Niobrara Tight Oil Success in Colorado: What do the Numbers Indicate?
Chris Eisinger and James Milne
The Niobrara tight oil play continues to be an important hydrocarbon growth resource for Colorado. Since EOG's Jake well was drilled in September of 2009, more than 400 horizontal well starts targeting the Niobrara have been recorded by the state. While the majority of this activity has been in Weld County and the Denver Basin, horizontal Niobrara production has also been established in the Piceance, Sand Wash, and North Park Basins. At the end of 2011, at least 4.2 million barrels of Niobrara oil have reportedly been produced through horizontal drilling technology in Colorado. Decline rates in the Niobrara tight oil wells are an important indicator of the potential long term viability of these horizontal wells, but non-confidential data is limited and State-wide assessment challenging. Early indications suggest steep initial declines - a typical scenario for many tight unconventional oil plays. In the Niobrara horizontal fields of Weld county, stable production has been observed between 6 and 7 months after initial production. Production of 200 to 400 bbl/day is not uncommon for the stabilized rates currently. More data, becoming available in 2012 and early 2013, will help clarify the play's true decline nature and variability. Two years since the Jake well discovery and the ensuing Niobrara drilling boom, a simple look at horizontal well completion rates and distribution is useful in answering questions about the formation's production. Presented here will be an up-to-date analysis of overall Niobrara tight-oil production in Colorado and its estimated value to the economy using a combination of state and commercial-database resources. Emerging areas for horizontal Niobrara field development will be emphasized in this discussion. Detailed analysis of Niobrara drilling and production activity is valuable for assessing the early success and future potential of the play.
AAPG Search and Discovery Article #90156©2012 AAPG Rocky Mountain Section Meeting, Grand Junction, Colorado, 9-12 September 2012