CPG Study Guide 2026
Everything you need to pass the CPG exam in one place: the exam format, every topic to study, real practice questions with explanations, flashcards, and full-length practice tests. Free, no sign-up needed.
📋 CPG Exam Format at a Glance
📚 CPG Topics to Study (72)
✍️ Sample CPG Questions & Answers
1. Which log measurement is the primary direct indicator of formation fluid pressure in permeable zones while drilling?
The Repeat Formation Tester (RFT) or Modular Dynamic Tester (MDT) directly samples formation fluid and measures pore pressure at discrete depth intervals.
2. What is the role of 'risked exploration potential' at the basin scale when a company is evaluating new license areas?
Risked exploration potential aggregates probability-weighted undiscovered resource estimates across all plays, helping companies rank and compare basin-entry opportunities.
3. Which practice best ensures reproducibility of a geological interpretation for peer review?
Transparent documentation of all methods, data, and decisions allows independent replication and critical evaluation of the interpretation.
4. A petroleum geologist discovers a significant reserve estimate discrepancy between their internal model and a third-party audit. What is the most professionally appropriate first step?
Professional standards require transparent disclosure of material discrepancies to management with full documentation before any corrective action.
5. Which exploration method measures variations in the Earth's gravitational field to detect subsurface density contrasts?
Gravity surveys detect lateral changes in rock density; salt bodies (low density) produce negative Bouguer anomalies, while dense basement rocks produce positive anomalies.
6. The vitrinite reflectance value (Ro) of approximately 0.5–0.6% corresponds to which stage of organic matter maturation?
Ro values of 0.5–0.6% mark the onset of the early oil window, where sufficient thermal energy has been reached to begin cracking kerogen into liquid hydrocarbons.