Patent attributes
A bottom hole assembly for drilling a cavity including a chassis configured to rotate is provided. The chassis may include a conduit, a circuit, a pressure transfer device, a plurality of pistons, a plurality of valves, and a plurality of cutters. The conduit may accept a first flow of a primary fluid. The circuit may have a second flow of a secondary fluid. The pressure transfer device may be configured to transfer pressure between the flows. The pistons may be operably coupled with the circuit, and each piston may be configured to move based at least in part on a pressure of the circuit at that piston, with the valves possibly configured to control a pressure of the circuit at each piston. Each cutter may be coupled with one of the pistons.
