A wellhead system for production and recharging in the same well and a production and recharging method

Abstract

The present invention belongs to the technical field of production and irrigation in the same well, and specifically discloses a wellhead system for production and irrigation in the same well, including a production device and a recharging device, the production device includes a pressure reducing tank and a water collection pipe connected to the pressure reducing tank, the outside of the pressure reducing tank is provided with a bolt assembly arranged up and down, a winding assembly is provided in the middle position of the bolt assembly, the pressure reducing tank is connected with a manifold through a three-way valve, the manifold is connected with the water collection pipe, a discharge pipe is also provided at one side of the bottom of the pressure reducing tank, and the flat gate valve and the pressure reducing tank are connected through a φ320 casing; the recharging device includes a recharging pipe and a recharging butterfly valve, the recharging butterfly valve is connected with a recharging short section through bolts, and the recharging pipe is connected with the φ320 casing through a three-way valve. The present invention connects the recharging pipe with the casing through a three-way valve, uses a hollow recharging ring pipe formed by casings of different inner diameters as a circulation path for recharging water, connects the recharging water to the recharging short section above the wellhead, and recharging can be achieved, the operation is simple, the number of wellhead disassembly is reduced, and the construction cost is saved.

Description

Technical Field

[0001] The invention belongs to the technical field of production and recharging in the same well, and in particular relates to a production and recharging wellhead system in the same well and a production and recharging method. Background Art

[0002] The geothermal resources currently being developed in my country are mainly medium- and low-temperature hydrothermal geothermal resources. The development method of hydrothermal medium- and low-temperature geothermal resources relies on extracting groundwater to bring up heat energy for people to use. The haze in northern my country is serious, and winter heating has further aggravated the haze. At this stage, there is an urgent need for clean energy heating technology. Geothermal energy, as a clean energy, is increasingly valued in northern heating. At present, the extraction and injection method of hydrothermal geothermal wells is usually different well extraction and injection, that is, one production well needs to correspond to one or more reinjection wells, resulting in huge geothermal development costs.

[0003] Therefore, providing a new wellhead system for production and recharging in the same well and a production and recharging method is a technical problem that needs to be solved urgently by those skilled in the art. Summary of the invention

[0004] The purpose of the present invention is to overcome the defects in the prior art and provide a wellhead system for production and injection in the same well and a production and injection method.

[0005] According to a first aspect of the present invention, a wellhead system for production and injection in the same well is provided, comprising a production device and a reinjection device, wherein the production device comprises a pressure reducing tank 1 and a water production pipe 6 connected to the pressure reducing tank 1, wherein the outer periphery of the pressure reducing tank 1 is provided with bolt assemblies arranged up and down, wherein a winding assembly 3 is provided in the middle position of the bolt assembly, wherein the pressure reducing tank 1 is connected with a manifold 7 through a three-way valve, wherein the manifold 7 is communicated with the water production pipe 6, wherein a discharge pipe is further provided at one side of the bottom of the pressure reducing tank 1, wherein the discharge pipe, the water production pipe 6 and the manifold 7 are all provided with a production butterfly valve 2, wherein a flat gate valve 8 is connected to the lower part of the pressure reducing tank 1, wherein the flat gate valve 8 and the pressure reducing tank 1 are communicated with each other through a φ320 casing; wherein the reinjection device comprises a reinjection pipe 9 and a reinjection butterfly valve 12, wherein the reinjection butterfly valve 12 is connected with a reinjection short section 11 through bolts 10, and wherein the reinjection pipe 9 is communicated with the φ320 casing through a three-way valve.

[0006] A further solution is that the water sampling pipe 6 is provided with an exhaust valve 4 and a pressure gauge assembly 5 .

[0007] A further solution is that the φ320 casing is connected to the φ244.5 casing via a reducer to form a hollow reinjection ring pipe.

[0008] A further solution is that a perspective mirror 15 is provided on the φ320 sleeve, and the perspective mirror 15 is a tempered glass structure.

[0009] A further solution is that the perspective mirror 15 is located at the same level as the recharging pipe 9 .

[0010] A further solution is that a convex bolt is provided on the φ320, and an O-ring is provided inside the convex bolt.

[0011] A further solution is that the convex bolt is arranged at the lower part of the reinjection device to fix the reducer.

[0012] A further solution is that a base flange 14 is provided at the bottom end of the φ320 sleeve.

[0013] The second aspect of the present invention provides a same-well production and reinjection method, which utilizes the above-mentioned same-well production and reinjection wellhead system.

