Water injection well test blowout prevention anti-freezing environment-friendly plug

Abstract

The utility model relates to oilfield production engineering technical field especially, it relates to a kind of injection well test blowout prevention freeze-proof environmental protection plug, mainly solve the problem of well fluid overflow caused by excessive wear of packing at the bottom of plug in prior art.The utility model includes: plug base (1), plug base (1) is installed on blowout prevention oil pipe, the upper end of plug base (1) is connected with first pressure relief buffer tank (2) by thread, pressure-resistant packing A (10) is equipped between plug base (1) and first pressure relief buffer tank (2), plug base (1) and first pressure relief buffer tank (2) are connected by center hole, first pressure relief buffer tank (2) side wall is fixed quick coupling B (6), quick coupling B (6) is connected overflow pipe B (13), overflow pipe B (13) is connected with collecting tank (7).The plug solves the problem of well fluid overflow caused by excessive wear of packing at the bottom of original plug, and when downhole pressure is too large, it can realize pressure relief overflow, to avoid environmental pollution.

Description

Technical Field

[0001] This utility model relates to the field of oilfield production engineering technology, and in particular to an environmentally friendly anti-blowout and anti-freezing plug for water injection well testing. Background Technology

[0002] During stratified testing of injection wells, the blowout preventer (BOP) is installed on the test gate of the Christmas tree, serving as an external connection between the downhole testing instruments and the downhole tubing. In practice, when issues such as excessive wear of the packing at the bottom of the plug, increased downhole pressure, or wire corrosion occur, well fluid will overflow from the wire through-hole in the gland cap. The resulting wastewater control and collection is ineffective, and any leakage will pollute the well site and surrounding environment. During winter testing, when outdoor temperatures drop below -20°C, the packing's elasticity decreases due to temperature, resulting in poor sealing and well fluid overflow. Simultaneously, the testing instruments become difficult to lower into the well under the pressure of the backflow, affecting testing efficiency and the injection rate of single wells, thus restricting production and impacting crude oil output. Therefore, to address these shortcomings, a blowout preventer, antifreeze, and environmentally friendly plug for water injection well testing is proposed. Summary of the Invention

[0003] The purpose of this invention is to provide an environmentally friendly anti-blowout and anti-freezing plug for water injection well testing, overcoming the problem of well fluid overflow caused by excessive wear of the packing at the bottom of the plug in existing technologies. This invention proposes an environmentally friendly anti-blowout and anti-freezing plug for water injection well testing. This anti-blowout plug solves the problem of well fluid overflow caused by excessive wear of the packing at the bottom of the plug in existing technologies, and can also achieve pressure relief and overflow when the downhole pressure is too high, avoiding environmental pollution.

[0004] To achieve the above objectives, this utility model provides an environmentally friendly anti-blowout and anti-freezing plug for water injection well testing, comprising: a plug base, the plug base being installed on the anti-blowout pipe, the upper end of the plug base being threadedly connected to a primary pressure relief buffer tank, a pressure-resistant packing A being provided between the plug base and the primary pressure relief buffer tank, the plug base and the primary pressure relief buffer tank being connected through a central channel, a quick connector B being fixed to the side wall of the primary pressure relief buffer tank, the quick connector B being connected to an overflow pipe B, and the overflow pipe B being connected to a sludge collection tank.

[0005] The anti-adsorption plug tube is connected below the central hole of the plug base.

[0006] The upper end of the primary pressure relief buffer tank is connected to the secondary pressure relief buffer tank via a thread.

[0007] A pressure-resistant packing B is provided between the primary pressure relief buffer tank and the secondary pressure relief buffer tank, and the primary pressure relief buffer tank and the secondary pressure relief buffer tank are connected by a central channel.

[0008] The upper end of the secondary pressure relief buffer tank is connected to the upper pressure cover by a thread, and a pressure-resistant packing C is provided between the secondary pressure relief buffer tank and the upper pressure cover.

[0009] The secondary pressure relief buffer tank has a fixed quick connector A on its side wall, which is connected to the overflow pipe A. The overflow pipe A is connected to the sludge collection tank.

