# US 11,994,012 B2 · Rodless pump and multi-sealing hydraulic sub artificial lift system > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 11,994,012 B2 - Document ID: US11994012B2 - Status: Granted - Kind: B2 - Application number: 18/299,939 - Filed: 2023-04-13 - Published: 2023-08-10 - Granted: 2024-05-28 - Earliest claimed: 2020-07-10 - Assignees: Digital Downhole, Inc. - Applicants: Digital Downhole Inc. - Inventors: Austin J. Shields - Web page: https://patentgrep.com/patent/US11994012B2 ## CPC - E21B 43/129: {Adaptations of down-hole pump systems powered by fluid supplied from outside the borehole (gas-lift E21B43/122; jet pumps E21B43/124)} - F04B 7/02: the valving being fluid-actuated - F04B 9/109: having plural pumping chambers - F04B 47/04: the driving means incorporating fluid means - F04B 47/08: the motors being actuated by fluid - F04B 53/12: arranged in or on pistons - F04B 53/14: Pistons, piston-rods or piston-rod connections - 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) ## Abstract Oil and gas companies worldwide strive to improve artificial lift efficiencies to minimize environmental footprint and lower operational expense. In order to lower artificial lift costs, the traditional rod pump must be replaced and improved upon. The present invention of the rodless pump and multi-sealing hydraulic sub is an optimized hydraulic pumping system that eliminates rod wear, lowers pump intake pressure, and extends the reserve life of oil and gas wells regardless of casing configuration or depth. Lowering the pump's intake pressure in an oil and gas well by using a positive displacement pump such as the present invention will allow maximum hydrocarbon reserves to be produced with minimal energy consumption to power the pump. The superior surface seals and smaller footprint of the rodless pump eliminate the possibility of surface hydrocarbon leaks, minimizing environmental impact. ## Claims ### Claim 1 A downhole hydraulic pump adapted to be disposed within a wellbore, the pump comprising: a first working piston having a first surface in contact with a power fluid and a second surface in contact with a wellbore fluid; a second working piston having a first surface in contact with a power fluid and a second surface in contact with a wellbore fluid; a connecting rod coupling the first working piston to the second piston; a first working chamber defined at least in part by the first surface of the first working piston; a second working chamber defined at least in part by the first surface of the second working piston; a seal arrangement respectively coupling a first hydraulic line from the surface to the first working chamber and a second hydraulic line from the surface to the second working chamber, wherein pressure applied via at least one of the first hydraulic line and the second hydraulic line causes reciprocation of the working pistons and wherein the first and second hydraulic lines are separate from production tubing disposed in the wellbore; and a flow path comprising one or more check valves wherein the one or more check valves are actuated by fluid pressure changes caused by reciprocation of the working pistons, thereby permitting wellbore fluid to be pumped to the surface. ### Claim 2 (depends on 1) The downhole hydraulic pump of claim 1 wherein the flow path is disposed within the connecting rod. ### Claim 3 (depends on 1) The downhole hydraulic pump of claim 1 wherein pressure is alternately applied via the first hydraulic line and the second hydraulic line to cause reciprocation of the working pistons. ### Claim 4 (depends on 1) The downhole hydraulic pump of claim 1 wherein the seal arrangement is a hydraulic sub. ### Claim 5 (depends on 1) The downhole hydraulic pump of claim 1 wherein the first working chamber and second chamber are pressure isolated from one another by seals disposed about the connecting rod. ### Claim 6 (depends on 1) The downhole hydraulic pump of claim 1 wherein the first hydraulic line, second hydraulic line, and the production tubing are non-coaxial. ### Claim 7 (depends on 1) The downhole hydraulic pump of claim 1 wherein at least one of the first and second hydraulic lines is concentric with and exterior to a production string. ### Claim 8 (depends on 1) The downhole hydraulic pump of claim 1 wherein one of the first or second hydraulic lines is defined at least in part by a casing of the well. ### Claim 9 (depends on 1) The downhole hydraulic pump of claim 1 wherein the first hydraulic line, second hydraulic line, and the production tubing are non-coaxial. ### Claim 10 A downhole hydraulic pump adapted to be disposed within a wellbore, the pump comprising: a first working piston having a first surface in contact with a power fluid and a second surface in contact with a wellbore fluid; a second working piston having a first surface in contact with a power fluid and a second surface in contact with a wellbore fluid; a connecting rod coupling the first working piston to the second piston; a first working chamber defined at least in part by the first surface of the first working piston; a second working chamber defined at least in part by the first surface of the second working piston; a seal arrangement respectively coupling a first hydraulic line from the surface to the first working chamber and a second hydraulic line from the surface to the second working chamber, wherein pressure applied via at least one of the first hydraulic line and the second hydraulic line causes reciprocation of the working pistons and wherein the first and second hydraulic lines are fluidically isolated from production tubing disposed in the wellbore and an annulus of the wellbore; and a flow path comprising one or more check valves wherein the one or more check valves are actuated by fluid pressure changes caused by reciprocation of the working pistons, thereby permitting wellbore fluid to be pumped to the surface. ### Claim 11 (depends on 10) The downhole hydraulic pump of claim 10 wherein the flow path is disposed within the connecting rod. ### Claim 12 (depends on 10) The downhole hydraulic pump of claim 10 wherein pressure is alternately applied via the first hydraulic line and the second hydraulic line to cause reciprocation of the working pistons. ### Claim 13 (depends on 10) The downhole hydraulic pump of claim 10 wherein the seal arrangement is a hydraulic sub. ### Claim 14 (depends on 10) The downhole hydraulic pump of claim 10 wherein the first working chamber and second chamber are pressure isolated from one another by seals disposed about the connecting rod. ### Claim 15 (depends on 10) The downhole hydraulic pump of claim 10 wherein the first hydraulic line, second hydraulic line, and the production tubing are non-coaxial. ### Claim 16 (depends on 10) The downhole hydraulic pump of claim 10 wherein at least one of the first and second hydraulic lines is concentric with and exterior to a production string. ### Claim 17 (depends on 10) The downhole hydraulic pump of claim 10 wherein one of the first or second hydraulic lines is defined at least in part by a casing of the well. ### Claim 18 (depends on 10) The downhole hydraulic pump of claim 10 wherein the first hydraulic line, second hydraulic line, and the production tubing are non-coaxial.