CN-117266778-B - Pumping unit polish rod wellhead sealing method and pumping unit sealing filler

Abstract

The invention relates to a method for sealing a polished rod wellhead of an oil pumping unit and sealing filler of the oil pumping unit, and belongs to the technical field of oil extraction engineering of oil fields. The wellhead sealing method of the polish rod of the pumping unit comprises the following steps of sleeving an annular gasket on the polish rod, putting the bottom of a cavity of a wellhead packing box, alternately putting a rubber strip and a semisolid lubricant in the cavity of the packing box until the packing box is fully filled, sleeving the annular gasket on the polish rod, mounting a gram and a packing pressing cap, tightening, and putting the rubber strip around the polish rod and fully paving a layer in the cavity of the packing box when the rubber strip is put. The polish rod sealing method of the oil pumping machine thoroughly solves the problem of difficult adding and taking when the packing filler is replaced, reduces the labor intensity of post workers, is particularly suitable for oil wells with non-centered polish rods on site, has good sealing effect, can effectively treat the phenomenon of packing leakage, reduces abrasion, prolongs the service cycle of the packing, and achieves the purposes of cost reduction, efficiency enhancement, energy conservation and environmental protection.

Inventors

• LI YONGLI
• WANG ZHENHUA
• DONG KUIFENG
• LI XIAOQI
• GENG FENG
• JIANG YONGRONG

Assignees

• 中国石油化工股份有限公司

Dates

Publication Date

20260508

Application Date

20220615

Claims (4)

1. 1. A method for sealing a wellhead of a polished rod of an oil pumping machine comprises the steps of taking an annular gasket, putting the annular gasket on the polished rod, putting the bottom of a wellhead packing box cavity, then alternately putting rubber strips and semi-solid lubricant in the packing box cavity until packing sealing boxes are filled, taking the annular gasket, putting the annular gasket on the polished rod, well installing a gram and packing press caps, tightening, putting the rubber strips around the polished rod, fully paving a layer of rubber strips in the packing box cavity, wherein the mass ratio of the rubber strips to the semi-solid lubricant is 40-65:22.5-60, carrying out layer-by-layer compaction treatment on the put rubber strips and semi-solid lubricant in the process of alternately putting the rubber strips, wherein the rubber strips are made of waste rubber belts and/or waste packing recovered in an oil field, the semi-solid lubricant consists of 2.5 parts by weight of molybdenum disulfide lithium-based lubricating grease, 5-15 parts by weight of graphite powder, 10-20 parts by weight by the graphite powder, 5-10 parts by the weight by the organic bentonite, putting the annular gasket on the polished rod, and the packing press caps in sequence, and setting the average particle size of the graphite powder to be 26-30 mu m by the average particle size of the average of 26 mu m, and the average particle size of the rubber powder is 50 mu m by pressing the average particle size of the rubber caps on the polished rod.
2. 2. The method for sealing a polished rod wellhead of a pumping unit according to claim 1, wherein the annular gasket is an annular dovetail type plug gasket.
3. 3. The polished rod wellhead sealing method of pumping unit of claim 1, wherein the semisolid lubricant is uniformly spread on the rubber strip layer when the semisolid lubricant is put in.
4. 4. The sealing filler for the oil pumping unit is characterized by comprising 2.5-5 parts by weight of molybdenum disulfide lithium-based lubricating grease, 5-15 parts by weight of graphite powder, 10-20 parts by weight of lead powder and 5-10 parts by weight of organic bentonite, wherein the average particle size of the graphite powder is 15-20 mu m, the average particle size of the lead powder is 26-30 mu m, the average particle size of the organic bentonite is 30-50 mu m, and the diameter of the rubber strip is 5-7 mm.

