Steam injection well with monitoring function

Abstract

The invention discloses a steam injection well with a monitoring function, which is characterized in that a well pipe is arranged in the well, the well pipe sequentially comprises a solid pipe, a screen pipe and a precipitation pipe from top to bottom, and a plug is arranged at the lower end of the precipitation pipe; the outer side of the screen pipe is coated with a screen mesh, and the screen pipe and the precipitation pipe are coated with quartz sand; the upper end of the solid pipe is sealed, a temperature sensor used for monitoring the temperature in the well, a liquid level sensor used for monitoring the liquid level in the well and a pressure sensor used for monitoring the steam pressure in the well are installed on the solid pipe, the space between the solid pipe and soil is filled with a sealing soil layer preventing steam leakage, and a steam injection pipe is further arranged on the upper portion of the solid pipe. Temperature, pressure and water level monitoring is added in the steam injection well, the underground high-temperature and high-pressure environment can be monitored in real time, it is ensured that the steam temperature meets the technical requirement, damage to a well structure or a stratum due to overpressure is avoided, it is ensured that steam can be smoothly injected to the target depth of a polluted area, and the pollution rate is increased. Therefore, the soil remediation effect and safety are improved.

Description

Technical Field

[0001] The present invention relates to the technical field of environmental remediation, and in particular to a steam injection well with a monitoring function, which is suitable for a gas injection well structure of an in-situ steam thermal desorption technology in a soil remediation project. Background Art

[0002] Steam injection wells are widely used in in-situ steam thermal desorption technology in soil remediation projects. In-situ steam thermal desorption technology injects high-temperature steam into underground contaminated areas to volatilize, parse or decompose pollutants in the soil, and then captures and treats these pollutants through an extraction system. In-situ steam thermal desorption technology is particularly suitable for treating sites contaminated by volatile or semi-volatile organic compounds, and is often used in areas with deep contaminated soil and groundwater.

[0003] As a key component of this technology, steam injection wells are responsible for transporting steam to the target depth of the underground contaminated area. Through the steam injection wells, the steam heats the surrounding soil and groundwater by heat conduction and convection. However, traditional steam injection wells usually lack real-time monitoring and evaluation of the operating status in the well, which limits the control of key parameters in the steam injection process, such as whether the injection temperature of the steam meets the technical requirements, whether the steam phase remains stable, and whether the water level in the well is below the screen to ensure that the steam can be effectively discharged through the screen holes. Since these key parameters cannot be accurately controlled, the remediation effect may not be guaranteed, a lot of energy may be wasted, and even excessive pressure may cause adverse geological consequences such as formation rupture. Summary of the invention

[0004] In order to solve the technical problems existing in traditional steam injection wells, the present invention provides a steam injection well with a monitoring function. By optimizing the design of the steam injection well, real-time monitoring of the underground environment is added. Through these monitoring systems, the steam injection parameters can be adjusted in real time to ensure that the steam injection system operates under efficient and stable conditions, effectively improve the quality of soil remediation, reduce energy waste, and avoid geological damage.

[0005] The present invention adopts the following technical solution:

[0006] A steam injection well with a monitoring function, wherein a well pipe is arranged in the well, wherein the well pipe comprises a solid pipe, a screen pipe and a sedimentation pipe in order from top to bottom, a plug is arranged at the lower end of the sedimentation pipe; a screen mesh is coated on the outer side of the screen pipe, and quartz sand is wrapped at the screen pipe and the sedimentation pipe; the upper end of the solid pipe is sealed, and a temperature sensor for monitoring the temperature in the well, a liquid level sensor for monitoring the liquid level in the well and a pressure sensor for monitoring the steam pressure in the well are installed thereon; a sealing soil layer for preventing steam leakage is filled between the solid pipe and the soil, and a steam injection pipe is also arranged at the upper part of the solid pipe.

[0007] The temperature sensor is an armored temperature sensor, which includes a first temperature sensor, a second temperature sensor and a third temperature sensor. The sensor probe of the first temperature sensor extends to the upper position of the real pipe, the sensor probe of the second temperature sensor extends to the lower position of the real pipe, and the sensor probe of the third temperature sensor extends to the lower position of the screen pipe.

[0008] Preferably, the length of the screen tube is 0.5 m to 1 m.

[0009] Preferably, the solid pipe extends upward out of the ground, and the steam injection pipe is installed at a position above the ground of the solid pipe in an upwardly inclined manner.

