Polymer Flow in Porous Media

Abstract

Polymer flooding is one of the most successful chemical EOR methods, and is primarily implemented to accelerate oil production by sweep improvement. However, other benefits have extended the utility of polymers. During the last decade, it has been evaluated for an increasing number of fields, both offshore and onshore. This is a consequence of improved polymer properties, which extends the use to HTHS (high temperature high salinity) conditions and of improved understanding of flow mechanisms such as for heavy oil mobilization. A key issue in understanding polymer performance is to control and predict in-situ porous medium rheology. The first part of this paper reviews recent developments in understanding polymer flow in porous medium. Especially, polymer in-situ rheology and injectivity is discussed. The second part of this paper reports polymer flow experiments using the most applied polymer for EOR processes, HPAM (partially hydrolyzed polyacrylamide). The experiments address high rate near-wellbore behavior (radial flow) as well as reservoir rate steady state flow (linear flow) and discuss differences observed in terms of flow conditions. In addition, impact of oil on polymer rheology was investigated, and compared to single-phase polymer flow in Bentheimer sandstone rock material. Presence of oil leads to a reduction in apparent viscosity.

Hydrophobically associating polymers for enhanced oil recovery – Part B: A review of modelling approach to flow in porous media

“…However, the flow of associating polymers measured with viscometers/rheometers differs significantly from what is experienced in a porous media. According to Skauge et al (2018), the rheology of polymers as measured with these instruments differs from what is obtained in a porous media; the reasons for this include the following:…”

“…A local maximum for the polymer viscosity is obtained at a third critical rate . Beyond , there is another decrease in polymer viscosity; this shear rate is characterized as the onset of mechanical degradation (Dupas et al, 2012;Brakstad and Rosenkilde, 2016;Lohne et al, 2017;Skauge et al, 2018). Polymer injectivity in porous media is influenced by a number of factors including shear thickening.…”

“…However, flow in rheometers or viscometers represents a different geometrical configuration to a porous media. The flow of polymers in a porous media can be attributed to the existence of both shear and extensional components (Sochi, 2010;Stavland et al, 2010;Zamani et al, 2015;Lohne et al, 2017;Zamani, et al, 2017;Skauge et al, 2018). In differentiating between these components, Figure 2 shows a fluid element (A) subjected to both shear and extensional flow.…”

“…Therefore, a fluid element is in extensional or elongational flow when it is subjected to extensions or compressions which dominates over shear effects. In like manner, Skauge et al (2018) used the coil-stretch model to explain the phenomenon of polymer extensional flow. Polymer molecules can be visualized as entangled coils and when subjected to flow, two competing forces arise.…”

Comprehensive analysis of the atenolol – DNA complex by viscometric, molecular docking and spectroscopic techniques

“…The intercalation process results in an increase in distance between base pairs that Abbreviations: Atenolol, ATN; Alizarin, ALZ; deoxyribose nucleic acid, DNA; Supporting Information, SI results in local unwinding of DNA. [21,22] The intercalated molecules are generally less exposed to the external environment compared with other molecules that interplay through grove binding or electrostatic interaction. [23] The use of drugs in the form of antibiotics, anticancer, antihypertensive, antidiabetic agents, or analgesics for human use has increased due to current lifestyles.…”