A detection and acquisition device and detection method for the distribution of fracturing fluid in shale fractures

Abstract

The present invention relates to the technical field of shale gas extraction, and provides a detection and acquisition device and a detection method for the distribution of fracturing fluid in shale fractures, including a main body mechanism, an acquisition mechanism, a support mechanism, a detection mechanism and a driving mechanism. It can perform periodic segmented detection and acquisition. Through the controllable addition of a color reagent and the cooperation of a spectrophotometer detection module, specific concentration detection of a tracer is carried out. Through the setting of a computer and a controller, an automated control detection and acquisition are formed, and sample detection and acquisition and real-time transmission can be completed without manual attendance and operation, providing subsequent detection convenience and accuracy for the distribution and retention of fracturing fluid in shale fractures.

Description

Technical Field

[0001] The present invention relates to the technical field of shale gas extraction, and in particular, to a device and method for detecting and collecting the distribution of fracturing fluid in shale fractures. Background Art

[0002] In the process of shale gas extraction, injecting fracturing fluid into shale fractures is a key technical link. After the fracturing fluid is injected into the formation by a high-pressure pump, the pressure exerted on the rock exceeds its fracture strength, causing initial fractures to form inside the shale. With continuous injection, the liquid pressure promotes the expansion of the original fractures and interconnects with other natural or artificial fractures, ultimately forming a complex network fracture system, significantly enhancing the permeability of the reservoir. After injecting the fracturing fluid into the casing through the fracturing fluid technology, in order to maintain quantitative analysis of the fracture opening degree and fluid distribution range of each fracturing interval during the extraction process, and to judge the effective transformation area of the reservoir and the contribution rate of the main production layer, it is necessary to monitor the distribution of fracturing fluid in shale fractures to make a determination. In the prior art for monitoring the distribution of fracturing fluid, it is mainly completed through fiber optic sensing, microseismic monitoring technology, and tracer technology. Among them, tracer technology mainly includes radioactive tracer testing and chemical tracer monitoring. Since radioactive tracers contain radioactive substances and have a strong environmental pollution, most still use chemical tracer monitoring methods for monitoring and treatment. By combining the staged release method with the dynamic curve of the backflow fluid concentration, the distribution differences of fracturing fluid between main fractures and secondary fractures can be quickly identified to guide the optimization of fracturing intervals;

[0003] In the monitoring method of chemical tracers, mainly during the fracturing construction process, the tracer is mixed into the fracturing fluid in a certain proportion and injected into the casing together with the fracturing fluid. During the backflow stage after fracturing, backflow fluid samples are collected at regular intervals. By combining the composition of the backflow fluid and the characteristics of the backflow curve, and cross-verifying with the fracture geometry data of the fracture inclinometer, the retention ratio of fracturing fluid in distal fractures or near-well zones can be determined.

[0004] Currently, during the initial rapid backflow stage of the backflow fluid, it is necessary to collect and then detect. During collection, it is necessary to collect once every thirty minutes at the collection point. During the later steady-state backflow stage, it is necessary to collect once every two hours. In this process, the collection process is completely handled manually and requires periodic quantitative collection according to time, and then cooperate with the detection instrument for detection operations. The collection volume and process are both manually operated, with uncertainties, and it is necessary to stay near the collection point for a long time. Within a thirty-minute interval, the collected samples need to be frequently transferred and combined with the instrument for monitoring the concentration of suspended solids and proppants, consuming energy and time, affecting the stability of long-term staged collection and subsequent detection and use, and having certain drawbacks. Summary of the Invention

[0005] The first purpose of the present invention is to provide a fracturing fluid distribution detection and collection device in shale fractures, which can perform periodic segmented collection and detection, detect specific concentrations of tracers through controllable addition of color developers in conjunction with spectrophotometer detection modules, and form automated control collection and detection through computer and controller settings. Sample collection and detection and real-time transmission can be completed without manual supervision and operation, providing convenience and accuracy for subsequent detection of the distribution and retention of fracturing fluid in shale fractures.

[0006] Another object of the present invention is to provide a method for detecting the distribution points of fracturing fluid in shale fractures, which optimizes the fracturing design by processing the data obtained by the collection and detection device, combining the tracer return curve, fracture conductivity and other parameters through algorithm modeling.

[0007] In order to solve the above technical problems, the technical solution adopted in this application is:

[0008] In a first aspect, an embodiment of the present application provides a fracturing fluid distribution detection and collection device in a shale fracture, which includes a main body mechanism, an outer side wall of the main body mechanism is connected to a valve pipe rack and a reagent valve pipe, the valve pipe rack is used to transport a backflow liquid sample, the reagent valve pipe is used to inject a color developer into the backflow liquid sample, a collection mechanism, the collection mechanism is sleeved on a supporting mechanism, and the collection mechanism is abutted against and connected to the valve pipe rack, a supporting mechanism, the supporting mechanism is sleeved on the main body mechanism, and the supporting mechanism is rotatably connected to the main body mechanism, the supporting mechanism is fixedly connected to the collection mechanism so that the collection mechanism is rotationally matched with the main body mechanism through the supporting mechanism, a detection mechanism, the detection mechanism is fixedly connected to the main body mechanism through a support arm, a spectrophotometer detection module is provided on the detection mechanism, which is used to cooperate with the collection mechanism and detect the absorbance of the backflow liquid sample to wavelength light, and a driving mechanism, the driving mechanism is provided on the support arm, and the driving mechanism is abutted against the collection mechanism, and is used to control the rotation of the collection mechanism.

[0009] The main body is installed in the backflow pipeline, and the backflow sample with the tracer is collected through the valve tube rack and transported to the collection mechanism. In order to detect the concentration of the tracer later, a reagent valve tube is provided. The reagent valve tube is used to inject the thiocyanate color developer into the sample to make the tracer develop color. This structure is a targeted design for tracer detection. The sample after color development is rotated to the detection mechanism, and the sample's absorbance of light of a specific wavelength is determined by the spectrophotometer detection module to obtain the tracer concentration. The detection module transmits the data to the laboratory in real time for subsequent processing. The set driving mechanism provides power support for automatic sampling and detection, so that the device of the present application can be completely free from manual control. After setting the collection target, fully automatic collection and detection can be achieved without manual sampling and manual detection of tracer concentration, which significantly reduces labor costs and time costs and provides accurate detection data.

