Experimental Study on Blockage Mechanism and Blockage Locations for Polymer-Flooded Reservoirs in the Henan Oilfield

Figure 20

NMR T2 distribution spectra.

(a) NMR T2 distribution spectra before and after polymer injection into Shuang K7-145-21 core from Shuanghe North Block

(b) NMR T2 distribution spectra before and after polymer injection into Shuang K431-6 core from Shuanghe North Block

(c) NMR T2 distribution spectra before and after polymer injection into Shuang K7-145-7 core from Shuanghe North Block