Liquid CO2 underground electric control throttling injection device and method

Abstract

According to the liquid CO2 underground electric control throttling injection device and method, in the device, one end of a main body is in threaded connection with an inner pipe, and the main body extends along the central axis of an upper protective sleeve; one end of the filter cartridge is in threaded connection with the other end of the main body; the valve water nozzle is connected with the other end of the valve push rod to adjust the injection opening; the wake-up switch assembly, the wireless communication antenna assembly and the radome are in threaded connection with the main body, and the wake-up switch assembly receives a wake-up instruction through the wireless communication antenna assembly and the radome; the pressure sensor is connected with the main body and forms sealing with the main body through an O-shaped sealing ring V, and the pressure sensor measures and generates pressure data; the wireless communication assembly is installed in the inner pipe to be wirelessly connected with the wake-up switch assembly, the pressure sensor, the gear motor and the control panel assembly, and the control panel assembly is installed in the inner pipe and controls the gear motor to drive the valve water nozzle to adjust the opening degree based on the wake-up instruction and / or the pressure data. The device realizes regulation and control of liquid CO2 oil displacement continuous liquid injection.

Description

Technical Field

[0001] The present invention relates to the technical field of oil drilling tools, and in particular to a downhole electric-controlled throttling injection device and method for liquid CO2. Background Art

[0002] Gas injection for oil recovery, especially liquid CO2 injection for enhanced oil recovery (CO2-EOR) projects, has increased year by year and has become one of the important means to increase crude oil production worldwide. Generally, every 2.5-4.1 tons of liquid CO2 injected into an oil field can increase oil production by 1 ton.

[0003] During the injection of liquid CO2, it is necessary to solve the problem of injection continuity during the utilization or storage process, solve the construction reliability, automation and intelligence of key injection equipment, and while improving the injection and production system of liquid CO2 oil recovery technology, continuous, timely and reasonable dynamic fluid adjustment is of special importance for controlling liquid and stabilizing oil in small blocks with high water content, close to wells, good physical properties and large differences between plane layers in oil fields. It is particularly important to carry out predictive fluid adjustment based on dynamic change laws and monitoring reflections.

[0004] The above information disclosed in this Background section is only for enhancement of understanding of the background of the invention and therefore it may contain information that does not form the prior art that is already known to a person of ordinary skill in the art. Summary of the invention

[0005] The purpose of the present invention is to provide a liquid CO2 downhole electrically controlled throttling injection device to complete the collection of relevant data such as downhole flow rate and pressure, and the adjustable water nozzle meets the requirements of liquid CO2 oil recovery technology target layer injection volume control, forming a tool suitable for the liquid CO2 step-by-step segmented injection process.

[0006] In order to achieve the above object, the present invention provides the following technical solutions:

[0007] A liquid CO2 downhole electric-controlled throttling injection device of the present invention comprises:

[0008] Upper joint;

[0009] An upper protective sleeve, which is threadedly connected to the upper joint;

[0010] An inner tube, which is disposed in the upper protective sleeve with clearance and is connected to the upper joint;

[0011] A main body, one end of which is threadedly connected to the inner tube, and the main body extends along the central axis of the upper protective sleeve;

[0012] A filter cartridge, one end of which is threadedly connected to the center hole of the other end of the main body;

[0013] A lower joint connected to the other end of the filter cartridge with clearance fit;

[0014] A lower protective sleeve, one end of which is threadedly connected to the lower joint, and the other end of which is threadedly connected to the main body;

[0015] A reduction motor is arranged between the inner tube and the upper protective sleeve;

[0016] A lead screw, one end of which is connected to the reduction motor via a thrust bearing shaft;

[0017] A valve push rod, one end of which is connected to the other end of the lead screw;

[0018] A valve faucet is connected to the other end of the valve push rod to adjust the injection opening.

