초록 ▼

A method for removing filtercake from a subterranean borehole comprising drilling the borehole with a drilling fluid that includes additives to form a filtercake having an oxidation-degradable component, preferably a polysaccharide. The filtercake is contacted with a clear brine containing bromine o

A method for removing filtercake from a subterranean borehole comprising drilling the borehole with a drilling fluid that includes additives to form a filtercake having an oxidation-degradable component, preferably a polysaccharide. The filtercake is contacted with a clear brine containing bromine or bromate generating agents to degrade the polymers within the filtercake. The brine contains bromide salts and an oxidant capable of delayed oxidation of the bromide to bromine at downhole conditions.

대표청구항 ▼

[ What is claimed is:] [1.] A method for preparing a borehole in the earth to produce hydrocarbons therefrom, comprising:drilling the borehole while circulating a mud therein which comprises a polysaccharide and optionally comprises finely divided solids dispersed therein to form a filtercake on sur

[ What is claimed is:] [1.] A method for preparing a borehole in the earth to produce hydrocarbons therefrom, comprising:drilling the borehole while circulating a mud therein which comprises a polysaccharide and optionally comprises finely divided solids dispersed therein to form a filtercake on surfaces of the borehole essentially free of oxidants and bromine and bromate generating agents; andintroducing a filtercake removal fluid in the wellbore, in contact with a subterranean formation containing the hydrocarbons to be produced, for a duration effective to substantially remove the filtercake in the vicinity of the subterranean formation, wherein the filtercake removal fluid comprises a clear brine comprising a halide salt having a density of at least 1.08 g/cm.sup.3 (9 lb/gal) and a bromine or bromate generating agent dissolved in the brine.