[0010] Furthermore, a fixed flange is installed at the upper end of the real tube, and the liquid level sensor is a flange-type liquid level sensor. The fixed flange and the connecting flange of the liquid level sensor are fixedly connected by a tightening connector. Through holes with internal threads are provided at intervals on the fixed flange and the connecting flange. The compensation wires of the temperature sensor and the liquid level sensor pass through the through holes and are sealed with the through hole threads through a quick connector.

[0011] Furthermore, the solid pipe is provided with a pressure monitoring joint arranged perpendicularly thereto, and the pressure sensor is installed at the end of the pressure monitoring joint.

[0012] Further preferably, the solid tube, the screen tube and the sedimentation tube are connected in series via a sleeve with threads.

[0013] The technical solution of the present invention has the following advantages:

[0014] A. The present invention adds temperature, pressure and water level monitoring in the steam injection well, which can monitor the high temperature and high pressure environment in the well in real time, ensure that the steam temperature meets the technical requirements, avoid overpressure causing damage to the well structure or formation, and ensure that the steam can be smoothly injected to the target depth of the contaminated area, thereby improving the effect and safety of soil remediation.

[0015] B. The steam injection well provided by the present invention extends the sensing element of the liquid level sensor to a position close to the lower end of the screen tube to ensure that the water level remains below the screen tube and avoid flash evaporation caused by the contact between water and steam. If the downhole liquid level is detected to be too high, a mixed gas of air and steam can be injected to lower the water level below the screen tube through the pressure of the mixed gas to ensure that the steam is smoothly injected into the contaminated soil; at the same time, the pressure sensor monitors the pressure in the well in real time, so as to adjust the injection pressure of steam or mixed gas as needed to ensure the efficient operation of the steam injection well.

[0016] C. The steam injection well structure of the present invention can effectively prevent mud and sand from entering the screen pipe and ensure the sealing and stability of the steam in the well. The well pipe is sealed with a variety of fillers, and the flange-type liquid level sensor and temperature sensor ensure the sealing of the well; the steam injection joint is welded obliquely to reduce turbulence and pressure loss, thereby improving the injection efficiency of the system.

[0017] D. The present invention can monitor the underground environment in real time. By monitoring the underground temperature, pressure and liquid level, the steam injection parameters can be adjusted in real time to ensure that the injection wells operate under efficient and stable conditions, effectively improve the quality of soil remediation, reduce energy waste, and avoid geological damage. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the specific embodiments of the present invention, the drawings required for use in the specific embodiments will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0019] Figure 1 It is a structural diagram of the steam injection well provided by the present invention;

[0020] Figure 2 yes Figure 1 The upper partial schematic diagram shown;

[0021] Figure 3 It is a schematic diagram of the structure of the flange type liquid level sensor provided by the present invention;

[0022] Figure 4 yes Figure 3 The schematic diagram of the fixed flange structure is shown in;

[0023] Figure 5 It is a schematic diagram of the structure of the temperature sensor provided by the present invention.

[0024] The following are marked in the figure:

[0025] 1-well pipe

[0026] 11- solid tube, 12- screen tube, 13- sedimentation tube, 14- plug

[0027] 2- Temperature sensor

[0028] 21-first temperature sensor, 22-second temperature sensor, 23-third temperature sensor

[0029] 2a-sensor probe, 2b-threaded connector, 2c-temperature compensation wire

[0030] 3-Liquid level sensor

[0031] 31-sensing element, 32-connecting flange, 33-liquid level compensation wire

[0032] 4-pressure sensor; 5-quartz sand; 6-steam injection pipe; 7-sealing soil layer

[0033] 8-Fixed flange; 9-Quick connector; 10-Pressure monitoring connector; 20-Bentonite ball

[0034] a-Through hole. DETAILED DESCRIPTION

[0035] The technical solution of the present invention will be described clearly and completely below in conjunction with the accompanying drawings. Obviously, the described embodiments are only 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.

[0036] In the description of the present invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first", "second", and "third" are used for descriptive purposes only, and cannot be understood as indicating or implying relative importance.

