Patent ID: 8225873
Filing Date: 2012-07-24
Classification: E21B,F01C,F04C

Abstract:
1. An oil pump apparatus for pumping oil from an oil well having a wellhead, comprising: a) a well bore with a casing and a production tubing string having a production tubing bore and flow openings in the tubing string at a lower end portion of the tubing string; b) a tool body that is sized and shaped to be placed into the production tubing string bore of the oil well, wherein the tool body is not permanently attached to the casing or production tubing string, wherein the flow from the tubing string bore to a well annulus is enabled by the flow openings; c) a transverse portion dividing the tool body into upper and lower sections, the transverse portion being a seal that prevents fluid flow from the upper section to the lower section; d) a casing bore that surrounds the production tubing, the well annulus being an annular space in between the casing and the tubing string and surrounding the tubing string; e) a substantially incompressible working fluid that can be pumped into the production tubing bore; f) a prime mover for pumping the working fluid; g) a flow channel in the well bore that enables the working fluid to be circulated from the prime mover via the production tubing bore to the tool body at a location in the well and then back to the wellhead area via the flow openings and well annulus; h) a pumping mechanism on the tool body, the pumping mechanism including a first impeller contained within said upper section that is driven by the working fluid and a second impeller contained within said lower section that is mounted for rotation on a shaft with and is rotated by the first impeller, the second impeller pumping oil from the well via the tool body, wherein said first impeller comprises a pair of upper gears, each having longitudinally extending gear teeth that engage, and wherein said second impeller comprises a pair of lower gears, each having longitudinally extending gear teeth that engage, and each said upper gear rotating on a common shaft with a said lower gear; i) wherein the working fluid flows through gear teeth of the pair of upper gears to rotate the upper gears in different rotational directions and discharges from the tool body upper section above said transverse portion; j) wherein the tool body has flow conveying portions that discharge fluid from the tool body including a first flow conveying portion that discharges working fluid from the upper section and a second flow conveying portion that discharges oil from the lower section, thus enabling a mix of the working fluid and the oil as the oil is pumped by the pair of lower gears; k) wherein the pumping mechanism transmits the commingled fluid of oil and working fluid next to the tool body, enabling the commingled fluid to flow into the well annulus via the flow openings and then to the wellhead area; and l) wherein the shaft extends through the transverse portion and the shaft does not convey working fluid from the upper section to the lower section.