Since the discovery of the horizontal EOG JAKE 2-01H well with an initial production (IP) of approximately 1500 barrels of oil a day, multiple operators have been trying to reproduce the same results on their Niobrara acreage with their own horizontal wells. This well has sparked the land rush for mineral acres across all of the DJ basin from Wyoming to southern Colorado.
The questions for each operator are the same:
- What will the initial production be?
- Where and when will the inevitable decline curve flatten out?
Data available for analysis is sparse since most of the horizontal wells that have been drilled by competitors have been completed in 2010 and the production data is still being held confidential by the COGCC for 6 months. These are what is known in the industry as tight holes. More confidential data should begin coming available between December 2011 and March 2012, but production curves for these wells will not be apparent for another year or so.
An extensive search at the COGCC has turned up a few early horizontal wells that that have yielded some data that show a play at a stage where operators are trying to figure out how to make the Niobrara produce. Note: Only horizontal wells were included in the study as this is the only acknowledged technology with which to effectively yield large amounts of oil from this play.
Niobrara News has constructed a chart with available data from the COGCC showing the decline curve of the famous JAKE well along with a number of other horizontal wells completed by EOG Resources, Noble Energy, and Kerr-McGee (a subsidiary of Anadarko) The figures reported are for barrels of oil produced. Gas is not included in these figures so a BOE figure is not computed.
An analysis of the chart shows that the JAKE well has plateaued nicely at around 200 bbl/day from its lofty 1500 bbl/day. The well appears to have reached its stable production around 7 months after IP. When compared to the other wells on the graph, a 6 to 7 month decline curve stabilization period appears to be common on most of the horizontal Niobrara wells, if one projects their decline curves forward.
The other striking feature on the graph are the results from some of the other wells that are no doubt disappointing for the cost of a horizontal well such as Noble 70 Ranch USX BB 09-99HZ. On the other hand, the decline curve of Kerr-McGee DOLPH 27-1HZX, appears to be smooth, stable, and predictable and is sufficiently productive to warrant the search for more wells just like it.
Additional data points not included in the decline curve graph are available from EOG in its Investor Presentation for Sep 2011. The presentation included data from a few of its wells that are still tight holes. It is suggested that these are stabilized production rates.
- Fiscus Mesa 9-10H – 335 bbl/day
- Gravel Draw 9-09H – 277 bbl/day
The conclusion from this little study clearly shows that more data is needed to characterize Niobrara production. It shows operators in the midst of engineering experimentation to find out which engineering techniques work, which do not, and equally important, where the oil sweet spots lie. Until more data becomes available around the beginning of 2013, the “typical” Niobrara decline curve will have to remain a guessing game based on operator and location.