[0037] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" 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 a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0038] like Figure 1 , Figure 2As shown, the present invention provides a steam injection well with monitoring function, in which a well pipe 1 is provided in the steam injection well, and the well pipe 1 includes a solid pipe 11, a screen pipe 12 and a sedimentation pipe 13 from top to bottom. Preferably, the solid pipe 11, the screen pipe 12 and the sedimentation pipe 13 are connected in series through a sleeve with a thread to form the well pipe 1, and a plug 14 is provided at the lower end of the sedimentation pipe 13, preferably an elliptical plug; the outer side of the screen pipe 12 is covered with a screen (not shown in the figure) to prevent mud and sand from entering the screen pipe 12, and the screen pipe 12 and the sedimentation pipe 13 are wrapped with quartz sand 5, and the length of the screen pipe 12 is preferably 0.5m to 1m. The upper end of the solid pipe 11 is sealed, and a temperature sensor 2 for monitoring the temperature in the well, a liquid level sensor 3 for monitoring the liquid level in the well, and a pressure sensor 4 for monitoring the steam pressure in the well are installed thereon. A sealing soil layer 7 for preventing steam leakage is filled between the solid pipe 11 and the soil, preferably concrete sealing, and a steam injection pipe 6 is also provided at the upper part of the solid pipe 11.

[0039] In the solid pipe part, it is composed of 20 bentonite balls and 0.5m of concrete, which plays a sealing role to prevent steam leakage from the filler area.

[0040] The preferred temperature sensor 2 of the present invention is an armored temperature sensor, which includes a first temperature sensor 21, a second temperature sensor 22 and a third temperature sensor 23. The sensor probe 2a of the first temperature sensor 21 extends to the upper position of the solid pipe 11, the sensor probe 2a of the second temperature sensor 22 extends to the lower position of the solid pipe 11, and the sensor probe 2a of the third temperature sensor 23 extends to the lower position of the screen pipe 12, so as to realize real-time monitoring of the temperature of three positions in the well. The sensing element 31 of the liquid level sensor 3 extends to the lowest position close to the screen pipe 12, and is used to detect whether the water level in the soil reaches the position of the screen pipe 12. The liquid level sensor 3 can monitor the liquid level in the well in real time to ensure that the liquid level remains below the screen pipe 12, so as to avoid the flash gas generated by the contact between steam and water due to the excessively high water level, which hinders the effective injection of steam. If the liquid level in the well is too high and cannot naturally drop below the screen pipe 12, it is necessary to inject a mixed gas of air and steam, and use the air pressure to reduce the liquid level to below the screen pipe 12, so as to ensure that the steam enters the contaminated soil smoothly. At the same time, the pressure sensor 4 can monitor the pressure in the well, so as to adjust the pressure of the steam injection equipment or the mixed gas according to actual needs, and ensure efficient operation under appropriate pressure conditions.

[0041] like Figures 2 to 4As shown, a fixed flange 8 is installed at the upper end of the solid tube 11, and the liquid level sensor 3 is preferably a flange type liquid level sensor. The fixed flange 8 is fixedly connected to the connecting flange 32 of the liquid level sensor 3 through a fastening connector. Through holes a with internal threads are provided at intervals on the fixed flange 8 and the connecting flange 32. The compensation wires of the three temperature sensors 2 pass through the corresponding through holes a and are threadedly sealed with the through holes a through the quick connector 9. The PM20-SM20C quick connector is used. Figure 5 As shown, the temperature sensor 2 includes a sensor probe 2a, a threaded joint 2b and a temperature compensation wire 2c. The two ends of the temperature compensation wire 2c are respectively connected to the sensor probe 2a and the threaded joint 2b. After the sensor probe 2a is inserted into the set position in the well pipe 1, the threaded joint 2b is installed in the through hole a, and the threaded joint 2b is connected to the quick connector 9. Figure 4 In the middle through hole and the three surrounding through holes.

[0042] Figure 1 A steam injection pipe 6 is arranged in an upwardly inclined manner, which is directly welded to the solid pipe 11 at an angle of 30° by a DN25 external thread. The oblique welding is intended to reduce the turbulence and pressure loss that may be generated when steam is vertically injected, and ensure the stability of steam pressure and temperature.

[0043] In addition, a pressure monitoring joint 10 is provided on the real pipe 11 and is arranged vertically therewith. The pressure sensor 4 is installed at the end of the pressure monitoring joint 10. The pressure monitoring joint 10 is directly vertically welded to the real pipe 11 by a DN15 external thread and is connected to a pressure gauge to monitor the pressure changes in the well.

[0044] The present invention can effectively prevent mud and sand from entering the well, while ensuring the sealing of the steam in the well and monitoring of the pressure and temperature, thereby achieving a more reliable soil restoration effect.

[0045] The basic workflow is as follows:

[0046] (1) Drilling a wellbore with a drilling rig, the wellbore diameter is φ114mm~120mm;

[0047] (2) Lower the well pipe into the wellbore. One side of the sedimentation pipe is threaded, and the other end is welded to an elliptical plug and lowered into the wellbore. The remaining steel pipes that make up the well pipe are threaded, and the threads are tightened during the lowering process.

