A method and system for calculating separate layer flow based on DTS logging data

Abstract

The application provides a layered flow calculation method and system based on DTS logging data, which can improve the inversion accuracy of DTS logging layered flow, simplify the analysis and calculation process, and improve the accuracy of the calculation result. The method comprises the following steps: collecting the shut-in temperature and the open-in temperature of each sampling point of each layer of the formation, and drawing a shut-in temperature curve and an open-in temperature curve according to the shut-in temperature and the open-in temperature, wherein the formation comprises a perforated layer and a non-perforated layer; obtaining the temperature difference of the perforated layer and the temperature difference of the non-perforated layer, and calculating the difference between the temperature difference of the perforated layer and the temperature difference of the non-perforated layer as a pure temperature difference; calculating the flow of each sampling point of the perforated layer according to the pure temperature difference; and calculating the layered flow of each layer of the formation according to the number of sampling points of the perforated layer and the flow of each sampling point.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of oil well logging data interpretation, in particular to a layered flow calculation method and system based on DTS logging data. BACKGROUND

[0002] Full-well-section distributed temperature (DTS) measurement has been widely used in oil and gas resource development. The well fluid production or water injection is calculated according to the measured temperature change of the oil and gas production well section (perforated well section) or the measured temperature change of the water injection well injection section (perforated well section).

[0003] However, due to the limited spatial resolution and temperature measurement sensitivity of the DTS demodulation instrument, there is a certain error in the well temperature change and accurate position measured based on the distributed optical fiber DTS data, which leads to a large error in the perforated section well fluid production or water injection calculated only according to the well temperature change. At present, temperature logging data is mainly used for qualitative analysis, which can only provide auxiliary reference for quantitative interpretation, and cannot accurately calculate the layered flow only according to the change of well temperature.

[0004] In addition, the determination of the interpretation parameters of the distributed optical fiber DTS data processing part is difficult, and these parameters have a great influence on the layered flow result. The geothermal gradient in the interpretation of optical fiber logging data is mainly based on the shut-in temperature curve, and the shut-in temperature monitoring is difficult to reach a steady state. There is a certain difference between the shut-in temperature and the shut-in steady state temperature, and it is difficult to obtain the shut-in steady state temperature. The temperature curve used in the interpretation of optical fiber logging DTS data is the flow temperature curve, which has not been corrected to the steady state. The existing optical fiber logging DTS quantitative interpretation has multiple solutions, which needs to be combined with qualitative analysis and semi-quantitative interpretation for comprehensive interpretation. SUMMARY

[0005] In order to solve the problems in the prior art, the present application provides a layered flow calculation method and system based on DTS logging data, which can improve the inversion accuracy of DTS logging layered flow, simplify the analysis and calculation process, and improve the accuracy of the calculation result.

[0006] To achieve the above purpose, the present application provides the following technical scheme:

[0007] A layered flow calculation method based on DTS logging data, comprising the following steps:

[0008] Collecting the shut-in temperature and the open well temperature of each sampling point of the stratum, and drawing the shut-in temperature curve and the open well temperature curve according to the shut-in temperature and the open well temperature, wherein the stratum includes a perforated layer and a non-perforated layer;

[0009] Obtaining the temperature difference of the perforated layer and the temperature difference of the non-perforated layer, and calculating the difference value of the temperature difference of the perforated layer and the temperature difference of the non-perforated layer as the pure temperature difference;

[0010] According to the pure temperature difference, the flow rate of each sampling point of the perforated layer is calculated.

[0011] According to the number of sampling points of the perforated layer and the flow rate of each sampling point, the flow rate of each sublayer of the formation is calculated.

[0012] Preferably, the non-perforated layer selects the layer above the perforated layer.

[0013] Preferably, the expression of the temperature difference of the perforated layer is:

[0014] ΔT 射孔 = T 射孔关 -T 射孔开 ;

[0015] In the formula, ΔT 射孔 represents the temperature difference of the perforated layer, T 射孔关 represents the shut-in steady-state temperature of the perforated layer, and T 射孔开 represents the open well steady-state temperature of the perforated layer.

[0016] Preferably, the open well steady-state temperature of the perforated layer is selected by:

[0017] Based on the change characteristics of the logarithmic function, the open well temperature value when the temperature rate of change with time is zero is selected from the open well temperature curve of the perforated layer as the open well steady-state temperature.