[0010] Further, the above-mentioned main body mechanism includes a main rod frame. A discharge pipe is connected to the top end of the main rod frame, and a base plate is connected to the lower end of the main rod frame. A discharge pipe is also communicated with the bottom side wall of the main rod frame. Flanges are connected to one ends of the discharge pipe and the discharge pipe away from the main rod frame, and the discharge pipe and the discharge pipe are communicated with each other. A filter cylinder is detachably arranged in the discharge pipe. A grid filter layer is connected to the inner wall of the filter cylinder. The valve pipe frame is communicated with the discharge pipe. The main rod frame is communicated with the external pipeline through the discharge pipe and the discharge pipe to form a reverse drainage flow channel. The filter cylinder and the grid filter layer in the discharge pipe preliminarily filter the reverse drainage liquid to remove suspended matters and large particle impurities, so that the sample reaches the linear range of the spectrophotometer detection, avoiding the absorbance exceeding the detection upper limit. The valve pipe frame is communicated with the discharge pipe to transport the reverse drainage liquid sample. The detachable filter cylinder is convenient for cleaning and maintenance.

[0011] Further, the above-mentioned support mechanism includes a bearing frame and a connecting frame. The bearing frame is sleeved and fixed on the main rod frame, and the connecting frame is fixedly connected to the bearing frame, so that the connecting frame is rotationally matched with the main rod frame. The collection mechanism is sleeved on the main rod frame, and the collection mechanism is fixedly connected to the connecting frame. The bearing frame is sleeved and fixed on the main rod frame, and the connecting frame is connected to the bearing frame, so that the connecting frame can rotate around the main rod frame. The collection mechanism is fixedly connected to the connecting frame. Thus, the rotation of the support mechanism drives the collection mechanism to rotate relative to the main body mechanism, realizing long-term interval collection.

[0012] Further, the above-mentioned collection mechanism includes a collection ring. A rack is circumferentially arranged on the inner wall of the collection ring, and a plurality of insertion holes are also circumferentially spaced on the inner wall of the collection ring. A plurality of sample accommodation components are circumferentially spaced on the outer side wall of the collection ring. The plurality of insertion holes correspond to and communicate with the plurality of sample accommodation components one by one. The insertion holes on the collection ring communicate with the sample accommodation components. The reverse drainage liquid sample enters the sample accommodation components through the insertion holes, realizing fixed-point collection of the sample. The rotation angle of the collection ring is precisely controlled by rack transmission, so that the sample accommodation components are sequentially aligned with the valve pipe frame, realizing automatic switching collection of multiple samples, capable of supporting batch collection of reverse drainage liquid samples at different time periods, improving the collection efficiency, and providing conditions for subsequent time-segment analysis.

[0013] Further, the above-mentioned sample accommodation component includes a collection needle, a docking pipe and a sample tube. The collection needle is connected to the outer side wall of the collection ring and is communicated with the insertion hole. One end of the collection needle away from the main rod frame is communicated with the docking pipe, and one end of the docking pipe away from the collection needle is communicated with the sample tube. An outer rubber plug is also arranged between the docking pipe and the collection needle. A plurality of inner rubber plugs are circumferentially distributed on the inner wall of the docking pipe. The reverse drainage liquid sample enters the docking pipe through the collection needle. The inner rubber plugs on the inner wall of the docking pipe and the outer rubber plug on the outside form a double seal. The inner rubber plugs make the sample tube tightly inserted into the collection needle, preventing sample leakage or external contamination. Finally, the sample flows into the sample tube for storage, ensuring the integrity and purity of the sample, avoiding detection errors caused by contamination, and improving the accuracy of the detection result.

[0014] Further, the above sample tube is made of a transparent material so that the sample tube meets the detection requirements under the spectrophotometer detection module.

[0015] Further, the above detection mechanism includes a housing, a computer module, and a spectrophotometer detection module. The housing is located at the top of the support arm, the computer module is located inside the housing, the spectrophotometer detection module is located at the bottom of the support arm, and the spectrophotometer detection module is electrically connected to the computer module. The spectrophotometer detection module is provided with a detection chamber for accommodating the sample tube. The spectrophotometer detection module accommodates the sample tube through the detection chamber, measures the absorbance of the sample to light of a specific wavelength using spectrophotometry, and the computer module processes and analyzes the detection data in real time, establishes the corresponding relationship between the absorbance and the concentration of the sample components, realizes the quantitative detection of the sample components, quickly obtains the concentration data, improves the automation degree and accuracy of the detection, and provides efficient data processing capabilities for real-time monitoring of the fracturing fluid distribution.

[0016] Further, the above driving mechanism includes a servo motor, a gear, a controller, a power supply, and a communication module. The servo motor is embedded at the bottom of the support arm, the bottom end of the servo motor is electrically connected to a gear, the gear meshes with a rack, one side of the servo motor is also electrically connected to the controller, the power supply is located inside the housing, the communication module is located on one side of the power supply, and the communication module is electrically connected to the power supply. Both the controller and the computer module are electrically connected to the power supply. The servo motor meshes with the rack of the collection ring through the gear. The controller sends a signal to control the rotation of the servo motor, drives the collection ring to accurately rotate to the specified position. The power supply supplies power to each electronic component, and the communication module realizes the data transmission between the device and the external system, accurately controls the rotation angle and speed of the collection mechanism, realizes the automatic positioning and collection actions, reduces the manual operation error, improves the stability and reliability of the device operation, and supports remote control and real-time data transmission.

