Method and device for detecting water content of petroleum

Abstract

The invention discloses a method and a device for detecting the water content of petroleum. The device comprises an infrared light source for emitting infrared light and an infrared light detector for detecting the infrared light, the three infrared light detectors are respectively a first measurement infrared light detector, an interference judgment infrared light detector and a second measurement infrared light detector; a detection flow channel for flowing of to-be-detected petroleum is arranged between the infrared light source and the detectors, so that infrared light emitted by the infrared light detectors is detected by the three infrared light detectors after penetrating through the to-be-detected petroleum; the device further comprises a data processing module, and the data processing module is used for judging the interference type according to the interference judgment infrared light detector and calculating the water content of the to-be-detected petroleum flowing through the detection flow channel by utilizing the infrared light intensity detected by the first measurement infrared light detector and the second measurement infrared light detector. The device can eliminate the interference of gravel and bubbles on the water content detection, and can accurately detect the water content in petroleum.

Description

Technical Field

[0001] The present invention belongs to the technical field of petroleum water content detection, and in particular relates to a method and device for detecting petroleum water content. Background Art

[0002] Crude oil, as an important strategic energy source and chemical raw material, requires precise measurement of its composition, especially its water content, which is crucial for oil well assessment, production management, and resource utilization. Real-time monitoring of the water content of crude oil in pipelines during extraction, transportation, and processing is crucial for optimizing extraction plans, controlling production processes, and evaluating economic benefits. However, crude oil is a complex mixture of hydrocarbons, water, bubbles, sand, and gravel, and is often exposed to high-velocity, multiphase flow in a dynamic environment, making its water content detection challenging.

[0003] Currently, real-time detection technologies for crude oil water content mainly include capacitance method, radio frequency method, high-frequency electromagnetic eddy current method, ultrasonic detection method, gamma ray method and microwave method. These methods are based on different physical principles and have their own characteristics, but they all have significant limitations in practical applications:

[0004] The capacitance method reflects the water content by measuring the change in the dielectric constant between the two plates. However, the edge effect of the plates can introduce measurement errors, especially in high water content scenarios where the error can reach more than 3%. It is also easily affected by impurities in the crude oil (such as sand, gravel, and bubbles), resulting in insufficient stability.

[0005] The gamma ray method uses the attenuation characteristics of gamma rays when passing through crude oil to detect water content. It requires a radiation source and a high-precision detector. Not only does it pose a radiation safety risk, but the system structure is complex and costly. At the same time, the water content measurement range is narrow (usually less than 80%), making it difficult to meet full-scale detection requirements.

[0006] The microwave method is based on the reflection or attenuation characteristics of microwaves in different media to achieve detection, but its instrument design is complex and requires extremely high instant response from the sensor. In high flow rate or multiphase flow environment, the detection efficiency drops significantly, and the signal is easily disturbed by fluctuations in crude oil components.

[0007] Other methods such as radio frequency and ultrasonic methods, although they have certain real-time properties, are limited by the detection principles and have deficiencies in water content range, anti-interference ability and long-term stability, making it difficult to adapt to the high-precision detection needs under complex working conditions.

[0008] Chinese patent application CN202011441384.2 discloses a method and system for detecting water content, which obtains detection information of all detection points of water content identification data in target real-time water content detection data, wherein the detection information includes area, water content and total volume, and divides and processes all detection points of the water content identification data according to the detection information to obtain divided detection points of the water content identification data, and determines the water content percentage according to the divided detection points of the water content identification data in the target real-time water content detection data.

[0009] The above-mentioned existing technologies rely on regional division and statistical methods, which have certain limitations in detection accuracy and reliability. In addition, the existing technologies are easily disturbed in complex multiphase flow environments, resulting in large detection errors. Summary of the Invention

[0010] The purpose of the present invention is to provide a method and device for detecting water content in petroleum, which can partially solve or alleviate the above-mentioned shortcomings in the prior art, eliminate the interference of sand and bubbles on water content detection, and accurately detect the water content in petroleum.

[0011] In order to solve the above-mentioned technical problems, the present invention specifically adopts the following technical solutions:

[0012] A first aspect of the present invention is to provide a device for detecting the water content in petroleum, comprising an infrared light source for emitting infrared light and an infrared light detector for detecting infrared light; the device comprises three infrared light detectors, namely a first measuring infrared light detector having a response range of band I, an interference determination infrared light detector having a response range of band II, and a second measuring infrared light detector having a response range of band III; a detection flow channel for the flow of the petroleum to be detected is provided between the infrared light source and the detectors, so that the infrared light emitted by the infrared light detector is detected by the three infrared light detectors after passing through the petroleum to be detected; the device also comprises a data processing module, the data processing module being used to determine the type of interference based on the infrared light intensity detected by the interference determination infrared light detector, and to calculate the water content of the petroleum to be detected flowing through the detection flow channel using the infrared light intensity detected by the first measuring infrared light detector and the second measuring infrared light detector.

