysis unit, in combination with the real-time laser type of each sub-region, uses a point position setting rule to mark the point position setting information of the preset point position, obtains the corresponding point position setting coefficient, and determines the laser point position of each sub-region according to the comparison result of the point position setting coefficient and the point position setting coefficient threshold, wherein the point position setting coefficient is as follows:

[0078]

[0079] Wherein, h1, h2, h3 are preset proportion coefficients; β is an error correction factor; YC, PLK, XZ are point position setting information;

[0080] The leakage detection analysis unit obtains and determines the pipe network leakage type of each sub-region according to the leakage detection analysis signal after laser detection, and generates and sends an early warning signal, wherein the leakage detection analysis signal includes leakage concentration difference data and leakage transportation influence data.

[0081] The laser detection error analysis unit compares the concentration error information and the wavelength error information of each sub-region with the maximum sensitivity deviation threshold and the wavelength increase span threshold respectively, and obtains the laser detection error risk of each sub-region.

[0082] Embodiment 2: as shown in the accompanying Figure 2 The laser detection adaptive adjustment unit comprises:

[0083] The type determination module divides the oil and gas well pipe network into a plurality of sub-regions, counts the cumulative gas type transported by the pipe network in each sub-region, marks it as a detection type, and obtains the laser type according to the existing laser emitter, and obtains the laser type that reacts with the detection type;

[0084] It should be noted that when the laser emitter emits a laser of a certain type and irradiates it to the leaked gas type, the laser and the leaked gas molecules interact when the gas receives the laser irradiation, and scattering and absorption phenomena occur, so that the returned laser signal characteristics change compared to the original laser type, that is, the gas has laser reaction.

[0085] The information acquisition module acquires the laser control information and the laser irradiation information corresponding to the detection type and the laser type of each sub-region;

[0086] The laser control information is a numerical ratio between a wavelength adjustment span of a laser type and a cost generated by actual laser adjustment.

[0087] Here, the numerical ratio is represented as a ratio of corresponding numerical values of two data, without considering the units of the two data, and only the numerical floating of the two data is counted.

[0088] The laser irradiation information is a delay time corresponding to an alternative conversion of different laser types in a reciprocating floating process of the required detection type.

[0089] The real-time laser type setting module compares the laser control information and the laser irradiation information of each sub-region with a numerical ratio threshold and a delay time threshold, respectively, according to a preset real-time laser type analysis rule, and sets the real-time laser type of each sub-region.

[0090] The real-time laser type analysis rule includes:

[0091] (1) If the laser control information does not exceed the numerical ratio threshold, or the laser irradiation information exceeds the delay time threshold, it is inferred that the required detection type of the gas transported by the current sub-region cannot completely adapt to laser detection, a laser detection risk signal is generated and sent to the laser detection platform, and the laser detection platform receives the laser detection risk signal and analyzes the gas type transported by the current sub-region. The gas delivery amount and delivery frequency of the corresponding type are compared, and if either the gas delivery amount or the delivery frequency exceeds the set threshold, the corresponding gas type is detected by laser, and the adaptive laser type of the corresponding type is set as the emission laser type of the laser emitter. The number of laser types is not unique, and when the laser type is converted, the type is covered without delay, otherwise it is excluded, and the type excluded when the gas delivery amount is small is monitored by the corresponding type gas sensor.

[0092] (2) If the laser control information exceeds the numerical ratio threshold, and the laser irradiation information exceeds the delay time threshold, it is inferred that the required detection type of the gas transported by the current sub-region completely adapts to laser detection, and the laser type corresponding to the gas transported by the current sub-region is set as the real-time setting type.

[0093] In the embodiment, the laser detection adaptation adjustment unit matches the laser type and the required detection type of the oil and gas well pipe network, and through reasonable matching, it can ensure that the pipelines of each sub-region of the oil and gas well pipe network can accurately detect different types of gas when transporting gas, to ensure the effectiveness of the oil and gas well pipe network leakage detection, ensure the timeliness of the oil and gas well pipe network leakage detection, improve the feasibility of the oil and gas well pipe network laser detection, avoid the inadaptation of the laser type to the current leakage gas, cause the detection data to deviate, and affect the gas delivery efficiency of the oil and gas well pipe network.

