A tracer downhole layout and intelligent release system

Abstract

The present invention discloses a downhole layout and intelligent release system for tracers. The system includes a valve barrel, a tracer base pipe, and a lower connecting sleeve; the two ends of the valve barrel are respectively connected to an upper joint and the tracer base pipe, and a lower connecting sleeve is sleeved outside the tracer base pipe to form a tracer storage annulus; a central hole along its axial direction is provided in the middle of the valve barrel as a central passage, and an eccentric liquid injection passage and a plurality of eccentric flow-through ports are provided along the periphery of the central passage; a water nozzle is provided on the inner wall of the eccentric liquid injection passage, and the water nozzle is communicated with the central passage; the eccentric liquid injection passage is communicated with the tracer storage annulus; tracer outflow holes are provided on the outer wall of the lower connecting sleeve; a sliding ring is fitted at the lower end of the tracer storage annulus, and under the action of an external force, the sliding ring moves up and down to seal the tracer storage annulus or to communicate the tracer storage annulus with the tracer outflow holes. The system of the present invention can be used for tracer monitoring of oil and gas wells, monitoring of production of different outputs or different well sections, monitoring of reservoir production dynamics, evaluation of reservoir stimulation effects, etc.

Description

Technical Field

[0001] The present invention relates to a downhole layout and intelligent release system for tracers, belonging to the technical field of monitoring key production parameters during oil and gas exploitation. Background Art

[0002] The tracer inter-well monitoring technology can reflect the connectivity of oil and water wells during the water injection development process, monitor the advancing direction, displacement speed, swept area of the injected water, as well as reservoir heterogeneity and remaining oil saturation distribution, etc., which is particularly important for the study of remaining oil potential tapping in the later stage of oil and gas reservoir development. Currently, the injection of inter-well monitoring tracers is mainly carried out through the wellhead of the injection well.

[0003] Chinese invention patent CN 106761707 A discloses a tracer injection device, which adopts a closed type for adding tracers, solving the problem of radiation pollution caused by the exposed addition method. Chinese utility model patent CN205210713U discloses a remotely controlled oilfield tracer injection device, which uses various sensors and a PLC controller to ensure the stability of flow rate and concentration during the tracer injection process. At the same time, a wireless transmission system is used to achieve remote monitoring. However, at present, the inter-well monitoring of tracers has developed from a single tracer in a combined layer to multiple tracers in multiple layers. The above two tracer injection devices are mainly designed for the wellhead injection method and cannot meet the requirements of injecting multiple tracers in multiple layers, and there is a risk of cross-layer pollution. Chinese invention patent CN102392633 A discloses a new method and device for measuring tracers in injection wells for downhole use, mainly solving the problem that the traditional radioactive release method and device cannot form a slug by uniform mixing, effectively improving the quality of tracer flow logging in radioactive tracer logging technology, but cannot meet the requirements of injecting multiple tracers in multiple layers and the intelligent well intelligent management requirements. Chinese invention patent CN111141928A discloses a tracer delivery device and its use method, which is mainly applied to the field of water resources and groundwater science and engineering applications and cannot meet the requirements of oil and gas exploitation application fields.

[0004] To overcome the limitations of the traditional tracer injection method and meet the current intelligent well intelligent management requirements, it is urgent to develop a downhole layout and intelligent release system for tracers. Summary of the Invention

[0005] The object of the present invention is to provide a downhole layout and intelligent release system for tracers, which can not only meet the requirements of different release speeds required for different tracer monitoring purposes without fishing; at the same time, it can meet the requirements of injecting multiple tracers in multiple layers, avoiding the problem of cross-contamination during wellhead injection. On the other hand, by controlling the downhole tracer layout device through a cable, the release timing and release speed of the tracer can be reasonably selected according to the on-site requirements.

