Submersible chemical injection pump

• US 4,582,131 A
• Filed: 09/26/1984
• Issued: 04/15/1986
• Est. Priority Date: 09/26/1984
• Status: Expired due to Fees

• Current Assignee: Baker Hughes Incorporated (Baker Hughes Company)
• Original Assignee: Hughes Tool Company (Baker Hughes Company)
• Inventors: Plummer, Leonard M., Banta, Derry E., Wilczek, Vance A.
• Primary Examiner(s): NOVOSAD, STEPHEN
• Assistant Examiner(s): Bagnell, David J.
• Application Number:
  US06/654,824
• Time in Patent Office: 566 Days
• Field of Search: 166/68, 166/244 C, 166/300, 166/304, 166/310, 166/311, 166/312, 166/371, 166/106, 166/101, 166/183, 166/54, 166/72, 166/105-112, 166/68.5
• US Class Current: 166/68
• CPC Class Codes: E21B 37/06 using chemical means for preventing or limiting , e.g. eliminating, the deposition of paraffins or like substances
• CPC Class Codes: E21B 41/02 in situ inhibition of corrosion in boreholes or wells
• CPC Class Codes: Y10S 166/902 for inhibiting corrosion or coating

Abstract

An electrical submersible well pump installation has a downhole secondary pump for pumping scale inhibiting chemicals below the downhole pumping assembly. The downhole pumping assembly includes a centrifugal primary pump driven by an electrical motor located below the pump and separated by a seal section for preventing well fluids from entering the motor. The secondary pump is also driven by the motor and is located between the seal section and the primary pump. The secondary pump has an intake connected to a tube that extends upwardly above the intake of the primary pump. The secondary pump has a discharge port connected to a discharge tube that extends downwardly to a point below the motor. Chemicals introduced at the surface into the annulus flow downwardly into the intake of the secondary pump and are discharged below the motor. The secondary pump has an inverted impeller and diffuser that have a discharge on the lower end for discharging fluids downwardly.

Claims

1. In a well installation, having casing, a string of tubing extending to a downhole centrifugal pumping assembly, defining an annulus between the casing and the tubing and pumping assembly, and means at the surface for introducing inhibiting chemicals into the annulus, the pumping assembly including a centrifugal primary pump driven by an electrical motor located below the pump and separated by a seal section for preventing well fluids from entering the motor, the improvement comprising in combination:

a centrifugal secondary pump having an upper end adapted to be connected to the bottom of the primary pump and a lower end adapted to be connected to the top of the seal section;

the secondary pump having an intake port on its upper end adapted to be connected to an intake tube that extends above an intake of the primary pump, terminating in the annulus;

the secondary pump having a discharge port on its lower end adapted to be connected to a discharge tube that extends downwardly through the annulus alongside the motor to a point in the annulus below the motor, for pumping inhibiting chemicals drawn from the annulus to a location below the motor, which then flow upwardly around the motor and into the intake of the primary pump.

2. In a well installation having a casing, a string of tubing extending to a downhole centrifugal pumping assembly, defining an annulus between the casing and the tubing and pumping assembly, and means at the surface for introducing inhibiting chemicals into the annulus, the pumping assembly including a centrifugal primary pump which has an intake on its lower end and is driven by an electrical motor located below the pump, the improvement being a centrifugal secondary pump adapted to be connected to the pumping assembly, comprising in combination:

a tubular housing having an intake port on its upper end adapted to be connected to an intake tube that extends upwardly in the annulus to a point above the intake of the primary pump, and a discharge port on its lower end;

a shaft rotatably mounted in the housing and adapted to be driven by the motor; and

an impeller and diffuser assembly mounted in the housing, having an intake facing upwardly in the housing and a discharge located below the intake of the impeller and diffuser assembly and facing downwardly in the housing, for pumping inhibiting chemicals drawn from the annulus downwardly into the well, to be then drawn upwardly into the intake of the primary pump.

3. In a well installation having casing, a string of tubing extending to a downhole centrifugal pumping assembly, defining an annulus between the casing and the tubing and pumping assembly, and means at the surface for introducing inhibiting chemicals into the annulus, the pumping assembly including a centrifugal primary pump having an intake on its lower end and driven by a shaft of an electrical motor located below the pump and separated by a seal section for preventing well fluids from entering the motor, the improvement being a centrifugal secondary pump, comprising in combination:

a tubular housing;

connection means at the upper end of the housing for connecting the housing to the bottom of the primary pump;

connection means at the lower end of the housing for connecting the housing to the upper end of the seal section;

a shaft extending through the housing for rotation by the shaft of the motor;

an impeller and diffuser assembly mounted in the housing, having an intake facing upwardly in the housing and a discharge located below the intake of the impeller and diffuser assembly and facing downwardly for pumping fluid downwardly through the housing;

an intake tube adapted to be connected to the intake port and extending upwardly to a point in the annulus above the intake of the primary pump;

a discharge port in the housing below the impeller and diffuser assembly; and

a discharge tube adapted to be connected to the discharge port and extending downwardly alongside the motor to a point in the annulus below the motor, for pumping inhibiting chemicals introduced into the annulus at the surface to a location below the motor, to then flow upwardly into the intake of the primary pump.