Detection and acquisition device and detection method for distribution of fracturing fluid in shale crack

Abstract

The invention relates to the technical field of shale gas exploitation, and provides a detection and collection device and detection method for distribution of fracturing fluid in shale fracture.The detection and collection device comprises a main body mechanism, a collection mechanism, a supporting mechanism, a detection mechanism and a driving mechanism; the specific concentration of a tracer agent is detected through controllable addition of a color developing agent and cooperation of a spectrophotometer detection module, automatic control collection detection is formed through setting of a computer and a controller, sample collection detection and real-time transmission can be completed without manual guarding and operation, and the detection efficiency is improved. And subsequent detection convenience and accuracy are provided for the distribution and retention condition of the fracturing fluid in the shale crack.

Description

Technical Field

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

[0002] In the process of shale gas extraction, injecting fracturing fluid into shale cracks is a key technical link. After the fracturing fluid is injected into the formation through a high-pressure pump, the pressure exerted on the rock exceeds its fracture strength, causing initial cracks in the shale. With continuous injection, the liquid pressure causes the original cracks to expand and connect with other natural or artificial cracks, eventually forming a complex network of crack systems, greatly improving the permeability of the reservoir. After the fracturing fluid is injected into the casing driven into the formation through the fracturing fluid technology, in order to maintain the quantitative analysis of the extraction process, the degree of crack opening and fluid distribution range of each fracturing layer section, and to determine the effective reservoir transformation area and main The contribution rate of the production layer is determined by monitoring the distribution of the fracturing fluid in the shale fractures. The existing technology mainly uses optical fiber sensing, microseismic monitoring technology and tracer technology to monitor the distribution of fracturing fluid. The tracer technology mainly includes radioactive tracer testing and chemical tracer monitoring. Since radioactive tracers contain radioactive substances, they are highly polluting to the environment. Therefore, most of them still use chemical tracer monitoring to monitor and process. Through the staged release method combined with the dynamic curve of the backflow fluid concentration, the difference in the distribution of fracturing fluid between the main fracture and the secondary fracture can be quickly identified to guide the optimization of the fracturing stage. The monitoring method for chemical tracers is mainly to mix the tracer into the fracturing fluid in a certain proportion during the fracturing construction process, and inject it into the casing together with the fracturing fluid. The backflow fluid samples are collected regularly during the backflow stage after fracturing, and the retention ratio of the fracturing fluid in the distal fracture or near-wellbore area is cross-verified by the backflow fluid composition and backflow curve characteristics combined with the fracture geometry of the fracture inclinometer data.

[0003] At present, in the initial rapid backflow stage of the backflow, it is necessary to collect and then test. During the collection, it is necessary to collect every 30 minutes at the collection point, and in 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 it is necessary to cooperate with time-periodic quantitative collection, and then cooperate with the detection instrument to carry out the detection operation. The collection volume and collection process are all manually operated, and there is uncertainty. In addition, it is necessary to stay near the collection point for a long time, and frequently turn over the collected samples within a 30-minute interval, and cooperate with the instrument to monitor the concentration of suspended matter and proppant, which consumes energy and time, affects the stability of long-term segmented collection and subsequent detection and use, and has certain disadvantages. Summary of the invention

[0004] 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.

[0005] 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.

[0006] In order to solve the above technical problems, the technical solution adopted in this application is: 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.

[0007] 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.

[0008] Furthermore, the above-mentioned main structure includes a main rod frame, the top of the main rod frame is connected to a discharge pipe, the lower end of the main rod frame is connected to a base plate, and the bottom side wall of the main rod frame is also connected to a discharge pipe. The discharge pipe and the discharge pipe are both connected to flanges at one end away from the main rod frame, and the discharge pipe and the discharge pipe are connected. A filter cartridge is detachably provided in the discharge pipe, and a mesh filter layer is connected to the inner wall of the filter cartridge. The valve pipe frame is connected to the discharge pipe, and the main rod frame is connected to the external pipeline through the discharge pipe and the discharge pipe to form a reverse discharge liquid flow channel. The filter cartridge and the mesh filter layer in the discharge pipe perform preliminary filtration on the reverse discharge liquid to remove suspended matter and large particle impurities so that the sample reaches the linear range of the spectrophotometer detection to avoid the absorbance exceeding the detection upper limit. The valve pipe frame is connected to the discharge pipe to transport the reverse discharge liquid sample, and the filter cartridge is detachable for easy cleaning and maintenance.

[0009] Furthermore, the above-mentioned supporting mechanism includes a bearing frame and a connecting frame. The bearing frame is sleeved and fixed on the main pole frame, and the connecting frame is fixedly connected to the bearing frame so that the connecting frame and the main pole frame can rotate together. The collecting mechanism is sleeved on the main pole frame, and the collecting mechanism is fixedly connected to the connecting frame. The bearing frame is sleeved and fixed on the main pole frame, and the connecting frame is connected to the bearing frame so that the connecting frame can rotate around the main pole frame. The collecting mechanism is fixedly connected to the connecting frame, thereby driving the collecting mechanism to rotate relative to the main mechanism through the rotation of the supporting mechanism, thereby realizing long-term interval collection.

