<p>A new use of polyaspartate is described for reducing particle migration in rock formations. The use of polyaspartate has beneficial effects in oil wells, where particle migration is responsible for blocking of pores in rock formations and consequent losses in productivity. Also disclosed is a method of treating a rock formation by well intervention, characterised in that the rock formation is contacted with a dispersion of a polyaminoacid prior to, or simultaneously with, the well intervention. The method reduces the amount of particle migration during well intervention.</p>
