Coiled tubing mechanical control type double-seal dragging fracturing equipment and fracturing method

Abstract

The invention relates to the technical field of oil field reservoir transformation, in particular to coiled tubing mechanical control type double-seal dragging fracturing equipment and a fracturing method. The method comprises the following steps: by taking a reference layer section as a reference, analyzing the temperature change of each sampling position in a target layer section in a target period to obtain a plurality of temperature difference data, and carrying out local peak point detection on the temperature difference data to determine a plurality of temperature difference local peak data; the peak height, the peak width and the fracturing balance time consumption of each piece of temperature difference local peak data are analyzed in the multiple pieces of temperature difference local peak data, the probability that each piece of temperature difference local peak data indicates the main fracture is determined, and then the target sampling position indicating the main fracture is recognized according to the probability; and finally, according to the temperature changes of the multiple target sampling positions and the number of the multiple target sampling positions, whether fracturing operation of the target layer section is stopped or not is determined. According to the device and the method, a fracturing operation detection result with high timeliness can be output, unnecessary loss of fracturing fluid is avoided, and the exploitation cost of a low-permeability tight reservoir is reduced.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of oilfield reservoir reconstruction, and in particular to a coiled tubing mechanical control type double-seal drag fracturing device and a fracturing method. BACKGROUND

[0002] Most of the peripheral oilfields in Daqing are low-permeability tight reservoirs, which have the characteristics of low porosity, low permeability, low abundance, and multiple thin layers (vertically), and good production increase effect can be achieved through large-scale volume fracturing, but the production declines rapidly after fracturing. Currently, double-seal single-card drag fracturing technology is mainly used for repeated fracturing of horizontal wells.

[0003] It is found in application that due to the stress distribution of low-permeability tight reservoirs and the mutual interference of fracturing fracture networks, the commonly used monitoring methods such as tracer, microseismic, and pressure curve analysis have a lag in sensing the expansion of multiple clusters of fractures during fracturing, which easily causes excessive injection of fracturing fluid, resulting in unnecessary consumption of fracturing fluid and increased production cost.

[0004] That is, the monitoring timeliness of the fracturing effect of low-permeability tight reservoirs in the prior art is low. SUMMARY

[0005] The present application aims to provide a coiled tubing mechanical control type double-seal drag fracturing device and a fracturing method, which solve the technical problem of low monitoring timeliness of the fracturing effect of low-permeability tight reservoirs in the prior art.

[0006] In a first aspect, an embodiment of the present application provides a coiled tubing mechanical control type double-seal drag fracturing method, which comprises:

[0007] The temperature changes of each sampling position in the target layer section in the target period are analyzed with a reference layer section as a reference to obtain a plurality of temperature difference data, wherein the reference layer section is adjacent to the target layer section and is in the same depth interval, and the plurality of temperature difference data correspond one-to-one to a plurality of sampling positions in the target layer section;

[0008] Local peak points of the plurality of temperature difference data are detected to determine a plurality of temperature difference local peak data;

[0009] The peak characteristic information of each temperature difference local peak data is analyzed in the plurality of temperature difference local peak data to obtain a main fracture index of each temperature difference local peak data, wherein the peak characteristic information includes a first characteristic indicating the peak height of the corresponding temperature difference local peak data, a second characteristic indicating the peak width of the corresponding temperature difference local peak data, and a third characteristic indicating the fracturing balance time of the corresponding temperature difference local peak data, and the main fracture index is used to represent the probability of the corresponding temperature difference local peak data indicating a main fracture;

[0010] identifying, from all the sampling positions included in the target interval, target sampling positions indicating the main fractures based on the main fracture indexes of each temperature difference local peak data;

[0011] determining a target operation result based on the temperature changes of the multiple target sampling positions in the target period and the number of the multiple target sampling positions, wherein the target operation result is used to indicate whether the fracturing operation of the target interval is stopped.

[0012] In some embodiments, the step of analyzing the temperature changes of each sampling position in the target interval in the target period to obtain multiple temperature difference data by taking the reference interval as a reference includes:

[0013] calculating an average value of the temperature values of all the sampling positions in the reference interval at the end time of the target period to obtain a reference temperature;

[0014] analyzing the differences between the average temperature values of the multiple sampling positions in the target interval and the reference temperature in the target period respectively to obtain multiple temperature difference data.

[0015] In some embodiments, the step of obtaining the third feature of each temperature difference local peak data in the multiple temperature difference local peak data includes:

[0016] In the multiple temperature difference local peak data, analyzing the temperature changes of the sampling position indicated by each temperature difference local peak data after each temperature sampling time in the target period to determine multiple fracturing balance indexes associated with each temperature difference local peak data, wherein the multiple fracturing balance indexes associated with each temperature difference local peak data correspond to the multiple temperature sampling times in the target period one by one;

[0017] In the multiple fracturing balance indexes associated with each temperature difference local peak data, determining the temperature sampling time corresponding to the maximum fracturing balance index as a corresponding fracturing balance time to obtain the fracturing balance time corresponding to each temperature difference local peak data;

[0018] determining the third feature of each temperature difference local peak data based on a first time difference between the fracturing balance time corresponding to each temperature difference local peak data and the start time of the target period.

[0019] In some embodiments, in the multiple temperature difference local peak data, the step of analyzing the temperature changes of the sampling position indicated by each temperature difference local peak data after each temperature sampling time in the target period to determine multiple fracturing balance indexes associated with each temperature difference local peak data includes:

[0020] obtaining a plurality of backward temperature sequences associated with each of the temperature difference local peak data, wherein the plurality of backward temperature sequences correspond to a plurality of temperature sampling time points in the target period one by one, and the backward temperature sequence comprises a plurality of temperature values collected from the corresponding temperature sampling time point to the end time point of the target period;

[0021] In the plurality of temperature difference local peak data, the dispersion degree of each backward temperature sequence associated with each temperature difference local peak data is analyzed to obtain a plurality of temperature dispersion coefficients associated with each temperature difference local peak data;

[0022] In the plurality of temperature sampling time points in the target period, a second time difference between each temperature sampling time point and the end time point of the target period is analyzed to determine a time domain coefficient of each temperature sampling time point, wherein the time domain coefficient and the corresponding second time difference are in a negative correlation relationship;

[0023] In the plurality of temperature dispersion coefficients associated with each temperature difference local peak data, each fracture balance index associated with each temperature difference local peak data is determined according to each temperature dispersion coefficient associated with each temperature difference local peak data and the corresponding time domain coefficient.

