Modularized subsea seawater desalination system

A method exchanging a used subsea desalination module installed on a subsea desalination system, the method comprising:

• identifying that the used subsea desalination module requires service based on regular scheduled intervals or parameters selected from the group of parameters:
• desalinated water flow rate, water pressure drop over the subsea desalination module and desalinated water salinity;
• providing a vessel above the subsea desalination system;
• lowering a subsea desalination module lifting means onto the used subsea desalination module;
• securing the subsea desalination module lifting means to the used subsea desalination module;
• releasing subsea the used subsea desalination module from a subsea desalination template comprising a support frame including a lower surface and an upper surface forming at least one subsea desalination module zone defining a receptacle, and one or more anchors that extend from the lower surface of the support frame to penetrate into a seabed to anchor the subsea desalination template to the seabed whereby at least some of the weight of the subsea desalination template is supported by the one or more anchors;
• fluidically disconnecting subsea at least one subsea template fluid coupling of the used subsea desalination module from at least one module fluid coupling of the subsea desalination template;
• lifting the subsea desalination module lifting means and the used subsea desalination module on to the vessel;
• lowering the subsea desalination module lifting means and an exchange subsea desalination module whereby the exchange subsea desalination module is landed subsea at least partially within the receptacle defined by the at least one subsea desalination module zone of the subsea desalination template;
• securing the exchange subsea desalination module to the subsea desalination template;
• fluidically disconnecting subsea at least one subsea template fluid coupling of the used subsea desalination module from at least one module fluid coupling of the subsea desalination template;
• and
• releasing the subsea desalination module lifting means from the exchange subsea desalination module.

A subsea desalination system comprising:

• a seabed foundation comprising a template holding frame and one or more anchors that extend from the template holding frame to penetrate into a seabed to anchor the seabed foundation to the seabed whereby the one or more anchors support at least some of the weight of the seabed foundation;
• a subsea desalination template retrievably landable onto the template holding frame of the seabed foundation to releasably couple the subsea desalination template to the seabed foundation, and comprising a support frame including a lower surface landable on the template holding frame of the seabed foundation and an upper surface forming at least one subsea desalination module zone defining a receptacle, and at least one module fluid coupling and template piping in fluid connection with the at least one module fluid coupling;
• at least one retrievable subsea desalination module for desalinating seawater, the at least one retrievable subsea desalination module configured to be retrievably landed subsea at least partially within the receptacle of the at least one subsea desalination module zone of the subsea desalination template, the at least one retrievable subsea desalination module including a subsea template fluid coupling configured to be releasably connected subsea to the at least one module fluid coupling, and at least one reverse osmosis cartridge in subsea releasable fluid connection with the subsea template fluid coupling;
• at least one seawater circulation pump assembly in fluid connection with a seawater side of the at least one reverse osmosis cartridge;
• at least one desalinated water transport pump assembly retrievably connectable subsea to form a fluid connection with a desalinated water side of the at least one reverse osmosis cartridge in the at least one retrievable subsea desalination module and at least one desalinated water pipeline;
• at least one retrievable subsea water pump module including at least one of the at least one desalinated water transport pump assembly, and the at least one seawater circulation pump assembly;
• at least one template fluid coupling on the at least one retrievable subsea water pump module, configured to be connected to at least one module fluid coupling on a template with a pump module zone;
• and
• wherein the at least one desalinated water pipeline is configured to extend to a location above a sea level.