TAYLOR O’BRIEN and RICKY MOLLA, AutoSep Technologies
Priorities are evolving for operators in the Appalachian basin, and pad design is no exception to this. Pad sizes are growing smaller, as well counts are growing larger, and pad revisits are becoming more prevalent, with Turn in Line (TIL) dates becoming more challenging for operators to meet.
Historically, traditional flowback spreads would sprawl across pad locations, requiring intensive manpower, high iron counts and large quantities of ancillary equipment, including sand separators, line heaters and high-stage separators. While innovation through technology, safety and automation became a priority on drilling rigs, frac spreads, hydraulic completion units (HCUs) and production/midstream facilities, the flowback market seemed to fall behind. Whereas high-pressure companies prioritized red zone restriction, the flowback industry continued to normalize employee exposure to high-pressure iron or separators for the entire shift.
Fig. 1. AutoSep Control Units combine the four key components into a single skid.
To bring flowback into the modern era, AutoSep Technologies (a JV between CNX and Deep Well Services) introduced its ACU (AutoSep Control Unit) in 2019. From 2020–2023, the system underwent continuous refinement through extensive field trials. Today, these ACUs have been deployed on more than 60 wells across the Marcellus and Utica shale formations, successfully managing flowrates of up to 50 MMcfd and 250 bbl of water per hour. The ACU is changing the game in flowback, bringing a new level of automation and sophisticated safety features to a previously under-innovated market.
ACU TECHNOLOGY DEVELOPMENT
The ACU system combines the four key components of a flowback spread onto a single skid: the sand separator, debris catcher, choke manifold, and high-stage separator. Each skid contains dual 5,000-psi vessels with integrated debris catchers and choke manifolds. The units stand 20 ft tall, and each individual vessel features a 28-in OD and 21.5-in ID, Fig. 1. The vessels contain a proprietary Guided Wave Radar (GWR) that allows the separation of water and sand from the flow stream at the wellbore’s highest pressure. With advanced technology, the GWR maintains a liquid level within the vessel that also allows for automated choke actuation, based on real-time well conditions.
The logic within the Programmable Logic Computer (PLC), as well as quadruple Proportional, Integral and Derivative (PID) Loop settings, allows the system to adjust and react autonomously, without manual manipulation. Redundancies within the logic and hard iron provide a safeguard for the system to swap flowing sides of the manifold, when signs of equipment wear-and-tear are observed. The unit inlet is designed with a custom stinger that allows water and sand to break out of the gas stream, providing sophisticated separation at wellbore pressure. Added to this, the ACU can be monitored remotely from a control room outside of the red zone, Fig. 2.
Fig. 2. Remote operation capabilities eliminate crews' exposure to high-risk red zone areas.
Operators can manually intervene and adjust unit settings as required, if well-flowing conditions dictate intervention. Operators are only required to enter the red zone area for routine maintenance and daily equipment inspections. AutoSep’s easy-to-use, in-house software enables seamless integration with operators' SCADA systems, reducing redundancy in flowback note-taking and automatically populating reports and note-taking emails.
CLEANER SEPARATION
The ACU separates gas at high pressure, reducing erosion on downstream pressure-control equipment. By removing gas earlier in the process, the ACU helps limit wear on critical components. In addition to gas separation, the system also removes sand, debris, solids and water, creating a less-erosive environment for production equipment.
A cleaner gas stream has several advantages. Higher flowrates can be maintained with less concern for erosion, while tubulars and other infrastructure experience less damage over time. The commonly referenced API RP 14E equation, which uses a C-factor constant to estimate allowable fluid velocity, illustrates how difficult erosion prediction can be when solids are present. By removing solids and water, the ACU helps simplify this challenge and reduce maintenance requirements for chokes and other sensitive inline equipment.
The gas exiting the ACU is clean enough to be routed directly into the operator’s permanent production facilities. This seamless transition enables gas metering from day one, reduces downtime, and shortens the path from flowback to full production. The result is a smarter, more efficient, and more reliable way to move gas forward.
ADVANTAGES OF IMPLEMENTING AUTOMATED SOLUTIONS
Fig. 3. AutoSep’s software logs every data point, holding operations to higher accountability with full transparency.
Automation provided through ACU technology offers a transformative advantage in operational environments by delivering consistent, high-fidelity data through digital measurement devices. This continuous stream of real-time input eliminates the risk of human error and prevents data corruption that can occur with manual notetaking or manipulation. With every data point automatically logged by AutoSep’s software, the operation is held to a higher standard of accountability; every action, whether beneficial or detrimental, is transparently recorded, Fig. 3.
This level of precision empowers clients with a clear, accurate understanding of their wells’ performances, enabling informed decision-making. Furthermore, the programmable logic embedded in the systems—driven by historical data—ensures repeatable outcomes regardless of the personnel operating the equipment. This guarantees uniform performance across all deployments of ACUs. By continuously monitoring multiple data sets, the logic-based systems can detect anomalies early, identifying subtle variances that may signal potential issues before they escalate. This proactive approach enhances reliability, safety and operational efficiency across the board.