[0013] Furthermore, the band I is within the range of 900-1250 nm, the band II is within the range of 1251-1350 nm, and the band III is within the range of 1351-1700 nm.

[0014] Furthermore, three infrared light detectors are arranged side by side, and their arrangement direction is perpendicular to the flow direction of the oil to be detected; the infrared light source is opposite to the three infrared light detectors, and two quartz windows are used to isolate the infrared light source from the three infrared light detectors respectively; the interval between the two quartz windows is the detection flow channel.

[0015] Furthermore, the infrared light source is located directly above the three infrared light detectors, and the interval between the two quartz windows is the height of the detection flow channel; the height of the detection flow channel is not greater than 50 cm.

[0016] Furthermore, the infrared light detector is a short-wave infrared photoelectric detector integrated with a narrow-band filter.

[0017] The present invention also provides a method for detecting water content in petroleum, which is applied to the above-mentioned device for detecting water content in petroleum, comprising:

[0018] Relationship models I and II are constructed respectively between the light signals detected by the first infrared light detector and the second infrared light detector and the water content of the oil;

[0019] The infrared light emitted by the infrared light source illuminates the oil to be detected, and three infrared light detectors are used to collect the transmitted light signals respectively;

[0020] Interference judgment infrared light detector detected light signal The theoretical optical signal in a non-interference scenario For comparison, if the determination coefficient >1, it is determined that the oil to be detected has sand and gravel interference; if the determination coefficient <1, it is determined that the oil to be detected has bubble interference;

[0021] Substitute the decision relation k into relation model I and relation model II to obtain the water content of the oil to be tested.

[0022] Furthermore, the relationship model I is:

[0023] ;

[0024] The relationship model II is:

[0025] ;

[0026] Wherein, I1 is the intensity of the light signal detected by the first infrared light detector, I3 is the intensity of the light signal detected by the second infrared light detector, d is the height of the detection channel, a1 is the optical absorption coefficient of water-free petroleum to infrared light in band I, a3 is the optical absorption coefficient of water-free petroleum to infrared light in band III, b1 is the optical absorption coefficient of water to infrared light in band I, b3 is the optical absorption coefficient of water to infrared light in band III, and w is the volume percentage of water in the petroleum to be detected. To detect the presence of air in the flow channel, first measure the intensity of the light signal detected by the infrared light detector. The second measurement is to measure the intensity of the light signal detected by the infrared light detector when there is air in the flow channel.

[0027] Furthermore, the interference determination infrared light detector detects consistent light signal intensity for petroleum with any water content in a non-interference scenario.

[0028] Furthermore, when the oil to be detected has sand and gravel interference, the determination coefficient k is substituted into the relationship model I and the relationship model II, specifically:

[0029] ;

[0030] ;

[0031] in, The intensity of the light signal detected by the infrared light detector is first measured under the interference of sand and gravel. is the light signal intensity detected by the second infrared light detector under the interference of sand and gravel, k is the determination coefficient, d is the height of the detection flow channel, a1 is the optical absorption coefficient of oil without water to infrared light in band I, a3 is the optical absorption coefficient of oil without water to infrared light in band III, b1 is the optical absorption coefficient of water to infrared light in band I, b3 is the optical absorption coefficient of water to infrared light in band III, w is the volume percentage of water in the oil to be detected, To detect the presence of air in the flow channel, first measure the intensity of the light signal detected by the infrared light detector. To detect the intensity of the light signal detected by the second infrared light detector when there is air in the flow channel, For relational model I, For Relationship Model II;

[0032] By minimizing the error function:

[0033] ;

[0034] Solve the water content in the oil to be tested; where N is the relationship model number, is the relational model numbered N, k is the determination coefficient, is the optical signal strength of the relational model numbered N, is the adjustable accuracy threshold I.

[0035] Furthermore, when the oil to be detected has bubble interference, the formula

[0036] ;

[0037] Correct the detection channel height; where d2 is the corrected detection channel height, d is the detection channel height, k is the determination coefficient, and G is a constant related to the oil and water absorption coefficients;

[0038] Substitute the corrected detection flow channel height d2 and determination coefficient k into relationship model I and relationship model II, specifically:

[0039] ;

[0040] ;

[0041] in, The intensity of the light signal detected by the infrared light detector is first measured under the interference of sand and gravel. is the light signal intensity detected by the second infrared light detector under the interference of sand and gravel, k is the determination coefficient, d2 is the height of the corrected detection flow channel, a1 is the optical absorption coefficient of oil without water to infrared light in band I, a3 is the optical absorption coefficient of oil without water to infrared light in band III, b1 is the optical absorption coefficient of water to infrared light in band I, b3 is the optical absorption coefficient of water to infrared light in band III, w is the volume percentage of water in the oil to be detected, To detect the presence of air in the flow channel, first measure the intensity of the light signal detected by the infrared light detector. To detect the intensity of the light signal detected by the second infrared light detector when there is air in the flow channel, For relational model I, For Relationship Model II;

[0042] By minimizing the error function:

[0043] ;

[0044] Solve the water content in the oil to be tested; where N is the relationship model number, is the relational model numbered N, k is the determination coefficient, is the optical signal strength of the relational model numbered N, is the adjustable accuracy threshold II.

