US 5,472,048 A · Parallel seal assembly

Abstract

A scoophead/diverter assembly functions to orient and anchor multiple tubing strings at the Y-juncture in an oil or gas well with multiple lateral wellbores. An important advantage of this arrangement is to provide communication to multiple reservoirs or tap different locations within the same reservoir, and enable re-entry to these wellbores for remediation and stimulation. The large bore of the scoophead enables a secondary wellbore's production tubing (liner) to pass through until the top of the liner is in the scoophead. In order to effect a seal inside the scoophead, a novel offset parallel seal assembly with centralizer is utilized. This parallel seal assembly carries compressive loads on the primary wellbore side, and has a shear out mechanism on the secondary wellbore side. This seal assembly also may constitute the connection between the scoophead and a selective re-entry tool (SRT). The SRT is a tool that ties the two separate tubing strings below it into a single production tubing string to surface or the next lateral. This parallel seal assembly has two seal assemblies parallel to one another with one seal assembly being larger diameter and longer than the other. The larger seal assembly seals into the seal bore of a tie back sleeve which is latched into the scoophead, and is attached to the top of the secondary wellbore's production tubing string. The smaller seal assembly seals in the small bore of the scoophead. The smaller assembly acts to isolate the primary wellbore. The larger seal assembly is longer than the smaller to allow it to enter its bore and align the assembly. The alignment is accomplished by trapping the larger seal assembly in its bore and trapping the centralizer in the wellbore. This positively limits the rotational mis-alignment available to the smaller seal assembly prior to stabbing into the scoophead.

Claims22

Dependent claims

A parallel seal assembly comprising:

a seal assembly housing;
a first seal assembly extending from said housing, said first seal assembly comprising a first tubing having an exterior cylindrical surface with a first seal disposed along a portion of said surface;
a second seal assembly extending from said housing, said second seal assembly comprising a second tubing having an exterior cylindrical surface with a second seal disposed along a portion of said surface;
wherein said first seal assembly is longer than said second seal assembly by a distance "D" and wherein said first and second seal assembly are permanently disposed across from one another in a parallel configuration.

1 more element

Dependencies are inferred from the claim text.

Parallel seal assembly

Life of this patent

Parallel seal assembly

Life of this patent

Abstract

Claims22