Description

Pumping unit polish rod wellhead sealing method and pumping unit sealing filler Technical Field The invention relates to a method for sealing a polished rod wellhead of an oil pumping unit and sealing filler of the oil pumping unit, and belongs to the technical field of oil extraction engineering of oil fields. Background The main production equipment in oil extraction production is rod pumping equipment, and the polish rod sealing device at the wellhead of the oil well is an indispensable device for the rod pumping equipment, and the performance of the polish rod sealing device directly influences the working quality and the environmental quality of the ground pumping unit and the underground equipment thereof. The packing box is used as the sealing device of the polish rod of the oil pumping unit, and is filled with sealing filler capable of enabling the polish rod to pass through, so that an annular space between the oil pipe and the polish rod can be sealed. However, in the oil extraction production field, factors such as foundation subsidence, operation horsehead turning, oil pumping unit installation deviation, well structure and wellhead deformation easily cause the polish rod to be not centered, so that the O-shaped rubber sealing ring is not easy to take when being replaced, and the service life is greatly shortened. Especially for the oil well that is in later stage exploitation, the polished rod corrodes seriously, "O" rubber seal gets the degree of difficulty and further increases to sealed effect is poor, often appears running, emit, leak the phenomenon, causes well head equipment pollution, brings inconvenience for safe production, has increased post workman's intensity of labour. Meanwhile, the replaced old packing is discarded everywhere and cannot be recycled, and the phenomenon of recycling does not exist in the old belt replaced by the pumping unit, and environmental pollution is caused by the phenomenon of different degrees. In the prior art, china patent document CN 106246128A discloses a pumping unit wellhead polish rod sealing injection type filler, which is prepared by uniformly mixing, heating and stirring 20-40 parts of polytetrafluoroethylene, 10-35 parts of aramid fiber, 10-35 parts of molybdenum disulfide, 8-30 parts of silicone oil, 5-20 parts of tungsten disulfide, 1-10 parts of silicone grease and 1-10 parts of paraffin wax, wherein the stirring temperature is controlled at 105-195 ℃ and the stirring time is 1.5-15 h. When the packing is adopted for sealing, the packing can be conveniently and rapidly filled into the sealing cavity through the material injection port by using the material injection tool in a non-stop state, and packing replacement is not required to be frequently stopped, so that the labor intensity is reduced, but the packing is only suitable for sealing equipment with the material injection port, and is not suitable for traditional sealing equipment. Disclosure of Invention The invention aims to provide a method for sealing a polished rod wellhead of an oil pumping unit without changing a sealing device structure, which can thoroughly solve the problem of difficult adding and taking when packing filler is replaced. The invention also provides a sealing filler of the pumping unit. In order to achieve the above purpose, the technical scheme adopted by the pumping unit polish rod wellhead sealing method of the invention is as follows: A method for sealing the wellhead of polished rod of pumping unit includes such steps as sleeving the annular gasket on polished rod, putting it in the bottom of cavity of packing box, alternatively putting rubber strip and semi-solid lubricant in the cavity of packing box until packing box is full, sleeving it on polished rod, loading gram and packing cap, and tightening. The method for sealing the wellhead of the polish rod of the oil pumping unit breaks through the original packing sealing mode, thoroughly solves the problem of difficult adding and taking when packing filler is replaced, reduces the labor intensity of post workers, and is simple and convenient in operation process especially for an oil well with a polish rod not centered on site. In addition, the sealing method has good sealing effect, can effectively treat the packing leakage phenomenon, can reduce abrasion, prolongs the service cycle of the packing, and achieves the purposes of cost reduction, efficiency enhancement, energy conservation and environmental protection. Further, the annular gasket is an annular dovetail type plug gasket. Furthermore, the annular dovetail type plug gasket is formed by connecting more than two fan-shaped annular plug pieces end to end, wherein the head end of each fan-shaped annular plug piece is a dovetail type plug, and the tail end of each fan-shaped annular plug piece is a dovetail type slot matched with the dovetail type plug at the head end. The width of the annular gasket is matched with the annulus between the polish rod a