Paper: Reduced Tubing Failures In Rod-Pumped Wells Utilizing Downhole Caliper Surveys

The downhole tubing caliper survey, as part of a preventative maintenance program, is an effective tool for reducing the number of future or repeat tubing failures that occur on rod-pumped wells. Preliminary field results of an investigation in the North McElroy Unit, Crane and Upton Counties, Texas indicate that downhole tubing caliper surveys may be the most economical and effective field method of eliminating worn or severely corroded tubing in a well and insuring against troublesome repeat tubing failures. Generally, common practice is to replace only the failed joint and any visually defective tubing until a certain frequency of failures occur, although hydrostatic testing is sometimes utilized as a means of detecting thin-walled joints. This presentation compares common field practices to the downhole tubing caliper survey, from the standpoints of both economics and relative repeat failure frequency. The caliper survey's potential as a monitor of corrosion, wear, and downhole mechanical problems is also discussed.