A subsea process fluid lubricated water injection pumping system (200, 300, 400, 500, 600) comprising: an elongated impeller shaft (206, 306, 406, 506, 606); an electric motor (210, 310, 410, 510, 610, 670) configured to impart torque on the impeller shaft (206, 306, 406, 506, 606) thereby causing the impeller shaft (206, 306, 406, 506, 606) to rotate about a main longitudinal axis in a drive direction, wherein the electric motor (210, 310, 410, 510, 610, 670) includes a rotor (212, 612, 672) and a stator (214, 614, 674); a first set of impellers (224, 324, 424, 524) fixedly mounted to the impeller shaft (206, 306, 406, 506, 606) and configured to increase pressure of a single phase aqueous process fluid when the impeller shaft(206, 306, 406, 506, 606) is rotated in the drive direction thereby imparting a first axial force on the impeller shaft (206, 306, 406, 506, 606) in a first direction parallel to the longitudinal axis; a second set of impellers (234, 334, 434, 534) fixedly mounted to the impeller shaft (206, 306, 406, 506, 606) and configured to increase pressure of the single phase aqueous process fluid when the impeller shaft (206, 306, 406, 506, 606) is rotated in the drive direction thereby imparting a second axial force on the impeller shaft (206, 306, 406, 506, 606) in a second direction opposite to the first directior and at least one bearing surface (228, 238, 328, 336, 428, 438, 439, 528, 538, 539, 626, 628, 638, 639, 690) configured to allow the impeller shaft (206, 306, 406, 506, 606) to rotate about the longitudinal axis; characterized by a bushing (218, 318, 418, 518, 618, 680) with a small gap, arranged around the impeller shaft (206, 306, 406, 506, 606) and for restricting a rate of a leakage through a gap separating the rotor (212, 612, 672) and the stator (214, 614, 674) of the electrical motor (210, 310, 410, 510, 610, 670), and wherein the at least one bearing surface (228, 238, 328, 336, 428, 438, 439, 528, 538, 539, 626, 628, 638, 639, 690) is further configured for lubrication and cooling from the process fluid via said leakage. an elongated impeller shaft (206, 306, 406, 506, 606); an electric motor (210, 310, 410, 510, 610, 670) configured to impart torque on the impeller shaft (206, 306, 406, 506, 606) thereby causing the impeller shaft (206, 306, 406, 506, 606) to rotate about a main longitudinal axis in a drive direction, wherein the electric motor (210, 310, 410, 510, 610, 670) includes a rotor (212, 612, 672) and a stator (214, 614, 674); a first set of impellers (224, 324, 424, 524) fixedly mounted to the impeller shaft (206, 306, 406, 506, 606) and configured to increase pressure of a single phase aqueous process fluid when the impeller shaft(206, 306, 406, 506, 606) is rotated in the drive direction thereby imparting a first axial force on the impeller shaft (206, 306, 406, 506, 606) in a first direction parallel to the longitudinal axis; a second set of impellers (234, 334, 434, 534) fixedly mounted to the impeller shaft (206, 306, 406, 506, 606) and configured to increase pressure of the single phase aqueous process fluid when the impeller shaft (206, 306, 406, 506, 606) is rotated in the drive direction thereby imparting a second axial force on the impeller shaft (206, 306, 406, 506, 606) in a second direction opposite to the first directior and at least one bearing surface (228, 238, 328, 336, 428, 438, 439, 528, 538, 539, 626, 628, 638, 639, 690) configured to allow the impeller shaft (206, 306, 406, 506, 606) to rotate about the longitudinal axis; characterized by a bushing (218, 318, 418, 518, 618, 680) with a small gap, arranged around the impeller shaft (206, 306, 406, 506, 606) and for restricting a rate of a leakage through a gap separating the rotor (212, 612, 672) and the stator (214, 614, 674) of the electrical motor (210, 310, 410, 510, 610, 670), and wherein the at least one bearing surface (228, 238, 328, 336, 428, 438, 439, 528, 538, 539, 626, 628, 638, 639, 690) is further configured for lubrication and cooling from the process fluid via said leakage.