Multi-point thermal field adaptive temperature control method for oil water cut calibration

Abstract

The application discloses a kind of multi-point thermal field adaptive temperature control methods for oil water cut calibration, it is related to thermal field temperature control technical field, for solving the problem that measurement result is difficult to keep measurement repeatability, by the temperature data of different height positions of the sample to be measured under controlled temperature rise condition acquisition, based on temperature gradient feature recognition oil phase, emulsification zone and the temperature stratification interface formed by water phase, and interface upper and lower boundary is used as section division basis, calculate temperature rise lag index, analyze emulsion thickness variation, obtain interface sedimentation rate, based on temperature rise lag index and interface sedimentation rate construct stratified emulsification coefficient, for determining sample emulsification state and water cut error deviation direction, and generate water cut correction coefficient, by stepper motor to the quantitative discharge of stratified section Directional compensation is carried out, and calibration reference is obtained in combination with section, to improve the measurement accuracy under the condition of oil-water interface instability.

Description

Technical Field

[0001] This invention relates to the field of thermal field temperature control technology, and more specifically, to a multi-point thermal field adaptive temperature control method for oil moisture content calibration. Background Technology

[0002] In oilfield development and crude oil processing, water content is a key parameter for measuring crude oil quality and the effectiveness of dehydration processes. The accuracy of its measurement is directly related to crude oil metering and accounting, process control and equipment operation safety. Existing water content detection methods mainly rely on measurement methods such as capacitance, conductivity and near-infrared spectroscopy, but all of them require the sample to be tested in a relatively stable oil-water interface state.

[0003] The existing technology has the following shortcomings:

[0004] Currently, in production sites, due to the multiple components, multiple properties, and shear disturbances of the sampled liquid, the samples often exhibit obvious temperature gradients and emulsified states, making it impossible to achieve stable determination and positioning of the oil-water interface. This leads to deviations in the water content measurement results and makes it difficult to maintain measurement repeatability. Therefore, a multi-point thermal field adaptive temperature control method for oil water content calibration is proposed.

[0005] The information disclosed in the background section is only intended to enhance the understanding of the background of this disclosure, and therefore may include information that does not constitute prior art known to those skilled in the art. Summary of the Invention

[0006] To overcome the aforementioned deficiencies of the prior art, embodiments of the present invention provide a multi-point thermal field adaptive temperature control method for oil water content calibration, which solves the problems mentioned in the background art by employing multi-point temperature gradient analysis and interface sedimentation dynamic fusion modeling technology.

[0007] To achieve the above objectives, the present invention provides the following technical solution: a multi-point thermal field adaptive temperature control method for oil moisture content calibration, comprising the following steps:

[0008] Step S1: Before the oil-water interface of the sample to be tested separates, the temperature data of the sample at each height position in the variable container equipment is obtained by the temperature sensor. The evaluation period is set, and the temperature separation interface of the sample to be tested is analyzed based on the temperature data within the evaluation period.

[0009] Step S2: Divide the sample to be tested into sections according to the temperature stratification interface, retrieve the temperature data of the divided sections to calculate the heating hysteresis index, detect the emulsion thickness of the corresponding divided sections of the temperature stratification interface and analyze the interface sedimentation rate.

[0010] Step S3: Combine the heating hysteresis index and interface settling rate to analyze the stratified settling state, determine the deviation correction direction of the sample to be tested based on the stratified settling state and set the moisture content correction coefficient, and use the deviation correction direction to screen and mark the divided sections.

[0011] Step S4: The stepper motor of the variable container device compensates for the quantitative discharge of the marked segment based on the moisture content correction coefficient, retrieves the moisture content calibration benchmark of the sample to be tested, and generates the moisture content calibration result of the sample to be tested by combining the quantitative discharge.

[0012] In a preferred embodiment, in step S1, before the oil-water interface of the sample to be tested separates into layers, heat input is provided to the sample to be tested through a variable container device according to preset controlled heating conditions.

[0013] Temperature data of the sample under test at different height positions in a variable container device are obtained using a temperature sensor.

[0014] Within the preset evaluation period, the temperature difference is obtained by subtracting the temperature data of the top and bottom positions of the sample to be tested. The moment when the temperature difference reaches the preset temperature difference threshold is recorded as the interface recognition moment.

[0015] In a preferred embodiment, in step S1, the temperature data collected at the interface recognition time are sorted according to the spatial order of height position from bottom to top, and the temperature gradient at each height position is calculated for the sorted temperature data.