[0018] Preferably, the expression of the temperature difference of the non-perforated layer is:

[0019] ΔT 非射孔 = T 非射孔关 -T 非射孔开 ;

[0020] In the formula, ΔT 非射孔 represents the temperature difference of the non-perforated layer, T 非射孔关 represents the shut-in steady-state temperature of the non-perforated layer, and T 非射孔开 represents the open well steady-state temperature of the non-perforated layer.

[0021] Preferably, the open well steady-state temperature of the non-perforated layer is selected by:

[0022] The average value of the open well temperature of each sampling point of the non-perforated layer is calculated as the open well steady-state temperature of the non-perforated layer.

[0023] Preferably, the calculation expression for calculating the flow rate of each sampling point of the perforated layer according to the pure temperature difference is:

[0024]

[0025] In the formula, Q i represents the daily water injection rate of the i th sampling point of the perforated layer, Q represents the daily water injection rate of a single well, and ΔT iThe pure temperature difference is represented as the pure temperature difference of the i-th sampling point of the perforated layer, and the sum of the pure temperature differences of all sampling points of the perforated layer is represented as ∑ΔT.

[0026] Preferably, after the shut-in temperature curve is plotted according to the shut-in temperature, the method further comprises:

[0027] Based on the change characteristics of the logarithmic function, the shut-in steady temperature is selected as the shut-in temperature value when the temperature rate of change with time is zero in the shut-in temperature curve.

[0028] A layered flow calculation system based on DTS logging data, comprising:

[0029] A temperature curve plotting module is configured to collect shut-in temperatures and open temperatures of sampling points of each layer of the formation, and plot shut-in temperature curves and open temperature curves according to the shut-in temperatures and the open temperatures, wherein the formation comprises a perforated layer and a non-perforated layer.

[0030] A pure temperature difference calculation module is configured to obtain a temperature difference of the perforated layer and a temperature difference of the non-perforated layer, and calculate a difference between the temperature difference of the perforated layer and the temperature difference of the non-perforated layer as a pure temperature difference.

[0031] A sampling point flow calculation module is configured to calculate a flow of each sampling point of the perforated layer according to the pure temperature difference.

[0032] A layered flow calculation module is configured to calculate a flow of each layer of the formation according to a number of sampling points of the perforated layer and the flow of each sampling point.

[0033] Preferably, the pure temperature difference calculation module comprises an open steady temperature selection module configured to select an open steady temperature as an open temperature value when the temperature rate of change with time is zero in the open temperature curve of the perforated layer based on the change characteristics of the logarithmic function.

[0034] Compared with the prior art, the present application has the following beneficial effects:

[0035] This invention provides a stratified flow rate calculation method based on DTS logging data. Based on DTS fiber optic logging data, it forms a complete stratified flow rate calculation and evaluation process through five steps: determining the shut-in temperature curve, determining the open-in temperature curve, determining the pure temperature difference, determining the flow rate values ​​at each sampling point in the perforation layer, and calculating the stratified flow rate values. According to the calculation method described in this invention, the continuous monitoring characteristics of distributed fiber optic DTS data are fully considered. Based on the temperature curve's time-varying pattern, the temperature changes at each depth point are tracked over time. The temperature difference variation pattern is used to determine the shut-in steady-state temperature curve and the wellbore flow temperature steady-state curve, regressing the shut-in steady-state temperature curve and the steady-state temperature curves for each operating condition, providing accurate data for quantitative calculation. Simultaneously, this invention innovatively proposes the concept of pure temperature difference. Using this method, a semi-quantitative calculation of the stratified flow rate of injection wells can be performed. This semi-quantitative calculation result can determine the flow profile based on the relative change of flow temperature and geothermal temperature, providing a reference for the calculation of the distributed fiber optic DTS data processing and interpretation model. This reduces the ambiguity of DTS data analysis, improves the inversion accuracy of DTS logging stratified flow rate, and simplifies the analysis and calculation process. Attached Figure Description

[0036] Figure 1 This is a flowchart of the hierarchical flow calculation of the present invention;

[0037] Figure 2 This is a block diagram of the hierarchical flow calculation system of the present invention;

[0038] Figure 3 This is a schematic diagram of the temperature change at a certain depth point in the injection well in an embodiment of the present invention;

[0039] Figure 4 This is a schematic diagram of the temperature change at a certain depth point of the injection well in an embodiment of the present invention.

