Patent ID: 9255474
Filing Date: 2016-02-09
CPC Classification: E21B

Claim Text:
1. An apparatus for pumping a downhole fluid, the apparatus comprising: a carrier configured to be conveyed through a borehole penetrating an earth formation; a fluid extraction device disposed at the carrier and configured to extract a sample of formation fluid from the earth formation and dispose the sample in a fluid probe cell and a sample tank; a pump disposed at the carrier and configured to pump the sample from the formation and into the fluid probe cell and the sample tank; a multi-phase electric motor coupled to the pump and configured to receive multi-phase electrical energy from a power source in order to operate the pump, the multi-phase electrical motor comprising multiple windings; a switch configured to connect the multiple windings in a configuration selected from a plurality of configurations comprising (i) a first configuration where one terminal of each winding of the multiple windings is uniquely connected to one terminal of another winding and (ii) a second configuration where one terminal of each winding of the multiple windings is commonly connected to one terminal of each of the other windings; a controller configured to operate the switch to select the first configuration or the second configuration based on a load analysis; and a sensor configured to sense a downhole parameter of a pumping process using the pump and to provide the sensed parameter as input to the controller, the sensed parameter comprising pump differential pressure, pump flow rate, or sample tank pressure, wherein the load analysis is based on the sensed parameter.