of drilling can be implemented the relatively large mass of the drill collar section above the mpt 2 5 will greatly reduce acceleration up to the left during a high pressure pulse while acceleration of the bit 4 which has a relatively low mass down to the right will be significantly higher this method will be most useful when drilling horizontal wells where large weight on the drill bit is not available fig6 is a schematic view of mpmt 6 design of the mpmt 6 above the line 51 to the left can be identical to that of the mpt 2 3 as show in fig4 the design of mpmt 6 below the line 52 can be identical to the design of mpt 2 3 as shown in fig4 except that male thread 17 is replaced by female thread 53 into this female thread 53 is connected drill bit 4 piston shaft 10 b is not connected to spline shaft 53 while the pressure in cavities 21 b is higher than the pressure in 19 b the whole assembly comprising piston shaft 10 b and piston 9 b are lifted up to the left and spring stack 23 b is compressed when the pressure in cavities 21 b is lower than the pressure in cavities 19 b the stored mechanical energy in the disk springs stack 23 b forces multiple piston assembly 10 b and 9 b down to the right bottom part 53 of the multiple piston shaft 10 b acts as a hammer while seal nut 54 acts as an anvil seal nut is connected to the top end of spline mandrel 16 b by a threaded connection 55 this connection 55 may provide a.