esp 13 is driven by a downhole motor 15 which is a large three phase ac motor motor 15 receives power from a power source not shown via power cable 17 motor 15 is filled with a dielectric lubricant a seal section 19 separates motor 15 from esp 13 for equalizing internal pressure of lubricant within the motor to that of the well bore a gas separator 21 for at least partially removing gas from the well fluid is installed on a pump intake portion of esp 13 additional components may be included such as a sand separator and a pressure and temperature measuring module large esp assemblies may exceed 100 feet in length an upper end of esp 13 couples to a production string 23 a rotating shaft 25 may extend from motor 15 up through seal section 19 gas separator 21 and esp 13 motor 15 may rotate shaft 25 to in turn rotate impellers 27 within esp 13 a person skilled in the art will understand that shaft 25 may comprise multiple shafts configured to rotate in response to rotation of the adjacent upstream coupled shaft impellers 27 will generally operate to lift fluid within esp 13 and move the fluid up production string 23 impellers 27 perform this function by drawing fluid into a center of each impeller 27 near shaft 25 and accelerating the fluid radially outward generally the fluid accelerated by each impeller 27 will then flow into a diffuser 29 axially above impeller 27 there the fluid is directed from a radially outward position.