[0016] If the temperature gradient is greater than the preset rate of change threshold, the corresponding height position will be marked.

[0017] Conversely, do not mark the height position;

[0018] All marker height positions are sorted sequentially according to height. Adjacent marker height positions are combined into a temperature layering interface. In the temperature layering interface, the upper and lower boundaries of the height positions are used as the upper and lower boundaries of the temperature layering interface, respectively.

[0019] In a preferred embodiment, in step S2, the upper oil phase section is determined by the height range of the combination of the upper boundary of the temperature stratification interface as the lower boundary of the oil phase section and the top position of the sample to be tested.

[0020] The lower aqueous phase section is defined by the height range between the lower boundary of the temperature stratification interface and the bottom position of the sample.

[0021] The height range defined by the upper and lower boundaries of the temperature stratification interface is the middle emulsification zone.

[0022] Before the controlled heating conditions begin, record the initial temperature of the sample to be tested before the controlled heating. During the controlled heating condition stage, select the center position of the aqueous phase section from the lower aqueous phase section as the reference measuring point, and select the center position of the emulsified section from the middle emulsified section as the emulsification measuring point.

[0023] In a preferred embodiment, in step S2, the target temperature rise data of the controlled heating condition is retrieved, and the time taken for the initial temperature of the reference measuring point and the emulsification measuring point to reach the target temperature rise data is used as the reference response time and the emulsification response time, respectively.

[0024] The heating hysteresis index is calculated by taking the reference response time and the emulsification response time.

[0025] After calculating the thermal response hysteresis, stop applying controlled heating conditions to the sample under test, and take the height range of the middle emulsification zone as the emulsification thickness.

[0026] The preset analysis cycle calculates the temperature gradient at each height position in the central emulsification zone at fixed time intervals.

[0027] After the preset analysis cycle ends, the height positions where the temperature gradient is greater than the preset rate threshold are counted, and the difference between the maximum and minimum values ​​of these height positions is used to obtain the emulsion thickness after sedimentation.

[0028] The interface settling rate was calculated based on the emulsion thickness and the emulsion thickness after settling.

[0029] In a preferred embodiment, in step S3, a differential index fusion formula is constructed based on the heating hysteresis index and the interface settling rate. The heating hysteresis index and the interface settling rate are mapped in the form of an exponential difference to obtain the stratification emulsification coefficient of the sample to be tested. ;

[0030] in, The emulsification coefficient is the stratified emulsification factor. The warming lag index, For the interface settling rate, and The preset weighting coefficients, It is a natural exponential function;

[0031] When the stratification emulsification coefficient is greater than or equal to the preset stratification emulsification threshold, the current sample is determined to be in a stable emulsification state.

[0032] When the stratification emulsification coefficient is less than the preset stratification emulsification threshold, the current sample is determined to be in an accelerated settling state.

[0033] In a preferred embodiment, in step S3, when the stratification and settling state is determined to be a stable emulsification state, the deviation correction direction is set to the negative correction direction.

[0034] Conversely, when the stratified settlement state is determined to be an accelerated settlement state, the deviation correction direction is set to the positive correction direction.

[0035] The moisture content correction factor is quantitatively set based on the difference between the stratification emulsification coefficient and the stratification emulsification threshold. The setting expression is: ;

[0036] in, This is the moisture content correction factor. The emulsification coefficient is the stratified emulsification factor. The threshold for layered emulsification is α, which is a preset adjustment coefficient used to control the correction magnitude.

[0037] Apply the deviation correction direction to the segmentation: mark the segmentation in the negative correction direction as the segment with high emulsification;

[0038] The sections that are in the positive correction direction are marked as sections with higher settlement.

[0039] In a preferred embodiment, in step S4, when the segment is marked as a high emulsification segment, the stepper motor of the variable container device will reduce the metered discharge amount, and the compensated metered discharge amount is recorded as: ;

[0040] in, This is the compensated quantitative discharge amount. This is the original quantitative discharge amount. This is the moisture content correction factor;

[0041] Conversely, when a section is marked as having high settlement, the stepper motor of the variable container equipment will proportionally increase the quantitative discharge, with the compensation formula being: .

[0042] In a preferred embodiment, in step S4, the moisture content calibration references for each segment stored in the calibration database are called. The moisture content calibration reference is a single calibration parameter used to reflect the standard moisture content increment corresponding to a unit response change.

