Synthesis And Characterisation Of Polymeric Additifs And Their Application In Drilling Muds

Acrylamide (AM) was grafted onto starch via a free radical polymerization. The number of grafting sites and the length of the grafted chains were varied by varying initiator and monomer concentration. The copolymers obtained were characterized using FTIR and viscometric methods. The IR spectra of the copolymer confirmed the presence of a band (1670 cm- 1) due to the amide group of polyacrylamide. The intrinsic viscosity was found to increase with the increase in monomer concentration and to decrease with the increase in initiator concentration. A concentration of 2.10-4 mol of initiator was found to give the highest intrinsic viscosity. The rheological studies of polymer solutions indicated that the viscosity loss of the copolymer with time and salts was very small (less than 8%). Water solubility was found to increase with the increase in the polyacrylamide side chain length. The filtrate volume of the mud was reduced with the increase in the copolymer concentration before or after the thermal aging test. The rheological properties of the mud were not greatly affected by the copolymer concentration, an essential characteristic of filtrate reducers. The comparison between two synthesized copolymers and a commercial one namely polyanionic cellulose (PAC) indicated that the three polymers are very effective filtrate reducers