The opportunity to refracture low-producing horizontal wells, which have been fractured few months before is getting more and more popular in the last few years. It provides the opportunity of restoring production without drilling new wells, which might be economically feasible especially in the oil and gas low price environment. However, the success rate of refracturing operations is usually low, mainly driven by the inability to properly stimulate the entire horizontal section. Consequently, many operators do not widely deploy this efficient technology. In contrast, completing a newly drilled well with plug and perf technology allows to individually treat from forty to sixty or even more individual compartments in the lateral section while refracturing attempts to retreat the entire lateral in the absence of any isolating device while trying to cover the entire lateral.
There are at least two key factors affecting this operation. First is diversion technology: without efficient chemical diverters, which allow to temporarily block recently treated intervals and divert the stimulation fluid to different open sections of the well is extremely challenging. These diverters should normally be able to hold pressure differentials up to thousand psi or more. Attempting a treatment without this technology, aka a "blind frac" is not an option in many cases. The second factor is monitoring technology: The ability to recognize whether a zone has been successfully stimulated, to decide on the deployment of diverting technology or the further addition of stimulation fluid, to sponsor lateral coverage with minimal risk of premature screen out becomes of utmost importance for the successful outcome of hydraulic refracturing operations. In the absence of either of the aforementioned factors hydraulic refracturing may become inefficient and yield uneconomic success.
This paper presents how the application of novel diverters, combined with proper hydraulic fracturing fluid selection, sound engineering design and more importantly hydraulic fracturing monitoring provide a new opportunity for the deployment of hydraulic refracturing to provide significant production increase and enhance recovery factor.