Alkali Effect on Alkali-Surfactant-Polymer (ASP) Flooding Enhanced Oil Recovery Performance: Two Large-Scale Field Tests’ Evidence

Table 14

Daqing formation brine composition [86]].

Layer	pH	, mg/L	, mg/L	Cl, mg/L	, mg/L	Ca^2+, mg/L	Mg^2+, mg/L	K^+, mg/L	Na^+, mg/L	TDS, mg/L
S	8.42	139.33	1342.62	2363.87	66.34	25.39	9.44	49.43	2091.06	6037.88
P	8.30	183.30	2285.74	3299.08	280.21	35.97	9.07	217.56	2982.04	9234.84