Method and system for ultra-deep borehole geothermal energy harvesting

A multivessel system comprising a plurality of pressure vessels for installing a production train in an ultra-deep borehole into the Earth's lithosphere, the system comprising:

• a plurality of gate valves, each gate valve being configured to provide a hermetic seal between at least two spaces;
• a first pressure vessel comprising a first vessel upstream opening configured to receive a train section through a first one of said plurality of gate valves and a first vessel elevator configured to engage and hold the train section as the first vessel elevator moves in the first pressure vessel along a portion of a length of a train channel, the first pressure vessel further comprising a first vessel downstream opening;
• a second pressure vessel comprising a second vessel upstream opening configured to receive the train section from the first vessel downstream opening through a second one of said plurality of gate valves and a second vessel elevator configured to engage and hold the train section as the second vessel elevator moves in the second pressure vessel along another portion of the length of the train channel, the second pressure vessel further comprising a second vessel downstream opening;
• and
• a train clamp configured to engage and hold the production train in the borehole,
• wherein each of said first vessel elevator and said second vessel elevator includes a clamp configured to engage and hold the train section as the respective first vessel elevator or the second vessel elevator moves along the train channel.

A method for installing a production train in an ultra-deep borehole into the Earth's lithosphere, the method comprising:

• depressurizing a first pressure vessel having a first vessel upstream opening, a train channel, and a first vessel downstream opening;
• opening a first gate valve to provide access to the first vessel upstream opening;
• inserting a train section through the first vessel upstream opening into the first pressure vessel;
• clamping and holding, by one of a plurality of elevators equipped with a clamp, the train section in the first pressure vessel;
• closing the first gate valve and pressurizing the first pressure vessel;
• opening a second gate valve located downstream of the first vessel downstream opening;
• clamping and lowering, by activating movement of another one of the plurality of elevators, the train section into a second pressure vessel;
• closing the second gate valve and depressurizing the first pressure vessel;
• moving said another one of the plurality of elevators downward until the train section contacts or is within a predetermined distance of an upstream end of a production train equipped at a downstream end with a production train base;
• connecting, by a robot, the train section to the upstream end of the production train;
• and
• lowering the production train into a borehole while inserting another train section into the first pressure vessel.