Patent ID: 11920440
Assignee: RENEWELL ENERGY
Field: Civil engineering (Other fields)
Classification: CPC E  F  H  Y | IPC E  F  H

Claim 7:
8. A potential energy conversion system comprising:
a movable mass suspended by a line in a non-producing well having an upper section and a lower section that are separated from each other by a plug, the upper section being at least partially filled with a fluid, and the movable mass being movable within the fluid in the upper section between the plug and a wellhead located at the earth's surface;
wherein the fluid comprises an additive, and the additive is selected to minimize corrosion, modify rheological properties, reduce friction, convey biocidal activity, or inhibit scale; and
wherein the line is coupled to a motor operable to lift the movable mass and a generator operable to produce electricity when lowering the movable mass within the upper section.