POLYACRYLAMIDE HYDROGELS WITH A DISPERSED FILLER: SPECIFICS OF RHEOLOGY AND FILTRATION IN FRACTURES

In using fl ow diversion and water shutoff technologies, the most widely used sealing compounds are polyacrylamide solutions crosslinked with Cr³⁺ ions. To achieve high technological effi ciency, it is necessary to retain structural and mechanical properties of a sealing compound. Earlier, we proposed a hydrogel made up of sodium silicate and polyacrylamide crosslinked by chromium acetate which has good rheological characteristics and high residual resistance factors during fi ltration in fractures. It is noted that the addition of a dispersed fi ller increases substantially the composition effi ciency. In this investigation, a study has been made of the rheology of hydrogels on the basis of sodium silicate, polyacrylamide, and chromium acetate with a dispersed fi ller (rice husk) in fi ltration through a model of an ideal fracture of various degree of openness. It has been established that the addition of a dispersed fi ller increases substantially the strength of water shutoff screen after fi ltration in fractures. In this case, there is almost no mechanical destruction of hydrogel with a fi ller in large fractures. For comparison investigations with hydrogel on the basis of polyacrylamide, resorcinol, and paraform were conducted. It is shown that after fi ltration in fractures, hydrogels on the basis of polyacrylamide, resorcinol, and paraform do not experience, in practice, any mechanochemical destruction. The experimental results indicate that the introduction of dispersed materials into hydrogels for water shutoff of fractured reservoirs increase signifi cantly the technological effi ciency of processes by decreasing the mechanical destruction and increasing the residual resistance factor.
   
Author:  A. G. Telin, V. A. Strizhnev, A. V. Fakhreeva, R. R. Asadullin, L. E. Lenchenkova, A. A. Ratner, V. S. Chepenko
Keywords:  water shutoff in fractured reservoirs, polyacrylamide hydrogels, rheological investigations, ideal fracture model, fi ltration, mechanochemical destruction, composite sealing compounds
Page:  515