Table 3. Experimental and Calculated Oil Production with Time-Varying Injection Pressure between 3.44 and 2.41 MPa versus Time.

	oil production (g)
polymer concentration (ppm)	experimental	calculated	numerical software	RMSE	relative error (%)
1000	77.05	75.90	52.54	2.347	1.46
2000	76.80	77.76	61.98	1.381	3.89
3000	60.85	59.85	49.14	2.343	1.63
4000	57.34	55.72	48.36	2.375	2.82
5000	56.62	57.78	45.76	1.552	2.05