[0010] Furthermore, the above-mentioned collection mechanism includes a collection ring, the inner wall of the collection ring is circumferentially provided with a rack, the inner wall of the collection ring is also circumferentially provided with a plurality of plug-in holes, the outer wall of the collection ring is circumferentially provided with a plurality of sample holding assemblies, the plurality of plug-in holes correspond one to one with and are connected to the plurality of sample holding assemblies, the plug-in holes on the collection ring are connected to the sample holding assemblies, the reverse discharge samples enter the sample holding assemblies through the plug-in holes, so as to realize the fixed-point collection of samples, and the rotation angle of the collection ring is precisely controlled by the rack transmission, so that the sample holding assemblies are aligned with the valve tube rack in turn, so as to realize the automatic switching collection of multiple samples, and can support the batch collection of reverse discharge samples in different time periods, improve the collection efficiency, and provide conditions for subsequent time period analysis.

[0011] Furthermore, the above-mentioned sample holding 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 the collection needle is connected to the plug-in hole. The end of the collection needle away from the main rod frame is connected to the docking tube, and the end of the docking tube away from the collection needle is connected to the sample tube. An outer rubber plug is also arranged between the docking tube and the collection needle, and a plurality of inner rubber plugs are arranged on the inner wall ring of the docking tube. The reverse discharge sample enters the docking tube through the collection needle, and the inner rubber plug on the inner wall of the docking tube and the outer rubber plug on the outside form a double seal. The inner rubber plug makes the sample tube and the collection needle tightly plugged to prevent sample leakage or external contamination. Finally, the sample flows into the sample tube for storage, thereby ensuring the integrity and purity of the sample, avoiding detection errors caused by contamination, and improving the accuracy of the detection results.

[0012] Furthermore, the sample tube is made of transparent material so that the sample tube meets the detection requirements under the spectrophotometer detection module.

[0013] Furthermore, the above-mentioned detection mechanism includes a shell, a computer module and a spectrophotometer detection module. The shell is located at the top of the support arm, the computer module is located in the shell, 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 cabin for accommodating a sample tube. The spectrophotometer detection module accommodates the sample tube through the detection cabin, and measures the absorbance of the sample to light of a specific wavelength by spectrophotometry. The computer module processes and analyzes the detection data in real time, establishes a corresponding relationship between the absorbance and the concentration of the sample component, realizes quantitative detection of the sample component, quickly obtains concentration data, improves the degree of automation and accuracy of the detection, and provides efficient data processing capabilities for real-time monitoring of fracturing fluid distribution.

[0014] Furthermore, 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 in the bottom of the bracket arm. The bottom end of the servo motor is electrically connected to a gear, and the gear is meshed with a rack. One side of the servo motor is also electrically connected to the controller. The power supply is located in the shell, and the communication module is located on one side of the power supply, and the communication module is electrically connected to the power supply. The controller and the computer module are both electrically connected to the power supply. The servo motor is meshed with the rack of the acquisition ring through the gear. The controller sends a signal to control the rotation of the servo motor, driving the acquisition ring to rotate precisely to the specified position. The power supply supplies power to each electronic component. The communication module realizes data transmission between the equipment and the external system, accurately controls the rotation angle and speed of the acquisition mechanism, realizes automatic positioning and acquisition actions, reduces manual operation errors, improves the stability and reliability of equipment operation, and supports remote control and real-time data transmission.

[0015] Furthermore, the valve tube rack includes an electromagnetic valve tube, an end of the electromagnetic valve tube close to the main rod rack is connected to an inner tube, the inner tube is connected to the discharge tube, an end of the electromagnetic valve tube away from the inner tube is connected to a telescopic tube, an end of the telescopic tube away from the electromagnetic valve tube is connected to a structural plate, an inner wall of the structural plate is connected to an electric telescopic rod, the electric telescopic rod is also connected to the electromagnetic valve tube, an outer wall of the structural plate is connected to a soft rubber pad, a middle part of the soft rubber pad is connected to a plug-in cone head, the plug-in cone head is connected to the inner tube through the telescopic tube, the electromagnetic valve tube is connected to the discharge tube through the inner tube, the electric telescopic rod adjusts the length of the telescopic tube so that the plug-in cone head can be inserted into the plug-in hole, thereby realizing precise injection of samples, and the soft rubber pad and the plug-in cone head ensure the sealing of the connection, thereby realizing automated sampling and transportation of samples.

[0016] Furthermore, a reagent chamber for accommodating a color developer is provided inside the main rod frame, and the reagent valve tube is connected to the accommodating chamber. The reagent valve tube is connected to the reagent chamber, and the color developer is transported to the sample to undergo a color development reaction with the tracer, which is convenient for subsequent spectral detection. The color developer storage function is integrated to simplify the pipeline connection, ensure the on-demand supply of the color developer, reduce the dependence on external reagent tanks, save equipment space, and improve operational convenience and system integration. The reagent valve tube has the same structure as the valve tube rack. After the valve tube rack injects the sample into the sample tube, the collection ring is rotated to dock with the reagent valve tube, and the color developer is injected into the sample by the reagent valve tube to complete the color development operation. The injection amount of the color developer is automatically controlled according to the detection requirements to ensure the accuracy of the color development reaction, realize the automatic addition of the color developer, avoid the tediousness and errors of manual operation, and improve the standardization of the detection process.

