The principle components of Weatherford’s multistage centrifugal pumps are nickel-alloyed iron stages that consist of rotating impellers and stationary diffusers. Depending on desired rates and performance, this corrosion-resistant stage construction are offered as either floater or compression style. Our compression style pumps can cover a broad range of desired flowrates, as they can absorb greater downthrust by transferring the forces downward through the pump to the motor seal thrust bearing, as opposed to floater construction, where the thrust is absorbed by the pump stages themselves.

The stage geometry for all Weatherford's pumps is either radial- or mixed-flow. Typically, the radial-flow type is more efficient at flow rates lower than 2,500 BPD. Mixed-flow stages are more efficient at higher flow rates, and also offer improved gas handling characteristics. (See our Gas Separator section for high efficiency gas handling equipment). Selecting the correct number of stages will provide the required lift or head for the application, and the size of each stage will determine the volume of fluid through the pump. Weatherford specify a recommend ed operating range (ROR) for all pumps. It is important to operate the pump within this range to ensure optimum efficiency and increased run-life.

Additional features of Weatherford’s ESP pumps include:

• Stages mounted on nickelcopper super-alloy shaft for high inherent yield strength. Main housing material comprised of a low-carbon steel. Head and base made from medium-carbon steel and also house abrasion-resistant TuC bearings to prevent radial wear and vibration; for corrosive applications stainless steel housings can be provided, or carbon steel housings can be ‘flame-sprayed’ with a monel coating if preferred
• For abrasive (sandy) conditions, abrasion-resistant tungsten carbide bearings can be used throughout the pump to maintain radial stability
• Higher-strength shafts are available for cases where the number of stages and load on the shaft could cause the shaft to deform or even break under normal operating conditions
• All Weath erford pumps built to ISO 9001:2000 standard and are tested to API-RP-11S2

As with all of our ESP components, we will only specify equipment specifically designed to handle the well conditions. For example, if the pump HP requirements are higher than normal we will specify a higher strength shaft material. Please see Weatherford pump brochure for details of available configurations.