Volume type underground gas flow accurate measuring device capable of self-generating electricity

Abstract

The utility model discloses a self-generating volumetric underground gas flow accurate measuring device which comprises an outer sleeve, a movable valve, a cylinder, a piston, a piston rod, a reversing block, an upper reversing connecting rod, a lower reversing connecting rod, a reversing rod, an inner sealing sleeve, a coil winding base body, an induction coil, an annular Halbach magnet array, a compression spring and the like. And the hardware circuit system is connected with the induction coil and the signal detection element. According to the device, pressure generated when gas is injected into a gas injection well is used for pushing a piston in a cylinder to do reciprocating motion, so that an induction coil on a piston rod is driven to cut magnetic induction lines, kinetic energy is converted into electric energy, and self-power-generation in the working process is achieved; compared with a traditional gas injection well flow measurement method, the gas flow measurement device can better adapt to the underground high-temperature and high-pressure environment, and measurement of micro flow is very sensitive and accurate.

Description

Technical Field

[0001] The utility model relates to the technical field of gas injection well equipment, in particular to a volumetric downhole gas flow precise measurement device capable of self-generating electricity. Background Technique

[0002] As the development of some oil fields in China enters the middle and late stages, the oil reservoirs generally enter the medium and high water cut periods. The development of remaining oil in old blocks of high water cut and low permeability reservoirs and the development of difficult-to-produce reservoirs such as heavy oil have become the key points for increasing reserves and production. Therefore, the research and application of gas injection flooding technology have also been paid more and more attention. At present, the main methods for measuring the flow rate of gas injection wells in oil fields are differential pressure method, vortex street method, ultrasonic method, etc. However, due to the complex downhole working conditions and harsh environment, the above flow measurement methods all have more or less problems such as insensitive measurement of small flow rates and being greatly affected by temperature and pressure.

[0003] Volumetric flow meters have the advantages of high measurement accuracy, wide measurement range, less affected by the environment, clear flow calculation, etc., and are widely used in the flow measurement of media such as natural gas, liquefied petroleum gas, crude oil, and diesel. However, in the use of downhole volumetric flow meters, power needs to be provided to devices such as signal detection elements and hardware circuits. The electric energy provided by simply using battery power supply is limited, cannot provide continuous and stable power supply, and is also easily damaged in high-temperature and high-pressure environments and needs to be frequently replaced, resulting in a relatively high equipment maintenance cost.

[0004] To solve the above technical problems, this application proposes a precise measurement device for downhole volumetric gas flow capable of self-generating electricity. Content of the Utility Model

[0005] The purpose of the utility model is to provide a precise measurement device for downhole volumetric gas flow capable of self-generating electricity to solve the above technical problems.

[0006] To solve the above technical problems, a precise measurement device for downhole volumetric gas flow capable of self-generating electricity provided by the utility model includes a movable valve, a proximity switch, a cylinder, a commutation block, a piston rod, an inner sealing sleeve, an annular Halbach magnet array, a compression spring, an outer sleeve, a piston, a commutation rod, a pressure sensor, an upper commutation connecting rod, a lower commutation connecting rod, a coil winding matrix, an induction coil, a temperature sensor, a middle exhaust hole, a left end air hole, a right end air hole, and also includes a hardware circuit system connected to the induction coil and signal detection elements;

[0007] The outer sleeve is of a cylindrical structure, and its thick end and thin end are respectively connected between two sections of oil pipes;

[0008] The inner sealed sleeve is installed inside the outer sleeve, and the piston rod inlets and outlets at both ends are sealed by sealing rings, forming a closed space independently for placing the annular Halbach magnet array, induction coil and compression spring;

[0009] The moving valve is a cylindrical structure with a hollow lower part. The middle exhaust hole connects the lower space of the moving valve with the outside. The left end air hole is directly connected to the rodless cavity of the cylinder, and the right end air hole is connected to the rod cavity of the cylinder through an external pipeline;

[0010] The cylinder is a cylindrical structure, used for temporarily storing gas and guiding the piston to perform linear reciprocating motion inside the cylinder;

[0011] The axial section of the piston is an H-shaped structure, which can increase the contact area between the piston and the inner wall of the cylinder, thereby reducing the gas leakage and preventing the piston from shifting or jamming during movement. In addition, the design of the upper and lower hollow parts can minimize the self-weight of the piston while ensuring sufficient contact area;