[0024] In some embodiments, the main fracture index has a positive correlation trend with the first feature, the main fracture index has a positive correlation trend with the second feature, and the main fracture index has a positive correlation trend with the third feature.

[0025] In some embodiments, based on the main fracture index of each temperature difference local peak data, the step of identifying a target sampling position indicating a main fracture in all sampling positions included in the target interval comprises:

[0026] Calculating the average value of the main fracture index of the plurality of temperature difference local peak data to obtain an index average value;

[0027] In the plurality of temperature difference local peak data, the sampling position indicated by the temperature difference local peak data with a main fracture index greater than the index average value is determined as the target sampling position.

[0028] In some embodiments, according to the temperature change of the plurality of target sampling positions in the target period and the number of the plurality of target sampling positions, the step of determining a target operation result comprises:

[0029] Analyzing the temperature rise degree of each target sampling position after the corresponding fracture balance time to obtain a fracture saturation index of each target sampling position;

[0030] According to the fracture balance index corresponding to each target sampling position, a calculation weight of each target sampling position is determined;

[0031] Based on the calculation weight of each target sampling location, the crack saturation index of multiple target sampling locations is weighted and calculated to obtain the pumping saturation index;

[0032] The target operation result is determined based on the pump saturation index and the number of multiple target sampling locations.

[0033] In some embodiments, the step of determining the calculation weight of each target sampling location based on the fracturing balance index corresponding to each target sampling location includes:

[0034] Calculate the sum of the fracturing balance indices corresponding to multiple target sampling locations to obtain the cumulative index value;

[0035] Calculate the ratio of the fracturing balance index to the cumulative index value corresponding to each target sampling location to obtain the calculation weight of each target sampling location.

[0036] In some embodiments, the output probability of the target operation result indicating the cessation of fracturing operations in the target segment is positively correlated with the number of multiple target sampling locations, and the output probability of the target operation result indicating the cessation of fracturing operations in the target segment is positively correlated with the pump saturation index.

[0037] Secondly, another embodiment of the present invention provides a coiled tubing mechanically controlled dual-seal drag fracturing device, the device comprising:

[0038] The data acquisition module is used to analyze the temperature changes at each sampling location in the target layer within the target period, with the reference layer as a reference, and obtain multiple temperature difference data. The reference layer and the target layer are adjacent and in the same depth range, and the multiple temperature difference data correspond one-to-one with multiple sampling locations in the target layer.

[0039] The peak detection module is used to perform local peak detection on the multiple temperature difference data to determine the multiple local peak data of temperature difference.

[0040] The feature analysis module is used to analyze the peak feature information of each local temperature difference peak data in the multiple local temperature difference peak data to obtain the main fracture index of each local temperature difference peak data. The peak feature information includes a first feature indicating the peak height of the corresponding local temperature difference peak data, a second feature indicating the peak width of the corresponding local temperature difference peak data, and a third feature indicating the fracturing balance time of the corresponding local temperature difference peak data. The main fracture index is used to characterize the probability that the corresponding local temperature difference peak data indicates a main fracture.

[0041] The main fracture identification module is used to identify the target sampling location indicating the main fracture among all sampling locations included in the target layer based on the main fracture index of each local temperature difference peak data.

[0042] The operation result detection module is configured to determine a target operation result according to temperature changes of the plurality of target sampling positions in the target period and the number of the plurality of target sampling positions, wherein the target operation result is used to indicate whether the fracturing operation of the target interval is stopped.

[0043] In a third aspect, a further embodiment of the present application provides an electronic device, including a processor, a memory, and a computer program stored in the memory and executable on the processor, wherein the computer program, when executed by the processor, implements the steps of the method of the first aspect.

[0044] In a fourth aspect, a further embodiment of the present application provides a computer-readable storage medium, wherein the computer-readable storage medium stores a computer program, and the computer program, when executed by a processor, implements the steps of the method of the first aspect.

[0045] The present application has the following advantages:

[0046] The present application uses the adjacent intervals of the same depth interval as a reference to analyze the temperature changes of each part of the target interval in the target period, to obtain a plurality of temperature difference data for accurately quantifying the temperature change amplitude of each part of the target interval, and then identifies a plurality of temperature difference local peak data corresponding to the crack region from the plurality of temperature difference data by means of local peak detection, and then further analyzes the peak height, peak width and time consumption of each temperature difference local peak data to reach fracturing balance, so as to determine the probability of the sampling position corresponding to the main crack region indicated by each temperature difference local peak data, and accordingly identify a plurality of target sampling positions corresponding to the main crack region from the plurality of sampling positions corresponding to the crack region, and determine whether the fracturing operation of the target interval is stopped by comprehensively analyzing the temperature changes of each target sampling position and the total number of the plurality of target sampling positions, so as to realize the timely monitoring of the fracturing effect of the low-permeability tight reservoir, and in particular, in the case that the fracturing effect of the target interval meets the expectation, the continuous injection of the fracturing fluid is stopped in time, unnecessary consumption of the fracturing fluid is avoided, and the exploitation cost of the low-permeability tight reservoir is reduced. BRIEF DESCRIPTION OF DRAWINGS

[0047] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, and the advantages thereof, the drawings needed to be used in the embodiments or prior art description will be briefly introduced as follows. Obviously, the drawings in the following description are only some embodiments of the present application, and for those skilled in the art, other drawings can also be obtained without creative labor based on these drawings.

[0048] Figure 1 is a structural schematic diagram of a coiled tubing mechanical control type double-seal drag fracturing construction equipment provided by an embodiment of the present application.

[0049] Figure 2 This is a schematic flowchart of a coiled tubing mechanically controlled double-seal drag fracturing method provided in an embodiment of the present invention;

[0050] Figure 3 This is a schematic diagram of the structure of a coiled tubing mechanically controlled double-seal drag fracturing device provided in an embodiment of the present invention;

[0051] Figure 4 This is a schematic diagram of an electronic device provided in an embodiment of the present invention. Detailed Implementation

[0052] To further illustrate the technical means and effects adopted by the present invention to achieve its intended purpose, the following, in conjunction with the accompanying drawings and preferred embodiments, details the specific implementation, structure, features, and effects of a coiled tubing mechanically controlled double-seal drag fracturing device and fracturing method proposed according to the present invention. In the following description, different "one embodiment" or "another embodiment" do not necessarily refer to the same embodiment. Furthermore, specific features, structures, or characteristics in one or more embodiments can be combined in any suitable form.

