Reentry method of later-operation pipe column of multi-branch well

Abstract

The invention discloses a reentry method of a later-operation pipe column of a multi-branch well, comprising the following steps of: (1) respectively anchoring two guide sleeves above a window of a side branch during or after well drilling and completion, and defining an included angle between projections of a guide groove and the side branch on a horizontal plane as a well bore guide angle, wherein the well bore guide angle is preset; (2) reentering a pipe column of a main branch, wherein a guide head downwards moves along the center of a main well bore all the time under the centering of a centering guide to guide the later-operation pipe column into the well bore of the main branch; and (3) reentering a pipe column of the side branch, i.e. starting to reenter the pipe column of the side branch under the match of a guide key and the guide groove, wherein when the preset well bore guide angle of the side branch, which has degrees the same as that of a pipe column guide angle, is met, a bend of a bent guide shoe just faces to the window of the side branch. The invention realizes the selective later-operation pipe column reentry of more than three multi-branch well bores and enhances the pipe column reentry efficiency and reliability.

Description

technical field [0001] The invention relates to the technical field of pipe string reentry in branch wells in oil and gas fields, in particular to a selective entry method for post-operation pipe strings in multi-branch wells. Background technique [0002] At home and abroad, most of the selective entry technologies for post-operation pipe strings in lateral wells are associated with the completion system. For example, the expansion pipe completion system is to guide the post-stage pipe string through re-running the deflector and cooperating with the guide surface of the expansion pipe. selective entry. In the perforated casing or liner re-perforated well completion system, the guider is lowered into the upper extension tube of the lower branch liner, and the guider seals the upper branch window, and the pipe string enters the lower branch wellbore, and the lower branch is blocked. The branch channel enters the upper branch wellbore. [0003] For example, the publication n...

AI Technical Summary

Problems solved by technology

The deflection force of this type of tool elbow is generally driven by hydraulic pressure, but the post-operation string is often not or not allowed to be pressed, such as perforating and fracturing operations, if the pressure is pressed when the string is lowered, the packer may be halfway Setting or perforating gun bursting midway

The end of some operating strings is unblocked and cannot hold up pressure, so the adaptability is poor

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