[0094] Embodiment 3: as shown in the accompanyingFigure 3 As shown, the embodiment of the present application is a further optimization of the above embodiment, wherein the laser point coverage analysis unit comprises:

[0095] The preset point marking module matches the corresponding laser emitter according to the required detection type of each sub-region and the real-time laser type, marks the preset point of each sub-region based on the coverage area of the laser emitter and the preset point marking rule, wherein the preset point marking rule is to overlap the coverage area of the laser emitter with the area of the current corresponding sub-region, and mark the corresponding point as the preset point when the overlapping area is at the peak.

[0096] The point setting information marking module marks the point setting information of the preset point of each sub-region by using the point setting rule;

[0097] The point setting rule comprises:

[0098] (1) Obtain the reciprocal delay time length increase frequency of the corresponding laser emission period in different regional environments when the preset point in the sub-region emits laser to any position in the sub-region, and mark it as YC;

[0099] Wherein, the regional environment is represented by environmental temperature, humidity, etc.; the emission period is represented by the period constructed by the two actions of laser emission and recovery;

[0100] (2) Obtain the frequency span ratio between the maintenance frequency increase span of the corresponding laser emitter and the leakage gas detection frequency increase span in the sub-region where the laser emitter is put, and mark it as PLK;

[0101] (3) Obtain the time proportion of the laser emission device debugging time span corresponding to the change of the gas type in the sub-region and the time span after the change of the gas type, and mark it as XZ;

[0102] The point setting coefficient calculation module brings the point setting information of the preset point of each sub-region into the point setting coefficient calculation formula to obtain the corresponding point setting coefficient:

[0103]

[0104] Wherein, h1, h2, h3 are preset proportion coefficients; YC, PLK, XZ are point setting information; β is an error correction factor, which can be 0.97 in this embodiment.

[0105] The laser point determination module compares the point setting coefficient corresponding to the preset point of each sub-region with the point setting coefficient threshold, and obtains the laser point of each sub-region in combination with the laser point determination rule;

[0106] The laser point determination rule comprises:

[0107] (1) If the point setting coefficient of the preset point exceeds the point setting coefficient threshold, the preset point of the current sub-region cannot be set as a set point, the preset point of the sub-region is offset, and the offset point is set as a laser point;

[0108] Here, the offset size can be obtained by summarizing historical data or set according to actual needs;

[0109] (2) If the point setting coefficient of the preset point does not exceed the point setting coefficient threshold, the preset point of the current sub-region is set as a set point, and the preset point of the sub-region is set as a laser point;

[0110] The laser point coverage analysis unit of the embodiment plans the laser point coverage area of the sub-region, and plans the laser point coverage area reasonably to ensure the detection accuracy of the corresponding coverage area of the laser point, avoids unreasonable planning of the point coverage area, causes the gas leakage detection efficiency of the corresponding sub-region to decrease, cannot timely perform leakage early warning, and easily causes pipe network control decision error when the laser detection is inefficient and there is no leakage risk, greatly reduces the safety of oil and gas well pipe network gas transportation.

[0111] Embodiment 4: As shown in the accompanying Figure 4 Embodiment, the embodiment of the application is further optimized on the basis of the above-mentioned embodiments, wherein the leakage detection analysis unit comprises:

[0112] A leakage detection analysis signal acquisition module acquires leakage detection analysis signals of each sub-region, wherein the leakage detection analysis signals comprise leakage concentration difference data and leakage transportation influence data, the leakage concentration difference data is a floating span of a concentration difference of a corresponding type of gas inside and outside a pipeline before and after a detection leakage moment of a pipe network leakage position in a sub-region, and the leakage transportation influence data is a sum of a corresponding span of a pipeline gas transportation pressure reduction span and a pipeline external gas concentration rise span after the appearance of the pipe network leakage position.

