Page 507 - Enhanced Oil Recovery in Shale and Tight Reservoirs

Nomenclature 471

S 2 area defined by the maximum average matrix pressure during the huff time, p max ,
times t huff , m/Lt, psi$hour
S 3 area representing the integral of the average matrix pressure over the puff time
(t puff ) in a cycle, m/Lt, psi$hour
S 4 area defined by the maximum average matrix pressure, p max , times t puff , m/Lt,
psi$hour
S normalized saturation, fraction
S huff area defined by the maximum average matrix pressure during the huff time,
m/Lt, psi$hour
3
3
S org residual oil saturation under gas drive, L /L , fraction or %
S puff area defined by the maximum average matrix pressure during the puff time,
m/Lt, psi$hour
3
3
S w2 remaining (residual) oil saturation (S w2 ) at the end of core flood, L /L ,
fraction or %
3
3
S wc connate water saturation, L /L , fraction or %
3
3
S wf water saturation behind imbibition front, L /L , fraction or %
3
3
S wi initial water saturation, L /L , fraction or %
t time, t, s, hours or days
T temperature, T, F, C

T 2 transverse relaxation time in porous medium, t, ms
T 2,bulk transverse relaxation time in bulk liquid t, ms

T a ambient temperature, T, K

T a,c critical ambient temperature, T, K
t D dimensionless time
T E echo spacing of measurement sequence, t, ms
t g ratio of viscous force to gravity force
t huff huff time, t, days
T p parameter in a capillary desaturation curve equation for phase p
t puff puff time, t, days

T r reservoir initial temperature, T, K

T SI spontaneous ignition temperature, T, K
T j trapping number parameter for phase j, dimensionless
u L superficial Darcy velocity, L/t, m/s, ft/d
U Darcy velocity, L/t, m/s
3
3
vorV volume, L ,m ,cm 3
v L interstitial velocity, L/t, m/s, ft/d
v Lc critical interstitial velocity, L/t, m/s, ft/d
3
V o oil volume, L , or oil spontaneous imbibition volume, L 3
V o2 normalized oil volume imbibed into the dry plug 2, L 3
3
V om volume of oil in the microemulsion, L ,cm 3
3
3
V or rock bulk volume whose pores are fully saturated by oil, L ,m ,cm 3
V osi oil spontaneous imbibition volume, L 3
3
3
V p pore volume, L ,m ,cm 3
3
3
V r rock grain volume, L ,m ,cm 3
3
V sm volume of surfactant in the microemulsion, L ,cm 3
V w water spontaneous imbibition volume, L 3