[0043] The total discharge is obtained by summing the quantitative discharge amounts after compensation for all segments.

[0044] The volume weight of each segment is then obtained by dividing the compensated quantitative discharge amount of each segment by the total discharge amount.

[0045] By combining volume weighting with the moisture content calibration benchmark, the moisture content calibration result of the sample to be tested is generated based on the volume weighting principle: ;

[0046] in, The calibration results are for the moisture content of the sample to be tested. The volume weights for each segment are: To establish a benchmark for the moisture content of each divided section, For each segment, This represents the total number of segments.

[0047] The technical effects and advantages of this invention are as follows:

[0048] This invention collects temperature data at different heights of the sample under controlled heating conditions, identifies the temperature stratification interface formed by the oil phase, emulsion zone, and water phase based on temperature gradient characteristics, and uses the upper and lower boundaries of the interface as the basis for segment division. It calculates the heating hysteresis index, analyzes the changes in emulsion thickness, obtains the interface settling rate, and constructs a stratified emulsion coefficient based on the heating hysteresis index and interface settling rate to determine the sample emulsion state and the direction of water content error deviation. A water content correction coefficient is also generated. A stepper motor is used to directionally compensate for the quantitative discharge of the stratified segments, and the water content calibration result is obtained by combining the segment calibration benchmark. This achieves dynamic correction of the water content measurement process and improves the measurement accuracy under unstable oil-water interface conditions. Attached Figure Description

[0049] Figure 1 This is a flowchart illustrating the implementation of a multi-point thermal field adaptive temperature control method for oil moisture content calibration according to the present invention.

[0050] Figure 2 This is a schematic diagram illustrating the steps of a multi-point thermal field adaptive temperature control method for oil moisture content calibration according to the present invention. Detailed Implementation

[0051] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0052] This invention collects temperature data at different heights of the sample under controlled heating conditions, identifies the temperature stratification interface formed by the oil phase, emulsion zone, and water phase based on temperature gradient characteristics, and uses the upper and lower boundaries of the interface as the basis for segment division. It calculates the heating hysteresis index, analyzes the changes in emulsion thickness, obtains the interface settling rate, and constructs a stratified emulsion coefficient based on the heating hysteresis index and interface settling rate to determine the sample emulsion state and the direction of moisture content error deviation. A moisture content correction coefficient is also generated. A stepper motor is used to directionally compensate for the quantitative discharge of the stratified segments, and the moisture content calibration result is obtained by combining the segment calibration benchmark, thus realizing dynamic correction of the moisture content measurement process.

[0053] Example 1, as Figures 1 to 2 As shown, a multi-point thermal field adaptive temperature control method for oil moisture content calibration includes the following steps:

[0054] Step S1: Before the oil-water interface of the sample to be tested separates, the temperature data of the sample at each height position in the variable container equipment is obtained by the temperature sensor. The evaluation period is set, and the temperature separation interface of the sample to be tested is analyzed based on the temperature data within the evaluation period.

[0055] Step S2: Divide the sample to be tested into sections according to the temperature stratification interface, retrieve the temperature data of the divided sections to calculate the heating hysteresis index, detect the emulsion thickness of the corresponding divided sections of the temperature stratification interface and analyze the interface sedimentation rate.

[0056] Step S3: Combine the heating hysteresis index and interface settling rate to analyze the stratified settling state, determine the deviation correction direction of the sample to be tested based on the stratified settling state and set the moisture content correction coefficient, and use the deviation correction direction to screen and mark the divided sections.

[0057] Step S4: The stepper motor of the variable container device compensates for the quantitative discharge of the marked segment based on the moisture content correction coefficient, retrieves the moisture content calibration benchmark of the sample to be tested, and generates the moisture content calibration result of the sample to be tested by combining the quantitative discharge.

[0058] The specific implementation is as follows:

[0059] In step S1, during the oil water content detection process, the presence of emulsion structure makes it difficult to identify the oil-water interface, and the stratification process of the oil phase and water phase requires a certain amount of time to stabilize. Temperature stratification is formed by the difference in thermal conductivity of the oil phase, water phase and emulsion mixture. Before collecting temperature data, controlled heating conditions are applied to the sample to be tested, and a measurable temperature stratification phenomenon is formed during the heating process, so as to obtain the position of the oil-water interface and the range of the emulsion section before the stratification is stable.

