A wellhead sealing and blowout prevention device for heavy oil thermal recovery

Abstract

The invention relates to the technical field of heavy oil thermal recovery, and discloses a wellhead sealing and blowout prevention device for heavy oil thermal recovery, including a polished rod, a packing box, emergency static sealing packing, rotary pumping static sealing packing and rotary pumping dynamic sealing packing , the packing box is slidably assembled on the polished rod, including the emergency static sealing chamber body, valve body, rotary pumping static sealing chamber body, dynamic sealing chamber body and dynamic sealing packing pressing body arranged in sequence from bottom to top. For the valve assembly and the rotary pumping valve assembly, the dynamic sealing packing press body is provided with a dynamic packing pressing assembly; the emergency static sealing packing is provided in the emergency static sealing chamber; the rotary pumping static sealing packing is provided in the rotary pumping static sealing chamber ; The rotary pumping dynamic sealing packing is set in the dynamic sealing chamber body and is compressed by the dynamic packing pressing component to realize sealing. The invention integrates wellhead blowout prevention, sealing, pumping transfer and emergency valve, and has the advantages of safety, reliability, convenient operation and low cost.

Description

technical field [0001] The invention relates to the technical field of thermal recovery of heavy oil, in particular to a wellhead sealing blowout prevention device for thermal recovery of heavy oil. Background technique [0002] Pumping units (kowtow machines) are widely used in oilfield production sites at home and abroad. The polished rod plays the role of transmitting power and sealing the wellhead in conjunction with the packing box in the oil extraction of the pumping unit. The heavy oil extraction and pumping operation also includes production cycles such as high temperature gas injection at the wellhead and self-blowing period of the well. [0003] Heavy oil is a kind of high-viscosity and high-density crude oil with complex components, generally containing asphaltenes and colloids. It is an important component of petroleum hydrocarbon energy. Although the viscosity of heavy oil is high, it is extremely sensitive to temperature. Part of the heavy oil thermal recovery...

AI Technical Summary

Problems solved by technology

[0005] In the extraction stage of the kowtow machine, after a period of dynamic operation, when the packings in the three sealed chambers are worn or aged and cannot meet the sealing requirements, new packings need to be replaced. The specific operations are: need to release the pressure and The power of the kowtow machine is used to forcibly lift the anti-blowout plunger of the polished rod to realize the sealing between the plug head at the bottom of the anti-blowout plunger and the tapered wedge of the packing box (but it is often not completely sealed), and then the three parts are quickly removed at high temperature. Take out the packing of the first sealed warehouse, and then replace the static sealed packing in the third-level warehouse by spinning until it is completely sealed, and then replace it in sequence in the order of the second-level warehouse and the second-level warehouse, and then loosen the third-level warehouse after the replacement. At the same time, the static sealing disc in the stage chamber loosens the polished rod anti-blowout plunger before pumping (in some wellheads, the packing may be replaced several times in a day), if the polished rod anti-blowout plunger is lifted, if the seal cannot be achieved, due to If the wellhead pressure is too high and the temperature is high, the packing cannot be replaced, and the packing needs to be completely relieved and cooled to replace the packing. The whole process is cumbersome and takes a long time, which seriously affects the extraction efficiency;

[0006] Due to the aging of graphite packing in the tertiary warehouse after high temperature, the packing is prone to carbonization to shattering. After the steam injection and braising well, the plug head and the tapered wedge will often be stuck and locked, and cannot be removed and cannot be entered normally. Production, which requires the staff to overhaul the wellhead at high temperature to separate the bolt head from the wedge cone mouth, and there is a safety hazard of prone to burns;

[0007] 2) The high-pressure glue-injection-type packing box adopts the dynamic operation seal of the first-level warehouse and the second-level warehouse, and a high-temperature glue-injection warehouse is added to seal the wellhead with high-pressure and high-temperature glue injection. Pumping and packing replacement operations, but depending on the conditions of each well, most of the high-pressure and high-temperature glue injection takes 3 hours to complete, and a small number of wellheads take 0.5 to 1 working day to complete, and most of them are in During the glue injection process, the polished rod will be pushed and bent, which has a certain impact on the sealing. In actual use, the packing seal operation cycle of the first-level warehouse and the second-level warehouse generally ranges from 24 to 300 hours (some wellheads may appear within a day. Replace the packing several times), the direct cost of replacing the packing and glue injection once is high, frequent packing replacement affects the extraction efficiency, and the cost is also greatly increased

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