Double-layer steel pipe expansion type pipe external casing packer

Abstract

The invention relates to a double-layer steel pipe expansion type pipe external casing packer, which comprises an expansion base pipe, a packing unit, an upper joint and a lower joint, wherein the upper joint and the lower joint are processed at the two ends of the expansion base pipe, the packing unit is formed by installing one or more than one packing unit outside the expansion base pipe at intervals, each packing unit comprises an expansion outer pipe, upper and lower fixed pup joints and a rubber tube, the upper and lower fixed pup joints are connected with the two ends of the expansion outer pipe, the rubber tube is connected with the outer part of the expansion outer pipe, the expansion base pipe and the expansion outer pipe respectively adopt expansion steel pipe materials, the upper and lower ends of the expansion outer pipe are connected onto the expansion base pipe through the upper and lower fixed pup joints, and a pre-set expansion cavity is formed between the expansion outer pipe and the expansion base pipe. The external casing packer has the advantages that through the expansion of a double-layer steel pipe, the tight attachment of the steel pipe and the rubber tube to the ground layer is realized, the advantages of great packing outer diameter of the packer, high intensity, capability of complying with the well hole packing and the like are realized, and the external casing packer can be widely used in the fields of well completion such as segmented well completion and inter-layer packing.

Description

technical field [0001] The invention relates to the field of drilling and completion tools, in particular to provide a double-layer steel pipe expansion type external packer for segmented well completion and interlayer isolation. Background technique [0002] The outer pipe packer is an important tool in the process of petroleum cementing and selective well completion. It is connected with the casing and is a downhole tool used to seal the annular space between the casing and the well wall. Implement layer separation, it can carry out operation and production control according to layer, so as to effectively realize the segmented production of oil and gas wells and the interlayer isolation of complex formations. [0003] The existing outer casing packer mainly realizes outer casing sealing by two methods of rubber sleeve expansion sealing and self-expansion when encountering oil and water. The expansion sealing method of the rubber sleeve, through the action of the high-pres...

AI Technical Summary

Problems solved by technology

The hydraulic expansion type external packer usually uses drilling fluid as the expansion medium, and it is easy to seal failure in complex downhole environments such as high temperature and high pressure, and casing eccentricity; the cement slurry expansion type external packer uses cement slurry as the expansion medium. However, its construction technology is relatively complicated, causing serious construction accidents; oil / water self-expanding tubular packer adopts oil / water self-expanding rubber, which expands after encountering oil / water in the later stage to seal Formation, but its sealing effect is limited under high temperature and high pressure conditions, and the sealing strength of rubber is also limited after self-expansion, making it difficult to seal complex formations

[0004] Conventional outer casing packers have been widely used in the field of petroleum well completions to perform staged screen completion and interlayer isolation, protect and reduce oil layer pollution, and delay horizontal bottom water coning to a certain extent; but There are still problems such as limited sealing effect, easy damage of sealing rubber, and short sealing time.

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