[0006] The tracer downhole layout and intelligent release system provided by the present invention includes a valve barrel, a tracer base pipe, and a lower connecting sleeve;

[0007] Both ends of the valve barrel are respectively connected to an upper joint and the tracer base pipe, and the lower connecting sleeve is sleeved outside the tracer base pipe to form a tracer storage annulus;

[0008] A central hole along its axis is provided in the middle of the valve barrel as a central channel, and an eccentric liquid injection channel and a plurality of eccentric flow ports are provided around the periphery of the central channel; a water nozzle is provided on the inner wall of the eccentric liquid injection channel, and the water nozzle is communicated with the central channel;

[0009] A programmable motor is provided in the eccentric liquid injection channel, and the opening or closing of the water nozzle is controlled by the programmable motor;

[0010] The eccentric liquid injection channel is communicated with the tracer storage annulus;

[0011] Tracer outflow holes are provided on the outer wall of the lower connecting sleeve;

[0012] A sliding ring is fitted at the lower end of the tracer storage annulus. Under the action of an external force, the sliding ring moves up and down to seal the tracer storage annulus or to communicate the tracer storage annulus with the tracer outflow holes.

[0013] In the above-mentioned tracer downhole layout and intelligent release system, the upper joint and the valve barrel are connected by threads;

[0014] The valve barrel and the tracer base pipe are connected by countersunk head screws, and a sealing washer is provided at the connection;

[0015] The tracer base pipe and the lower connecting sleeve are connected by threads, and a sealing washer is provided at the connection.

[0016] In the above-mentioned tracer downhole layout and intelligent release system, the diameter of the eccentric liquid injection channel is 15 mm to 20 mm;

[0017] Preferably, four of the eccentric flow ports are provided;

[0018] The programmable motor is connected to a lead screw nut, the other end of the lead screw nut is connected to a water nozzle plunger, and a pressure sensor is provided at the lower part of the water nozzle plunger. The opening degree of the water nozzle is determined by the pressure sensor to realize the adjustment of the tracer release speed.

[0019] In the above-mentioned tracer downhole layout and intelligent release system, the eccentric liquid injection channel and the tracer storage annulus are communicated through a connecting pipe so that the tracer flows into the tracer storage annulus.

[0020] In the above-described downhole layout and intelligent release system for tracers, a boss is provided inside the tracer storage annulus to limit the upward movement of the slip ring.

[0021] In the above-described downhole layout and intelligent release system for tracers, the lower end of the slip ring is connected to a spring, the spring is fixed on a spring base, and the spring base is provided on the lower connecting sleeve or the tracer base pipe, and an external force is applied to the slip ring through the spring; that is, under the action of the spring elastic force, the spring presses the slip ring tightly to prevent the tracer from overflowing.

[0022] When the slip ring is lower than the tracer outflow hole, the tracer flows out, and the value of the pressure sensor is set according to the corresponding downhole conditions, and the size of the water nozzle is controlled to enable the intelligent release of the tracer.

[0023] In the above-described downhole layout and intelligent release system for tracers, the spring base is installed on the lower connecting sleeve or the tracer base pipe by threads, and a pre-tightening force is applied through the spring seat threads to adjust the pressure magnitude.

[0024] The downhole layout and intelligent release system for tracers of the present invention can be used for tracer monitoring of oil and gas wells, monitoring of production in different production intervals or different well sections, monitoring of reservoir production dynamics, evaluation of reservoir stimulation effects, etc.

[0025] When using the downhole layout and intelligent release system for tracers of the present invention, the tracer is installed in the tracer storage annulus, the tracer is intelligently released as needed, and the reservoir and reservoir stimulation conditions of the monitoring well are determined by detecting the tracer content.

[0026] Through the tracer monitoring technology of the present invention, the tracer is intelligently released according to different downhole requirements of the monitoring well, and a better reservoir model can be established. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 It is a schematic structural diagram of the downhole layout and intelligent release system for tracers of the present invention.

[0028] Figure 2 It is an installation schematic diagram of the tracer release device for a certain well.

[0029] Figure 3 It is a schematic cross-sectional view of the valve barrel.

