Well cementation and completion structure and process for cased branch well with temporarily-sealed opening

Abstract

The invention discloses a well cementation and completion structure and a process for a cased branch well with a temporarily-sealed opening. An upper branch casing of the well cementation and completion structure comprises a bent guide shoe positioned in an upper branch well, an upper branch tail pipe connected with the bent guide shoe and a perforated casing connected with the upper branch tail pipe, wherein the end, connected with the upper branch tail pipe, of the perforated casing, is positioned in the upper branch well, while the other end is fixed in a main casing; a sealing material isarranged in the opening of the perforated casing; the main casing is arranged in a main well; a lower branch casing is arranged in a lower branch well; a guide sleeve, an orientator and a whipstock are arranged in the main casing; the guide sleeve is positioned above a joint where the perforated casing and the main sleeve are fixed; the orientator is positioned above the lower branch casing; the whipstock is positioned above the orientator; and a filler is arranged in an inner through hole of the orientator. The structure and the process have the advantages of realization of quick well completion of a plurality of branch wells, easy tail pipe perforation operation, high perforation quality, no damage to upper well walls in the perforation of the tail pipe and no need of casing off and fishing lining pipes.

Description

Technical field [0001] The invention relates to a cementing and completion structure and a method for branch wells in oil and gas fields, and in particular to a cementing and completion structure and a process for temporarily sealing a perforated casing branch well. Background technique [0002] At present, multilateral well technology is an advanced technology that can reduce oil and gas development costs and improve oil and gas recovery, but it is also a difficult drilling technology. With the rapid development of drilling technology, the application of multilateral well drilling technology will More and more widespread. For example, Chinese Patent No. 200410004401.0 discloses the opening and reentry device and the opening and reentry method of oil and gas branch wells. Its application date is February 19, 2004, and the authorization announcement date is June 21, 2006. Its oil and gas branch The well opening and reentry device includes the branch well casing opening device and...

AI Technical Summary

Problems solved by technology

The problems of adopting this structure and method are: it is difficult to open the liner pipe, and the quality of the hole is poor; the upper well wall is damaged when the liner is opened.

The problems with this structure and method are: the liner needs to be lowered and fished; the window and the main and branch holes need to be repaired

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