PROCESS FOR BREAKING THE VISCOSITY OF POLYMER-THICKENED AQUEOUS SYSTEMS FOR MINERAL OIL AND NATURAL GAS EXTRACTION

摘要

A novel process is proposed for breaking the viscosity of an aqueous phase thickened with preferably hydrophilic polymers in the exploration and production of mineral oil and/or natural gas. For this purpose, the breakage is performed via the formation of a mobile emulsion with water as the continuous phase, this emulsion being formed by the addition of at least one surface-active component to a system which consists of the thickened flush and an oil phase, which comprises crude oil present in a deposit and/or an oil introduced into a deposit. The preferred surface-active components used are solubilizers between oil and water phase, and especially nonionic surfactants, cationic surfactants and/or amphoteric surfactants. In addition to the surface-active component, it is possible to use further components, which are demulsifiers, nonemulsifiers, cosurfactants or modifying agents for the surface tension. With the aid of this process, in the simultaneous presence of an oil phase, the aqueous phase as a mobile system is displaced and finally discharged to the surface, which is associated with extremely effective cleaning of the borehole. It is possible to completely dispense with the use of chemicals with regard to economic viability and from environmental points of view.