Thermal production snubbing device

Abstract

The invention discloses a thermal production snubbing device, which comprises a christmas tree, a hot fluid pipe column, a top switching valve device and an anti-pollution back-pressure valve tool, wherein the anti-pollution back-pressure valve tool is arranged in a pit-shaft sleeve, the lower part of the anti-pollution back-pressure valve tool is provided with a perforated pipe column, and the top switching valve device is arranged on the pit-shaft sleeve; and the hot fluid pipe column is arranged on the lower part of the top switching valve device and can be inserted into the anti-pollutionback-pressure valve tool, and the christmas tree is arranged on the top of the top switching valve device. The thermal production snubbing device is free from blowout and well killing operations after a thick oil well is infused with hot fluid and is soaked, and avoids kill fluid from causing cold damages to layers infused with hot thick oil to play a role of protecting oil layers.

Description

technical field [0001] The invention relates to a thermal recovery snubbing device used for oil recovery of heavy oil wells in offshore oil fields. Background technique [0002] In the heavy oil wells of offshore oilfields, the method of injecting hot fluid (such as steam or hot water) is mainly used to increase the temperature of the heavy oil in the formation to reduce the viscosity of the heavy oil in the formation, change the flow capacity of the heavy oil in the formation, and achieve enhanced oil recovery. rate purposes. [0003] However, there are the following problems in the process of injecting thermal fluid stimulation: 1. After injecting thermal fluid into the thermal recovery well and basking in the well, the formation fluid pressure of the heavy oil layer injected with the thermal fluid is relatively high, and it takes a long time to discharge; For blowout and well killing operations, it is necessary to wait for the pressure of the formation fluid to drop befo...

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Problems solved by technology

[0003] However, there are the following problems in the process of injecting thermal fluid stimulation: 1. After injecting thermal fluid into the thermal recovery well and basking in the well, the formation fluid pressure of the heavy oil layer injected with the thermal fluid is relatively high, and it takes a long time to discharge; For blowout and well killing operations, it is necessary to wait for the pressure of the formation fluid to drop before pulling out the hot fluid injection pipe string; In other words, the killing fluid will cause a large amount of heat loss and cause cold damage (that is, recontamination of the heated heavy oil layer), which will seriously affect the thermal recovery effect of the heavy oil layer after injecting the hot fluid; 3. When pulling out the hot fluid injection string , the heavy oil formation still has relatively high fluid (crude oil, water) pressure, that is, there is a relatively high back pressure. This back pressure is an unsafe factor in the process of pulling out and injecting hot fluid pipe strings. Once there is a control error , there is a certain hidden danger of safety accidents

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