Abstract
Several polymer formulations were prepared and they have been characterized for their physical and chemical properties with viscosities ranging from 14 cP to 418 cP for concentrated solutions and from 3.5 cP to 15.8 cP for diluted solutions when measured at 80°C. Several polymer formulations met the critical test of stability when sand cores were immersed in 3% KCl brine stored at 80°C for over 1000 hrs. Also several formulations gave very significant improvement in the compressive strength of the treated sands that exceeded the minimum compressive strength of 10 Kg/cm2 by a factor of two to three. The safe compressive strength of oil producing well formation is reported to be about 10 kg/cm2 in order to have a stable formation that sustains shear bands. These polymeric compositions were also tested on Kuwait dune sands and actual oil well formation sand of Minagish oil well MN-117 in Kuwait. Results show that compressive strength values of three to several folds of the recommended values for oil formation were realized. Values of 35-100 kg/cm2 were achieved from this work. Improving compressive strength of weak and friable formation is one of the three main requirements for a successful sand consolidation treatment. Core flooding test on sandpacks made from dune sand and Minagish well MN-117 sand show that all polymer compositions developed compressive strengths in the treated sandpacks that far exceeded the minimum requirement of 10 Kg/cm2 and gave complete water shutoff to water production. Finally higher temperatures required higher doses of these compositions where 1.0 PV, 0.4 PV and 0.25 PV of these polymers were needed to produce the desired compressive strength at 110°C, 80°C and 60°C respectively.