[0012] The piston rod is a cylindrical structure, its top is connected to the piston, a commutation block is installed in the middle part, and several cuboid-shaped coil winding bases are installed in the lower part. Induction coils are wound on the coil winding bases;

[0013] The compression spring is sleeved on the outermost end of the piston rod, used to balance the total gravity of the piston rod and all the components installed on the piston rod and reduce the inertial force generated by the reciprocating motion;

[0014] There are two proximity switches and two pressure sensors respectively, installed at the top and bottom of the cylinder, and the temperature sensor is installed on the inner wall of the outer sleeve.

[0015] Preferably, two coil winding bases are installed at the same height in the lower part of the piston rod, distributed in the left and right directions of the piston rod. A total of ten coil winding bases in five groups can be installed at the lower end of the entire piston rod. The middle distance between each adjacent two groups of coil winding bases is equal. A number of induction coils are evenly wound on each coil winding base, and the middle distance between the upper and lower sides of the induction coil is equal to half of the middle distance between adjacent two groups of coil winding bases.

[0016] Preferably, the annular Halbach magnet array is embedded in the inner wall of the inner sealed sleeve, its height is equal to the middle distance between the upper and lower sides of the induction coil. The same group of annular Halbach magnet arrays is at the same height and is composed of 12 magnets with different magnetization directions. A total of 18 groups of annular Halbach magnet arrays are arranged and installed in the inner sealed sleeve without gaps in sequence. The internal magnetic fields generated by two adjacent groups of annular Halbach magnet arrays are equal in magnitude, parallel and opposite in direction, and perpendicular to the upper and lower sides of the induction coil.

[0017] Preferably, the volumes of the rod chamber and the rodless chamber of the cylinder are fixed values, that is, the volume of the gas discharged under the working conditions in each stroke of the piston is fixed. According to the temperature and pressure data measured by the pressure sensor and the temperature sensor in each stroke, the single-chip microcomputer can perform temperature and pressure compensation on the fixed volume of the gas discharged from the cylinder in each stroke, convert it into the volume of the gas under standard conditions, add up the volumes of the gas under standard conditions calculated in each stroke, obtain the total volume of the gas injected within a period of time, and calculate the ratio of the total volume to the time by the single-chip microcomputer every once in a while, then the average gas flow rate value within this period of time can be obtained.

[0018] Preferably, the hardware circuit system includes a main control circuit, a rectifier voltage stabilization / voltage division circuit, an energy storage circuit, a storage circuit, and a signal conditioning circuit; the rectifier voltage stabilization / voltage division circuit is connected to the induction coil, converts the alternating current generated by the induction coil into direct current, supplies a part to the energy storage circuit for energy storage, and supplies the other part to the subsequent circuits; the signal detection element is connected to the signal conditioning circuit and the main control circuit, processes the measured temperature and pressure signals, and transmits them to the single-chip microcomputer for flow calculation.

[0019] Compared with the prior art, the utility model provides a precise measurement device for downhole volumetric gas flow that can generate electricity by itself, and has the following beneficial effects:

[0020] 1. For this utility model, by using the pressure generated when the gas is blocked by the device when the ground injects gas into the gas injection well, the piston is pushed to make a reciprocating linear motion in the cylinder, thereby driving the induction coil on the piston rod to cut the magnetic induction line in the magnetic field, converting this kinetic energy into electrical energy, and supplying power to the signal detection element and the hardware circuit system, avoiding frequent battery replacement and ensuring stable operation underground for a long time.

[0021] 2. For this utility model, by using the invariability of the gas volume discharged under the working conditions in each stroke of the cylinder, the gas volume under standard conditions is obtained through temperature and pressure compensation, and then the gas flow rate is calculated. Compared with other common gas flow measurement methods for gas injection wells, it can better adapt to the high-temperature and high-pressure environment underground, and the lower limit of flow measurement is very low, and it is also very sensitive and accurate for the measurement of micro flow rates. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 It is an axial sectional view of the overall structure of the utility model;

[0023] Figure 2 It is an axial sectional view of the moving valve and gas channel structure of the utility model;

[0024] Figure 3 It is a schematic diagram of the magnetic field direction of the annular Halbach magnet array of the utility model;

[0025] Figure 4 Partial schematic diagram of the annular Halbach magnet array and induction coil structure of the present utility model;

[0026] Figure 5 Schematic diagram of the overall circuit structure of the present utility model.