[0017] In the second aspect, the embodiment of the present application provides a method for detecting the distribution point of fracturing fluid in shale fractures, comprising the following steps: S1. Injection of fracturing fluid: select tracers of different concentrations according to the multi-stage fracturing distinction of the on-site environment, and add tracers with different identifications to different fracturing stages of the fracturing fluid; S2. Collection of backflow fluid: place the detection sampling device at the desired sampling point, connect the discharge pipe with the backflow pump pipeline, collect backflow fluid samples regularly through the detection sampling device, and record the backflow volume at the collection time; S3. Time-divided collection: set the controller to During the initial test, the data are collected every thirty minutes during the initial rapid backflow stage to monitor the changes in the proppant concentration in the suspended solids and backflow liquid. After the backflow reaches a steady state, the data are collected every two hours to analyze the soluble salt and oil content. S4. Data analysis and transmission: The concentration information detected by the acquisition 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 through the concentration detection results transmitted from the acquisition device to generate the 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 in combination with the concentration and the total amount of backflow liquid. The adsorption rate of the chemical tracer used in this experiment by oil sands and crude oil is obtained through laboratory adsorption tests. The actual concentration monitoring data is tested and corrected, and the appearance order, concentration peak and attenuation law of each section of the tracer are monitored during the backflow stage, so as to quantitatively characterize the dynamic sequence of the fluid contribution of each layer and obtain the tracer backflow sequence. ,S6. Monitoring result processing: Combine the characteristics of the concentration change curve to infer the fracture length and conductivity, Optimize the subsequent fracturing design, monitor and identify the backflow fracturing fluid through the tracer collection device and the recovery rate provided by the laboratory, calculate the distribution of the retained formation of the non-returned fluid, S7. Data interpretation and modeling: Estimate the effective fracture volume through the total amount of tracer backflow in the backflow fluid obtained in this experiment, distinguish between primary fractures, secondary fractures and natural fractures based on the tracer backflow sequence, and estimate the effective fracture volume based on the tracer backflow rate and the total amount of tracer backflow, analyze the changes in fracture conductivity, and verify the tracer detection results by combining microseismic detection and distributed optical fiber temperature measurement data.

[0018] Furthermore, in step S1, non-radioactive chemical tracers such as SCN or boron are selected, which need to have low adsorption, high stability and easy detectability to avoid adsorption interference with formation materials, and tracers with different labels are added 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 identification of the source of the flowback.

[0019] Furthermore, in step S3, it is necessary to use a color reaction method to cooperate with a specific reagent, thiocyanate color developer, and tracer to react to generate a colored substance. The reagent valve tube connected to the reagent chamber is connected to the sample tube after collection, and the thiocyanate color developer 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 interface calculates the concentration through absorbance in combination with the standard curve.

[0020] Furthermore, in step S7, special software or algorithms are required for auxiliary simulation. The software can use FracPredictor geological engineering integrated software, apply artificial intelligence nonlinear neural network technology, perform intelligent analysis on natural fracture modeling and fracturing simulation data, use MPM algorithm to simulate artificial fracturing effects, and support dynamic inversion of fracturing fluid return rate and fracture parameters. The algorithm realizes data visualization and multi-parameter comprehensive comparison through grey correlation analysis to improve analysis efficiency. The grey correlation analysis algorithm is used for multi-parameters, including correlation analysis between tracer concentration, return fluid volume, and fracture conductivity, to identify key factors affecting return dynamics, and to realize real-time collection and dynamic analysis of fracturing fluid return data through special software to improve operation efficiency. The Qt-based system can support cross-platform integration of tracer data with geological and engineering parameters to reduce human intervention errors. The MPM algorithm and artificial intelligence technology can simulate fracture extension paths and fracturing fluid retention risks to provide a basis for environmental assessment.

[0021] Compared with the prior art, the embodiments of the present invention have at least the following advantages or beneficial effects: 1. The collection ring of the rotating structure is connected with the reverse drainage pipeline to carry out periodic segmented collection and monitoring. With the controllable addition of the color developer in the reagent chamber, the sample can be tested for concentration through the spectrophotometer detection module to carry out periodic collection and detection process. The computer sets the time and the controller automatically controls each group of components to form an overall collection and detection module, thereby achieving the purpose of automatic segmented collection and detection. Sample collection, 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.

[0022] 2. During the discharge of the backwash liquid, the large particle impurities in the backwash liquid can be pre-treated and filtered through the connected filter cartridge part in cooperation with the internal mesh filter layer, thereby facilitating the subsequent sampling and detection process. At the same time, a reagent chamber is opened on one side of the inner wall of the main rod frame, which can be connected to the sample tube after collection through the reagent valve tube connected to the reagent chamber part, so that the thiocyanate color developer reacts with the tracer in the sample tube to generate a colored substance, which is convenient for subsequent concentration detection.