[0060] Before the oil-water interface of the sample to be tested separates, temperature data of the sample at different heights in the variable container equipment is obtained by temperature sensor. The temperature data reflects the differences in thermal response characteristics of different phase regions of the sample under controlled heating conditions.

[0061] Applying controlled heating conditions refers to providing a stable and uniform heat input to the sample under test through a variable container device according to preset controlled heating conditions before temperature data acquisition. This causes the oil phase, water phase, and emulsion mixture to exhibit different thermal response characteristics as the temperature changes over time, thereby forming an identifiable temperature stratification phenomenon before the interface is stably stratified.

[0062] It should be explained that a variable container device refers to an experimental container unit used to apply a controlled temperature field to the sample under test and to achieve quantitative discharge. It includes a piston structure driven by a stepper motor, a container cavity for sealing the sample, and a heating component for uniform temperature control. The temperature sensor is a temperature detection element that performs real-time temperature measurement in crude oil medium and will not experience data drift due to long-term immersion. A high-precision platinum resistance thermometer can be used, and its height and position can be arranged according to the internal dimensions of the variable container device and the expected stratification range of the sample under test. The preset controlled heating conditions refer to the target heating data used to control the heating behavior of the variable container device, which can be set according to the original temperature of the sample under test, the physical properties of the oil, and the target temperature difference.

[0063] Within the preset evaluation period, the temperature difference is obtained by subtracting the temperature data of the top and bottom positions of the sample to be tested. The moment when the temperature difference reaches the preset temperature difference threshold is recorded as the interface recognition moment.

[0064] For the temperature data collected at the moment of interface recognition, the temperature data are sorted according to the spatial order from bottom to top according to their height position, and the temperature gradient is calculated for the sorted temperature data: ,in, For the first Temperature data at various elevation locations For the first Temperature data at various elevation locations For the first The height position of each. For the first The height position of each. For the i-th temperature gradient;

[0065] A larger temperature gradient indicates that there is a significant obstruction to the heat input at that height, corresponding to a mixed transition zone with a high proportion of emulsion; a smaller temperature gradient indicates that the heat conduction path at that height is more continuous, and the temperature response is faster or slower, corresponding to a relatively homogeneous oil phase region or water phase region.

[0066] The temperature rises rapidly in the upper oil phase section, with a relatively small and gradual temperature gradient; the temperature rises slowly in the lower water phase section, with a small and relatively small temperature gradient and fluctuation; the emulsified section located between the oil and water phases has a complex internal structure and forms a transition zone with a significantly increased temperature gradient in the height direction.

[0067] If the temperature gradient is greater than the preset rate of change threshold, the corresponding height position will be marked.

[0068] Conversely, do not mark the height position;

[0069] All marker height positions are sorted sequentially according to height. Adjacent marker height positions are combined into a temperature layering interface. In the temperature layering interface, the upper and lower boundaries of the height positions are used as the upper and lower boundaries of the temperature layering interface, respectively.

[0070] By applying controlled heating conditions to the sample under test and collecting temperature data at different heights, the temperature gradient is calculated based on the temperature data, and the height range of the emulsified section is identified using a preset rate of change threshold, thereby determining the upper and lower boundary positions of the oil-water interface.

[0071] It should be noted that the preset temperature difference threshold can be set according to the specific heat capacity difference of different phase regions and the target interface recognition sensitivity requirements; the preset change rate threshold can be set according to the actual temperature data of different test samples under controlled heating conditions, so that the temperature gradient higher than the threshold can stably correspond to the emulsification mixing section.

[0072] In step S2, the sample to be tested is divided into sections according to the temperature stratification interface. The upper boundary of the temperature stratification interface is used as the lower boundary of the oil phase section, and the top of the sample to be tested is used as the upper boundary of the upper oil phase section. The height range of the combination of the lower boundary and the upper boundary of the oil phase section is determined as the upper oil phase section.

[0073] The lower boundary of the temperature stratification interface is taken as the upper boundary of the lower aqueous phase section, and the bottom of the sample to be tested is taken as the lower boundary of the lower aqueous phase section. The height range between the upper and lower boundaries of the aqueous phase section is defined as the lower aqueous phase section.

[0074] The section defined by the upper and lower boundaries of the temperature stratification interface is the middle emulsification section.

[0075] Before the controlled heating conditions begin, record the initial temperature of the sample to be tested before the controlled heating. During the controlled heating phase, acquire the temperature data of the sample to be tested at various height positions.