[0027] In the figure: 1, moving valve; 2, proximity switch; 3, cylinder; 4, commutation block; 5, piston rod; 6, inner sealing sleeve; 7, annular Halbach magnet array; 8, compression spring; 9, outer sleeve; 10, piston; 11, commutation rod; 12, pressure sensor; 13, upper commutation connecting rod; 14, lower commutation connecting rod; 15, coil winding matrix; 16, induction coil; 17, temperature sensor; 18, middle exhaust hole; 19, left end air hole; 20, right end air hole; 21, main control circuit; 22, rectification, voltage regulation / voltage division circuit; 23, energy storage circuit; 24, storage circuit; 25, signal conditioning circuit; 26, signal detection element. Specific embodiments

[0028] The specific embodiments of the present utility model will be further described below with reference to the accompanying drawings.

[0029] The present utility model includes a mechanical component and a measuring component, wherein the mechanical component is fixed between two sections of oil pipes underground. The gas injected on the ground first enters the rod chamber of the cylinder 3 through the right end air hole 20, and the pressure of the gas pushes the piston 10 to move upward; when the piston 10 moves to the topmost position, the commutation block 4 contacts and collides with the upper commutation connecting rod 13, thereby driving the commutation rod 11 to move downward, and finally pulling the moving valve 1 to translate to the rightmost end. The hollow space at its lower part connects the middle exhaust hole 18 and the right end air hole 20 to form an exhaust passage, and the left end air hole 19 becomes an intake passage to realize the commutation of the gas. At the same time, the proximity switch 2 installed at the top of the cylinder 3 outputs a high level to the single-chip microcomputer pin. After receiving the signal, the single-chip microcomputer pin collects and stores the temperature and pressure signals measured by the temperature sensor 17 and the pressure sensor 12 installed at the bottom of the cylinder, so as to prepare for calculating the volume of the gas discharged under standard conditions in the next stroke.

[0030] When the piston 10 moves to the bottommost position, the commutation block 4 comes into contact and collision with the lower commutation connecting rod 14, thereby driving the commutation rod 11 to move upward, and finally pushing the movable valve 1 to translate to the leftmost end, so that the middle exhaust hole 18 and the left end air hole 19 form an exhaust passage, and the right end air hole 20 becomes an intake passage, realizing commutation again. At the same time, the proximity switch 2 installed at the bottom end of the cylinder 3 outputs a high level to the single-chip microcomputer pin. After receiving the signal, the single-chip microcomputer pin collects and stores the temperature and pressure signals measured by the temperature sensor 17 and the pressure sensor 12 installed at the top of the cylinder at this time, and compensates the temperature and pressure of the gas volume in the just-discharged working condition according to the temperature and pressure data measured last time and the volume of the rodless cavity, to obtain the gas volume under standard conditions.

[0031] While the piston 10 makes a reciprocating linear motion, it drives the induction coil 16 on the piston rod 5 to make an up-and-down reciprocating motion of cutting magnetic induction lines in the internal magnetic field generated by the annular Halbach magnet array 7, converting kinetic energy into electrical energy. Since the height of the annular Halbach magnet array 7 is equal to the mid-distance between the upper and lower sides of the induction coil 16, as long as the induction coil 16 makes an up-and-down motion, the upper and lower sides of the induction coil 16 will simultaneously cut magnetic induction lines with equal magnitudes and opposite directions, thereby generating a series voltage source. The hardware circuit system rectifies, stabilizes the voltage and stores the electrical energy generated by the induction coil 16, and processes the temperature and pressure signals measured by the sensor, and transmits them to the single-chip microcomputer for flow calculation.

[0032] The overall structure of the present utility model includes: a movable valve 1, a proximity switch 2, a cylinder 3, a commutation block 4, a piston rod 5, an inner sealing sleeve 6, an annular Halbach magnet array 7, a compression spring 8, an outer sleeve 9, a piston 10, a commutation rod 11, a pressure sensor 12, an upper commutation connecting rod 13, a lower commutation connecting rod 14, a coil winding matrix 15, an induction coil 16, a temperature sensor 17, a middle exhaust hole 18, a left end air hole 19, a right end air hole 20, as specifically Figure 1 shown.

