TOTAL DOWNSTROKE FRICTION FROM DOWNHOLE DYNAMOMETER ANALYSIS
Scott Long, Flexbar Inc. & Elton Smith, Kirk Mehaffey, & Albert Garza, Pioneer Natural Resources Inc.
The Oil and Gas Industry is benefiting from development and use of improved predictive computer programs that now utilize several friction defaults. These predictive programs are more capable of predicting surface and downhole rod pumping conditions. The need for improved predictive accuracy is requiring program users to adopt improved estimates of downstroke friction to model downhole pumping conditions. Lack of improved estimates of downstroke friction has resulted in program users accepting and designing with current friction defaults that may result in results different than actual downhole pumping conditions. This paper develops a method of estimating total downstroke friction from existing dynamometer analysis. Use of this method in producing fields with similar operating conditions will provide improved estimates of total downstroke friction. A better understanding of the magnitude of total downstroke friction will result in improved friction defaults. Improved friction defaults will result in more effective designs of rodstrings and artificial lift systems.