Abstract
Objectives/Scope

This presentation will summarize work conducted by the Energy & Environmental Research Center, in close coordination with the state of North Dakota and several Williston Basin oil and gas operating companies through a research program called the Bakken Production and Optimization Program (BPOP), and will cover 1) a review of the wells that have been refractured in the North Dakota portion of the Bakken petroleum system (BPS), 2) an evaluation of production performance of the refractured wells, 3) an assessment of refracturing economics, and 4) an assessment of the potential economic impact of a broad refracturing program applied throughout the BPS.

Methods/Procedures/Process

Production data for 272 refractured wells were compiled into a database. The production analysis of the wells quantified 1) pre- and postrefracture peak oil rates, 2) change in daily production data following the refracture operation, and 3) incremental estimated ultimate recoveries (EURs) (i.e., the change in EUR between pre- and postrefracture forecasts). The economic analysis focused on discounted net oil revenue, defined as the oil revenue after deducting royalties and state tax, and accounted for the refracturing cost. Economic outcomes were generated for each well using different input assumptions and then aggregated across all wells to estimate probabilistic outcomes. A decision tree modeling approach was used to evaluate the overall refracturing economic performance.

Results/Observations/Conclusions

The median outcome was $3.3MM, and the interquartile range from the 25th to 75th percentiles or the region within which half of the outcomes would be expected, was $0.6MM to $6.6MM. The large range highlights the variability in postrefracturing performance and the uncertainty in several input parameters. Sensitivity analysis showed that the net present value was sensitive to input assumptions for oil price and the probability of total production loss (i.e., no further production after refracturing). The results also showed different refracturing performance depending on the initial completion methods of the well prior to refracturing.

Applications/Significance/Novelty

The results showed that there is significant production potential of refracturing in the BPS, with oil revenues of several billion dollars depending on the candidate wells for additional stimulation, postrefracturing production performance, and other factors.

This content is only available via PDF.
You can access this article if you purchase or spend a download.