Numerical Simulation of Time-Varying Characteristics in a High-Permeability Sandstone Reservoir: A Case of Gaoqian Southern Area

Table 4

Changes of clay mineral contents before and after water flooding.

Lithofacies	Displacement stage	Overall amount (%)	Rate of change	S (%)	Rate of change	I/S	Rate of change	I (%)	Rate of change	K (%)	Rate of change	C (%)	Rate of change
Fine sandstone facies	Before water flooding	20.0	-43.3	6.8	-47.0	6.2	-37.1	1.2	-62.0	4.4	-29.0	1.4	-82.5
	After water flooding	11.3		3.6		3.9		0.5		3.1		0.2
Middle sandstone facies	Before water flooding	14.6	-31.8	7.2	-21.1	0.0	/	1.5	-88.4	4.7	-42.5	1.2	15.0
	After water flooding	10.0		5.7		0.0		0.2		2.7		1.4

S: smectite; I: illite; K: kaolinite; C: clay.