Downhole signal ball

Abstract

The utility model belongs to the technical field of signal acquisition, and particularly relates to an underground signal ball. The utility model provides an underground signal ball which can directly obtain actual pressure and temperature of a fracturing section. The device comprises a dissolvable hollow spherical shell, and is characterized in that a pressure sensor, a temperature sensor, a pressure transmitter, a temperature transmitter, a power supply, a controller and a memory ball are arranged in the hollow spherical shell, and a detection signal output port of the pressure sensor is connected with a detection signal input port of the controller through the pressure transmitter; a detection signal output port of the temperature sensor is connected with a detection signal input port of the controller through the temperature transmitter, an electric energy output port of the power supply is connected with a power supply port of the controller, and a signal transmission port of the controller is connected with the memory; a pressure guide hole is formed in the position, corresponding to the pressure sensor, of the hollow spherical shell.

Description

Technical Field

[0001] The utility model belongs to the technical field of signal collection, and in particular relates to an underground signal ball. Background Art

[0002] Downhole flowback technology has long been a hot topic of research. One of its core challenges is the heavy and bulky flowback material, which requires high flowback pressures. Currently, during fracturing operations, downhole pressure is typically estimated by collecting surface wellhead pressure. However, information such as the actual pressure and temperature in the fracturing section cannot be directly obtained. Utility Model Content

[0003] The utility model aims at solving the above problems and provides a downhole signal ball which can directly obtain the actual pressure and temperature of the fracturing section.

[0004] To achieve the above-mentioned purpose, the present invention adopts the following technical solution, which includes a soluble hollow spherical shell, characterized in that a pressure sensor, a temperature sensor, a pressure transmitter, a temperature transmitter, a power supply, a controller and a memory ball are arranged in the hollow spherical shell, the detection signal output port of the pressure sensor is connected to the detection signal input port of the controller through the pressure transmitter, the detection signal output port of the temperature sensor is connected to the detection signal input port of the controller through the temperature transmitter, the power output port of the power supply is connected to the power port of the controller, and the signal transmission port of the controller is connected to the memory; a pressure guide hole is provided on the hollow spherical shell at a position corresponding to the pressure sensor.

[0005] As a preferred solution, the soluble hollow spherical shell of the utility model adopts a soluble magnesium alloy shell.

[0006] As another preferred solution, the storage balls of the present invention are multiple.

[0007] As another preferred solution, the power source of the present invention adopts a battery.

[0008] As another preferred solution, the hollow spherical shell of the present invention includes an upper hemispherical shell and a lower hemispherical shell.

[0009] As another preferred embodiment, the utility model has four pressure sensors, one of which is arranged in the upper hemispherical shell pressure sensor placement groove in the middle of the upper hemispherical shell, the pressure sensor in the upper hemispherical shell is connected to the corresponding pressure transmitter in the upper hemispherical shell, the pressure transmitter in the upper hemispherical shell is arranged in the upper hemispherical shell pressure transmitter placement area on the outer periphery of the upper hemispherical shell pressure sensor placement groove, and the memory ball is arranged in the memory ball placement area on the outer periphery of the upper hemispherical shell pressure sensor placement groove;

[0010] The other three pressure sensors are evenly distributed along the circumference in the lower hemispherical shell pressure sensor placement groove. A pressure transmitter is correspondingly arranged on the outside of each pressure sensor arranged in the lower hemispherical shell; the lower hemispherical shell pressure transmitter is arranged in the lower hemispherical shell pressure transmitter placement groove above the corresponding lower hemispherical shell pressure sensor side; the middle part of the lower hemispherical shell is a battery placement groove.

[0011] As another preferred solution, the memory ball of the present invention includes an upper hemispherical shell and a lower hemispherical shell. A memory circuit board is located between the upper hemispherical shell and the lower hemispherical shell. The memory circuit board is connected to the annular circuit board via a soluble wire.

[0012] As another preferred solution, the soluble conductive wire of the present invention is a soluble magnesium alloy drawn wire.

[0013] As another preferred solution, the diameter of the storage ball of the present invention may be between 16.18 mm and 24.27 mm.

[0014] As another preferred solution, the inlet of the storage ball cage collector of the utility model can be connected to the wellhead through an inlet flange, and the outlet of the storage ball cage collector can be connected to the inlet of the blowout control valve through an outlet flange.

[0015] Secondly, the controller described in the present invention is arranged on a ring-shaped circuit board, and the pressure sensor interface, power input interface, and host computer debugging interface are arranged circumferentially on one side of the ring-shaped circuit board; the temperature sensor, controller, and storage ball interface are arranged circumferentially on the other side of the ring-shaped circuit board.