[0113] A leakage type determination module compares the leakage detection analysis signals of each sub-region with a concentration difference floating span threshold and a pressure concentration span threshold respectively, determines a pipe network leakage type of each sub-region in combination with a pipe network leakage type judgment rule, generates and sends a maintenance early warning signal;

[0114] It should be noted that the span sum is only a numerical addition of the span of two data, inferring the influence of the numerical floating, without considering the problem of non-uniform units.

[0115] The pipe network leakage type judgment rule comprises:

[0116] (1) If the floating span of the concentration difference of the corresponding type of gas inside and outside the pipeline before and after the detection leakage moment of the leakage position of the pipeline network in the sub-region exceeds the concentration difference floating span threshold, and the sum of the corresponding spans of the pressure drop span of the gas in the pipeline at the corresponding position after the occurrence of the leakage position of the pipeline network and the concentration rise span of the gas outside the pipeline exceeds the pressure concentration span sum threshold, then the pipeline leakage type of the sub-region is instantaneous leakage and high leakage impact, a rupture warning signal is generated and sent;

[0117] Here, the content of the rupture warning signal can be but is not limited to that a rupture occurs at a certain point of the pipeline.

[0118] (2) If the floating span of the concentration difference of the corresponding type of gas inside and outside the pipeline before and after the detection leakage moment of the leakage position of the pipeline network in the sub-region does not exceed the concentration difference floating span threshold, and the sum of the corresponding spans of the pressure drop span of the gas in the pipeline at the corresponding position after the occurrence of the leakage position of the pipeline network and the concentration rise span of the gas outside the pipeline exceeds the pressure concentration span sum threshold, then the pipeline leakage type of the sub-region is continuous leakage and high leakage impact, a large-area warning signal is generated and sent;

[0119] Here, the content of the large-area warning signal can be but is not limited to that multiple small cracks continuously occur in a certain area of the pipeline.

[0120] (3) If the floating span of the concentration difference of the corresponding type of gas inside and outside the pipeline before and after the detection leakage moment of the leakage position of the pipeline network in the sub-region exceeds the concentration difference floating span threshold, and the sum of the corresponding spans of the pressure drop span of the gas in the pipeline at the corresponding position after the occurrence of the leakage position of the pipeline network and the concentration rise span of the gas outside the pipeline does not exceed the pressure concentration span sum threshold, then this type of situation does not exist, and the large concentration difference floating span will cause the concentration of the gas outside the pipeline to rise.

[0121] (4) If the floating span of the concentration difference of the corresponding type of gas inside and outside the pipeline before and after the detection leakage moment of the leakage position of the pipeline network in the sub-region does not exceed the concentration difference floating span threshold, and the sum of the corresponding spans of the pressure drop span of the gas in the pipeline at the corresponding position after the occurrence of the leakage position of the pipeline network and the concentration rise span of the gas outside the pipeline does not exceed the pressure concentration span sum threshold, then the pipeline leakage type of the sub-region is continuous leakage and low leakage impact, a maintenance warning signal is generated and sent;

[0122] Here, the content of the maintenance warning signal can be but is not limited to that a small number of small cracks occur.

[0123] It should be noted that when generating and sending various warning signals, the administrator terminal can be sent.

[0124] The embodiment is characterized in that after the laser point position is used to detect the leakage of the sub-area, the leakage detection analysis unit receives a leakage detection analysis signal, and the leakage type of the current sub-area pipe network is inferred through the leakage gas detection, so that the leakage fault reason of the sub-area pipe network is inferred through the leakage type, so that the fault type can be determined while the gas leakage is detected, the pipe network is regulated in time, the influence of the gas leakage of the sub-area pipe network is reduced, and the gas transmission risk of the sub-area pipe network can be effectively detected through the leakage detection analysis, so as to provide data reference for timely risk avoidance.

[0125] Embodiment 5: as shown in the accompanying drawings, the embodiment of the application is a further optimization of the above-mentioned embodiments, wherein the laser detection error analysis unit comprises: Figure 5

[0126] The error analysis data acquisition module acquires the concentration error information and the wavelength error information of each sub-area.