[0010] A hexagonal prism nut connects the primary pressure relief buffer tank and the secondary pressure relief buffer tank, and a hexagonal prism nut connects the secondary pressure relief buffer tank and the upper pressure cover.

[0011] This utility model has the following beneficial effects: The environmentally friendly anti-blowout and anti-freezing plug provided by this utility model for water injection well testing adopts a graded overflow reduction structure design. When the pressure-resistant packing inside the plug is worn too much, the hexagonal prism nut on the top of the first-stage pressure relief buffer tank is tightened clockwise. The pressure-resistant packing inside the plug is compressed by the first-stage pressure relief buffer tank. At this time, the channel gap is closed, and the overflow is reduced to zero. During the tightening process, the overflowing sewage flows into the sludge collection tank through the overflow pipe of the first-stage pressure relief buffer tank. The same applies to the second-stage pressure relief buffer tank. When using in winter, add machine oil to the second-stage pressure relief buffer tank to ensure sealing. The machine oil film forms on the sealing gasket and its components, which plays a role in preventing freezing and clogging. The anti-adsorption plug tube is installed on the plug base to avoid the vacuum space created by the tight fit between the bottom of the plug and the lower end of the instrument. By installing the anti-adsorption plug tube, the flow channel is opened, and the pressure inside the entire blowout preventer is unified. The vacuum state is broken, and the instrument is prevented from being adsorbed, so that the instrument can be lowered normally from the wellhead, ensuring the smooth progress of the test process and not affecting subsequent production. Therefore, this invention solves the problem of well fluid overflow caused by excessive wear of the packing at the bottom of the plug in the prior art. Furthermore, it can achieve pressure relief and overflow when the downhole pressure is too high, avoiding environmental pollution. It can also relieve pressure and overflow when the downhole pressure is too high without causing adhesion to downhole instruments, thus allowing the instruments to be smoothly lowered into the well. The use of this invention saves a significant amount of manpower and resources during testing, improves testing efficiency, reduces production costs and the labor intensity of workers, achieving the goal of cost reduction and efficiency improvement. Attached Figure Description

[0012] Figure 1 This is a schematic diagram of the structure of the anti-blowout and anti-freezing environmentally friendly plug for testing water injection wells according to a utility model embodiment;

[0013] Legend: 1-Plug base; 2-First-stage pressure relief buffer tank; 3-Second-stage pressure relief buffer tank; 4-Quick connector A; 5-Overflow pipe A; 6-Quick connector B; 7-Sludge collection tank; 8-Upper pressure cap; 9-Anti-adsorption plug tube; 10-Pressure-resistant packing A; 11-Pressure-resistant packing B; 12-Pressure-resistant packing C; 13-Overflow pipe B. Detailed Implementation

[0014] The present invention will now be described in detail with reference to the accompanying drawings and embodiments. The technical solutions in the embodiments of the present invention will be clearly and completely described. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of the present invention.

[0015] In the description of this utility model, it is necessary to understand that the orientation or positional relationship indicated by terms such as "upper", "lower", "left", "right", "inner", "outer", "top", and "bottom" are all based on the orientation or positional relationship shown in the accompanying drawings. The purpose is only to facilitate the description of this utility model and simplify the description, and is not intended to indicate or imply that the indicated component must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, it should not be construed as a limitation of this utility model.

[0016] Figure 1 This is a schematic diagram of the structure of an environmentally friendly anti-blowout and anti-freezing plug for testing water injection wells, as described in this utility model embodiment. Figure 1 As shown, this utility model provides an environmentally friendly anti-blowout and anti-freezing plug for water injection well testing, including a plug base 1. The plug base 1 is installed on the anti-blowout pipe. The upper end of the plug base 1 is connected to a primary pressure relief buffer tank 2 via a thread. A pressure-resistant packing A10 is provided between the plug base 1 and the primary pressure relief buffer tank 2. The pressure-resistant packing A10 is located in the inner hole at the upper end of the plug base 1. The primary pressure relief buffer tank 2 is threaded to the upper part of the inner hole, and the upper end of the primary pressure relief buffer tank 2 is a hexagonal prism nut. The primary pressure relief buffer tank 2 is used to tighten the hexagonal prism nut with a special wrench when the packing inside the plug base 1 is worn too much, causing the seal to fail. Under the action of the hexagonal prism nut, the pressure-resistant packing is compressed to achieve a sealing operation.