[0016] In addition, the upper hemispherical shell of the utility model is provided with an annular step for placing an annular circuit board, the lower hemispherical shell is provided with an annular boss for pressing the annular circuit board, and the inner wall of the upper hemispherical shell inside the annular boss is provided with a temperature sensor placement groove;

[0017] The annular circuit board is clamped between the annular step and the annular boss. The outer wall of the annular boss is provided with an external thread. The inner wall of the upper hemispherical shell outside the annular step is provided with an internal thread corresponding to the external thread of the outer wall of the annular boss.

[0018] The utility model has beneficial effects.

[0019] This utility model integrates a pressure ball body (a hollow spherical shell) with an information acquisition system (a pressure sensor, a temperature sensor, a pressure transmitter, a temperature transmitter, a power supply, a controller, and a memory ball) to form a complete signal ball structure. The pressure and temperature sensors collect fluid pressure above and below the signal ball and the ambient temperature. The data memory ball stores the collected pressure and temperature signals.

[0020] This utility model utilizes a dissolvable hollow spherical shell. Once a signal ball is dropped into the well, pressure and temperature signals are collected. Once the signal ball dissolves, the storage ball detaches and is discharged to the surface along with the sprayed liquid, where it is collected. The data collected by the storage ball is then read to directly determine the actual pressure and temperature of the fracturing section. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] The present invention will be further described below with reference to the accompanying drawings and specific embodiments. The scope of protection of the present invention is not limited to the following description.

[0022] Figure 1 This is an exploded view of the signal ball of the utility model.

[0023] Figure 1 In the figure, 1 is the upper hemispherical shell, 101 is the upper hemispherical shell pressure sensor placement groove, 102 is the memory ball placement area, 103 is the upper hemispherical shell pressure transmitter placement area, 104 is the annular step, 105 is the temperature sensor placement groove, 2 is the lower hemispherical shell, 201 is the lower hemispherical shell pressure transmitter placement groove, 202 is the lower hemispherical shell pressure sensor placement groove, 203 is the battery placement groove, 204 is the annular boss, 205 is the pressure guide hole, 3 is the annular circuit board, and 4 is the memory ball.

[0024] Figure 2 This is a system block diagram of the utility model.

[0025] Figure 3 It is a schematic diagram of the signal ball return process of the utility model.

[0026] Figure 4 This is a schematic diagram of a data storage ball circuit of the utility model.

[0027] Figure 5 This is a circuit schematic diagram of the power supply part of the utility model.

[0028] Figure 6 This is the circuit principle diagram of the single chip microcomputer and temperature collection part of the utility model.

[0029] Figure 7 This is the circuit principle diagram of the RS-485 communication and external interface part of the utility model.

[0030] Figure 8 This is a diagram of the signal acquisition circuit and interface definition of the ring circuit board of the utility model. DETAILED DESCRIPTION

[0031] As shown in the figure, the utility model includes a dissolvable hollow spherical shell, in which a pressure sensor, a temperature sensor, a pressure transmitter, a temperature transmitter, a power supply, a controller and a memory ball are arranged. The detection signal output port of the pressure sensor is connected to the detection signal input port of the controller through the pressure transmitter, the detection signal output port of the temperature sensor is connected to the detection signal input port of the controller through the temperature transmitter, the power output port of the power supply is connected to the power port of the controller, and the signal transmission port of the controller is connected to the memory; a pressure guide hole is provided on the hollow spherical shell at a position corresponding to the pressure sensor.

[0032] The soluble hollow spherical shell is made of a soluble magnesium alloy. Soluble magnesium alloy is a novel metal material composed primarily of magnesium, with other metal elements such as aluminum and zinc added through an alloying process. It boasts high strength, lightweight, corrosion resistance, and ease of processing, making it widely used in aviation, automotive, electronics, and oil and gas production.

[0033] The signal ball of the utility model can be used in conjunction with a soluble bridge plug to complete the fracturing work. The soluble bridge plug can adopt the soluble bridge plug with patent number 2019108891806 and the name "A full-metal soluble bridge plug". The working principle of fracturing is detailed in the content of the specific implementation method in this patent. The soluble hollow ball of the utility model acts as a fracturing ball; the soluble bridge plug is fixed at a certain position in the well and cooperates with the fracturing ball to realize the fracturing process. Existing fracturing balls can only play a plugging role and cannot collect pressure and temperature information during the fracturing process. The signal ball of the utility model can not only play a plugging role, but also collect pressure and temperature information of the entire fracturing process.

