The Hydrocarbon Highway – Chapter 7

Chapter 7 – Pregnant Ladies and Fish Bones examines the engineering and scientific principles
behind drilling complex well trajectories used to reach and produce hydrocarbons efficiently.
The chapter explains how seismic imaging guides drilling decisions, how well paths are designed
and optimized, and how new technologies such as rotary steerable systems, digitalisation, and
intelligent well completions are reshaping the modern upstream industry.

Overview

• Introduces seismic imaging as the primary tool for identifying subsurface formations.
• Explains the design of complex well paths — including “pregnant lady” and “fishbone” profiles.
• Discusses drilling optimization, risk reduction, and performance planning.
• Outlines formation evaluation techniques including mud logging, LWD, and wireline logging.
• Shows how geosteering and rotary steerable systems improve reservoir contact.
• Describes emerging digitalisation and intelligent completion technologies.

Key Technical Concepts

• Seismic Imaging – Mapping subsurface geometries using acoustic reflection data.
• Well Planning – Creating drilling blueprints balancing geology, mechanics, and cost.
• Formation Evaluation – Using cuttings, logs, and sensors to characterize reservoirs.
• Rotary Steerable Systems – Tools enabling continuous directional control while drilling.
• Geosteering – Real-time trajectory correction to maximize reservoir exposure.
• Expandable Tubulars – Technology to maintain hole diameter and manage trouble zones.
• Digitalisation & Smart Wells – Real-time surveillance and autonomous inflow control.

Case Studies and Practical Insights

• Imaging deep and subsalt reservoirs using multi-azimuth seismic acquisition.
• Reducing non-productive time through drilling well optimization planning (DWOP).
• Controlling vibration and tool wear in abrasive formations via real-time telemetry.
• Increasing production in mature fields via zonal isolation and intelligent completions.
• Adapting well architecture for deepwater environments with high rig day-rates.

Summary

The chapter demonstrates how modern drilling integrates geology, physics, digital data,
and advanced downhole tools to reduce uncertainty and maximize hydrocarbon recovery.
Complex well trajectories and intelligent completions offer operators precision, control,
and efficiency, reshaping exploration and development strategies worldwide.

Download Chapter 7

Download Chapter 7 (PDF)