[0053] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains.

[0054] The following description, in conjunction with the accompanying drawings, details the specific scheme of the coiled tubing mechanically controlled double-seal drag fracturing equipment and fracturing method provided by the present invention.

[0055] For low-permeability tight reservoirs, if the dual-seal drag technology is used for staged fracturing, the corresponding packers need to be set and unsealed multiple times. After a certain stage of fracturing, a pressure difference will appear between the upper and lower parts of the packer, which will interfere with the unsealing operation of the packer. In severe cases, it may even lead to damage to the device and cause the construction to be interrupted.

[0056] Based on this, embodiments of the present invention provide a coiled tubing mechanically controlled double-seal drag fracturing construction device, such as... Figure 1 As shown, Figure 1 Number 1 indicates continuous tubing, number 2 indicates safety joint, number 3 indicates pressure relief valve, number 4 indicates hydraulic anchor, number 5 indicates top packer, number 6 indicates sandblaster, number 7 indicates balance valve, number 8 indicates bottom packer, and number 9 indicates positioning elastic stabilizer.

[0057] The upper and lower ends of the safety joint are respectively fixed by thread connection with the coiled tubing and the upper end of the pressure relief valve, the upper and lower ends of the hydraulic anchor are respectively fixed by thread connection with the lower end of the pressure relief valve and the upper end of the top packer, the upper and lower ends of the sandblaster are respectively fixed by thread connection with the lower end of the top packer and the upper end of the balance valve, and the upper and lower ends of the top packer are respectively fixed by thread connection with the lower end of the balance valve and the upper end of the positioning elastic centralizer.

[0058] The top packer and the bottom packer are combined and used in linkage, and are both mechanically set and released by the lifting and lowering pipe column.

[0059] The top packer is provided with the pressure relief valve with pressure relief function at the upper end, and the opening and closing of the pressure relief valve is controlled by the mechanical mode of lifting and lowering the pipe column.

[0060] The bottom packer is provided with the balance valve with pressure relief function at the upper end, and the opening and closing of the balance valve is controlled by the mechanical mode of lifting and lowering the pipe column.

[0061] When the above-mentioned coiled tubing mechanically controlled double sealing drag fracturing construction equipment is applied, the coiled tubing needs to be lowered to the predetermined position of the low-permeability tight reservoir horizontal well in the oil field, the positioning elastic centralizer is used to realize accurate positioning during the lowering process of the pipe column, then the pipe column is lifted and lowered to complete the setting of the bottom packer and the top packer in sequence, the pressure relief valve and the balance valve are closed, then the fracturing fluid is pumped through the coiled tubing by the ground pump truck, the hydraulic anchor is anchored to the inner wall of the casing under the action of the casing pressure difference, the sandblaster is used as a communication channel with the formation to check the sealing of the top packer and the bottom packer.

[0062] After that, the layer section of the low-permeability tight reservoir horizontal well between the top packer and the bottom packer is used as the target layer section of the fracturing operation, and there are multiple cluster fractures in the target layer section, the fracturing fluid carrying the proppant is sprayed out of the sandblaster nozzle and into the target layer section during the fracturing operation, and the multiple cluster fractures in the target layer section are subjected to fracturing construction.

[0063] After the fracturing construction is completed, the pipe column is lifted, the pressure relief valve is opened, the communication channel of the casing is established, the casing pressure is balanced, the hydraulic anchor is not anchored to the casing, the pipe column is continuously lifted, the top packer is released, the balance valve 7 is opened, the casing pressure is balanced again, the bottom packer is released, the pipe column is dragged and lifted to the next layer section (which can be understood as a new target layer section) of the horizontal well fracturing reconstruction through the accurate positioning of the positioning elastic centralizer, and the above-mentioned process is repeated until all layer sections of the low-permeability tight horizontal well (also referred to as low-permeability tight reservoir) are completed fracturing reconstruction.

[0064] In the above-mentioned process, the balance valve is used to balance the pressure difference above and below the packer after the packer completes the fracturing of a certain layer section, to ensure that the release operation of the subsequent packer is successfully performed, and to ensure the continuity of the construction of the low-permeability tight horizontal well.

[0065] But it is pointed out that, during the fracturing construction of the multiple cluster fractures of the target interval, the fracturing construction effect of the multiple cluster fractures of the target interval is difficult to be accurately monitored based on the tracer, microseismic, pressure curve analysis and other commonly used monitoring methods of oil wells, and unnecessary waste of fracturing fluid is easily caused.

[0066] Based on this, the application further provides a coiled tubing mechanically controlled double-seal drag fracturing method to adapt to the aforementioned coiled tubing mechanically controlled double-seal drag fracturing construction equipment, and to reduce unnecessary consumption of fracturing fluid as much as possible, specifically as shown in the figure, the method comprises: Figure 2 As shown in the figure, the method comprises:

[0067] Step S1, taking the reference interval as a reference, analyze the temperature changes of each sampling position in the target interval in the target period to obtain a plurality of temperature difference data.

[0068] Wherein, the reference interval is adjacent to the target interval and is in the same depth interval, and the plurality of temperature difference data is one-to-one corresponding to the plurality of sampling positions in the target interval.

[0069] The above-mentioned target interval can be understood as the interval (i.e. the aforementioned target interval) of the multiple intervals (different intervals are in different depth intervals) included in the low-permeability tight horizontal well which is being fractured.

[0070] In application, if the intersection position of the low-permeability tight horizontal well and the vertical well is set as the origin in the horizontal direction, the distance between each position and the origin in the horizontal direction is defined as the coordinate value of each position in the horizontal direction, then the coordinate value interval corresponding to the target interval is , and the coordinate value interval corresponding to the reference interval is .

[0071] In the application, by installing a distributed optical fiber system (DTS) outside the casing, the temperature data of each position in the target interval and each position in the reference interval are sensed, the distributed optical fiber system uniformly arranges a plurality of sampling positions along the horizontal direction, the interval between adjacent sampling positions is 0.25 meters, the distributed optical fiber system performs periodic sampling, and the time interval between adjacent two sampling operations is 30 seconds.