[0019] A faucet sealing valve sleeve, which is threadedly connected to the main body, and the faucet sealing valve sleeve provides sealing for the valve faucet when it is closed through an O-ring III;

[0020] The wake-up switch assembly, the wireless communication antenna assembly and the radome are threadedly connected to the main body, and the wake-up switch assembly receives the wake-up instruction via the wireless communication antenna assembly and the radome;

[0021] A pressure sensor is connected to the main body and forms a seal with the main body through an O-ring V, and the pressure sensor measures and generates pressure data;

[0022] A wireless communication component is installed on the inner tube to wirelessly connect the wake-up switch component, the pressure sensor, the reduction motor and the control board component,

[0023] A control panel assembly is installed on the inner tube and controls the reduction motor to drive the valve faucet to adjust the opening based on the wake-up instruction and / or pressure data.

[0024] The liquid CO2 downhole electrically controlled throttling injection device also includes a flow rate sensor and / or a temperature sensor installed on the outer wall of the main body. The control panel assembly is connected to the flow rate sensor and / or the temperature sensor and controls the reduction motor to drive the valve nozzle to adjust the opening based on the flow rate data and / or temperature data.

[0025] The liquid CO2 downhole electrically controlled throttling injection device also includes a battery pack mounted on the inner tube, and the battery pack is electrically connected to the reduction motor, the wake-up switch assembly, the wireless communication antenna assembly, the pressure sensor, the wireless communication assembly and the control panel assembly.

[0026] In the liquid CO2 downhole electrically controlled throttling injection device, the upper protective sleeve and the upper joint are sealed via an O-ring I, the inner tube and the upper protective sleeve are sealed via an O-ring II, and the main body and the inner tube are sealed via an annular sealing gasket.

[0027] The liquid CO2 downhole electric-controlled throttling injection device further includes:

[0028] A coupling connected to the reduction motor and extending between the inner tube and the upper protective sleeve in a direction parallel to the central axis of the upper protective sleeve;

[0029] A thrust bearing seat is installed between the inner tube and the upper protective sleeve, and a thrust bearing is installed on the thrust bearing seat.

[0030] A thrust bearing shaft is inserted into the thrust bearing, one end of the thrust bearing shaft is connected to the coupling, and the other end is connected to the lead screw.

[0031] The dynamic seal ring is installed between the valve push rod and the valve guide sleeve to provide dynamic sealing.

[0032] Dynamic sealing gasket, which is set between the valve push rod and the body to provide dynamic sealing,

[0033] The valve guide sleeve is arranged between the valve push rod and the upper protective sleeve, and the valve push rod is movable relative to the valve guide sleeve.

[0034] In the liquid CO2 downhole electric-controlled throttling injection device, the reduction motor is embedded in the motor sleeve, and the motor sleeve, coupling, thrust bearing seat, thrust bearing, thrust bearing shaft, thrust bearing shaft connecting screw, lead screw, valve guide sleeve, valve push rod, dynamic sealing ring, dynamic sealing gasket and valve faucet are connected in sequence and fixed to the main body through top screws, hexagon socket screws, spring washers and first washers.

[0035] In the liquid CO2 downhole electrically controlled throttling injection device, the wake-up switch assembly, the wireless communication antenna assembly and the antenna cover are located between the lower protective cover and the main body.

[0036] In the liquid CO2 downhole electric-controlled throttling injection device, the oil film sealing piston, the pressure sensor valve sleeve, the pressure sealing pad and the pressure sensor are sequentially threadedly connected to the main body and are sealed with the main body through an O-ring V.

[0037] In the liquid CO2 downhole electric-controlled throttling injection device, the wireless communication component, the control panel mounting frame and the control panel assembly are installed on the inner tube by means of a slotted pan head screw II and a second washer, and the wireless communication component, the control panel mounting frame and the control panel assembly are located between the upper protective cover and the main body.

[0038] A method for injecting liquid CO2 downhole electrically controlled throttling injection device comprises the following steps:

[0039] The pressure sensor collects the pressure data of the current injection layer and generates a predetermined liquid flow rate of liquid CO2 based on the pressure data.

[0040] The measuring instrument with magnetic awakening function awakens the liquid CO2 underground electric control throttling injection device through the awakening switch component, and controls the reduction motor to drive the valve push rod to adjust the opening of the valve water nozzle according to the predetermined liquid flow value.

[0041] The actual liquid flow rate is compared with the predetermined liquid flow rate, and the reduction motor is controlled to rotate forward or reverse to change the size of the valve nozzle to adjust the flow rate until the error between the actual liquid flow rate and the predetermined liquid flow rate is less than a predetermined threshold.

