Monitoring Thermal and Mechanical Stability of Enhanced Oil Recovery (EOR) Acrylamide Based Polymers (PAM) Through Intrinsic Viscosity (IV) Determination Using a New Capillary Rheology Technique

摘要: Chemical EOR polymers are in general anionic, synthetic, acrylamide based co-and ter-polymers. Those provide viscosity to water system thanks their high molecular weight (Mw) and the repulsions between ionic charges. Uncoiling entanglements two mechanisms linked Mw repulsion. When a polymer is injected, different will act on its chemical structure by chemical, mechanical, thermal, free radical modifications. The understanding of resulting rheological properties modified PAM very important since it can change control over mobility ratio when propagates downhole reservoir. Various lab experiments be performed predict those changes time. In particular, intrinsic convenient way reaching dimension macromolecule given solvent at temperature but time consuming. this publication, new efficient capillary rheology technique presented allowing measuring bulk solution various brines even (140° C) controlled low shear rate. It thus possible access dilute solutions under conditions that, our knowledge, cannot viscometers commercially available. involves specific set up including pressure transducers. allows monitoring effect thermal modifications after ageing times. performances were determined terms accuracy, acquisition compositions molar masses (104-106 g/mol) used for calibration purposes. was then applied investigate behavior industrial (M>106g/mol) EOR: A sodium acrylamido-Tertiary-butyl sulfonate (ATBS) (SPAM), terpolymer with ATBS, N-vinylpyrrolidone (NVP) (PAM called SAV). Rheological viscosities rates 8 800 s-1, 25, 85 140°C, salinities (20,000 240,000 TDS). addition, mechanical stability evaluated injection internal diameter (125μm), rate 1,500,000s-1. results obtained using an reliable selecting proper chemistry reservoir condition. Ultimately, defines salinity, domains where PAM, SPAM or SAV stable. automated, made transportable devices, anaerobic provides fast following property Copyright 2016, Society Petroleum Engineers.