[0045] Beneficial effects:

[0046] The present invention uses three infrared light detectors with different response bands. The first measurement infrared light detector (Band I) and the second measurement infrared light detector (Band III) capture the absorption characteristics of crude oil and water from different spectral angles, constructing dual relationship models to verify each other; the interference judgment infrared light detector (Band II) focuses on identifying interference, avoiding the limitations of single-band detection, and greatly improving the accuracy and reliability of water content detection.

[0047] Leveraging the Band II detector's sensitivity to sand and bubble interference, the determination coefficient k accurately distinguishes interference types. For sand and stone interference, the signal strength is directly corrected; for bubble interference, the detection channel height is dynamically adjusted, and the water content is calculated by minimizing the error function. This effectively compensates for interference effects and ensures the stability and accuracy of test results under complex working conditions.

[0048] Three infrared detectors are positioned side by side, perpendicular to the oil flow direction. Combined with the infrared light source's perpendicular beam pattern, this ensures simultaneous detection of oil products within the same cross-section, minimizing errors caused by uneven flow. The detection channel height is limited to 8-12 cm, balancing light penetration depth and signal strength to accommodate varying water content and oil characteristics.

[0049] The infrared light detector integrates a narrowband filter that only allows light in the target band to pass through, effectively eliminating interference from other spectra, enhancing signal specificity and sensitivity, improving the detector signal-to-noise ratio, and reducing the impact of background noise on detection results.

[0050] The data processing module accurately calculates moisture content by building a precise model of the relationship between optical signals and moisture content, combining interference correction algorithms with a minimization error function. Adjustable precision thresholds can be flexibly adjusted based on actual needs, improving computational efficiency while maintaining detection accuracy. BRIEF DESCRIPTION OF THE DRAWINGS

[0051] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following is a brief introduction to the drawings required for the embodiments or the description of the prior art. In all drawings, similar elements or parts are generally identified by similar reference numerals. In the drawings, the various elements or parts are not necessarily drawn according to the actual scale. Obviously, the drawings described below are some embodiments of the present invention. For those of ordinary skill in the art, other drawings can also be obtained based on these drawings without inventive work.

[0052] Figure 1 This is a schematic structural diagram of Embodiment 1 of the present invention;

[0053] Figure 2 Schematic diagram of the structure of the infrared light detector;

[0054] Figure 3 This is a flow chart of embodiment 2 of the present invention.

[0055] Summary of reference numerals:

[0056] 1-infrared light source, 2-interference judgment infrared light detector, 3-first measurement infrared light detector, 4-second measurement infrared light detector, 5-quartz window, 11-short-wave infrared photodetector, 12-narrowband filter. DETAILED DESCRIPTION

[0057] To make the purpose, technical solutions, and advantages of the embodiments of the present invention more clear, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0058] Herein, suffixes such as "module," "component," or "unit" used to represent elements are only used to facilitate description of the present invention and have no specific meaning. Therefore, "module," "component," or "unit" may be used interchangeably.

[0059] As used herein, terms such as "upper," "lower," "inner," "outer," "front," "back," "one end," and "the other end" indicate positions or locations based on those shown in the accompanying drawings. These terms are intended solely to facilitate and simplify the description of the present invention and are not intended to indicate or imply that the devices or components referred to must have, be constructed, or operate in a specific orientation. Therefore, they should not be construed as limitations on the present invention. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0060] As used herein, unless otherwise expressly specified or limited, the terms "installed," "provided with," and "connected" should be understood broadly. For example, "connected" may refer to a fixed connection, a detachable connection, or an integral connection; it may refer to a mechanical connection, a direct connection, an indirect connection via an intermediate medium, or internal communication between two components. Those skilled in the art will understand the specific meanings of the above terms in the present invention on a case-by-case basis.

[0061] As used herein, "and / or" includes any and all combinations of one or more of the associated listed items.

[0062] Herein, "plurality" means two or more than two, ie, it includes two, three, four, five, etc.

