While various mathematical models exist for predicting downhole forces and motion in sucker rod type pumping systems, none have been thoroughly verified with actual measurements. In fact, downhole force measurements were last made in 1942.

This report documents the development and use of a down hole data acquisition system designed and built to dynamically measure force and displacement at the bottom of the hole.

The system consists of a microcomputer, memory storage, power supply, and transducers, designed to fit collectively in a volume slightly over one inch in diameter by five feet in length.

Downhole dynagraphs and other data recovered from over one mile in the ground are presented.