[0033] The movable valve 1 is a cylindrical structure with a hollow lower half; one end of the middle exhaust hole 18 is always communicated with the lower space of the movable valve 1, and the other end is directly communicated with the outside; the left end air hole 19 is directly communicated with the rodless cavity of the cylinder 3, and the right end air hole 20 is communicated with the rodless cavity of the cylinder 3 through a pipeline; the movable valve 1 makes the middle exhaust hole 18 establish an exhaust passage with the left end air hole 19 or the right end air hole 20 respectively at the alternating nodes of the up and down strokes by left and right translation, and at this time the other unselected air hole becomes an intake passage, and the specific structure is as Figure 2 shown.

[0034] The entire internal magnetic field generated by the annular Halbach magnet array 7 completely covers the movement range of the up-and-down stroke of the induction coil 16, and the direction of the internal magnetic field is perpendicular to the upper and lower sides and the movement direction of the induction coil 16. The upper and lower sides simultaneously cut the magnetic induction lines with equal magnitudes and opposite directions, generating a series voltage source. Since the movement directions of the induction coil 16 during the up-and-down strokes are opposite, the current direction of the generated series voltage source shows a periodic change, and this alternating current can be converted into direct current through a rectification and voltage stabilization circuit. The schematic diagram of the magnetic field direction of the annular Halbach magnet array and the schematic diagram of the structure of the annular Halbach magnet array and the induction coil are respectively as Figure 3 , Figure 4 shown.

[0035] The overall circuit of this measurement device includes: a main control circuit 21, a rectification, voltage stabilization / voltage division circuit 22, an energy storage circuit 23, a storage circuit 24, a signal conditioning circuit 25, a signal detection element 26, and an induction coil 16, specifically as Figure 5 shown, and the design of each part is as follows:

[0036] 1. The main control circuit uses an ADUC845 as the main control chip. Its advantage of low power consumption meets the working requirements in the special underground environment. The main control chip is responsible for the coordinated control and arithmetic processing of the entire circuit system.

[0037] 2. The rectification, voltage stabilization / voltage division circuit uses full-wave rectification to convert the alternating current generated by the induction coil into direct current and output voltages of 3.3V, 5V, and 12V to supply subsequent circuits and sensors.

[0038] 3. The energy storage circuit uses a supercapacitor bank composed of three supercapacitors connected in series for energy storage. A large resistor is connected in parallel to each supercapacitor bank to ensure the voltage balance across the supercapacitors and prevent damage to the capacitors.

[0039] 4. The storage circuit uses an N25Q128 flash memory chip to store the historical temperature and pressure data collected and the calculated flow rate data.

[0040] 5. The signal detection elements include proximity switches, temperature sensors, and pressure sensors. The collected temperature and pressure signals enter the AD acquisition channels of the single-chip microcomputer for AD conversion and are ultimately used for the calculation of gas flow rate.

