An oil well sampling valve

Abstract

This utility model relates to an oil well sampling valve, belonging to the field of oil well sampling valves. The sampling valve includes a valve body, a valve cover, and a valve stem assembly. The valve body has a three-way structure, including an oil inlet channel, an oil outlet channel, and a connecting end coaxial with the oil inlet channel and fixedly connected to the valve cover. A valve seat is provided at the junction of the valve body's inlet end and its inner cavity. The valve stem assembly includes a rod body. One end of the rod body facing the valve seat has a valve core for opening and closing the oil inlet channel. The other end of the rod body facing away from the valve seat has a connecting part for axial reciprocating movement with the valve cover. The valve stem body rotatably engages with the valve cover. A plug rod is fixedly installed on the end face of the valve core facing the inlet. When the sampling valve is closed, the top of the plug rod extends along the inner pipe wall extension line of the wellhead flow path via a welded short section. This device solves the problem of freezing blockage in the "blind section" and provides good sealing during sampling.

Description

Technical Field

[0001] This utility model relates to an oil well sampling valve, belonging to the field of oil well sampling valves. Background Technology

[0002] During the production process, oil wells need to regularly sample, test, and analyze the produced fluids to understand their properties, water content changes, and yield, ensuring that the crude oil quality meets standards. Based on the test results, production measures can be adjusted in a timely manner to improve the oil well's recovery rate and economic benefits.

[0003] A sampling valve is a common device used in oil well production to collect produced fluids. It is installed on a welded short section of the horizontal pipeline flowing through the wellhead. The sampling valve consists of a valve body, valve cover, valve stem, and valve core. The valve body has a three-way structure, including an oil passage fixedly connected to the inlet welded short section, an oil outlet passage, and a connecting end coaxial with the inlet passage and fixedly connected to the valve cover. A valve seat, which seals with the valve core, is located on the side of the valve body near the welded short section. The valve core is located on the side of the valve stem near the welded short section, and the valve stem rotates with the valve cover. During operation, the valve stem moves within the valve body to clear the sampling port, allowing the produced fluid from the wellhead horizontal pipeline to flow through the valve body cavity and into the sampling port, completing the sampling. When the valve core returns to its original position, the produced fluid will no longer flow into the valve body cavity.

[0004] Crude oil often contains high levels of wax and gum, resulting in a high pour point; some even solidify at room temperature. This leads to the following problems with sampling valves: First, most field sampling valves are needle-type gate valves with orifice diameters of only a few millimeters, making them easily clogged by impurities and wax blocks in the produced fluid, preventing sample extraction. Second, in winter and low-temperature environments, the "blind section" between the sampling valve core and the wellhead flow, coupled with the freezing of crude oil at low temperatures, easily causes the stagnant produced fluid in this "blind section" to freeze and become blocked, preventing the extraction of samples. Third, oil wells are typically formed in the field, making them susceptible to crude oil theft.

[0005] Chinese utility model patent CN203239340U discloses a needle-type antifreeze sampling valve, including a valve body and a valve core. The valve core is tightly fitted to the valve body and is axially movable within an axially extending inner cavity of the valve body. One end of the inner cavity is connected to an oil inlet connected to an oil pipeline. The end of the valve core facing the oil inlet can extend axially out of the oil inlet, and the other end of the valve core passes through a gland and extends out of the valve body. Although this sampling valve solves the freezing blockage problem of the "blind section" by extending the valve core out of the oil inlet and tightly fitting it with the valve body, the tight fit between the valve core and the valve body is a sliding seal. Impurities in the crude oil can easily cause wear on the valve core or the inner cavity of the valve body, resulting in a reduced sealing effect. Furthermore, when the valve core is closed, it extends out of the oil inlet and remains in the horizontal pipeline of the wellhead, reducing the pipeline flow area, altering the flow pattern of the crude oil, and consequently affecting the accuracy of other metering equipment at the wellhead. Utility Model Content

[0006] The purpose of this invention is to provide an oil well sampling valve to solve the problems of sampling difficulties, reduced sealing effect, and reduced crude oil flow rate in the prior art when preventing freezing and blockage of the "blind section".

