IMPROVED METHOD AND CHEMICAL AGENT FOR REDUCTION OF WATER PRODUCTION FROM OIL AND GAS CONTAINING WELLS

摘要

The invention relates to a chemical substance (200) for reducing water production from subterranean zones surrounding oil and gas wells after being inserted into the formation, the chemical substance (200) comprising a plurality of particles (210), wherein each particle (210) has a water-swellable core (220). Each core (220) has been coated with a flexible coating layer (230) which is hydrophobic under all circumstances in the well and which does not swell in the presence of water nor react with water. Furthermore, the flexible coating layers from different particles contacting each other, have the property of forming an interconnected hydrophobic network (or pathway) of "channels", at least in a swollen condition of the core, for allowing hydrocarbons to go through this hydrophobic network/pathway while simultaneously preventing water (hydrophilic) to go through the "channels".