a dispensing column

Abstract

The invention relates to a dispensing column. The dispensing string includes an outer pipe and an inner pipe located inside the outer pipe. An annular cavity for injecting water into the upper formation is formed between the inner pipe and the outer pipe. The outer pipe is provided with a bottom water injection channel. There is a sealing structure that separates the bottom water injection channel from the ring cavity. The outer pipe is equipped with a movable valve core for controlling the opening and closing of the bottom water injection channel at the bottom water injection channel. The movable spool is driven to control the driving member for opening the bottom water injection channel, and the inner tube has an internal water injection channel for communicating the inner cavity of the inner tube with the bottom water injection channel when the bottom water injection channel is opened. The distributing pipe string controls the on-off of the water injection channel at the bottom of the outer pipe through the driving part provided under the inner pipe, which avoids the use of killing fluid for well killing operations and greatly reduces the construction cost.

Description

technical field [0001] The invention relates to the field of oil and gas field exploitation, in particular to a split injection pipe string. Background technique [0002] As the oilfield enters the later stage of development, the water injection pressure continues to increase. In order to ensure safe production, it is necessary to release the pressure or kill the well before operating the pipe string. The use of pressure relief means increases the construction period, wastes injection energy, and easily damages the casing due to the large change in pressure difference. On the one hand, the use of high-density well killing fluid increases the operation and construction costs. On the other hand, well killing is easy to cause pollution to the formation, and the formation is crushed to death, resulting in a sharp drop in the permeability of the reservoir near the wellbore, and the oil, gas and water in the formation cannot flow into the wellbore. . [0003] The utility model p...

AI Technical Summary

Problems solved by technology

[0004] The purpose of the present invention is to provide a separate injection pipe string to solve the technical problems in the prior art that the pipe string cannot be tripped without snubbing and the construction cost is high

Images