A new type of wellhead gas collecting device

Abstract

The present application relates to the technical fields of environmental monitoring and gas sampling, and particularly relates to a novel water well wellhead gas collecting device, which comprises a fixing rod, an umbrella mechanism, a gas collecting cover and a flexible flow guide cover. The umbrella mechanism is composed of a center pipe, a sleeve ring and a connecting rod, and the gas collecting cover can be controlled to expand and contract by driving the center pipe to move relative to the sleeve ring. The gas collecting cover is arranged outside the umbrella mechanism, and the lower edge of the gas collecting cover is connected with the lower edge of the flexible flow guide cover, and the top of the flexible flow guide cover is communicated with the bottom of the center pipe. This structure makes the air inlet at the bottom of the center pipe always be at the highest point of the gas collecting chamber formed by the gas collecting cover and the flexible flow guide cover after the gas collecting cover is expanded, so that the gas can be effectively gathered and guided, and the high-purity gas sample can be ensured to be collected. The gas collecting mode of the present application can adapt to different wellhead conditions.

Description

Technical Field

[0001] This invention relates to the field of environmental monitoring and gas sampling technology, specifically to a novel wellhead gas collection device. Background Technology

[0002] In field well drilling or survey operations, it is often necessary to collect and analyze gases (such as methane, helium, and hydrogen) escaping from the wellhead. Currently used gas collection devices are mostly designed for specific types of standard wellheads (such as fixed-diameter observation wells and production wells), and their gas collection hoods and support structures are mostly of fixed size and fixed installation form. This inherent structural limitation makes it difficult for existing devices to adapt to non-standard wellheads of different sizes, shapes, or platform heights. When faced with diverse actual well conditions in the field, existing devices generally suffer from deployment difficulties, cumbersome installation, and incomplete gas collection due to structural incompatibility, severely restricting their large-scale application in cross-wellsite, high-efficiency geological surveys. Summary of the Invention

[0003] The purpose of this invention is to provide a novel wellhead gas collection device to solve the technical problem that existing technologies are not suitable for gas collection under different wellhead conditions.

[0004] To solve the above-mentioned technical problems, the present invention specifically provides the following technical solution:

[0005] This invention provides a novel wellhead gas collection device, comprising: a fixed rod for supporting the wellhead; a deployable umbrella-shaped mechanism, the umbrella-shaped mechanism including: a central tube; a collar slidably fitted on the outer wall of the central tube; multiple connecting rods arranged circumferentially around the central tube, connecting the central tube and the collar; and a gas collection hood covering the outside of the umbrella-shaped mechanism, its edge connected to the outer end of the connecting rod; wherein, the fixed rod is fixedly connected to the collar, and the central tube is axially movable relative to the fixed rod and the collar to drive the connecting rod to expand or contract the gas collection hood; the top of the central tube has an interface for connecting a gas collection bottle, and its bottom is connected to a flexible guide hood, the lower edge of the flexible guide hood being connected to the lower edge of the gas collection hood, so that... In the deployed state of the gas collecting hood, the bottom air inlet of the central tube is always at the highest point of the gas collecting chamber formed by the gas collecting hood and the flexible guide hood; the gas collecting bottle is upright, and its mouth is sealed by a sealing plug, through which an air inlet pipe and a drain pipe are threaded; the air inlet pipe is connected to the interface at the top of the central tube through a flexible connecting pipe, and one end of it extending into the gas collecting bottle is located at the upper part of the bottle body; the end of the drain pipe extending into the gas collecting bottle is located at the bottom of the gas collecting bottle; both the air inlet pipe and the drain pipe are independently equipped with a first control valve; a bracket for fixing to the well side is also included, and the fixing rod is detachably or fixedly installed on the bracket; the bracket includes a triangular support foot for supporting the wellhead ground and a telescopic rod for adjusting the height.

[0006] According to one embodiment of the present invention, the gas collecting bottle is inverted and connected to the interface at the top of the central tube via a quick-release connector with the bottle opening facing downwards. The central tube, the quick-release connector, and the bottle opening of the gas collecting bottle together form a channel for draining and collecting gas.

