Abstract: A method of selectively and variably positioning tubing within the generally horizontal section of a horizontally drilled well. A tubing string having a guide shoe secured to the end thereof is inserted into a portion of the horizontal section of a horizontal well. Smaller diameter tubing is then inserted through the tubing string and past guide shoe into the generally horizontal section. The smaller diameter tubing can be inserted to a point proximate the end of the horizontal section of the well or intermediate between the end and the guide shoe. The subterranean formation surrounding the generally horizontal section may be stimulated or treated by injecting a fluid via the smaller diameter tubing.