[0007] To achieve the above objectives, the technical solution of this utility model is as follows:

[0008] An oil well sampling valve includes a valve body, a valve cover, and a valve stem assembly. The valve body has a three-way structure, including an oil inlet channel and an oil outlet channel. The valve body also includes a connecting end coaxial with the oil inlet channel and fixedly connected to the valve cover. A valve seat is provided at the junction of the inlet end of the valve body and its inner cavity. The valve stem assembly includes a rod body. A valve core for opening and closing the oil inlet channel is provided at one end of the rod body facing the valve seat. A junction for axial reciprocating movement with the valve cover is provided on the rod body facing away from the valve seat. The valve stem body and the valve cover are rotatably engaged. A plug rod is fixedly installed on the end face of the valve core facing the inlet. When the sampling valve is closed, the top of the plug rod extends along the inner pipe wall extension line of the wellhead flow through a welded short section.

[0009] This invention relates to an improved oil well sampling valve. The valve's opening and closing is achieved through a seated engagement between the valve body and the valve core at the end of the valve stem. This seated engagement ensures a seal when the valve is closed. The rotational engagement between the valve stem assembly and the valve cover ensures a seal when the valve is open. A rod is located near the valve seat at one end of the valve core, passing through a welded short section. In winter and low-temperature environments, crude oil solidifies around the rod. When the valve core opens the sampling valve, the rod clears the sampling channel for the oil well sample, solving the freezing blockage problem caused by stagnant produced fluid in the "dead end" section. Furthermore, the rod extends through the welded short section to the inner pipe wall extension line of the wellhead flow path, preventing the rod from freezing inside the pipe and affecting sampling, and ensuring that the rod does not affect the flow rate of crude oil in the well when the sampling channel is closed.

[0010] Preferably, the diameter of the insertion rod is smaller than the inner diameter of the welding section and the oil inlet channel.

[0011] Preferably, the insertion rod is a plunger or a drill bit. A plunger facilitates the cleaning of impurities in the sampling channel when it is closed, ensuring smooth sampling. It also reduces the contact area between the end of the insertion rod and the crude oil in the wellhead process, further minimizing its impact on the crude oil flow velocity in the wellhead process.

[0012] Preferably, the insert rod and the valve stem assembly are coaxially arranged.

[0013] Preferably, a sealing gasket is provided on the end face of the valve core near the valve seat of the valve body. The valve seat and valve core setting seal can prevent crude oil leakage when the oil intake channel is closed. By providing a sealing gasket on the end face of the valve core, the sealing effect when the oil intake channel is closed can be further improved.

[0014] Preferably, the stem of the valve stem assembly is threaded to the valve cover, the joint between the stem and the valve cover is an external thread, and the inner cavity of the valve cover is provided with an internal thread for the stem to reciprocate along the axial direction of the valve cover.

[0015] Preferably, the valve cover has a limiting end on the side of its internal thread away from the connecting end, which limits the movement of the valve stem assembly when the sampling valve is opened. Further, the limiting end is provided with a sealing element.

[0016] Preferably, when the sampling valve is closed, the valve stem assembly has a seal between the valve body outlet end and the connecting end. The valve stem rotates with the valve cover, providing a certain sealing effect when the sampling valve is opened. Further adding a seal to the valve stem can better prevent crude oil sample from flowing into the rotating structure of the valve cover, thus improving the sealing effect.

[0017] Preferably, the sampling valve includes a tamper-evident wrench, and the valve cover has a receiving cavity for inserting the tamper-evident wrench at the end away from the connecting end. The valve stem assembly has a tamper-evident head at the end away from the valve body and valve seat that mates with the tamper-evident wrench. The irregular protrusions and grooves can transmit torque, facilitating the reciprocating rotation of the valve stem along the valve cover axially using the tamper-evident wrench. The tamper-evident head of the valve stem works in conjunction with the tamper-evident wrench, facilitating daily opening and closing while also serving a tamper-evident function.