[0023] 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 backflow 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-developing agent, which reacts with the tracer in the tube to form a colored substance. At the same time, the sample tube is aligned with the spectrophotometer detection module for detection, saving subsequent laboratory steps, calculating the concentration with the standard curve, and further improving the detection efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] To more clearly illustrate the technical solutions of the embodiments of the present invention, the following will briefly introduce 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 relevant drawings can be obtained based on these drawings without creative efforts.

[0025] Figure 1 FIG. 1 is a schematic diagram of the overall structure of a device for detecting and collecting the distribution of fracturing fluid in shale fractures provided by the present invention; Figure 2 FIG. 2 is a schematic diagram of the internal structure of a device for detecting and collecting the distribution of fracturing fluid in shale fractures provided by the present invention; Figure 1 ; Figure 3 FIG. 3 is a schematic diagram of the internal structure of a device for detecting and collecting the distribution of fracturing fluid in shale fractures provided by the present invention; Figure 2 ; Figure 4 FIG. 4 is a schematic diagram of the valve pipe rack structure of a device for detecting and collecting the distribution of fracturing fluid in shale fractures provided by the present invention; Figure 5 FIG. 5 is a schematic diagram of the collection ring structure of a device for detecting and collecting the distribution of fracturing fluid in shale fractures provided by the present invention; Figure 1 ; Figure 6 FIG. 6 is a schematic diagram of the collection ring structure of a device for detecting and collecting the distribution of fracturing fluid in shale fractures provided by the present invention; Figure 2 ; Figure 7 FIG. 7 is a schematic diagram of the sample tube structure of a device for detecting and collecting the distribution of fracturing fluid in shale fractures provided by the present invention; Figure 8 FIG. 8 is a schematic diagram of the detection mechanism and the driving mechanism structure of a device for detecting and collecting the distribution of fracturing fluid in shale fractures provided by the present invention; Fig. 9 FIG. 9 is a schematic diagram of the flow of a method for detecting the distribution points of fracturing fluid in shale fractures provided by the present invention.

[0026] Icons: 1-main body; 101-main rod frame; 102-base plate; 103-inlet pipe; 104-outlet pipe; 105-flange; 106-reagent valve pipe; 107-reagent chamber; 108-filter cartridge; 109-grid 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-plug cone head; 3-collection Mechanism; 301-collection ring; 302-connection frame; 303-bearing frame; 304-rack; 305-plug hole; 306-collection needle; 307-sample tube; 308-butt tube; 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 DESCRIPTION

[0027] In order to make the purpose, 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 in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Generally, the components of the embodiments of the present invention described and shown in the drawings here can be arranged and designed in various different configurations.

[0028] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the invention claimed for protection, but merely represents selected embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0029] The features and performance of the present invention are further described in detail below in conjunction with the embodiments.

[0030] Embodiment 1: Please refer to Figure 1-8 , Figure 1 Shown is a schematic diagram of the overall structure of the present invention; Figure 2 The internal structure of the present invention is shown as follows Figure 1 ; Figure 3 The internal structure of the present invention is shown as follows Figure 2 ; Figure 4 The figure shows a schematic diagram of the valve pipe rack structure of the present invention; Figure 5 The structure of the acquisition ring of the present invention is shown as follows Figure 1 ; Figure 6 The structure of the acquisition ring of the present invention is shown as follows Figure 2 ; Figure 7 Shown is a schematic diagram of the sample tube structure of the present invention; Figure 8Shown is a schematic structural diagram of the detection mechanism and driving mechanism of the present invention.

[0031] like Figure 1-3 As shown, this embodiment provides a fracturing fluid distribution detection and collection device in shale fractures, including a main body mechanism, the outer side wall of the main body mechanism is connected with a valve pipe rack and a reagent valve pipe, the valve pipe rack is used to transport the backflow liquid sample, and 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 the supporting mechanism, and the collection mechanism abuts and is connected with 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, and the supporting mechanism is fixedly connected to the collection mechanism, so that the collection mechanism is rotatably 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, 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 wavelength light; 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.

[0032] like Figure 1-3 As shown, in the present embodiment, the main structure comprises a main rod frame, the top end of the main rod frame is connected to a discharge pipe, the lower end of the main rod frame is connected to a base plate, the bottom side wall of the main rod frame is also connected to a discharge pipe, the discharge pipe and the discharge pipe are connected to flanges at one end away from the main rod frame, and the discharge pipe is connected to the discharge pipe, a filter cartridge is detachably provided in the discharge pipe, a mesh filter layer is connected to the inner wall of the filter cartridge, and the valve pipe frame is connected to the discharge pipe.

[0033] like Figure 1-3 As shown, in this embodiment, the above-mentioned supporting 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 and the main rod frame can rotate together. The collecting mechanism is sleeved on the main rod frame, and the collecting mechanism is fixedly connected to the connecting frame.