[0040] Figure 5 This is a DTS logging waterfall diagram of a water injection well in an embodiment of the present invention;

[0041] Figure 6 This is a graph showing the temperature change over time at various sampling points in the perforation layer of a water injection well in an embodiment of the present invention.

[0042] Figure 7 This is a pure temperature difference diagram calculated at each sampling point in the perforation layer of a water injection well in an embodiment of the present invention;

[0043] Figure 8 This is a diagram showing the injection volume at each sampling point in the perforation layer of a water injection well in an embodiment of the present invention.

[0044] Figure 9 This is the dynamic analysis process of hierarchical flow calculation in the embodiments of the present invention;

[0045] Figure 10This is a comparison diagram of the stratified flow calculation results and the conventional water absorption profile in the embodiments of the present invention. Detailed Implementation

[0046] The present invention will be further described in detail below with reference to specific embodiments. These descriptions are for explanation purposes only and are not intended to limit the scope of the invention.

[0047] like Figure 1 As shown, the present invention provides a method for calculating layered flow rates based on DTS logging data, comprising the following steps:

[0048] The shut-in temperature and open temperature of each stratum sampling point are collected, and shut-in temperature curves and open temperature curves are plotted based on the shut-in temperature and open temperature. The strata include perforated layers and non-perforated layers.

[0049] Obtain the temperature difference between the perforated layer and the non-perforated layer, and calculate the difference between the temperature difference between the perforated layer and the non-perforated layer as the pure temperature difference;

[0050] Calculate the flow rate at each sampling point in the perforation layer based on the pure temperature difference;

[0051] The flow rates of each formation layer are calculated based on the number of sampling points in the perforated layer and the flow rate at each sampling point.

[0052] This invention provides a method for calculating stratified flow rate based on DTS logging data. Based on distributed fiber optic DTS logging technology, it utilizes the difference between the opening temperature and the shut-in steady-state temperature to perform semi-quantitative calculation of stratified flow rate. The specific method is as follows: First, based on the time-varying patterns of the shut-in and opening temperatures at each sampling point in the perforated zone, and combined with logarithmic function relationships, the shut-in steady-state temperature and opening steady-state temperature values ​​are comprehensively determined. Second, the change in temperature difference between the perforated section and the non-perforated section is determined using the shut-in and opening steady-state temperatures, defined as the pure temperature difference. Then, the flow rate values ​​at each sampling point in the perforated section are calculated using the pure temperature difference, and finally, the stratified flow rate is calculated.

[0053] The calculation method described in this invention fully considers the characteristics of continuous monitoring of distributed fiber optic DTS data. Based on the temperature curve's variation over time, it tracks the temperature changes at each depth point, and uses the temperature difference variation to determine the steady-state temperature curve for shut-in and the steady-state flow temperature curve in the wellbore. It then regresses the shut-in steady-state temperature curve and the steady-state temperature curves for each operating regime, providing accurate data for quantitative calculations. Furthermore, this invention innovatively proposes the concept of pure temperature difference. Using this method, semi-quantitative calculations of stratified flow rates in injection wells can be performed. These semi-quantitative calculation results can determine the flow profile based on the relative changes in flow temperature and geothermal temperature, providing a reference for the calculation of distributed fiber optic DTS data processing and interpretation models. This reduces the ambiguity of DTS data analysis, improves the inversion accuracy of DTS well logging stratified flow rates, and simplifies the analysis and calculation process.

[0054] Preferably, the non-perforated layer is selected from the section near the perforated layer, mainly to remove the influence of wellbore fluid on shut-in recovery temperature and further ensure the accuracy of the collected data and subsequent calculations.

[0055] The expression for the temperature difference in the perforation layer is as follows:

[0056] ΔT 射孔 =T 射孔关 -T 射孔开 ;

[0057] In the formula, △T 射孔 Expressed as temperature difference in the perforation layer, T 射孔关 The shut-in steady-state temperature (T) of the perforated layer is expressed as T. 射孔开 It represents the well-opening steady-state temperature of the perforated layer.

[0058] Furthermore, the selection of the wellhead steady-state temperature of the perforated layer includes:

[0059] like Figure 3 As shown, based on the logarithmic function variation characteristics, the well temperature value at which the rate of temperature change with time is close to zero is selected from the well opening temperature curve of the perforated layer as the well opening steady-state temperature.