[0030] The marks in the figure are as follows:

[0031] 1. Upper joint; 2. Sealing ring; 3. Valve barrel; 4. Countersunk screw; 5. Tracer base pipe; 6. Sealing ring; 7. Lower connecting sleeve; 8. Slip ring; 9. Spring; 10. Spring base; 11. Sealing ring; 12. Bottom cover; 13. Eccentric barrel top cover; 14. Program-controlled motor; 15. Cable; 16. Cable passing hole; 17. 307. Nozzle; 18. Nozzle plunger; 19. Pressure sensor; 20. Connecting pipe; 21. Tracer storage annulus; 22. Tracer outflow hole; 301 Central hole; 302 Eccentric injection channel; 303. 304. 305. 306. Eccentric flow ports Detailed implementation method

[0032] Unless otherwise specified, the experimental methods used in the following examples are all conventional methods.

[0033] Unless otherwise specified, the materials, reagents, etc. used in the following examples can all be obtained from commercial channels.

[0034] As Figure 1 shown, it is a schematic structural diagram of the tracer downhole layout and intelligent release system provided by the present invention, and the structure is as follows:

[0035] The upper joint 1 is threadedly connected to the valve barrel 3, and a sealing ring 2 is provided at the connection. The valve barrel 3 is connected to the tracer base pipe 5 by countersunk screws 4. The tracer base pipe 5 is threadedly connected to the lower connecting sleeve 7, and a sealing ring 6 is provided at the connection. An annulus is formed between the tracer base pipe 5 and the lower connecting sleeve 7 as the tracer storage annulus.

[0036] As Figure 3 shown, a central hole 301 is provided in the middle of the valve barrel 3 as the central channel. An eccentric injection channel 302 and four eccentric flow ports 303 - 306 are evenly arranged along the periphery of the central channel. A nozzle 307 is provided on the inner wall of the eccentric injection channel 302. The nozzle 307 is communicated with the central channel of the valve barrel 3. The top of the eccentric injection channel 302 is installed with an eccentric barrel top cover 13 by threaded connection. A program-controlled motor 14 is arranged at the lower part of the eccentric barrel top cover 13. The program-controlled motor 14 is connected to a lead screw nut, and the other end of the lead screw nut is connected to a nozzle plunger 18. A pressure sensor 19 is provided at the lower part of the nozzle plunger 18. The opening degree of the nozzle 17 is determined by the pressure sensor 19 to realize the adjustment of the tracer release speed. Among them, the eccentric channel is communicated with the tracer storage annulus through a connecting pipe 20 so that the tracer flows into the tracer storage annulus. The electric cable 15 composed of the program-controlled motor and the sensor passes out of the valve barrel 3 from the cable passing hole 16, and the cable passing hole is filled with a leak-proof material. The port of the electric cable 15 is connected to the cable connecting the ground control system.

[0037] As Figure 1As shown in the figure, the lower end of the tracer storage annulus is fitted with a slip ring 8. The lower end of the slip ring 8 is connected to a spring 9, and the spring 9 is fixed on a spring base 10. The spring base 10 is arranged on the lower connecting sleeve 7. An external force is applied to the slip ring 8 through the spring 9, that is, under the action of the elastic force of the spring 9, the slip ring 8 moves up and down to seal the tracer storage annulus or to connect the tracer storage annulus with the tracer outflow hole 22. Preferably, the spring base 10 is installed on the lower connecting sleeve 7 by means of threads, and a pre-tightening force is applied through the spring seat threads to adjust the pressure magnitude. When the slip ring 8 is lower than the tracer outflow hole 22 provided on the outer wall of the lower connecting sleeve 7, the tracer flows out. The value of the pressure sensor 19 is set according to the corresponding downhole conditions to control the size of the water nozzle 17 so that the tracer is released intelligently.

