Influence of rock pores on gel-forming of amphion polymer gel

Key words:  amphion polymer gel  rock pore  compatibility  intra-molecular cross-linked  end effect  dynamic gelling

Abstract:

The Bush viscometer, dynamic light scattering, and core flow experiment were used to study the gelling effect of cross-linked polymer systems in the jar and porous media, and the compatibility of the system and the core. The results show that the viscosity of the system increases greatly, and the molecular coil dimensions of the system increases clearly, which indicates the gelling effect of the system is good. And the intra-molecular cross-linked of the system takes place firstly, and then the inter-molecular cross-linked. When a wide range of inter-molecular cross-linked reaction does not take place in the system, the molecular clew size is smaller, and has good compatibility with the core. However, when the cross-linked reaction takes place, the compatibility obviously deteriorates (the molecular clew size increases significantly), which results in the difficulty of injecting the core. Under static conditions, cross-linked polymer system could gel in the core, but the gelling effect is significantly lower than that of the beaker. And with the time increasing, the residual resistance coefficients of the inter-molecular cross-linked system first increases, then decreases. And with the core permeability increasing, the residual resistance coefficient of the cross-linked polymer systems increases, which shows the increase of time and space can improve the gelling effect of the cross-linked polymer systems. Under dynamic conditions, the resistance coefficient of the cross-linked system and the polymer solution are almost the same, which means that the cross-linked reaction of such cross-linked polymer system can not occurr. The shift rate and locating ability of polymer and cross-linker in cross-linked polymer system can be disturbed with the flow of the system, which leads to the decrease of the gelatin rate, the reduction of the cross-linking degree, or even the elimination of the gel formation.