Modelling Degradation Time of Hydroxyethyl Cellulose-Based Polymeric Fluids

Abstract Sand production from hydrocarbon wells is known not to have any economic value. Hydroxyethyl cellulose is one of the polymers of choice used to formulate gravel carrier fluids used to transport proppants to the desired intervals in hydrocarbon wells, drilled in unconsolidated formations, to stop or minimize sand production. Viscous polymeric fluids must be degraded to ensure good wellbore cleanout and good hydrocarbon production. Polymer Degradation is a function of several variables such as temperature, pH, salinity, type and concentration of gel breakers and polymers. The success of gravel pack operations in the field depends greatly on the fluid design, which must first be qualified in the laboratory. It is often difficult to predict the degradation time of polymer fluids used in gravel pack operations because it’s a function of many variables. Therefore, in this study, a more detailed study of the effect of temperature, sodium persulfate breaker concentration and hydroxyethyl cellulose polymer concentration were performed. A model equation, capable of predicting the break time of hydroxyethyl cellulose-based polymeric fluid mixed in 2% by weight of potassium chloride brine, at various temperatures for different concentrations of sodium persulfate breaker, was developed based on data from laboratory experiments with the aid of Mini tab 17 software using factorial regression analysis. From the analysis, temperature has the highest impact on the degradation rate of hydroxyethyl cellulose with an effect estimate of -281.7, while breaker concentration and polymer concentration have an effect estimate of -113.4 and 128.8 respectively. From the analysis of variance, the coefficient of determination, R Squared, was 0.8792. The process of degradation of hydroxyethyl cellulose-based fluid similar composition can be more easily and faster optimized using this model.