US 5,628,516 AGranted

Sealing assembly for rotary oil pumps having means for leaks detection and method of using same

OwnerEdward Grenkeinventor

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Abstract

An assembly for restraining oil leakage in a rotary oil well pump includes a stationary member and a rotary member. The rotary member is secured to the rotating rod and is sealed against the rod by conventional compressed packing. The rotary member has a cylindrical portion rotating within a cylindrical recess of the stationary member, with an annular recess defined between them. The recess contains two or more annular seal cartridges stacked one after the other in the annular space. The cartridges are designed to individually resist the ingress of the pressurized oil, so that leakage takes place sequentially past the individual cartridges. Leak passages are provided in the stationary member and are in communication with each of the cartridges respectively. When oil appears at any given leak passage, this signifies that the oil has bridged the defences of that cartridge and any cartridge or cartridges which are upstream of the leaking cartridge.

Claims19

Dependent claims

For use with an oil well having a top end and a bottom end, the combination of:

a) a downhole pump which includes a rotor and a stator, and which is adapted for positioning within and adjacent said bottom end of the well, an elongate rod adapted to extend down the well and support the rotor for rotation, the rod being adapted to transmit rational motion to the rotor from a means for generating rational torque, and
b) an assembling for restraining oil leakage, comprising:
a stationary first member defining a through-bore for the rod, and a substantially cylindrical recess coaxial with said bore, the cylindrical recess being defined by a cylindrical wall, the first member having an external wall,
a rotary second member also defining a through-bore, the rod extending through the through-bore of the second member and rotating therewith, the second member having a substantially cylindrical portion received coaxially in said recess, the cylindrical portion being defined by an outer cylindrical surface which has a smaller diameter than the recess so as to leave an annular space between the recess and the cylindrical surface, the annular space having an upstream end where oil under pressure seeks to enter the space, and a downstream end opposite the upstream end,
a plurality of annular seal cartridges stacked within said annular space, each seal cartridge having, in axial section;
a knife-edge corner slidably contacting said cylindrical portion, a first open space downstream of the knife-edge corner and adjacent the cylindrical portion, a second open space adjacent the cylindrical wall, a passageway means through which the two spaces are in communication, and means defining a leak passage through the first member, the leak passage communicating the respective open spaces with said external wall, and
plug means for closing at least one of the passages.

4 more elements

A method for restraining oil leakage in a pump for oil wells in which an elongate rod supports and rotates the rotor of a down-hole pump, utilizing an assembly including a stationary first member defining a through bore for the rod and a substantially cylindrical recess coaxial with said bore, the cylindrical recess being defined by a cylindrical wall, the first member having an external wall, a rotary second member also defining a through-bore, the rod extending through the through-bore of the second member and rotating therewith, the second member having a substantially cylindrical portion received coaxially in said recess, the cylindrical portion being defined by an outer cylindrical surface with a smaller diameter than the recess so as to leave an annular space between them, the annular space having an upstream end where oil under pressure seeks to enter the space, and a downstream end opposite the upstream end;

said method comprising the steps;
a) providing a plurality of stacked annular seal cartridges within said annular space, each cartridge having, in axial section:
a knife edge corner in sliding contact with said cylindrical portion, a first open space downstream of said corner and adjacent the cylindrical portion, a second open space adjacent the cylindrical wall, and passageway means through which the two spaces are in communication,
b) providing, for each seal cartridge, a leak passage through he first member, each leak passage communicating the respective open spaces with said external wall,
c) injecting a lubricant through the leak passage of the furthest upstream seal cartridge and then plugging that leak passage, while leaving open the leak passage of a seal cartridge downstream of the furthest upstream cartridge,
d) monitoring the left-open leak passage for leaking oil, and
e) when such leaking oil is detected, shutting down the pump and replacing at least those seal cartridges past which oil has leaked.

4 more elements

Dependencies are inferred from the claim text.

Facts

Application: 08/678,951Filed 12 Jul 1996 · continuation
Priority: 29 Aug 1994
Granted: 13 May 1997
Term ends: Not estimatedThe source records don’t support an estimate.

Classification6 codes

F04C 15/0038
For other than the working fluid, i.e. the sealing arrangements are not between working chambers of the machine: shaft sealings specially adapted…
E21B 33/085
Wipers; Oil savers: rotatable packing means, e.g. rotating blow-out preventers
F16J 15/004
Comprising at least two sealings in succession: forming of recuperation chamber for the leaking fluid
F04C
Rotary-piston, or oscillating-piston, positive-displacement machines for liquids