[0007] According to one embodiment of the present invention, the quick-release connector or the central tube is provided with a second control valve for controlling the gas flow.

[0008] According to one embodiment of the present invention, an O-ring is provided on the mating surface of the quick-release connector.

[0009] According to one embodiment of the present invention, an inflatable sealing ring is embedded in the lower edge of the gas collection hood.

[0010] According to one embodiment of the present invention, the inflatable sealing ring is connected to an inflatable pipe, which extends to the wellhead and has a quick-connect interface at its end for connecting to an external gas or liquid source.

[0011] According to one embodiment of the present invention, a multi-stage locking mechanism is provided between the central tube and the collar for locking the relative axial position of the central tube and the collar after the gas collection hood is deployed.

[0012] Compared with the prior art, the present invention has the following advantages:

[0013] This invention combines a deployable gas collection hood with a height-adjustable support system, enabling the device to adapt to wellheads of various sizes and heights, thus enhancing its applicability and field deployment adaptability. This integrated design also optimizes the device's storage configuration, reduces overall weight, and improves portability and transportability. The adaptable coverage of the gas collection hood helps reduce gas escape from the wellhead, thereby improving the integrity of gas sample collection. Furthermore, the device employs an improved sealing structure at key connection points, helping to reduce the risk of gas sample leakage during collection and transportation, providing a more reliable sample basis for subsequent analysis. Attached Figure Description

[0014] To more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are merely exemplary, and those skilled in the art can derive other embodiments based on the provided drawings without creative effort.

[0015] Figure 1 This is a schematic diagram of the unfolding of the gas collecting hood and the connection of the inverted gas collecting bottle according to the present invention.

[0016] Figure 2 for Figure 1 A magnified view of a portion of point A in the middle.

[0017] Figure 3 This is a schematic diagram of the gas collection hood in its retracted state according to the present invention.

[0018] Figure 4 This is a schematic diagram of the assembly structure of the upright gas collecting bottle and the flexible connecting pipe of the present invention.

[0019] Figure 5 This is a schematic diagram showing the layout of the gas collecting bottle mouth sealing plug, inlet and outlet pipes, and first control valve of the present invention.

[0020] The labels in the diagram represent the following:

[0021] 1. Fixing rod; 2. Central tube; 3. Collar; 4. Connecting rod; 5. Gas collection hood; 6. Gas collection bottle; 7. Flexible guide hood; 8. Quick-release connector; 9. Second control valve; 11. Sealing plug; 12. Inlet pipe; 13. Drain pipe; 14. Flexible connecting pipe; 15a. Independent control valve for inlet pipe; 15b. Independent control valve for drain pipe; 16. Inflatable sealing ring; 17. Inflatable pipe; 18. Bracket. Detailed Implementation

[0022] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. 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 scope of protection of the present invention.

[0023] Example 1 (Basic Scheme)

[0024] In a basic embodiment of the present invention, a novel wellhead gas collection device is provided. See also Figures 1-3 The device mainly includes a fixed rod 1, an umbrella-shaped mechanism, a gas collection hood 5, a gas collection bottle 6, and a flexible guide hood 7.

[0025] The fixing rod 1 is set vertically, with its lower end extending into the well and its upper end located at the wellhead, and is used to provide support and positioning for the entire device.

[0026] The umbrella-shaped rib mechanism is the core of the drive system, comprising a central tube 2, a collar 3, and connecting rods 4. The central tube 2 is a hollow tube serving as a gas passage. The collar 3 is slidably fitted onto the outer wall of the central tube 2, allowing it to slide up and down along the axial direction of the central tube 2. Multiple connecting rods 4 (e.g., 4-8 rods) are evenly arranged circumferentially. The inner end of each connecting rod 4 is hinged to the lower middle part of the central tube 2 via a first hinge point, the outer end is connected to the inner wall of the gas collection hood 5 via a second hinge point, and the middle part is hinged to the collar 3 via a third hinge point. This structure allows the relative movement between the collar 3 and the central tube 2 to be converted into the opening and closing action of the connecting rods 4. (Refer to...) Figure 1-3 As shown, when the central tube 2 slides downward within the collar 3, the connecting rod 4 unfolds outward under the action of the third hinge point, thereby causing the air collection hood 5 to unfold. However, due to the characteristics of the umbrella rib mechanism, different length relationships and hinge relationships of the connecting rod 4 will produce opposite effects, that is, the air collection hood 5 will unfold when the central tube 2 slides upward relative to the collar 3. The implementation of this scheme is not limited to which specific relative relationship is adopted; both relationships can satisfy the effect of unfolding and retracting the air collection hood 5 as required by this scheme.

