An apparatus for positioning a tool, such as a perforating gun, in a wellbore to orient the tool in a desired direction. An anchor having a first reference terminal is set in the wellbore, the first reference terminal pointing in a known direction. A second reference terminal is attached to the tool, the second reference terminal being coupled to the first reference terminal to orient the tool in the desired direction. A gyroscope measures the direction of the first reference terminal with respect to the magnetic north. The perforating gun includes charges arranged to perform perforating along a preferred fracture plane, such as 0.degree.- or 180.degree.-phased perforating.