[0072] In practical application, other devices with temperature detection function can also be selected to periodically collect the temperature data of each position in the target interval and each position in the reference interval.

[0073] In the application, the multiple cluster fractures of the target interval are intermittently fractured, the fracturing effect of the target interval is detected once after each set time (i.e. one construction period), and whether to continue the next construction is determined according to the detection result, and the above-mentioned target period can be understood as any one of the plurality of construction periods associated with the target interval.

[0074] The length of the construction period can be between 2 minutes and 15 minutes, the shorter the construction period, the stronger the timeliness of monitoring the fracturing construction effect of the target interval, and in the application, the length of the construction period is set to 5 minutes based on experience.

[0075] Specifically, the temperature changes of each sampling position in the target interval in the target period are analyzed with the reference interval as a reference to obtain a plurality of temperature difference data, including:

[0076] At the end of the target period, the average value of the temperature values of all sampling positions in the reference interval is calculated to obtain a reference temperature;

[0077] In the target period, the differences between the temperature average values of the plurality of sampling positions in the target interval and the reference temperature are analyzed respectively to obtain a plurality of temperature difference data.

[0078] In the fracturing construction process of the multiple cluster fractures in the target interval, the fracturing fluid at low temperature (compared to the original temperature of the reservoir) continuously enters the fractures and is filtered into the reservoir, and the flow process is accompanied by heat conduction and heat convection effects, which will continuously cool the wellbore, fractures and surrounding formations, therefore, the area where the fractures in the target interval are located will be in a heat dissipation state.

[0079] In the above setting, the reference temperature is obtained to dynamically determine the appropriate temperature threshold according to the actual temperature condition of the target interval in the target period, which can effectively ensure the accuracy of the temperature difference data calculated subsequently.

[0080] And analyzing the differences between the temperature average values of the sampling positions and the reference temperature can effectively suppress the interference of extreme noise, accurately quantify the temperature drop amplitude of each sampling position in the target period based on the overall temperature trend of each sampling position, and further ensure the accuracy of the calculated temperature difference data.

[0081] In the application, the average value of the plurality of temperature values of each sampling position in the target period is determined as the corresponding temperature average value, and the difference between the reference temperature and the temperature average value of each sampling position is determined as the corresponding temperature difference data.

[0082] Step S2, local peak point detection is performed on the plurality of temperature difference data to determine a plurality of temperature difference local peak data.

[0083] As mentioned above, the greater the value of the temperature difference data, the more significant the temperature drop amplitude of the corresponding sampling position, that is, the greater the probability that the corresponding sampling position indicates the fracture position / fracture area.

[0084] The present invention, through the measure of local peak detection, can initially identify sampling locations with a high probability of indicating crack areas from multiple sampling locations included in the target layer, so as to carry out targeted analysis and processing in the future. This can reduce the amount of data to be processed in the future while avoiding interference from sampling locations that are not crack locations, and improve the overall processing efficiency of the solution.

[0085] The aforementioned local peak detection aims to identify the temperature difference data with corresponding local maxima (the value of the corresponding temperature difference data is greater than the value of the previous temperature difference data and greater than the value of the next temperature difference data) from multiple temperature difference data (arranged in order of horizontal coordinate values) and determine them as local temperature difference peak data.

[0086] In one example, the present invention uses the AMPD peak finding algorithm to complete the above-mentioned local peak detection operation.

[0087] Step S3: Analyze the peak characteristic information of each temperature difference local peak data in the multiple temperature difference local peak data to obtain the main crack index of each temperature difference local peak data.

[0088] Among them, the peak feature information includes a first feature indicating the peak height of the corresponding local temperature difference peak data, a second feature indicating the peak width of the corresponding local temperature difference peak data, and a third feature indicating the fracturing balance time of the corresponding local temperature difference peak data. The main fracture index is used to characterize the probability that the corresponding local temperature difference peak data indicates a main fracture (a large-volume fracture designed to provide an efficient channel for oil and gas to flow from the far end of the reservoir to the wellbore).

[0089] It should be noted that in the fracturing operation, the concept opposite to the main fracture is the secondary fracture (small-volume fracture, which usually cannot provide a channel for oil and gas to flow from the far end of the reservoir to the wellbore, or can only provide an inefficient channel for oil and gas to flow from the far end of the reservoir to the wellbore), such as branch fractures and micro fractures.

[0090] The primary fracture can hold more fracturing fluid (compared to the secondary fracture) during fracturing operations, resulting in a more significant temperature drop and a longer duration of the temperature drop process.

[0091] The value of the first feature mentioned above is specifically the value of the local peak data of the corresponding temperature difference, and the value of the second feature mentioned above is specifically the half-width at half-maximum of the local peak data of the corresponding temperature difference (referring to the length of the line segment formed by extending to both sides and first intersecting with the data curve in the data curve corresponding to multiple temperature difference data).

[0092] In the present application, the fracturing balance time is understood as the time from the start time of the target period to the temperature balance (slow temperature drop, remain unchanged or slowly rising trend) after the corresponding fracture is fully filled with fracturing fluid.

[0093] The greater the main fracture index, the higher the probability that the corresponding temperature difference local peak data indicates the main fracture.

[0094] It should be understood that the main fracture index is positively correlated with the first feature, the main fracture index is positively correlated with the second feature, and the main fracture index is positively correlated with the third feature.

[0095] In the present application, the positive correlation trend is understood as: two values associated with each other, as one of the values increases, the probability of the other value increasing also increases accordingly.

[0096] The higher the value of the temperature difference local peak data, the greater the temperature drop at the corresponding sampling position, and the more fracturing fluid the corresponding sampling position contacts, the higher the probability that the corresponding sampling position indicates the main fracture of the fracturing operation.

[0097] The greater the half-width of the temperature difference local peak data, the more persistent the temperature drop process at the corresponding sampling position, and the more fracturing fluid the corresponding sampling position contacts, so the probability that the corresponding sampling position indicates the main fracture of the fracturing operation is also higher.

