Underbalanced Drilling (UBD)

Underbalanced Drilling (UBD)​​

Unlocking Maximum Reservoir Potential​

At Alpine Energy, our Underbalanced Drilling (UBD) services are designed to optimize reservoir performance by drilling with wellbore pressures lower than the formation pressures. This advanced drilling technique promotes safer operations and maximizes the extraction of hydrocarbons.

Alpine Energy Services

Brief Process Overview

Underbalanced Drilling (UBD) is a process that involves carefully managing the pressure in the wellbore to be lower than the pressure in the reservoir. This technique helps reduce damage near the wellbore, increase well productivity, and minimize drilling problems, especially in mature fields and horizontal wells. The process begins with analyzing the reservoir and selecting the appropriate drilling fluid. Surface and downhole UBD equipment is then set up to maintain the desired pressure levels. Real-time monitoring is crucial throughout the drilling process to ensure safe and efficient operations. After drilling is complete, the well is prepared for production, with ongoing monitoring to optimize production rates.

Our Underbalanced Drilling (UBD) services manage the flow of reservoir fluids into the wellbore during drilling, reducing near-wellbore damage, enhancing well productivity, and minimizing drilling issues. This technique is particularly beneficial in mature fields and horizontal wells. We offer an extensive fleet of surface and downhole UBD equipment and well engineering expertise. Our real-time reservoir characterization during drilling provides valuable insights into wellbore permeability and pressures, facilitating successful drilling to total depth.

Benefits of UBD


Pressure Controller

The Pressure Controller is built on the latest technology in advanced adaptive control, typically used in autonomous aircraft for extreme performance and robustness. The Pressure Controller allows the driller to choose one of four control modes.


  • Choke pressure (single/dual)
  • Downhole pressure (requires Hydraulic Model)
  • Standpipe pressure
  • Choke flow

The Pressure Controller is resilient against any sensor failures and downhole well incidents.

The choice of control mode does not affect the overall performance

Hydraulic Model​

Our hydraulic model is a high-performance, real-time downhole pressure estimator that is tested and verified with field data. It captures the downhole dynamics and is both easy to configure and calibrate. The Hydraulic Model can be used standalone or with the choke Pressure Controller.


  • Estimates downhole pressure at any location (virtual sensors)
  • Automatic Calibration
  • Continuous estimation between PWD updates (e.g. connections) or manual calibration (calculated)
  • Handles circulation, drilling, connections, multi-fluid operations, surge-swab and more.

Influx-Loss Detection​

The Influx-Loss Detection module is a kick detection algorithm that can detect symptoms of downhole incidents before they evolve into a well control event. It has been tested against the Hydraulic Simulator in real life and accounts for transient drill operations (connections, pressure set-point changes, surge, and swab effects) to avoid false alarms.


  • Enable earlier detection of influx/loss
  • Avoid false alarms
  • Single-most cost-effective measure to reduce Non-Productive Time (NPT) caused by kick/loss incidents.