SPE Drilling Engineering Principles 2

Question 1

What is the primary purpose of a drill stem test (DST) in petroleum engineering?

Accepted Answer

To evaluate reservoir pressure, permeability, and fluid type before completing the well

Answer

A DST evaluates formation fluid characteristics, reservoir pressure, and permeability to determine whether a well is commercially viable.

Question 2

In directional drilling, what does the term 'dogleg severity' (DLS) measure?

Accepted Answer

The rate of change in wellbore inclination and azimuth per 100 feet

Answer

Dogleg severity measures the rate of change in wellbore direction (both inclination and azimuth) per 100 ft, expressed in degrees per 100 ft.

Question 3

Which drilling fluid property describes its ability to suspend cuttings when circulation is stopped?

Accepted Answer

Gel strength

Answer

Gel strength measures the thixotropic properties of drilling fluid that allow it to suspend cuttings and weighting materials when pumps are off.

Question 4

What is the function of a float valve (check valve) installed in the drill string?

Accepted Answer

To prevent backflow of formation fluids up through the drill pipe

Answer

A float valve prevents wellbore fluids and gases from flowing back up into the drill string, helping to control kicks and maintain well control.

Question 5

The equivalent circulating density (ECD) is higher than the static mud weight because:

Accepted Answer

Annular friction pressure losses add to the hydrostatic pressure

Answer

ECD equals static mud weight plus the additional pressure due to annular friction losses from fluid circulation, expressed as an equivalent density.

(SPE) Society of Petroleum Engineers Certification Practice Test