The Haynesville organic shale has just under 3600 wells, completed before mid-2016, with cluster spacings over 50 feet. This wide spacing resulted in many wells having missed or bypassed reserve recovery due to inefficient completions. Understandably these wells would be prime candidates for refracturing. Refracs have the advantage of lower up-front capital cost, fewer operational issues that rely on functioning supply chains, and significantly lower carbon footprint than new wells that need to be drilled prior to completion. However, a frequent concern is that refracs in the Haynesville cannot compete with new well economics. We looked at both public and operator refrac data to identify the criteria that makes a good Haynesville refrac candidate. We offer case studies to show the economic performance of 45 Haynesville liner refracs using actual post refrac decline data and current well costs. Both the economic value of the post refrac production is included along with the economic value of protecting infill wells from asymmetric fractures. An analysis of the completion design for a typical Haynesville refrac is also provided to demonstrate that significant upside remains for improvement if "best practices" are applied. These include Extreme Limited Entry (XLE), zero-degree top perforations per cluster, larger diameter expandable liners, and microproppant in the prepad.
In our data set, the typical Haynesville refrac completion has very low pressure drops (520 psi pre-erosion) across the perforations. With average treating pressures of 9500 psi there is limited room for higher pressure drops due to a 10,500-psi surface pressure limit. And so, the available delta pressure for treatment is limited to +/- 500 psi when a 2500 to 3000 psi pressure drop is recommended to maximize cluster efficiency (Hausveit 2020). With the author’s recommended practices, over 2500 psi of excess friction losses can be avoided, providing adequate margin to achieve the recommended pressure drop. With increased cluster efficiency, increased recovery factors should follow. While Haynesville refracs have successfully increased estimated ultimate recovery (EUR), when "best practices" are followed, the economic returns should be highly competitive with new-well completion economics. If the refracs had the 60% average cluster efficiency values from several studies done on poorly diverted treatments (Weddle 2018 and Miller 2011) the total NPV10 for a P50 refrac is equivalent to the new well NPV10 values.