[0017] The pressure-resistant packing A10 is used to achieve a sealing operation under the pressure of the primary pressure relief buffer tank 2 when the pressure-resistant packing at the bottom of the plug base 1 fails. The plug base 1 and the primary pressure relief buffer tank 2 are connected by a central channel to facilitate the passage of steel wire and cable. A quick connector B6 is fixed to the side wall of the primary pressure relief buffer tank 2. The quick connector B6 is used to discharge the overflow well fluid and air carried by the overflow well fluid of the primary pressure relief buffer tank 2. The quick connector B6 is connected to the overflow pipe B13, which is used to transport the overflow well fluid and air carried by the overflow well fluid of the primary pressure relief buffer tank 2. The overflow pipe B13 is connected to the sludge collection tank 7, which is used to collect the overflow well fluid and air carried by the overflow well fluid of the primary pressure relief buffer tank 2.

[0018] Below the central channel of the plug base 1 is an anti-adsorption plug tube 9. The anti-adsorption plug tube 9 effectively solves the problem of the rope cap head not being able to be pressed down when opening and closing the test valve. The anti-adsorption plug tube 9 installed at the bottom of the plug base 1 prevents a vacuum space from forming between the rope caps and opens the flow channel, achieving uniform pressure throughout the blowout preventer. After the blowout preventer plug is connected, the test valve is opened, and well fluid quickly enters the blowout preventer. Simultaneously, the air inside the tube is rapidly compressed and discharged from the top of the plug to the pressure relief buffer tank, and then discharged through the quick connector and overflow pipe. In the prior art, without the anti-adsorption plug tube 9, the top of the rope cap head and the bottom of the plug would tightly adhere after the air inside the blowout preventer is discharged, resulting in a gas-liquid pressure difference inside and outside the blowout preventer. The instrument would then be adsorbed onto the bottom of the plug, affecting subsequent production. Therefore, manual intervention is necessary. By installing the anti-adsorption plug tube 9, the flow channel is opened, achieving uniform pressure throughout the blowout preventer. The vacuum state is broken, thus eliminating adsorption and ensuring the instrument is lowered normally from the wellhead, guaranteeing normal production operation.

[0019] The upper end of the primary pressure relief buffer tank 2 is connected to the secondary pressure relief buffer tank 3 via a thread. The secondary pressure relief buffer tank 3 is used when the pressure-resistant packing A10 inside the primary pressure relief buffer tank 2 is worn too much, causing the seal to fail. By using a special wrench to tighten the hexagonal prism nut, the pressure-resistant packing is pressed together under the action of the hexagonal prism nut to achieve a sealing operation.

[0020] A pressure-resistant packing B11 is provided between the primary pressure relief buffer tank 3 and the secondary pressure relief buffer tank 3. The pressure-resistant packing B11 is located in the upper inner hole of the primary pressure relief buffer tank 2. The secondary pressure relief buffer tank 3 is threaded to the upper part of the inner hole, and the upper end of the secondary pressure relief buffer tank 3 is also a hexagonal prism nut. When the pressure-resistant packing A10 inside the plug base 1 fails to seal, the hexagonal prism nut at the upper end of the secondary pressure relief buffer tank 3 is turned clockwise using a special wrench. Under the action of the hexagonal prism nut, the secondary pressure relief buffer tank 3 presses the pressure-resistant packing B11 inside the primary pressure relief buffer tank 2 to achieve a sealing operation.

[0021] The upper end of the secondary pressure relief buffer tank 3 is connected to the upper pressure cover 8 by a thread. The upper pressure cover 8 is used to seal the secondary pressure relief buffer tank 3. A pressure-resistant packing C12 is provided between the secondary pressure relief buffer tank 3 and the upper pressure cover 8. The pressure-resistant packing C12 is used to seal the secondary pressure relief buffer tank 3.

