Fracturing test device, system and method

Abstract

A fracturing test device, system and method, relating to the field of petroleum well logging. The fracturing test device is used for monitoring the status of each stratum of a fractured well. The fracturing test device comprises a housing (1) and a sensor (2) arranged in the housing (1); the outer surface of the housing (1) is coated with a soluble material layer; and the soluble material layer can be slowly degraded under the action of a fracturing fluid or a stratum-produced fluid, so that the density of the fracturing test device is reduced, and floats upwards under the buoyancy effect of the fracturing fluid or the stratum-produced fluid. The fracturing test device is used for being put into the fractured well to collect stratum data of each test stratum section of the fractured well; the density of the fracturing test device is changed by means of the soluble material layer, so as to ensure that the fracturing test device enters each test stratum section of the fractured well before fracturing; and by collecting the stratum data of each test stratum section by means of the fracturing test device, accurate analysis of a whole shaft can be achieved, thereby meeting requirements of fractured well test analysis.

Description

Fracturing test device, fracturing test system and method Technical Field

[0001] The present invention relates to the field of oil field testing, and in particular to a fracturing testing device, a fracturing testing system and a fracturing testing method. Background Art

[0002] Hydraulic fracturing is currently the primary method for developing low-permeability reservoirs and increasing production in conventional reservoirs. A correct understanding of the geometry, extension, and post-fracturing fluid production profile of hydraulic fractures plays a crucial role in evaluating fracturing effectiveness, improving fracturing design accuracy, optimizing development plans, and ultimately increasing individual well productivity.

[0003] Currently, oilfield development technicians use microseismic, tracer, production profile, and well testing methods to fully understand post-fracture fracture morphology and fracturing effectiveness. Microseismic methods require the deployment of a large number of geophones on the surface or underground, resulting in complex, time-consuming, and expensive construction. Existing conventional testing instruments capable of underground penetration are large, with limited access space. They must be lowered into the well with the tubing and then pulled out of the well after testing, requiring repeated operations and resulting in high costs. Furthermore, traditional testing methods only provide a general analysis of the entire wellbore and cannot meet the needs of fracture well testing analysis.

[0004] Summary of the Invention

[0005] In order to solve the above-mentioned technical defects, the present invention provides a fracturing test device, a fracturing test system and a method; the fracturing test device is small in size and can move in the fracturing string, and the outer surface of the shell of the fracturing test device is coated with a soluble material layer. The density of the fracturing test device is changed by the soluble material layer, which can ensure that it enters each test layer section of the fracturing well before fracturing, and returns to the fracturing wellhead with the return fluid after fracturing is completed. The operation is simple and the cost is low; the formation data of each test layer section is collected by the fracturing test device, which can realize accurate analysis of the entire wellbore and meet the needs of fracture test analysis.

[0006] A first aspect of the present invention provides a fracturing test device for monitoring formation conditions in a fracturing well, the fracturing test device comprising a housing and a sensor disposed within the housing, wherein the outer surface of the housing is coated with a soluble material layer;

[0007] The soluble material layer can slowly degrade under the action of the fracturing fluid or the formation fluid, so that the density of the fracturing test device becomes smaller and the device floats upward under the buoyancy of the fracturing fluid or the formation fluid;

[0008] The fracturing test device is used to be placed in a fracturing well to collect formation data of each test layer section of the fracturing well.

[0009] In an embodiment of the present invention, the fracturing testing device further includes a controller, which is disposed in the housing and electrically connected to the sensor for receiving formation data collected by the sensor.

[0010] In an embodiment of the present invention, the fracturing testing device further includes a battery, which is disposed in the housing and electrically connected to the sensor.

[0011] In an embodiment of the present invention, the diameter of the fracturing testing device is smaller than the diameter of the production fluid conveying pipe.

[0012] In the embodiment of the present invention, there are multiple sensors, and each sensor collects a type of formation data.

[0013] A second aspect of the present invention provides a fracturing test system, comprising: a fracturing test device and a catcher, wherein the fracturing test device is the fracturing test device described above;

[0014] The fracturing test device is placed in the fracturing well to collect formation data of each test layer section of the fracturing well;

[0015] The trap is used to capture the fracturing test device returned with the flowback fluid in the flowback fluid, and the flowback fluid includes fracturing fluid and formation production fluid.

[0016] In an embodiment of the present invention, the collector includes a main pipeline and a bypass pipeline. The bypass pipeline is connected to the main pipeline. The main pipeline is used to circulate the return fluid. A sorter is provided inside the main pipeline. The sorter is used to separate the fracturing test device from the return fluid and put it into the bypass pipeline.

[0017] In an embodiment of the present invention, the bypass channel includes:

[0018] a first bypass channel, provided at the upper portion of the main pipeline, for receiving light particulate matter having a density less than that of the flowback liquid;

[0019] The second bypass channel is provided at the lower portion of the main pipeline and is used for receiving heavy particulate matter having a density greater than that of the return fluid.