[0034] like Figure 5-6 As shown, in this embodiment, the above-mentioned collection mechanism includes a collection ring, the inner wall of the collection ring is circumferentially provided with a rack, the inner wall of the collection ring is also circumferentially provided with a plurality of plug-in holes, and the outer wall of the collection ring is circumferentially provided with a plurality of sample holding components, and the plurality of plug-in holes correspond to and are connected with the plurality of sample holding components one by one.

[0035] like Figure 5-7 As shown, in this embodiment, the sample holding assembly 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 the collection needle is connected to the plug hole. The end of the collection needle away from the main rod frame is connected to the docking tube, and the end of the docking tube away from the collection needle is connected to the sample tube. An outer rubber plug is also arranged between the docking tube and the collection needle, and a plurality of inner rubber plugs are arranged on the inner wall ring of the docking tube.

[0036] like Figure 7-8 As shown, in this embodiment, the sample tube is made of transparent material so that the sample tube meets the detection requirements under the spectrophotometer detection module.

[0037] like Figure 8 As shown, in this embodiment, the above-mentioned detection mechanism includes a shell, a computer module and a spectrophotometer detection module, the shell is located at the top of the bracket arm, the computer module is located in the shell, the spectrophotometer detection module is located at the bottom of the bracket arm, and the spectrophotometer detection module is electrically connected to the computer module, and the spectrophotometer detection module is provided with a detection cabin for accommodating a sample tube.

[0038] like Figure 8 As shown, in this embodiment, the driving mechanism includes a servo motor, a gear, a controller, a power supply and a communication module. The servo motor is embedded in the bottom of the bracket arm. The bottom end of the servo motor is electrically connected to a gear, and the gear is meshed with the rack. One side of the servo motor is also electrically connected to the controller. The power supply is located in the shell, the communication module is located on one side of the power supply, and the communication module is electrically connected to the power supply. The controller and the computer module are both electrically connected to the power supply.

[0039] like Figure 4 As shown, in the present embodiment, the valve tube rack comprises an electromagnetic valve tube, one end of the electromagnetic valve tube close to the main rod rack is connected with an inner tube, the inner tube is connected with the discharge pipe, one end of the electromagnetic valve tube away from the inner tube is connected with a telescopic tube, one end of the telescopic tube away from the electromagnetic valve tube is connected with a structural plate, the inner wall of the structural plate is connected with an electric telescopic rod, the electric telescopic rod is also connected with the electromagnetic valve tube, the outer wall of the structural plate is connected with a soft rubber pad, the middle part of the soft rubber pad is connected with a plug-in cone head, and the plug-in cone head is connected with the inner tube through the telescopic tube.

[0040] like Figure 3 As shown, in this embodiment, a reagent chamber for accommodating a color developer is provided inside the main rod frame, and the reagent valve tube is connected to the accommodating chamber.

[0041] When the detection collection device is in use, it can be kept stably placed near the collection point by the base plate at the bottom of the main rod frame, and the discharge pipe and discharge pipe parts connected to the main rod frame are connected with flanges, which can be connected to the discharge pump through the discharge pipe to carry out connected discharge during the backflow process, and cooperate with the discharge pipe to discharge the backflow liquid to the treatment point without affecting the normal backflow of the fracturing fluid. During the backflow discharge process, the large particle impurities of the backflow liquid can be pre-treated and filtered through the connected filter cartridge part in cooperation with the internal grid filter layer, thereby providing convenience for the subsequent sampling and detection process. At the same time, a reagent chamber is opened on one side of the inner wall of the main rod frame, which can be connected to the sample tube after collection through a reagent valve tube connected to the reagent chamber part, so that the thiocyanate color developer reacts with the tracer in the sample tube to generate a colored substance, which is convenient for subsequent concentration detection.

[0042] When in use, the solenoid valve tube part mentioned above is electrically connected to the controller to maintain controllability, and can be opened and closed once every thirty minutes, so that the connected inner tube can collect the backflow liquid discharged from the main body mechanism. The electric telescopic rod can push the structural plate and the telescopic tube to extend, so as to cooperate with the plug-in cone head at the end of the telescopic tube to connect with the plug-in hole on the inner wall of the collection ring, so as to maintain a stable and controllable collection process.

[0043] When in use, the above-mentioned connecting frame connected around the bottom end of the collection ring can be connected and fixed to the outer wall around the bottom bearing frame to form a whole, and the bearing frame is fixed to the outer wall around the main rod frame, so that the collection ring can rotate with the main rod frame as the axis, and the rotation process of the collection ring is completely regulated by the servo motor. The controller can perform periodic servo motor regulation according to the set time, so that the servo motor controls the gear connected to the bottom to rotate, thereby forming friction with the meshing rack, so that the collection ring connected to the rack rotates along the axis of the main rod frame. According to the set time, the reverse drainage collection process can be performed every thirty minutes, thereby realizing automatic collection without the need for personnel supervision.

