Abstract: A control system for use in controlling actuation of tools in a subterranean well. In a described embodiment, a control system includes a well tool, an actuator for the well tool and a control module interconnected between the actuator and first and second fluid lines. The control module is operative to meter a predetermined volume of fluid from the actuator to the second line in response to pressure applied to the first line.

Abstract: A downhole tractor is provided that includes a housing and a first wheel assembly coupled to the housing that is operable to translate away from the housing in a first direction. The first wheel assembly has a first electric motor, a first wheel, and a first reduction gear assembly coupled between the first electric motor and the first wheel. A second wheel assembly is coupled to the housing and is operable to translate away from the housing in a second direction that is opposite to the first direction. The second wheel assembly has a second electric motor, a second wheel, and a second reduction gear assembly coupled between the second electric motor and the second wheel. A fluid ram is coupled to the first and second wheel assemblies for selectively translating the first and second wheel assemblies toward and away from the housing. A first controller is provided for controlling the flow of current to the first and second electric motors.

Abstract: A system for transmitting hydraulic control signals and hydraulic power to downhole well tools while reducing the number of hydraulic lines installed in the wellbore. Hydraulic control signals can be furnished at relatively lower pressures, and the hydraulic pressure within the line can be selectively increased over a threshold level to provide hydraulic actuation power. The system can provide multiple control paths through a few number of hydraulic lines to provide flexibility and verification of well tool operation. Closed loop hydraulic operation monitors well tool operation, and a combination of pressurized hydraulic lines can provide an operating code for selective downhole well tool control. Four hydraulic lines can provide independent control and actuation of seven well tools, and additional combinations can be constructed.