[0042] In the above technical scheme, a liquid CO2 downhole electrically controlled throttling injection device and method provided by the present invention have the following beneficial effects: in the liquid CO2 downhole electrically controlled throttling injection device, the battery pack and the reduction motor are actuators, and the water nozzle can be adjusted in size; each section adopts a hollow structure, which can be entered and adjusted between any layers; the integrated communication short section realizes command input and data transmission; multiple devices are synchronized for measurement and adjustment, and the number of layers is not limited, which greatly improves the measurement and adjustment efficiency; integrated flow, pressure and temperature sensors are used to monitor downhole stratification parameters in real time, meet the requirements of liquid CO2 oil recovery stratification injection / stratification production, realize pressure / temperature / injection flow monitoring of each layer and remote control of layer flow, realize refined reservoir management (interlayer management), and maximize the final recovery rate. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in the present invention. For ordinary technicians in this field, other drawings can also be obtained based on these drawings.

[0044] Figure 1 A schematic structural diagram of a liquid CO2 downhole electrically controlled throttling injection device provided in an embodiment of the present invention.

[0045] Figure 2 A partial structural schematic diagram of a liquid CO2 downhole electrically controlled throttling injection device provided in an embodiment of the present invention. DETAILED DESCRIPTION

[0046] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0047] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the invention claimed for protection, but merely represents selected embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0048] It should be noted that similar reference numerals and letters denote similar items in the following drawings, and therefore, once an item is defined in one drawing, further definition and explanation thereof is not required in subsequent drawings.

[0049] 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", "clockwise", "counterclockwise" and the like 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, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present invention.

[0050] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.

[0051] In the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be directly connected or indirectly connected through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0052] In the present invention, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may include that the first and second features are in direct contact, or may include that the first and second features are not in direct contact but are in contact through another feature between them. Moreover, a first feature being "above", "above" and "above" a second feature includes that the first feature is directly above and obliquely above the second feature, or simply indicates that the first feature is higher in level than the second feature. A first feature being "below", "below" and "below" a second feature includes that the first feature is directly below and obliquely below the second feature, or simply indicates that the first feature is lower in level than the second feature.

[0053] In order to enable those skilled in the art to better understand the technical solution of the present invention, the present invention will be further described in detail below with reference to the accompanying drawings.

[0054] See also Figure 1-2 As shown, in one embodiment, a liquid CO2 downhole electric-controlled throttling injection device of the present invention comprises:

[0055] Upper connector 1;

[0056] An upper protective sleeve 5, which is threadedly connected to the upper joint 1;

[0057] An inner tube 4, which is disposed in the upper protective sleeve 5 with clearance and is connected to the upper joint 1;

[0058] A main body 21, one end of which is threadedly connected to the inner tube 4, and the main body 21 extends along the central axis of the upper protective sleeve 5;

[0059] A filter cartridge 24, one end of which is threadedly connected to the center hole of the other end of the main body 21;

[0060] A lower joint 25, which is connected to the other end of the filter cartridge 24 with clearance fit;

[0061] A lower protective sleeve 23, one end of which is threadedly connected to the lower joint 25, and the other end of which is threadedly connected to the main body 21;

[0062] A reduction motor 6, which is arranged between the inner tube 4 and the upper protective sleeve 5;

[0063] A lead screw 13, one end of which is connected to the reduction motor 6 via a thrust bearing shaft 11;

[0064] A valve push rod 15, one end of which is connected to the other end of the lead screw 13;

[0065] The valve nozzle 19 is connected to the other end of the valve push rod 15 to adjust the injection opening.