[0038] When using the downhole layout and intelligent release system of the tracer of the present invention, the following steps can be carried out for installation:

[0039] 1. Drive the lead screw nut to rotate by controlling the program-controlled motor 14. The rotation of the nut causes the lead screw and the water nozzle plunger 18 to move up and down. The size of the opening of the water nozzle 17 is determined by the value set by the pressure sensor 19 installed at the lower part of the water nozzle plunger 18 to obtain the corresponding tracer release rate.

[0040] 2. During the water injection process, the injected liquid flows into the tracer storage annulus through the water nozzle 17. The slip ring 8 compresses the spring through the injection pressure, and the slip ring 8 moves. When the slip ring 8 moves below the tracer outflow hole 22, the tracer can flow out.

[0041] 3. Since the tracer release rates are different under different field conditions, the size of the water nozzle 17 is intelligently adjusted by adjusting the program-controlled motor 14 that controls the water nozzle 17 and setting the value of the pressure sensor 19 so that the tracer release rate is intelligently adjusted.

[0042] Specific operation steps are as follows:

[0043] 1. According to the depth of the production interval and the number of monitored intervals, the corresponding tracer release sub - joints are laid out in the corresponding injection intervals downhole and connected to the injection string.

[0044] 2. Lower the injection string of the oil and gas well with a series of tracer sub - joints downhole layout system into the well so that the tracer sub - joints downhole layout system is laid out in the corresponding injection intervals, as Figure 2 shown;

[0045] 3. During the injection process, control the size of the water nozzle through the program - controlled motor and the pressure sensor. The fluid flows into the tracer annulus through the water nozzle. The injection pressure causes the tracer to push the slider down until the side holes are opened to achieve intelligent release of the tracer.

[0046] 4. Take samples at the wellhead and analyze the downhole reservoir conditions by analyzing the tracer release concentration.

Claims

1. A tracer downhole layout and intelligent release system, comprising a valve barrel, a tracer base pipe and a lower connecting sleeve; The two ends of the valve barrel are respectively connected to an upper joint and the tracer base pipe, and the lower connecting sleeve is sleeved outside the tracer base pipe to form a tracer storage annulus; A central hole along its axis is provided in the middle of the valve barrel as a central channel, and an eccentric liquid injection channel and a plurality of eccentric flow ports are provided around the central channel; a nozzle is provided on the inner wall of the eccentric liquid injection channel, and the nozzle is communicated with the central channel; A programmed control motor is provided in the eccentric liquid injection channel, and the opening or closing of the nozzle is controlled by the programmed control motor; The eccentric liquid injection channel is communicated with the tracer storage annulus; Tracer outflow holes are provided on the outer wall of the lower connecting sleeve; The lower end of the tracer storage annulus is fitted with a slip ring, and under the action of an external force, the slip ring moves up and down to seal the tracer storage annulus or to communicate the tracer storage annulus with the tracer outflow holes; The diameter of the eccentric liquid injection channel is 15 - 20 mm; The programmed control motor is connected to a lead screw nut, the other end of the lead screw nut is connected to a nozzle plunger, and a pressure sensor is provided at the lower part of the nozzle plunger to determine the opening degree of the nozzle through the pressure sensor; The eccentric liquid injection channel and the tracer storage annulus are communicated through a connecting pipe; A boss is provided in the tracer storage annulus to limit the upward movement of the slip ring; The lower end of the slip ring is connected to a spring, the spring is fixed on a spring base, and the spring base is provided on the lower connecting sleeve or the tracer base pipe, and an external force is applied to the slip ring through the spring; 2. The tracer downhole layout and intelligent release system according to claim 1, wherein: The upper joint and the valve barrel are connected by threads; The valve barrel and the tracer base pipe are connected by countersunk head screws, and a sealing washer is provided at the connection; The tracer base pipe and the lower connecting sleeve are connected by threads, and a sealing washer is provided at the connection; 3. The tracer downhole layout and intelligent release system according to claim 1 or 2, characterized in that: The spring base is installed on the lower connecting sleeve or the tracer base pipe by threads, and a pre-tightening force is applied through the spring seat threads to adjust the pressure magnitude.

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