SPE Reservoir Engineering & Management 3

Question 1

Which dimensionless number governs the ratio of viscous to gravity forces during reservoir fluid displacement?

Accepted Answer

Gravity number

Answer

The gravity number (ratio of gravity to viscous forces) determines whether gravity override or underride occurs during immiscible displacement.

Question 2

In a naturally fractured reservoir (Type 1 NFR), the matrix blocks primarily act as:

Accepted Answer

Storage volumes that feed fluids into fractures

Answer

In Type 1 NFRs, the matrix provides the dominant storage capacity while the fracture network provides flow capacity (permeability) to the wellbore.

Question 3

The Lorenz coefficient is used in reservoir engineering to quantify:

Accepted Answer

Vertical heterogeneity of permeability

Answer

The Lorenz coefficient (0 = perfectly homogeneous, 1 = perfectly heterogeneous) measures permeability variation across reservoir layers from a flow capacity plot.

Question 4

During secondary recovery by waterflooding, the economic limit is typically reached when:

Accepted Answer

The incremental oil revenue no longer covers lifting costs at prevailing WOR

Answer

The economic limit occurs when the value of incremental oil production no longer justifies operating costs, often at very high water-oil ratios.

Question 5

Which EOR method is most suitable for a high-temperature, high-salinity carbonate reservoir with moderate viscosity oil?

Accepted Answer

Miscible CO2 injection

Answer

Miscible CO2 injection is effective in carbonates with moderate viscosity oil because CO2 achieves miscibility at attainable pressures and is less sensitive to salinity and temperature than chemical EOR.

(SPE) Society of Petroleum Engineers Certification Practice Test

(SPE) Society of Petroleum Engineers Certification Practice Test

SPE Reservoir Engineering & Management 3