The tractor is a kind of tool to convey the downhole tools in the horizontal well and highly deviated well. When logging in the horizontal well and highly deviated well, if the downhole tools couldn’t down to the destination well section by its gravity, the tractor can convey the downhole tools to the right position by its power unit. Compare with the drill pipes transportation, it can save logging time, lighten the working strength of homework and reduce the risk of construction. And no need well derrick, can convey greater distance compare with the continuous pipeline transportation and with no influence by the well depth.

Tractor in the horizontal casing well has small diameter, serving as a dragging device when the logging tools go through the oil tube in the horizontal well. Instead of a drill pipe, it sends the logging equipment to the destination formation relying on its traction to complete the logging jobs. It saves cost and time.

Segment cement bond logging tool is applied to measure the quality of cement bonding around a cased hole both in vertical and horizontal directions, showing the cement bonding quality at casing-to-cement interface(the first interface) in a grey level plot, and evaluating the cement bonding quality at cement to formation interface(the second interface).

It measures three-axis accelerated velocity, three-axis angular, temperature etc., acquiring the parameters such as well deviation, azimuth, tool face etc. via the DSP calculation, There are two kinds, flexible gyroscope and fiber-optic gyroscope.