# US 4,395,061 A · Swivel unit

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- Number: US 4,395,061 A
- Document ID: US4395061A
- Status: Granted
- Kind: A
- Application number: 06/273,821
- Filed: 1981-06-15
- Granted: 1983-07-26
- Earliest claimed: 1981-06-15
- Assignees: Hughes Tool Company
- Inventors: Lawrence E. Helzer
- Web page: https://patentgrep.com/patent/US4395061A

## CPC

- E21B 49/08: Obtaining fluid samples or testing fluids, in boreholes or wells
- E21B 21/02: Swivel joints in hose-lines
- E21B 33/127: with inflatable sleeve (E21B33/122, E21B33/124 take precedence)
- E21B: EARTH OR ROCK DRILLING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR A SLURRY OF MINERALS FROM WELLS

## Abstract

A swivel unit for inflatable packer drill stem test tools has an outer housing with a lower end adapted for connection to the drill stem and an upper end. An inner shaft has a base portion received within the outer housing and has a neck portion which protrudes from the outer housing. Tapered roller bearings located between the outer housing and inner shaft at opposing ends of the inner shaft base portion rotatably mount the outer housing about the inner shaft. The outer housing has a shoulder formed in its external surface for receiving the derrick elevators and supporting the test tool assembly.

## Claims

### Claim 1

A swivel unit for an inflatable packer drill stem test tool assembly, comprising:
an outer housing having a lower end adapted for connection to said drill stem test tool and having an upper end;
an inner shaft having a base portion received within said outer housing and having a neck portion protruding from said outer housing;
bearing means for rotatably mounting said outer housing about said inner shaft; and
wherein said outer housing has a downwardly facing shoulder formed in the exterior surface thereof for supporting said assembly.

### Claim 2

A swivel unit for an inflatable packer drill stem test tool assembly, comprising:
an outer housing having a lower end adapted for connection to said drill stem test tool and having an upper end;
an inner shaft having a base portion received within said outer housing and having a neck portion protruding from said outer housing;
tapered roller bearings located between said outer housing and inner shaft at opposing ends of said inner shaft base portion for rotatably mounting said outer housing about said inner shaft; and
wherein said outer housing has a shoulder formed therein for supporting said assembly.

### Claim 3

A swivel unit for an inflatable packer drill stem test tool assembly of the type used in a drill rig having a traveling block, a hook supported from the traveling block, and derrick elevators supported from the hook by elevator links, comprising:
an outer housing having a lower end adapted for connection to said drill stem test tool and having an upper end;
an inner shaft having a base portion received within said outer housing and having a neck portion protruding from said outer housing;
tapered roller bearings located between said outer housing and inner shaft at opposing ends of said inner shaft base portion for rotatably mounting said outer housing about said inner shaft; and
wherein said outer housing has a shoulder formed therein for receiving said derrick elevators and thereby supporting said assembly.

### Claim 4 (depends on 3)

The swivel unit of claim 3, wherein said opposing tapered roller bearings are contained within the upper end of said outer housing above said shoulder.

### Claim 5 (depends on 4)

The swivel unit of claim 4, wherein the length of the assembly above said shoulder is sized to fit between said elevators and said hook while the distance between said opposing tapered roller bearing locations is maximized.