[0022] The secondary pressure relief buffer tank 3 has a fixed quick connector A4 on its side wall. The quick connector A4 is used to discharge the overflow well fluid and air carried by the overflow well fluid from the primary pressure relief buffer tank 2. The quick connector A4 is connected to an overflow pipe A5. The quick connector A4 is used to discharge the overflow well fluid and air carried by the overflow well fluid from the secondary pressure relief buffer tank 3. The overflow pipe A5 transports and discharges the overflow well fluid and air carried by the overflow well fluid from the secondary pressure relief buffer tank 3. The overflow pipe A5 is connected to a sludge collection tank 7. The sludge collection tank 7 is used to collect the overflow well fluid and air carried by the overflow well fluid from the secondary pressure relief buffer tank 3.

[0023] A hexagonal prism nut connects the primary pressure relief buffer tank 2 and the secondary pressure relief buffer tank 3. A hexagonal prism nut also connects the secondary pressure relief buffer tank 3 and the upper pressure cover 8. The hexagonal prism nut is used to tighten the pressure relief buffer tank with a special wrench when the pressure-resistant packing A10 of the plug base is worn too much and the seal fails. At this time, the pressure relief buffer tank will press the pressure-resistant packing downward under the action of the hexagonal prism nut.

[0024] In practice, the total length of the blowout preventer and antifreeze environmentally friendly plug used for testing water injection wells is 450mm, with an external leakage length of 320mm and a maximum outer diameter of 80mm. The base thread directly connects to the blowout preventer tubing coupling. Due to the relatively high height of the plug, the distance between the tangent of the bottom edge of the pulley and the base should be ≥450mm. If it is less than 450mm, it will restrict installation and use, and the steel wire will not be perpendicular to the longitudinal tangent of the pulley, which may cause the plug to cut the steel wire when the instrument is lowered into the well. Measurements show that the distance between the tangent of the bottom edge of the cable pulley and the base is 520mm, which fully meets the usage requirements. Therefore, it must be used in conjunction with cable pulleys.

[0025] In practice, after the blowout preventer plug is installed, the test gate is opened, and the downhole pressure is directly transmitted to the bottom of the plug. The injected water cannot be released due to the pressure-resistant packing inside the plug base 1. Using a special wrench, the hexagonal nut on the top of the primary pressure relief buffer tank 2 is tightened clockwise. The pressure-resistant packing A10 inside the plug base 1 is compressed, and the channel gap is sealed, reducing the overflow to zero. During the closing process, the overflowing sewage flows into the surface collection tank 7 through the overflow pipe A5 connected to the primary pressure relief buffer tank 2. When the bottom packing completely fails during the instrument's operation downhole, the secondary pressure relief buffer tank 3 also plays a corresponding role, and the upper pressure cap 8 provides a secondary seal, ensuring that sewage does not overflow from the top of the pressure cap. After this test, all packing parts are replaced to ensure normal production operation.

[0026] During winter operations, adjust the tightness of each component of the plug on the ground, add 20ml of machine oil to the secondary pressure relief buffer tank 3 to ensure secondary sealing, lubricate components such as steel wire and cable, and ensure that no water is carried when the steel wire or cable is lifted or lowered, forming an oil film to prevent freezing and blockage.