[0017] Further, the above valve pipe rack includes a solenoid valve pipe. One end of the solenoid valve pipe close to the main rod rack is communicated with an inner pipe, the inner pipe is communicated with a discharge pipe, the end of the solenoid valve pipe far from the inner pipe is communicated with a telescopic pipe, the end of the telescopic pipe far from the solenoid valve pipe is connected to a structural plate, an electric telescopic rod is connected to the inner wall of the structural plate, the electric telescopic rod is also connected to the solenoid valve pipe, a soft rubber pad is connected to the outer wall of the structural plate, a plugging cone head is connected to the middle of the soft rubber pad, the plugging cone head is communicated with the inner pipe through the telescopic pipe, the solenoid valve pipe is communicated with the discharge pipe through the inner pipe. The electric telescopic rod adjusts the length of the telescopic pipe, so that the plugging cone head can be inserted into the plugging hole to realize the accurate injection of the sample. The soft rubber pad and the plugging cone head ensure the connection sealing performance, and realize the automatic sampling and transportation of the sample.

[0018] Furthermore, a reagent chamber for accommodating a chromogenic agent is provided inside the main rod frame. The reagent valve tube is communicated with the accommodating chamber and the reagent chamber, and the chromogenic agent is transported to the sample to undergo a chromogenic reaction with the tracer, facilitating subsequent spectral detection. It integrates the function of storing the chromogenic agent, simplifies the pipeline connection, ensures the supply of the chromogenic agent as needed, reduces the dependence on external reagent tanks, saves equipment space, improves the operation convenience and system integration. The reagent valve tube has the same structure as the valve tube frame. After the valve tube frame injects the sample into the sample tube, the rotating collection ring is docked with the reagent valve tube, and the chromogenic agent is injected into the sample by the reagent valve tube to complete the chromogenic operation. The injection amount of the chromogenic agent is automatically controlled according to the detection requirements to ensure the accuracy of the chromogenic reaction, realize the automatic addition of the chromogenic agent, avoid the cumbersome manual operation and errors, and improve the standardization degree of the detection process.

[0019] Second aspect, an embodiment of the present application provides a method for detecting the distribution points of fracturing fluid in shale fractures, including the following steps: S1. Fracturing fluid injection: According to the multi-stage fracturing division of the on-site environment, tracers with different concentrations are selected, and tracers with different identifications are added to different fracturing sections of the fracturing fluid. S2. Backflow fluid collection: The detection and sampling device is installed at the required sampling position, the discharge pipe is connected to the backflow pump pipeline, and the backflow fluid sample is collected regularly through the detection and sampling device, and the backflow volume at the collection time is recorded. S3. Collection in time periods: By setting the initial time for the controller, collection is carried out once every thirty minutes during the initial rapid backflow stage to monitor the changes in the concentration of suspended solids and proppants in the backflow fluid. After the backflow reaches a steady state, collection is carried out once every two hours to analyze the content of soluble salts and oils. S4. Data analysis and transmission: The concentration information detected by the collection device is transmitted to the laboratory in real time through the communication module. The concentration values at each time point are sorted according to the sampling time based on the concentration detection results transmitted by the collection device to generate an original concentration scatter plot. The moving average method or polynomial fitting is used to eliminate random noise to obtain a continuous concentration change curve. S5. Dynamic data analysis: After the communication module transmits the concentration and collection volume information, the water production rate and recovery rate are calculated by combining the concentration and the total amount of backflow fluid. The adsorption rate of oil sand and crude oil to the chemical tracer used in this time is obtained through laboratory adsorption tests. The actual concentration monitoring data is tested and corrected, and the appearance order, concentration peak value and attenuation law of the tracers in each section are monitored during the backflow stage, so as to quantitatively characterize the dynamic sequence of the fluid contribution of each layer section and obtain the tracer backflow sequence. S6. Monitoring result processing: Combining the characteristics of the concentration change curve to infer the fracture length and conductivity, optimize the subsequent fracturing design. Through the tracer collection device to monitor and identify the backflow fracturing fluid and the recovery rate provided by the laboratory, estimate the distribution of the unreturned fluid retained in the formation. S7. Data interpretation and modeling: Estimate the effective fracture volume through the total amount of tracer backflow in the backflow fluid obtained from this experiment. Combining the tracer backflow sequence, distinguish the main fracture, secondary fracture and natural fracture. According to the tracer backflow rate and the effective fracture volume estimated by the total amount of tracer backflow, analyze the change of fracture conductivity. Combining microseismic detection and distributed optical fiber temperature measurement data, verify the tracer detection results.

[0020] Further, in step S1, non-radioactive chemical tracers are selected, such as SCN or boron, etc., which need to have low adsorption, high stability and easy detectability, avoid adsorption interference with formation substances, and add tracers with different identifications at different stages of the fracturing fluid to ensure that each section of the fracturing fluid corresponds to a specific tracer, which is convenient for subsequent distinction of the backflow source.

[0021] Further, in step S3, it is necessary to use the color reaction method to react the specific reagent thiocyanate color reagent with the tracer to generate a colored substance. Through the reagent valve tube connected to the reagent chamber part, it is inserted and communicated with the sampled sample tube after collection, so that the thiocyanate color reagent reacts with the tracer in the sample tube to generate a colored substance. The sample tube is aligned with the upper and lower spectrophotometer detection module parts through a transparent material, and the concentration is calculated by matching the absorbance with the standard curve.

[0022] Further, in step S7, it is necessary to use special software or algorithms for auxiliary simulation. The software can use the FracPredictor integrated geotechnical software, apply artificial intelligence non-linear neural network technology to perform intelligent analysis on natural fracture modeling and fracturing simulation data, use the MPM algorithm to simulate the artificial fracturing effect, support the dynamic inversion of the fracturing fluid flowback rate and fracture parameters. The algorithm realizes data visualization and multi-parameter comprehensive comparison through grey relational analysis, improving the analysis efficiency. The grey relational analysis algorithm is used for multi-parameters, including the correlation analysis between tracer concentration, flowback fluid volume, and fracture conductivity, to identify the key factors affecting the flowback dynamics. The real-time collection and dynamic analysis of fracturing fluid flowback data are realized through special software, improving the operation efficiency. The system based on Qt supports cross-platform integration of tracer data with geological and engineering parameters, reducing the error of manual intervention. The fracture propagation path and the risk of fracturing fluid retention can be simulated through the MPM algorithm and artificial intelligence technology, providing a basis for environmental assessment.

