Abstract: A downhole tool, such as a logging-while-drilling tool, includes hydraulics that can provide real-time, automated control of the position of the downhole tool relative to a formation face. The positioning of the downhole tool is accomplished using processor-control of the hydraulics and using fluid present within the downhole tool, for example, mud from the downhole tool's mud bore. During operation the processor receives a signal that is indicative of the distance between the tool and a formation wall in the wellbore. The processor uses this information to position the downhole tool relative to the formation face by controlled injection of fluid into the annulus around the downhole tool. The reaction force from the pressure acts against the tool and pushes the downhole tool towards the opposite side where the annular pressure is lower.

Abstract: A downhole tool, such as a logging-while-drilling tool, includes hydraulics that can provide real-time, automated control of the position of the downhole tool relative to a formation face. The positioning of the downhole tool is accomplished using processor-control of the hydraulics and using fluid present within the downhole tool, for example, mud from the downhole tool's mud bore. During operation the processor receives a signal that is indicative of the distance between the tool and a formation wall in the wellbore. The processor uses this information to position the downhole tool relative to the formation face by controlled injection of fluid into the annulus around the downhole tool. The reaction force from the pressure acts against the tool and pushes the downhole tool towards the opposite side where the annular pressure is lower.