Pressing cap of oil storage packing box

Abstract

Provided is an oil storage packing box pressing cap. The device comprises a lower pressing cap, an oil storage chamber, a sealing gasket and an upper pressing cap, a center hole is formed in the center of the lower pressing cap, and the lower portion of the lower pressing cap is connected to the packing box in a threaded mode. The oil storage chamber is annular, the lower end of the oil storage chamber is mounted at the top edge of the lower pressing cap, an oil filling hole is formed in the middle side wall and used for mounting a grease filling nozzle, the inner circumferential surface of the upper part of the oil storage chamber protrudes outwards to form an annular step, and threads are formed on the outer circumferential surface; the edge of the sealing gasket is placed on the annular step of the oil storage chamber; the lower portion of the upper pressing cap is installed on the outer circumferential face of the oil storage chamber through internal threads. The device has the advantages that potential safety and environmental protection hazards are eliminated, the service life and the replacement period of the packing box sealing filler are prolonged, the labor intensity of workers is relieved, meanwhile, after the device is installed on the packing box, the overall strength is not changed, normal unloading work of a pumping unit can be completed, and the oil well production efficiency is improved.

Description

Technical Field

[0001] The invention belongs to the technical field of oil field development, and in particular relates to an oil storage packing box pressure cap. Background Art

[0002] In the exploitation of oilfield pumping wells, in order to seal the wellhead bare rod, it is necessary to fill the sealing packing in the wellhead packing box to seal the bare rod moving up and down in the packing box. With the development of oilfields, there are more and more high-water-content oil wells. During production, it is found that the packing box of high-water-content oil wells frequently leaks, causing serious environmental pollution. After the ordinary oil well sealing packing is filled and used for more than 20 days, it can still ensure that the wellhead packing box does not leak. However, after the high-water-content well sealing packing is filled and used for less than 5 days, the sealing packing will fail and leak. The reason is that the water content of the oil well production fluid is too high, the oil content in the production fluid is low, and the packing and the bare rod are not lubricated enough, resulting in faster wear of the packing and leakage of the wellhead packing box. At present, the method of applying butter to the wellhead to increase lubrication is mostly used on site, but it cannot effectively solve the above problems. The reason is that the amount of butter in the packing box is small, and the butter is quickly taken away when the bare rod on the pumping unit is running, so it cannot achieve a long-term lubrication effect. In addition, puncture leakage will cause serious environmental pollution. At the same time, frequent replacement of sealing packing will reduce the production efficiency of oil wells and increase the labor intensity of workers.

[0003] At present, the commonly used methods to solve the above problems include external auxiliary lubrication of the bare rod and internal auxiliary lubrication of the packing box. The external auxiliary lubrication method will affect various daily unloading operations, and the structure is relatively complex and the lubrication effect is general; the operation and maintenance are cumbersome, and to a certain extent it will destroy the strength of the packing box body at the wellhead of the pumping unit, so there is a safety hazard.

[0004] Chinese patent CN 201621391770.4 discloses a packing box; the outer side of the packing box body is opened with one or more lubricating devices installed to lubricate the packing box sealing filler. The problem of sealing filler lubrication is solved, but the device will reduce the strength of the packing box body. When adding a lubricating device, new oil and gas leakage risk points will be added, creating new safety and environmental hazards.

[0005] Chinese patent CN 202220507427.0 discloses an oil well packing box lubricator; it realizes lubrication of the polished rod and sealing packing by adding an external lubricating oil chamber to the polished rod. The patent lubricates the sealing packing and the polished rod to a certain extent, but it will affect the unloading work in various daily operations of the oil well. When unloading, it needs to be removed, which is relatively time-consuming and labor-intensive, thus affecting work efficiency. Summary of the invention

[0006] In order to solve the above problems, the object of the present invention is to provide an oil storage packing box pressure cap.

[0007] In order to achieve the above-mentioned purpose, the oil storage packing box pressure cap provided by the present invention includes a lower pressure cap, an oil storage chamber, a sealing gasket and an upper pressure cap; wherein, a center hole is formed at the center of the lower pressure cap, and the lower part is threadedly connected to the packing box; the oil storage chamber is annular, and the lower end is installed on the top edge of the lower pressure cap, and a refueling hole is formed on the middle side wall for installing a grease filling nozzle, and an annular step is formed on the upper inner circumferential surface protruding outward, and a thread is formed on the outer circumferential surface; the edge of the sealing gasket is placed on the annular step of the oil storage chamber; the lower part of the upper pressure cap is installed on the outer circumferential surface of the oil storage chamber through an internal thread.

[0008] The inner and outer diameters of the oil storage chamber are the same as those of the packing box, and the height is 80-150 mm.

[0009] The sealing gasket is made of sealing filler for packing box.

[0010] The oil storage packing box pressure cap provided by the present invention has the following beneficial effects: it eliminates the problem of packing leakage caused by frequent damage of the packing box sealing filler at the wellhead of high water-content oil wells due to dry grinding caused by lack of lubrication, eliminates safety and environmental protection hazards, extends the service life and replacement cycle of the packing box sealing filler, and reduces the labor intensity of the staff. At the same time, the overall strength of the packing box remains unchanged after the device is installed, and the normal unloading work of the oil pump can be completed, thereby improving the production efficiency of the oil well. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] Figure 1 A three-dimensional diagram of the oil storage packing box pressure cap structure provided by the present invention.

