Patent ID: 8393395
Filing Date: 2013-03-12
Classification: C09K

Abstract:
1. A process for hydraulic fracturing of a subterranean reservoir formation penetrated by a wellbore, comprising preparing an emulsion with an aqueous continuous phase and a disperse phase which comprises an oilfield chemical and a solution of a water-insoluble carrier matrix material in an organic solvent, evaporating the organic solvent while agitating the emulsion, forming particles which each comprise an oilfield chemical distributed as multiple particles enclosed within a particle of a water-insoluble carrier matrix material, pumping an aqueous suspension of the particles of the carrier matrix material-from the surface via the wellbore and into the reservoir, wherein the carrier matrix material is an organic polymer which has a Tg above 40° C. but below the temperature of the reservoir so as to provide a delayed release of the oilfield chemical from the particles into surrounding fluid through increase in permeability of the matrix upon temperature rise within the reservoir to a temperature above Tg of the matrix, such that the oilfield chemical is liberated from the particles after they have entered the fracture.