# US 10,480,298 B2 · Bidirectional piston seals with pressure compensation > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 10,480,298 B2 - Document ID: US10480298B2 - Status: Granted - Kind: B2 - Application number: 15/632,310 - Filed: 2017-06-24 - Published: 2017-10-12 - Granted: 2019-11-19 - Earliest claimed: 2013-11-08 - Assignees: GE Oil & Gas ESP, Inc. - Applicants: GE Oil & Gas ESP, Inc. - Inventors: Brian Paul Reeves; Jifeng Wang; Chengbao Wang; Omprakash Samudrala - Web page: https://patentgrep.com/patent/US10480298B2 ## CPC - E21B 33/1285: {by fluid pressure} - E21B 33/1208: {characterised by the construction of the sealing or packing means (E21B33/1277 takes precedence)} - E21B 43/128: {Adaptation of pump systems with down-hole electric drives} - F04B 11/00: Equalisation of pulses, e.g. by use of air vessels; Counteracting cavitation - F04B 17/03: driven by electric motors - F04B 35/04: the means being electric - F04B 43/08: having tubular flexible members (F04B43/12 takes precedence) - F04B 43/107: the fluid being actuated directly by a piston - F04B 47/06: having motor-pump units situated at great depth - F04B 53/008: {Spacing or clearance between cylinder and piston} - F04B 53/02: Packing the free space between cylinders and pistons - F04B 53/08: Cooling; Heating; Preventing freezing - F04B 53/18: Lubricating - F04D 13/0653: {the motor being flooded} - F04D 13/10: adapted for use in mining bore holes - H02K 5/132: Submersible electric motors (H02K5/128 takes precedence) - E21B: EARTH OR ROCK DRILLING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR A SLURRY OF MINERALS FROM WELLS - F04B: POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS (machines for liquids, or pumps, of rotary-piston or oscillating-piston type F04C; non-positive-displacement pumps F04D; pumping of fluid by direct contact of another fluid or by using inertia of fluid to be pumped F04F) - F04D: NON-POSITIVE-DISPLACEMENT PUMPS (engine fuel-injection pumps F02M; ion pumps H01J41/12; electrodynamic pumps H02K44/02) - H02K: DYNAMO-ELECTRIC MACHINES (dynamo-electric relays H01H53/00; conversion of DC or AC input power into surge output power {H03K3/53}) ## Abstract An electric submersible pumping system for use in pumping fluids from a wellbore includes a motor, a pump driven by the motor, and a fluid expansion module connected to the motor. The fluid expansion module includes a piston seal housing and a piston assembly contained within the piston seal housing. The piston assembly includes a piston body having an exterior surface, a plurality of seals connected to the exterior surface of the piston body and a pressure equalization system. The pressure equalization system reduces a pressure differential between fluid in an annular space between the plurality of seals and fluid surrounding the first piston assembly. ## Claims ### Claim 1 An electric submersible pumping system for use in pumping fluids from a wellbore, the electric submersible pumping system comprising: a motor; a pump driven by the motor; and a fluid expansion module connected to the motor, wherein the fluid expansion module comprises: a piston seal housing; and a first piston assembly contained within the piston seal housing, wherein the first piston assembly comprises: a piston body having an exterior surface; a plurality of seals connected to the exterior surface of the piston body, wherein a space between the plurality of seals creates an annular space; and a pressure equalization system, wherein the pressure equalization system reduces a pressure differential between fluid in the annular space and fluid surrounding the first piston assembly. ### Claim 2 (depends on 1) The electric submersible pumping system of claim 1, wherein the pressure equalization system comprises: an equalization chamber; an inlet check valve connected to the equalization chamber, wherein the inlet check valve is configured to permit the introduction of fluid into the equalization chamber; and one or more pressure vents connected between the equalization chamber and the annular space. ### Claim 3 (depends on 2) The electric submersible pumping system of claim 2, wherein the pressure equalization system further comprises a release check valve connected to the equalization chamber, wherein the release check valve is configured to permit the release of fluid from the equalization chamber. ### Claim 4 (depends on 1) The electric submersible pumping system of claim 1, wherein each seal further comprises: a body; and an interior spring, wherein the interior spring is configured to exert an outward radial force against the body. ### Claim 5 (depends on 1) The electric submersible pumping system of claim 1, wherein the piston seal housing includes a polymer liner. ### Claim 6 (depends on 1) The electric submersible pumping system of claim 1, wherein the fluid expansion module further comprises a second piston assembly. ### Claim 7 (depends on 6) The electric submersible pumping system of claim 6, wherein the second piston assembly comprises: a piston body having an exterior surface; a plurality of seals connected to the exterior surface of the piston body, wherein a space between the plurality of seals creates an annular space; and a pressure equalization system, wherein the pressure equalization system reduces a pressure