[0076] The center of the aqueous phase section in the lower part of the water phase section was selected as the reference measuring point, and the center of the emulsification section in the middle part of the emulsification section was selected as the emulsification measuring point. Temperature data of the reference measuring point and the emulsification measuring point were collected during the controlled heating process, respectively.

[0077] Retrieve the target temperature rise data under controlled heating conditions. The target temperature rise data refers to the pre-set temperature rise range during the controlled heating stage to reflect the temperature response characteristics of different phase regions under the same heat input conditions.

[0078] The time taken for the temperature data at the reference measuring point to reach the target temperature rise data is taken as the reference response time, and the time taken for the temperature data at the emulsification measuring point to reach the target temperature rise data is taken as the emulsification response time.

[0079] The difference between the reference response time and the emulsification response time is used as the thermal response hysteresis. The thermal response hysteresis is then standardized to obtain the heating hysteresis index.

[0080] The greater the thermal response hysteresis, the more obvious the obstruction effect of the internal structure of the middle emulsification section on heat transfer, and the more hysteretic the thermal response; the smaller the thermal response hysteresis, the closer the temperature response of the middle emulsification section and the lower aqueous phase section, and the clearer the interface structure.

[0081] After calculating the thermal response hysteresis, stop applying controlled heating conditions to the sample under test and allow the variable container equipment to enter the natural settling stage.

[0082] The height range of the central emulsified section is taken as the emulsification thickness. The preset analysis period is used to analyze the interface changes that occur in the central emulsified section during natural settling. Temperature data at each height position is collected at fixed time intervals within the preset analysis period, and the temperature gradient at each height position in the central emulsified section is calculated.

[0083] After the preset analysis cycle ends, the height positions where the temperature gradient is greater than the preset rate threshold are counted, and the difference between the maximum and minimum values ​​of these height positions is used to obtain the emulsion thickness after sedimentation.

[0084] The difference between the emulsion thickness and the emulsion thickness after sedimentation is used to obtain the emulsion thickness difference value. The emulsion thickness difference value is divided by the preset analysis period to obtain the interface sedimentation rate.

[0085] The lower the interface settling rate, the slower the emulsion demulsification process, the more stable the interface structure, and the higher the degree of oil-water mixing. The higher the interface settling rate, the faster the emulsion breaks down, the faster the oil and water droplets separate under gravity, and the clearer the oil-water interface.

[0086] It should be noted that the standardization methods include, but are not limited to, standard linear transformation based on interval scaling, statistical Z-Score standardization, or normalization based on nonlinear mapping functions. The application methods of standardization will not be elaborated here. The preset analysis period can be set according to the historical sedimentation timescale of the sample to be tested and the size characteristics of the variable container equipment. The preset rate threshold can be set according to the historical sedimentation characteristics of the sample to be tested, for example, the preset rate threshold calculated using the median value of the temperature gradient and its median absolute deviation.

[0087] In step S3, considering the inverse trend of the heating hysteresis index and the interface settling rate in terms of physical properties, a feature fusion method based on the index difference is used to analyze the stratified settling state of the sample.

[0088] Specifically, a differential index fusion formula is constructed based on the heating hysteresis index and the interfacial settling rate. The heating hysteresis index and the interfacial settling rate are mapped in the form of an exponential difference, so that they show an inverse proportional contribution relationship in the fusion process, thereby obtaining the layered emulsification coefficient of the sample under test. The differential index fusion formula is shown below:

[0089] ;

[0090] in, The emulsification coefficient is the stratified emulsification factor. The warming lag index, For the interface settling rate, and The preset weighting coefficients, It is a natural exponential function.

[0091] An increase in the heating hysteresis index will enhance the stratified emulsification coefficient, thus indicating that the internal structure of the emulsion layer is more stable; while an increase in the interfacial settling rate will cause the stratified emulsification coefficient to decrease exponentially, thus reflecting the trend of rapid settling and loose structure of the emulsion layer.

[0092] The stratification emulsification coefficient is compared with the preset stratification emulsification threshold. When the stratification emulsification coefficient is greater than or equal to the preset stratification emulsification threshold, the current sample is determined to be in a stable emulsification state, indicating that the emulsion layer is thick and the settling rate is low. When the stratification emulsification coefficient is less than the preset stratification emulsification threshold, the current sample is determined to be in an accelerated settling state, indicating that the emulsion layer has a clear tendency to break down and the dynamic changes of the oil-water interface are significant.