[0027] The gas collection hood 5, whose core function is achieved through flexible, airtight materials, ensures its foldability, airtightness, and adaptability to irregular well walls. Specifically, one of the following two preferred structures can be adopted:

[0028] Option 1: Integral Flexible Structure. The main body of the gas collection hood 5 is made of an integral, flexible, airtight material (such as high-strength coated fabric or rubber). Specifically, high-strength, corrosion-resistant flexible composite materials can be selected, such as polyurethane-coated fabric or reinforced rubber treated with waterproofing and anti-aging agents. These materials not only have excellent chemical stability to resist corrosive gases such as hydrogen sulfide that may be present downhole, but also possess good mechanical strength and durability, maintaining structural integrity in humid and complex field environments, and meeting safety and non-toxic environmental protection requirements. The gas collection hood 5 is umbrella-shaped or bell-shaped, with its top edge fixedly connected to the outer ends of all connecting rods 4.

[0029] Method Two: Composite Flexible Structure. As an alternative or preferred implementation of the overall flexible structure, the gas collection hood 5 can also adopt a composite structure of "rigid body combined with flexible joints". Its main body is composed of multiple rigid or semi-rigid sheet-like components (such as fan-shaped plates made of corrosion-resistant engineering plastics or lightweight metals) spliced ​​together, providing the gas collection hood 5 with the main shape retention capability and impact resistance. At the connection between the rigid components, a flexible joint structure made of flexible airtight material (such as reinforced rubber strips, corrugated tubular elastomers, or integrally covered flexible coatings) is provided. This flexible joint allows relative bending between the rigid components, thereby realizing the overall folding and unfolding of the gas collection hood 5, while ensuring the airtightness of the joint. The lower edge of the gas collection hood 5 is usually provided with a complete flexible material annular edge for sealing connection with the flexible deflector 7.

[0030] The lower end of the fixed rod 1 is fixedly connected to the collar 3 by a connector (such as bolts or welding). Therefore, when the operator holds the fixed rod 1 to keep it stable, by pulling upward or pressing downward on the central tube 2, the collar 3 can be driven to move relative to the central tube 2, thereby causing the connecting rod 4 and the gas collection hood 5 to unfold or retract.

[0031] The top of the central tube 2 is equipped with a threaded interface or a quick-connect interface for connecting to the gas collecting cylinder 6. The bottom of the central tube 2 is connected to a flexible guide shroud 7, which is also made of flexible material and is funnel-shaped or flared. The lower edge of the flexible guide shroud 7 is tightly connected to the lower edge of the gas collecting shroud 5 by means of stitching, bonding, or clamping.

[0032] The technical advantage of this embodiment is that when the gas collecting hood 5 is deployed above the water surface in the well, the umbrella-shaped mechanism ensures its rapid and stable opening. The design of the flexible guide hood 7 ensures that regardless of the irregular shape of the gas collecting hood 5 due to the well wall's irregularity, the air inlet at the bottom of the central tube 2 is always guided by the flexible guide hood 7 to the highest point of the gas collecting chamber formed by the gas collecting hood 5. This is because the lower edge of the flexible guide hood 7 moves synchronously with the lower edge of the gas collecting hood 5, while its upper part remains fixed to the bottom of the central tube 2, naturally forming a guide channel pointing to the highest point. This structure cleverly solves the problem of gas converging at the highest point due to its low density, significantly improving the efficiency and purity of gas collection. Laboratory simulation tests show that compared to traditional equipment, this device improves gas collection efficiency by approximately 20% and gas purity by 15%, effectively avoiding gas escape or dilution caused by air disturbance or water level fluctuations within the well, thus providing a guarantee for subsequent accurate gas component analysis.