[0023] Compared with the prior art, the embodiments of the present invention have at least the following advantages or beneficial effects:

[0024] 1. The collection ring with a rotating structure is connected to the flowback liquid pipeline for periodic segmented collection and monitoring. With the controllable addition of the color reagent in the reagent chamber, the sample can be detected for concentration through the spectrophotometer detection module, and a periodic collection and detection process is carried out. The overall collection and detection module is formed by the automatic control of each component by the computer-set time and the controller, so as to achieve the purpose of automatic segmented collection and detection. Without manual attendance and operation, the sample collection, detection, and real-time transmission can be completed, providing convenience and accuracy for subsequent detection of the distribution and retention of fracturing fluid in shale fractures.

[0025] 2. During the discharge process of the flowback liquid, the large-particle impurities in the flowback liquid can be pre-treated and filtered through the connected filter cartridge part in cooperation with the internal grid filter layer, thus providing convenience for the subsequent sampling and detection process. At the same time, a reagent chamber is provided on one side of the inner wall of the main rod frame. Through the reagent valve tube connected to the reagent chamber part, it is inserted and communicated with the sampled sample tube after collection, so that the thiocyanate color reagent reacts with the tracer in the sample tube to generate a colored substance, which is convenient for subsequent concentration detection.

[0026] 3. It can be successively docked with the valve pipe rack or the reagent valve pipe through the socket holes distributed on the inner wall of the collection ring. The valve pipe rack injects the reverse drainage liquid carrying the tracer, which is collected in the connected sample tube. The reagent valve pipe can rotate with the collection ring and be inserted into the sample tube to inject the thiocyanate color reagent, causing it to react with the tracer in the tube to generate a colored substance. At the same time, the sample tube is aligned with the spectrophotometer detection module for detection, saving subsequent laboratory steps and calculating the concentration in conjunction with the standard curve, further improving the detection efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] To more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for the embodiments. It should be understood that the following drawings only show some embodiments of the present invention and should not be regarded as limiting the scope. For those of ordinary skill in the art, other related drawings can be obtained based on these drawings without creative efforts.

[0028] Figure 1 FIG. is a schematic diagram of the overall structure of a detection and collection device for the distribution of fracturing fluid in shale fractures provided by the present invention;

[0029] Figure 2 FIG. is a schematic diagram of the internal structure of a detection and collection device for the distribution of fracturing fluid in shale fractures provided by the present invention Figure 1 ;

[0030] Figure 3 FIG. is a schematic diagram of the internal structure of a detection and collection device for the distribution of fracturing fluid in shale fractures provided by the present invention Figure 2 ;

[0031] Figure 4 FIG. is a schematic diagram of the valve pipe rack structure of a detection and collection device for the distribution of fracturing fluid in shale fractures provided by the present invention;

[0032] Figure 5 FIG. is a schematic diagram of the collection ring structure of a detection and collection device for the distribution of fracturing fluid in shale fractures provided by the present invention Figure 1 ;

[0033] Figure 6 FIG. is a schematic diagram of the collection ring structure of a detection and collection device for the distribution of fracturing fluid in shale fractures provided by the present invention Figure 2 ;

[0034] Figure 7 FIG. is a schematic diagram of the sample tube structure of a detection and collection device for the distribution of fracturing fluid in shale fractures provided by the present invention;

[0035] Figure 8 FIG. is a schematic diagram of the detection mechanism and the driving mechanism structure of a detection and collection device for the distribution of fracturing fluid in shale fractures provided by the present invention;

[0036] Figure 9 Schematic flow chart of a method for detecting the distribution points of fracturing fluid in shale fractures provided by the present invention.

[0037] Icon: 1 - Main body mechanism; 101 - Main rod frame; 102 - Base plate; 103 - Drain pipe; 104 - Discharge pipe; 105 - Flange; 106 - Reagent valve pipe; 107 - Reagent chamber; 108 - Filter cartridge; 109 - Mesh filter layer; 2 - Valve pipe frame; 201 - Solenoid valve pipe; 202 - Inner pipe; 203 - Telescopic pipe; 204 - Structural plate; 205 - Electric telescopic rod; 206 - Soft rubber pad; 207 - Plugging cone head; 3 - Collection mechanism; 301 - Collection ring; 302 - Connecting frame; 303 - Bearing frame; 304 - Rack; 305 - Plugging hole; 306 - Collection needle; 307 - Sample tube; 308 - Docking pipe; 309 - Outer rubber plug; 310 - Inner rubber plug; 311 - Spectrophotometer detection module; 312 - Support arm; 313 - Servo motor; 314 - Gear; 315 - Controller; 316 - Power supply; 317 - Communication module; 318 - Computer module. Detailed implementation manners

[0038] To make the objectives, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Apparently, the described embodiments are some but not all of the embodiments of the present invention. The components of the embodiments of the present invention described and illustrated herein usually can be arranged and designed in various different configurations.

[0039] Therefore, the following detailed description of the embodiments of the present invention provided in the drawings is not intended to limit the scope of the claimed present invention, but merely represents selected embodiments of the present invention. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts fall within the scope of protection of the present invention.

[0040] The features and performance of the present invention will be further described in detail below in combination with the embodiments.

[0041] Embodiment 1:

[0042] Please refer to Figures 1-8 , Figure 1 which shows the overall structure schematic diagram of the present invention; Figure 2 which shows the internal structure schematic Figure 1 ; Figure 3 which shows the internal structure schematic Figure 2 ; Figure 4 which shows the valve pipe frame structure schematic diagram of the present invention; Figure 5 which shows the collection ring structure schematicFigure 1 ; Figure 6 The structural schematic diagram of the collection ring of the present invention is shown; Figure 2 ; Figure 7 The structural schematic diagram of the sample tube of the present invention is shown; Figure 8 The structural schematic diagram of the detection mechanism and the driving mechanism of the present invention is shown.