Claims

1. A volumetric underground gas flow accurate measurement device capable of self-generating electricity, characterized by: The invention comprises a movable valve (1), a proximity switch (2), a cylinder (3), a reversing block (4), a piston rod (5), an inner sealing sleeve (6), an annular Halbach magnet array (7), a compression spring (8), an outer sleeve (9), a piston (10), a reversing rod (11), a pressure sensor (12), an upper reversing connecting rod (13), a lower reversing connecting rod (14), a coil-wound substrate (15), an induction coil (16), a temperature sensor (17), a middle exhaust hole (18), a left end air hole (19), and a right end air hole (20), and also comprises a hardware circuit system connected to the induction coil (16) and a signal detection element (26); The outer sleeve (9) is a cylindrical structure, and its thick end and thin end are respectively connected between two sections of oil pipes; The inner sealing sleeve (6) is installed in the outer sleeve (9), and the inlet and outlet of the piston rod (5) at both ends are sealed by sealing rings to form a closed space for placing the annular Halbach magnet array (7), the induction coil (16) and the compression spring (8); The movable valve (1) is a cylindrical structure with a hollow lower half, the middle exhaust hole (18) connects the lower space of the movable valve (1) with the outside, the left end air hole (19) is directly connected to the rodless cavity of the cylinder (3), and the right end air hole (20) is connected to the rod cavity of the cylinder (3) through an external pipeline; The cylinder (3) is a cylindrical structure, used for temporarily storing gas and guiding the piston (10) to perform linear reciprocating motion in the cylinder (3); The axial cross-section of the piston (10) is an H-shaped structure, which can increase the contact area between the piston (10) and the inner wall of the cylinder (3), thereby reducing gas leakage and preventing the piston (10) from deflecting or getting stuck during movement; in addition, the hollow design of the upper and lower parts can also minimize the deadweight of the piston (10) while ensuring a sufficient contact area; The piston rod (5) is a cylindrical structure, the top end of which is connected to the piston (10), a commutation block (4) is installed in the middle part, and a plurality of rectangular coil winding bases (15) are installed in the lower part, and an induction coil (16) is wound on the coil winding base (15); The compression spring (8) is sleeved on the end of the piston rod (5) to balance the total gravity of the piston rod (5) and all components mounted on the piston rod (5) and to reduce the inertial force generated by the reciprocating motion; The proximity switches (2) and pressure sensors (12) are two in number and are mounted on the top and bottom of the cylinder (3) respectively. The temperature sensor (17) is mounted on the inner wall of the outer sleeve (9).

2. A volumetric underground gas flow accurate measuring device capable of self-generating electricity according to claim 1, characterized in that: Two coil winding bases (15) are installed at the same height of the lower half of the piston rod (5), distributed in the left and right directions of the piston rod (5). Five groups of ten coil winding bases (15) can be installed at the lower end of the entire piston rod (5). The center distances of two adjacent groups of coil winding bases (15) are equal. A plurality of induction coils (16) are equally wound on each coil winding base (15), and the center distance between the upper and lower sides of the induction coil (16) is equal to half of the center distance between two adjacent groups of coil winding bases (15).

3. The self-generating volumetric underground gas flow accurate measuring device according to claim 1 is characterized in that: The annular Halbach magnet array (7) is embedded in the inner wall of the inner sealing sleeve (6), and its height is equal to the mid-distance between the upper and lower sides of the induction coil (16). The same group of annular Halbach magnet arrays (7) is at the same height and is composed of 12 magnets with different magnetization directions. 18 groups of annular Halbach magnet arrays (7) are arranged in sequence without gaps in the entire inner sealing sleeve (6). The internal magnetic fields generated by two adjacent groups of annular Halbach magnet arrays (7) are equal in size, parallel in opposite directions and perpendicular to the upper and lower sides of the induction coil (16).

4. A volumetric underground gas flow accurate measuring device capable of self-generating electricity according to claim 1, characterized in that: The volumes of the rod chamber and the rodless chamber of the cylinder (3) are fixed values, that is, the volume of gas discharged under the working condition of each stroke of the piston is fixed; based on the temperature and pressure data measured by the pressure sensor (12) and the temperature sensor (17) for each stroke, the single-chip microcomputer can perform temperature and pressure compensation on the fixed volume of gas discharged under the working condition of each stroke cylinder (3), and convert it into the volume of gas under standard conditions. The volume of gas under standard conditions calculated for each stroke is accumulated to obtain the total volume of gas injected within a period of time. The single-chip microcomputer calculates the ratio of the total volume to time once every period of time, and the average gas flow value within this period of time can be calculated.

5. The self-generating volumetric underground gas flow accurate measuring device according to claim 1 is characterized in that: The hardware circuit system comprises a main control circuit (21), a rectifying and stabilizing / voltage dividing circuit (22), an energy storage circuit (23), a storage circuit (24), and a signal conditioning circuit (25); the rectifying and stabilizing / voltage dividing circuit (22) is connected to the induction coil (16) to convert the alternating current generated by the induction coil (16) into direct current, a part of which is supplied to the energy storage circuit (23) for energy storage, and the other part is supplied to subsequent circuits; the signal detection element (26) is connected to the signal conditioning circuit (25) and the main control circuit (21) to process the measured temperature and pressure signals and transmit them to the single chip microcomputer for flow calculation.

Images