upwardly at whatever angle it is bent although it is envisioned that the direction of the rotary drillstring could be controlled on a continuous basis the presently preferred embodiment contemplates making heading corrections approximately every twenty feet further although the present invention is contemplated for use with an otherwise conventional oil well drawworks system a modified embodiment tends to reduce to some extent the aforementioned considerations directed to the phase shift between the initiation of a pulse on the drill bit and due to the time required for wave propagation and wind up in the drillstring such a modified embodiment uses a hydraulic cylinder arrangement below the hook from which the drillstring extends the hydraulic cylinder arrangement is then used to pulse the bit weight while the drawworks controls the overall bit weight u s pat no 4 535 972 to keith k millheim and tom m warren and u s pat no 4 660 656 to tommy m warren warren j winters and j ford brett disclose such a hydraulic cylinder arrangement in a drilling rig in this embodiment the response time which otherwise would be needed from brake to drum to block for transmitting a pulse on the drill bit would be eliminated thereby eliminating any unreliability in the consistency e g of that segment of the delay in response contributing to the aforementioned phase shift.