DRILLING FLUIDS BASED ON A MIXTURE OF A SULFONATED THERMOPLASTIC POLYMER AND AN AMINE-TREATED CLAY

摘要

The present invention relates to mixtures of sulfonated thermoplastic polymers and amine-treated clays which function as viscosification agents when added to oil-based drilling muds which are the fluids used to maintain pressure, cool drill bits and lift cuttings from the holes in the drilling operation for oil and gas wells. The sulfonated thermoplastic polymers have 5 to 100 meq. of sulfonate groups per 100 grams of the sulfonated thermoplastic polymer, wherein the sulfonated groups are neutralized with a metallic cation or an amine or ammonium counterion. A polar cosolvent can optionally be added to the mixture of oil drilling mud and sulfonated thermoplastic polymer, wherein the polar cosolvent increases the solubility of the sulfonated thermoplastic polymer in the oil drilling mud by decreasing the strong ionic interactions between the sulfonate groups of the sulfonated polymer.