Underbalanced Drilling
Principles, Planning & Operations

Duration: 5 Days
Target Audience: Drilling Engineers, Well Planners, Completions Engineers, Wellsite Supervisors, Operations Engineers, HSE Personnel
Delivery Mode: Classroom / Virtual with Calculations, Design Workshops, and Case Studies
Level: Intermediate to Advanced

Course Overview

This course provides comprehensive knowledge of underbalanced drilling (UBD) technologies, including planning, equipment selection, operational procedures, risks, and benefits. Participants will learn about UBD fluids, multiphase flow considerations, rotating control devices, surface equipment, well control in UBD, and case histories to improve drilling performance and reservoir productivity.

Day-by-Day Outline

Day 1 – Fundamentals of Underbalanced Drilling

- Definition and applications of UBD
- Advantages and limitations of UBD vs. conventional drilling
- Types of UBD operations: air drilling, mist, foam, nitrified fluids, light mud
- Reservoir benefits: minimized formation damage, increased ROP
- Exercise: Evaluate when to apply UBD in different reservoir scenarios

Day 2 – UBD Fluids & Multiphase Flow

- Types of UBD fluids and their selection criteria
- Properties of compressible drilling fluids
- Multiphase flow behavior in the annulus
- Pressure and temperature considerations in UBD
- Workshop: Calculate required gas injection rates for different UBD systems

Day 3 – UBD Equipment & Surface Systems

- Rotating control devices (RCDs) and their role in UBD
- Choke manifolds and surface pressure control
- Separation equipment: separators, degassers
- Downhole tools for UBD applications
- Exercise: Design surface equipment layout for an underbalanced operation

Day 4 – Planning & Well Control in UBD

- Planning well profiles and casing programs for UBD
- Challenges in directional and horizontal UBD wells
- Managing influxes and maintaining control with multiphase flow
- Safety and HSE considerations in UBD
- Workshop: Prepare a UBD drilling program with risk assessment

Day 5 – UBD Case Studies & Performance Analysis

- Review of successful UBD projects in various basins
- Common operational problems and troubleshooting techniques
- Economic evaluation of UBD projects
- Integrating UBD into field development plans
- Capstone Project: Analyze a UBD case and develop an optimized UBD plan with recommendations

Expected Learning Outcomes

Understand the principles and benefits of underbalanced drilling
Design and select appropriate UBD fluids and equipment
Plan well programs considering UBD-specific challenges
Manage well control and multiphase flow risks in UBD
Evaluate and troubleshoot UBD operations for performance improvement

Customizable Add-ons
Tailored content for local geology (e.g. Nile Delta, Western Desert)
Lab visit or simulation hands-on demo
Integration with economics or production courses

Special Customization for Regional NOCs

- Includes legal and fiscal case examples from MENA & Africa
- Arabic-English bilingual delivery available
- Tailored licensing round simulation exercises
- Optional site visits to local oilfields or regulatory agencies

Trainer Profile

- Senior reservoir and exploration engineers from IOCs and NOCs
- Former advisors to government ministries
- Experts in petroleum contracts and economic modeling

Certification

Participants will receive a Certificate of Completion and a performance report including assessment outcomes and instructor feedback.