[0098] The longer the fracturing balance time, the more time the corresponding sampling position takes to change from temperature shock to temperature balance, and the greater the volume of the fracture region indicated by the corresponding sampling position, so the probability that the corresponding sampling position indicates the main fracture of the fracturing operation is also higher.

[0099] In one example, the first feature, the second feature and the third feature of each temperature difference local peak data can be processed based on the trained neural network model to obtain the main fracture index of each temperature difference local peak data.

[0100] In another example, the first feature, the second feature and the third feature of each temperature difference local peak data can also be processed using the Topsis advantage and disadvantage solution distance algorithm to obtain the main fracture index of each temperature difference local peak data.

[0101] Specifically, the third feature of each temperature difference local peak data in the plurality of temperature difference local peak data is obtained by:

[0102] In the multiple temperature difference local peak data, a temperature change of the sampling position indicated by each temperature difference local peak data after each temperature sampling time in the target period is analyzed, and multiple fracturing balance indexes associated with each temperature difference local peak data are determined, wherein the multiple fracturing balance indexes associated with each temperature difference local peak data correspond to the multiple temperature sampling times in the target period one by one.

[0103] In the multiple fracturing balance indexes associated with each temperature difference local peak data, a temperature sampling time corresponding to the maximum fracturing balance index is determined as a corresponding fracturing balance time, so as to obtain a fracturing balance time corresponding to each temperature difference local peak data.

[0104] According to a first time difference between the fracturing balance time corresponding to each temperature difference local peak data and a starting time of the target period, a third feature of each temperature difference local peak data is determined.

[0105] The fracturing balance index is used to indicate a confidence degree of determining the corresponding temperature sampling time as the fracturing balance time (the time of reaching temperature balance) of the corresponding sampling position. The higher the fracturing balance index is, the more credible the corresponding temperature sampling time is determined as the fracturing balance time of the corresponding sampling position.

[0106] In the multiple temperature difference local peak data, a temperature change of the sampling position indicated by each temperature difference local peak data after each temperature sampling time in the target period is analyzed, and multiple fracturing balance indexes associated with each temperature difference local peak data are determined, wherein the multiple fracturing balance indexes associated with each temperature difference local peak data correspond to the multiple temperature sampling times in the target period one by one.

[0107] Multiple backward temperature sequences associated with each temperature difference local peak data are obtained, wherein the multiple backward temperature sequences correspond to the multiple temperature sampling times in the target period one by one, and the backward temperature sequence comprises multiple temperature values collected from the corresponding temperature sampling time to an ending time of the target period for the corresponding sampling position;

[0108] In the multiple temperature difference local peak data, a temperature change of the sampling position indicated by each temperature difference local peak data after each temperature sampling time in the target period is analyzed, and multiple fracturing balance indexes associated with each temperature difference local peak data are determined, wherein the multiple fracturing balance indexes associated with each temperature difference local peak data correspond to the multiple temperature sampling times in the target period one by one.

[0109] In the multiple temperature sampling times in the target period, a second time difference between each temperature sampling time and the ending time of the target period is analyzed, and a time domain coefficient of each temperature sampling time is determined, wherein the time domain coefficient and the corresponding second time difference are in a negative correlation relationship.

[0110] In the multiple temperature difference local peak data, a temperature change of the sampling position indicated by each temperature difference local peak data after each temperature sampling time in the target period is analyzed, and multiple fracturing balance indexes associated with each temperature difference local peak data are determined, wherein the multiple fracturing balance indexes associated with each temperature difference local peak data correspond to the multiple temperature sampling times in the target period one by one.

[0111] For the sampling locations of each indicated fracture region, the overall temperature change after the fracturing equilibrium moment is relatively stable. Therefore, the smaller the temperature dispersion coefficient, the more it indicates that the corresponding temperature sampling moment is the fracturing equilibrium moment of the corresponding sampling location.

[0112] However, it should be noted that the overall temperature change at the sampling location remains stable after the fracturing equilibrium moment, and the later the time, the more stable the overall temperature change at the sampling location. By configuring the time domain coefficient, a higher calculation coefficient can be configured for the temperature sampling moments earlier in time, which can effectively suppress the fracturing equilibrium index at temperature sampling moments after the actual fracturing equilibrium moment, so as to ensure the accuracy and reliability of the fracturing equilibrium index determined for each temperature sampling moment.

[0113] The temperature dispersion coefficient can be the standard deviation of the corresponding backward temperature sequence.

[0114] For example, the first The local temperature difference peak data is in the first Fracturing balance index at each temperature sampling time It can be represented as:

[0115] =

[0116] in, Indicates the start time of the target period. Indicates the end time of the target period. Indicates the first period within the target period At each temperature sampling time, Indicates the first The local temperature difference peak data is in the first The standard deviation of the backward temperature sequence associated with each temperature sampling time. Indicates the first The local temperature difference peak data is in the first The backward temperature sequence associated with each temperature sampling time.

[0117] It should be noted that in the above formula, if the calculated standard deviation is 0, it is determined that the fracturing balance index of the corresponding sampling location at the corresponding temperature sampling time is abnormal, and the corresponding temperature sampling time is removed from the candidate queue of the fracturing balance time of the corresponding sampling location.

[0118] Step S4: Based on the main fracture index of each local temperature difference peak data, identify the target sampling location indicating the main fracture among all sampling locations included in the target layer.

[0119] In some embodiments, the main fracture index of all the temperature difference local peak data can be normalized (scaled to the range of 0-1) and the position indicated by the temperature difference local peak data with the main fracture index (after normalization) greater than or equal to the threshold value (such as 0.7) is determined as the target sampling position.

[0120] In other embodiments, based on the main fracture index of each temperature difference local peak data, the step of identifying the target sampling position indicating the main fracture in all sampling positions included in the target interval includes:

[0121] The average value of the main fracture index of the plurality of temperature difference local peak data is calculated to obtain an index average value;

[0122] In the plurality of temperature difference local peak data, the sampling position indicated by the temperature difference local peak data with the main fracture index greater than the index average value is determined as the target sampling position.

[0123] Step S5, according to the temperature change of the plurality of target sampling positions in the target period and the number of the plurality of target sampling positions, determine the target operation result.

[0124] Wherein, the target operation result is used to indicate whether the fracturing operation of the target interval is stopped.

