Submersible well fluid system
A submersible well fluid system for operating submerged in a body of water may include an electric machine and a fluid end. The electric machine includes a rotor and a stator residing in a first housing at specified conditions. The fluid end may include an impeller and be coupled to the electric machine. The submersible well fluid system may also include an adjustable speed drive for the electric machine in the housing. The submersible well fluid system may also include a chemical distribution system for supplying treatment chemicals to the submersible well fluid system, a barrier fluid supply system for supplying a barrier fluid to the submersible well fluid system, and a pressure management system.
1 . A submersible barrier fluid supply system for a submersible well fluid system for operating submerged in a body of water, comprising:
a submersible vessel configured to withstand ambient pressure of a surrounding environment about the submersible vessel, wherein the surrounding environment is the body of water;
a barrier fluid inlet fluidically coupled to the surrounding environment and configured to intake a barrier fluid from the surrounding environment;
a pump disposed within the submersible vessel and fluidically coupled to the barrier fluid inlet and configured to pump the barrier fluid to a passage disposed within the submersible vessel;
a filter disposed within the submersible vessel and fluidically coupled to the passage and adapted to filter the barrier fluid;
a barrier fluid outlet fluidically coupled to the filter;
a reject passage disposed within the submersible vessel and configured to fluidically couple the passage to the surrounding environment;
a reject valve disposed within the submersible vessel and configured to control flow of barrier fluid through the reject passage; and
an electric machine comprising an adjustable speed drive having an active power factor correcting front end that comprises an input power line filter and an active power factor correcting rectifier configured to switch at a frequency greater than 60 Hertz.
2 . The submersible barrier fluid supply system of claim 1 , comprising a housing internally defining a solids settling chamber exterior to and around the barrier fluid inlet, the housing comprising a water inlet adapted to intake water from the body of water into the solids settling chamber and settle solids at a first end of the solids settling chamber, wherein the barrier fluid inlet is arranged fluidically coupled to the solids settling chamber at a second end of the solids settling chamber opposite the first end.
3 . The submersible barrier fluid supply system of claim 2 , further comprising a membrane downstream of the filter, the membrane configured to further filter the barrier fluid.
4 . The submersible barrier fluid supply system of claim 3 , further comprising a second reject passage fluidically coupled to an upstream side of the membrane and configured to direct fluid that has not passed through the membrane to a solids settling chamber.
5 . The submersible barrier fluid supply system of claim 1 , where the filter comprises a multi-stage filter.
6 . The submersible barrier fluid supply system of claim 5 , where the multi-stage filter comprises a reverse osmosis membrane filter downstream from a coarse filter.
7 . The submersible barrier fluid supply system of claim 1 , comprising:
a first fluid circuit comprising the filter; and
a second fluid circuit, in fluidic parallel to the first fluid circuit, and comprising a second filter.
8 . The submersible barrier fluid supply system of claim 7 , where the first fluid circuit comprises the pump and the second fluid circuit comprises a second pump; and
where the submersible barrier fluid supply system comprises:
a first crossover passage fluidically coupling the first fluid circuit and the second fluid circuit downstream of the first and second pumps, between the first and second pumps and the filter and the second filter; and
a second crossover passage fluidically coupling the first fluid circuit and the second fluid circuit at a location downstream of the filter and the second filter.
9 . The submersible barrier fluid supply system of claim 7 , comprising a clean-out circuit comprising:
a bypass crossover passage fluidically coupling the first fluid circuit and the second fluid circuit downstream of the filter and the second filter, the bypass crossover passage configured to supply a back flush flow of fluid to the second filter; and
a third reject passage fluidically coupled to a passage between the barrier fluid inlet and the second filter to receive the back flush flow of barrier fluid from the second filter.
10 . The submersible barrier fluid supply system of claim 7 , comprising a clean-out circuit comprising:
a bypass fluidically coupling the first fluid circuit and the second fluid circuit downstream of the filter and the second filter, the bypass configured to supply a back flush flow of barrier fluid to one or both of the filter and the second filter; and
a second reject passage fluidically coupled to a second passage between the barrier fluid inlet and the second filter to receive the back flush flow of barrier fluid from the second filter.
11 . The submersible barrier fluid supply system of claim 1 , where the submersible barrier fluid supply system is configured to supply barrier fluid to one or more seals of a fluid end of the submersible well fluid system.
12 . The submersible barrier fluid supply system of claim 1 , where the barrier fluid outlet is in fluid communication with a bellows chamber, the bellows chamber comprising a bellows, and where the submersible barrier fluid supply system is configured to supply barrier fluid to the bellows chamber upon expansion of the bellows.