Coiled tubing drilling and milling method for plugging

Abstract

The invention discloses a method for drilling and milling of bulkheads of a continuous oil pipe and belongs to the field of oil-gas wells. The method comprises the following steps that (1) a pump injection device is connected with a continuous oil pipe device, and then the continuous oil pipe in the continuous oil pipe device is connected with a flushing tool to form a flushing device; (2) the flushing device enters a horizontal well through a Christmas tree at a well mouth of the horizontal well and detects the position of the bulkheads in the horizontal well; (3) when the position of the bulkheads is detected, the pump injection device is opened to enable drilling washing liquid to be injected into the horizontal well for drilling and milling of the bulkheads through the continuous oil pipe; (4) when the residual bulkheads cannot be cleared away by the flushing device, the continuous oil pipe is connected with a drilling and milling tool to form a drilling and milling device so as to drill and mill the residual bulkheads; and (5) the step (3) and / or (4) are / is repeated till footage does not occur in repeatedly flushing and / or drilling and milling of the horizontal well, then direct flushing is conducted till the liquidity of returning liquid in a backflow pipe which is connected with the Christmas tree is consistent with that of the drilling washing liquid, small-displacement cycle is kept, and the drilling and milling device is pulled out.

Description

technical field [0001] The invention relates to the field of oil and gas wells, in particular to a method for drilling and milling plugs with coiled tubing. Background technique [0002] With the continuous development of oilfields, horizontal wells have become an important way to increase single well production, improve the development effect and improve recovery. In particular, the application of water shutoff technology has made the comprehensive interlayer and intralayer management of horizontal wells a reality, but this process has the phenomenon that plugging agent residues are easily formed in the horizontal section after water shutoff, which makes subsequent operations more difficult. [0003] Drilling and milling plugging agent residue technology has become a key technology to solve the follow-up problem of water plugging in horizontal wells. The conventional vertical well drilling and milling process is realized by ordinary tubing plus drilling and milling tools, ...

AI Technical Summary

Problems solved by technology

The conventional vertical well drilling and milling process is realized by ordinary tubing plus drilling and milling tools, but in horizontal wells, due to restrictions on the outer diameter of the tubing, coupling size and wellbore trajectory, it is difficult to run the tool, and the horizontal well is continuously connected during the drilling and milling process. Type chamfered oil pipe, long construction period, heavy workload, high labor intensity, and because the circular flushing cannot be established when connecting the flat chamfered oil pipe, it is easy to cause the problem of drill sticking, resulting in the inability to pull out the drilling and milling pipe string, so the conventional The drilling and milling process is not suitable for drilling and milling operations in horizontal wells

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