Completions in the New Albany Shale

The New Albany Shale has been marginally attractive as a producer for many years, pre-dating most unconventional shale development efforts by a wide margin.
The first drilling attempts targeting New Albany Shale gas in Indiana occurred in 1885. A relatively large number of fields were drilled in the first half of the 20th century in all three Illinois Basin States.

Traditional completion and stim-ulation practice involved the use of gelatinated nitroglycerine charges and/or hydrochloric acid in open hole sections of vertical wellbores. The success of this process appeared to be related to the connection of the wellbore with naturally occurring open fractures.

Experimentation with water-based fracturing fluids began in the 1970s and led to a general consensus that techniques involving water were not fiscally viable.
This is possibly due to less-than-normal static pressure gradients and the propensity of water to adsorb on various clay-rich surfaces.

Nitrogen Fracturing

With the introduction of the nitrogen foam fracturing processes, it quickly became apparent that treatments with gaseous fluids were statistically out-performing near-wellbore treatments involving explosives and/or acid.

Vertical completions involving straight nitrogen (with no water or proppant) became popular, and slowly began to replace foam as a fluid of choice. Clearly, there are localized portions of NAS properties where 100 percent N2 treatments result in superior acceleration of reserve recovery, but there is not enough statistical data to indicate whether this type of stimulation fluid outperforms foam fracture treatments across wide swaths of the play.

The gradual acceptance of horizontal drilling and multistage completions led to the realization that these improvements generally resulted in higher reserve recovery efficiency per D&C dollar compared to vertical drill wells.

Though a number of operators still work with vertical completions, the preponderance of clearly commercial completions have been associated with horizontal wellbores within a wide range of gaseous commodity prices.

Verifiable success with slickwater in the Ft. Worth Basin Barnett and other horizontal plays was followed by renewed speculation and a short resurgence of experimentation with large volumes of slickwater in the New Albany Shale.

To date, no known successes involving slickwater completions in this formation have been reported in the literature or in public data.