[0014] Further options include mining methods and reinjection methods;

[0015] The mining method comprises the following steps:

[0016] Connect the φ244.5 casing to the φ139.7 casing through a reducer, and extend the φ139.7 casing to the mining area;

[0017] Open the flat gate valve (8), close the exploitation butterfly valves (2) on the discharge pipe and the water extraction pipe (6), and open the exploitation butterfly valve (2) on the confluence pipe (7) to realize gravity water extraction; close the exploitation butterfly valves (2) on the discharge pipe and the confluence pipe (7), and open the exploitation butterfly valve (2) on the water extraction pipe to realize pumping water extraction;

[0018] The recharging method comprises the following steps:

[0019] Close the flat gate valve (8) and apply pressure to the φ139.7 casing to ensure that the packer in the casing is in the open state, thereby isolating the reinjection water and the produced water;

[0020] Open the recharging butterfly valve (12) to supply water to the recharging pipe (9) through the recharging nipple (11);

[0021] The reinjection water enters the well along the hollow reinjection ring pipe and flows into the reinjection area through the reinjection screen pipe.

[0022] Compared with the prior art, the present invention has the following beneficial effects:

[0023] (1) The present invention connects the reinjection pipe with the casing through a three-way valve, and uses a hollow reinjection ring pipe formed by casings of different inner diameters as a flow path for reinjection water. The reinjection water is connected to the reinjection short joint above the wellhead to achieve reinjection. The operation is simple, the number of wellhead disassembly times is reduced, and the construction cost is saved.

[0024] (2) The present invention separates the reinjection water pipeline from the water collection pipeline, and the reinjection water does not pass through the flat gate valve. Compared with the prior art, the reinjection operation is simplified. A perspective mirror made of tempered glass is provided on the casing to clearly observe the flow of the reinjection water. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] The following drawings are only used to illustrate and explain the present invention, and are not used to limit the scope of the present invention, wherein:

[0026] Figure 1 : Schematic diagram of the wellhead system structure for production and irrigation in the same well;

[0027] Figure 2 : Schematic diagram of the structure of the recharging device;

[0028] Figure 3 : Schematic diagram of the side structure of the recharging device;

[0029] In the figure: 1 pressure reducing tank, 2 mining butterfly valve, 3 winding assembly, 4 exhaust valve, 5 pressure gauge assembly, 6 water production pipe, 7 confluence pipe, 8 flat gate valve, 9 reinjection pipe, 10 bolts, 11 reinjection short joint, 12 reinjection butterfly valve, 13 O-ring, 14 base flange, 15 perspective mirror. DETAILED DESCRIPTION

[0030] In order to make the purpose, technical solution, design method and advantages of the present invention clearer, the present invention is further described in detail by specific embodiments in conjunction with the accompanying drawings. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0031] like Figure 1-3 As shown, in the first aspect of the present invention, a wellhead system for production and injection in the same well is provided, including a production device and a reinjection device, the production device including a pressure reducing tank 1 and a water production pipe 6 connected to the pressure reducing tank 1, the outer periphery of the pressure reducing tank 1 is provided with bolt assemblies arranged up and down, and a winding assembly 3 is provided in the middle position of the bolt assembly, the pressure reducing tank 1 is connected to a manifold 7 through a three-way valve, the manifold 7 is communicated with the water production pipe 6, a discharge pipe is also provided on one side of the bottom of the pressure reducing tank 1, the discharge pipe, the water production pipe 6 and the manifold 7 are all provided with a production butterfly valve 2, the lower part of the pressure reducing tank 1 is connected with a flat gate valve 8, the flat gate valve 8 and the pressure reducing tank 1 are communicated through a φ320 casing; the reinjection device includes a reinjection pipe 9 and a reinjection butterfly valve 12, the reinjection butterfly valve 12 is connected to a reinjection short section 11 through bolts 10, and the reinjection pipe 9 is communicated with the φ320 casing through a three-way valve.

[0032] The water sampling pipe 6 is provided with an exhaust valve 4 and a pressure gauge assembly 5 for exhausting the air and relieving the pressure and monitoring the pressure inside the water sampling pipe 6 .

[0033] Optionally, the φ320 casing is connected to a φ244.5 casing through a reducer to form a hollow reinjection ring pipe for reinjection water to flow into the wellbore. The φ320 casing is provided with a perspective mirror 15, which is a tempered glass structure. The perspective mirror 15 is located at the same level as the reinjection pipe 9, so that the flow of reinjection water can be clearly observed.

[0034] Optionally, a convex bolt is provided on the φ320, an O-ring is provided inside the convex bolt, and the convex bolt is provided at the lower part of the recharging device to fix the reducer, thereby ensuring the tight connection and sealing of casings with different inner diameters.

[0035] Optionally, a base flange 14 is provided at the bottom end of the φ320 sleeve for fixing the φ320 sleeve.

[0036] Taking into account the open-air placement of the wellhead and internal corrosion protection issues, the entire wellhead is surface treated with nickel-phosphorus stainless steel inside and outside, making the product overall beautiful and durable.

[0037] The second aspect of the present invention provides a same-well production and reinjection method, which utilizes the above-mentioned same-well production and reinjection wellhead system.

