string 200 is pumped propelled downwards by the fluid pressure that is pushing behind the tool string 200 the cable 111 is spooled out at the surface by the truck 115 a cable tension sensing device 117 is located at the surface and provides cable tension data to control track 115 a speed sensor device 119 located at the surface provides surface cable speed data to control track 115 in some implementations the tool string will have sufficient weight that gravity will convey the tool string down the wellbore without the assistance of pump fluid pressure fig7 a is a side view of an exemplary logging tool string 200 a and 200 b applicable to the operations of a general tool string 200 illustrated in fig1 to 6 in some implementations the tool string 200 may be implemented and tool string 200 a as illustrated in fig7 a and include various data logging instruments used for data acquisition for example a casing collar locator 220 a telemetry gamma ray tool 231 a density neutron logging tool 241 a borehole sonic array logging tool 243 a compensated true resistivity tool array 251 among others as are well known in the art the tool string is securely connected with the cable 111 by cable head tool 211 the tool string may include a downhole tension sensing device 213 and a downhole speed sensing device such as an accelerometer 215 as the tool string 200 is propelled down the bore of the drill string by the fluid.