Abstract: A drill bit string has an internal steering module for measurement while drilling. A chassis is inserted into a modified drill collar from the axial end, rather than through the side. The chassis has external pockets machined into it from its outer diameter. The size of the longitudinally milled slots in the chassis is determined by the size of the components. The mud flow path is positioned off-center because of the component slots. The geometric shape of the flow path through the tool is shaped to optimize the flow area and maintain a wall thickness that can withstand the mud pressure. The wall thickness surrounding the flow area is proportional to the maximum hydrostatic pressure and the circulation pressure.

Abstract: A drill bit string has an internal steering module for measurement while drilling. A chassis is inserted into a modified drill collar from the axial end, rather than through the side. The chassis has external pockets machined into it from its outer diameter The size of the longitudinally milled slots in the chassis is determined by the size of the components. The mud flow path is positioned off-center because of the component slots. The geometric shape of the flow path through the tool is shaped to optimize the flow area and maintain a wall thickness that can withstand the mud pressure. The wall thickness surrounding the flow area is proportional to the maximum hydrostatic pressure and the circulation pressure.