Water-in-oil emulsions have been developed which have been shown to be a credible means of deploying scale inhibitors in a non-aqueous medium. Furthermore, the use of slowly degrading emulsion systems provides a means of trapping scale inhibitor within porous media and allowing subsequent controlled release of the chemical. This has been demonstrated using sandpack and coreflood experiments where the lifetime of the inhibitor, as measured by pore volumes of brine eluted to a given inhibitor concentration, has been extended by up to (and possibly beyond) four times compared with the base case non-emulsified product. No permeability damage has been observed for the emulsion systems. The use of emulsion droplets to provide chemical reservoirs within the formation also considerably reduces the wastage of non-retained chemical observed with conventional squeeze treatments. The non-aqueous nature of the emulsion system potentially allows ingress of the scale inhibitor into parts of the reservoir normally denied access to an aqueous-based formulation and so can improve contact between the scale inhibitor and the reservoir fluids on production. Furthermore, the whole treatment can be non-aqueous allowing oil continuity to be maintained during the treatment affording rapid well clean up post treatment.

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