[0020] In an embodiment of the present invention, a first valve and a first particle collecting chamber are sequentially provided on the first bypass channel, and the first particle collecting chamber is used to collect the light particulate matter;

[0021] A second valve and a second particle collecting chamber are sequentially provided on the second bypass channel, and the second particle collecting chamber is used for collecting the heavy particulate matter.

[0022] In an embodiment of the present invention, the bypass pipe is a high-specific resistance channel, and the high-specific resistance channel is used to reduce the flow rate of the return fluid.

[0023] In an embodiment of the present invention, the trap further comprises a trap alarm, which is provided at the liquid inlet end of the main pipeline and is used to monitor the fracturing test device in the flowback fluid.

[0024] In an embodiment of the present invention, the fracturing test system further includes a soluble bridge plug, which is used to plug each test layer section of the fracturing well.

[0025] In an embodiment of the present invention, mounting holes are provided at both ends of the soluble bridge plug, and the mounting holes are used to install a fracturing test device, and the fracturing test device enters the fracturing well through the soluble bridge plug.

[0026] In an embodiment of the present invention, the fracturing test system also includes an analysis module, which is used to receive formation data of each test layer section of the fracturing well collected by sensors during the fracturing process, and analyze the fracturing effect of each test layer section based on the received formation data of each test layer section of the fracturing well during the fracturing process.

[0027] A third aspect of the present invention provides a fracturing test method, based on the above-mentioned fracturing test system, comprising:

[0028] Before the fracturing process, a test layer section of the fracturing well is obtained, a fracturing test device is sent into each test layer section through a fracturing string, and formation data of each test layer section before the fracturing process is collected by the fracturing test device;

[0029] During the fracturing process, the formation data of each test layer section in the fracturing process is collected by the fracturing testing device;

[0030] After the fracturing process, the formation data of each test layer section after the fracturing process is collected by the fracturing test device. After the collection is completed, the fracturing test device returns to the fracturing wellhead along with the return fluid.

[0031] In an embodiment of the present invention, the method further includes:

[0032] Before the fracturing process, the density of the fracturing fluid is obtained, and a soluble material layer is coated on the outer surface of the shell of the fracturing test device according to the density of the fracturing fluid, so that the density of the fracturing test device after the coating is completed is greater than the density of the fracturing fluid;

[0033] After the fracturing process, the soluble material dissolves in the flowback fluid, the density of the fracturing test device is lower than the density of the flowback fluid, and the fracturing test device returns to the fracturing wellhead along with the flowback fluid.

[0034] In an embodiment of the present invention, the step of sending the fracturing test device into each test layer through the fracturing string includes:

[0035] The fracturing fluid containing the fracturing test device is sequentially delivered to the test layer section through the fracturing string;

[0036] When the fracturing fluid fills each test interval, a soluble bridge plug is delivered to the current test interval, and the soluble bridge plug is used to block the current test interval.

[0037] In an embodiment of the present invention, the step of sending the fracturing test device into each test layer through the fracturing string includes:

[0038] delivering fracturing fluid to the test interval through the fracturing string;

[0039] When the fracturing fluid fills each test layer section, a soluble bridge plug is delivered to the current test layer section, and fracturing test devices are installed at both ends of the soluble bridge plug.

[0040] In an embodiment of the present invention, the method further includes:

[0041] After the fracturing process, the fracturing test device is captured by a catcher in the flowback fluid.

[0042] In an embodiment of the present invention, the fracturing testing device for capturing flowback fluid through a collector comprises:

[0043] The capture alarm of the capture device monitors the fracturing test device in the flowback fluid in real time;

[0044] The sorter in the catcher separates the fracturing test device into a bypass pipeline, which collects the fracturing test device.

[0045] The fracturing test device proposed in the present invention is small in size and can be moved in the fracturing string. The outer surface of the shell of the fracturing test device is coated with a soluble material. The density of the fracturing test device is changed by the soluble material, which can ensure that it enters each test layer section of the fracturing well before fracturing. After fracturing is completed, it returns to the fracturing wellhead with the return fluid. The operation is simple and the cost is low. By collecting the formation data of each test layer section through the fracturing test device, accurate analysis of the entire wellbore can be achieved, meeting the needs of fracture well test analysis.

[0046] Other features and advantages of the technical solution of the present invention will be described in detail in the specific implementation section below. BRIEF DESCRIPTION OF THE DRAWINGS

[0047] The drawings described herein are used to provide a further understanding of the present invention and constitute a part of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the drawings:

[0048] FIG1 is a schematic structural diagram of a fracturing testing device provided in an embodiment of the present invention;

[0049] FIG2 is a schematic structural diagram of a fracturing test system provided in an embodiment of the present invention;

[0050] FIG3 is a schematic structural diagram of a collector provided in an embodiment of the present invention;

[0051] FIG4 is a schematic structural diagram of a soluble bridge plug provided in an embodiment of the present invention;

[0052] FIG5 is a flow chart of a fracturing test method provided by an embodiment of the present invention;

[0053] FIG6 is a schematic diagram of a tubing string for a fracturing test method according to an embodiment of the present invention.