[0063] Example 1:

[0064] like Figure 1 As shown, this embodiment provides a device for detecting water content in petroleum, including an infrared light source 1 for emitting infrared light and an infrared light detector for detecting infrared light; the infrared light detectors are three, namely a first measuring infrared light detector 3 having a response range of band I, an interference determination infrared light detector 2 having a response range of band II, and a second measuring infrared light detector 4 having a response range of band III; a detection flow channel for the flow of the petroleum to be detected is provided between the infrared light source 1 and the detectors, so that the infrared light emitted by the infrared light detector is detected by the three infrared light detectors after passing through the petroleum to be detected; and the device also includes a data processing module, which is used to determine the type of interference based on the infrared light intensity detected by the interference determination infrared light detector 2, and calculate the water content of the petroleum to be detected flowing through the detection flow channel using the infrared light intensity detected by the first measuring infrared light detector 3 and the second measuring infrared light detector 4.

[0065] The infrared light source 1 in this embodiment is preferably a tungsten halogen lamp, which emits infrared light covering the 900-1700 nm band, ensuring that the characteristic spectra required by the three detectors are excited simultaneously.

[0066] In this embodiment, the first infrared detector 3 (with a response range of band I in the 900-1250nm range) is sensitive to hydrocarbons in crude oil and is used to establish a crude oil matrix absorption model. Water, on the other hand, has weak absorption in this band, primarily reflecting crude oil characteristics.

[0067] In this embodiment, the second infrared detector 4 (with a response range of Band III between 1351 and 1700 nm) covers the secondary absorption peak of water, enhancing the robustness of the model. This aids in verifying water content and, in conjunction with Band I, improves inversion accuracy.

[0068] In this embodiment, the interference determination infrared light detector 2 (with a response range of Band II: 1251-1350nm) detects consistent optical signal intensity for oil with any water content in this band in an interference-free scenario. This means that water and oil absorb infrared light in this band at nearly identical rates. Therefore, in this embodiment, the interference determination infrared light detector 2 is used to determine whether other factors are interfering with the oil being tested.

[0069] Specifically, the infrared light detector comprises a short-wave infrared photodetector 11 integrated with a narrow-band filter 12. The short-wave infrared photodetector 11, such as an InGaAs infrared detector or a quantum dot infrared detector, is integrated with the narrow-band filter 12 to form a short-wave infrared light detector with narrow-band filtering detection function.

[0070] Three infrared detectors are arranged side by side, perpendicular to the flow direction of the oil being tested. The infrared light source 1 faces the three infrared detectors, each separated by two quartz windows 5. The space between the two quartz windows 5 forms the detection channel. More specifically, the infrared light source 1 is located directly above the three infrared detectors, and the space between the two quartz windows 5 is the height of the detection channel.

[0071] The three infrared detectors are arranged side by side, perpendicular to the flow direction of the oil being tested, ensuring they can simultaneously detect the same cross-section of the oil. As oil flows through a pipeline, its composition may be unevenly distributed. Placing the detectors perpendicular to the flow direction avoids errors caused by asynchronous detection positions. If the detectors are not arranged perpendicular to the flow direction, the composition of the oil detected first and later may differ, making it impossible to accurately reflect the actual water content of the oil at a given moment. This ensures that the test data truly reflects the current water content of the oil.

[0072] Furthermore, if the oil flow is separated by oil-water stratification, the vertical arrangement of the infrared light source 1 and infrared light detector can reduce measurement deviations caused by uneven layer thickness. Furthermore, vertical illumination ensures consistent optical path length, avoiding variations in light intensity caused by optical path length differences. This ensures that variations in the optical signal received by the detector are primarily determined by the water content of the oil, improving detection accuracy.

[0073] Two quartz windows 5 isolate the infrared light source 1 from the detector. This protects the light source and detector from oil contamination and corrosion, extending the device's service life. Furthermore, the quartz windows 5 offer excellent infrared transmittance, ensuring smooth passage of infrared light and minimizing light loss. Furthermore, the smooth and flat surface of the quartz windows 5 ensures a stable light propagation path, preventing light scattering or refraction caused by uneven window surfaces from interfering with detection results.

[0074] The detection channel in this embodiment is no taller than 50 cm, for example, 10 cm. From the perspective of light-matter interaction, the intensity of light propagating through oil varies with the propagation distance (i.e., the detection channel height) and the content of light-absorbing substances in the oil. If the detection channel is too short, the interaction between light and the water content in the oil will be insufficient, resulting in insignificant changes in the optical signal received by the detector and making it difficult to accurately detect the water content. If the detection channel is too long, light will attenuate excessively during propagation, resulting in a weak optical signal received by the detector and a reduced signal-to-noise ratio, which will also affect detection accuracy.

[0075] like Figure 2 As shown, a narrowband filter 12 is integrated on the infrared light detector in this embodiment.

