Page 111 - Enhanced Oil Recovery in Shale and Tight Reservoirs

98 Enhanced Oil Recovery in Shale and Tight Reservoirs

With richer compositions of a reservoir fluid, the performance difference
in gas and solvent huff-n-puff is magnified, with significantly higher
recovery factors from methane and ethane injection. Solvents recover
intermediate fluids really well and can be competitive with gas huff-
n-puff for lean gas condensate fluids. Isopropanol is a better solvent than
methanol for recovering heavier components; however, higher costs may
not favor its application.

4.6 Reservoir-scale modeling of gas and solvent
performance
The preceding section is based on core-scale modeling. This section
focuses on reservoir-scale modeling. The grid blocks of the reservoir-scale
model are shown in Fig. 4.20. The matrix permeability is 304 nD,
and the porosity is 5.6%. The fracture spacing is 2.27 ft in the non-SRV
(stimulated reservoir volume) zone and 0.77 ft in the SRV zone. For
more details, refer to Sheng et al. (2016).

Figure 4.20 Reservoir-scale grid model based on Sheng et al. (2016).