[0066] The faucet sealing valve sleeve 22 is threadedly connected to the main body 21, and the faucet sealing valve sleeve 22 provides sealing for the valve faucet 19 when it is closed through the O-ring III 20;

[0067] The wake-up switch assembly 26, the wireless communication antenna assembly 27 and the antenna cover 28 are threadedly connected to the main body 21, and the wake-up switch assembly 26 receives the wake-up instruction via the wireless communication antenna assembly 27 and the antenna cover 28;

[0068] A pressure sensor 34, which is connected to the main body 21 and forms a seal with the main body 21 through an O-ring V31, and the pressure sensor 34 measures and generates pressure data;

[0069] A wireless communication component 40 is installed on the inner tube 4 to wirelessly connect the wake-up switch component 26, the pressure sensor 34, the reduction motor 6 and the control board component 42,

[0070] The control panel assembly 42 is installed on the inner tube 4 and controls the reduction motor 6 to drive the valve faucet 19 to adjust the opening based on the wake-up instruction and / or pressure data.

[0071] In a preferred embodiment of the liquid CO2 downhole electrically controlled throttling injection device, it also includes a flow rate sensor and / or a temperature sensor installed on the outer wall of the main body 21, and the control board assembly 42 is connected to the flow rate sensor and / or the temperature sensor and controls the reduction motor 6 to drive the valve nozzle 19 to adjust the opening based on the flow rate data and / or temperature data.

[0072] In a preferred embodiment of the liquid CO2 downhole electrically controlled throttling injection device, it also includes a battery pack 39 mounted on the inner tube 4, and the battery pack 39 is electrically connected to the reduction motor 6, the wake-up switch assembly 26, the wireless communication antenna assembly 27, the pressure sensor 34, the wireless communication assembly 40 and the control panel assembly 42.

[0073] In a preferred embodiment of the liquid CO2 downhole electrically controlled throttling injection device, the upper protective sleeve 5 and the upper joint 1 are sealed via an O-ring Ⅰ2, the inner tube 4 and the upper protective sleeve 5 are sealed via an O-ring Ⅱ3, and the main body 21 and the inner tube 4 are sealed via an annular sealing gasket 18.

[0074] In a preferred embodiment of the liquid CO2 downhole electric-controlled throttling injection device, the device further comprises:

[0075] A coupling 8 connected to the reduction motor 6 and extending between the inner tube 4 and the upper protective sleeve 5 in a direction parallel to the central axis of the upper protective sleeve 5;

[0076] A thrust bearing seat 9 is installed between the inner tube 4 and the upper protective sleeve 5, and a thrust bearing 10 is installed on the thrust bearing seat 9.

[0077] The thrust bearing shaft 11 is inserted into the thrust bearing 10, one end of the thrust bearing shaft 11 is connected to the coupling 8, and the other end is connected to the lead screw 13.

[0078] The dynamic seal ring 16 is sleeved between the valve push rod 15 and the valve guide sleeve 14 to provide dynamic sealing.

[0079] The dynamic sealing gasket 17 is sleeved between the valve push rod 15 and the main body 21 to provide dynamic sealing.

[0080] The valve guide sleeve 14 is disposed between the valve push rod 15 and the upper protective sleeve 5 , and the valve push rod 15 is movable relative to the valve guide sleeve 14 .

[0081] In a preferred embodiment of the liquid CO2 downhole electric-controlled throttling injection device, the reduction motor 6 is embedded in the motor sleeve 7, and the motor sleeve 7, coupling 8, thrust bearing seat 9, thrust bearing 10, thrust bearing shaft 11, thrust bearing shaft connecting screw 12, screw 13, valve guide sleeve 14, valve push rod 15, dynamic sealing ring 16, dynamic sealing gasket 17 and valve faucet 19 are connected in sequence and fixed to the main body 21 through top screw 35, hexagon socket screw 36, spring washer 37 and first washer 38.

[0082] In a preferred embodiment of the liquid CO2 downhole electrically controlled throttling injection device, the wake-up switch assembly 26 , the wireless communication antenna assembly 27 and the antenna cover 28 are located between the lower protective cover 23 and the main body 21 .

[0083] In a preferred embodiment of the liquid CO2 downhole electrically controlled throttling injection device, the oil film sealing piston 30, the pressure sensor valve sleeve 32, the pressure sealing pad 33 and the pressure sensor 34 are sequentially threadedly connected to the main body 21 and are sealed with the main body 21 through an O-ring V31.