[0076] The core function of the narrowband filter 12 is to filter optical signals within a specific wavelength range, allowing only infrared light within the response band to pass through while blocking light from other bands. In this embodiment, the first measuring infrared light detector 3 responds to Band I (within the 900-1250nm range). Its integrated narrowband filter 12 precisely filters out light outside this band, allowing the detector to receive only infrared light within the 900-1250nm range. Similarly, for the interference determination infrared light detector 2 (responding to Band II within the 1251-1350nm range) and the second measuring infrared light detector 4 (with Band III within the 1351-1700nm range), their respective narrowband filters 12 ensure that the detectors are sensitive only to light within their corresponding wavelengths, effectively improving the specificity of the optical signal.

[0077] The width of the infrared light detector response band can be set by the narrowband filter 12. For example, in some scenarios with higher precision requirements, the response band I of the first measuring infrared light detector 3 can be set to 1000~1002nm by the narrowband filter 12; and in some scenarios with lower precision requirements, the response band I of the first measuring infrared light detector 3 can be set to 1000~1050nm by the narrowband filter 12, and so on.

[0078] Detecting water content in petroleum relies on the precise measurement of infrared light in specific wavelength bands. Narrowband filters 12 ensure that the optical signal received by each detector accurately reflects the light absorption in that specific wavelength band, reducing interference from light in other wavelengths and thus improving the accuracy of water content calculations. Without narrowband filters 12, light in other wavelengths might be mistakenly received by the detector, resulting in inaccurate optical signal intensity measurements and, in turn, affecting the water content calculation.

[0079] Example 2:

[0080] like Figure 3 As shown, this embodiment provides a method for detecting water content in petroleum, which is applied to the petroleum water content detection device of embodiment 1. The specific steps include:

[0081] S1 constructs relationship model I and relationship model II between the light signals detected by the first measuring infrared light detector and the second measuring infrared light detector and the water content of the petroleum.

[0082] The theoretical basis for constructing the relationship model is the Lambert-Beer law, which states that when light passes through a homogeneous medium, the degree of light attenuation is proportional to the concentration of the medium and the distance the light propagates within it. In the context of detecting water content in oil, the water and crude oil in the oil have different absorption capacities for infrared light of different wavelengths, which forms the physical basis for constructing the model. When infrared light of different wavelengths passes through oil containing different water contents, its intensity changes accordingly. By measuring this intensity change, the water content in the oil can be inferred.

[0083] The infrared detector's response range for the first measurement is Band I (between 900 and 1250 nm, and between 1000 and 1300 nm). In this band, water-free oil and water have different absorption coefficients for infrared light. The relationship between the intensity of the light signal detected by the infrared detector and the water content of the oil is modeled as follows:

[0084] ;

[0085] The response range of the second infrared light detector is band III (within the range of 1351-1700 nm). The relationship model II between the intensity of the light signal detected by the second infrared light detector and the water content in oil is:

[0086] ;

[0087] Wherein, I1 is the intensity of the light signal detected by the first infrared light detector, I3 is the intensity of the light signal detected by the second infrared light detector, d is the height of the detection channel, a1 is the optical absorption coefficient of water-free petroleum to infrared light in band I, a3 is the optical absorption coefficient of water-free petroleum to infrared light in band III, b1 is the optical absorption coefficient of water to infrared light in band I, b3 is the optical absorption coefficient of water to infrared light in band III, and w is the volume percentage of water in the petroleum to be detected. To detect the presence of air in the flow channel, first measure the intensity of the light signal detected by the infrared light detector. The second measurement is to measure the intensity of the light signal detected by the infrared light detector when there is air in the flow channel.

[0088] By establishing a quantitative relationship between optical signal intensity and water content, theoretically, in a non-interference environment, when the detector detects optical signal intensities I1 and I3, combined with the known absorption coefficients a1, a3, b1, b3, and optical path length d, the water content w in the oil can be calculated through mathematical calculation. The two models complement each other, improving the accuracy and reliability of water content detection. Different wavelengths have different absorption characteristics for oil and water. Combining information from both wavelengths can provide a more comprehensive and accurate picture of the water content in oil, reducing the potential errors associated with single-band detection.

[0089] S2 uses infrared light emitted by an infrared light source to illuminate the oil to be detected, and uses three infrared light detectors to collect the transmitted light signals respectively.

[0090] According to the configuration of the first embodiment, the oil to be tested is allowed to flow through the testing channel, the infrared light emitted by the infrared light source illuminates the oil to be tested, and the three infrared light detectors respectively collect the transmitted light signals.

[0091] S3 will interfere with the light signal detected by the infrared light detector The theoretical optical signal in a non-interference scenario For comparison, if the determination coefficient >1, it is determined that the oil to be detected has sand and gravel interference; if the determination coefficient If the value is less than 1, it is determined that the oil to be detected has bubble interference.

[0092] The interference determination infrared light detector has a response band of 1400-1500nm. In this band, the interference determination infrared light detector detects consistent light signal intensity for oil with any water content in a non-interference scenario.