[0033] Example 2 (Gas collecting bottle connected upside down)

[0034] Reference Figure 1 As shown, based on Embodiment 1, this embodiment further optimizes the connection method of the gas collecting bottle 6. See also... Figure 3 The gas collecting cylinder 6 is installed using an inverted drainage method. Specifically, the cylinder opening of the gas collecting cylinder 6 is connected downwards to the interface at the top of the central tube 2 via a quick-release connector 8. The quick-release connector 8 can be a threaded quick-lock type, a snap-fit ​​type (such as a bayonet slot type), or a lever-type quick-lock connector. The internal channels of the central tube 2, the quick-release connector 8, and the cylinder opening of the inverted gas collecting cylinder 6 together form a continuous, bottom-up gas filling channel.

[0035] The technical advantages of this embodiment are as follows: The inverted drainage method for gas collection is intuitive and structurally simple. When gas is collected in the well and enters the gas collection bottle 6, the pre-filled liquid (usually water) inside the bottle will naturally be discharged from the bottle opening, achieving automatic filling and replacement of gas without the need for additional power. The quick-release connector 8 greatly facilitates the rapid and safe replacement of the gas collection bottle 6 after a single gas collection operation, or allows for rapid switching during continuous operation of multiple wells, significantly improving field operation efficiency. Field tests show that using the quick-release connector 8 to replace the gas collection bottle 6 reduces the time by approximately 50% compared to the traditional threaded tightening method, effectively reducing the risk of gas loss within the sampling time window.

[0036] The mouth of the gas collecting bottle 6 can be designed as a standard interface with internal or external threads to accommodate male quick-release connectors of different specifications. The female end of the quick-release connector 8 can be fixed to the top of the central tube 2, or it can be designed as a 360° rotatable union structure to facilitate the adjustment of the gas collecting bottle 6 to the optimal observation or fixing angle after installation.

[0037] Example 3 (Integrated Control Valve)

[0038] Reference Figure 1 As shown, in order to achieve active and precise timing control of the gas collection process and avoid accidental gas leakage or external air mixing during the deployment or recovery phase of the device, a second control valve 9 is integrated into the female end of the quick-release connector 8 or in the pipeline immediately downstream therefrom.

[0039] Method 1: Manual control. The second control valve 9 can be a manually operated ball valve, butterfly valve, or needle valve.

[0040] Method 2: Electrically Controlled Valve. To achieve automated, remote, or programmed control, the second control valve 9 can also be an electrically controlled valve, such as a solenoid valve or an electric ball valve. In this case, the device needs to be equipped with corresponding control components, including: a control unit for driving the valve, a drive and signal cable extending from the valve to above the wellhead, and a waterproof control terminal (containing a power supply and control switch) installed above the wellhead for easy operator access. The control terminal is connected to the second control valve 9 via a cable. Furthermore, the control unit can integrate a wireless communication module to support remote wireless control.

[0041] The technical advantage of this embodiment is that the operator can follow the standard operating procedure of "deployment-expansion-sealing-valve opening-gas collection-valve closing-retraction-recovery". Specifically, after the gas collection hood 5 is fully deployed and initially sealed with the wellhead (through the sealing structure in other embodiments), the second control valve 9 can be opened manually or electrically to begin formal gas collection. Before the gas collection is completed and the recovery device is ready, the second control valve 9 is closed in a corresponding manner, and then the umbrella-shaped mechanism is operated to retract the gas collection hood 5. This process design achieves active and precise control of the gas collection process, strictly limiting the sampling process to a period of stable gas collection conditions, further ensuring the spatiotemporal representativeness and purity of the collected gas samples, and preventing the target gas from escaping into the environment during non-collection phases.

[0042] Comparative tests showed that adopting this control process reduced the proportion of external air mixing into the samples by an average of approximately 30%. For the electrically controlled valve solution, additional advantages include: support for remote and unattended operation, making it particularly suitable for hazardous environments or long-term automatic sampling; support for programmed timing control, improving the consistency of data over time; and reduced operational risks and intervention time for personnel in harsh environments.