[0084] In a preferred embodiment of the liquid CO2 downhole electrically controlled throttling injection device, the wireless communication component 40, the control panel mounting frame 41 and the control panel assembly 42 are installed on the inner tube 4 by means of a slotted pan head screw Ⅱ 43 and a second washer 44, and the wireless communication component 40, the control panel mounting frame 41 and the control panel assembly 42 are located between the upper protective cover 5 and the main body 21.

[0085] In one embodiment, a liquid CO2 downhole electric-controlled throttling injection device comprises:

[0086] An upper connector 1, which is provided with an external thread;

[0087] An upper protective sleeve 5 is provided with an internal thread for threaded connection with the upper joint 1, and the upper protective sleeve 5 and the upper joint 1 are sealed via an O-ring Ⅰ2;

[0088] An inner tube 4 is provided in the upper protective sleeve 5 with clearance and is connected to the upper joint 1. The inner tube 4 and the upper protective sleeve 5 are sealed via an O-ring II 3.

[0089] A main body 21, one end of which is threadedly connected to the inner tube 4, the main body 21 extends along the central axis of the upper protective sleeve 5, and the main body 21 and the inner tube 4 are sealed via an annular sealing gasket 18;

[0090] A filter cartridge 24, one end of which is threadedly connected to the center hole of the other end of the main body 21;

[0091] A lower joint 25, which is connected to the other end of the filter cartridge 24 with clearance fit;

[0092] A lower protective sleeve 23, one end of which is threadedly connected to the lower joint 25, and the other end of which is threadedly connected to the main body 21;

[0093] A reduction motor 6 is arranged between the inner tube 4 and the upper protective cover 5, and the reduction motor 6 is embedded in the motor cover 7;

[0094] A coupling 8 connected to the reduction motor 6 and extending between the inner tube 4 and the upper protective sleeve 5 in a direction parallel to the central axis of the upper protective sleeve 5;

[0095] A thrust bearing seat 9 is installed between the inner tube 4 and the upper protective sleeve 5, and a thrust bearing 10 is installed on the thrust bearing seat 9.

[0096] The thrust bearing shaft 11 is passed through the thrust bearing 10, and one end of the thrust bearing shaft 11 is connected to the coupling 8.

[0097] A lead screw 13, one end of which is connected to the other end of the thrust bearing shaft 11 via a thrust bearing shaft connecting screw 12,

[0098] A valve push rod 15, one end of which is connected to the other end of the lead screw 13;

[0099] The valve guide sleeve 14 is disposed between the valve push rod 15 and the upper protective sleeve 5, and the valve push rod 15 is movable relative to the valve guide sleeve 14.

[0100] The dynamic seal ring 16 is sleeved between the valve push rod 15 and the valve guide sleeve 14 to provide dynamic sealing.

[0101] The dynamic sealing gasket 17 is sleeved between the valve push rod 15 and the main body 21 to provide dynamic sealing.

[0102] The valve faucet 19 is connected to the other end of the valve push rod 15 to adjust the injection opening, and the motor sleeve 7, the coupling 8, the thrust bearing seat 9, the thrust bearing 10, the thrust bearing shaft 11, the thrust bearing shaft connecting screw 12, the lead screw 13, the valve guide sleeve 14, the valve push rod 15, the dynamic sealing ring 16, the dynamic sealing gasket 17 and the valve faucet 19 are sequentially connected and fixed to the main body 21 through the top screw 35, the hexagon socket screw 36, the spring washer 37 and the first gasket 38;

[0103] The faucet sealing valve sleeve 22 is threadedly connected to the main body 21, and the faucet sealing valve sleeve 22 provides sealing for the valve faucet 19 when it is closed through the O-ring III 20;

[0104] The wake-up switch assembly 26, the wireless communication antenna assembly 27 and the antenna cover 28 are sequentially threadedly connected to the main body 21 and form a seal with the main body 21 through an O-ring IV 29. The wake-up switch assembly 26, the wireless communication antenna assembly 27 and the antenna cover 28 are located between the lower protective cover 23 and the main body 21.

[0105] The oil film sealing piston 30, the pressure sensor valve sleeve 32, the pressure sealing pad 33 and the pressure sensor 34 are connected to the main body 21 by threads in sequence and form a seal with the main body 21 through an O-ring V31. The oil film sealing piston 30, the pressure sensor valve sleeve 32, the pressure sealing pad 33 and the pressure sensor 34 are located between the upper protective sleeve 5 and the main body 21.

