Method for putting in and taking out coiled tubing being used as production tubing string

Abstract

The invention discloses a method for putting in and taking out a coiled tubing being used as a production tubing string. The method for putting in the coiled tubing being used as a production tubing string comprises steps of mounting a well head blowout preventer system, an injection head and the coiled tubing above a tubing head four-way joint and a main valve, mounting a tool string to the lower end of the coiled tubing, and putting into a designed depth; cutting the coiled tubing off by a shear ram of a first blowout preventer; sequentially mounting a hanging connector and a tubing hanger to the upper end of the cut low-half coiled tubing, stretching the cut up-half coiled tubing out of a blowout preventing tubing, and connecting the cut up-half coiled tubing with a hydraulic retractable feeding/recycling tool; putting the tubing hanger in the tubing head four-way joint; and fixing the tubing hanger of the coiled tubing into the tubing head four-way joint. According to the method for putting in and taking out the coiled tubing being used as the production tubing string, the coiled tubing replaces a conventional tubing and is directly used a production tubing string, a standard gas production tree well head is achieved after construction, and the sealing effect of the well head can be ensured at the same time.

Description

technical field [0001] The invention relates to the technical field of petroleum production, in particular to a method for running in and out of a coiled tubing production string. Background technique [0002] The effective development of shale gas resources mainly benefits from the implementation of large-scale fracturing technology, which requires a sufficiently large fluid channel. The existing technology mainly implements large-scale fracturing construction directly through casing. After the fracturing is completed, the production string needs to be run under pressure. At present, the main methods used are the tubing under the snubbing machine and the coiled tubing under the coiled tubing machine. [0003] For the method of lowering the oil pipe with the working machine under pressure, the construction cost of the working machine under pressure is high, the working time is long, and the safety risk is great. [0004] For the coiled tubing method under the coiled tubing ...

AI Technical Summary

Problems solved by technology

At this time, there are the following problems: first, the wellhead structure has been changed; second, the main valve 1 cannot be used (because the main valve 1 needs to cooperate with ordinary tubing hangers to achieve sealing); the third is that the long-term sealing of the pipe string is unreliable ( Because the seal only depends on one inner rubber of the coiled tubing hanger), the risk of loss of seal is high when the wellhead pressure is high

Images