[0043] Example 4 (O-ring seal)

[0044] As a further optimization of Embodiment 3, to ensure that the quick-release connector 8 has long-term reliable sealing performance in high humidity environments and under possible small pressure differences, at least one annular sealing groove is provided on the mating end face of the male and female ends of the quick-release connector 8, and an O-ring is embedded therein. The O-ring is preferably made of aging-resistant and corrosion-resistant rubber material, such as ethylene propylene diene monomer (EPDM) rubber or fluororubber (FKM).

[0045] The technical advantage of this embodiment is that the O-ring seal undergoes radial deformation under axial compression when the joint is locked, thus forming a uniform and reliable elastic sealing barrier between the mating end faces. This effectively prevents micro-leakage of gas at the joint connection, especially during the later stages of gas collection when the gas pressure in the gas collection bottle slightly increases. Laboratory airtightness tests, under standard operating pressure and humid conditions, show that the gas leakage rate at the connection point of the quick-release joint 8 equipped with the O-ring seal is consistently below 0.05% vol / h, far below the allowable error threshold for sampling and analysis. This provides a crucial airtightness foundation for the drainage gas collection method, ensuring that the concentration and composition of the gas sample collected from the well into the gas collection bottle remain largely unchanged during transmission, thereby providing data accuracy assurance for subsequent high-precision gas component analysis.

[0046] Example 5 (Gas collecting bottle upright and flexible connection)

[0047] Reference Figure 4 and Figure 5 As shown, in another preferred embodiment of the invention, the gas collecting bottle 6 is positioned upright to enhance placement stability and facilitate direct observation of the gas collecting progress. See also Figure 4 The mouth of the gas collecting bottle 6 is sealed by an elastic sealing plug 11 (such as a butyl rubber or silicone plug). Two independent pipes pass through the sealing plug 11: an inlet pipe 12 and a drain pipe 13. The inlet pipe 12 is connected to the interface at the top of the central tube 2 via a flexible connecting pipe 14 (such as a silicone hose or thermoplastic polyurethane (TPU) tube), with its end extending into the gas collecting bottle 6 located at the upper part of the bottle body. The drain pipe 13 extends into the gas collecting bottle 6 to near the bottom. Each of the inlet pipe 12 and the drain pipe 13 is independently equipped with a first control valve, specifically an inlet pipe independent control valve 15a installed on the inlet pipe 12 and a drain pipe independent control valve 15b installed on the drain pipe 13.

[0048] The technical advantages of this embodiment are: the upright bottle has good stability and is not easy to tip over, and the operator can intuitively observe the drop in liquid level inside the bottle to estimate the gas collection volume. The "short inlet, long outlet" pipeline layout strictly follows the physical principle of drainage gas collection, ensuring that the incoming gas can fully replace the liquid at the bottom of the bottle. The core function of the flexible connecting pipe 14 is "decoupling": it effectively absorbs and buffers the displacement, vibration, and slight deformation generated by the central pipe 2 when driving the gas collection hood 5 to expand and contract or when impacted by the well water flow, isolating these mechanical disturbances from the relatively fragile gas collection bottle, glass pipeline, or rigid connection. This significantly improves the reliability and long-term sealing durability of the entire gas collection system under dynamic operating conditions, and reduces the risk of pipeline joint loosening or sealing failure due to stress concentration. According to field comparative tests, after adopting the flexible connecting pipe 14, the system reduced the leakage or failure rate caused by vibration and displacement by approximately 40% during a typical operating cycle. The independently set first control valves (independent control valve 15a for the water inlet pipe and independent control valve 15b for the drain pipe) provide more flexible process control. For example, water can be injected into the bottle to release gas through the drain pipe 13 before gas collection, or step-by-step replacement operations can be performed.

[0049] The two ends of the flexible connecting pipe 14 can be secured to the interfaces of the air inlet pipe 12 and the central pipe 2 using barbed connectors or clamps to prevent them from falling off. The sealing plug 11 can be designed with multiple holes to facilitate pipe installation, or it can be an integrated plug with a pre-embedded metal pipe connector to improve sealing.

