Investigation on matching relationship and plugging mechanism of self-adaptive micro-gel (SMG) as a profile control and oil displacement agent

Heterogeneity is well known to reduce sweep efficiency during oil development processes. Self-adaptive micro gel (SMG) as a agent for in-depth profile control is significantly limited to strict matching between complicated pore structure and particle size. A new matching factor considering size and distribution of particle and pore is presented to study the relationship of SMG and cores. The resistance coefficient and plugging rate indicate that it will get the greatest plugging effect when matching factor ranges from 1 to 1.3. Long cores with multiple pressure points and Dual-tube parallel flooding experiments shows that SMG can significantly reduce the water cut and obtain the best oil recovery efficiency when the high permeability layer within the matching factor range. According to the number and relative size to pore throats of SMG, microfluidic experiments show that plugging can be divided into direct plugging, bridging plugging, superimposed plugging and hydrodynamic plugging. (C) 2020 Published by Elsevier B.V.