US 5,343,944 A · Self aligning stuffing box for pumpjack units

Abstract

A self aligning stuffing box for a pumpjack unit of the type having a polished rod reciprocatingly extending therethrough and downhole to a pump located at the lower end of the borehole. The stuffing box is an annular main body having a tubing adaptor at the lower end by which it can be mounted to the upper end of a well bore. A spool receiving cavity is located within the main body concentrically respective to the polished rod, and an annular spool is received within the cavity. The polished rod reciprocatingly extends through the spool and main body. A seal assembly is mounted to the inner surface of the spool for sealingly engaging the polished rod. The spool cooperates with the cavity to form a lubrication chamber that extends outwardly and about the spool. The spool moves within the spool receiving cavity radially of the passageway to align the polished rod with the wellbore. The adaptor forms a pack-off that isolates the seal from the wellbore, and provision is made by which the seal assembly can be replaced without removing the polished rod from the pumpjack unit.

Claims20

Dependent claims

A self aligning stuffing box for a pumpjack unit of the type having a polished rod reciprocatingly extending therethrough and downhole into a borehole;

said stuffing box comprising:
an annular main body having an upper end opposed to a lower end, a closure member at the upper end, and adaptor means at the lower end by which said stuffing box can be mounted respective to the borehole;
a spool receiving cavity formed within said main body, a shoulder within said main body that forms a cavity floor, an annular spool received within said spool receiving cavity through which the polished rod reciprocatingly extends;
said spool having inner and outer surfaces and upper and lower faces, a seal assembly mounted to the inner surface of the spool for sealingly engaging the polished rod;
whereby, said spool can move within said spool receiving cavity radially of said cavity and thereby align the polished rod with the borehole;
an oil reservoir formed within the spool receiving cavity and outwardly of the spool;
said closure member has a lower face, seal means by which said upper face of said spool engages said lower face of said closure member;
and seal means by which said lower face of said spool engages said lower shoulder of the main body.

5 more elements

An improved stuffing box for a pumpjack unit of the type having a polished rod reciprocatingly received through the stuffing box in a sealed manner therewithin for producing a wellbore comprising:

a passageway extending through said stuffing box through which the polished rod is reciprocatingly received;
said passageway includes an inner wall surface that defines an upwardly opening annular chamber within said stuffing box that is aligned in parallel relationship respective to said axial passageway;
a closure member affixed to the upper end of said chamber;
an annular spool having opposed flanges;
a spool passageway axially aligned with the polished rod;
seal means mounted within said spool passageway for sealingly engaging the reciprocating polished rod;
said spool is received within said chamber and forms a lubrication chamber between said spool and the inner wall surface to permit movement of said spool radially of said chamber and thereby align the polished rod with the wellbore.

4 more elements

In a pumpjack unit having a polished rod reciprocatingly received through a stuffing box in a sealed manner therewithin;

the stuffing box being attached to the upper end of 4 a production tubing string by an adaptor;
the combination of said stuffing box and adaptor comprising:
an upwardly opening annular chamber within said stuffing box;
a passageway extending through the annular chamber and through said stuffing box through which the polished rod is reciprocatingly received;
a closure member for said stuffing box, said closure member forms a chamber roof, a floor in said stuffing box that forms a bottom of the annular chamber;
an annular spool having a spool passageway and opposed flanges;
a seal assembly mounted in the spool passageway for reciprocatingly receiving the polished rod;
said spool is received within said chamber with said opposed flanges, respectively, slidably engaging the roof and floor, respectively, of said annular chamber;
said chamber has an interior wall spaced from said spool, a lubrication chamber jointly formed by said spool, said interior wall, and said chamber roof and floor within which the spool can move radially of said chamber wall and thereby align the polished rod with the production tubing string.

6 more elements

Dependencies are inferred from the claim text.

Self aligning stuffing box for pumpjack units

Life of this patent

Self aligning stuffing box for pumpjack units

Life of this patent

Abstract

Claims20