[0060] The expression for the temperature difference in the non-perforated layer is as follows:

[0061] ΔT 非射孔 =T 非射孔关 -T 非射孔开 ;

[0062] In the formula, △T 非射孔 Represented as temperature difference in the non-perforated layer, T 非射孔关 The shut-in steady-state temperature (T) of the non-perforated layer is expressed as T. 非射孔开 This represents the steady-state temperature at the opening of the non-perforated layer.

[0063] Furthermore, the selection of the wellbore steady-state temperature of the non-perforated layer includes:

[0064] The average well opening temperature of each sampling point in the non-perforated layer is calculated as the well opening steady-state temperature of the non-perforated layer.

[0065] This invention proposes a pure temperature difference method, which uses the temperature difference between the perforated section and the non-perforated section as the pure temperature difference for water injection to perform semi-quantitative calculation of the stratified flow rate of the water injection well. The results can provide a reference for interpreting model calculations.

[0066] The calculation expression for the flow rate at each sampling point of the perforation layer based on the pure temperature difference is as follows:

[0067]

[0068] In the formula, Qi Q represents the daily water injection amount of a single well, and △T i ∑△T represents the sum of the pure temperature differences of all sampling points of the perforated layer.

[0069] According to the shut-in temperature curve drawn based on the shut-in temperature, the method further comprises the following steps:

[0070] As shown in Figure 4 Based on the change characteristics of the logarithmic function, the shut-in temperature value when the temperature change rate with time is close to zero is selected from the shut-in temperature curve as the shut-in steady-state temperature.

[0071] In the present application, the shut-in steady-state temperature and the open steady-state temperature can be determined according to the change rules of the shut-in temperature and the open temperature of each sampling point of the perforated layer, and in combination with the logarithmic function relationship. According to the method, when the working system of the water injection well changes, the DTS logging curve changes with time following the change characteristics of the logarithmic function, and when the temperature reaches a steady state, the temperature change rate with time is basically close to zero. The method is used to determine the open temperature curve and the shut-in steady-state temperature curve under different working systems, thereby providing accurate input data for DTS layered flow inversion calculation.

[0072] The present application also provides a layered flow calculation system based on DTS logging data, which is used to implement the layered flow calculation method described above, and as shown in Figure 2 The layered flow calculation system comprises the following modules:

[0073] A temperature curve drawing module is used to collect the shut-in temperature and the open temperature of each sampling point of each layer of the formation, and draw a shut-in temperature curve and an open temperature curve according to the shut-in temperature and the open temperature, wherein the formation comprises a perforated layer and a non-perforated layer.

[0074] A pure temperature difference calculation module is used to obtain the temperature difference of the perforated layer and the temperature difference of the non-perforated layer, and calculate the difference between the temperature difference of the perforated layer and the temperature difference of the non-perforated layer as the pure temperature difference.

[0075] A sampling point flow calculation module is used to calculate the flow of each sampling point of the perforated layer according to the pure temperature difference.

[0076] A layered flow calculation module is used to calculate the flow of each layer of the formation according to the number of sampling points of the perforated layer and the flow of each sampling point.

[0077] Further, the pure temperature difference calculation module comprises an open steady-state temperature selection module, which is used to select the open temperature value when the temperature change rate with time is zero from the open temperature curve of the perforated layer as the open steady-state temperature based on the change characteristics of the logarithmic function.

[0078] Furthermore, the pure temperature difference calculation module includes a shut-in steady-state temperature selection module, which is used to select the shut-in temperature value when the rate of temperature change with time is close to zero from the shut-in temperature curve based on the logarithmic function change characteristics.

[0079] Furthermore, the pure temperature difference calculation module includes a non-perforated layer steady-state temperature selection module, which is used to calculate the average value of the well opening temperature at each sampling point in the non-perforated layer as the well opening steady-state temperature of the non-perforated layer.

[0080] This invention presents a method and process for calculating the stratified flow rate of water injection wells, and a corresponding system for implementing the method, such as... Figure 9 As shown, it includes: (1) determination of the shut-in temperature steady-state curve; (2) determination of the open-end temperature steady-state curve; (3) determination of the pure temperature difference curve; (4) determination of the flow rate value at each sampling point in the perforation section; and (5) calculation of the stratified flow rate value.