[0043] As Figures 1-3 shown, this embodiment provides a detection and collection device for the distribution of fracturing fluid in shale fractures, including a main body mechanism. A valve pipe rack and a reagent valve pipe are connected to the outer side wall of the main body mechanism. The valve pipe rack is used to transport the backflow liquid sample, and the reagent valve pipe is used to inject a color developing agent into the backflow liquid sample; a collection mechanism, the collection mechanism is sleeved on the support mechanism, and the collection mechanism is in contact with and communicated with the valve pipe rack; a support mechanism, the support mechanism is sleeved on the main body mechanism, and the support mechanism is rotatably connected to the main body mechanism, and the support mechanism is fixedly connected to the collection mechanism, so that the collection mechanism is rotationally matched with the main body mechanism through the support mechanism; a detection mechanism, the detection mechanism is fixedly connected to the main body mechanism through a support arm, and a spectrophotometer detection module is arranged on the detection mechanism, which is used to cooperate with the collection mechanism and detect the absorbance of the backflow liquid sample to the wavelength light; a driving mechanism, the driving mechanism is arranged on the support arm, and the driving mechanism is in contact with the collection mechanism, which is used to control the rotation of the collection mechanism.

[0044] As Figures 1-3 shown, in this embodiment, the above-mentioned main body mechanism includes a main rod frame. A discharge pipe is connected to the top end of the main rod frame, a base plate is connected to the low end of the main rod frame, a discharge pipe is also communicated with the bottom side wall of the main rod frame. Flanges are connected to the ends of the discharge pipe and the discharge pipe far from the main rod frame, and the discharge pipe and the discharge pipe are communicated with each other. A filter cylinder is detachably arranged in the discharge pipe, a grid filter layer is connected to the inner wall of the filter cylinder, and the valve pipe rack is communicated with the discharge pipe.

[0045] As Figures 1-3 shown, in this embodiment, the above-mentioned support mechanism includes a bearing frame and a connection frame. The bearing frame is sleeved and fixed on the main rod frame, and the connection frame is fixedly connected to the bearing frame, so that the connection frame is rotationally matched with the main rod frame. The collection mechanism is sleeved on the main rod frame, and the collection mechanism is fixedly connected to the connection frame.

[0046] As Figures 5-6 shown, in this embodiment, the above-mentioned collection mechanism includes a collection ring. A rack is circumferentially arranged on the inner wall of the collection ring, and a plurality of insertion holes are circumferentially and spaced apart on the inner wall of the collection ring. A plurality of sample accommodation components are circumferentially spaced on the outer side wall of the collection ring. The plurality of insertion holes correspond to and communicate with the plurality of sample accommodation components one by one.

[0047] As Figures 5-7As shown, in this embodiment, the above-mentioned sample accommodation component includes a collection needle, a docking tube, and a sample tube. The collection needle is connected to the outer wall of the collection ring and is in communication with the insertion hole. The end of the collection needle away from the main rod frame is in communication with the docking tube, and the end of the docking tube away from the collection needle is in communication with the sample tube. An outer rubber stopper is also provided between the docking tube and the collection needle, and a number of inner rubber stoppers are annularly arranged on the inner wall of the docking tube.

[0048] As Figures 7-8 shown, in this embodiment, the above-mentioned sample tube is made of a transparent material so that the sample tube meets the detection requirements under the spectrophotometer detection module.

[0049] As Figure 8 shown, in this embodiment, the above-mentioned detection mechanism includes a housing, a computer module, and a spectrophotometer detection module. The housing is located at the top of the support arm, the computer module is located inside the housing, the spectrophotometer detection module is located at the bottom of the support arm, and the spectrophotometer detection module is electrically connected to the computer module. The spectrophotometer detection module is provided with a detection chamber for accommodating the sample tube.

[0050] As Figure 8 shown, in this embodiment, the above-mentioned driving mechanism includes a servo motor, a gear, a controller, a power supply, and a communication module. The servo motor is embedded at the bottom of the support arm, the bottom end of the servo motor is electrically connected to the gear, the gear meshes with the rack, one side of the servo motor is also electrically connected to the controller, the power supply is located inside the housing, the communication module is located on one side of the power supply, and the communication module is electrically connected to the power supply. Both the controller and the computer module are electrically connected to the power supply.

[0051] As Figure 4 shown, in this embodiment, the above-mentioned valve tube holder includes a solenoid valve tube. One end of the solenoid valve tube close to the main rod frame is in communication with an inner tube, the inner tube is in communication with the discharge tube, the end of the solenoid valve tube away from the inner tube is in communication with a telescopic tube, the end of the telescopic tube away from the solenoid valve tube is connected to a structural plate, an electric telescopic rod is connected to the inner wall of the structural plate, the electric telescopic rod is also connected to the solenoid valve tube, a soft rubber pad is connected to the outer wall of the structural plate, a plugging cone head is connected to the middle of the soft rubber pad, and the plugging cone head is in communication with the inner tube through the telescopic tube.

[0052] As Figure 3 shown, in this embodiment, a reagent chamber for accommodating the developer is provided inside the main rod frame, and the reagent valve tube is in communication with the accommodation chamber.

[0053] When in use, the above-mentioned collection device for detection can be stably placed near the collection point through the base plate at the bottom of the main rod frame. Flanges are connected to both the drain pipe and the discharge pipe connected to the main rod frame. The drain pipe can be connected to the discharge pump to conduct connected discharge during the reverse liquid discharge process, and cooperate with the discharge pipe to discharge the reverse liquid to the treatment point without affecting the normal reverse discharge of the fracturing fluid. During the reverse liquid discharge process, through the connected filter cartridge part, the large-particle impurities in the reverse liquid can be pre-treated and filtered with the internal grid filter layer, thus facilitating the subsequent sampling and detection process. At the same time, a reagent chamber is provided on one side of the inner wall of the main rod frame. The reagent valve pipe connected to the reagent chamber part can be inserted and connected to the sample tube after collection, so that the thiocyanate color-developing agent reacts with the tracer in the sample tube to generate a colored substance, which is convenient for subsequent concentration detection.

