In unconventional plays, comparing the effect of different completion designs or well-management strategies on well performance remains a challenge because of the relatively brief production history and lack of long-term field analogs of these plays. This study examines various production durations as potential candidates for reliable indicators of well quality. The results show that predictions of midterm performance begin to be reliable only near 180 days of cumulative well production. This study used actual daily production data to confirm that 30- and 90-day initial production are not correlated strongly to well actual performance in the 2-year range.

Introduction

It has been a common practice to quantify performance of unconventional wells through their 30-day initial production for purposes of information for the media and in investor presentations. The authors’ experience has been that the 30-day initial production often does not necessarily quantify a well’s potential. The goal of this study is to compare various production-duration periods to identify which can most accurately forecast longer-term production. This study tests different production durations by use of actual well-production history from the Utica play in Ohio, USA. The term “IP-nnn” in the paper refers to a specific number of days of nonzero production for the well; for example, “wellhead gas IP-30” refers to the total volume of the first 30 days of nonzero wellhead gas production for the well, whereas “condensate IP-90” refers to the total volume of the first 90 days of nonzero condensate production for the well.