[0044] In the above-mentioned collection process, the collection ring can be connected with the valve tube rack or the reagent valve tube in sequence through the plug holes distributed on the inner wall of the collection ring, and the valve tube rack injects the back discharge liquid carrying the tracer and collects it in the connected sample tube. In the butt joint part, the inner rubber plug arranged on the inner wall and the outer rubber plug at the butt joint are combined to form a connection state, so as to maintain the sealing and stability during the collection process, and the reagent valve tube can be connected with the sample tube as the collection ring rotates, and the thiocyanate color developer is injected 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, and the sample tube is set in accordance with the pre-set The reagent in the reagent chamber is quantitatively injected into the sample tube. The reagent in the reagent chamber uses thiocyanate colorimetric agent. The principle is that nitrate ions react with specific colorimetric agent to generate colored substances. The absorbance is measured by spectrophotometer, and the concentration value is converted according to the standard curve. Thus, by using continuous spectrum light source, such as tungsten lamp and halogen tungsten lamp for visible light region, hydrogen lamp and deuterium lamp for ultraviolet light region, by measuring the absorption intensity or absorbance of the back-discharged liquid sample to light of specific wavelength, the concentration or composition is calculated in combination with Beer-Lambert's law, and then the aligned sample tube is tested to obtain the concentration data.

[0045] During the detection process, the concentration measurement data can be processed by the 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, so that the sample information of the time period can be provided at the first time. The computer sets the time and connects with the controller to form an automated control process for each group of components, achieving the purpose of segmented collection and detection. Sample collection 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.

[0046] Embodiment 2: Please refer to Fig. 9 , Fig. 9 Shown is a schematic diagram of the method flow of a method for detecting distribution points of fracturing fluid in shale fractures according to the present invention.

[0047] like Fig. 9 As shown, this embodiment provides a method for detecting the distribution points of fracturing fluid in shale fractures, comprising the following steps: S1. Fracturing fluid injection: According to the multi-stage fracturing of the field environment, if it is a multi-stage fracturing of a horizontal well, different concentrations of tracers are used in each stage. After the chemical tracer to be used is determined, tracers with different identifications are added to different fracturing stages of the fracturing fluid; S2. Collection of backflow liquid: Place a detection sampling device at the desired sampling point, connect the discharge pipe with the backflow pump pipe, collect backflow liquid samples regularly through the detection sampling device, and record the backflow volume at the collection time; S3. Time-divided sampling: By setting the initial test time on the controller, sampling is performed every 30 minutes in the initial rapid backflow stage to monitor the changes in the proppant concentration in the suspended solids and backflow liquid. After the backflow is steady, sampling is performed every two hours to analyze the soluble salt and oil content. S4. Data analysis and transmission: The concentration information detected by the acquisition device is transmitted to the laboratory in real time through the communication module. The concentration values ​​at each time point are sorted by sampling time based on the concentration detection results in the acquisition 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 transmitted concentration data and the total amount of backflow fluid data. Then, the adsorption rate of the tracer by oil sands and crude oil is obtained through laboratory adsorption tests, and the actual monitoring data is tested and corrected. The water production rate and recovery rate data are obtained by monitoring the different stages of the backflow fluid, such as the volume of the fracturing backflow fluid stage and the produced water stage, and the concentration of the indicators in the collected test tube, such as Cl⁻, TDS, suspended matter, etc. The critical point of the fracturing backflow fluid and the produced water is divided according to the concentration change, and the volume of the fracturing backflow fluid and the produced water volume are respectively counted to obtain the water production rate. Then, according to the total amount of the injected fracturing fluid in this experiment, the total amount of the backflow fluid after the complete collection is compared, and the recovery rate can be obtained. At the same time, the appearance order, concentration peak and attenuation law of each section of the tracer are monitored in the backflow stage, so as to quantitatively characterize the dynamic sequence of the fluid contribution of each layer and obtain the tracer backflow sequence; S6. Processing of monitoring results: Infer the fracture length and conductivity based on the characteristics of the concentration change curve, optimize the subsequent fracturing design, monitor and identify the backflow fracturing fluid through the tracer collection device and the recovery rate provided by the laboratory, and calculate the distribution of the retained formation of the non-flowback fluid; S7. Data interpretation and modeling: The effective fracture volume is estimated by the total amount of tracer flowback in the backflow fluid obtained from this experiment. Combined with the above tracer flowback sequence, primary fractures, secondary fractures and natural fractures are distinguished. The effective fracture volume is estimated based on the tracer flowback rate and the total amount of tracer flowback, and the changes in fracture conductivity are analyzed. The tracer detection results are verified by combining microseismic detection and distributed optical fiber temperature measurement data.

