Preventing Wellbore Loss & Screen-Outs with ZoneVu®

Case Study: Independent Oil & Gas Operator

This small independent is an active operator in the Austin Chalk and the underlying Eagle Ford formation in South Texas. The Austin Chalk is renowned for its prolific hydrocarbon output, but its complex geology and high potential for wellbore stress mean that successful development requires meticulous, integrated pre-planning between geology and engineering teams, with close monitoring of live frac operations.

[Performance Highlights]

0

Casing deformation events across both wells

85%+

Reduction in screen-outs and pressure outs

$140K–$160K

Direct savings from avoided screen-out flushes

$250K–$1M+

Avoided remediation and lost opportunity from prevented casing deformation

On curve

Production at or above type curve across both wells

ZoneVu® Solution: Integrated Data and Teams

ZoneVu is a cloud-based geologic software and operations system for geosteering and completions. It was designed to unite asset teams in the way this operator needed for a high-stakes two-well zipper-frac in the Austin Chalk. Their engineering and geology teams used ZoneVu Frac™ to integrate seismic, image logs, and live operational data. The goal: proactively identify and mitigate risks to prevent wellbore loss from casing deformation and minimize screen-out events.

Understanding the Risks

Casing Deformation

Documented cases in the play point to geologic stresses (such as fault slip or formation compaction) that can cause the steel casing to bend, buckle, or collapse. This can restrict wellbore access, and during hydraulic fracturing, can result in rupture and permanent loss of productive stages. This can potentially cost $250,000 to $1,000,000 or more per remediation and can even result in total wellbore loss if the issue is near heel.

Bridge-Outs & Screen-Outs

These are typical completions issues where physical blockages (bridge-outs) in fractures or in the wellbore can escalate into pressure outs and screen-outs. Each event leads to lost reservoir contact, increased non-productive time, equipment risk – and typically costs ~ $20,000 per remediation flush for each affected stage.

ZoneVu’s Data Integration Acts as an Early Warning System

“ZoneVu helped us be more predictive, do our homework, and avoid expensive problems.”

Director of Completions

ZoneVu Frac™ Data Integration

ZoneVu allowed the operator to compare the near-wellbore lithology, pseudo-logs from the geosteering solution, and MWD curves (GR, ROP, gas shows) – together with 3Dseismic attribute volumes and natural fractures interpreted from the Formation MicroImager (FMI) log. From the roughly 1,400 fractures identified in the FMI log, roughly 100 were believed to have potential to slip or compromise casing. These fractures were visualized in ZoneVu Frac™ as notes (in red) along the two wellbores with their completions designs.

Casing Deformation Risk Identification

The Director of Completions identified that faults oriented N20°–30°, like the dark structure shown in Map View above, are often associated with casing deformation. When these faults are misaligned with regional stress (SHmax), as they were in this case, the completions director believes they are more prone to slip during hydraulic fracturing and cause casing deformation. The team monitored offset well pressure in real time and adjusted the frac operations accordingly. They also tracked communication with the lower lying Eagle Ford to protect frac efficiency.

Preventing Screen-outs: ZoneVu Helps Find Root Cause

During the fracs, the team said they began to experience pressure outs, bridges, and screen-outs on the first 7 of 48 stages on the pad. Using ZoneVu’s integration of geosteering, seismic, image logs, and stage-by-stage frac job data, the team quickly eliminated lithology as the cause. By process of elimination, they identified the root cause was the proppant sieve size being too large. There is a direct correlation between mean proppant diameter and fracture aperture required to accept sand without bridging. After discovering the proppant issue, they reduced screen-outs to just one in the remaining 52 stages.

Screen-Out Troubleshooting

ZoneVu’s integrated data visuals enabled rapid root cause analysis when screen-outs occurred early in the frac program (7 of the first 48 stages). Diagnostics revealed proppant size – not geology – was responsible. After correcting proppant specs, screen-outs dropped to 1 in the next 52 stages, resulting in direct savings of $140,000–$160,000 in avoided flushes alone. Casing Deformation Prevention: By targeting and avoiding high-risk geologic interactions that could cause fault slip along the two wellbores, the operator incurred no casing deformation and preserved full wellbore access. This avoided the severe operational and financial consequences of stage abandonment or major remediation. Conservatively, even a single remediation saved equates to $250,000–$1,000,000+ in avoided costs, not counting lost production revenue or the most catastrophic scenario of a collapsed wellbore (loss).

Results

Production averaged at or above type curve across both wells, confirming success in both risk management and reservoir delivery.
Zero casing deformation events – preserved lateral footage, maximizing reservoir access, and avoided high-dollar remediation and lost production.
Screen-outs and pressure outs reduced by over 85%
Total direct cost savings:
- $140,000 – $160,000 from avoided screen-out flushes
- $250,000 – $1,000,000+ in avoided remediation and lost opportunity from prevented casing deformation

Conclusion

ZoneVu was essential for this operator to execute a proactive and predictive completions execution. Through advanced collaboration with their geoscientists, real-time risk identification, and teamwide visibility, they safeguarded well integrity, reduced operational setbacks, and delivered project-leading production performance with substantial cost avoidance.

Broader Implications

As activity in complex plays like the Austin Chalk accelerates, leveraging platforms such as ZoneVu will be critical for operators to maximize outcomes while minimizing operational and financial risk.

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