Rotary tool hydraulic power system

A downhole well tool, comprising:

• a hydraulic power system, comprising:
• an oil compensator configured to deliver a borehole pressure to a compensated hydraulic fluid;
• a hydraulic pump module including an inlet fluidly coupled to an outlet of the oil compensator, the hydraulic pump module configured to pressurize the compensated hydraulic fluid for delivery as a pressurized compensated hydraulic fluid at an outlet of the hydraulic pump module;
• and
• a hydraulic control module including a first inlet fluidly coupled to the outlet of the oil compensator, a second inlet fluidly coupled to the outlet of the hydraulic pump module, and an outlet fluidly coupled to a rotary milling module, wherein the hydraulic control module is operable between a first state and a second state, the hydraulic control module routing the compensated hydraulic fluid from the outlet of the oil compensator to the rotary milling module in the first state, and the hydraulic control module routing the pressurized compensated hydraulic fluid from the outlet of the hydraulic pump module to the rotary milling module in the second state.

A method, comprising:

• delivering a borehole pressure to a compensated hydraulic fluid with an oil compensator of a hydraulic power system of a downhole well tool;
• delivering the compensated hydraulic fluid from an outlet of the oil compensator to an inlet of a hydraulic pump module of the hydraulic power system the downhole well tool;
• delivering the compensated hydraulic fluid from the outlet of the oil compensator to a first inlet of a hydraulic control module;
• pressurizing the compensated hydraulic fluid received at the inlet of the hydraulic pump module with the hydraulic pump module for delivery as a pressurized compensated hydraulic fluid;
• delivering the pressurized compensated hydraulic fluid from an outlet of the hydraulic pump module to a second inlet of the hydraulic control module;
• and
• operating the hydraulic control module between a first state and a second state, the hydraulic control module routing the compensated hydraulic fluid from the outlet of the oil compensator to a rotary milling module in the first state and the hydraulic control module routing the pressurized compensated hydraulic fluid from the outlet of the hydraulic pump module to the rotary milling module in the second state.