[0048] In summary, the present invention provides a detection and collection device and method for fracturing fluid distribution in shale fractures. When injecting fracturing fluid, the multi-stage fracturing is distinguished according to the on-site environment. If it is a multi-stage fracturing of a horizontal well, different concentrations of tracers are used in each stage. After determining the chemical tracer to be used, tracers with different labels are added to different fracturing stages of the fracturing fluid for backflow liquid collection. When this detection and collection device is installed, the discharge pipe part is first connected to the backflow pump pipeline, and the base plate at the bottom of the main rod frame of the device is placed with the installation environment. After input through the discharge pipe, it is continuously discharged through the discharge pipe to maintain the connected state. During the backflow liquid discharge process, the large particle impurities of the backflow liquid can be pre-treated and filtered through the connected filter cartridge part in cooperation with the internal mesh filter layer, and then used The operator sets the collection time through the computer module, and performs the collection operation every thirty minutes. Then, the device is used to collect the backflow liquid sample at a fixed time and record the collection time. By setting the initial time for the controller part of the device, the sample is collected every thirty minutes in the initial rapid backflow stage. During the collection, the controller controls the servo motor drive, and the gear connected to the bottom end of the servo motor drives the meshing rack to rotate the collection ring, and aligns the plug hole on the inner wall of the collection ring with the plug cone head. At the same time, the electric telescopic rod is controlled to be pushed out, so that the structural plate connected to the end of the electric telescopic rod extends out with the telescopic tube, so that the plug cone head at the end of the telescopic tube is connected to the plug hole on the inner wall of the collection ring. Then, the electromagnetic valve tube is controlled to be opened for collection, and a part of the circulating backflow liquid is discharged along with the plug hole. The electromagnetic valve tube enters the collection needle and is injected into the sample tube through the collection needle to complete the collection. Then the electromagnetic valve tube is closed, and the collection ring rotates again to align the position of the plug hole connected to the collected sample tube with the reagent valve tube. The reagent valve tube of the same structure is telescopically driven to quantitatively inject the reagent in the reagent cavity into the sample tube according to the injection volume set in advance. At this time, the sample tube is aligned with the spectrophotometer detection module up and down. The spectrophotometer detection module is used to analyze and monitor the changes in the concentration of the proppant in the suspended matter and the backwash liquid. By using a continuous spectrum light source, such as tungsten lamps and halogen tungsten lamps for the visible light region, hydrogen lamps and deuterium lamps for the ultraviolet light region, the absorption intensity or absorbance of the backwash liquid sample to a specific wavelength of light is measured, and the concentration or composition is calculated in combination with the Lambert-Beer law, and the information is converted into 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 the sample tube and replace it every day, collect the sample and add a new sample tube for subsequent collection operations. After the backflow is steady, the sample is collected every two hours, focusing on the analysis of soluble salts and oil content. 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 according to the concentration detection results, and then the water production rate and recovery rate are calculated in combination with the concentration and the total amount of backflow liquid. Then, through laboratory adsorption tests, such as the adsorption rate of oil sands and crude oil to tracers, the actual monitoring data is tested and corrected. After the correction is completed, the fracture length, conductivity and other parameters are inferred in combination with the characteristics of the backflow curve to optimize the subsequent fracturing design.The fracturing fluid return rate is identified through tracer monitoring, the distribution of the retained formation of the unreturned fluid is calculated, the effective fracture volume is estimated by the total tracer return volume, and the contribution of the main fracture, secondary fracture and natural fracture is distinguished by combining the tracer return sequence. The change of fracture conductivity is analyzed based on the correlation between the tracer return rate and the proppant distribution. Finally, the tracer interpretation results are verified by combining microseismic monitoring and distributed optical fiber temperature measurement data.

[0049] The above are only preferred embodiments of the present invention and are not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A device for detecting and collecting the distribution of fracturing fluid in shale fractures, characterized in that: include: A main body mechanism, the outer side wall of which is connected with a valve tube rack and a reagent valve tube, the valve tube rack is used to transport the backwash liquid sample, and the reagent valve tube is used to inject a color developer into the backwash liquid sample; A collecting mechanism, wherein the collecting mechanism is sleeved on the supporting mechanism and abuts against and communicates with the valve pipe rack; A support mechanism, wherein the support mechanism is sleeved on the main mechanism and is rotatably connected to the main mechanism, and the support mechanism is fixedly connected to the collection mechanism, so that the collection mechanism can be rotatably matched with the main mechanism through the support mechanism; A detection mechanism, wherein the detection mechanism is fixedly connected to the main mechanism via a support arm, and a spectrophotometer detection module is provided on the detection mechanism for cooperating with the collection mechanism and detecting the absorbance of the back-discharged liquid sample to wavelength light; A driving mechanism is arranged on the support arm and abuts against the collecting mechanism to control the rotation of the collecting mechanism.

2. A shale fracture fracturing fluid distribution detection and collection device according to claim 1, characterized in that: The main structure includes a main rod frame, the top end of the main rod frame is connected to a discharge pipe, the lower end of the main rod frame is connected to a base plate, and the bottom side wall of the main rod frame is also connected to a discharge pipe. The discharge pipe and the end of the discharge pipe away from the main rod frame are both connected to flanges, and the discharge pipe is connected to the discharge pipe. A filter cartridge is detachably provided in the discharge pipe, and a mesh filter layer is connected to the inner wall of the filter cartridge, and the valve pipe rack is connected to the discharge pipe.

3. A shale fracture fracturing fluid distribution detection and collection device according to claim 2, characterized in that: The supporting mechanism includes a bearing frame and a connecting frame. The bearing frame is sleeved and fixed on the main rod frame. The connecting frame is fixedly connected to the bearing frame so that the connecting frame and the main rod frame can rotate together. The collecting mechanism is sleeved on the main rod frame, and the collecting mechanism is fixedly connected to the connecting frame.

