Niobrara & Codell Horizontal Well Completions: Lessons Learned Through Post-Stimulation Completion Diagnostics and How These Lessons Can Be Employed To Make Better Wells

Abstract

The optimistic outlook of the petroleum E&P industry, especially with regard to the re-balancing of oil and natural gas prices, has led to a renewed interest in tight gas and liquids-rich plays, more specifically in the Niobrara and Codell formations in the Denver-Julesburg (DJ) Basin. Through the use of post-stimulation completion diagnostics, insights have been obtained that can be utilized to optimize future hydraulic fracturing completions. Formations with less than one millidarcy permeability require reservoir stimulation in order to economically produce oil and gas. Engineers will often optimize a well's completion, spacing and hydraulic fracturing treatments to maximize its return with respect to cost. This paper will illustrate the use of post-stimulation completion diagnostics in identifying trends that are associated with effective completions in the Niobrara and Codell formations. In addition, case histories will be presented which illustrate methods that have increased the overall completion effectiveness in relation to proppant placement, wellbore deliverability and, ultimately, increased production performance. A horizontal well database (> 350 wells) was compiled to identify effective completion trends across the Niobrara and Codell formations. By employing proppant and fluid-based tracers, hydraulic fracture geometry, well deliverability and production performance were measured to identify trends that increased overall completion effectiveness. Primary completion results highlight areas including, but not limited to, effective proppant placement, full lateral production, frac stage length and containment, perforation cluster/sleeveefficiency, wellbore lateral length and inter-well communication between Niobrara and Codell formations. Many of the insights gained through this use of post-stimulation completion diagnostics in the Niobrara and Codell formations have led to increased completion optimization, production enhancements and field-wide cost reductions.