[0048] (3) After the well pipe is lowered, filler is added. First, quartz sand is added to 0.5m above the screen pipe, then bentonite balls are added and water is added to expand them, and finally 0.5m concrete is added for plugging;

[0049] (4) Weld the DN25 external thread joint at an angle of 30° and the DN15 external thread joint vertically on the well pipe to form a steam injection joint and a pressure monitoring joint;

[0050] (5) The fixed flange welded on the top of the well pipe is used to connect the flange-type liquid level sensor, insert the temperature sensor and liquid level sensor, connect the two flanges, and insert the PM20 connector into the SM20 connector;

[0051] (6) Connect the pressure gauge, steam injection pipe, and sensor to transmit signals.

[0052] The present invention can monitor the underground environment in real time by adding temperature, pressure and water level monitoring sensors to the well pipe. Through real-time underground monitoring, steam injection parameters can be adjusted immediately to ensure that the steam injection system operates under efficient and stable conditions, effectively improve soil remediation quality, reduce energy waste, and avoid geological damage.

[0053] Anything not described in the present invention is applicable to the prior art.

[0054] Obviously, the above embodiments are merely examples for the purpose of clear explanation, and are not intended to limit the implementation methods. For those skilled in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to list all the implementation methods here. However, the obvious changes or modifications derived therefrom are still within the scope of protection of the present invention.

Claims

1. A steam injection well with monitoring function, wherein a well pipe (1) is provided in the well, characterized in that: The well pipe (1) comprises, from top to bottom, a solid pipe (11), a screen pipe (12) and a sedimentation pipe (13), a plug (14) being arranged at the lower end of the sedimentation pipe (13); the outer side of the screen pipe (12) is covered with a screen mesh, and the screen pipe (12) and the sedimentation pipe (13) are wrapped with quartz sand (5); the upper end of the solid pipe (11) is sealed, and a temperature sensor (2) for monitoring the temperature in the well, a liquid level sensor (3) for monitoring the liquid level in the well, and a pressure sensor (4) for monitoring the steam pressure in the well are installed thereon; a sealing soil layer (7) for preventing steam leakage is filled between the solid pipe (11) and the soil, and a steam injection pipe (6) is also arranged at the upper part of the solid pipe (11).

2. The steam injection well with monitoring function according to claim 1, characterized in that: The temperature sensor (2) is an armored temperature sensor, comprising a first temperature sensor (21), a second temperature sensor (22) and a third temperature sensor (23); the sensor probe (2a) of the first temperature sensor (21) extends to the upper position of the solid pipe (11), the sensor probe (2a) of the second temperature sensor (22) extends to the lower position of the solid pipe (11), and the sensor probe (2a) of the third temperature sensor (23) extends to the lower position of the screen pipe (12).

3. The steam injection well with monitoring function according to claim 1, characterized in that: The sensing element (31) of the liquid level sensor (3) extends to a position close to the lowermost end of the screen tube (12).

4. The steam injection well with monitoring function according to claim 1, characterized in that: The length of the screen tube (12) is 0.5m to 1m.

5. The steam injection well with monitoring function according to claim 1, characterized in that: The solid pipe (11) extends upward from the ground, and the steam injection pipe (6) is installed at a position above the ground of the solid pipe (11) in an upwardly inclined manner.

6. The steam injection well with monitoring function according to claim 1, characterized in that: A fixing flange (8) is installed at the upper end of the solid tube (11); the liquid level sensor (3) is a flange type liquid level sensor; the fixing flange (8) and the connecting flange (32) of the liquid level sensor (3) are fixedly connected via a fastening connector; through holes (a) with internal threads are provided at intervals on the fixing flange (8) and the connecting flange (32); the compensation wires of the temperature sensor (2) and the liquid level sensor (3) pass through the through holes (a) and are threadedly sealed with the through holes (a) via a quick connector (9).

7. The steam injection well with monitoring function according to claim 1, characterized in that: The solid pipe (11) is provided with a pressure monitoring joint (10) arranged perpendicularly thereto, and the pressure sensor (4) is installed at the end of the pressure monitoring joint (10).

8. The steam injection well with monitoring function according to any one of claims 1 to 7, characterized in that: The solid pipe (11), the screen pipe (12) and the sedimentation pipe (13) are connected in series via a sleeve with threads.

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