Thermal gelation of partially hydrolysed polyacrylamide/polyethyleneimine mixtures using design of experiments approach

Publication date: Available online 8 October 2019Source: Materials Today CommunicationsAuthor(s): Mohammed Abdelfetah Ghriga, Mahdi Hasanzadeh, Mourad Gareche, Seif El Islam Lebouachera, Nadjib Drouiche, Bruno GrasslAbstractPolyethyleneimine crosslinked polymer gels are gaining a huge interest in conformance control applications in oilfields. They are used to reduce the production of undesirable fluids (water & gas) by blocking the fractures that connect injection and production wells. In this paper, a statistical analysis on the thermal gelation of well characterized reactants namely partially hydrolysed polyacrylamide (PHPA) (Mw = 5.1 million Daltons and hydrolysis degree = 6%) and polyethylenimine (PEI) (Mw = 19.2 kilo Daltons and branching degree = 59%), was conducted using response surface methodology (RSM). A four factor doehlert matrix was employed in designing the experiments and evaluating the gelation time as function of salinity (0 to 8 g/L NaCl), polymer (PHPA) and crosslinker (PEI) concentrations, temperature (70 °C to 90 °C) and their corresponding combinations. As a result, the gelation time was found to strongly vary with salinity, temperature and PHPA concentration following a nonlinear mathematical model. The analysis of variance (ANOVA) of this model revealed its significance in a 95% confidence level against experimental data. In a second part, an experimental investigation was carried out to understand the interaction between PHP...
Source: Materials Today Communications - Category: Materials Science Source Type: research