Recovering the sometime significant reserves left behind in under-stimulated unconventional wells requires refracturing utilizing modern frac designs. While the primary driver for any refracturing work is to boost base production and unlock stranded reserves with low capital investment, success depends on the isolation of existing perforations.
background
Coretrax was contacted by independent energy company, Crestone Peak Resources to determine if it was possible to replicate the performance of a vertical refrac, in a mature, horizontal well. This would drastically increase the life of the field by rejuvenating wells that were underperforming due to non-optimal completion designs and mechanical issues experienced during the well life.
Solution – Optimal Stimulation, Minimal Interruption
As production from this well is depleted, with only 3bbls/day being produced - an expandable liner with plug and perf was selected as the most suitable method for a slick-water frac and was deployed to the operator’s Greater Wattenberg Field of the Denver-Julesburg (DJ) Basin to support.
The solution consisted of 7,253ft of our 3.500”x 0.254” wall ReLine MNS expandable solution, that would be set within 4.500” 13.5# casing to cover pre-existing perforations and allow for selective restimulation of well.
Designed for deployment on jointed pipe, the cased hole system can cover long or short intervals from 30ft – 8,000ft. It can be configured to expand and seal across various ID restrictions in the wellbore such as nipples or frac sleeves. It provides a single trip solution with no shoe milling to clad and isolate various wellbore integrity concerns with minimal loss of inner diameter (ID), whilst providing high burst and collapse ratings.
Unlike other expandable systems, the running tool configuration allows the liner to be expanded in multiple load conditions. It can be left at a neutral position before anchoring the top seal and exiting the liners with the inner string, which is critical for reliability in severe fracturing downhole environments.
Results – Improved Production, Continued Rejuvenation
Post the successful rejuvenation of the 1st well, Coretrax were then contracted to conduct further ReLine MNS activity with the Colorado-based producer to refrac another infill pad (two parent wells and 11 child wells). By refracing multiple wells simultaneously, the operator sought to restimulate the existing pads whilst providing increased reservoir pressure to assure production from new infill producers. Initial results show increased significant uplift in production from all wells on the pad.
Crestone has set a total of five long casing patches, ranging from 2,500ft to 7,200ft, on wells initially completed as both sliding sleeve and plug and perf designs.
Key Benefits:
- Mechanical isolation using expandable liner technology delivered a more reliable and effective method compared to cementing casing
- Expandable liner technology allows for consistent repeatability in terms of mechanical isolation and operational costs
- Expandable liner saves significant cost by negating the need to drill further wells to boost production
- Long Length, Single Trip – with no additional runs or equipment required to mill out shoes
- Enables high-rate stimulation, without the need for extreme pressures
- Market leading post expansion ID
