Hydrophobically modified carboxymethylcellulose: additive for aqueous drilling fluids under low and high temperature conditions

The use of additives from renewable sources in drilling fluids has received special attention due to crescent environmental regulations. At the same time, increasing demand for energy sources stimulates the search for products that can withstand severe perforation conditions. In this scenario, this work aimed at the chemical modification of a polysaccharide, carboxymethylcellulose (CMC), through insertion of hydrophobic groups of dodecylamine (DDA), and its investigation as an additive in aqueous fluids. The performance was evaluated via rheological and filtration standards measurements in oil industry for low and high temperature reservoirs. Rheological parameters did not change significantly either with aging or with temperature of data acquisition. Fluid with CMC exhibited higher filtrate volume than the corresponding CMC–DDA for all conditions studied. In the presence of CMC, the filtrate volume increased after aging under low (10% of increase) and high (69.2% of increase) temperature and pressure. On the other hand, CMC–DDA provided more controlled filtration after aging at low (8.3% of reduction) and high (only 25.9% of increase) temperature and pressure. This behavior indicates that CMC–DDA is a promising additive to control the filtration of aqueous drilling fluids at different reservoir conditions.