[0081] Example

[0082] To make the objectives, technical solutions, and advantages of the present invention clearer, the specific embodiments of the present invention will be further described in detail below with reference to the accompanying drawings. Here, the illustrative embodiments and descriptions of the present invention are used to explain the present invention, but are not intended to limit the present invention.

[0083] like Figure 5 The image shows fiber optic DTS logging data for a water injection well. The well was tested using DTS on October 13, 2020, and had two operating modes: a daily injection rate of 30 m³ / s. 3 60m 3 The well has two perforated sections. On October 7, 2020, a conventional water absorption profile was tested, showing 16.2% water absorption in the upper section and 83.8% water absorption in the lower section.

[0084] like Figure 9 As shown, steps 101 and 102 are as follows: based on the time variation of shut-in temperature and open temperature at each sampling point of the perforation layer, the near-steady-state shut-in temperature and steady-state open temperature are determined by combining the logarithmic function relationship.

[0085] like Figure 6 As shown, the daily water injection volume is 30m³. 3 At that time, the water injection temperature of the perforated layer basically reached a steady state; the daily water injection volume was 60m³. 3 At that time, the monitoring time was too short, and the temperature had not reached a steady state, requiring steady-state correction. According to the logarithmic curve pattern, among which... Figure 6 The location indicated by the black arrow represents the predicted steady-state temperature. This method was used to perform steady-state correction on each sampling point in the perforation section and adjacent points in the upper part of the perforation layer.

[0086] Step 103: Use the temperature difference between the perforated section and the non-perforated section as the pure temperature difference. The non-perforated layer is selected from the layer near the perforated layer. The specific formula is as follows:

[0087] The expression for the temperature difference in the perforated layer is:

[0088] ΔT 射孔 =T 射孔关 -T 射孔开 ;

[0089] In the formula, △T 射孔 Expressed as temperature difference in the perforation layer, T 射孔关 The shut-in steady-state temperature (T) of the perforated layer is expressed as T. 射孔开 This represents the steady-state temperature at the start of the well in the perforated zone.

[0090] The expression for the temperature difference in the non-perforated layer is:

[0091] ΔT 非射孔 =T 非射孔关 -T 非射孔开 ;

[0092] In the formula, △T 非射孔 Represented as temperature difference in the non-perforated layer, T 非射孔关 Represented as the shut-in steady-state temperature (T) of the non-perforated layer. 非射孔开 This represents the steady-state temperature at the opening of the non-perforated layer. The average value of the temperature difference in the non-perforated layer can be used in the calculation.

[0093] The expression for the pure temperature difference of the perforated layer is:

[0094] ΔT=ΔT 射孔 -ΔT 非射孔 ;

[0095] In the formula, ΔT represents the pure temperature difference of the perforation layer.

[0096] like Figure 7 The figure shows the pure temperature difference values ​​of each sampling point in the perforated section of the well, calculated according to the calculation method described in this embodiment. Among them, the measurement points 1519.605m, 1520.102m, 1520.599m, and 1521.593m are the pure temperature differences of each sampling point in the upper layer, and the remaining measurement points are the pure temperature differences of each sampling point in the lower layer.

[0097] Step 104: Determine the flow rate values ​​at each sampling point in the perforated section. Based on the characteristics of the injection well, the greater the water absorption of the formation, the slower the well shut-in temperature recovery and the larger the pure temperature difference; conversely, the smaller the water absorption of the formation, the faster the well shut-in temperature recovery and the smaller the pure temperature difference. The formula for calculating the flow rate at each sampling point in the perforated layer is as follows:

[0098]

[0099] In the formula, Q i Q represents the daily injection volume of the i-th sampling point of the perforated layer, Q represents the daily injection volume of a single well, and ΔT i Q represents the pure temperature difference of the i-th sampling point of the perforated layer, and ∑ΔT represents the sum of the pure temperature differences of all sampling points of the perforated layer.

[0100] As Figure 8 shown, it is the injection volume split value of each sampling point of the perforated layer calculated according to the calculation method of the present application in the present embodiment. Among them, the measuring points 1519.6m, 1520.1m, 1520.6m and 1521.6m are the injection volume of each sampling point of the upper layer, and the rest of the measuring points are the injection volume of each sampling point of the lower layer.

[0101] Step 105: Layered flow value calculation. According to the number of sampling points corresponding to each perforated layer, the flow values corresponding to the sampling points are accumulated to calculate the layered flow, and the calculation is completed.