[0054] When in use, the solenoid valve pipe part in the above is electrically connected to the controller to maintain controllability. It can be opened and closed once every thirty minutes, so that the connected inner pipe collects the reverse liquid discharged into the main body mechanism. Its electric telescopic rod can push the structural plate and the telescopic pipe to extend, so as to cooperate with the insertion cone at the end of the telescopic pipe to be inserted and connected to the insertion hole on the inner wall of the collection ring, maintaining a stable and controllable collection process.

[0055] When in use, the above-mentioned device can be fixedly connected to the outer wall of the bottom bearing frame through the connecting brackets connected to the four weeks at the bottom of the collection ring to form an integral body, and the bearing frame is fixed to the outer wall of the main rod frame. Thus, the collection ring can rotate with the main rod frame as the axis. The rotation process of the collection ring is completely controlled by the servo motor. The controller can perform periodic servo motor control according to the set time, making the gear connected to the bottom of the servo motor rotate, and then cooperating with the meshing rack to form friction, so that the collection ring connected to the rack rotates along the axis of the main rod frame. The reverse liquid collection process can be carried out once every thirty minutes according to the set time, so that automatic collection can be realized without the need for personnel to watch.

[0056] During the above collection process, the plugging holes distributed on the inner wall of the collection ring can be successively docked with the valve pipe rack or the reagent valve pipe. The valve pipe rack injects the backflow liquid carrying the tracer, which is collected in the connected sample tube. In the docking pipe part, the inner rubber plug arranged on the inner wall and the outer rubber plug at the docking place are combined to form a connected state, maintaining the sealing and stability during the collection process. The reagent valve pipe can rotate with the collection ring and be inserted into the sample tube to inject the thiocyanate color reagent, causing it to react with the tracer in the tube to generate a colored substance. At the same time, the sample tube is aligned with the spectrophotometer detection module. According to the preset injection volume, the reagent in the reagent chamber is quantitatively injected into the sample tube. The principle of using the thiocyanate color reagent in the reagent chamber is that nitrate ions react with a specific color reagent to generate a colored substance. The absorbance is measured using a spectrophotometer, and the concentration value is calculated according to the standard curve. Thus, by using a continuous spectrum light source, such as a tungsten lamp or a tungsten halogen lamp for the visible light region, and a hydrogen lamp or a deuterium lamp for the ultraviolet light region, by measuring the absorption intensity or absorbance of the backflow liquid sample for light of a specific wavelength, and combining with Lambert-Beer's law to calculate the concentration or composition, and then detecting the aligned sample tube to obtain the concentration data.

[0057] During the detection process, the concentration measurement data can be processed by a computer module connected to the spectrophotometer detection module, and the concentration data can be transmitted to the laboratory in real time through the communication module. Thus, the sample information for this period can be provided in the first time. By connecting the computer-set time to the controller, an automated control process for each group of components is formed, achieving the purpose of segmented collection and detection. Without manual attendance and operation, the sample collection can be completed, providing convenience and accuracy for subsequent detection of the distribution and retention of fracturing fluid in shale fractures.

[0058] Embodiment 2:

[0059] Please refer to Figure 9 , Figure 9 The following shows the method flow schematic diagram of a method for detecting the distribution points of fracturing fluid in shale fractures according to the present invention.

[0060] As Figure 9 shown, this embodiment provides a method for detecting the distribution points of fracturing fluid in shale fractures, including the following steps:

[0061] S1. Fracturing fluid injection: According to the multi-stage fracturing division of the on-site environment, if it is multi-stage fracturing in a horizontal well, different concentrations of tracers are used for each stage. After determining the chemical tracer to be used, tracers with different identifications are added to different fracturing stages of the fracturing fluid.

[0062] S2. Backflow liquid collection: Place the detection and sampling device at the required sampling point, connect the discharge pipe to the pump pipe of the backflow, and regularly collect the backflow liquid sample through the detection and sampling device, and record the backflow volume at the time of collection.

[0063] S3. Collection by time period: By setting the initial time for the controller, collection is carried out once every thirty minutes during the initial rapid backflow stage to monitor the changes in the concentration of suspended solids and proppant in the backflow fluid. After the backflow reaches a steady state, collection is carried out once every two hours to analyze the content of dissolved salts and oils.

[0064] S4. Data analysis and transmission: The concentration information detected by this collection device is transmitted to the laboratory in real time through the communication module. According to the concentration detection results in the collection device, the concentration values at each time point are sorted according to the sampling time to generate an original concentration scatter plot. The moving average method or polynomial fitting is used to eliminate random noise and obtain a continuous concentration change curve.

[0065] S5. Dynamic data analysis: After the communication module transmits the concentration and collection volume information, the water production rate and recovery rate are calculated by combining the transmitted concentration data and the total backflow fluid volume data. Subsequently, the adsorption rate of the tracer by oil sand and crude oil is obtained through laboratory adsorption tests to test and correct the actual monitoring data. The water production rate and recovery rate data are obtained by monitoring the volume of the backflow fluid at different stages, such as the fracturing backflow fluid stage and the produced water stage, and the index concentrations in the collected test tubes, such as Cl⁻, TDS, suspended solids, etc. The critical point between the fracturing backflow fluid and the produced water is divided according to the concentration change. The volume of the fracturing backflow fluid and the volume of the produced water are respectively counted to obtain the water production rate. Subsequently, according to the total amount of fracturing fluid injected in this experiment, and then comparing with the total amount of backflow fluid after complete collection, the recovery rate can be obtained. At the same time, during the backflow stage, the appearance sequence, concentration peak value and attenuation law of each section of the tracer are monitored, so as to quantitatively characterize the dynamic sequence of the fluid contribution of each layer section and obtain the tracer backflow sequence.

[0066] S6. Monitoring result processing: Based on the characteristics of the concentration change curve, the fracture length and conductivity are inferred to optimize the subsequent fracturing design. Through the monitoring and identification of the backflow fracturing fluid by this tracer collection device and the recovery rate provided by the laboratory, the distribution of the unbackflow fluid retained in the formation is calculated.