[0093] It should be noted that the stratification threshold is set based on the typical stratification behavior of historical samples. A joint calibration experiment using the heating hysteresis index and interfacial settling rate was conducted on multiple groups of samples with known emulsification states. The corresponding stratification emulsification coefficient distribution intervals were calculated, and the coefficient intervals for samples in a stable emulsification state and those in an accelerated settling state were statistically segmented. Specifically, historical samples were labeled according to their actual observed stratification behavior. The mean and standard deviation of the stratification emulsification coefficient were calculated for samples exhibiting stable emulsification and slow settling, and the median of the sum of the mean and standard deviation was used as the stratification emulsification threshold.

[0094] After obtaining the stratified sedimentation state based on the fusion model, the directional correction of the moisture content measurement error of the sample to be tested is further performed based on the stratified sedimentation state.

[0095] Specifically, when the stratified settling state is determined to be a stable emulsion state, it indicates that the emulsion layer is thick and the oil-water interface settles slowly. During the sampling process, the water content is more likely to be high due to the entrainment of the emulsion layer. Therefore, the deviation correction direction is set to the negative correction direction, so that the water content correction coefficient is applied downward to the original quantitative discharge amount in the subsequent calculation.

[0096] Conversely, when the stratified settling state is determined to be accelerated settling state, it indicates that the oil-water interface structure is loose and the settling is rapid. The water phase ratio in the sampled liquid is more likely to be low. At this time, the deviation correction direction is set to the positive correction direction, so that the water content correction coefficient is applied to the original quantitative discharge in subsequent calculations.

[0097] The moisture content correction factor is quantitatively set based on the difference between the stratification emulsification coefficient and the stratification emulsification threshold. The setting expression is:

[0098] ;

[0099] in, This is the moisture content correction factor. The emulsification coefficient is the stratified emulsification factor. α is the threshold for layered emulsification, and α is an adjustment coefficient used to control the correction magnitude.

[0100] Subsequently, the deviation correction direction is applied to the segmentation: the segmentation in the negative correction direction is marked as the high emulsification segment, and the corresponding moisture content deviation is deducted in subsequent data processing;

[0101] The sections in the positive correction direction are marked as sections with high settlement to compensate for the risk of underestimation of water content caused by rapid interface stratification.

[0102] Through the above process, the sources of deviation in different division sections are identified in a targeted manner, so that the moisture content correction process has both spatial resolution and physical correspondence, thereby improving the accuracy of the overall moisture content measurement.

[0103] In step S4, the moisture content correction coefficients and corresponding deviation correction directions generated for each segment are read. The quantitative discharge amount of each segment is used as the base amount, and linear compensation is performed according to the correction direction. Specifically, when a segment is marked as a high emulsification segment (corresponding to a negative correction direction), it indicates that the proportion of the aqueous phase in the collected liquid is overestimated. The stepper motor will reduce the quantitative discharge amount of the sample in that segment. The compensated quantitative discharge amount is recorded as:

[0104] ;

[0105] in, This is the compensated quantitative discharge amount. This is the original quantitative discharge amount. This is the moisture content correction factor.

[0106] Conversely, when a section is marked as having high settlement (corresponding to the positive correction direction), it indicates that the water phase ratio is underestimated. The stepper motor will proportionally increase the quantitative discharge, and the compensation formula is as follows:

[0107] ;

[0108] It should be noted that the quantitative discharge volume refers to the volume of sample discharged by the piston driven by the stepper motor within a set stroke when the variable container equipment performs the oil-water sample discharge operation. It is used to characterize the volume distribution and aqueous phase contribution of each segment in the actual liquid discharge process. The stepper motor is a drive unit installed in the variable container equipment, which is used to drive the quantitative discharge component to achieve controllable adjustment of the discharge volume.

[0109] After completing the discharge compensation, the water content calibration benchmarks for each segment stored in the calibration database are called. The water content calibration benchmark is a single calibration parameter used to characterize the water content response characteristics of oil-water mixed samples under specific measurement conditions and to convert water content. It is used to reflect the standard water content increment corresponding to a unit response change.

[0110] It should be noted that the calibration database is a collection of information used to store the moisture content calibration reference parameters, discharge stroke calibration data, stratification judgment thresholds and corresponding correction rules for each segment after quantitative discharge compensation. Based on the segment index as the basic index structure, the upper oil phase segment, the middle emulsified segment and the lower aqueous phase segment in the sample height direction are set as independent data recording units, and the corresponding moisture content calibration reference parameters are stored in each data recording unit.