[0034] The utility model is a signal ball based on a fracturing soluble ball, which collects the upper and lower pressures of a sealing ball seat and the temperature of a sealing area.

[0035] The memory ball comprises an upper hemisphere shell and a lower hemisphere shell. A storage circuit board is located between the upper hemisphere shell and the lower hemisphere shell. The storage circuit board is connected to the annular circuit board via a soluble wire.

[0036] The soluble conductive wire is a soluble magnesium alloy drawn wire.

[0037] The diameter of the storage ball can be between 16.18 mm and 24.27 mm.

[0038] A storage ball cage collector can be installed. The cage's inlet is connected to the wellhead, and its outlet is connected to the blowout control valve inlet. A storage ball screen is installed at the cage's outlet. Flowback from the wellhead enters the cage. Flowback balls larger than the mesh size of the screen are discharged, while those smaller than the mesh size are retained in the cage.

[0039] The inlet of the storage ball cage collector can be connected to the wellhead through an inlet flange, and the outlet of the storage ball cage collector can be connected to the inlet of the blowout control valve through an outlet flange.

[0040] The acquisition time interval can be: during fracturing, a set of pressure and temperature is recorded every 1 second.

[0041] There are multiple storage balls.

[0042] The ball shell is made of soluble material. After being sealed in the well, it will gradually dissolve under the action of the fracturing fluid downhole. The sensor and the circuit, as well as the memory ball and the circuit board are connected by soluble wires, which will also dissolve and disconnect, leaving only the memory ball.

[0043] Once the soluble ball dissolves and ruptures, the signal storage ball is released, and the power supply, control chip, sensor, and circuit board are separated. After the flowback is collected in the storage ball, the signal data from the fracturing process is interpreted on the surface. The power supply and control chip are built into the circuit board, and the storage ball is connected to the circuit board via soluble wires. The pressure sensor is also connected to the circuit board via soluble wires. Once the wires fuse, the storage ball is separated. After separation, the sensor and circuit board are useless. Useful data has already been stored in the storage ball; it only needs to be retrieved and the stored data can be read.

[0044] The hollow spherical shell includes an upper hemispherical shell and a lower hemispherical shell.

[0045] There are four pressure sensors, one of which is arranged in the upper hemispherical shell pressure sensor placement groove in the middle of the upper hemispherical shell, the pressure sensor in the upper hemispherical shell is connected to the corresponding pressure transmitter in the upper hemispherical shell, the pressure transmitter in the upper hemispherical shell is arranged in the upper hemispherical shell pressure transmitter placement area on the outer periphery of the upper hemispherical shell pressure sensor placement groove, and the storage ball is arranged in the storage ball placement area on the outer periphery of the upper hemispherical shell pressure sensor placement groove;

[0046] The other three pressure sensors are evenly distributed along the circumference in the lower hemispherical shell pressure sensor placement groove. A pressure transmitter is correspondingly arranged on the outside of each pressure sensor arranged in the lower hemispherical shell; the lower hemispherical shell pressure transmitter is arranged in the lower hemispherical shell pressure transmitter placement groove above the corresponding lower hemispherical shell pressure sensor side; the middle part of the lower hemispherical shell is a battery placement groove.

[0047] The upper hemispherical shell pressure sensor placement groove and the lower hemispherical shell pressure sensor placement groove are cylindrical grooves; the lower hemispherical shell pressure transmitter placement groove and the battery placement groove are square grooves; the three lower hemispherical shell pressure sensor placement grooves are set at the three vertices of the same equilateral triangle.

[0048] The cylindrical slot is convenient for placing pressure sensors, while the square slot is convenient for placing pressure transmitters and batteries.

[0049] Four pressure sensors are used, with a vertex layout of a truncated regular tetrahedron inside a sphere, to ensure that the pressure above and below the soluble hollow spherical shell can be collected simultaneously in any direction of the ball seal.

[0050] The pressure sensor utilizes a truncated tetrahedron vertex layout within the sphere, ensuring simultaneous measurement of pressure above and below the soluble ball seat regardless of the ball setting orientation. This fully utilizes the spherical shell space to accommodate the pressure sensor, pressure transmitter, memory, annular circuit board, and battery. Small holes are provided at the four vertices of the hollow sphere housing to ensure contact between the pressure sensor's bearing surface and the pressure being measured. The temperature sensor is mounted close to the inner surface of the hollow sphere to ensure measurement of ambient temperature.

