SPE Reservoir Characterization 3

Question 1

What is the Archie equation primarily used to calculate in petrophysics?

Accepted Answer

Water saturation from resistivity and porosity measurements

Answer

Formation compressibility from sonic logs

Answer

Gas-oil ratio from production logging

Answer

Net pay thickness from gamma ray cutoffs

Question 2

In geostatistical reservoir modeling, what is the key difference between Sequential Gaussian Simulation (SGS) and Kriging?

Accepted Answer

SGS produces multiple equiprobable realizations while Kriging produces a single smooth best-estimate

Answer

Kriging honors well data while SGS does not

Answer

SGS only applies to categorical variables while Kriging applies to continuous variables

Answer

Kriging requires variogram analysis while SGS does not

Question 3

Which core analysis technique directly measures the three-dimensional pore network geometry without destroying the sample?

Accepted Answer

Micro-CT scanning

Answer

Routine core analysis (RCA)

Answer

Dean-Stark extraction

Answer

Soxhlet extraction

Question 4

What is the primary driving force for fluid flow in a petroleum reservoir according to Darcy's Law?

Accepted Answer

Pressure gradient

Answer

Fluid density contrast

Answer

Temperature gradient

Answer

Capillary pressure

Question 5

In a carbonate reservoir, which diagenetic process most commonly creates secondary porosity after deposition?

Accepted Answer

Dolomitization and dissolution (karstification)

Answer

Compaction of aragonite grains

Answer

Clay mineral precipitation from formation water

Answer

Silica cementation of pore throats

Question 6

What does the 'net-to-gross' (NTG) ratio represent in reservoir description?

Accepted Answer

The proportion of the gross reservoir interval that meets minimum petrophysical cutoffs for pay

Answer

The ratio of recoverable reserves to original oil in place

Answer

The ratio of horizontal to vertical permeability

Answer

The fraction of reservoir under structural closure

Question 7

Which seismic attribute is most sensitive to changes in fluid content within reservoir sands?

Accepted Answer

Amplitude versus Offset (AVO) anomaly

Answer

Coherence (similarity)

Answer

Acoustic impedance inversion

Answer

Dip azimuth