The Technology of Artificial lift Methods 3a is the first volume in a series of two which consists of gradient curves for vertical multiphase tubing flow and horizontal multiphase pipe flow. Tubing sizes from 1in. through 12 in. are included with rates commensurate with each size. Curves for 10%,50%, and 100% oil have been prepared for each flow rate Horizontal pipes from 2-in. ID to 12-in ID are included with rates commensurate for each pipe size. Curves for 100%oil and 100% water have been prepared for each flow rate.