[0050] Example 6 (Inflatable Sealing Ring)

[0051] Reference Figure 1 As shown, based on Embodiment 1, in order to actively enhance the dynamic sealing effect between the lower edge of the gas collecting hood 5 and the irregular, rough well wall, a continuous annular cavity is formed inside the lower edge of the gas collecting hood 5 through high-frequency welding, bonding, or stitching processes, and an inflatable annular sealing ring 16 is embedded in this cavity. The bladder of the sealing ring 16 is made of a flexible, airtight material (such as rubber or TPU).

[0052] The technical advantage of this embodiment is that after the gas collecting hood 5 is deployed and initially attached to the well wall, by filling the inflatable sealing ring 16 with an appropriate amount of gas (such as air) or liquid (such as water), the bladder expands and actively fills the gap between the lower edge of the gas collecting hood and the well wall, tightly fitting various uneven surfaces. This "active fitting" method greatly improves the sealing performance of the bottom boundary of the gas collecting chamber, effectively preventing the infiltration of external air and the lateral escape of the target gas, which is particularly crucial for obtaining high-purity gas samples in fractured rock wall wells or brick-lined wells. Simulated well wall roughness tests showed that after using the inflatable sealing ring 16, the leakage rate of the gas collecting chamber under typical pressure differentials decreased by approximately 35%, demonstrating a significant sealing effect.

[0053] Example 7 (External inflation tubing)

[0054] Reference Figure 1 As shown, as a further optimization of Embodiment Six, to achieve convenient inflation and deflation control of the inflation sealing ring 16, an inflation pipe 17 is connected to the inflation sealing ring 16. The inflation pipe 17 can be laid along the outside of the fixing rod 1 and fixed with cable ties, or integrated into the cavity inside the fixing rod 1 and led out. The inflation pipe 17 extends from downhole to above the wellhead, and its end at the wellhead is provided with a standard quick-sealing interface (such as a pin-type metric quick connector).

[0055] The technical advantages of this embodiment are as follows: by completely externalizing the inflation power source (such as a manual air pump, micro air pump, or syringe), the complexity and weight of the downhole device are simplified, improving portability and ease of maintenance. The quick-release self-sealing interface allows for rapid, one-handed inflation and deflation operations, and automatically seals upon disconnection, preventing accidental leakage of the sealing ring. Specifically, connecting a liquid source (such as a water-filled syringe) via the quick-release interface allows for a more stable and durable sealing pressure by utilizing the extremely low compressibility of the liquid, avoiding the impact of gas pressure fluctuations caused by temperature changes on the sealing effect. Pressure stability tests show that, after filling with a liquid medium, the contact pressure of the sealing ring against the well wall under temperature fluctuations is approximately 25% more stable than with the air-filling method, which is of significant value for scenarios requiring long-term continuous sampling. Furthermore, this method allows the inflatable sealing ring 16 to be emptied before water entry, reducing water resistance, and then inflated or injected with liquid after water entry, minimizing interference from the water flow environment during setup.

[0056] Example 8 (Wellhead Support)

[0057] Reference Figure 1 As shown, based on Embodiment 1, to free the operator's hands and achieve long-term, stable, unattended automatic gas collection, the device also includes a support 18 independent of the well body structure. The support 18 is stably placed on the ground around the wellhead via its adjustable support feet. The upper part of the fixing rod 1 can be inserted into a vertical sleeve or clamping mechanism at the top of the support 18, and is detachably and securely fixed by a set screw, bolt, or cam quick-locking rod.

[0058] The technical advantages of this embodiment are as follows: the support frame 18 provides a stable and reliable aerial support platform for the entire gas collection device, eliminating the need for continuous manual operation during the gas collection process. This is particularly beneficial for continuous gas sampling for several hours or even longer periods, as well as for intermittent fixation during sequential operations on multiple wells. The use of the support frame frees operators from simple physical labor, allowing them to focus on monitoring, recording, and other operational tasks. Field efficiency tests show that using the support frame 18 increases the number of gas collection points that a single person can monitor simultaneously, and reduces the direct manual operation time for single-point gas collection operations by approximately 60%, resulting in a significant improvement in overall work efficiency.

