Polymer rheology in porous media

The results of a number of studies on polymer rheology in porous media are then reviewed. Firstly, results for pseudoplastic fluids (mainly xanthan) are discussed and then results are reviewed for fluids showing some viscoelastic/extensional viscosity behaviour (e.g. HPAM, PEO). In all of these studies, flow is purely single-phase, and most experiments have been performed at 100% water saturation in the porous pack or core, although a few have been done at residual oil. 

There is an interesting analogy between understanding normal two-phase (oil/water) flow in porous media and the understanding of the in-situ rheology 

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POLYMER RHEOLOGY IN POROUS MEDIA Straight. All the above models lead to results of the form ... 

POLYMER RHEOLOGY IN POROUS MEDIA 6.3.2 Xanthan in-situ rheology pseudoplastic behaviour... 

Theoretical analysis of polymer rheology in porous media... 

Measurement and Impact Factors of Polymer Rheology in Porous Media... 

This chapter presents the fundamental terms/concepts used to characterize polymer rheology behaviors, the mathematical models that are used to calculate shear rate, the experimental procedures to measure polymer rheology in porous media, and the factors that impact the in situ rheology of polymers. 

The polymer rheology in porous media is often measured by coreflooding experiments. Figure 1 shows a typical coreflooding apparatus. It is mainly composed of a pump used for pumping distilled water, piston accumulator used for polymer storage, core holder or sandpack, and pressure gauge or transducer to record injection pressure. 

For applications in which enhanced-oU-recovery (EOR) polymer solutions are injected, we estimate injectivity losses (relative to water injectivity) if fractures are not open. We also consider the degree of fracture extension that may occur if fractures are open. Three principal EOR polymer properties are examined that affect injectivity (1) dehris in the polymer, (2) polymer rheology in porous media, and (3) polymer mechanical degradation. An improved test was developed to measure the tendency of EOR polymers to plug porous media. The new test demonstrated that plugging tendencies varied considerably among both partially hydrolyzed polyacrylamide (UPAM) and xanthan polymers. 

This paper examined the three principal EOR polymer properties that affect injectivity (1) debris in the polymer, (2) polymer rheology in porous media, and (3) polymer mechanical degradation. We also examined the impact of fractures on polymer solution injectivity. 

Seright, R.S., Fan, T., and Wavrik, K., and de Carvalho Balaban, R. 2010. New Insights Into Polymer Rheology in Porous Media. Paper SPE 129200 presented at the SPE Improved Oil Recovery Symposium, Tulsa, 24-28 April. DPI 10.2118/129200-MS. 

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