[0125] As mentioned earlier, the target sampling position is highly likely to indicate the position of the main fracture in the target interval, and during the fracturing operation, the number of main fractures and the temperature change will indicate the fracturing effect of the target interval. Generally speaking, the more the number of main fractures, the more the actual temperature change matches the reference temperature change (the temperature change of the main fracture of the other interval where the fracturing operation has been confirmed to be stopped), the more the fracturing operation should be stopped.

[0126] In one example, the data sequence indicating the temperature change of the plurality of target sampling positions in the target period and the number of the plurality of target sampling positions can be spliced to form model input data, and input into a pre-trained binary classification model (such as a support vector machine SVM model) to obtain a detection result output by the binary classification model, and determine whether to stop the fracturing operation of the target interval according to the detection result.

[0127] Wherein, the binary classification model is designed to output a first value or a second value according to the input data, wherein the first value represents stopping the fracturing operation of the target interval, and the second value represents continuing the fracturing operation of the target interval.

[0128] It can be seen that the present application uses the adjacent layer section of the same depth interval as a reference to analyze the temperature change of the target layer section where the fracturing operation is being carried out in the target period, so as to obtain a plurality of temperature difference data for accurately quantifying the temperature change amplitude of each part of the target layer section, then identify a plurality of temperature difference local peak data corresponding to the crack region from the plurality of temperature difference data by means of local peak point detection, and then further analyze the peak height, peak width and time consumption of each temperature difference local peak data to reach the fracturing balance, so as to determine the probability of the main crack region corresponding to the sampling position indicated by each temperature difference local peak data, and accordingly identify a plurality of target sampling positions corresponding to the main crack region from a plurality of sampling positions corresponding to the crack region, and determine whether the fracturing operation of the target layer section is stopped by comprehensively analyzing the temperature change of each target sampling position and the total number of a plurality of target sampling positions, so as to realize the timely monitoring of the fracturing effect of the low-permeability and tight reservoir, and in particular, in the case that the fracturing effect of the target layer section meets the expectation, the continuous injection of the fracturing fluid is stopped in time, unnecessary consumption of the fracturing fluid is avoided, and the exploitation cost of the low-permeability and tight reservoir is reduced.

[0129] In some embodiments, according to the temperature change of the plurality of target sampling positions in the target period and the number of the plurality of target sampling positions, the step of determining the target operation result comprises:

[0130] analyzing the temperature rise degree of each target sampling position after the corresponding fracturing balance time to obtain a crack saturation index of each target sampling position;

[0131] determining a calculation weight of each target sampling position according to the fracturing balance index corresponding to each target sampling position;

[0132] performing weighted calculation on the crack saturation index of the plurality of target sampling positions according to the calculation weight of each target sampling position to obtain a pump injection saturation index;

[0133] determining the target operation result according to the pump injection saturation index and the number of the plurality of target sampling positions, wherein the output probability of the target operation result indicating stopping the fracturing operation of the target layer section is positively correlated with the number of the plurality of target sampling positions, and the output probability of the target operation result indicating stopping the fracturing operation of the target layer section is positively correlated with the pump injection saturation index.

[0134] wherein the step of determining the calculation weight of each target sampling position according to the fracturing balance index corresponding to each target sampling position comprises:

[0135] calculating the sum of the fracturing balance indices corresponding to the plurality of target sampling positions to obtain an index cumulative value;

[0136] The ratio of the fracture balance index corresponding to each target sampling position to the cumulative value of the index is calculated to obtain the calculation weight of each target sampling position.

[0137] It should be understood that, in the case of full filling of the main fracture, it can be considered that the fracturing operation of the target interval has reached the expected operation target, and in the actual operation process, the expansion of the micro-fracture will occur during the fracturing operation process, and the full filling of the expanded micro-fracture and the secondary fracture at the end of the fracturing fluid flow line will usually cause unnecessary consumption of fracturing fluid, therefore, the measure of evaluating whether to stop the operation by comprehensively considering the temperature changes at each position of the target interval will usually output a fracturing operation detection result with low timeliness (aiming to prompt whether to stop the fracturing operation), and the present application, through the foregoing process, first identifies the target sampling position with high probability of indicating the main fracture from the sampling positions at each position of the target interval, and then judges the filling degree of the corresponding main fracture by analyzing the fracture saturation index of each target sampling position, and indirectly calculates the number of main fractures in combination with the number of target sampling positions, and comprehensively considers the above two to avoid the interference of the expanded micro-fracture and the secondary fracture at the end of the fracturing fluid flow line, and output a target operation result with high timeliness.

[0138] It should be understood that, the higher the temperature rise of the target sampling position after the corresponding fracturing balance time, the higher the filling degree of the main fracture indicated by the corresponding target sampling position, and therefore the higher the fracture saturation index of the corresponding target sampling position.

[0139] In one example, the sampling temperatures of the target sampling position after the corresponding fracturing balance time can be linearly fitted (completed by the least square method), and the slope of the fitted straight line is determined as the fracture saturation index of the corresponding target sampling position.

[0140] In this example, when the fracture saturation index of a certain target sampling position is calculated to be negative, the target operation result indicating the continuation of the fracturing operation of the target interval is directly output.

[0141] The fracture balance index indirectly reflects the volume of the corresponding main fracture, and the larger the volume of the main fracture, the higher the importance of the corresponding main fracture in the fracturing operation evaluation process, therefore, a larger calculation weight is configured to ensure the accuracy of the calculated pumping saturation index.

[0142] The pumping saturation index is used to represent the overall filling degree of the main fracture in the target interval.

[0143] In this embodiment, the pump saturation index and the number of target sampling positions can be processed by a decision model to obtain a target operation result. The decision model can also be a support vector machine (SVM) model. The description of the decision model can be referred to the description of the binary classification model (the model inputs of the two models are different, but the settings of the model output results are the same). To avoid repetition, the description will not be repeated here.

[0144] In one embodiment, the present application also provides a coiled tubing mechanically controlled double-sealing drag fracturing device, as shown in the accompanying drawings, the device 200 comprises: Figure 3

[0145] The data acquisition module 201 is configured to analyze the temperature changes of each sampling position in the target layer section in the target period with reference to a reference layer section, to obtain a plurality of temperature difference data, wherein the reference layer section is adjacent to the target layer section and is in the same depth interval, and the plurality of temperature difference data correspond to the plurality of sampling positions in the target layer section one by one.