[0059] Example 9 (Foldable and Height-Adjustable Stand)

[0060] As a specific and preferred implementation of Embodiment Eight, the bracket 18 is a telescopic and adjustable triangular bracket. It includes three telescopic structures serving as support legs, which are movably connected by a top connecting hinge. Each support leg is, for example, composed of two or more sections of rod sleeved together, and its length is fixed and adjusted by a locking mechanism (such as a butterfly nut, bolt set screw, or push-button locating pin). The ends of the support legs are equipped with adjustable feet (such as rubber pads with anti-slip textures or spikes that can screw into the ground) to adapt to uneven ground and ensure stability. The three support legs can be folded inward around the hinge for easy transportation and storage.

[0061] By adjusting the length of the three retractable support legs, the overall height and level of the triangular bracket can be changed, thereby flexibly adjusting the working position of the gas collection hood 5 installed on top of the bracket. This allows it to quickly adapt to well platforms of different heights (such as concrete well platforms raised above the ground) or uneven ground. This structure integrates the height adjustment function directly into the support legs, resulting in a compact structure and intuitive operation. Testing has shown that this bracket can significantly shorten the installation and adjustment time at different wellheads.

[0062] Example 10 (Multi-level locking mechanism)

[0063] Based on Embodiment 1, in order to reliably lock the deployed shape of the gas collecting hood 5 after it is deployed, especially to resist the upward force of well water buoyancy on the central pipe 2 and prevent accidental contraction due to vibration, a multi-stage locking mechanism is provided between the central pipe 2 and the collar 3. This mechanism is used to mechanically lock the two when they slide relative to each other to a predetermined position.

[0064] Implementation Method 1 (Spring Pin-Slot Type): A series of annular slots or positioning holes with equal or unequal spacing are machined axially on the outer wall of the central tube 2. A corresponding elastic positioning component is installed on the inner wall of the collar 3. This component may include a steel ball or pin, a spring that protrudes inward, and an adjusting screw. When the central tube 2 is pulled upward (or pressed downward) to the gas collection hood 5 to reach the desired opening degree, the spring force pushes the steel ball or pin into the corresponding slot or positioning hole, achieving locking. To unlock, additional axial force must be applied to overcome the spring force, causing the pin to disengage from the slot.

[0065] Implementation Method Two (Friction Clamping Type): A friction locking clamp is integrated onto the collar 3. One end of the clamp is fixed, and the other end has an adjusting handle. The clamp is lined with a high-friction coefficient material (such as rubber or engineering plastic). Tightening the handle allows the clamp to grip the central tube 2, locking its position using friction. This method allows for stepless adjustment and locking.

[0066] Implementation Method 3 (Rack and Pinion Type): A rack with unidirectional helical teeth is fixed to the outer wall of the central tube 2. A pawl that can engage with the rack is hinged to the collar 3. The pawl maintains its engagement tendency with the rack through a torsion spring, allowing the central tube 2 to move unidirectionally in the unfolding direction and lock step by step. When moving in the reverse direction, the pawl needs to be manually opened to unlock it.

[0067] The technical advantage of this embodiment is that:

[0068] Precise adjustment and retention: The multi-stage locking design allows the operator to fine-tune the opening of the gas collection hood 5 to the optimal state (fully extended without overstretching) according to the actual well diameter, and retain this state by locking.

[0069] Anti-interference and stability: The locking mechanism can reliably maintain the deployed shape and resist the buoyancy caused by well water fluctuations, water flow impacts or other external forces that may cause unexpected contraction or shaking, thus ensuring the constant volume and sealing state of the gas collection chamber.

[0070] Ensuring sampling consistency: For scenarios requiring long-term sampling or comparable sampling at different time points, the locking mechanism ensures that the physical state (opening degree) of the device can be accurately reproduced each time gas is collected, thereby ensuring the temporal representativeness and data comparability of the collected gas samples.

[0071] Vibration and buoyancy simulation tests showed that after using an effective mechanical locking mechanism, the morphological stability and position retention capability of the gas collection hood 5 under simulated working conditions were improved by more than 30%.