[0093] Leveraging this characteristic, interference-detecting infrared light detectors are used in oil water content detection devices to identify the presence of interfering substances such as sand, gravel, and bubbles in oil samples. In an ideal, interference-free scenario, the optical signal intensity detected by this detector remains constant regardless of the oil's water content. This means that, without considering external interfering factors such as sand, gravel, and bubbles, changes in the oil's water content will not cause changes in the detector's optical signal intensity.

[0094] In the absence of sand, gravel or air bubble interference, the intensity of the light signal received by the interference determination infrared light detector is always a fixed value, regardless of whether the water content of the oil sample is 10% or 50%.

[0095] The presence of interfering substances changes the propagation characteristics of light in oil, causing the intensity of the light signal received by the detector to vary. Sand and gravel in oil scatter and absorb some infrared light, weakening the light signal reaching the detector. However, the presence of bubbles, because air has little absorption of infrared light, strengthens the light signal received by the detector.

[0096] The determination coefficient k is calculated by comparing the actual light signal intensity detected by the interference determination infrared light detector with the theoretical light signal intensity in a non-interference scenario. If the determination coefficient k is greater than 1, the actual light signal intensity is stronger than in a non-interference scenario, consistent with the characteristic of bubble interference that enhances light signals. Therefore, the oil being tested is determined to have bubble interference. If the determination coefficient k is less than 1, the actual light signal intensity is less than the theoretical value, indicating that factors are weakening the light signal, consistent with the characteristics of sand and gravel interference. Therefore, the oil being tested is determined to have sand and gravel interference.

[0097] In addition, in this embodiment, the data with k=1 is deleted because it is almost impossible to have a completely interference-free situation in actual production. Even if the sand and stone interference and bubble interference cancel each other out and make k=1, it can be treated as coincidental data and deleted.

[0098] S4 brings the determination relation k into relation model I and relation model II to obtain the water content of the oil to be tested.

[0099] In real-world oil detection scenarios, oil is not pure; it often contains impurities such as sand, gravel, and bubbles. These impurities interfere with infrared light propagation, affecting the intensity of the optical signal received by the detector. Interference-determining infrared light detectors compare the actual optical signal with a theoretical optical signal in an interference-free scenario to determine the determination coefficient k. k reflects the extent and direction of the interference's impact on the optical signal. In the presence of interference, directly using the original model to calculate water content without considering k to modify the relationship model will result in significant deviations. Therefore, k is incorporated into Relationship Models I and II to compensate for the effects of interference and ensure that the calculated results are closer to the actual water content of the oil.

[0100] S41, when the oil to be detected has sand and gravel interference, substitute the determination coefficient k into the relationship model I and relationship model II. The determination coefficient k reflects the degree of change in the light signal caused by the sand and gravel interference. Because sand and gravel will scatter and absorb infrared light, the intensity of the light signal received by the detector is weakened, so k>1. K is compared with the actual detected light signal intensity. and Combining these two methods and reconstructing the equation, we can more accurately describe the relationship between the optical signal and the water content in oil, specifically:

[0101] ;

[0102] ;

[0103] in, The intensity of the light signal detected by the infrared light detector is first measured under the interference of sand and gravel. is the light signal intensity detected by the second infrared light detector under the interference of sand and gravel, k is the determination coefficient, d is the height of the detection flow channel, a1 is the optical absorption coefficient of oil without water to infrared light in band I, a3 is the optical absorption coefficient of oil without water to infrared light in band III, b1 is the optical absorption coefficient of water to infrared light in band I, b3 is the optical absorption coefficient of water to infrared light in band III, w is the volume percentage of water in the oil to be detected, To detect the presence of air in the flow channel, first measure the intensity of the light signal detected by the infrared light detector. To detect the intensity of the light signal detected by the second infrared light detector when there is air in the flow channel, For relational model I, For Relationship Model II;

[0104] By minimizing the error function:

[0105] ;

[0106] Solve the water content in the oil to be tested; where N is the relationship model number, is the relational model numbered N, k is the determination coefficient, is the optical signal strength of the relational model numbered N, is the adjustable accuracy threshold I.

[0107] The goal of minimizing the error function is to find a value w that minimizes the difference between the theoretical value and the actual value. Mathematically, optimization algorithms (such as gradient descent) can be used to find a w that satisfies these conditions. is an adjustable precision threshold that controls the precision of the solution. A larger value can produce more accurate water content results, but the calculation workload may increase; The value calculation speed may be faster, but the accuracy of the result will be reduced. It needs to be adjusted according to actual needs.

[0108] When the oil to be detected has air bubble interference, S42 uses the formula:

[0109] ;

[0110] The detection flow channel height is corrected; where d2 is the corrected detection flow channel height, d is the detection flow channel height, k is the determination coefficient, and G is a constant related to the oil and water absorption coefficients.

