A delayed gelation elastic silicic acid gel water plugging agent and its performance
The silicic acid gel water plugging agent often has short gelation time and high brittleness after gelation.To address this issue,a delayed gelation elastic silicic acid gel water plugging agent was devel-oped in combination with the reservoir conditions of L oilfield,the type and dosage of activator,the type and dosage of elasticity improver,and the effect of sodium silicate dosage on gelation time and elastic modulus were examined.The injectivity and plugging ability of the plugging agent were evaluated using a sand-filled tube experiment.The results showed that the optimal formulation was:6％sodium silicate,0.85％activator ternary weak acid monoammonium GL-1 and 0.1％elasticity improver mixed meter hy-droxide.At the reservoir temperature of 65 ℃,the gelation strength reaches grade E after 72 h,and the e-lastic modulus after gelation was 589.46 Pa.The highest injection pressure for injecting 0.8 PV was only 0.72 MPa in the sand-filled tube with permeability of 1 168.06×10-3～5 061.57×10-3μm2,and the plugging rate was more than 96％.This study suggests that the water plugging agent had good injectivity and plugging ability and could be used for the L oilfield.
oil well pluggingdelayed gelationsilicic acid gelwater plugging agentinjectivity and plugging capacity
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