REDUCING ENVIRONMENTAL IMPACT AND SIF POTENTIAL
AutoSep’s ACU delivers a step-change in flowback emissions control by combining automation with precision separation technology. Its closed-loop, continuous discharge system eliminates the need for sand trap blowdowns, preventing methane releases that typically escape during manual operations.
Fig. 4. AutoSep’s ACUs on site, delivering safer, closed-loop flowback operations that cut emissions, capture more gas, and protect crews in the field.
By carefully managing fluid levels, the ACU eliminates gas blowby, reduces emissions and captures more gas for sales. Real-time monitoring and remote shutdown capability add an extra layer of safety and control, while advanced separation ensures discharge streams are almost entirely liquid. Any vapors that escape are captured and either flared or recovered—transforming what was once wasted gas into additional sales volume, Fig. 4.
This combination of automated control, closed-loop operation and vapor recovery not only protects the environment but also boosts operational efficiency and profitability, helping operators meet growing sustainability and ESG goals.
Beyond emissions, the ACU also plays a critical role in safety. A core objective of the ACU technology is to reduce the potential for Serious Injury and Fatality (SIF). By reducing exposure to high-pressure environments, such as red zones, the system helps protect personnel from hazardous conditions, thereby enhancing overall site safety.
These safety benefits aren’t just theoretical; they’ve been proven in the field. The following case study highlights how the ACU performed under real-world conditions, as well as the measurable impact that it delivered for operators.
RED ZONE EXPOSURE CASE STUDY
Background. In early 2025, AutoSep conducted a comprehensive case study to evaluate and quantify employee exposure to high-risk red zone areas during production flowback operations. The objective was to assess the effectiveness of automation in reducing the potential for Serious Injury and Fatality (SIF) and to provide data-driven insights into personnel safety.
Fig. 5. Combined with AutoSep’s ACU technology and third-party monitoring, established a reliable and repeatable framework for quantifying the reduction in red zone exposure.
Challenge. AutoSep was tasked by a leading upstream operator in the Marcellus shale to address safety concerns associated with high-pressure flowback operations. The operator sought to better understand and quantify red zone exposure per employee, with a focus on mitigating SIF risks through the use of automation and monitoring technologies.
Solution. AutoSep deployed its ACUs—compact, high-precision systems designed for continuous sand separation—on an eight-well pad in Southwest Pennsylvania. To support the study, two third-party camera systems were installed to monitor red zone activity. The ACUs operated autonomously, minimizing manual intervention and allowing for precise tracking of personnel movement within high-risk zones.
Deployment and implementation. Four dual-vessel ACU skids were rigged up to service the eight wells. In parallel, third-party camera systems were positioned to continuously monitor the designated red zone. Once the wells were brought online, a third-party engineering firm conducted a nine-day observation period, documenting employee entry and exit times, as well as total duration spent in the red zone.
Results. During March 18–26, 2025, the study captured data across 216 flowing hours and 792 total man-hours, Fig. 5. Analysis revealed that, on average, an AutoSep employee was present in the red zone for 19% of the time during daily operations, equivalent to 4.5 hrs per day. When examined per individual, the average red zone exposure was 5% of a 12-hour shift, or 36 min. per day. These findings demonstrate a significant reduction in exposure, when compared to traditional flowback methods, highlighting the value of automation in enhancing safety and accountability.
CONCLUSION
AutoSep’s ACU technology, combined with third-party monitoring, has established a reliable and repeatable framework for quantifying red zone exposure. The findings highlight how automation reduces SIF potential, enhances operational transparency and enables early detection of safety risks, demonstrating the critical role of technology in reshaping flowback practices. This case study underscores AutoSep’s commitment to advancing safer, smarter solutions through innovation and data-driven performance.
By integrating high-pressure separation, intelligent control systems and real-time data monitoring, AutoSep Technologies is redefining the standards of flowback operations. The ACU platform consistently delivers measurable improvements in efficiency, environmental stewardship and personnel safety. With proven reductions in red zone exposure and methane emissions across multiple deployments, AutoSep has positioned itself as a leader in modern flowback solutions. As the industry continues to evolve, AutoSep remains dedicated to driving progress, ensuring that cleaner separation paves the way to a safer, more efficient and more sustainable future for energy production.
TAYLOR O’BRIEN is general manager of AutoSep Technologies (a JV between CNX and Deep Well Services), and he has 15 years of experience in upstream and downstream oil and gas, with a focus on drilling, completions and automation. He holds degrees in geology, petroleum engineering and business from Allegheny College, the University of Pittsburgh and Washington State University. At AutoSep, he fosters talent and builds a culture rooted in technology, innovation and operational excellence.
RICKY MOLLA is operations manager at AutoSep Technologies, and he has 14 years of production and completion experience. His leadership at Colter and CNX established his commitment to safe, efficient and innovative operations. At AutoSep, he drives results through trust, reliability and automation.
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