[0106] A battery pack 39, which is placed on the inner tube 4;

[0107] The wireless communication component 40 , the control panel mounting frame 41 and the control panel component 42 are installed on the inner tube 4 by means of slotted pan head screws II 43 and a second washer 44 . The wireless communication component 40 , the control panel mounting frame 41 and the control panel component 42 are located between the upper protective cover 5 and the main body 21 .

[0108] A method for injecting liquid CO2 downhole electrically controlled throttling injection device comprises the following steps:

[0109] The pressure sensor 34 collects the pressure data of the current injection layer and generates a predetermined liquid flow rate of liquid CO2 according to the pressure data.

[0110] The measuring instrument with magnetic awakening function awakens the liquid CO2 downhole electric control throttling injection device through the awakening switch component 26, and controls the reduction motor 6 to drive the valve push rod 15 to adjust the opening of the valve nozzle 19 according to the predetermined liquid flow value.

[0111] The actual liquid flow rate is compared with the predetermined liquid flow rate, and the reduction motor 6 is controlled to rotate forward or reverse to change the size of the valve nozzle 19 to adjust the flow rate until the error between the actual liquid flow rate and the predetermined liquid flow rate is less than a predetermined threshold.

[0112] In one embodiment, when the liquid CO2 downhole electric-controlled throttling injection device is tested on site, a measuring instrument with a magnetic awakening function is lowered to the predetermined downhole electric-controlled throttling injection device by cable delivery, and the liquid CO2 downhole electric-controlled throttling injection device is activated. Then, the flow adjustment expected value is set according to the liquid distribution plan, and then the flow measurement and control processor and the regulating controller are connected together for downhole adjustment. The actual liquid distribution amount is tested by the measurement and control processor and compared with the desired liquid distribution amount, and the reduction motor 6 is controlled to rotate forward or reverse according to the comparison result. The rotational motion of the motor is transmitted to the spiral transmission mechanism such as the screw 13 in the adjustable device through a universal coupling or a coupling 8, so that the valve core produces axial movement, the size of the water outlet is changed, and the purpose of adjusting the flow is achieved. When the flow meets the expected value requirement, the adjustment stops automatically. As needed, the well can be lowered once and multiple layers can be distributed.

[0113] In one embodiment, the liquid CO2 downhole electric control throttling injection device is not limited by the layer segment in oil displacement stratification. The ground directly reads the flow rate of the downhole small layer, and the downhole flow rate is continuously adjusted steplessly through the flow regulation system. The equipment consists of ground test equipment, downhole test system, downhole electric control throttling injection device and other parts.

[0114] In one embodiment, a liquid CO2 downhole electric control throttling injection device first collects data information of the current injection layer through a pressure sensor 34, then undergoes A / D conversion, and stores the converted digital information. The data is transmitted to the control host through a cable, and a cable packer is used between each injection layer to remove interference. At the same time, the reduction motor 6 is driven according to the pre-set liquid flow value, thereby adjusting the opening value of the valve nozzle 19 to complete the automatic allocation of the liquid flow of the layer section. The hardware circuits of all acquisition and control components are located in the liquid CO2 downhole electric control throttling injection device. The downhole measuring device and the data transmission cable perform two functions: using the sensor installed in the measuring instrument to measure the pressure, temperature, flow rate and other data of each injection interval, and collecting the data through the cable, and finally transmitting it to the ground control system; according to the feedback signal from the ground control system, the valve nozzle 19 of the device is adjusted by the drive system motor and the measuring instrument. The liquid CO2 step-by-step injection tool can be injected in 10 stages, with a low temperature resistance of -20°C and a pressure of 30MPa. The measuring instrument is connected to the downhole electric-controlled throttling injection device, and the injection parameters are fed back to the ground controller in real time. According to the instructions issued from the ground, the water nozzle opening of the device is adjusted to meet the geological injection requirements, so that the multi-layer flow test and deployment tasks can be completed in one trip to the well.

