structural features geometries and materials as known in the art to utilize the pressure of well fluid 68 in combination with the stretch and retraction properties of protector bag 64 to positively pressurize motor fluid 54 initially motor fluid 54 is injected into motor 14 and protector bag 64 is pressurized until a desired positive pressure is obtained within motor 14 for example oilfield assembly 10 may set an initial pressure such as 25 100 psi prior to submerging into the well an exterior chamber 70 adjacent protector bag 64 also may be filled with fluid prior to submerging the system into the well well fluid 68 enters housing 38 through ports 72 and mixes with this fluid in exterior chamber 70 as oilfield assembly 10 is submersed into the well protector bag 64 also may have various protection elements to extend its life and to ensure continuous protection of motor 14 for example a filter 74 may be disposed between ports 72 and exterior chamber 70 of protector bag 64 to filter out undesirable fluid elements and particulates in well fluid 68 prior to fluid communication with exterior chamber 70 a filter 76 also may be provided adjacent interior 66 of protector bag 64 to filter out motor shavings and particulates as illustrated filter.