Oil and Gas Wells, Revived

Refracturing, or refrac, of oil and gas wells involves restimulating existing wells to enhance hydrocarbon recovery, a practice tried in the 1950s and refined in the last 20 years. Initially, refracs were rudimentary, targeting understimulated zones with basic hydraulic fracturing techniques. Advances in reservoir characterization and completion technologies have since elevated refrac to a strategic tool for maximizing production in mature fields.

Original Production Decline

Production decline in wells stems from reduced reservoir pressure, proppant degradation, formation damage, or incomplete stimulation of the target zone. Fluid-rock interactions, stress shadowing, and reservoir heterogeneity further exacerbate decline, leaving significant hydrocarbons stranded. Currently around half of all US crude production comes from frac’d wells.

Wellbore and Formation Considerations

Wellbore diameter critically influences refrac feasibility. Smaller diameters (e.g., 4.5–5.5 inches) limit tool deployment and fluid injection rates, necessitating specialized equipment. Rock type also governs refrac design: brittle shale formations respond favorably to restimulation, while ductile or high-clay-content formations may require tailored proppant schedules or chemical additives to maintain fracture conductivity. Geomechanical analysis of stress changes post-initial frac is essential to optimize refrac placement.

Cost Analysis and Crude Oil Price Impact

Refracturing typically costs 25–50% of a new well, averaging $1–3 million compared to $6–10 million for new drills, depending on basin and well complexity. High crude oil prices incentivize refracs, as operators seek to capitalize on existing infrastructure. Conversely, low prices may deter refrac investments, favoring new wells in untapped reservoirs with higher initial rates.

Parent/Child and Field Considerations

Parent-child well interactions, where new child wells degrade parent well performance due to pressure depletion or frac hits, are critical in refrac planning. Whole-field optimization now integrates reservoir simulation to prioritize refrac candidates, balancing inter-well interference and maximizing net present value. Advanced data analytics, including production logging and tracer studies, identify refrac targets by quantifying remaining reserves and stimulation potential.

Data-Driven Refrac Decisions

Improved data and technology, such as 4D seismic, machine learning-based decline curve analysis, and fiber-optic monitoring, enable precise identification of refrac candidates. These tools quantify reservoir heterogeneity, stress evolution, and bypassed pay zones, enhancing decision-making. By integrating petrophysical and production data, operators can prioritize wells with high refrac potential, optimizing capital allocation and recovery efficiency.

Innovations in Refracturing Technology

Refracturing continues to evolve, driven by technological innovation and economic imperatives, offering a cost-effective strategy to unlock stranded hydrocarbons in mature fields. Modern refrac techniques leverage advanced diagnostics, such as microseismic monitoring and distributed acoustic sensing (DAS), to map unstimulated zones.

The Next Big Thing?

Our innovative biomineralization technology has quickly become the most effective solution for restoring barrier integrity and shows promise as an alternative to recompletions and diverters for refrac applications due to its ability to access and seal fractures with new material. Tests conducted on a fractured and subsequently sealed shale core showed that new fractures formed on a different plane at over three times the original pressure, potentially providing access to untouched hydrocarbons.

Learn More

Interested in learning more about refrac operations, data analysis, and technical options?

Join us at the upcoming SPE Workshop: Refracturing—A Proven Strategy To Maximize Economic Recovery | May 19-20 in San Antonio, Texas