A wellbore reamer tool for use in downhole oil well operations includes two helical impellers, two cutting portions, and an integral blade stabilizer. The first helical impeller is positioned at a downhole end for cleaning the wellbore of formation cuttings in advance of reaming by the cutting portions, and directing the formation cuttings to a desired position on the first cutting portions. The first and second cutting portions include radially insertable cutter inserts having cutters for reaming the wellbore to yield the formation cuttings. An integral blade stabilizer is positioned between the cutting portions for supporting the tool while driving uphole flow of the formation cuttings. A second helical impeller is positioned above the second cutting portions for cleaning the wellbore and boosting newly incorporated formations cuttings uphole towards surface.