[0054] Description of Reference Numerals

[0055] 1-shell, 2-sensor, 3-controller, 4-battery, 5-mounting hole, 6-soluble bridge plug, 7-second valve, 8-sorter, 9-main pipeline inlet, 10-capture alarm, 11-bypass pipeline, 12-first valve, 13-first particle collecting chamber, 14-light particle sorter, 15-main pipeline outlet, 16-heavy particle sorter, 17-second particle collecting chamber, 18-soluble bridge plug FB, 19-soluble bridge plug FA, 20-fracturing test device group A, 21-fracturing test device group B, 22-fracturing test device group C, 23-formation YA section, 24-formation YB section, 25-formation YC section. DETAILED DESCRIPTION

[0056] To make the technical solutions and advantages of the embodiments of the present invention more clearly understood, exemplary embodiments of the present invention are further described in detail below with reference to the accompanying drawings. It should be noted that the embodiments described are only a portion of the embodiments of the present invention, and are not an exhaustive list of all embodiments. It should be noted that the embodiments of the present invention and the features thereof may be combined with each other unless they conflict.

[0057] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like to indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as limiting the present invention.

[0058] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of the technical features being referred to. Thus, a feature specified as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, "plurality" means at least two, such as two, three, etc., unless otherwise specifically defined.

[0059] In the present invention, unless otherwise expressly specified or limited, terms such as "mounted," "connected," "connect," and "fixed" should be understood broadly. For example, they may refer to fixed or detachable connections, or integration; mechanical or electrical connections, or communication; direct or indirect connections through an intermediate medium; and internal communication between two components or interaction between two components. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on specific circumstances.

[0060] During the development of this invention, the inventors discovered that hydraulic fracturing is currently the primary method for developing low-permeability reservoirs and increasing production in conventional reservoirs. A correct understanding of the geometry, extension, and post-fracturing fluid production profile of hydraulic fracturing fractures plays a crucial role in evaluating fracturing effectiveness, improving the accuracy of fracturing designs, optimizing development plans, and ultimately increasing single-well productivity.

[0061] Currently, oilfield development technicians use microseismic, tracer, production profile, well testing and other testing methods to fully understand the fracture morphology and fracturing effects after fracturing. Microseismic methods require the deployment of a large number of detectors on the surface or underground, resulting in complex construction processes, long cycles, and high costs. Existing ordinary testing instruments that can be lowered underground are large in size and have limited space. They need to be lowered into the well with the tubing and then pulled out with the tubing after the test is completed, requiring repeated operations and high costs. Furthermore, traditional testing methods can only perform a general analysis of the entire wellbore and cannot meet the needs of fracture well test analysis. For example, traditional well test pressure analysis and net pressure analysis can be used to interpret fractures. However, these well test pressure analysis and net pressure analysis technologies are affected by the fracturing process and cannot directly measure downhole pressure. Interpreting fractures through surface pump pressure lacks accuracy.

[0062] In response to the above problems, an embodiment of the present invention provides a fracturing test device, which enters each test layer section of a fracturing well through a fracturing string; the fracturing test device includes a shell and a sensor arranged in the shell, and the sensor is used to collect formation data of each test layer section of the fracturing well; the outer surface of the shell is coated with a soluble material so that the density of the fracturing test device is greater than the density of the fracturing fluid; the soluble material can be dissolved in the return fluid, and after the soluble material is dissolved, the density of the fracturing test device is less than the density of the return fluid; the diameter of the fracturing test device is smaller than the diameter of the fracturing string. The fracturing test device provided by the present invention is small in size and can be moved in the fracturing string. The outer surface of the shell of the fracturing test device is coated with a soluble material. The density of the fracturing test device is changed by the soluble material, so that it can enter the various test layers of the fracturing well before fracturing. After the fracturing is completed, it returns to the fracturing wellhead with the return fluid. The operation is simple and the cost is low. The formation data of each test layer is collected by the fracturing test device, so that the different fracturing sections of the fracturing well can be monitored and the formation parameters of each section can be analyzed and mastered.

[0063] Example 1

[0064] Figure 1 is a schematic diagram of the structure of a fracturing test device provided by an embodiment of the present invention. As shown in Figure 1, a fracturing test device provided by this embodiment is used to monitor the formation conditions of a fracturing well. The fracturing test device enters each test layer section of the fracturing well through a fracturing string;

[0065] The fracturing test device includes a housing 1 and a sensor 2 disposed in the housing 1, wherein the sensor 2 is used to collect formation data of each test layer section of the fracturing well;

[0066] The outer surface of the shell 1 is coated with a soluble material layer. The soluble material layer can slowly degrade under the action of the fracturing fluid or the formation fluid, thereby reducing the density of the fracturing test device and allowing it to float under the buoyancy of the fracturing fluid or the formation fluid, so that the density of the fracturing test device is greater than the density of the fracturing fluid. The soluble material layer can dissolve in the flowback fluid. After the soluble material dissolves, the density of the fracturing test device is less than the density of the flowback fluid.

