Device and technological method for pulling lower oil tube

Abstract

The invention discloses a device and a technological method for pulling a lower oil tube. The device comprises a large cross, a hanger, a hanger plug, a double ram type preventer and a sealing piece. The large cross comprises a first channel, a second channel, a third channel and a fourth channel, wherein the first channel is connected with a well mouth flange in a sealing mode, and the second channel is connected with the double ram type preventer in a sealing mode. A hanger seat is arranged at the position of the second channel, an open flow pipeline is arranged on the third channel and / or the fourth channel, and a first valve is arranged on the open flow pipeline. A liquid flow channel is formed between the hanger and the large cross, the hanger is provided with a first matching part and a second matching part opposite to the first matching part, the first matching part is matched with the hanger seat, and the second matching part is used for fixing the oil tube. The lower end of the hanger plug is fixed to the hanger in a sealing mode. The double ram type preventer is connected with a containing seat in a sealing mode. The sealing piece is arranged in the containing seat. The device and the technological method for pulling the lower oil tube are suitable for non-well killing operation, high in operation efficiency and low in cost.

Description

technical field [0001] The invention relates to the technical field of oil field snubbing operation, in particular to equipment and a process method for tripping and tripping oil pipes. Background technique [0002] As the oilfield develops in the middle and later stages, the reservoir pressure decreases, and the number of low-pressure wells gradually increases. The low-pressure well mainly means that the wellhead shut-in pressure is not greater than 1 MPa, the gas-liquid ratio is not greater than 100, the fluid temperature is not higher than 80 degrees Celsius, the hydrogen sulfide content is not higher than 15 mg / m3, and the formation pressure coefficient is less than 0.7 oil wells. [0003] When the tubing operation is performed on the low-pressure well, the well must be killed first by injecting well killing fluid into the well, especially for wells with serious leakage, multiple well killing methods must be adopted. During the killing operation, the killing fluid inje...

AI Technical Summary

Problems solved by technology

When the forced lifting mechanism is operated, there are defects of low efficiency and high cost: generally, when operating through the forced lifting mechanism, due to its huge equipment, usually 5 meters high, it is necessary to be equipped with a special working platform; Due to the huge equipment, the forced lifting mechanism is also slow in installation and transportation, its lifting speed is slow during operation, it is slow to connect and unload pipe strings from the work platform, and the process of unplugged tools or special tools in the underground is slow, so generally The single well operation time is more than 10 days, and the single well operation cost is about 170,000

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