Reservoir Sensitivity Analysis of Tight Sandstone and Its Controlling Factors: A Case Study from Chang 4+5 to Chang 6 Reservoirs in N 212 Well Block of Nanniwan Oilfield, Ordos Basin

Table 2

Statistics of dynamic core flow tests for velocity sensitivity of samples from Chang 4+5 and Chang 6 reservoirs of N 212 well block.

Sample number	Depth (m)	Stratum	Lc (cm)	Dc (cm)	Kg (×10^-3 μm^2)	Φ (%)	Critical velocity (mL/min)			Rank
S2	692.59	Chang 4+5	3.82	2.49	0.0439	10.03	0.02	47.4	0.474	Moderate-weak
S5	702.39		3.81	2.50	0.642	9.30	0.02	45.6	0.456	Moderate-weak
S31	767.00	Chang 6	3.84	2.49	0.0325	4.86	0.02	45.2	0.452	Moderate-weak
S38	778.92		3.91	2.50	0.208	8.26	0.2	42.6	0.426	Moderate-weak
S40	791.77		3.81	2.50	0.265	8.12	0.2	44.0	0.44	Moderate-weak
S41	760.99		3.89	2.49	0.291	9.08	0.25	42.7	0.427	Moderate-weak