[0111] After the compensation discharge amount and calibration benchmark have been determined, the overall sample moisture content is calibrated and calculated. Specifically, the quantitative discharge amounts after compensation for all divided sections are summed to obtain the total discharge amount.

[0112] The volume weight of each segment is then obtained by dividing the compensated quantitative discharge amount of each segment by the total discharge amount.

[0113] By combining volume weighting with the moisture content calibration benchmark, the moisture content calibration result of the sample to be tested is generated based on the volume weighting principle. The specific expression is as follows:

[0114] ;

[0115] in, The calibration results are for the moisture content of the sample to be tested. The volume weights for each segment are: To establish a benchmark for the moisture content of each divided section, For each segment, This represents the total number of segments.

[0116] Finally, it should be noted that in this paper, relational terms such as first and second are used only to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations.

[0117] Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0118] In this document, the singular forms “a,” “an,” and “the” may also include the plural forms unless the context clearly indicates otherwise. It should also be understood that terms such as “comprising / including” or “having” specify the presence of the stated features, integrals, steps, operations, components, parts, or combinations thereof, but do not preclude the possibility of the presence or addition of one or more other features, integrals, steps, operations, components, parts, or combinations thereof. Meanwhile, the term “and / or” as used in this specification includes any and all combinations of the associated listed items.

[0119] The various embodiments in this specification are described in a progressive manner. Each embodiment focuses on the differences from other embodiments. The various embodiments can be combined as needed, and the same or similar parts can be referred to each other.

[0120] The above description of the disclosed embodiments will enable those skilled in the art to make or use various modifications to these embodiments. It will be readily apparent to those skilled in the art that the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of this application. Therefore, this application is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A multi-point thermal field adaptive temperature control method for oil water cut calibration, characterized in that: The method comprises the following steps: Step S1: Before the oil-water interface of the sample to be tested is layered, the temperature data of the sample to be tested at different height positions in the variable container device are obtained by a temperature sensor, an evaluation period is set, and the temperature stratification interface of the sample to be tested is analyzed according to the temperature data in the evaluation period; Step S2: The sample to be tested is segmented according to the temperature stratification interface, the temperature data of the segmented section are called, the temperature rise hysteresis index is calculated, the emulsion thickness of the segmented section corresponding to the temperature stratification interface is detected, and the interface sedimentation rate is analyzed; Step S3: The temperature rise hysteresis index and the interface sedimentation rate are fused to analyze the stratification and sedimentation state, the deviation correction direction of the sample to be tested is determined according to the stratification and sedimentation state, the water content correction coefficient is set, and the deviation correction direction is used to screen and mark the segmented section; Step S4: The stepping motor of the variable container device compensates the quantitative discharge amount of the marked segmented section based on the water content correction coefficient, the water content calibration reference of the sample to be tested is called, and the water content calibration result of the sample to be tested is generated in combination with the quantitative discharge amount.

2. The multi-point thermal field adaptive temperature control method for petroleum water content calibration according to claim 1, characterized in that: In step S1, before the oil-water interface of the sample to be tested is layered, the variable container device provides heat input to the sample to be tested under a preset controlled temperature rise condition; The temperature data of the sample to be tested at different height positions in the variable container device are obtained by a temperature sensor; In a preset evaluation period, the temperature data of the top position and the bottom position of the sample to be tested are subtracted to obtain a temperature difference value, and the time when the temperature difference value reaches a preset temperature difference threshold is recorded as the interface recognition time.

3. The multi-point thermal field adaptive temperature control method for petroleum water content calibration according to claim 2, characterized in that: In step S1, for each temperature data collected at the interface recognition time, the temperature data are sorted in a spatial order from bottom to top according to the height position, and the temperature gradient of each height position is calculated for the sorted temperature data; If the temperature gradient is greater than a preset change rate threshold, the corresponding height position is marked; Otherwise, the height position is not marked; For all marked height positions, the adjacent marked height positions are combined as a temperature stratification interface, and the upper and lower boundaries of the height position are used as the upper boundary and the lower boundary of the temperature stratification interface, respectively.

