US 5,944,107 A · Method and apparatus for establishing branch wells at a node of a parent well

Abstract

A method and apparatus for creating multiple branch wells from a parent well is disclosed. A multiple branching sub is provided for placement at a branching node of a well. Such sub includes a branching chamber and a plurality of branching outlet members. The outlet members during construction of the branching sub, have previously been distorted into oblong shapes so that all of the branching outlet members fit within an imaginary cylinder which is coaxial with and substantially the same radius as the branching chamber. After deployment of the branching sub via a parent casing in the well, a forming tool is lowered to the interior of the sub. The outlet members are extended outwardly by the forming tool and simultaneously formed into substantially round tubes. Next, each outlet member is plugged with cement, after which each branch well is drilled through a respective outlet member. If desired, each branch may be lined with casing and sealed to a branching outlet by means of a casing hanger. A manifold placed in the branching chamber controls the production of each branch well to the parent well.

Claims25

Dependent claims

An apparatus for casing a borehole, said apparatus comprising:

a string of well casing;
and
a multiple branching sub on the lowermost end of said well casing string, wherein said multiple branching sub includes
a branching chamber having an open first end of cylindrical shape and a second end, said branching chamber in sealed connection at said first end with said well casing;
and
multiple branching outlet members, each of which is integrally connected to said second end of said branching chamber, each of said multiple branching outlet members being in fluid communication with said branching chamber, said sub characterized by:
a retracted position for insertion into said borehole in which each of said multiple outlet members is substantially totally within an imaginary cylinder which is coaxial with and of substantially the same radius as said first end of said branching chamber;
and
an expanded position in which at least one of said multiple outlet members extends from said branching chamber in a path outwardly of said imaginary cylinder.

6 more elements

A method of installing a multiple branching sub in a borehole where said sub includes a branching chamber having a cylindrical first end and a second end, and multiple branching outlet members each of which is connected to said second end of said branching chamber and are disposed in a retracted position in which each of said multiple outlet members is substantially totally within an imaginary cylinder which is coaxial with, and of substantially the same radius as, said cylindrical first end of said branching chamber, the method comprising the steps of:

connecting said first end of said branching chamber of said sub to a lower end of a casing string;
running said casing string and said sub into a borehole to a node position where a branch borehole is to be provided;
running a forming tool through said casing string into said branching chamber of said sub;
orienting said forming tool within said sub in order to insert said forming tool into at least one of said multiple outlet members at said second end of said branching chamber;
and
expanding said at least one of said multiple outlet members with said forming tool until said at least one outlet member extends from a connection at said second end of said branching chamber in a path outwardly of said imaginary cylinder.

3 more elements

Dependencies are inferred from the claim text.

Method and apparatus for establishing branch wells at a node of a parent well

Life of this patent

Method and apparatus for establishing branch wells at a node of a parent well

Life of this patent

Abstract

Claims25