[0146] The peak detection module 202 is configured to perform local peak detection on the plurality of temperature difference data to determine a plurality of temperature difference local peak data.

[0147] The feature analysis module 203 is configured to analyze the peak feature information of each temperature difference local peak data from the plurality of temperature difference local peak data, to obtain a main fracture index of each temperature difference local peak data, wherein the peak feature information includes a first feature indicating the peak height of the corresponding temperature difference local peak data, a second feature indicating the peak width of the corresponding temperature difference local peak data, and a third feature indicating the fracturing balance time consumption of the corresponding temperature difference local peak data, and the main fracture index is used to represent the probability of the corresponding temperature difference local peak data indicating the main fracture.

[0148] The main fracture identification module 204 is configured to identify a target sampling position indicating the main fracture from all sampling positions included in the target layer section based on the main fracture index of each temperature difference local peak data.

[0149] The operation result detection module 205 is configured to determine a target operation result according to the temperature changes of the plurality of target sampling positions in the target period and the number of the plurality of target sampling positions, wherein the target operation result is used to indicate whether the fracturing operation of the target layer section is stopped.

[0150] ​It should be noted that the device provided in the above embodiment is only used as an example for the division of the above function modules, and in actual application, the above functions can be completed by different function modules according to needs, that is, the internal structure of the computer device is divided into different function modules to complete all or part of the functions described above. In addition, the coiled tubing mechanical control type double-seal drag fracturing device and the coiled tubing mechanical control type double-seal drag fracturing method provided in the above embodiment belong to the same concept, and the specific implementation process is detailed in the method embodiment, which will not be repeated here.

[0151] The embodiment of the present application also provides an electronic device. Please refer to Figure 4 The electronic device can include a processor 301, a memory 302, and a program 3021 stored in the memory 302 and executable on the processor 301.

[0152] When the program 3021 is executed by the processor 301, the following functions can be implemented Figure 2 Any step in the corresponding method embodiment and the same beneficial effects can be achieved, which will not be repeated here.

[0153] Those skilled in the art can understand that all or part of the steps of the above-mentioned embodiment methods can be completed by program instructions related to hardware, and the program can be stored in a readable medium.

[0154] The embodiment of the present application also provides a readable storage medium, and the readable storage medium stores a computer program, and the computer program is executable by a processor to implement any step in the above-mentioned Figure 2 The corresponding method embodiment and the same technical effects can be achieved, and to avoid repetition, it will not be repeated here.

[0155] The computer readable storage medium of the embodiment of the present application can adopt any combination of one or more computer readable media. The computer readable medium can be a computer readable signal medium or a computer readable storage medium. The computer readable storage medium may, for example, be an electrical, magnetic, optical, electromagnetic, infrared, or semiconductor system, device or apparatus, or any combination of the above. More specific examples (non-exhaustive list) of the computer readable storage medium include an electrical connection having one or more wires, a portable computer diskette, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or flash memory), an optical fiber, a portable compact disk read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination of the above. In this document, the computer readable storage medium can be any tangible medium containing or storing a program that can be used by or in conjunction with an instruction execution system, device or apparatus.

[0156] Computer readable signal media can include a propagated data signal with computer readable program code embodied therein. For example, a propagated signal can be an electromagnetic signal, an optical signal, and / or any suitable combination thereof. Computer readable program code embodied on a computer readable medium can direct a computer to function in a particular manner, such as implementing an embodiment of the present application.

[0157] Program code embodied on a computer readable medium can be transmitted using any appropriate medium, including but not limited to wireless, wire line, optical fiber cable, RF, etc., or any suitable combination of the foregoing.

[0158] Computer program code for carrying out operations of the present application can be written in any combination of one or more programming languages, including an object oriented programming language such as Java, Smalltalk, C++ or the like and conventional procedural programming languages, such as the "C" programming language or similar programming languages. The program code can execute entirely on the user's computer, partly on the user's computer, as a stand-alone software package, partly on the user's computer and partly on a remote computer or entirely on the remote computer or server. In the latter scenario, the remote computer can be connected to the user's computer through any type of network, including a local area network (LAN) or a wide area network (WAN), or the connection can be made to an external computer (for example, through the Internet using an Internet Service Provider). These network connections are

[0159] The embodiment of the present application also provides a computer program product, which, when running on a computer, enables the computer to perform the above related steps, so as to realize the coiled tubing mechanical control type double-sealing drag fracturing method provided by the above embodiment.

[0160] It should be noted that the above-mentioned sequence of the embodiments of the present application is only for description, and does not represent the advantages and disadvantages of the embodiments. The processes depicted in the drawings do not necessarily require the specific order or continuous order shown to achieve the desired results. In some embodiments, multi-task processing and parallel processing are also possible or can be advantageous.

[0161] Each of the embodiments in the specification is described in a progressive manner, and the same and similar parts between the embodiments can be referred to each other. Each embodiment focuses on the difference from other embodiments.

Claims

1. A coiled tubing mechanically controlled dual packer bullheading fracturing method, characterized in that, The method comprises: With the reference interval as a reference, temperature changes of each sampling position in the target interval are analyzed to obtain a plurality of temperature difference data, wherein the reference interval is adjacent to the target interval and is in the same depth interval, and the plurality of temperature difference data correspond to a plurality of sampling positions in the target interval one by one; Local peak points of the plurality of temperature difference data are detected to determine a plurality of temperature difference local peak data; In the plurality of temperature difference local peak data, peak characteristic information of each temperature difference local peak data is analyzed to obtain a main fracture index of each temperature difference local peak data, wherein the peak characteristic information comprises a first characteristic indicating a peak height of the corresponding temperature difference local peak data, a second characteristic indicating a peak width of the corresponding temperature difference local peak data, and a third characteristic indicating a fracturing balance time consumption of the corresponding temperature difference local peak data, and the main fracture index is used to represent a probability that the corresponding temperature difference local peak data indicates a main fracture; Based on the main fracture index of each temperature difference local peak data, target sampling positions indicating main fractures are identified in all sampling positions included in the target interval; According to temperature changes of the plurality of target sampling positions in the target interval and a number of the plurality of target sampling positions, a target operation result is determined, wherein the target operation result is used to indicate whether fracturing operation of the target interval is stopped.