[0127] The concentration error information is the maximum deviation value of the laser detection sensitivity of the corresponding leakage gas type when the real-time leakage concentration span of the corresponding leakage gas type of the sub-area exceeds the set threshold value; and the wavelength error information is the wavelength increase span of the repeated part of the laser spectrum absorption when the gas type of the pipeline area corresponding to any laser detection leakage position of the sub-area pipe network is not a single type.

[0128] It should be noted that the detection sensitivity is represented as the concentration scale value that can be detected in real time by the laser detection when the corresponding concentration fluctuates after the gas leakage.

[0129] The error risk judgment module compares the concentration error information and the wavelength error information of each sub-area with the maximum deviation threshold value of the sensitivity and the wavelength increase span threshold value respectively, and obtains the laser detection error risk of each sub-area in combination with the error risk judgment rule.

[0130] The error risk judgment rule comprises:

[0131] (1) If the maximum deviation value of the laser detection sensitivity of the corresponding leakage gas type exceeds the maximum deviation threshold value of the sensitivity when the real-time leakage concentration span of the corresponding leakage gas type of the sub-area exceeds the set threshold value, or the wavelength increase span of the repeated part of the laser spectrum absorption exceeds the wavelength increase span threshold value when the gas type of the pipeline area corresponding to any laser detection leakage position of the sub-area pipe network is not a single type, then the laser detection error risk of the sub-area is high, and the pipeline position in the sub-area needs to be re-inspected.

[0132] ​(2) if the maximum deviation value of the laser detection sensitivity of the corresponding leakage gas type does not exceed the sensitivity maximum deviation threshold value when the real-time leakage concentration span of the corresponding leakage gas type of the sub-region exceeds the set threshold value, and the gas type of the pipeline region corresponding to the arbitrary laser detection leakage position of the sub-region is not a single type, and the wavelength increase span of the repeated part of the laser spectrum absorption does not exceed the wavelength increase span threshold value, then the laser detection error risk of the sub-region is low, and the laser detection of the sub-region is continued;

[0133] The laser detection error analysis unit of the embodiment analyzes the error of the laser detection process, infers whether the laser detection error of each sub-region is at high risk, and thus timely error control is performed to reduce the leakage detection error rate of the sub-region, so that timely leakage control can be performed, and the problem that the leakage influence cannot be reduced to the minimum and different gas types still have safety hazards is avoided, greatly reducing the safety and stability of the pipeline network gas delivery.

[0134] Embodiment 6: as shown in the accompanying Figure 6 The embodiment of the application discloses a kind of based on laser detection's oil and gas well gas leakage detection and early warning method, including

[0135] Step S110, the oil and gas well pipeline network is divided into several sub-regions using a laser detection adaptive adjustment unit, determines the type to be detected and the laser type according to the cumulative type of the gas transported by the pipeline network in each sub-region, and sets the real-time laser type of each sub-region by threshold comparison using the corresponding laser control information and laser irradiation information.

[0136] Step S120, using a laser point position coverage analysis unit in combination with the real-time laser type of each sub-region, using point position setting rule to mark the point position setting information of the preset point position, obtaining the corresponding point position setting coefficient, determining the laser point position of each sub-region according to the comparison result of the point position setting coefficient and the point position setting coefficient threshold value, wherein the point position setting coefficient is as follows:

[0137]

[0138] Wherein, h1, h2, h3 are preset proportion coefficients respectively; β is an error correction factor; YC, PLK, XZ are point position setting information respectively;

[0139] Step S130, using a leakage detection analysis unit to determine the pipeline network leakage type of each sub-region according to the leakage detection analysis signal, generating and sending an early warning signal, the leakage detection analysis signal includes leakage concentration difference data and leakage transport influence data.

[0140] In step S140, the concentration error information and the wavelength error information of each sub-region are compared with the maximum deviation threshold of sensitivity and the wavelength increase span threshold respectively by the laser detection error analysis unit to obtain the laser detection error risk of each sub-region.

[0141] The specific implementation steps of each step are the same as those of Embodiments 1 to 5, and will not be described again.