[0111] The presence of bubbles alters the light propagation path and absorption characteristics in oil. The determination coefficient k reflects the change in the light signal caused by bubble interference, while the constant G, which is related to the absorption coefficients of oil and water, comprehensively accounts for the absorption characteristics of oil and water for infrared light in different wavelengths. Using this formula, the detection channel height d is corrected based on k and G to obtain d2. This corrected channel height more accurately reflects light propagation in oil with bubble interference.

[0112] Substitute the corrected detection flow channel height d2 and determination coefficient k into relationship model I and relationship model II, specifically:

[0113] ;

[0114] ;

[0115] in, The intensity of the light signal detected by the infrared light detector is first measured under the interference of sand and gravel. is the light signal intensity detected by the second infrared light detector under the interference of sand and gravel, k is the determination coefficient, d2 is the height of the corrected detection flow channel, a1 is the optical absorption coefficient of oil without water to infrared light in band I, a3 is the optical absorption coefficient of oil without water to infrared light in band III, b1 is the optical absorption coefficient of water to infrared light in band I, b3 is the optical absorption coefficient of water to infrared light in band III, w is the volume percentage of water in the oil to be detected, To detect the presence of air in the flow channel, first measure the intensity of the light signal detected by the infrared light detector. To detect the intensity of the light signal detected by the second infrared light detector when there is air in the flow channel, For relational model I, For Relationship Model II;

[0116] By minimizing the error function:

[0117] ;

[0118] Solve the water content in the oil to be tested; where N is the relationship model number, is the relational model numbered N, k is the determination coefficient, is the optical signal strength of the relational model numbered N, is the adjustable accuracy threshold II.

[0119] By minimizing the error function, we can find the water content w that minimizes the difference between the theoretical value and the actual value. Controls the accuracy of the solution, smaller More accurate water content results can be obtained, but the amount of calculation may increase; larger The calculation may be faster, but the accuracy of the results will be reduced.

[0120] It should be noted that, in this document, the terms "comprises," "includes," or any other variations thereof are intended to encompass non-exclusive inclusion, such that a process, method, article, or apparatus comprising a series of elements includes not only those elements but also other elements not explicitly listed, or elements inherent to such process, method, article, or apparatus. In the absence of further limitations, an element defined by the phrase "comprising a ..." does not exclude the presence of other identical elements in the process, method, article, or apparatus comprising the element.

[0121] Through the description of the above embodiments, those skilled in the art can clearly understand that the above-mentioned embodiment methods can be implemented by means of software plus the necessary general hardware platform, and of course can also be implemented by hardware, but in many cases the former is a better embodiment. Based on this understanding, the technical solution of the present invention is essentially or the part that contributes to the prior art can be embodied in the form of a software product, which is stored in a storage medium (such as ROM / RAM, magnetic disk, optical disk), including a number of instructions for enabling a computer terminal (which can be a mobile phone, computer, server, or network device, etc.) to execute the methods described in each embodiment of the present invention.

[0122] The embodiments of the present invention are described above in conjunction with the accompanying drawings, but the present invention is not limited to the above-mentioned specific implementation methods. The above-mentioned specific implementation methods are merely illustrative and not restrictive. Under the guidance of the present invention, ordinary technicians in this field can also make many forms without departing from the scope of protection of the present invention and the claims, all of which are protected by the present invention.

Claims

1. A device for detecting water content in petroleum, characterized in that: The invention comprises an infrared light source for emitting infrared light and an infrared light detector for detecting infrared light; the number of the infrared light detectors is three, namely a first measuring infrared light detector having a response range of band I, an interference determination infrared light detector having a response range of band II, and a second measuring infrared light detector having a response range of band III; a detection flow channel for the flow of the oil to be detected is provided between the infrared light source and the detectors, so that the infrared light emitted by the infrared light detector is detected by the three infrared light detectors after passing through the oil to be detected; the invention also comprises a data processing module, the data processing module is used to determine the interference type according to the infrared light intensity detected by the interference determination infrared light detector, and to calculate the water content of the oil to be detected flowing through the detection flow channel using the infrared light intensity detected by the first measuring infrared light detector and the second measuring infrared light detector.

2. A device for detecting water content in petroleum according to claim 1, characterized in that: The band I is located in the range of 900-1250nm, the band II is located in the range of 1251-1350nm, and the band III is located in the range of 1351-1700nm.

3. The device for detecting water content in petroleum according to claim 1, characterized in that: Three infrared light detectors are arranged side by side, and their arrangement direction is perpendicular to the flow direction of the oil to be detected; the infrared light source is opposite to the three infrared light detectors, and two quartz windows are used to isolate the infrared light source from the three infrared light detectors respectively; the interval between the two quartz windows is the detection flow channel.