[0012] Figure 2 A three-dimensional diagram of the oil storage chamber in the oil storage packing box pressure cap and the lower pressure cap structure provided by the present invention.

[0013] Figure 3 A cross-sectional view of the oil storage chamber in the oil storage packing box pressure cap and the lower pressure cap structure provided by the present invention.

[0014] Figure 4 A three-dimensional diagram of the structure of the middle and upper pressure caps of the oil storage packing box pressure cap provided by the present invention.

[0015] Figure 5 A cross-sectional view of the oil storage packing box pressure cap structure provided by the present invention. DETAILED DESCRIPTION

[0016] The present invention is described in detail below with reference to the accompanying drawings and specific embodiments.

[0017] like Figure 1-Figure 5As shown, the oil storage packing box pressure cap provided by the present invention includes a lower pressure cap 1, an oil storage chamber 2, a sealing gasket 3 and an upper pressure cap 4; wherein, a center hole is formed at the center of the lower pressure cap 1, and the lower part is threadedly connected to the packing box; the oil storage chamber 2 is annular, and the lower end is installed on the top edge of the lower pressure cap 1, and a refueling hole 5 is formed on the middle side wall for installing a grease filling nozzle, and an annular step 6 is protruding outward on the upper inner circumferential surface, and a thread is formed on the outer circumferential surface; the edge of the sealing gasket 3 is placed on the annular step 6 of the oil storage chamber 2; the lower part of the upper pressure cap 4 is installed on the outer circumferential surface of the oil storage chamber 2 through an internal thread.

[0018] The inner and outer diameters of the oil storage chamber 2 are the same as those of the packing box, and the height is 80-150 mm.

[0019] The sealing gasket 3 is made of sealing filler for packing box.

[0020] The installation and use method of the oil storage packing box pressure cap provided by the present invention is described as follows:

[0021] During installation, tighten and fix the lower pressure cap 1 on the pressure cap of the oil storage packing box on the packing box, install the sealing gasket 3 on the annular step 6 of the oil storage chamber 2, tighten the upper pressure cap 4, and then fill the oil storage chamber 2 with butter through the butter filling nozzle on the grease gun through the filling hole 5. After the butter is filled, the pumping unit can be started for normal production. During the production process, butter can be added through the filling hole 5 at any time according to the situation.

[0022] In addition, the pressing cap 1 can adopt the original pressing cap of the packing box of the wellhead of the oil pumping unit, so that the original strength and sealing performance of the packing box body can be guaranteed. The oil storage chamber 2 is an external chamber of the original lower pressure cap of the packing box at the wellhead of the pumping unit. It will not destroy the structure of the packing box body, will not create new potential leakage points, and its size and strength are consistent with the packing box, and the overall strength can be guaranteed by cooperating with the upper pressure cap 4; the sealing gasket 3 is installed on the annular step 6 of the oil storage chamber 2. Due to the supporting effect of the annular step 6, the sealing gasket 3 will not slide into the oil storage chamber 2, and it plays a sealing role on the top of the oil storage chamber 2, ensuring that the grease will not be taken away with the up and down movement of the bare rod, thereby producing a continuous lubrication effect; in addition, the sealing gasket 3 is made of the same material as the sealing filler used in the packing box, and the universality of the sealing filler facilitates the installation operation and reduces the operating cost; the function of the upper pressure cap 4 is, on the one hand, to compress and seal the sealing gasket 3, and on the other hand, because it is designed to be exactly the same as the structure of the original upper pressure cap of the packing box of the pumping unit, it cooperates with the oil storage chamber 2 and the lower pressure cap 1, so that the overall strength is not reduced, so it can meet the requirements of normal operations such as unloading.

Claims

1. An oil storage packing box pressure cap, Features: The oil storage packing box pressure cap comprises a lower pressure cap (1), an oil storage chamber (2), a sealing gasket (3) and an upper pressure cap (4); wherein a center hole is formed at the center of the lower pressure cap (1), and the lower part is threadedly connected to the packing box; the oil storage chamber (2) is annular, and the lower end is installed on the top edge of the lower pressure cap (1); a refueling hole (5) is formed on the middle side wall for installing a grease filling nozzle; an annular step (6) is formed on the upper inner circumferential surface protruding outward, and a thread is formed on the outer circumferential surface; the edge of the sealing gasket (3) is placed on the annular step (6) of the oil storage chamber (2); the lower part of the upper pressure cap (4) is installed on the outer circumferential surface of the oil storage chamber (2) through an internal thread.

2. The oil storage packing box pressure cap according to claim 1, Features: The inner and outer diameters of the oil storage chamber (2) are the same as those of the packing box, and the height is 80-150 mm.

3. The oil storage packing box pressure cap according to claim 1, Features: The sealing pad (3) is made of sealing filler for packing box.

Images