CMM Exploration & Production Processes 2

Question 1

Which drilling fluid system is most commonly used in shale formations to prevent wellbore instability?

Accepted Answer

Oil-based mud or synthetic-based mud

Answer

Oil-based or synthetic-based muds inhibit clay swelling and maintain shale stability better than water-based systems.

Question 2

What is the primary purpose of a casing shoe test (LOT/FIT) conducted after drilling out new casing?

Accepted Answer

To determine formation fracture gradient at the casing shoe

Answer

The Leak-Off Test establishes the maximum mud weight window and verifies the formation can support planned drilling pressures.

Question 3

In reservoir engineering, what does the term 'skin factor' indicate when it is a positive number?

Accepted Answer

Damage near the wellbore reducing flow capacity

Answer

A positive skin factor indicates near-wellbore damage (e.g., from mud filtrate invasion or scale) that restricts flow.

Question 4

Which seismic attribute is most useful for directly detecting hydrocarbons by identifying amplitude anomalies?

Accepted Answer

Amplitude versus offset (AVO)

Answer

AVO analysis exploits how seismic amplitude changes with source-receiver offset to identify gas-charged or fluid-saturated sands.

Question 5

What is the main advantage of horizontal drilling compared to vertical drilling in tight or shale reservoirs?

Accepted Answer

Greater reservoir contact length enabling economic production

Answer

Horizontal laterals expose hundreds to thousands of feet of pay zone, dramatically increasing drainage area and production rates.

(CMM) Certified Mineral Manager Practice Test