Understanding of Long-Term CO₂-Brine-Rock Geochemical Reactions Using Numerical Modeling and Natural Analogue Study

Table 1

Volume fractions of minerals in sandstone samples taken from the Longtan Formation (converted from XRD analysis data).

Number	Well	Depth (m)	Quartz (%)	Illite (%)	Kaolinite (%)	Chlorite (%)	Smectite (%)	Plagioclase (%)	K-feldspar (%)	Calcite (%)	Ankerite (%)	Siderite (%)	Barite (%)
X1-1	X1	1868.1	66.0	20.2	0.0	0.2	1.9	5.3	0	2.7	0	0	3.7
X1-2	X1	1877.5	57.8	19.5	0.0	0.9	1.8	13.7	0	2.7	0	0	3.6
X1-3	X1	1878.52	52.1	14.7	0.0	1.2	1.3	12.9	0	1.2	0	12.2	4.4
X1-4	X1	1970	48.0	22.2	1.4	3.0	0.7	9.1	0	5.7	0	5.7	4.2
X1-5	X1	1995	41.4	21.3	1.3	4.0	1.8	3.1	2.2	0	8.2	9.8	6.9
X1-6	X1	2056	48.5	14.8	0.7	1.8	0.5	16	2.3	6.5	1.7	4.2	3
X2-1	X2	1548.02	69.3	8.1	0.0	0.4	0.7	11.7	0	0	0	5.5	4.3
X2-2	X2	1552.53	52.8	19.4	0.0	0.4	1.1	13	0	3	0	6.5	3.8
X2-3	X2	1553.86	44.4	34.0	0.0	1.7	6.4	6.7	0	0	0	3.5	3.3
X2-4	X2	1557.15	50.4	28.0	0.0	0.0	2.1	11.6	0	1.7	0	3.1	3.1
X2-5	X2	1559.14	56.3	23.8	0.0	1.6	0.9	12.2	0	1.8	0	0	3.4
X2-6	X2	1629.68	62.5	9.8	0.0	1.7	0.8	19.1	0	2.5	0	0	3.6
X2-7	X2	1631.73	52.6	10.4	0.0	1.8	1.0	14.2	0	8.3	0	5.2	6.5
X2-8	X2	1636.75	69.3	7.3	0.0	1.7	0.3	11.7	0	0	0	5.5	4.2
X3-1	X3	1595	85.7	5.0	2.8	0.0	0.3	0	0	0	0	0	6.2
X3-2	X3	1597.1	88.6	2.2	1.7	0.0	0.1	0	0	0	0	0	7.4
X3-3	X3	1598.3	86.9	3.2	2.8	0.0	0.2	0	0	0	0	0	6.9
X3-4	X3	1598.5	89.1	3.2	2.3	0.0	0.2	0	0	0	0	0	5.2