[0067] The diameter of the fracturing test device is smaller than the diameter of the fracturing string. Furthermore, the diameter of the fracturing test device is at least three times smaller than the diameter of the fracturing string, which does not affect the flow of well fluid and is not likely to clog the wellbore. The fracturing test device is made of resin material, which is weaker than coiled tubing and does not cause wellbore sticking.

[0068] In this embodiment, the fracturing test device further includes a controller 3, which is disposed in the housing 1 and electrically connected to the sensor 2 for receiving formation data collected by the sensor 2. Specifically, the controller 3 is further configured to store the formation data collected by the sensor 2.

[0069] In this embodiment, the fracturing test device further includes a battery 4, which is disposed within the housing 1 and electrically connected to the sensor 2. The battery 4 is used to provide power to the sensor 2 and the controller 3. To further reduce the size of the fracturing test device, the battery 4 is a flexible battery.

[0070] Furthermore, the density of the instrument test circuit part inside the fracturing test device is lower than the density of the return fluid (the density of the return fluid is close to 1); the density of the electronic components of the test circuit, such as batteries, chips, etc., is greater than 1. By combining them with the circuit part using high-pressure resistant, low-density packaging materials, the density of the test instrument is reduced to less than 1; the density is less than 1, but close to 1, between 0.97 and 1; too low a density may cause the test device to be restricted in horizontal movement, because the smaller the density, the greater the vertical upward force remaining after the buoyancy overcomes gravity, and in the horizontal section, it is easy to hit the gap in the upper wall of the casing or the casing coupling and lose the ability to move freely.

[0071] To maintain the existing fracturing test process, after the fracturing test is completed, the flowback fluid is transported to a storage device via the production fluid delivery pipe. Therefore, in this embodiment, the diameter of the fracturing test device is smaller than the diameter of the production fluid delivery pipe. Furthermore, the production fluid delivery pipe is used to transport the flowback fluid, which includes fracturing fluid and formation production fluid. The production fluid delivery pipe includes a fracturing fluid delivery pipe and a production fluid delivery pipe. The fracturing fluid delivery pipe is used to transport fracturing fluid returned from the fracturing well, while the production fluid delivery pipe is used to transport formation production fluid.

[0072] In this embodiment, there are multiple sensors 2, each of which collects one type of formation data. The fracturing test device has multiple sensors, each of which collects one type of formation data, or multiple sensors cooperate to collect one type of data.

[0073] In order to ensure that the volume of the fracturing test device can pass through the fracturing string, in other embodiments of the present invention, each fracturing test device has only one sensor 2 for testing one type of formation data.

[0074] In other embodiments of the present invention, a plurality of sensors 2 cooperate to collect a type of formation data.

[0075] Furthermore, the formation data includes interval pressure, interval temperature and interval flow.

[0076] In this embodiment, the interval flow is calculated using triaxial acceleration and triaxial inclinometer data of the instrument.

[0077] The present invention configures a fracturing test device with high-density input and low-density discharge. A layer of soluble material coats the device, giving it a density slightly greater than that of the fracturing fluid. Under the action of the fracturing fluid and formation production fluid, the soluble material slowly degrades and eventually dissolves completely, reducing the density of the fracturing test device. Buoyancy allows the device to float to the wellhead for recovery.

[0078] Figure 2 is a schematic diagram of the structure of a fracturing test system provided by an embodiment of the present invention. As shown in Figure 2, the fracturing test system provided by this embodiment includes: a trap and the fracturing test device described above; the fracturing test device is deployed in a fracturing well to collect formation data of each test layer section of the fracturing well;

[0079] The trap is used to capture the fracturing test device returned with the flowback fluid in the flowback fluid, and the flowback fluid includes fracturing fluid and formation production fluid.

[0080] Figure 3 is a structural schematic diagram of the collector provided in an embodiment of the present invention. As shown in Figure 3, in this embodiment, the collector includes a main pipeline and a bypass pipeline 11. The bypass pipeline 11 is connected to the main pipeline. The main pipeline is used to circulate the return fluid. A sorter 8 is provided inside the main pipeline. The sorter 8 is used to separate the fracturing test device from the return fluid and put it into the bypass pipeline 11.

[0081] Specifically, the bypass pipeline 11 includes:

[0082] a first bypass channel, provided at the upper portion of the main pipeline, for receiving light particulate matter having a density less than that of the flowback liquid;

[0083] The second bypass channel is provided at the lower portion of the main pipeline and is used for receiving heavy particulate matter having a density greater than that of the return fluid.

