Damage Mechanism of Oil-Based Drilling Fluid Flow in Seepage Channels for Fractured Tight Sandstone Gas Reservoirs

Table 8

Evaluation of water-phase alkali sensitivity.

Core number	Permeability at different pH values (10^-3 μm^2)				Permeability recovery rate (%)	Damage degree
	7.0	9.0	11.0	13.0
125	44.03	30.31	13.87	8.92	20.25	Serious
133	65.30	51.31	31.29	6.85	10.49	Serious