[0115] In one embodiment, in a liquid CO2 downhole electric-controlled throttling injection device, the upper joint 1, the upper protective sleeve 5, the main body 21, the lower protective sleeve 23 and the lower joint 25 are all connected by metric threads, sealed by an O-ring Ⅰ2, and have sealing, tensile (compression) and torque transmission functions at the same time; the inner tube 4 and the main body 21 are connected by metric threads and sealed by an annular sealing gasket 18; the inner tube 4 and the upper protective sleeve 5 are clearance-matched and sealed by an O-ring Ⅱ3; the 24V high-temperature-resistant reduction motor 6 is embedded in the motor sleeve 7 and is sealed by the top The motor sleeve 7, coupling 8, thrust bearing seat 9, thrust bearing 10, thrust bearing shaft 11, thrust bearing shaft connecting screw 12, lead screw 13, valve guide sleeve 14, valve push rod 15, dynamic sealing ring 16, dynamic sealing gasket 17 and valve faucet 19 are connected in sequence and fixed to the left upper end of the main body 21 through top screw 35, hexagon socket screw 36, spring washer 37 and first gasket 38; the dynamic sealing ring 16 and the dynamic sealing gasket 17 provide dynamic sealing for the valve push rod 15 and the main body 21.

[0116] In one embodiment, the faucet sealing valve sleeve 22 is connected to the upper right end of the main body 21 through metric threads, and the valve faucet 19 is sealed when closed through the O-ring III 20. The filter cartridge 24 is connected to the right center hole of the main body 21 through metric threads, and the lower end is clearance-matched with the lower joint 25, and its main function is to prevent large objects from blocking the throttling channel; the wake-up switch assembly 26, the wireless communication antenna assembly 27, and the antenna cover 28 are connected to the lower right end of the main body 21 in sequence through metric threads, and are sealed with the main body 21 through the O-ring IV 29; the oil film sealing piston 30, the pressure sensor valve sleeve 32, the pressure sealing pad 33 and the pressure sensor 34 are connected to the left front of the main body 21 in sequence through metric threads, and are sealed with the main body 21 through the O-ring V 31; the 28V battery pack 39 is placed behind the left side of the inner tube 4; the wireless communication assembly 40, the control panel mounting frame 41 and the control panel assembly 42 are installed in the left front of the inner tube 4 through the slotted pan head screw II 43 and the second gasket 44.

[0117] Finally, it should be noted that the described embodiments are only part of the embodiments of the present application, rather than all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without making any creative work are within the scope of protection of the present application.

[0118] The above description is only by way of illustration of certain exemplary embodiments of the present invention. It is undoubted that those skilled in the art can modify the described embodiments in various ways without departing from the spirit and scope of the present invention. Therefore, the above drawings and descriptions are illustrative in nature and should not be construed as limiting the scope of protection of the claims of the present invention.

Claims

1. A liquid CO2 downhole electric-controlled throttling injection device, characterized in that: These include, Upper joint; An upper protective sleeve, which is threadedly connected to the upper joint; An inner tube, which is disposed in the upper protective sleeve with clearance and is connected to the upper joint; A main body, one end of which is threadedly connected to the inner tube, and the main body extends along the central axis of the upper protective sleeve; A filter cartridge, one end of which is threadedly connected to the center hole of the other end of the main body; A lower joint connected to the other end of the filter cartridge with clearance fit; A lower protective sleeve, one end of which is threadedly connected to the lower joint, and the other end of which is threadedly connected to the main body; A reduction motor is arranged between the inner tube and the upper protective sleeve; A lead screw, one end of which is connected to the reduction motor via a thrust bearing shaft; A valve push rod, one end of which is connected to the other end of the lead screw; A valve faucet is connected to the other end of the valve push rod to adjust the injection opening. A faucet sealing valve sleeve, which is threadedly connected to the main body, and the faucet sealing valve sleeve provides sealing for the valve faucet when it is closed through an O-ring III; The wake-up switch assembly, the wireless communication antenna assembly and the radome are threadedly connected to the main body, and the wake-up switch assembly receives the wake-up instruction via the wireless communication antenna assembly and the radome; A pressure sensor is connected to the main body and forms a seal with the main body through an O-ring V, and the pressure sensor measures and generates pressure data; A wireless communication component is installed on the inner tube to wirelessly connect the wake-up switch component, the pressure sensor, the reduction motor and the control board component, A control panel assembly is installed on the inner tube and controls the reduction motor to drive the valve faucet to adjust the opening based on the wake-up instruction and / or pressure data.

