Petrophysics

Reservoir Engineering
By OgbonLab

Read the rock from logs: the full formation-evaluation workflow, hands on.

Read the rock from well logs: from gamma ray and porosity to saturation, permeability, and net pay, from first principles to confident formation evaluation.

4 parts 19 sections Free, browser-native
Start reading → First up: What Petrophysics Asks

Table of contents

Every section is a working session: text, math, code, interactive widgets. Click any title to jump in.

Part 1: Chapter 1: Rocks, Pores, and Fluids

  1. What Petrophysics Asks
  2. Porosity: The Space in the Rock
  3. Saturation: Filling the Pores
  4. Permeability: Can It Flow
  5. The Fluids and Their Contacts
  6. Reading a Well: The Log Display

Part 2: Chapter 2: The Logging Environment and Invasion

  1. The Borehole and Drilling Mud
  2. Formation Water and Mud Filtrate
  3. Invasion: Flushed and Virgin Zones
  4. Depth of Investigation
  5. Borehole and Environmental Effects
  6. How Logs Measure

Part 3: Chapter 3: Gamma Ray and Spontaneous Potential

  1. The Gamma Ray Log
  2. Shale Volume from the Gamma Ray
  3. Spectral Gamma Ray
  4. The Spontaneous Potential Log
  5. Reading Rw from the SP
  6. Reading Gamma Ray and SP Together

Part 4: Chapter 4: Density and Neutron Porosity

  1. The Density Log

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