Question $1$

$(20$ Marks$)$

i$.$ Explain the term Enhanced Oil Recovery $($EOR$)$

ii$.$ Differentiate between Enhanced Oil Recovery $($EOR$)$ and Improved Oil

Recovery $($IOR$)$

iii. Explain the differences between Secondary Recovery methods and

Enhanced Oil Recovery $($EOR$)$

iv$.$ Explain the following terms:

a$.$ Production Enhancement

b$.$ Infill drilling

c$.$ Step$-$out drilling

Question $2$

$(20$ Marks$)$

i$.$ Explain, in detail, the term Displacement efficiency

ii$.$ Use the relative permeability as shown in Table $1$ below to plot the

fractional flow curve for a linear reservoir system with the following

properties:

Dip angle $=0$; Absolute permeability $=50md$;$B_0=1\mathrm{.}20bb\frac{l}{S}TB$;$B_w$

$=1\mathrm{.}05bb\frac{l}{S}TB$;${}_0=45l\frac{b}{f}{t}^3$;${}_w=64\mathrm{.}0l\frac{b}{f}{t}^3$;${}_w=0\mathrm{.}5cp$;

Cross$-$sectional area $A=25,000f{t}^2$

iii. A saturated oil reservoir is under consideration to be waterflooded

immediately after drilling and completion. Core analysis tests indicate that

the initial and residual oil saturations are $70$ and $35\%,$ respectively.

Calculate the displacement efficiency when the oil saturation is reduced

to $65,60,55,50,$ and $35\%.$ Assume that Bo will remain constant

throughout the project life

Table $1$

Question $3$

$(20$ Marks$)$

i$.$ The linear system in Question $2$ii is under consideration for a

waterflooding project with a water injection rate of $1000bb\frac{l}{?}$ day. The oil

viscosity is considered constant at $1\mathrm{.}0cp.$

Calculate the fractional flow curve for the reservoir dip angles of $10,20,$

and $30,$ assuming

a$)$ updip displacement and

b$)$ downdip displacement

ii$.$ The following data are available for a linear$-$reservoir system:

Oil formation volume factor $B_0=1\mathrm{.}25bb\frac{l}{S}TB$

Water formation volume factor $B_w=1\mathrm{.}02bb\frac{l}{S}TB$

Formation thickness $h=20ft$

Cross$-$sectional area $A=26,400ft$

Porosity $=25\%$

Injection rate $i_w=900bb\frac{l}{?}$ day

Distance between producer and injector $L=600ft$

Oil viscosity ${}_0=2\mathrm{.}0cp$

Water viscosity ${}_w=1\mathrm{.}0cp$

Dip angle $\frac{O}{?}=0$

Connate water saturation $S_{wc}=20\%$

Initial water saturation $S_{wi}=20\%$

Residual water saturation Sor $=20\%$

Calculate and plot the water saturation profile after $60,120,$ and $240$

days.

iii. Using the data given in Question $3$ii$,$ calculate:

a$.$ Time to breakthrough

b$.$ Cumulative water injected at breakthrough

iv$.$

c$.$ Total pore volumes of water injected at breakthrough

Table $2($for Question $3$ii$)$