A Study of the Permanence of Production Increases Due to Hydraulic Fracture Treatments

Abstract

In order to evaluate the ability of a Hydrafrac treatment to effect asustained increase in well production, data were accumulated on the first 65wells in 26 fields treated by Stanolind. Since these data were obtained fromsuch a large number of fields, it is felt that individual well or reservoircharacteristics do not affect the overall picture, as might be the case if thestudy were made in one field or one group of wells in a field. These data aretabulated in Table I and plotted on Figs. 1 and 2. An analysis of Fig. 1 shows that at the end of six months, 75 per cent, or45, of 60 wells on which data were available showed a sustained productionincrease. At the end of two years, data were available on 25 wells. Of these,15 wells, or 60 per cent, showed a sustained production increase. At the end ofthree years, 55 per cent, or 10, of 18 wells had a production rate greater atthat time than before Hydrafrac treatment. The lack of information onadditional wells at the end of the third year is primarily a result of thesmall number of treatments conducted in the early stages of field applicationof this process. Production data on wells treated more than three years ago arelimited to so few wells that they were not considered. Fig. 2 contains two plots of the production data from the wells surveyed, expressed as per cent of pretreatment production plotted against time in yearsafter treatment. Only the wells showing a sustained increase in production wereconsidered in the upper plot, while all wells on which data were available wereconsidered in the lower plot. The upper curve shows that two years aftertreatment, the production from these wells was 200 per cent greater than beforetreatment. Even after three years, these wells were producing at a rate thatwas 134 per cent of the pre-Hydrafrac production rate. When considering all ofthe wells treated from which data were available, it may be seen from the lowercurve that after two years over 150 per cent of pre-Hydrafrac production wasbeing maintained. The production from these wells did not decline to thepretreatment level until approximately two and three-fourths years aftertreatment. The increased production shown on Fig. 2 is all net increased production, since the cost of Hydrafrac treatment of all wells was paid out during thefirst six months of production not shown on this graph. T.N. 108