differential between fluid in the annular space and fluid surrounding the second piston assembly. ### Claim 8 (depends on 1) The electric submersible pumping system of claim 1, wherein the fluid expansion module further comprises: a bag seal housing; and a bag seal assembly within the bag seal housing. ### Claim 9 (depends on 8) The electric submersible pumping system of claim 8, wherein the bag seal assembly further comprises: a bag support; and a bladder secured to the bag support. ### Claim 10 (depends on 9) The electric submersible pumping system of claim 9, wherein the bag seal assembly further comprises one or more discharge ports and wherein each of the one or more discharge ports is configured as a one-way check valve that places the interior of the bladder in fluid communication with the wellbore when opened. ### Claim 11 (depends on 1) The electric submersible pumping system of claim 1, wherein the fluid expansion module further comprises a fluid exchange assembly and wherein the fluid exchange assembly comprises: a solids screen; exchange ports; and wherein the fluid exchange assembly is configured to place the exterior of the bladder in fluid communication with the wellbore. ### Claim 12 (depends on 1) The electric submersible pumping system of claim 1, further comprising a seal section between the motor and the pump, wherein the seal section comprises: a shaft; one or more mechanical seals; and one or more relief valves. ### Claim 13 A system for accommodating the expansion of motor lubricant in a motor within an electric submersible pump used for removing fluids from a wellbore, the system comprising: a seal section connected to a first end of the motor; and a fluid expansion module connected to a second end of the motor, wherein the fluid expansion module has a longitudinal axis and wherein the fluid expansion module comprises at least one piston assembly, wherein the at least one piston assembly moves along the longitudinal axis of the fluid expansion module in response to an expansion of the motor lubricant, wherein the at least one piston assembly comprises: a piston body having an exterior surface; a plurality of seals connected to the exterior surface of the piston body, wherein a space between the plurality of seals creates an annular space; and a pressure equalization system, wherein the pressure equalization system reduces a pressure differential between fluid in the annular space and fluid surrounding the at least one piston assembly. ### Claim 14 (depends on 13) The system of claim 13, wherein the fluid expansion module further comprises a bag seal assembly, wherein the bag seal assembly includes a bladder that expands in response to movement of the at least one piston assembly. ### Claim 15 (depends on 14) The system of claim 14, wherein the fluid expansion module further comprises a fluid exchange assembly that places the exterior of the bladder in fluid communication with the wellbore. ### Claim 16 A fluid expansion module for use in an electric submersible pumping system that includes a pump driven by a fluid-filled motor, the fluid expansion module comprising: a piston seal housing in fluid communication with the fluid-filled motor; and a first piston assembly contained within the piston seal housing, wherein the first piston assembly comprises: a piston body having an exterior surface; a plurality of seals connected to the exterior surface of the piston body, wherein a space between the plurality of seals creates an annular space; and a pressure equalization system, wherein the pressure equalization system reduces a pressure differential between fluid in the annular space and fluid in the piston seal housing. ### Claim 17 (depends on 16) The fluid expansion module of claim 16, wherein the pressure equalization system comprises: an equalization chamber; one or more pressure vents connected between the equalization chamber and the annular space; and one or more check valves in fluid communication with the equalization chamber. ### Claim 18 (depends on 16) The fluid expansion module of claim 16, wherein the fluid expansion module further comprises a second piston assembly. ### Claim 19 (depends on 18) The fluid expansion module of claim 18, wherein the second piston assembly comprises: a piston body having an exterior surface; a plurality of seals connected to the exterior surface of the piston body, wherein a space between the plurality of seals creates an annular space; and a pressure equalization system, wherein the pressure equalization system reduces a pressure differential between fluid in the annular space and fluid surrounding the second piston assembly. ### Claim 20 (depends on 19) The fluid expansion module of claim 19, wherein the pressure equalization system of the second piston assembly comprises: an equalization chamber; an inlet check valve connected to the equalization chamber, wherein the inlet check valve is configured to permit the introduction of fluid into the equalization chamber from the piston seal housing; one or more pressure vents connected between the equalization chamber and the annular space; and a release check valve connected to the equalization chamber, wherein the release check valve is configured to permit the release of fluid from the equalization chamber to the piston seal housing.