[0051] Four silicon piezoresistive pressure sensors sense pressure in all four directions on the signal ball. After conversion by a pressure transmitter, the pressure values are transmitted to the controller via RS-485. The controller integrates a digital temperature sensor to collect ambient temperature data and then stores the pressure and temperature data in three memory balls via an SPI interface. Both the pressure transmitter and the controller utilize low-power designs, ensuring the system meets storage time requirements even when powered by batteries.

[0052] The controller is mounted on a ring-shaped circuit board. One side of the circuit board is circumferentially arranged with interfaces for the pressure sensor, power input, and host computer debugging. The other side of the circuit board is also circumferentially arranged with interfaces for the temperature sensor, controller, and memory ball. The ring-shaped circuit board facilitates compatibility with the hollow spherical housing, facilitating wiring and battery placement.

[0053] The pressure sensor utilizes a silicon piezoresistive pressure sensor, particularly the HP10 model. The HP10 silicon piezoresistive pressure sensor utilizes a 316L stainless steel housing. Applied pressure is transmitted to the sensitive chip via a stainless steel diaphragm and internally sealed silicone oil. The sensitive chip does not directly contact the measured surface, resulting in a fully solid-state pressure measurement structure suitable for harsh, corrosive media environments. The pressure sensor converts pressure changes into resistance changes, and the pressure transmitter converts the resistance signal into a voltage signal. This signal is then converted to a digital signal via an analog analog converter (ADC) and output via RS-485.

[0054] The pressure transmitter communicates with the controller via RS-485.

[0055] The controller communicates with the memory ball via SPI.

[0056] The pressure transmitter is a V8L pressure transmitter manufactured by Nanjing Hangjia Electronic Technology Co., Ltd.

[0057] A W25Q128FV chip U1 is provided in the memory ball, and pins 1, 2, 5, and 6 of U1 are connected to CS, MISO, MOSI, and SCK respectively.

[0058] It can be calculated based on the amount of data stored per second: 4 pressure values and 1 temperature value. Both pressure and temperature are stored in single-precision format, occupying 4 bytes, 32 bits. The data stored per second occupies 32*5=160 bits. The storage time of a W25Q128FV is: 128000000 / 160=800000 seconds=222 hours.

[0059] The power supply uses TLV1117-33IDCYR module U4, with pin 3 of U4 connected to VIN (VIN is connected to the battery), and pins 2 and 4 of U4 connected to VDD_3.3V.

[0060] The controller adopts STM32L151CC chip U2, MAX3485EESA chip U3 and MAX3485EESA chip U5, and pins 12 to 17, 30, 31, 34, 38, 18, 20, 39, 21, 22 and 44 of U2 are respectively connected to PA2_4852C, PA3_SPI1_CS1, PA4_SPI1_CS2, PA5_SPI1_SCK, PA6_SPI1_MISO, PA7_SPI1_MISI, PA9_U1TX, PA10_U1RX, SWIO, SWCK, PA15_TEM, PB0_SPI1_CS3, ARM_BOOT1, PB3_4851C, PB10_U3TX, PB11_U3RX and ARM_BOOT0;

[0061] Pin 1 of U3 is connected to PB11_U3RX, pins 2 and 3 of U3 are connected to PA2_4852C, pin 4 of U3 is connected to PB10_U3TX, and pins 6 and 7 of U3 are connected to 4851A and 4851B respectively;

[0062] Pin 1 of U5 is connected to PA10_U1RX, pins 2 and 3 of U3 are connected to PB3_4851C, pin 4 of U5 is connected to PA9_U1TX, and pins 6 and 7 of U5 are connected to 4852A and 4852B respectively.

[0063] The STM32L151CC chip is a low-power single-chip microcomputer with two external RS-485 interfaces, one for collecting signals from four pressure sensors and one for soft communication with the host computer for debugging. It uses the SPI interface to communicate with three memory balls to store and read pressure and temperature data.

[0064] The temperature sensor uses a DS18B20 chip U1, with pin 2 of U1 connected to PA15_TEM. The DS18B20 digital temperature sensor is used to collect ambient temperature, with a temperature measurement accuracy of ±0.5°C and a temperature measurement range of -55°C to 125°C.

[0065] The controller communicates with the host computer via the RS-485 interface to initialize the controller configuration. The controller regularly collects pressure data from the four pressure sensors and temperature sensor data, and saves the collected pressure and temperature data to the memory ball for subsequent data reading and playback.

[0066] The controller uses an RS-485 communication interface to read data from four pressure sensors via the standard Modbus communication protocol. The controller reads the temperature values of the DS18B20 temperature sensor and the temperature value of the temperature sensor inside the controller chip, and stores the pressure and temperature data in three external memory balls using the SPI interface.

