Experiments on injectivity and profile control performance of pre-crosslinked gel particles widely used in oilfields were done. The results show that the injectivity of pre-crosslinked gel particle is poor. Most of particles pile up in the front of sand pack, and the migration distance of pre-crosslinked gel particles is less than 20 cm, which lead to the formation of filter cake and the poor effects of depth profile control. The injection of pre-crosslinked gel particle is selectivity. In the early stage of profile control, the diversion rate of low permeability layer increases slightly, and the effect is less than 2%. After long-term waterflooding, due to the easily breakthrough in higher permeability layers, the diversion rate of low permeability layer declines in comparison that before the operation. It is indicated that pre-crosslinked gel particles will harm low permeability layers. It is calculated and analyzed that the diameters of current pre-crosslinked gel particles are bigger than pore size. Theoretically, current pre-crosslinked gel particles are difficult to be applied in depth profile control.

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Pre-crosslinked gel particle,   , Profile control and water shut-off,   ,  Particles diameter,   ,  Pore size