Method for well cementation drilling-free blind plate circulating well cementation of horizontal well

Abstract

The invention provides a method for well cementation drilling-free blind plate circulating well cementation of a horizontal well. A body of a large-channel horizontal well cementation drilling-free blind plate circulating well cementation device formed by organic combination of an elongated two-stage parallel connection seat sealing sleeve outer packer and an inner-pipe-free drilling-plug-free classification cementing device is connected with a sleeve, a circulating channel between the sleeve and a well wall is formed, pad fluid is injected to clean the well wall; after the well wall is cleaned, a self-locking returnable primary switch sliding sleeve rubber plug is placed from a well opening cement head and is pumped into the inner-pipe-free drilling-plug-free classification cementing device, the elongated two-stage parallel connection seat sealing sleeve outer packer undergoes expanding sealing, a circulating hole of the inner-pipe-free drilling-plug-free classification cementing device is opened, cementing well cementation is performed; after cement is injected, a self-locking returnable secondary replacing pressing rubber plug is placed from the well opening cement head, displacement fluid is utilized to press the self-locking returnable secondary replacing pressing rubber plug, the self-locking returnable secondary replacing pressing rubber plug enters the inner-pipe-free drilling-plug-free classification cementing device, the circulating hole of the inner-pipe-free drilling-plug-free classification cementing device is closed until cement slurry is solidified, a drill performs downward drilling to salvage accessories in the inner-pipe-free drilling-plug-free classification cementing device, a drafting process is performed, and well cementation work is finished.

Description

technical field [0001] The invention relates to a drilling-free blind plate circulation cementing method for horizontal well cementing used for well completion, which belongs to the field of oil field technology development. Background technique [0002] At present, in the completion technology of horizontal wells, in order to make the oil layer have a large exposed area, avoid the damage of the cement slurry to the oil layer, and effectively protect the oil and gas layers, the completion method of precision sand filter tube is mostly used. The staged cementing process of screen top cement injection is required. During the implementation of this process, the casing accessories such as drilling rubber plugs and grading hoops are located at the position of the large well deviation angle of the downhole pipe string. When drilling the plugs, there are problems such as unclean cleaning of the accessories in the pipe, wear and tear of the casing or free section tripping, damage to...

AI Technical Summary

Problems solved by technology

The disadvantage of the conventional graded cementing device is that the drilling speed must be strictly controlled when running the casing to prevent the phenomenon of drilling stuttering and slippage. tool structure

During the drilling and grinding process, not only the casing is easily damaged, but also the operation takes a long time

These shortcomings of the conventional graded cementing device restrict its use value, and cannot well meet and meet the requirements of cementing production operations

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