For ARC Resources, one of Canada’s largest natural gas producers, deformation events in lateral and build sections of its wells were creating operational uncertainty. Deformation affects the overall efficiency of plug-and-perf (PnP) operations, specifically the ability to pump down full-size guns and plugs, which, at best, can create difficulty in milling operations and, at worst, can result in skipped stages or lost lateral.
The operator had the data to know deformation was happening. What it lacked was the ability to track it in real time, stage by stage, without sacrificing time on the critical path of the stimulation. Every additional wireline run for a stand-alone log meant added cost, a tied-up wireline unit, and potential delays to stimulation activities.
What followed was a collaborative research and development effort between ARC and acoustic imaging technology company DarkVision that resulted in a novel logging-while-perforating capability.
The approach has since been validated across more than 20 runs with the DarkVision acoustic imaging tool within the gun string, with no impact on perforation operations or tool integrity. Decision-ready data was delivered within hours, enabling decisions to be made before completing the next stage
From CCL Signals to Acoustic Clarity
ARC’s casing deformation diagnostic journey began with interpretation of low-resolution anomalies in casing collar locator (CCL) data. The CCL uses electromagnetic principles to detect changes in pipe thickness and thus detect casing collars. The challenge with CCL logging was that the technology can only flag areas of thickness anomalies but is unable to quantify the severity of deformation at those locations.
Therefore, the next step was stand-alone caliper logging to confirm and quantify the anomalies detected by the CCL. Caliper data offered quantifiable internal diameter measurements and could track the rate of change over time, but it came at a price: additional equipment, an extra wireline run, and time away from the completion program.
Acoustic imaging represented the logical next step. Unlike caliper tools, the high-resolution solid-state acoustic array used in this case study does not require strict centralization, and it provides both dimensional measurement and textural detail of the casing’s inner diameter, capturing ovality, wall loss, and surface anomalies in a single pass. The question was whether it could be deployed inside the gun string and eliminate an additional wireline run.
Engineering a Tool To Survive the Gun String
The gun string is a brutal environment. Downhole shocks generated during perforating and plug setting can be severe, and any tool operating in that string needs to handle not just pressure and temperature but extreme mechanical loading events. Before DarkVision could deploy its acoustic imaging tool in the PnP string, the team needed to understand exactly what they were designing for.
A feasibility study was launched using a downhole data accelerometer deployed on a representative ARC gun run. The recorded data revealed downhole shocks and acceleration in the hundreds of g-force range. Those measurements became the design specification.
The technology developer’s engineering team responded with a series of targeted upgrades. On the mechanical side, hardened alloys were incorporated to improve structural strength, and the thread and shoulder design on connections and knuckles was optimized for shock resilience (Fig. 1). Knuckles and centralizers were redesigned to manage the lateral loads encountered during pumpdown and gun detonation. On the electrical side, an insulated feed-through line was developed to allow gun detonation without interfering with the logging tool’s electronics.
The upgraded tool underwent hundreds of axial and radial force tests, validating not just the imaging probe but the full assembly of electronics and auxiliary components. Only after that testing program was complete did the team move to field trial.
Field Trial: Watching Deformation Unfold in Real Time
The field trial was conducted on two active ARC fracturing programs. The combined DarkVision/perf string was pumped down, the plug was set, the guns were fired, and the acoustic imaging tool recorded the casing interior on the way back to surface. Data turnaround—from tools on surface to a processed deformation log—was targeted at 5 hours.
The run-over-run comparison capability proved to be the most operationally significant output. By establishing a baseline scan before fracturing and then repeating the acoustic image after selected stages, the team could directly observe where and when deformation was occurring and how it progressed with each successive stage (Fig. 2). The acoustic data, with its submillimetric resolution, made deformation events unmistakable where earlier diagnostic methods had left ambiguity.
The implications were immediate. Stage-by-stage deformation tracking gave ARC’s completions team the information they needed to derisk ongoing operations: understanding whether a deformation event was growing, stabilizing, or likely to affect pumpdown operations in upcoming stages. It also provided a more accurate picture for mill-out planning.
An additional benefit emerged around sand delivery logistics. Deformation events disrupt the consistency of stage-to-stage treatment volumes and pressures. With better prediction of which stages might be affected, ARC was able to improve the reliability of its sand forecasts, reducing trucking standby time and cutting associated costs.
Performance and Operational Results
Following the initial toolstring optimization, the technology developer successfully executed more than 20 logging-while-perforating runs. The upgraded tool design sustained zero failures attributable to downhole shock loading. Analysis was delivered to the operations team within the target window throughout the program, enabling real-time decision support during active fracturing.
Beyond the deformation monitoring use case, the program also validated the concept of collecting prefrac perforation data using the DarkVision tool in the same run. Acoustic imaging of the perforations offers additional diagnostic value for completions optimization that the team is now positioned to use on future wells.
The project also demonstrated the feasibility of wellhead scanning for erosion during PnP runs, adding yet another monitoring capability to a single toolstring deployment.
Lessons for Industry
ARC and DarkVision continue to build on the trial’s success with several workstreams. The imaging tool will be repositioned below the gun string to enable prefrac perforation evaluation alongside deformation scanning in a single run. The teams are also working to optimize setting tools for different plug types, studying the incremental forces imposed on both plugs and the imaging tool and sharing findings with setting tool and plug manufacturers to inform slimhole versus conventional plug selection.
The broader significance of the project may lie less in any single capability than in the workflow model it demonstrates. By embedding diagnostic instrumentation into an existing operational toolstring, operators can collect high-value subsurface data at near-zero incremental cost to the completion schedule.
For ARC Resources, the investment in that engineering effort has yielded a system that monitors casing health continuously through the stimulation program, delivers actionable data within hours, and does so without adding a single wireline run to the completion schedule. In a business where nonproductive time is measured in hundreds of dollars per minute, that outcome speaks for itself.
Key Takeaways
- Downhole shocks exceeding several hundred g (times the force of gravity) were measured and used to design mechanical upgrades that improved tool strength.
- Run-over-run deformation analysis was delivered, enabling real-time operational decisions during active fracture stimulation.
- More than 20 logging-while-perforating runs were completed with zero tool damage following toolstring optimization.
- Improved deformation tracking reduced trucking standby costs by enabling more consistent sand delivery forecasts.
- Future work will add prefrac perforation evaluation and wellhead erosion scanning to the same single-run workflow.
Editor’s Note: ARC Resources was acquired by Shell in September 2026 following the completion of this case study. References to ARC Resources throughout the article reflect the company’s status at the time the work was conducted and documented.
Adrian Campbell, SPE, is staff completions engineer at ARC Resources. He holds a BS degree in petroleum engineering with honors from the University of Alberta and brings more than 20 years of experience in drilling and completions engineering, including roles in field superintendence and management. Campbell is active in the industry as a Carpinteria Advanced Purification Project well construction representative and is chair of the Drilling and Completions Committee for Energy Safety Canada.
Johnny Wentzel is a technical sales engineer at DarkVision based in Calgary. He has 15 years of experience in the Canadian oil and gas industry with a background in passive acoustic monitoring and downhole acoustic imaging for completions optimization. Wentzel’s recent work has focused on introducing operators to high-resolution casing-integrity logging across upstream and midstream applications, including deployment of a first-of-its-kind acoustic imaging tool within a perforating string for casing deformation monitoring. He holds a BS degree in geological engineering from Queen’s University.