[0142] The above is only a specific embodiment of the present application, which has strong adaptability and implementation effect, but the protection scope of the present application is not limited thereto, any person skilled in the art can easily think of changes or replacements within the technical range disclosed by the present application, which should be covered within the protection scope of the present application, therefore, equivalent changes made according to the claims of the present application are still within the scope covered by the present application.

Claims

1. A laser detection based oil and gas well gas leakage detection and warning system, characterized in that, The laser detection platform is connected with a laser detection adaptive adjustment unit and a laser detection error analysis unit, and the laser detection platform includes a laser point position coverage analysis unit and a leakage detection analysis unit; The laser detection adaptive adjustment unit divides the oil and gas well pipe network into a plurality of sub-regions, determines the type to be detected and the laser type according to the cumulative type of the gas transported by the pipe network in each sub-region, and sets the real-time laser type of each sub-region by threshold comparison through the corresponding laser control information and laser irradiation information; The laser point position coverage analysis unit, in combination with the real-time laser type of each sub-region, uses a point position setting rule to mark the point position setting information of the preset point position, obtains the corresponding point position setting coefficient, and determines the laser point position of each sub-region according to the comparison result of the point position setting coefficient and the point position setting coefficient threshold, wherein the point position setting rule includes: obtaining the reciprocating delay time length increase frequency of the corresponding laser emission period under different regional environments when the preset point position in the sub-region emits laser to any position in the sub-region, marking it as YC, obtaining the frequency span between the corresponding laser emitter maintenance frequency increase span and the leakage gas detection frequency increase span of the sub-region transported by the laser emitter, marking it as PLK, and obtaining the time span between the corresponding matching laser emitter debugging time and the time span after the gas type is changed, marking it as XZ, wherein the point position setting coefficient is as follows: Wherein, h1, h2, h3 are preset proportion coefficients; β is an error correction factor; The leakage detection analysis unit obtains and determines the pipe network leakage type of each sub-region according to the leakage detection analysis signal after laser detection, and generates and sends an early warning signal, wherein the leakage detection analysis signal includes leakage concentration difference data and leakage transportation influence data; The laser detection error analysis unit compares the concentration error information and wavelength error information of each sub-region with the maximum sensitivity deviation threshold and the wavelength increase span threshold respectively to obtain the laser detection error risk of each sub-region.

2. The laser detection based oil and gas well gas leakage detection and warning system according to claim 1, characterized in that, The laser detection adaptive adjustment unit comprises: The type determination module divides the oil and gas well pipe network into a plurality of sub-regions, counts the cumulative gas type transported by the pipe network in each sub-region, marks it as the type to be detected, and obtains the laser type according to the existing laser emitter, and obtains the laser type that reacts with the type to be detected; The information acquisition module obtains the laser control information and laser irradiation information corresponding to the type to be detected and the laser type of each sub-region; The real-time laser type setting module compares the laser control information and laser irradiation information of each sub-region with the numerical value threshold and the delay time threshold respectively according to the preset real-time laser type analysis rule, and sets the real-time laser type of each sub-region.

3. The laser detection based oil and gas well gas leakage detection and warning system according to claim 2, characterized in that, The real-time laser type analysis rule includes: If the laser control information does not exceed the numerical ratio threshold, or the laser irradiation information exceeds the delay duration threshold, it is inferred that the type of gas to be detected in the current sub-region cannot fully adapt to laser detection, a laser detection risk signal is generated and sent to the laser detection platform, and the laser detection platform receives the laser detection risk signal. After receiving the laser detection risk signal, the type of gas delivered by the pipe network in the current sub-region is analyzed, and the delivery amount and delivery frequency of the corresponding type of gas are compared. If either the delivery amount or the delivery frequency exceeds the set threshold, the corresponding type of gas is detected by laser, and the corresponding adaptive laser type is set as the emission laser type of the laser emitter. The number of laser types is not unique, and there is no delay in laser type conversion. Type coverage is performed, otherwise, the type is excluded. When the delivery amount of the corresponding type of gas is small, the corresponding type of gas sensor is used for monitoring. If the laser control information exceeds the numerical ratio threshold, and the laser irradiation information exceeds the delay duration threshold, it is inferred that the type of gas to be detected in the current sub-region fully adapts to laser detection, and the laser type corresponding to the gas delivered by the current sub-region is set as the real-time setting type.