[0018] Preferably, when the sampling valve is closed, the anti-theft head is located in the valve cover receiving cavity. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the oil well sampling valve in the closed state according to Embodiment 1 of this utility model;

[0020] Figure 2 This is a schematic diagram of the valve body in the oil well sampling valve of Embodiment 1 of this utility model;

[0021] Figure 3 This is a schematic diagram of the valve stem assembly and insert rod in the oil well sampling valve of Embodiment 1 of this utility model;

[0022] Figure 4 This is a schematic diagram of the anti-theft wrench in the oil well sampling valve of Embodiment 1 of this utility model;

[0023] Figure 5 This is a schematic diagram of the valve cover in the oil well sampling valve of Embodiment 1 of this utility model;

[0024] Figure 6 This is a schematic diagram of the oil well sampling valve in the working state according to Embodiment 1 of this utility model;

[0025] Among them, 1-Wellhead flow, 2-Welded short section, 3-Valve body, 4-Sealing gasket, 5-Sealing ring, 6-Valve cover, 7-External thread, 8-Sealing ring, 9-Anti-theft head, 10-Anti-theft wrench, 101-Groove, 102-Handle, 11-Insertion rod, 12-Oil outlet channel, 13-Valve stem assembly, 31-Internal thread, 32-Valve seat, 33-External thread, 34-Valve body cavity, 35-Oil inlet channel, 41-Valve core, 51-Secondary valve core, 61-Internal thread, 62-Internal thread, 63-Receiving cavity, 64-Reduction diameter limiting part. Detailed Implementation

[0026] While existing oil well sampling valves have solved the problem of freezing blockage in the "blind section," they have introduced new issues: poor sealing of the sampling device during sampling affects the sampling effect, and the flow rate of crude oil in the well is affected when the sampling valve is closed. This invention solves the freezing blockage problem in the "blind section" by installing a rod on the valve core near the valve body seat. Furthermore, when the sampling channel is closed, the end face of the rod extends through a welded short section to the inner wall extension line of the wellhead flow path, ensuring the flow rate of crude oil in the well while solving the freezing blockage problem. Simultaneously, the seated cooperation between the valve core and valve body, and the rotating cooperation between the valve stem assembly and valve cover, further ensure good sealing performance in both the closed and operating states of the sampling valve.

[0027] The technical solution of this utility model will be further described below with reference to specific embodiments.

[0028] The specific embodiments of the oil well sampling valve of this utility model are as follows:

[0029] Example 1

[0030] The oil well sampling valve in this embodiment, such as Figure 1 As shown, it includes valve body 3, valve cover 6, and valve stem assembly 13. Valve body 3 is a three-way structure (e.g., Figure 2 As shown), it includes an oil inlet channel 35, an oil outlet channel 12, and a connecting end coaxial with the oil inlet channel and fixedly connected to the valve cover 6. The inlet end of the valve body 3 is provided with an internal thread 31. The inlet end of the valve body 3 is threadedly connected to the welding short section 2 on the wellhead flow 1. The junction of the inlet end of the valve body 3 and its inner cavity 34 is provided with a valve seat 32. The connecting end of the valve body 3 is provided with an external thread 33 adapted to the inner cavity of the valve cover 6.