[0084] Furthermore, the first bypass channel is provided with a first valve 12 and a first particle collecting chamber 13 in sequence, and the first particle collecting chamber 13 is used to collect the light particulate matter;

[0085] The second bypass channel is provided with a second valve 7 and a second particle collecting chamber 17 in sequence. The second particle collecting chamber 17 is used to collect the heavy particulate matter.

[0086] Specifically, a light particle separator 14 is located on the side of the first particle collection chamber 13 away from the first valve 12. This separator is used to retain light particles in the first particle collection chamber 13, while the remaining flowback fluid flows into the main pipeline. A heavy particle separator 16 is located on the side of the second particle collection chamber 17 away from the second valve 7. This separator is used to retain heavy particles in the second particle collection chamber 17, while the remaining flowback fluid flows into the main pipeline. The collector is also used to purify the flowback fluid.

[0087] In this embodiment, the bypass pipe 11 is a high-specific resistance channel, which is used to reduce the flow rate of the return fluid. Specifically, a partition is provided in the high-specific resistance channel, which is used to reduce the flow rate of the return fluid.

[0088] In this embodiment, the trap further includes a trap alarm 10 , which is provided at the liquid inlet end of the main pipeline. The trap alarm 10 is used to monitor the fracturing test device in the flowback fluid.

[0089] Specifically, the return fluid containing the fracturing test device enters the collector through the main pipeline inlet 9, flows out through the main pipeline outlet 15 and enters other processes. After the larger particles carried by the return fluid enter the main pipeline, they first pass through the capture alarm 10. When the capture alarm 10 detects the fracturing test device, it will alarm and indicate. The larger particles in the return fluid are separated by the sorter 8 of the main pipeline and enter the high-resistance channel. The high-resistance channel causes the fluid flow rate to decrease, which is conducive to the sedimentation or floating of the particles. Among them, heavy particles enter the second particle collection chamber 17, and light particles enter the first particle collection chamber 13. The heavy particle sorter 16 in the second particle collection chamber 17 intercepts the heavy particles in the second particle collection chamber 17, and the return fluid flows out into the main pipeline and flows out from the main pipeline outlet 15. The light particle sorter 14 in the first particle collection chamber 13 intercepts the light particles in the first particle collection chamber 13, and the return fluid flows out into the main pipeline and flows out from the main pipeline outlet 15. The fracturing test device is a light particle, so the first valve 12 can be closed to recycle the device. For heavy particles, the second valve 7 can be closed to recycle them.

[0090] FIG4 is a schematic structural diagram of a soluble bridge plug 6 provided in an embodiment of the present invention. As shown in FIG4 , in this embodiment, the fracturing test system further includes a soluble bridge plug 6 , which is used to plug each test layer section of the fracturing well.

[0091] In other embodiments of the present invention, mounting holes 5 are provided at both ends of the soluble bridge plug 6, and the mounting holes 5 are used to install a fracturing test device. The fracturing test device is coated with a layer of soluble material and embedded into both ends of the soluble bridge plug 6 for fixing, as shown in FIG4 . Before fracturing, the fracturing test device is lowered into the fracturing layer position along with the soluble bridge plug 6. At this time, the fracturing test device can collect formation data of different layers at both ends of the bridge plug. Under the action of the fracturing fluid and the formation production fluid, the soluble material of the fracturing test device and the soluble bridge plug 6 slowly degrade and eventually completely dissolve. The fracturing test device is freed from its restraints and floats to the wellhead under the action of buoyancy and is recovered. Specifically, in the horizontal section of the fracturing well, the fracturing test device moves by the carrying effect of the return fluid, and at the vertical end of the fracturing well, the fracturing test device moves back to the wellhead by the carrying effect of the return fluid and the action of buoyancy.

[0092] The fracturing test device is returned with the produced fluid (i.e., the flowback fluid). The fracturing test device itself is small in size and has a density slightly lower than that of the fracturing fluid. It is coated with a layer of soluble material, making its density slightly higher than that of the fracturing fluid. The soluble material can also be connected and fixed to the end of the soluble bridge plug 6 (such as a threaded connection). When the fracturing is completed and enters the flowback stage, the soluble material dissolves into the flowback fluid as the fracturing fluid and formation production fluid continue to erode. After the soluble material coating the fracturing test device disappears, its density decreases, and its volume is small enough to pass through the fracturing or production tubing space and be discharged to the wellhead along with the flowback fluid.

[0093] In this embodiment, the fracturing test system also includes an analysis module, which is used to receive the formation data of each test layer section of the fracturing well collected by the sensor 2 during the fracturing process, and analyze the fracturing effect of each test layer section based on the received formation data of each test layer section of the fracturing well during the fracturing process.