4. The laser detection based oil and gas well gas leak detection and pre-alarm system according to claim 1 or 2 or 3, characterized in that, The laser point position coverage analysis unit comprises: A preset point position marking module marks the preset point positions of each sub-region according to the matching of the type of gas to be detected and the real-time laser type of each sub-region, and based on the coverage area of the laser emitter and a preset point position marking rule. The preset point position marking rule is to overlap the coverage area of the laser emitter with the area of the current corresponding sub-region, and to mark the corresponding point position as a preset point position when the overlapping area is at a peak value. A point position setting information marking module marks the point position setting information of the preset point positions of each sub-region using a point position setting rule. A point position setting coefficient calculation module brings the point position setting information of the preset point positions of each sub-region into a point position setting coefficient calculation formula to obtain the corresponding point position setting coefficient. A laser point position determination module compares the point position setting coefficient of the preset point positions of each sub-region with a point position setting coefficient threshold, and obtains the laser point position of each sub-region in combination with a laser point position determination rule. The laser point position determination rule comprises: If the point position setting coefficient of the preset point position exceeds the point position setting coefficient threshold, the preset point position of the current sub-region cannot be used as a setting point position, and the preset point position of the sub-region is offset and the offset point position is set as the laser point position. If the point position setting coefficient of the preset point position does not exceed the point position setting coefficient threshold, the preset point position of the current sub-region is used as a setting point position, and the preset point position of the sub-region is set as the laser point position.

5. The laser detection based oil and gas well gas leak detection and pre-alarm system according to claim 1 or 2 or 3, characterized in that, The leakage detection analysis unit comprises: A leakage detection analysis signal acquisition module acquires leakage detection analysis signals of each sub-region. The leakage detection analysis signals comprise leakage concentration difference data and leakage delivery influence data. The leakage concentration difference data is the floating span of the concentration difference of the corresponding type of gas inside and outside the pipeline before and after the detection leakage moment of the leakage position of the pipe network in the sub-region. The leakage delivery influence data is the sum of the corresponding span of the pipeline gas delivery pressure reduction span and the pipeline external gas concentration rise span after the appearance of the pipe network leakage position. The leakage type determination module compares the leakage detection analysis signals of each sub-region with a concentration difference floating span threshold and a pressure concentration span threshold respectively, and determines the pipeline network leakage type of each sub-region according to a pipeline network leakage type judgment rule, and generates and sends a maintenance warning signal.

6. The laser detection based oil and gas well gas leak detection and warning system of claim 5, wherein, The pipeline network leakage type judgment rule comprises: if the floating span of the concentration difference of the corresponding type of gas before and after the detection leakage moment of the pipeline network leakage position in the sub-region exceeds the concentration difference floating span threshold, and the sum of the corresponding spans of the gas delivery pressure reduction span of the pipeline at the corresponding position after the appearance of the pipeline network leakage position and the gas concentration rise span outside the pipeline exceeds the pressure concentration span sum threshold, then the pipeline leakage type of the sub-region is instantaneous leakage with high leakage influence, and a rupture warning signal is generated and sent; if the floating span of the concentration difference of the corresponding type of gas before and after the detection leakage moment of the pipeline network leakage position in the sub-region does not exceed the concentration difference floating span threshold, and the sum of the corresponding spans of the gas delivery pressure reduction span of the pipeline at the corresponding position after the appearance of the pipeline network leakage position and the gas concentration rise span outside the pipeline exceeds the pressure concentration span sum threshold, then the pipeline leakage type of the sub-region is continuous leakage with high leakage influence, and a large-scale warning signal is generated and sent; if the floating span of the concentration difference of the corresponding type of gas before and after the detection leakage moment of the pipeline network leakage position in the sub-region exceeds the concentration difference floating span threshold, and the sum of the corresponding spans of the gas delivery pressure reduction span of the pipeline at the corresponding position after the appearance of the pipeline network leakage position and the gas concentration rise span outside the pipeline does not exceed the pressure concentration span sum threshold, then this type of situation does not exist, and a large concentration difference floating span will cause the gas concentration outside the pipeline to rise; if the floating span of the concentration difference of the corresponding type of gas before and after the detection leakage moment of the pipeline network leakage position in the sub-region does not exceed the concentration difference floating span threshold, and the sum of the corresponding spans of the gas delivery pressure reduction span of the pipeline at the corresponding position after the appearance of the pipeline network leakage position and the gas concentration rise span outside the pipeline does not exceed the pressure concentration span sum threshold, then the pipeline leakage type of the sub-region is continuous leakage with low leakage influence, and a maintenance warning signal is generated and sent.

