Table 4. Summary of Economic Cost for PEG and PPG Hydrogels on the Lab Scale.

hydrogel	PEG		PPG
hydrogel conc. g/L	1	1.5	1	1.5
hydrogel conc., lb	0.0022	0.0033	0.0022	0.0033
recovered oil volume after waterflooding (recovered from residual oil), cc	10	12	18	22
recovered oil volume after waterflooding (recovered from residual oil), bbl	6.29 × 10–5	7.55 × 10–5	1.13 × 10–4	1.38 × 10–4
slug efficiencya	35.0	43.7	19.4	23.8
cost of chemical, $	3.81 × 10–4	5.72 × 10–4	5.08 × 10–4	7.62 × 10–4
cost of consumed hydrogel/oil barrelb, $	6.06	7.58	4.49	5.51

^aSlug efficiency was calculated by dividing the mass of injected chemical (pounds, lb) by the volume of recovered oil (barrels, bbl).

^bCost of hydrogel/oil barrel was calculated by dividing the cost of chemical, $/recovered oil volume after waterflooding (recovered from residual oil), bbl.