[0067] The working process of the present invention will be described below with reference to the accompanying drawings.

[0068] During fracturing, after the perforating tool string is retrieved from the surface, the signal ball is dropped into the wellhead. Before dropping the signal ball, the power supply is turned on and the data acquisition process is started. Simultaneously, the fracture interval information and the corresponding signal ball number are recorded.

[0069] After the signal ball dissolves underground, the information collection system is exposed, and the memory ball is separated from the circuit board and discharged to the surface along with the spray liquid. A ball cage collector is set up on the ground to collect the return solids.

[0070] After the surface collects the memory ball, the collected downhole information is read and the collected pressure and temperature data are displayed in lists and curves.

[0071] It can be understood that the above specific description of the present invention is only used to illustrate the present invention and is not limited to the technical solutions described in the embodiments of the present invention. Ordinary technicians in this field should understand that the present invention can still be modified or replaced by equivalents to achieve the same technical effects; as long as the use requirements are met, they are within the scope of protection of the present invention.

Claims

1. Downhole signal ball, including a soluble hollow spherical shell, characterized in that A pressure sensor, a temperature sensor, a pressure transmitter, a temperature transmitter, a power supply, a controller and a memory ball are arranged in the hollow spherical shell. The detection signal output port of the pressure sensor is connected to the detection signal input port of the controller through the pressure transmitter, the detection signal output port of the temperature sensor is connected to the detection signal input port of the controller through the temperature transmitter, the power output port of the power supply is connected to the power port of the controller, and the signal transmission port of the controller is connected to the memory; a pressure guide hole is arranged on the hollow spherical shell at the position corresponding to the pressure sensor.

2. The downhole signal ball according to claim 1, characterized in that The soluble hollow spherical shell is a soluble magnesium alloy shell.

3. The downhole signal ball according to claim 1, characterized in that There are multiple storage balls.

4. The downhole signal ball according to claim 1, characterized in that The hollow spherical shell includes an upper hemispherical shell and a lower hemispherical shell.

5. The downhole signal ball according to claim 1, characterized in that There are four pressure sensors, one of which is arranged in the upper hemispherical shell pressure sensor placement groove in the middle of the upper hemispherical shell, the pressure sensor in the upper hemispherical shell is connected to the corresponding pressure transmitter in the upper hemispherical shell, the pressure transmitter in the upper hemispherical shell is arranged in the upper hemispherical shell pressure transmitter placement area on the outer periphery of the upper hemispherical shell pressure sensor placement groove, and the storage ball is arranged in the storage ball placement area on the outer periphery of the upper hemispherical shell pressure sensor placement groove; The other three pressure sensors are evenly distributed along the circumference in the lower hemispherical shell pressure sensor placement groove. A pressure transmitter is correspondingly arranged on the outside of each pressure sensor arranged in the lower hemispherical shell; the lower hemispherical shell pressure transmitter is arranged in the lower hemispherical shell pressure transmitter placement groove above the corresponding lower hemispherical shell pressure sensor side; the middle part of the lower hemispherical shell is a battery placement groove.

6. The downhole signal ball according to claim 1, characterized in that The memory ball comprises an upper hemisphere shell and a lower hemisphere shell. A storage circuit board is located between the upper hemisphere shell and the lower hemisphere shell. The storage circuit board is connected to the annular circuit board via a soluble wire.

7. The downhole signal ball according to claim 6, characterized in that The soluble conductive wire is a soluble magnesium alloy drawn wire.

8. The downhole signal ball according to claim 1, characterized in that The diameter of the storage ball is between 16.18 mm and 24.27 mm.

9. The downhole signal ball according to claim 1, characterized in that The controller is arranged on an annular circuit board. A pressure sensor interface, a power input interface, and a host computer debugging interface are arranged circumferentially on one side of the annular circuit board; a temperature sensor, a controller, and a memory ball interface are arranged circumferentially on the other side of the annular circuit board.

10. The downhole signal ball according to claim 4, characterized in that The upper hemispherical shell is provided with an annular step for placing an annular circuit board, the lower hemispherical shell is provided with an annular boss for pressing the annular circuit board, and the inner wall of the upper hemispherical shell inside the annular boss is provided with a temperature sensor placement groove; The annular circuit board is clamped between the annular step and the annular boss. The outer wall of the annular boss is provided with an external thread. The inner wall of the upper hemispherical shell outside the annular step is provided with an internal thread corresponding to the external thread of the outer wall of the annular boss.

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