7. The laser detection based oil and gas well gas leak detection and pre-alarm system according to claim 1 or 2 or 3, characterized in that, The laser detection error analysis unit comprises: The error analysis data acquisition module acquires concentration error information and wavelength error information of each sub-region, wherein the concentration error information is the maximum deviation value of the laser detection sensitivity of the corresponding leakage gas type when the real-time leakage concentration span of the corresponding leakage gas type in the sub-region exceeds the set threshold; and the wavelength error information is the wavelength increase span of the repeated part of the laser spectrum absorption when the gas type of the pipeline region corresponding to any laser detection leakage position of the sub-region pipeline network is not single type; The error risk judgment module compares the concentration error information and the wavelength error information of each sub-region with a sensitivity maximum deviation threshold and a wavelength increase span threshold respectively, and obtains the laser detection error risk of each sub-region according to an error risk judgment rule.

8. The laser detection based oil and gas well gas leak detection and warning system of claim 7, wherein, The error risk judgment rule comprises: If the maximum deviation value of the laser detection sensitivity of the corresponding leakage gas type exceeds the sensitivity maximum deviation threshold value when the real-time leakage concentration span of the corresponding leakage gas type of the sub-region exceeds the set threshold value, or the wavelength increase span of the repeated part of the laser spectral absorption exceeds the wavelength increase span threshold value when the gas type of the pipeline region corresponding to any laser detection leakage position of the sub-region pipeline network is not a single type, the laser detection error risk of the sub-region is high, and the pipeline positions in the sub-region need to be re-inspected; If the maximum deviation value of the laser detection sensitivity of the corresponding leakage gas type does not exceed the sensitivity maximum deviation threshold value when the real-time leakage concentration span of the corresponding leakage gas type of the sub-region exceeds the set threshold value, and the wavelength increase span of the repeated part of the laser spectral absorption does not exceed the wavelength increase span threshold value when the gas type of the pipeline region corresponding to any laser detection leakage position of the sub-region pipeline network is not a single type, the laser detection error risk of the sub-region is low, and the laser detection of the sub-region continues.

9. A method for detecting and warning gas leakage of an oil and gas well applied to the system according to any one of claims 1 to 8, characterized in that, Comprising The oil and gas well pipeline network is divided into several sub-regions by using a laser detection adaptive adjustment unit, the cumulative type of the gas transported by the pipeline network in each sub-region is determined to determine the type to be detected and the laser type, and the real-time laser type of each sub-region is set by comparing the threshold values using the corresponding laser control information and laser irradiation information; The laser point position coverage analysis unit is used to determine the laser point position of each sub-region by combining the real-time laser type of each sub-region, using point position setting information to mark the preset point position according to the point position setting rule, and obtaining the corresponding point position setting coefficient according to the comparison result of the point position setting coefficient and the point position setting coefficient threshold value, wherein the point position setting coefficient is as follows: Wherein, h1, h2, h3 are preset proportion coefficients; β is an error correction factor; YC, PLK, XZ are point position setting information; The leakage detection analysis unit is used to determine the pipeline leakage type of each sub-region according to the leakage detection analysis signal, generate and send a warning signal, and the leakage detection analysis signal includes leakage concentration difference data and leakage transportation influence data; The laser detection error analysis unit is used to compare the concentration error information and the wavelength error information of each sub-region with the sensitivity maximum deviation threshold value and the wavelength increase span threshold value respectively, and obtain the laser detection error risk of each sub-region.

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