[0094] FIG5 is a flow chart of a fracturing test method provided by an embodiment of the present invention. As shown in FIG5 , the fracturing test method provided by this embodiment includes the following steps:

[0095] Before the fracturing process, a test layer section of the fracturing well is obtained, a fracturing test device is sent into each test layer section through a fracturing string, and formation data of each test layer section before the fracturing process is collected by the fracturing test device;

[0096] During the fracturing process, the formation data of each test layer section in the fracturing process is collected by the fracturing testing device;

[0097] After the fracturing process, the formation data of each test layer section after the fracturing process is collected by the fracturing test device. After the collection is completed, the fracturing test device is returned to the fracturing wellhead along with the return fluid;

[0098] Wherein, before the fracturing process, the density of the fracturing test device is greater than the density of the fracturing fluid; after the fracturing process, the density of the fracturing test device is less than the density of the flowback fluid.

[0099] In this embodiment, the method further includes:

[0100] Before the fracturing process, the density of the fracturing fluid is obtained, and a soluble material is coated on the outer surface of the housing 1 of the fracturing test device according to the density of the fracturing fluid. After the coating, the density of the fracturing test device is greater than the density of the fracturing fluid;

[0101] After the fracturing process, the soluble material dissolves in the flowback fluid, the density of the fracturing test device is lower than the density of the flowback fluid, and the fracturing test device returns to the fracturing wellhead along with the flowback fluid.

[0102] Specifically, in this embodiment, the fracturing test device is sent into each test layer through the fracturing string, including:

[0103] The fracturing fluid containing the fracturing test device is sequentially delivered to the test layer section through the fracturing string;

[0104] When the fracturing fluid fills each test layer interval, a soluble bridge plug 6 is delivered to the current test layer interval, and the soluble bridge plug 6 is used to block the current test layer interval.

[0105] In other embodiments of the present invention, the step of delivering the fracturing test device into each test layer through the fracturing string includes:

[0106] delivering fracturing fluid to the test interval through the fracturing string;

[0107] When the fracturing fluid fills each test layer section, a soluble bridge plug 6 is transported to the current test layer section. Fracturing test devices are installed at both ends of the soluble bridge plug 6.

[0108] In this embodiment, the method further includes:

[0109] After the fracturing process, the fracturing test device is captured by a catcher in the flowback fluid.

[0110] In an embodiment of the present invention, the fracturing testing device for capturing flowback fluid through a collector comprises:

[0111] The capture alarm 10 of the capture device monitors the fracturing test device in the flowback fluid in real time;

[0112] The sorter 8 in the catcher separates the fracturing test devices into the bypass pipe 11 , and the bypass pipe 11 collects the fracturing test devices.

[0113] Specifically, this embodiment provides a specific fracturing well testing process, which is as follows:

[0114] FIG6 is a schematic diagram of a tubing string for a fracturing test method according to an embodiment of the present invention. As shown in FIG6 , a horizontal fracturing well is designed to be fracturable in three stages, namely, formation YA stage 23 , formation YB stage 24 , and formation YC stage 25 .

[0115] According to the density of the fracturing fluid used in the design, the fracturing test device is coated with a soluble material to make its density greater than 1.2g / cm 3 Divide the fracturing test devices into three groups of four, numbering each and labeling the groups with the corresponding instrument numbers. The groups are designated as Fracturing Test Device Group A (20), Fracturing Test Device Group B (21), and Fracturing Test Device Group C (22). Program and activate the fracturing test devices.

[0116] During the operation, the fracturing test device A group 20 was pumped to the YA section 23 of the formation, and the fracturing string was lowered to fracture the YA section 23 of the formation. The fracturing test device A group 20 entered the YA section 23 of the formation along with the fracturing fluid. The soluble bridge plug FA19 was lowered to isolate the YA section 23 of the formation.

[0117] The operator pumped the fracturing test device B group 21 to the YB section 24 of the formation, and lowered the fracturing string to fracture the YB section 24. The fracturing test device B group 21 entered the YB section 24 of the formation along with the fracturing fluid. The soluble bridge plug FA19 was lowered to isolate the YB section 24 of the formation.

[0118] During operation, the fracturing test device C group 22 is pumped to the YC section 25 of the formation, and the fracturing string is lowered to fracture the YC section 25 of the formation. The fracturing test device C group 22 enters the YC section 25 of the formation along with the fracturing fluid.

[0119] After fracturing is complete, the well is shut down according to design requirements, followed by flowback. As the fracturing fluid and formation production fluid flow out of formation YC segment 25, the soluble metal coating of fracturing test device group C 22 gradually dissolves. The density of fracturing test device group C 22 decreases, and it begins to float upward, flowing with the flowback fluid to the wellhead and into the instrument trap. When the instrument passes the trap alarm 10, the alarm is triggered, notifying the operator to capture the fracturing test device. Over time, the soluble bridge plugs FB18 and FA19 also gradually dissolve, and the fracturing fluid and formation production fluid flow out of formation YB segment 24 and formation YA segment 23, accelerating the dissolution of the soluble metal coating of fracturing test device group B 21 and fracturing test device group A 20, reducing their density. The fracturing test device, with its reduced density, flows with the flowback fluid, floating through the pores of the dissolved soluble bridge plug 6, reaching the wellhead and entering the trap.