2. The coiled tubing mechanically controlled, dual packer, dart fracturing method of claim 1, wherein, The step of analyzing, with the reference interval as a reference, temperature changes of each sampling position in the target interval to obtain a plurality of temperature difference data comprises: At an end time of the target interval, an average value of temperature values of all sampling positions in the reference interval is calculated to obtain a reference temperature; In the target interval, differences between temperature average values of the plurality of sampling positions in the target interval and the reference temperature are analyzed to obtain a plurality of temperature difference data.

3. The coiled tubing mechanically controlled, dual packer, dart fracturing method of claim 2, wherein, The step of obtaining the third characteristic of each temperature difference local peak data in the plurality of temperature difference local peak data comprises: In the plurality of temperature difference local peak data, temperature changes of the sampling position indicated by each temperature difference local peak data after each temperature sampling time in the target interval are analyzed to determine a plurality of fracturing balance indexes associated with each temperature difference local peak data, wherein the plurality of fracturing balance indexes associated with each temperature difference local peak data correspond to the plurality of temperature sampling times in the target interval one by one; In the plurality of fracturing balance indexes associated with each temperature difference local peak data, a temperature sampling time corresponding to a maximum fracturing balance index is determined as a corresponding fracturing balance time to obtain a fracturing balance time corresponding to each temperature difference local peak data; According to a first time difference between the fracturing balance time corresponding to each temperature difference local peak data and a start time of the target interval, the third characteristic of each temperature difference local peak data is determined.

4. The coiled tubing mechanically controlled, dual packer, dart fracturing method of claim 3, wherein, The step of analyzing, in the plurality of temperature difference local peak data, temperature changes of the sampling position indicated by each temperature difference local peak data after each temperature sampling time in the target interval to determine a plurality of fracturing balance indexes associated with each temperature difference local peak data comprises: obtaining a plurality of backward temperature sequences associated with each of the temperature difference local peak data, wherein the plurality of backward temperature sequences correspond to a plurality of temperature sampling time points in the target period, and the backward temperature sequence comprises a plurality of temperature values collected from the corresponding temperature sampling time point to the end time point of the target period; analyzing the discrete degree of each backward temperature sequence associated with each of the temperature difference local peak data to obtain a plurality of temperature discrete coefficients associated with each of the temperature difference local peak data; analyzing a second time difference between each temperature sampling time point and the end time point of the target period to determine a time domain coefficient of each temperature sampling time point, wherein the time domain coefficient and the corresponding second time difference are in a negative correlation relationship; determining a fracturing balance index associated with each of the temperature difference local peak data according to each temperature discrete coefficient associated with each of the temperature difference local peak data and the corresponding time domain coefficient.

5. The coiled tubing mechanically controlled, dual packer, dart fracturing method of claim 1, wherein, The main fracture index is positively correlated with the first feature, the main fracture index is positively correlated with the second feature, and the main fracture index is positively correlated with the third feature.

6. The coiled tubing mechanically controlled, dual packer, dart fracturing method of claim 1, wherein, Based on the main fracture index of each temperature difference local peak data, the step of identifying a target sampling position indicating a main fracture from all sampling positions included in the target interval comprises: calculating the average value of the main fracture index of the plurality of temperature difference local peak data to obtain an index average value; in the plurality of temperature difference local peak data, determining the sampling position indicated by the temperature difference local peak data with the main fracture index greater than the index average value as the target sampling position.

7. The coiled tubing mechanically controlled, dual packer, dart fracturing method of claim 3, wherein, According to the temperature change of the plurality of target sampling positions in the target period and the number of the plurality of target sampling positions, the step of determining a target operation result comprises: analyzing the temperature rise degree of each target sampling position after the corresponding fracturing balance time to obtain a fracture saturation index of each target sampling position; determining a calculation weight of each target sampling position according to the fracturing balance index corresponding to each target sampling position; performing weighted calculation on the fracture saturation indices of the plurality of target sampling positions according to the calculation weights of the plurality of target sampling positions to obtain a pump saturation index; determining a target operation result according to the pump saturation index and the number of the plurality of target sampling positions.

8. The coiled tubing mechanically controlled, dual packer, dart fracturing method of claim 7, wherein, The step of determining a calculation weight of each target sampling position according to the fracturing balance index corresponding to each target sampling position comprises: calculating the sum value of the fracturing balance indices corresponding to the plurality of target sampling positions to obtain an index cumulative value; calculating the ratio of the fracturing balance index corresponding to each target sampling position to the index cumulative value to obtain the calculation weight of each target sampling position.

9. The coiled tubing mechanically controlled, dual packer, dart fracturing method of claim 7, wherein, The output probability of the target operation result indicating to stop the fracturing operation of the target interval is positively correlated with the number of the plurality of target sampling positions, and the output probability of the target operation result indicating to stop the fracturing operation of the target interval is positively correlated with the pump saturation index.

10. A coiled tubing mechanically controlled dual packer, slickline frac equipment, characterized in that, The device comprises: The data acquisition module is configured to analyze temperature changes of each sampling position in a target interval in a target period with reference to a reference interval, to obtain a plurality of temperature difference data, wherein the reference interval is adjacent to the target interval and is in the same depth interval, and the plurality of temperature difference data correspond to the plurality of sampling positions in the target interval one by one. The peak point detection module is configured to perform local peak point detection on the plurality of temperature difference data, to determine a plurality of temperature difference local peak data. The feature analysis module is configured to analyze peak feature information of each temperature difference local peak data from the plurality of temperature difference local peak data, to obtain a main fracture index of each temperature difference local peak data, wherein the peak feature information includes a first feature indicating a peak height of the corresponding temperature difference local peak data, a second feature indicating a peak width of the corresponding temperature difference local peak data, and a third feature indicating a fracturing balance time consumption of the corresponding temperature difference local peak data, and the main fracture index is used to represent a probability that the corresponding temperature difference local peak data indicates a main fracture. The main fracture identification module is configured to identify target sampling positions indicating a main fracture from all sampling positions included in the target interval based on the main fracture index of each temperature difference local peak data. The operation result detection module is configured to determine a target operation result according to temperature changes of the plurality of target sampling positions in the target period and a number of the plurality of target sampling positions, wherein the target operation result is used to indicate whether fracturing operation of the target interval is stopped.

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