[0038] Further options include mining methods and reinjection methods;

[0039] Specifically, the mining methods include:

[0040] Connect the φ244.5 casing to the φ139.7 casing through a reducer, and extend the φ139.7 casing to the mining area;

[0041] Open the flat gate valve (8), close the exploitation butterfly valves (2) on the discharge pipe and the water extraction pipe (6), and open the exploitation butterfly valve (2) on the confluence pipe (7) to realize gravity water extraction; close the exploitation butterfly valves (2) on the discharge pipe and the confluence pipe (7), and open the exploitation butterfly valve (2) on the water extraction pipe to realize pumping water extraction;

[0042] The recharging method includes the following steps:

[0043] Close the flat gate valve (8) and apply pressure to the φ139.7 casing to ensure that the packer in the casing is in the open state, thereby isolating the reinjection water and the produced water;

[0044] Open the recharging butterfly valve (12) to supply water to the recharging pipe (9) through the recharging nipple (11);

[0045] The reinjection water enters the well along the hollow reinjection ring pipe and flows into the reinjection area through the reinjection screen pipe.

[0046] The embodiments of the present invention have been described above, and the above description is exemplary, not exhaustive, and is not limited to the disclosed embodiments. Many modifications and variations will be apparent to those of ordinary skill in the art without departing from the scope and spirit of the described embodiments. The selection of terms used herein is intended to best explain the principles of the embodiments, practical applications, or technical improvements in the market, or to enable other persons of ordinary skill in the art to understand the embodiments disclosed herein.

Claims

1. A wellhead system for production and irrigation in the same well, characterized in that: The invention comprises an extraction device and a reinjection device, wherein the extraction device comprises a pressure reducing tank (1) and a water extraction pipe (6) connected to the pressure reducing tank (1), wherein the outside of the pressure reducing tank (1) is provided with a bolt assembly arranged up and down, wherein a winding assembly (3) is arranged in the middle of the bolt assembly, wherein the pressure reducing tank (1) is connected to a manifold (7) via a three-way valve, wherein the manifold (7) is communicated with the water extraction pipe (6), and a discharge pipe is also arranged at one side of the bottom of the pressure reducing tank (1), wherein the discharge pipe is provided at the bottom of the pressure reducing tank (1). The water pipe (6) and the confluence pipe (7) are all provided with a production butterfly valve (2); the lower part of the pressure reducing tank (1) is connected with a flat gate valve (8); the flat gate valve (8) and the pressure reducing tank (1) are communicated through a φ320 casing; the reinjection device comprises a reinjection pipe (9) and a reinjection butterfly valve (12); the reinjection butterfly valve (12) is connected with a reinjection short joint (11) through a bolt (10); the reinjection pipe (9) and the φ320 casing are communicated through a three-way valve; The φ320 casing is connected to the φ244.5 casing via a reducer to form a hollow reinjection ring pipe; Connect the reinjection pipe with the casing through a three-way valve, use the hollow reinjection loop formed by casings of different inner diameters as the flow path of reinjection water, and connect the reinjection water to the reinjection nipple above the wellhead to achieve reinjection; The φ320 sleeve is provided with a perspective mirror (15), and the perspective mirror (15) is a tempered glass structure; Same well mining steps: Connect the φ244.5 casing to the φ139.7 casing through a reducer, and extend the φ139.7 casing to the mining area; Open the flat gate valve, close the exploitation butterfly valves on the discharge pipe and the water production pipe, and open the exploitation butterfly valve on the confluence pipe to realize gravity water production; close the exploitation butterfly valves on the discharge pipe and the confluence pipe, and open the exploitation butterfly valve on the water production pipe to realize pumping water production; Steps for reinjection in the same well: Close the flat gate valve and apply pressure to the φ139.7 casing to ensure that the packer inside the casing is in the open state to isolate the reinjection water and produced water; Open the recharging butterfly valve and supply water to the recharging pipe through the recharging nipple; The reinjection water enters the well along the hollow reinjection ring pipe and flows into the reinjection area through the reinjection screen pipe.

2. A wellhead system for production and irrigation in the same well according to claim 1, characterized in that: The water sampling pipe (6) is provided with an exhaust valve (4) and a pressure gauge assembly (5).

3. The wellhead system for production and irrigation in the same well according to claim 1, characterized in that: The perspective mirror (15) is located at the same level as the recharging pipe (9).

4. The wellhead system for production and irrigation in the same well according to claim 1, characterized in that: The φ320 is provided with a convex bolt, and an O-shaped sealing ring is provided inside the convex bolt.

5. A wellhead system for production and irrigation in the same well according to claim 4, characterized in that: The convex bolt is arranged at the lower part of the recharging device and is used to fix the reducer.

6. The wellhead system for production and irrigation in the same well according to claim 1, characterized in that: The bottom end of the φ320 sleeve is provided with a base flange (14).

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