Table 1.

Physicochemical properties of the samples from Jiangsu oil reservoirs.

	Block W2		Block W9		Block W11
	2-53	2-71	9-18	9-14	11-7	11-6
Depth (m)	1538	1499	1809	1837	2143	2057
Temperature (°C)	67.6	66.2	79.6	75.8	72.3	71.5
pH	8.12	8.23	8.03	7.82	7.90	7.84
Water flooding (year)	18	18	0	15	10	10
Corrosion rate (mm year-1)	0.066	0.064	0.031	0.039	0.101	0.236
TDS (g l-1)	23.01	24.49	24.41	25.04	25.4	24.45
Water content (%)	79.3	89.4	96.1	79.4	75.4	94.5
Na+ (g l-1)	4.14	4.06	5.12	5.68	5.54	3.36
Mg2+ (mg l-1)	11.54	8.86	18.23	23.31	28.72	16.53
Ca2+ (mg l-1)	28.17	33.19	36.12	78.65	101.92	63.92
NH4+ (mg l-1)	64.8	24.82	56.84	69.83	58.96	60.18
K+ (mg l-1)	200.07	24.51	175.13	227.82	215.89	215.29
${\mathrm{S}\mathrm{O}}_{\mathrm{4}}^{\mathrm{2}\mathrm{-}}$ (mg l-1)	244.0	83.4	182.2	297.0	533.7	193.4
${\mathrm{N}\mathrm{O}}_{\mathrm{3}}^{\mathrm{-}}$ (mg l-1)	1.50	9.11	2.22	1.97	5.97	0.81
${\mathrm{C}\mathrm{O}}_{\mathrm{3}}^{\mathrm{2}\mathrm{-}}$ (g l-1)	3.12	2.95	1.90	1.49	1.10	1.16
S2- (mg l-1)	9.39	8.42	9.69	9.87	8.37	6.86
${\mathrm{S}\mathrm{O}}_{\mathrm{3}}^{\mathrm{2}\mathrm{-}}$ (mg l-1)	nd	nd	nd	10.63	nd	nd
Cl- (g l-1)	4.03	4.37	6.82	8.23	8.22	4.75
${{\mathrm{S}}_{\mathrm{2}}\mathrm{O}}_{\mathrm{3}}^{\mathrm{2}\mathrm{-}}$ (mg l-1)	92.14	89.65	149.6	126.8	38.54	4.11
Formate (mg l-1)	2.36	2.16	12.88	22.08	18.71	0.76
Acetate (mg l-1)	48.75	24.48	84.73	108.6	159.26	46.96
Propionate (mg l-1)	13.36	5.79	7.92	8.49	12.51	3.98
Butyrate (mg l-1)	0.73	0.92	1.12	1.06	1.19	0.86

nd, not detected; TDS, total dissolved salinity.