[0067] S7. Data interpretation and modeling: The effective fracture volume is estimated by the total amount of tracer backflow in the backflow fluid obtained from this experiment. Combining the above tracer backflow sequence, the main fractures, secondary fractures and natural fractures are distinguished. According to the tracer backflow rate and the effective fracture volume estimated by the total amount of tracer backflow, the change in fracture conductivity is analyzed. Combining microseismic detection and distributed optical fiber temperature measurement data, the tracer detection results are verified.

[0068] In summary, the present invention provides a device and method for detecting and collecting the distribution of fracturing fluid in shale fractures. When injecting fracturing fluid, according to the multi-stage fracturing division of the on-site environment, if it is multi-stage fracturing in a horizontal well, tracers with different concentrations are used for each stage. After determining the chemical tracer to be used, tracer drainage fluids with different identifiers are added to different fracturing stages of the fracturing fluid for collection. When installing this detection and collection device, first connect the drainage pipe part to the pump pipe of the reverse drainage, place the base plate at the bottom of the main rod frame of the device in the installation environment. After input through the drainage pipe and continuous discharge through the discharge pipe to maintain a connected state, during the process of discharging the reverse drainage fluid, the large-particle impurities in the reverse drainage fluid can be pre-treated and filtered through the connected filter cartridge part in cooperation with the internal grid filter layer. Subsequently, the user sets the collection time through the computer module and performs the collection operation once every thirty minutes. Then, the device is used to collect the reverse drainage fluid samples at regular intervals and record the collection time. By setting the initial time for the controller part of the device, during the initial rapid reverse drainage stage, collection is carried out once every thirty minutes. During collection, the controller controls the servo motor to drive, and the gear connected to the bottom end of the servo motor drives the engaged rack to transmit, causing the collection ring to rotate and align the insertion holes on the inner wall of the collection ring with the insertion cone heads. At the same time, the electric telescopic rod is controlled to push out, so that the structural plate connected to the end of the electric telescopic rod carries the telescopic tube to extend out together, and the insertion cone head at the end of the telescopic tube is inserted and connected to the insertion hole on the inner wall of the collection ring. Subsequently, the solenoid valve tube is controlled to open for collection. A part of the flowing reverse drainage fluid enters the collection needle through the solenoid valve tube and is injected into the sample tube through the collection needle to complete the collection. Then, the solenoid valve tube closes, and the collection ring rotates again to align the position of the insertion hole connected to the collected sample tube with the reagent valve tube. Through the telescopic drive of the reagent valve tube with the same structure, according to the pre-set injection volume that meets the requirements, the reagent in the reagent chamber is quantitatively injected into the sample tube. At this time, the sample tube is aligned with the spectrophotometer detection module up and down. The spectrophotometer detection module analyzes and monitors the changes in the concentration of suspended solids and proppants in the reverse drainage fluid. By using a continuous spectral light source, such as a tungsten lamp or a tungsten halogen lamp for the visible light region, and a hydrogen lamp or a deuterium lamp for the ultraviolet light region, by measuring the absorption intensity or absorbance of the reverse drainage fluid sample for light of a specific wavelength, combined with the Lambert-Beer law, the concentration or composition is calculated, and the information is transmitted to the computer module for processing. At the same time, the computer module can transmit the monitoring information in real time through the communication module. The user can pull out and replace the sample tube every day, collect the samples and add new sample tubes for subsequent collection operations. After the reverse drainage reaches a steady state, collection is carried out once every two hours, focusing on analyzing the content of dissolved salts and oils. The detected concentration information is transmitted to the laboratory in real time through the communication module of the collection device. The concentration curve is drawn based on the concentration detection results. Subsequently, the water production rate and the recovery rate are calculated by combining the concentration and the total amount of the reverse drainage fluid. Then, through laboratory adsorption tests, such as the adsorption rate of oil sand and crude oil to the tracer, the actual monitoring data is tested and corrected. After completion of the correction, parameters such as fracture length and conductivity are inferred by combining the characteristics of the flowback curve to optimize the subsequent fracturing design.Identify the fracturing fluid flowback rate through tracer monitoring, calculate the distribution of the fluid remaining in the formation that has not flowed back, estimate the effective fracture volume based on the total amount of tracer flowing back, distinguish the contributions of the main fractures, secondary fractures, and natural fractures by combining the tracer flowback sequence, analyze the change in fracture conductivity according to the correlation between the tracer flowback rate and the proppant distribution, and finally verify the tracer interpretation results by combining microseismic monitoring and distributed optical fiber temperature measurement data.

[0069] The above are only the preferred embodiments of the present invention and are not used to limit the present invention. For those skilled in the art, various modifications and changes can be made to the present invention. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. A detection and acquisition device for the distribution of fracturing fluid within shale fractures, characterized in that, Including: A main body mechanism, a valve pipe holder and a reagent valve pipe are connected to the outer side wall of the main body mechanism. The valve pipe holder is used for conveying a backflushing liquid sample, and the reagent valve pipe is used for injecting a color developing agent into the backflushing liquid sample; A collection mechanism, the collection mechanism is sleeved on a support mechanism, and the collection mechanism abuts against and communicates with the valve pipe holder; A support mechanism, the support mechanism is sleeved on the main body mechanism, and the support mechanism is rotatably connected to the main body mechanism. The support mechanism is fixedly connected to the collection mechanism, so that the collection mechanism is rotationally matched with the main body mechanism through the support mechanism; A detection mechanism, the detection mechanism is fixedly connected to the main body mechanism through a support arm. A spectrophotometer detection module is arranged on the detection mechanism and is used to cooperate with the collection mechanism and detect the absorbance of the backflushing liquid sample to light of a wavelength; A driving mechanism, the driving mechanism is arranged on the support arm, and the driving mechanism abuts against the collection mechanism and is used to control the rotation of the collection mechanism; Wherein, the main body mechanism includes a main rod frame, a discharge pipe is connected to the top end of the main rod frame, a base plate is connected to the low end of the main rod frame, a discharge pipe is also communicated with the bottom side wall of the main rod frame. Flanges are connected to the ends of the discharge pipe and the discharge pipe away from the main rod frame, and the discharge pipe and the discharge pipe are communicated with each other. A filter cylinder is detachably arranged in the discharge pipe, a mesh filter layer is connected to the inner wall of the filter cylinder, and the valve pipe holder is communicated with the discharge pipe; the collection mechanism includes a collection ring, racks are circumferentially arranged on the inner wall of the collection ring, a plurality of insertion holes are circumferentially and spaced apart on the inner wall of the collection ring, a plurality of sample accommodation components are circumferentially and spaced apart on the outer side wall of the collection ring, and the plurality of insertion holes correspond to and communicate with the plurality of sample accommodation components one by one; the sample accommodation component includes a collection needle, a connection pipe and a sample tube. The collection needle is connected to the outer side wall of the collection ring and is communicated with the insertion hole. The end of the collection needle away from the main rod frame is communicated with the connection pipe, the end of the connection pipe away from the collection needle is communicated with the sample tube, an outer rubber stopper is further arranged between the connection pipe and the collection needle, and a plurality of inner rubber stoppers are circumferentially arranged on the inner wall of the connection pipe.