4. The multi-point thermal field adaptive temperature control method for petroleum water content calibration according to claim 3, characterized in that: In step S2, the height range combined with the lower boundary of the oil phase section and the top position of the sample to be tested is determined as the upper oil phase section with the upper boundary of the temperature stratification interface as the lower boundary; The height range determined with the lower boundary of the temperature stratification interface and the bottom position of the sample to be tested is determined as the lower water phase section; The height section defined by the upper and lower boundaries of the temperature stratification interface is the middle emulsion section; Before the controlled temperature rise condition starts, the initial temperature of the sample to be tested before the controlled temperature rise is recorded, the center position of the water phase section is selected as a reference measurement point from the lower water phase section, and the center position of the emulsion section is selected as an emulsion measurement point from the middle emulsion section.

5. The multi-point thermal field adaptive temperature control method for petroleum water cut calibration according to claim 4, characterized in that: In step S2, the target temperature rise data of the controlled temperature rise condition is called, and the time taken by the initial temperatures of the reference measuring point and the emulsification measuring point to reach the target temperature rise data is taken as the reference response time and the emulsification response time, respectively; The temperature rise hysteresis index is calculated based on the reference response time and the emulsification response time; After the thermal response hysteresis amount is calculated, the controlled temperature rise condition applied to the sample under test is stopped, and the height range of the middle emulsification section is taken as the emulsification thickness; The analysis period is preset, and the temperature gradient of each height position of the middle emulsification section is calculated at a fixed time interval; After the preset analysis period ends, the height positions with a temperature gradient greater than the preset rate threshold value are counted, and the maximum value and the minimum value of the height positions are subtracted to obtain the emulsification thickness after settling; The interface settling rate is calculated based on the emulsification thickness and the emulsification thickness after settling.

6. The multi-point thermal field adaptive temperature control method for petroleum water cut calibration according to claim 5, characterized in that: In step S3, a differential exponential fusion formula is constructed based on the temperature rise hysteresis index and the interface sedimentation rate, the temperature rise hysteresis index and the interface sedimentation rate are mapped in the form of exponential difference, and thus the stratified emulsification coefficient of the sample to be tested is obtained: ; wherein, is a stratification emulsification coefficient, is a temperature rise hysteresis index, is an interfacial sedimentation rate, and is a preset weight coefficient, is a natural exponential function; When the stratified emulsification coefficient is greater than or equal to the preset stratified emulsification threshold value, it is determined that the current sample is in a stable emulsification state; When the stratified emulsification coefficient is less than the preset stratified emulsification threshold value, it is determined that the current sample is in an accelerated settling state.

7. The multi-point thermal field adaptive temperature control method for petroleum water cut calibration according to claim 6, characterized in that: In step S3, when the stratified settling state is determined to be a stable emulsification state, the deviation correction direction is set to a negative correction direction; Conversely, when the stratified settling state is determined to be an accelerated settling state, the deviation correction direction is set to a positive correction direction; The water content correction coefficient is quantitatively set according to the difference relationship between the stratified emulsification coefficient and the stratified emulsification threshold value, and the setting expression is: ; wherein, is a water content correction coefficient, is a stratified emulsion coefficient, is a stratified emulsion threshold value, and a is a preset adjustment coefficient for controlling the correction range. The deviation correction direction is applied to the division section: the division section in the negative correction direction is marked as an emulsification high section; The division section in the positive correction direction is marked as a settling high section.

8. The multi-point thermal field adaptive temperature control method for petroleum water cut calibration according to claim 1, characterized in that: In step S4, when the division section is marked as an emulsification high section, the step motor of the variable container device will reduce the dosing discharge amount, and the compensated dosing discharge amount is recorded as: ; wherein, Qcomp is the compensated dosing quantity, Qorig is the original dosing quantity, Cw is the water content correction factor; Conversely, when the division section is marked as a high-settlement section, the stepping motor of the variable-volume device will proportionally increase the quantitative discharge amount, and its compensation formula is: .

9. The multi-point thermal field adaptive temperature control method for petroleum water cut calibration according to claim 8, characterized in that: In step S4, the water cut calibration reference of each division section stored in the calibration database is called, and the water cut calibration reference is a single calibration parameter used to reflect the corresponding standard water cut increment under unit response change; The compensated quantitative discharge amounts of all division sections are summed to obtain the total discharge amount; Then, the compensated quantitative discharge amounts of each division section are divided by the total discharge amount to obtain the volume weight of each division section; The volume weight is combined with the water content calibration benchmark to generate the water content calibration result of the sample to be tested based on the volume weighting principle: ; wherein, is a moisture content calibration result of the sample to be measured, is a volume weight of each division section, is a moisture content calibration reference of each division section, is an index value of each division section, is a total number of division sections.

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