7

Question 1

_____ is quantified by comparing initial and final volumes in place. It takes into account volumetric and displacement efficiencies.

Answer 1

Recovery efficiency

Question 2

The different aspects of recovery efficiency are defined and then combined to form _____

Answer 2

overall recovery efficiency

Question 3

_____ accounts for the efficiency of recovering mobile hydrocarbon.

• defined as the ratio of mobile oil to original oil in place at reservoir conditions

Answer 3

Displacement efficiency

Question 4

_____ can approach 100% if residual oil saturation can be driven to zero.

Answer 4

Displacement efficiency

Question 5

One of the goals of enhanced oil recovery processes such as micellar-polymer flooding or miscible flooding is to _____

Answer 5

reduce residual oil saturation and increase displacement efficiency.

Question 6

volumetric factors are needed to determine overall recovery efficiency – this is based on _____

Answer 6

areal efficiency and sweep efficiency

Question 7

_____ must account for both volumetric and displacement
effects. It is therefore defined as the product of volumetric sweep efficiency and displacement efficiency

Answer 7

Overall recovery efficiency

Question 8

variety of patterns

Answer 8

• line drive (direct & staggered)
• three & two-spot pattern
• four-spot pattern
• five-spot pattern
• irregular five-spot pattern layout
• seven-spot pattern
• nine-spot pattern
• peripheral flood pattern

Question 9

The location of injection wells depends on factors such as:

Answer 9

• Reservoir structure
• Injected fluid type
• Displacement mechanism

Question 10

_____ is an estimate of the area being drained by a production well.

Answer 10

Well spacing

Question 11

A reduction in well spacing requires an _____, which is the number of production wells in a specified area.

Answer 11

increase in the density of production wells

Question 12

Well density can be increased by drilling additional wells in the space between wells in a process called _____. It is an effective means of altering flow patterns and improving recovery efficiency, but can be more expensive than a fluid displacement process.

Answer 12

infill drilling

Question 13

Optimum performance may be achieved with the patterns defined by controlling the rates of injectors and producers. These calculations can be performed analytically if we assume:

Answer 13

• The displacing and displaced fluids are incompressible
• The mobility ratio is one
• The reservoir has uniform properties

Question 14

______ is the mobility of the displacing fluid behind the front divided by the mobility of the displaced fluid ahead of the front.

Answer 14

Mobility ratio

Question 15

Mobility ratios less than or equal to one are considered _____, while mobility ratios greater than one are considered ______.

Answer 15

favorable ; unfavorable

Question 16

_____ often occur when gas is displacing oil or water is displacing high viscosity oil.

Answer 16

Unfavorable mobility ratios

Question 17

An example of a flood with a favorable mobility ratio is the _____

Answer 17

displacement of a low-viscosity oil by water

Question 18

varying model parameters to determine the effect on model result

Answer 18

Sensitivity Testing

Question 19

BOAST

Answer 19

Black Oil Applied Simulation Tool

Question 20

MRST

Answer 20

The MATLAB Reservoir Simulation Toolbox

Question 21

OPM

Answer 21

The Open Porous Media

Question 22

finds the pressure distribution for a given time step first then calculates the saturation distribution for the same time step isothermal.

Answer 22

(BOAST) Black Oil Applied Simulation Tool

Question 23

The toolbox consists of two main parts: a core offering basic functionality and single and two-phase solvers, and a set of add-on modules offering more advanced models, viewers and solvers.

Answer 23

(MRST) The MATLAB Reservoir Simulation Toolbox

Question 24

______ provides a set of open-source tools centered around the simulation of flow and transport of fluids in porous media.

Answer 24

(OPM) The Open Porous Media

Question 25

Using finer grids in running the model

Answer 25

sensitivity testing

Question 26

A combination of experience and common sense.

Answer 26

HEURISTIC GRIDDING RULES

Question 27

When strong directional permeability trends _____ exist, the grid system should be parallel to these trends since most models allows flow only across the cell interfaces.

Answer 27

ANISOTROPY

Question 28

_____ (from well to well) best approximates field conditions (requiring the least amount of relative permeability adjustment to match history).

Answer 28

FLOW VIA DIAGONALS

Question 29

_____ (either areal or cross-sectional) to minimize the number of cells not in the simulated region; these cells have no porosity.

Answer 29

Rotate your grid

Question 30

In orienting the grid system, if faults are _____ to the axes, it is much simpler to define them.

Answer 30

parallel

Question 31

If individual data is important, a ______

Answer 31

minimum of three cells should exist between wells

Question 32

Wells should be located as close as possible to the _____; results will not vary significantly as long as the well is in the central-half of the pore volume of the cell.

Answer 32

center of the cell

Question 33

A common sense rule, but one often overlooked, is to _____ when laying out the original grid.

Answer 33

plan ahead for future wells

Question 34

_____ should not vary in pore volume by more than a factor of two for ease of timestep solution.

Answer 34

surrounding cells

Question 35

_____ models are usually easier to define than areal considerations.

Answer 35

CROSS-SECTIONAL GRIDS

Question 36

heuristic gridding rules for cross-sectional grids

Answer 36

• Geologically varying strata • Existing well completions • Future well completions • GOC and WOC

Question 37

_____ presents a special problem in that the size of the aquifer is usually huge when compared to the reservoir.

Answer 37

Modeling an aquifer

Question 38

_____ may be modeled using boundary modifications

Answer 38

Aquifer

Question 39

Using an exceptionally long cell length would invalidate _____

Answer 39

transmissibility

Question 40

______ incorrect fluid movement due to the gridblock effect.

Answer 40

numerical dispersion

Question 41

we must be concerned with _____ due to the fact that unless a very fine grid is employed, several cells will contain only part of the reservoir.

Answer 41

partial cells

Question 42

must be calculated to fit the grid

Answer 42

cell property determination

Question 43

is accomplished by modifying transmissibilities, pore volumes, and rates

Answer 43

partial field modeling

Question 44

allows the use of a fine grid within a coarse grid, as for example, defining well cells in a field-wide model

Answer 44

Local Grid Refinement (LGR)

Question 45

allows the use of non-orthogonal shapes in describing reservoirs

Answer 45

Corner Point Gridding

Question 46

pakopya a. yes b. no

Answer 46

yes lang ang sagot