Rb. Gharbi et al., EFFECT OF HETEROGENEITY ON THE PERFORMANCE OF IMMISCIBLE DISPLACEMENTWITH HORIZONTAL WELLS, Journal of petroleum science & engineering, 18(1-2), 1997, pp. 35-47
A three-dimensional, finite difference, chemical flood simulator (UTCH
EM) was used to study the performance of immiscible displacement with
horizontal and vertical wells in several heterogeneous reservoirs. Thr
ee-dimensional heterogeneous permeability fields were generated geosta
tistically with Dykstra-Parsons coefficient and spatial correlation as
characterizing parameters. A total of 21 permeability fields were gen
erated to cover a wide range of Dykstra-Parsons coefficients and spati
al correlations. Initially, simulations of immiscible displacement wit
h two horizontal wells (one injector and one producer) were performed
in all these permeable media. The effect of the amount of cross flow b
etween producing layers on the flood performance was investigated. The
se results were then compared to those obtained with two vertical well
s (one injector and one producer) for all the permeable media. Finally
, investigations were carried out on a heterogeneous reservoir to stud
y in detail the sensitivity of the displacement performance to the hor
izontal well length and to the ratio of horizontal to vertical permeab
ility using various well combinations. These well combinations consist
ed of vertical injector-vertical producer, horizontal injector-horizon
tal producer, vertical injector-horizontal producer, and vertical prod
ucer-horizontal injector. Results show that the degree and the structu
re of the reservoir heterogeneity have a significant effect on the eff
iciency of immiscible displacements with horizontal wells. Long horizo
ntal wells in highly heterogeneous reservoirs do not necessarily guara
ntee improved oil recovery.