[0120] After the instrument is recovered, communication is established, and the data from the instrument is replayed. The data is grouped according to the instrument number and the recorded group. After data preprocessing, the fracturing effect is analyzed and evaluated using fracturing well testing software. The fracturing effect analysis includes fracturing process analysis, post-fracturing well obstruction analysis, and fracturing flowback process analysis.

[0121] Compared with the present invention and other existing technologies, the downhole temperature and pressure of each horizontal section of the staged fracturing is measured, which solves the technical problem of being unable to measure the formation breakdown pressure and the sealing performance of the bridge plug during the fracturing process, and provides a low-cost method for testing the output profile of the horizontal section of the fracturing well. In addition, no large equipment such as continuous oil pipes and cranes are required during the logging construction process, and low-cost monitoring is achieved without changing the fracturing construction process. The cost of testing a single section is low, and the cost is less than 5,000 yuan.

[0122] By technical comparison, the present invention realizes the actual measurement of downhole temperature and pressure of each horizontal section of the soluble bridge plug casing segmented fracturing, solves the technical problem of being unable to measure the formation breakdown pressure and bridge plug sealing during the fracturing process, and provides a low-cost horizontal well output profile testing method. In addition, no large equipment such as continuous oil pipes and cranes are required during the logging construction process, and low-cost monitoring is achieved without changing the fracturing construction process. The cost of a single section test is low, and the cost is less than 5,000 yuan.

[0123] The comparison between the present invention and the existing fracturing well formation condition monitoring technology is as follows:

[0124] Example 2

[0125] This embodiment is basically the same as the embodiment 1, except that the shell of the embodiment 2 is made of a soluble material, rather than the outer surface of the shell being coated with a soluble material layer as in the embodiment 1.

[0126] Furthermore, the soluble material is a soluble metal material.

[0127] In this embodiment, the sensor, controller and battery provided in the housing are all insulated and high temperature resistant to meet the pressure resistance requirements during the fracturing process.

[0128] In this embodiment, the diameter of the fracturing test device is smaller than the diameter of the fracturing string. Furthermore, when the fracturing test device is deployed into the various test layers of the fracturing well, the outer shell, made of soluble material, does not dissolve. Furthermore, when the fracturing test device is deployed into the various test layers of the fracturing well, the outer diameter of the fracturing test device is smaller than the inner diameter of the fracturing string. When the fracturing test device returns to the wellhead with the flowback fluid, it slowly degrades under the action of the fracturing fluid or formation fluid, leaving the outer shell behind. Consequently, the outer diameter of the fracturing test device is less than 40% of the inner diameter of the fracturing string.

[0129] Example 3

[0130] This embodiment is basically the same as embodiment 1. In this embodiment, the soluble material layer is a soluble metal material layer. Furthermore, the soluble metal material provided in this embodiment is a degradable fracturing magnesium alloy with a density of 1.82 g / cm 3 Its tensile strength is 305MPA, yield strength is 200MPA, elongation is 5.0%, dissolution environment is 90℃, 3%, dissolution rate is 40-60mg / cm 2 h.

[0131] Although the preferred embodiments of the present invention have been described, those skilled in the art may make additional changes and modifications to these embodiments once they have learned the basic creative concept. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments and all changes and modifications that fall within the scope of the present invention.

[0132] Obviously, those skilled in the art may make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if such changes and modifications fall within the scope of the claims and their equivalents, the present invention is intended to include such changes and modifications.

[0133] The above describes in detail the optional embodiments of the present invention in conjunction with the accompanying drawings. However, the embodiments of the present invention are not limited to the specific details in the above embodiments. Within the technical concept of the embodiments of the present invention, a variety of simple variations can be made to the technical solutions of the embodiments of the present invention, and these simple variations all fall within the scope of protection of the embodiments of the present invention. It should also be noted that the various specific technical features described in the above specific embodiments can be combined in any appropriate manner without contradiction, and as long as the combination does not violate the concept of the embodiments of the present invention, it should also be regarded as the content disclosed in the embodiments of the present invention.

Claims

1. A fracturing test device, used for monitoring the formation conditions of a fracturing well, characterized in that: The fracturing test device comprises a shell and a sensor disposed in the shell, wherein the outer surface of the shell is coated with a soluble material layer; The soluble material layer can be slowly degraded under the action of the fracturing fluid or the formation fluid, so that the density of the fracturing test device becomes smaller and the device floats up under the buoyancy of the fracturing fluid or the formation fluid; The fracturing test device is used to be placed in a fracturing well to collect formation data of each test layer section of the fracturing well.

2. The fracturing test device according to claim 1, characterized in that: The fracturing test device further includes a controller, which is disposed in the housing and is electrically connected to the sensor for receiving formation data collected by the sensor.

3. The fracturing test device according to claim 1, characterized in that: The fracturing testing device further includes a battery, which is disposed in the housing and is electrically connected to the sensor.

4. The fracturing test device according to claim 1, characterized in that: The diameter of the fracturing test device is smaller than the diameter of the production fluid conveying pipe.