[0031] Valve stem assembly 13 Figure 3 As shown, the device includes a rod body. One end of the rod facing the valve seat 32 has a valve core 41 for opening and closing the oil inlet channel. The rod facing away from the valve seat 32 has an external thread 7 for axial reciprocating movement with the valve cover 6. The inner cavity of the valve cover 6 has an internal thread 62 that mates with the external thread 7 of the valve stem assembly 13. A plug rod 11 is fixedly installed on the end face of the valve core 41 facing the inlet. The plug rod 11 can be a cylinder, and its diameter is smaller than the inner diameter of the welded short section 2 and the oil inlet channel 35. When the sampling valve is closed, the top of the plug rod 11 extends through the welded short section 2 to the extension line of the inner pipe wall of the wellhead flow path 1. In other embodiments, if the blockage in the "blind section" is relatively hard, it can also be a pin or drill bit, as long as it is easy to advance and retreat. To better seal the sampling valve, a sealing gasket 4 can be provided on the end face of the valve core 41 near the valve seat 32. The sealing gasket 4 and the valve core 41 are rotated and pressed together by the external thread 7 of the valve stem assembly 13 to achieve a sealing effect.

[0032] The valve stem assembly 13 has an anti-theft head 9 at the end furthest from the inlet of the valve body 3, which is adapted to the groove of the anti-theft wrench 10. The anti-theft head 9 is an irregular protrusion, and it is located in the inner cavity of the valve cover 6 when the sampling channel is closed. The anti-theft wrench 10 includes a handle 102 and a groove 101 that mates with the protrusion of the anti-theft head 9 (e.g., ...). Figure 4 (As shown). The anti-theft head 9 of the valve stem assembly 13 is used in conjunction with the anti-theft wrench 10 to facilitate daily opening and closing and to serve as an anti-theft measure. In other embodiments, the front end of the anti-theft wrench may be a protrusion 10, and the end of the valve stem assembly 13 away from the inlet end of the valve body 3 may be a groove that fits therein.

[0033] The inner cavity of the valve cover 6 and the valve body 3 is provided with an internal thread 61. On the side of the internal thread 61 away from the connection end, there is a reduced-diameter limiting part 64 that limits the backward movement of the valve stem assembly 13 when the sampling valve is opened. A sealing ring 8 is provided in the middle of the reduced-diameter limiting part 64. On the side of the inner cavity of the valve cover 6 away from the connection end, there is a receiving cavity 63 for inserting an anti-theft wrench 10. The diameter of the anti-theft wrench 10 is smaller than the inner diameter of the receiving cavity 63 (e.g., ...). Figure 5 (As shown).

[0034] Furthermore, the anti-theft head 9 can be triangular or pentagonal.

[0035] Furthermore, to further improve the sealing effect of the sampling valve, when the sampling valve is in the closed state, the external thread 7 of the valve stem assembly 13 faces the inner cavity of the valve body 3, which serves to isolate the inner cavity sealing ring 5 of the valve body 3, preventing oil and gas impurities from entering the threaded joint between the valve stem assembly 13 and the valve cover. In other embodiments, the sealing ring 5 can be disposed on the valve stem assembly 13 via a secondary valve core 51.

[0036] The closed state of the oil well sampling valve is as follows: Figure 1 As shown, the insertion rod 11 passes through the welded short section 2 and extends to the inner pipe wall extension line of the wellhead process 1. The valve core 41 is seated on the valve seat 32 inside the valve body 3, thereby closing the sampling valve.

[0037] The working status of the oil well sampling valve is as follows Figure 6 As shown, during operation, the welding section 2 is horizontally welded and installed on the wellhead flow path 1 of the oil well. The valve body 3 of the oil well sampling valve is threadedly connected to the welding section 2 and installed on the wellhead flow path 1. During sampling, the anti-theft wrench 10 is inserted into the receiving cavity 63 of the valve cover 6, aligning the groove of the wrench with the anti-theft head 9 of the valve stem assembly 13 and locking it in place. The handle 102 of the anti-theft wrench is rotated counterclockwise, causing the valve stem assembly 13 and the insertion rod 11 to slowly move backward, opening the sampling valve, clearing the sampling channel, and realizing sampling.