2. The detection and acquisition device for the distribution of fracturing fluid in shale fractures according to claim 1, characterized in that, The support mechanism includes a bearing frame and a connecting frame. The bearing frame is sleeved and fixed on the main rod frame, and the connecting frame is fixedly connected to the bearing frame, so that the connecting frame is rotationally matched with the main rod frame. The collection mechanism is sleeved on the main rod frame, and the collection mechanism is fixedly connected to the connecting frame.

3. The fracturing fluid distribution detection and acquisition device in the shale fracture according to claim 1, characterized in that, The detection mechanism includes a housing, a computer module and the spectrophotometer detection module. The housing is located at the top of the support arm, the computer module is located in the housing, the spectrophotometer detection module is located at the bottom of the support arm, and the spectrophotometer detection module is electrically connected to the computer module. The spectrophotometer detection module is provided with a detection chamber for accommodating the sample tube.

4. The detection and acquisition device for the distribution of fracturing fluid in shale fractures according to claim 3, wherein The driving mechanism includes a servo motor, a gear, a controller, a power supply, and a communication module. The servo motor is embedded at the bottom of the support arm. The bottom end of the servo motor is electrically connected to the gear. The gear meshes with the rack. One side of the servo motor is also electrically connected to the controller. The power supply is located inside the housing. The communication module is located on one side of the power supply and is electrically connected to the power supply. Both the controller and the computer module are electrically connected to the power supply.

5. The detection and acquisition device for the distribution of fracturing fluid in shale fractures according to claim 1, wherein The valve pipe rack includes a solenoid valve pipe. One end of the solenoid valve pipe close to the main rod rack is communicated with an inner pipe. The inner pipe is communicated with the discharge pipe. One end of the solenoid valve pipe away from the inner pipe is communicated with a telescopic pipe. One end of the telescopic pipe away from the solenoid valve pipe is connected to a structural plate. An electric telescopic rod is connected to the inner wall of the structural plate. The electric telescopic rod is also connected to the solenoid valve pipe. A soft rubber pad is connected to the outer wall of the structural plate. A plugging cone head is connected to the middle of the soft rubber pad. The plugging cone head is communicated with the inner pipe through the telescopic pipe.

6. The fracture fluid distribution detection and acquisition device in shale fractures according to claim 1, wherein, A reagent chamber for accommodating the color developer is formed inside the main rod rack. The reagent valve pipe is communicated with the accommodating chamber.

7. A method for detecting the distribution points of fracturing fluid in shale fractures, including the shale fracture internal fracturing fluid distribution detection and acquisition device according to any one of the above claims 1-6, characterized in that It includes the following steps: S1. Fracturing fluid injection: According to the multi-stage fracturing division of the on-site environment, tracers with different concentrations are selected, and tracers with different labels are added to different fracturing sections of the fracturing fluid. S2. Reverse flow fluid collection: The detection and sampling device is arranged at the required sampling point. The discharge pipe is communicated with the reverse flow pump pipeline. The reverse flow fluid sample is regularly collected through the detection and sampling device, and the reverse flow volume at the time of collection is recorded. S3. Collection in time periods: By setting the initial time for the controller, collection is carried out once every thirty minutes in the initial rapid reverse flow stage to monitor the changes in the concentration of suspended solids and proppants in the reverse flow fluid. After the reverse flow reaches a steady state, collection is carried out once every two hours to analyze the content of dissolved salts and oils. S4. Data analysis and transmission: The concentration information detected by the collection device is transmitted to the laboratory in real time through the communication module. According to the concentration detection results transmitted by the collection device, the concentration values at each time point are sorted according to the sampling time to generate an original concentration scatter plot. The moving average method or polynomial fitting is used to eliminate random noise to obtain a continuous concentration change curve. S5. Dynamic data analysis: After the communication module transmits the concentration and collection volume information, the water production rate and recovery rate are calculated by combining the concentration and the total amount of reverse flow fluid. The adsorption rate of the oil sand and crude oil to the chemical tracer used in this time is obtained through laboratory adsorption tests. The actual concentration monitoring data is tested and corrected. The appearance sequence, concentration peak value, and attenuation law of each section of the tracer are monitored during the reverse flow stage, so as to quantitatively characterize the dynamic sequence of the fluid contribution of each layer section and obtain the tracer reverse flow sequence. S6. Monitoring result processing: Based on the characteristics of the concentration change curve, the fracture length and conductivity are inferred to optimize the subsequent fracturing design. Through the monitoring and identification of the reverse flow fracturing fluid by the tracer collection device and the recovery rate provided by the laboratory, the distribution of the un-reversed fluid retained in the formation is measured. S7. Data interpretation and modeling: Estimate the effective fracture volume based on the total amount of tracer backflow in the produced fluid obtained from this experiment. Combine the tracer backflow sequence to distinguish the main fractures, secondary fractures, and natural fractures. Analyze the change in fracture conductivity according to the tracer backflow rate and the effective fracture volume estimated from the total amount of tracer backflow. Combine the microseismic detection and distributed optical fiber temperature measurement data to verify the tracer detection results.

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