4. A shale fracture fracturing fluid distribution detection and collection device according to claim 3, characterized in that: The collection mechanism includes a collection ring, the inner wall of which is circumferentially provided with a rack, the inner wall of which is also circumferentially provided with a plurality of plug-in holes, the outer wall of which is circumferentially provided with a plurality of sample holding components, and the plurality of plug-in holes correspond one-to-one to and are connected with the plurality of sample holding components.

5. A shale fracture fracturing fluid distribution detection and collection device according to claim 4, characterized in that: The sample holding component includes a collection needle, a docking tube and a sample tube. The collection needle is connected to the outer side wall of the collection ring and is communicated with the plug hole. The end of the collection needle away from the main rod frame is communicated with the docking tube, and the end of the docking tube away from the collection needle is communicated with the sample tube. An outer rubber plug is also provided between the docking tube and the collection needle, and a plurality of inner rubber plugs are arranged on the inner wall ring of the docking tube.

6. A device for detecting and collecting the distribution of fracturing fluid in shale fractures according to claim 5, characterized in that: The detection mechanism includes a shell, a computer module and a spectrophotometer detection module. The shell is located at the top of the support arm, the computer module is located in the shell, 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 cabin for accommodating the sample tube.

7. A shale fracture fracturing fluid distribution detection and collection device according to claim 6, characterized in that: The driving mechanism includes a servo motor, a gear, a controller, a power supply and a communication module. The servo motor is embedded in the bottom of the bracket arm. The bottom end of the servo motor is electrically connected to the gear, and the gear is meshed with the rack. One side of the servo motor is also electrically connected to the controller. The power supply is located in the shell, and the communication module is located on one side of the power supply, and the communication module is electrically connected to the power supply. The controller and the computer module are both electrically connected to the power supply.

8. A shale fracture distribution detection and collection device according to claim 2, characterized in that: The valve pipe rack includes an electromagnetic valve pipe, one end of the electromagnetic valve pipe close to the main rod rack is connected to an inner pipe, the inner pipe is connected to the discharge pipe, the end of the electromagnetic valve pipe away from the inner pipe is connected to a telescopic pipe, the end of the telescopic pipe away from the electromagnetic valve pipe is connected to a structural plate, the inner wall of the structural plate is connected to an electric telescopic rod, the electric telescopic rod is also connected to the electromagnetic valve pipe, the outer wall of the structural plate is connected to a soft rubber pad, the middle part of the soft rubber pad is connected to a plug-in cone head, and the plug-in cone head is connected to the inner pipe through the telescopic tube.

9. A device for detecting and collecting the distribution of fracturing fluid in shale fractures according to claim 2, characterized in that: A reagent chamber for accommodating the developer is provided inside the main rod frame, and the reagent valve tube is communicated with the accommodating chamber.

10. A method for detecting distribution points of fracturing fluid in shale fractures, comprising the fracturing fluid distribution detection and collection device in shale fractures according to any one of claims 1 to 9, characterized in that: The following steps are involved: S1. Fracturing fluid injection: According to the multi-stage fracturing distinction of the on-site environment, select tracers of different concentrations and add tracers with different identifications to different fracturing stages of the fracturing fluid; S2. Backflow collection: Place the detection sampling device at the desired sampling point, connect the discharge pipe to the backflow pump pipe, collect backflow samples regularly through the detection sampling device, and record the backflow volume at the collection time; S3. Time-divided collection: by setting the initial test time for the controller, the data are collected every thirty minutes in the initial rapid backflow stage to monitor the changes in the proppant concentration in the suspended solids and backflow liquid. After the backflow is steady, the data are collected every two hours to analyze the soluble salt and oil content; S4. Data analysis and transmission: The concentration information detected by the acquisition device is transmitted to the laboratory in real time through the communication module. The concentration values ​​at each time point are sorted by sampling time based on the concentration detection results transmitted from the acquisition 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 in combination with the concentration and the total amount of backflow liquid. The adsorption rate of the chemical tracer used in this experiment by oil sands and crude oil is obtained through laboratory adsorption tests. The actual concentration monitoring data is tested and corrected. The appearance order, concentration peak and attenuation law of each section of the tracer are monitored during the backflow stage, so as to quantitatively characterize the dynamic sequence of the fluid contribution of each layer and obtain the tracer backflow sequence; S6. Processing of monitoring results: Infer the fracture length and conductivity based on the characteristics of the concentration change curve, optimize the subsequent fracturing design, monitor and identify the backflow fracturing fluid through the tracer collection device and the recovery rate provided by the laboratory, and calculate the distribution of the retained formation of the non-flowback fluid; S7. Data interpretation and modeling: The effective fracture volume is estimated by the total amount of tracer return in the backflow fluid obtained from this experiment. The primary fractures, secondary fractures and natural fractures are distinguished by combining the tracer return sequence. The effective fracture volume is estimated based on the tracer return rate and the total amount of tracer return, and the changes in fracture conductivity are analyzed. The tracer detection results are verified by combining microseismic detection and distributed optical fiber temperature measurement data.

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