5. The fracturing test device according to claim 1, characterized in that: There are multiple sensors, and each sensor collects a type of formation data.

6. A fracturing test system, characterized in that: include: A fracturing test device and a trap, wherein the fracturing test device is the fracturing test device according to claim 1; The fracturing test device is placed in a fracturing well to collect formation data of each test layer section of the fracturing well; The trap is used to capture the fracturing test device returned with the flowback fluid in the flowback fluid, and the flowback fluid includes fracturing fluid and formation production fluid.

7. The fracturing test system according to claim 6, characterized in that: The trap comprises a main pipeline and a bypass pipeline, wherein the bypass pipeline is connected to the main pipeline, the main pipeline is used for circulating the return fluid, and a sorter is arranged inside the main pipeline, and the sorter is used for separating the fracturing test device from the return fluid into the bypass pipeline.

8. The fracturing test system according to claim 7, characterized in that: The bypass pipeline comprises: A first bypass channel is provided at the upper portion of the main pipeline and is used to receive light particles having a density less than that of the flowback liquid; The second bypass channel is arranged at the lower part of the main pipeline and is used to receive heavy particles with a density greater than that of the return fluid.

9. The fracturing test system according to claim 8, characterized in that: The first bypass channel is provided with a first valve and a first particle collecting chamber in sequence, and the first particle collecting chamber is used to collect the light particulate matter; The second bypass channel is provided with a second valve and a second particle collecting chamber in sequence, and the second particle collecting chamber is used for collecting the heavy particulate matter.

10. The fracturing test system according to claim 7, characterized in that: The bypass pipeline is a high specific resistance channel, and the high specific resistance channel is used to reduce the flow rate of the return fluid.

11. The fracturing test system according to claim 7, characterized in that: The trap also includes a trap alarm, which is arranged at the liquid inlet end of the main pipeline and is used to monitor the fracturing test device in the return fluid.

12. The fracturing test system according to claim 6, characterized in that: The fracturing test system also includes a soluble bridge plug, which is used to plug each test layer section of the fracturing well.

13. The fracturing test system according to claim 12, characterized in that: Both ends of the soluble bridge plug are provided with mounting holes, and the mounting holes are used to install a fracturing test device, and the fracturing test device enters the fracturing well through the soluble bridge plug.

14. The fracturing test system according to claim 6, characterized in that: The fracturing test system also includes an analysis module, which is used to receive formation data of each test layer section of the fracturing well during the fracturing process collected by the sensor, and analyze the fracturing effect of each test layer section according to the received formation data of each test layer section of the fracturing well during the fracturing process.

15. A fracturing test method, based on the fracturing test system according to claim 6, characterized in that: The method comprises: Before the fracturing process, the test layer section of the fracturing well is obtained, and the fracturing test device is sent into each test layer section through the fracturing string, and the formation data of each test layer section before the fracturing process is collected by the fracturing test device; During the fracturing process, the formation data of each test layer section in the fracturing process is collected by the fracturing test device; After the fracturing process, the formation data of each test layer section after the fracturing process is collected by the fracturing test device. After the collection is completed, the fracturing test device returns to the fracturing wellhead along with the return fluid.

16. The fracturing test method according to claim 15, characterized in that: The method further comprises: Before the fracturing process, the density of the fracturing fluid is obtained, and a soluble material layer is coated on the outer surface of the shell of the fracturing test device according to the density of the fracturing fluid, and the density of the fracturing test device after coating is greater than the density of the fracturing fluid; After the fracturing process, the soluble material layer dissolves in the flowback fluid, the density of the fracturing test device is lower than the density of the flowback fluid, and the fracturing test device returns to the fracturing wellhead along with the flowback fluid.

17. The fracturing test method according to claim 15, characterized in that: The method of sending the fracturing test device into each test layer section through the fracturing pipe string includes: The fracturing fluid containing the fracturing test device is sequentially transported to the test layer section through the fracturing string; When the fracturing fluid fills each test layer interval, a soluble bridge plug is delivered to the current test layer interval, and the soluble bridge plug is used to block the current test layer interval.

18. The fracturing test method according to claim 15, characterized in that: The method of sending the fracturing test device into each test layer section through the fracturing pipe string includes: delivering fracturing fluid to the test layer section through the fracturing string; When the fracturing fluid fills each test layer section, a soluble bridge plug is delivered to the current test layer section, and fracturing test devices are installed at both ends of the soluble bridge plug.

19. The fracturing test method according to claim 15, characterized in that: The method further comprises: After the fracturing process, the fracturing test device in the flowback fluid is captured by the catcher.

20. The fracturing test method according to claim 19, characterized in that: The fracturing test device for capturing the flowback fluid through a collector comprises: The capture alarm in the capture tank monitors the fracturing test device in the flowback fluid in real time; The sorter in the catcher separates the fracturing test device into a bypass pipeline, and the fracturing test device is collected by the bypass pipeline.

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