4. A device for detecting water content in petroleum according to claim 3, characterized in that: The infrared light source is located directly above the three infrared light detectors, and the interval between the two quartz windows is the height of the detection flow channel; the height of the detection flow channel is not greater than 50 cm.

5. The device for detecting water content in petroleum according to claim 1, characterized in that: The infrared light detector is a short-wave infrared photoelectric detector integrated with a narrow-band filter.

6. A method for detecting water content in petroleum, applied to the device for detecting water content in petroleum according to any one of claims 1 to 5, characterized in that include: Relationship models I and II are constructed respectively between the light signals detected by the first infrared light detector and the second infrared light detector and the water content of the oil; The infrared light emitted by the infrared light source illuminates the oil to be detected, and three infrared light detectors are used to collect the transmitted light signals respectively; Interference judgment infrared light detector detected light signal The theoretical optical signal in a non-interference scenario For comparison, if the determination coefficient >1, it is determined that the oil to be detected has sand and gravel interference; if the determination coefficient <1, it is determined that the oil to be detected has bubble interference; Substitute the decision relation k into relation model I and relation model II to obtain the water content of the oil to be tested.

7. A method for detecting water content in petroleum according to claim 6, characterized in that The relationship model I is: ； The relationship model II is: ； Wherein, I1 is the intensity of the light signal detected by the first infrared light detector, I3 is the intensity of the light signal detected by the second infrared light detector, d is the height of the detection channel, a1 is the optical absorption coefficient of water-free petroleum to infrared light in band I, a3 is the optical absorption coefficient of water-free petroleum to infrared light in band III, b1 is the optical absorption coefficient of water to infrared light in band I, b3 is the optical absorption coefficient of water to infrared light in band III, and w is the volume percentage of water in the petroleum to be detected. To detect the presence of air in the flow channel, first measure the intensity of the light signal detected by the infrared light detector. The second measurement is to measure the intensity of the light signal detected by the infrared light detector when there is air in the flow channel.

8. A method for detecting water content in petroleum according to claim 6, characterized in that: The interference determination infrared light detector detects consistent light signal intensity for petroleum with any water content in a non-interference scenario.

9. A method for detecting water content in petroleum according to claim 6, characterized in that In the case where the oil to be detected has sand and gravel interference, the determination coefficient k is substituted into the relationship model I and the relationship model II, specifically: ； ； in, The intensity of the light signal detected by the infrared light detector is first measured under the interference of sand and gravel. is the intensity of the light signal detected by the second infrared light detector under the interference of sand and gravel, k is the determination coefficient, d is the height of the detection flow channel, a1 is the optical absorption coefficient of oil without water to infrared light in band I, a3 is the optical absorption coefficient of oil without water to infrared light in band III, b1 is the optical absorption coefficient of water to infrared light in band I, b3 is the optical absorption coefficient of water to infrared light in band III, w is the volume percentage of water in the oil to be detected, To detect the presence of air in the flow channel, first measure the intensity of the light signal detected by the infrared light detector. To detect the intensity of the light signal detected by the second infrared light detector when there is air in the flow channel, For relational model I, For Relationship Model II; By minimizing the error function: ； Solve the water content in the oil to be tested; where N is the relationship model number, is the relational model numbered N, k is the determination coefficient, is the optical signal strength of the relational model numbered N, is the adjustable accuracy threshold I.

10. A method for detecting water content in petroleum according to claim 6, characterized in that When the oil to be detected has bubble interference, use the formula: ； Correct the detection channel height; where d2 is the corrected detection channel height, d is the detection channel height, k is the determination coefficient, and G is a constant related to the oil and water absorption coefficients; Substitute the corrected detection flow channel height d2 and determination coefficient k into relationship model I and relationship model II, specifically: ； ； in, The intensity of the light signal detected by the infrared light detector is first measured under the interference of sand and gravel. is the light signal intensity detected by the second infrared light detector under the interference of sand and gravel, k is the determination coefficient, d2 is the height of the corrected detection flow channel, a1 is the optical absorption coefficient of oil without water to infrared light in band I, a3 is the optical absorption coefficient of oil without water to infrared light in band III, b1 is the optical absorption coefficient of water to infrared light in band I, b3 is the optical absorption coefficient of water to infrared light in band III, w is the volume percentage of water in the oil to be detected, To detect the presence of air in the flow channel, first measure the intensity of the light signal detected by the infrared light detector. To detect the intensity of the light signal detected by the second infrared light detector when there is air in the flow channel, For relational model I, For Relationship Model II; By minimizing the error function: ； Solve the water content in the oil to be tested; where N is the relationship model number, is the relational model numbered N, k is the determination coefficient, is the optical signal strength of the relational model numbered N, is the adjustable accuracy threshold II.

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