[0027] This utility model provides an environmentally friendly anti-blowout and anti-freezing plug for testing water injection wells. The device has a simple structure. The plug base 1 is installed on the blowout preventer pipe. The upper end of the plug base 1 is connected to a primary pressure relief buffer tank 2 via a thread. A pressure-resistant packing A10 is provided between the plug base 1 and the primary pressure relief buffer tank 2. The plug base 1 and the primary pressure relief buffer tank 2 are connected through a central channel. A quick connector B6 is fixed to the side wall of the primary pressure relief buffer tank 2. The quick connector B6 is connected to an overflow pipe B13, and the overflow pipe B13 is connected to a sludge collection tank 7. A special wrench is used. Tighten the hexagonal nut at the top of the primary pressure relief buffer tank 2 by hand. At this time, the pressure-resistant packing A10 of the plug base 1 is compressed, the channel gap is sealed, and the overflow flow is reduced to zero. During the closing process, the overflowing sewage and gas flow into the sludge collection tank 7 on the ground through the overflow pipe of the buffer tank. When the primary pressure relief buffer tank 2 fails, tighten the hexagonal nut at the top of the secondary pressure relief buffer tank 3. The secondary pressure relief buffer tank 3 plays a secondary sealing role. The staged pressure reduction and overflow reduction structure design of this device ensures that there is no risk of well fluid overflow and release, and minimizes the occurrence of environmental accidents. The two pressure relief buffer tanks set on the bottom plug of the water injection well anti-blowout and anti-freeze environmental protection plug seal the well fluid overflow channel in stages. Under the action of the sealing packing, a large amount of well fluid is prevented from rising. A small amount of well fluid completely loses kinetic energy through the primary and secondary pressure relief buffer tanks and can only flow out from the overflow pipe and be collected by the sludge collection tank. The testing instrument can be lowered normally inside the wellbore under the influence of gravity, injection pressure, and top lubrication, without being restricted by the packing seal, thus creating favorable conditions for testing and production. Therefore, this utility model solves the problem of well fluid overflow caused by excessive wear of the packing at the bottom of the plug in the prior art, and can achieve pressure relief and overflow when the downhole pressure is too high, avoiding environmental pollution.

[0028] The various embodiments of the present invention have been described above. These descriptions are exemplary and not exhaustive, nor are they limited to the disclosed embodiments. Many modifications and variations will be apparent to those skilled in the art without departing from the scope and spirit of the described embodiments. The terminology used herein is chosen to best explain the principles, practical applications, or technical improvements to the embodiments in the market, or to enable others skilled in the art to understand the embodiments disclosed herein.

Claims

1. An environmentally friendly anti-blowout and anti-freezing plug for water injection well testing, comprising: The plug base (1) is characterized in that: the plug base (1) is installed on the anti-spray pipe, the upper end of the plug base (1) is connected to the first-stage pressure relief buffer tank (2) by a thread, a pressure-resistant packing A (10) is provided between the plug base (1) and the first-stage pressure relief buffer tank (2), the plug base (1) and the first-stage pressure relief buffer tank (2) are connected by a central channel, a quick connector B (6) is fixed on the side wall of the first-stage pressure relief buffer tank (2), the quick connector B (6) is connected to the overflow pipe B (13), and the overflow pipe B (13) is connected to the sludge collection tank (7).

2. The environmentally friendly anti-blowout and anti-freezing plug for water injection well testing according to claim 1, characterized in that: The anti-adsorption plug tube (9) is connected below the central hole of the plug base (1).

3. The environmentally friendly anti-blowout and anti-freezing plug for water injection well testing according to claim 2, characterized in that: The upper end of the primary pressure relief buffer tank (2) is connected to the secondary pressure relief buffer tank (3) by a thread.

4. The environmentally friendly anti-blowout and anti-freezing plug for water injection well testing according to claim 3, characterized in that: A pressure-resistant packing B (11) is provided between the primary pressure relief buffer tank (2) and the secondary pressure relief buffer tank (3), and the primary pressure relief buffer tank (2) and the secondary pressure relief buffer tank (3) are connected by a central channel.

5. The environmentally friendly anti-blowout and anti-freezing plug for water injection well testing according to claim 4, characterized in that: The upper end of the secondary pressure relief buffer tank (3) is connected to the upper pressure cover (8) by a thread, and a pressure-resistant packing C (12) is provided between the secondary pressure relief buffer tank (3) and the upper pressure cover (8).

6. The environmentally friendly anti-blowout and anti-freezing plug for water injection well testing according to claim 5, characterized in that: The side wall of the secondary pressure relief buffer tank (3) is fixed with quick connector A (4), and quick connector A (4) is connected to overflow pipe A (5).

7. The environmentally friendly anti-blowout and anti-freezing plug for water injection well testing according to claim 6, characterized in that: The overflow pipe A (5) is connected to the sludge collection tank (7).

8. The environmentally friendly anti-blowout and anti-freezing plug for water injection well testing according to claim 7, characterized in that: A hexagonal prism nut connects the primary pressure relief buffer tank (2) and the secondary pressure relief buffer tank (3), and a hexagonal prism nut connects the secondary pressure relief buffer tank (3) and the upper pressure cover (8).

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