[0038] After the oil well sampling operation is completed, rotate the anti-theft wrench handle 102 clockwise to move the valve stem assembly 13 and the insert rod 11 forward. When the valve core 41 contacts the valve seat 32, rotate the anti-theft wrench handle 102 to press the external thread 7 of the valve stem, so that the rod of the valve stem assembly 13 presses against the valve core to achieve setting and seal, thus closing the oil well sampling valve. Remove the anti-theft wrench 10. At this time, the anti-theft head 9 of the valve stem assembly 13 is completely hidden in the receiving cavity 63 of the valve body 3, which plays a role in security and anti-theft.

[0039] When the low temperature causes crude oil to solidify or wax blocks to clog the "blind section" of the welded sub 2, since the insertion rod 11 passes through the welded sub 2 and extends to the inner wall extension line of the wellhead process 1, a sampling channel for the flow of produced fluid will still be reserved. The anti-theft wrench handle 102 drives the valve stem assembly 13 and the insertion rod 11 to move slowly backward. The produced fluid will flow into the oil inlet channel 35 of the valve body 3 through the channel cleared by the insertion rod 11, flow through the inner cavity of the valve body 3, and finally flow out from the oil outlet channel 12 of the valve body 3, completing the oil well sampling operation.

[0040] When the well sampling valve needs inspection and maintenance, first close the control valves on both sides of the welded short section at the wellhead (Wellhead Flow 1), and release pressure and vent. Then, remove the valve body 3 and valve cover 6 in sequence. From the valve cover 6, remove the valve stem assembly 13, valve core 41, and insert rod 11. Inspect and clean each component, checking its internal and external appearance and sealing. After inspection and cleaning, reinstall each component in sequence, then install the well sampling valve on the well. Close the vent, open the control valves on both sides of the welded short section, and resume well production.

Claims

1. An oil well sampling valve comprising a valve body, a valve cover, a valve stem assembly, the valve body is a three-way structure, comprising an oil inlet channel and an oil outlet channel, characterized in that, The valve body also includes a connecting end coaxial with the oil inlet channel and fixedly connected to the valve cover. The valve body has a valve seat at the junction of its inlet end and its inner cavity. The valve stem assembly includes a stem body. The end of the stem body facing the valve seat of the valve body has a valve core for opening and closing the oil inlet channel. The stem body facing away from the valve seat has a junction for engaging with the valve cover in an axial reciprocating motion. The valve stem body and the valve cover are rotatably engaged. A plug is fixedly installed on the end face of the valve core facing the inlet. When the sampling valve is closed, the top of the plug extends along the inner pipe wall extension line of the wellhead flow through a welded short section.

2. The oil well sampling valve of claim 1, wherein, The diameter of the insertion rod is smaller than the inner diameter of the welding section and the oil inlet channel.

3. The oil well sampling valve of claim 2, wherein, The insertion rod is a pin or a drill bit.

4. The oil well sampling valve of claim 2, wherein, The insert rod and the valve stem assembly are coaxially arranged.

5. The oil well sampling valve of claim 1, wherein, A sealing gasket is provided on the end face of the valve core near the valve body and valve seat.

6. The oil well sampling valve according to claim 1, characterized in that, The stem of the valve stem assembly is threadedly connected to the valve cover. The joint between the stem and the valve cover is an external thread, and the inner cavity of the valve cover is provided with an internal thread for the stem to reciprocate along the axial direction of the valve cover.

7. The oil well sampling valve according to claim 6, characterized in that, The valve cover has a limiting end on the side of its internal thread away from the connection end, which limits the movement of the valve stem assembly when the sampling valve is opened.

8. The oil well sampling valve according to any one of claims 1-7, characterized in that, When the sampling valve is closed, the valve stem assembly has a seal between the valve body outlet end and the connection end.

9. The oil well sampling valve according to any one of claims 1-7, characterized in that, The sampling valve includes an anti-theft wrench, and the valve cover has a receiving cavity for inserting the anti-theft wrench at one end away from the connecting end. The valve stem assembly has an anti-theft head at one end away from the valve body and valve seat that mates with the anti-theft wrench.

10. The oil well sampling valve according to claim 9, characterized in that, With the sampling valve closed, the anti-theft head is located in the valve cover cavity.

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