2. A liquid CO2 downhole electric-controlled throttling injection device according to claim 1, characterized in that: It also includes a flow rate sensor and / or a temperature sensor installed on the outer wall of the main body. The control board assembly is connected to the flow rate sensor and / or the temperature sensor and controls the reduction motor to drive the valve faucet to adjust the opening based on the flow rate data and / or the temperature data.

3. A liquid CO2 downhole electric-controlled throttling injection device according to claim 1, characterized in that: It also includes a battery pack mounted on the inner tube, and the battery pack is electrically connected to the reduction motor, the wake-up switch assembly, the wireless communication antenna assembly, the pressure sensor, the wireless communication assembly and the control board assembly.

4. A liquid CO2 downhole electric-controlled throttling injection device according to claim 1, characterized in that: The upper protective sleeve and the upper joint are sealed via an O-ring I, the inner tube and the upper protective sleeve are sealed via an O-ring II, and the main body and the inner tube are sealed via an annular sealing gasket.

5. A liquid CO2 downhole electric-controlled throttling injection device according to claim 1, characterized in that: Also includes, A coupling connected to the reduction motor and extending between the inner tube and the upper protective sleeve in a direction parallel to the central axis of the upper protective sleeve; A thrust bearing seat is installed between the inner tube and the upper protective sleeve, and a thrust bearing is installed on the thrust bearing seat. A thrust bearing shaft is inserted into the thrust bearing, one end of the thrust bearing shaft is connected to the coupling, and the other end is connected to the lead screw. The dynamic seal ring is installed between the valve push rod and the valve guide sleeve to provide dynamic sealing. Dynamic sealing gasket, which is set between the valve push rod and the body to provide dynamic sealing, The valve guide sleeve is arranged between the valve push rod and the upper protective sleeve, and the valve push rod is movable relative to the valve guide sleeve.

6. A liquid CO2 downhole electric-controlled throttling injection device according to claim 5, characterized in that: The reduction motor is embedded in the motor sleeve, and the motor sleeve, coupling, thrust bearing seat, thrust bearing, thrust bearing shaft, thrust bearing shaft connecting screw, lead screw, valve guide sleeve, valve push rod, dynamic sealing ring, dynamic sealing gasket and valve faucet are connected in sequence and fixed to the main body through top screws, hexagon socket screws, spring washers and first washers.

7. A liquid CO2 downhole electric-controlled throttling injection device according to claim 1, characterized in that: The wake-up switch assembly, the wireless communication antenna assembly and the antenna cover are located between the lower protective cover and the main body.

8. A liquid CO2 downhole electric-controlled throttling injection device according to claim 1, characterized in that: The oil film sealing piston, the pressure sensor valve sleeve, the pressure sealing pad and the pressure sensor are connected to the main body through threads in sequence and form a seal with the main body through an O-ring V.

9. A liquid CO2 downhole electric-controlled throttling injection device according to claim 1, characterized in that: The wireless communication component, the control panel mounting frame and the control panel assembly are installed on the inner tube through the slotted pan head screw II and the second washer. The wireless communication component, the control panel mounting frame and the control panel assembly are located between the upper protective cover and the main body.

10. A method for injecting liquid CO2 downhole electrically controlled throttling injection device according to any one of claims 1 to 9, characterized in that: It includes The following steps, The pressure sensor collects the pressure data of the current injection layer and generates a predetermined liquid flow rate of liquid CO2 based on the pressure data. The measuring instrument with magnetic awakening function awakens the liquid CO2 underground electric control throttling injection device through the awakening switch component, and controls the reduction motor to drive the valve push rod to adjust the opening of the valve water nozzle according to the predetermined liquid flow value. The actual liquid flow rate is compared with the predetermined liquid flow rate, and the reduction motor is controlled to rotate forward or reverse to change the size of the valve nozzle to adjust the flow rate until the error between the actual liquid flow rate and the predetermined liquid flow rate is less than a predetermined threshold.

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