[0072] Key load-bearing components of multi-stage locking mechanisms (such as spring pins, pawls, racks, or friction plates) should preferably be made of corrosion-resistant materials, such as stainless steel, anodized aluminum alloys, or engineering plastics (such as POM). This ensures that the mechanism maintains flexible operation and reliable locking performance even in humid, potentially corrosive environments underground, preventing jamming or failure due to corrosion. Accelerated aging and field tracking tests showed that locking mechanisms with corrosion-resistant designs maintained over 95% functionality after one year of use in typical field environments.

[0073] The above embodiments are merely exemplary embodiments of this application and are not intended to limit this application. The scope of protection of this application is defined by the claims. Those skilled in the art can make various modifications or equivalent substitutions to this application within its substance and scope of protection, and such modifications or equivalent substitutions should also be considered to fall within the scope of protection of this application.

Claims

1. A novel wellhead gas collection device, characterized in that, include: The fixing rod (1) serves as a support at the edge of the well; An deployable umbrella rib mechanism, the umbrella rib mechanism comprising: Central tube (2); The collar (3) is slidably sleeved on the outer wall of the central tube (2); The connecting rod (4) has multiple sets, which are arranged circumferentially around the central tube (2) to connect the central tube (2) and the collar (3). It also includes a gas collection hood (5), which covers the outside of the umbrella rib mechanism and whose edge is connected to the outer end of the connecting rod (4); The fixed rod (1) is fixedly connected to the collar (3), and the central tube (2) can move axially relative to the fixed rod (1) and the collar (3) to drive the connecting rod (4) to expand or contract the gas collection hood (5). The top of the central tube (2) is provided with an interface for connecting the gas collecting bottle (6), and its bottom is connected to a flexible guide hood (7). The lower edge of the flexible guide hood (7) is connected to the lower edge of the gas collecting hood (5), so that when the gas collecting hood (5) is unfolded, the bottom air inlet of the central tube (2) is always at the highest point of the gas collecting chamber formed by the gas collecting hood (5) and the flexible guide hood (7). The gas collecting bottle (6) is positioned upright, and its mouth is sealed by a sealing plug (11). An inlet pipe (12) and a drain pipe (13) are installed on the sealing plug (11). The inlet pipe (12) is connected to the interface at the top of the central tube (2) through a flexible connecting pipe (14), and one end of it extends into the gas collecting bottle (6) and is located at the upper part of the bottle body. One end of the drain pipe (13) extends into the gas collecting bottle (6) and is located at the bottom of the gas collecting bottle (6). The inlet pipe (12) and the drain pipe (13) are each independently equipped with a first control valve. It also includes a bracket (18) for fixing to the well, wherein the fixing rod (1) is detachably or fixedly installed on the bracket (18); The bracket (18) includes a triangular support foot for supporting the wellhead ground and a telescopic rod for adjusting the height.

2. The novel wellhead gas collection device according to claim 1, characterized in that, The gas collecting bottle (6) is connected upside down to the interface at the top of the central tube (2) via a quick-release connector (8) with the bottle opening facing downwards. The central tube (2), the quick-release connector (8), and the bottle opening of the gas collecting bottle (6) together form a channel for draining and collecting gas.

3. A novel wellhead gas collection device according to claim 2, characterized in that, The quick-release connector (8) or the central tube (2) is provided with a second control valve (9) for controlling the gas flow.

4. A novel wellhead gas collection device according to claim 3, characterized in that, The quick-release connector (8) has an O-ring on its mating surface.

5. A novel wellhead gas collection device according to claim 1, characterized in that, The lower edge of the gas collection hood (5) is fitted with an inflatable sealing ring (16).

6. A novel wellhead gas collection device according to claim 5, characterized in that, The inflatable sealing ring (16) is connected to an inflatable pipe (17), which extends to the wellhead and has a quick interface at its end for connecting to an external gas or liquid source.

7. A novel wellhead gas collection device according to claim 1, characterized in that, A multi-stage locking mechanism is provided between the central tube (2) and the collar (3) to lock the relative axial position of the central tube (2) and the collar (3) after the gas collection hood (5) is unfolded.

Images