[0102] As Figure 10 shown, it is the layered flow calculation result of the well, in which the injection volume of the upper layer accounts for 14.7%, and the injection volume of the lower layer accounts for 85.3%, which is basically consistent with the interpretation result of the water injection profile, verifying the accuracy of the method.

[0103] In order to achieve the above-mentioned purpose, the main technical means adopted in the present application is to clearly, completely and accurately describe the essential content of the invention, and the degree of disclosure is that the ordinary skilled in the art can understand and implement it.

Claims

1. A method for calculating layered flow rate based on DTS logging data, characterized in that, Includes the following steps: The shut-in temperature and open temperature of each stratum sampling point are collected, and shut-in temperature curves and open temperature curves are plotted based on the shut-in temperature and open temperature. The strata include perforated layers and non-perforated layers. Obtain the temperature difference between the perforated layer and the non-perforated layer, and calculate the difference between the temperature difference between the perforated layer and the non-perforated layer as the pure temperature difference; Calculate the flow rate at each sampling point in the perforation layer based on the pure temperature difference; Calculate the flow rate of each formation layer based on the number of sampling points in the perforated layer and the flow rate at each sampling point; The non-perforated layer is selected from the layer above the perforated layer; The expression for the temperature difference in the perforated layer is: ； In the formula, △T 射孔 Expressed as temperature difference in the perforation layer, T 射孔关 The shut-in steady-state temperature (T) of the perforated layer is expressed as T. 射孔开 Represented as the wellhead steady-state temperature of the perforated layer; The calculation expression for the flow rate at each sampling point of the perforation layer based on the pure temperature difference is as follows: ； In the formula, Q i Let T represent the daily water injection rate at the i-th sampling point in the perforated layer, Q represent the daily water injection rate of a single well, and ΔT represent the daily water injection rate of a single well. i Let represent the pure temperature difference at the i-th sampling point of the perforation layer. It is expressed as the sum of the pure temperature differences at all sampling points in the perforation layer; The expression for the temperature difference in the non-perforated layer is: ； In the formula, △T 非射孔 Represented as temperature difference in the non-perforated layer, T 非射孔关 The shut-in steady-state temperature (T) of the non-perforated layer is expressed as T. 非射孔开 This represents the steady-state temperature at the opening of the non-perforated layer.

2. The method for calculating layered flow rate based on DTS logging data according to claim 1, characterized in that, The selection of the wellbore steady-state temperature of the perforated layer includes: Based on the logarithmic function variation characteristics, the well temperature at which the rate of temperature change with time is zero is selected from the well opening temperature curve of the perforated layer as the well opening steady-state temperature.

3. The method for calculating layered flow rate based on DTS logging data according to claim 1, characterized in that, The selection of the wellbore steady-state temperature of the non-perforated layer includes: The average well opening temperature of each sampling point in the non-perforated layer is calculated as the well opening steady-state temperature of the non-perforated layer.

4. The method for calculating layered flow rate based on DTS logging data according to claim 1, characterized in that, After plotting the shut-in temperature curve based on the shut-in temperature, the method further includes: Based on the logarithmic function variation characteristics, the shut-in temperature value at which the rate of temperature change with time is zero is selected from the shut-in temperature curve as the shut-in steady-state temperature.

5. A layered flow rate calculation system based on DTS logging data, characterized in that, The hierarchical flow calculation method based on any one of claims 1-4 includes: The temperature curve plotting module is used to collect the shut-in temperature and open temperature of each layer of the formation sampling point, and plot the shut-in temperature curve and open temperature curve based on the shut-in temperature and open temperature. The formation includes perforated layers and non-perforated layers. The pure temperature difference calculation module is used to obtain the temperature difference between the perforated layer and the non-perforated layer, and calculate the difference between the temperature difference between the perforated layer and the non-perforated layer as the pure temperature difference. The sampling point flow rate calculation module is used to calculate the flow rate at each sampling point in the perforation layer based on the pure temperature difference. The stratified flow calculation module is used to calculate the flow of each stratum based on the number of sampling points in the perforated layer and the flow rate at each sampling point.

6. The layered flow calculation system based on DTS logging data according to claim 5, characterized in that, The pure temperature difference calculation module includes a well-start steady-state temperature selection module. The well-start steady-state temperature selection module is used to select the well-start temperature value when the rate of temperature change with time is zero from the well-start temperature curve of the perforated layer based on the logarithmic function change characteristics.

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