Unexpected scaling of interstitial velocities with permeability due to polymer retention in porous media

2021 ◽  
Vol 6 (8) ◽  
Author(s):  
Shima Parsa ◽  
Ahmad Zareei ◽  
Enric Santanach-Carreras ◽  
Eliza J. Morris ◽  
Ariel Amir ◽  
...  
Keyword(s):  
Porous Media ◽  
Polymer Retention

Chemical EOR in Low Permeability Sandstone Reservoirs: Impact of Clay Content on the Transport of Polymer and Surfactant

2021 ◽  
Author(s):  
Imane Guetni ◽  
Claire Marlière ◽  
David Rousseau
Keyword(s):  
Porous Media ◽  
Specific Surface ◽  
Surface Area ◽  
Specific Surface Area ◽  
Clay Content ◽  
Low Permeability ◽  
Depth Propagation ◽  
The Impact ◽  
Polymer Retention ◽  
Injection Strategies

Abstract Application of chemical enhanced oil recovery (C-EOR) processes to low-permeability sandstone reservoirs (in the 10-100 mD range) can be very challenging as strong retention and difficult in-depth propagation of polymer and surfactant can occur. Transport properties of C-EOR chemicals are particularly related to porous media mineralogy (clay content). The present experimental study aimed at identifying base mechanisms and providing general recommendations to design economically viable C-EOR injection strategies in low permeability clayey reservoirs. Polymer and surfactant injection corefloods were conducted using granular packs (quartz and clay mixtures) with similar petrophysical characteristics (permeability 70-130 mD) but having various mineralogical compositions (pure quartz sand, sand with 8 wt-% kaolinite and sand with 8 wt-% smectite). The granular packs were carefully characterized in terms of structure (SEM) and specific surface area (BET). The main observables from the coreflood tests were the resistance and residual resistance factors generated during the chemical injections, the irreversible polymer retention and the surfactant retention in various injection scenarios (polymer alone, surfactant alone, polymer and surfactant). A first, the impact of the clay contents on the retention of polymer and surfactant considered independently was examined. Coreflood results have shown that retention per unit mass of rock strongly increased in presence of both kaolinite and smectite, but not in the same way for both chemicals. For polymer, retention was about twice higher with kaolinite than with smectite, despite the fact that the measured specific surface area of the kaolinite was about 5 times less than that of the smectite. Conversely, for surfactant, retention was much higher with smectite than with kaolinite. Secondly, the impact of the presence of surfactant on the polymer in-depth propagation and retention was investigated in pure quartz and kaolinite-bearing porous media. In both mineralogies, the resistance factor quickly stabilized when polymer was injected alone whereas injection of larger solution volumes was required to reach stabilization when surfactant was present. In pure quartz, polymer retention was shown, surprisingly, to be one order of magnitude higher in presence of surfactant whereas with kaolinite, surfactant did not impact polymer retention. The results can be interpreted by considering adsorption-governed retention. The mechanistic pictures being that (a) large polymer macromolecules are not able to penetrate the porosity of smectite aggregates, whereas surfactant molecules can, and (b) that surfactant and polymer mixed adsorbed layers can be formed on surfaces with limited affinity for polymer. Overall, this study shows that C-EOR can be applied in low permeability reservoirs but that successful injection strategies will strongly depend on mineralogy.

scholarly journals An Overview on Polymer Retention in Porous Media

Energies ◽  
2018 ◽  
Vol 11 (10) ◽  
pp. 2751 ◽  
Author(s):  
Sameer Al-Hajri ◽  
Syed Mahmood ◽  
Hesham Abdulelah ◽  
Saeed Akbari
Keyword(s):  
Porous Media ◽  
Enhanced Oil Recovery ◽  
Oil Recovery ◽  
Polymer Flooding ◽  
Mobility Ratio ◽  
Reservoir Rock ◽  
Polymer Molecules ◽  
Modeling Techniques ◽  
Proper Estimation ◽  
Polymer Retention

Polymer flooding is an important enhanced oil recovery technology introduced in field projects since the late 1960s. The key to a successful polymer flood project depends upon proper estimation of polymer retention. The aims of this paper are twofold. First, to show the mechanism of polymer flooding and how this mechanism is affected by polymer retention. Based on the literature, the mobility ratio significantly increases as a result of the interactions between the injected polymer molecules and the reservoir rock. Secondly, to provide a better understanding of the polymer retention, we discussed polymer retention types, mechanisms, factors promoting or inhibiting polymer retention, methods and modeling techniques used for estimating polymer retention.

Some Aspects of Polymer Retention in Porous Media Using a C14-Tagged Hydrolyzed Polyacrylamide

1975 ◽  
Vol 15 (04) ◽  
pp. 323-337 ◽  
Author(s):  
M.T. Szabo
Keyword(s):  
Porous Media ◽  
Oil Recovery ◽  
Pore Volume ◽  
Produced Water ◽  
Polymer Concentration ◽  
Oil Saturation ◽  
Polymer Flow ◽  
Hydrolyzed Polyacrylamide ◽  
Polymer Retention ◽  
Inaccessible Pore Volume

Abstract Numerous single-phase flow and oil-recovery tests were carried out in unconsolidated sands and Berea sandstone cores using C14-tagged, hydrolyzed polyacrylamide solutions. The polymer-retention polyacrylamide solutions. The polymer-retention data from these flow tests are compared with data obtained from static adsorption tests. Polymer concentrations in produced water in Polymer-flooding tests were studied using various Polymer-flooding tests were studied using various polymer concentrations, slug sizes, salt polymer concentrations, slug sizes, salt concentrations, and different permeability sands. Results show that polymer retention by mechanical entrapment had a dominant role in determining the total polymer retention in short sand packs. However, the role of mechanical entrapment was less in the large-surface-area Berea cores. In oil-recovery tests, high polymer concentrations were noted at water breakthrough in sand-pack experiments, an indication that the irreducible water was not displaced effectively ahead of the polymer slug. However, in similar tests with Berea cores, a denuded zone developed at the leading edge of the polymer slug. polymer slug. The existence of inaccessible pore volume to polymer flow is shown both in sand packs and in polymer flow is shown both in sand packs and in sandstone cores. Absolute polymer-retention values show an almost linear dependency on polymer concentration. The effect of polymer slug size on absolute polymer retention is also discussed. Distribution of retained polymer in sand packs showed an exponential decline with distance. The "dynamic polymer-retention" values in short sand packs showed much higher vales than the ‘static packs showed much higher vales than the’ static polymer-adsorption" values caused by mechanical polymer-adsorption" values caused by mechanical entrapment. The mechanism of polymer retention in silica sands and sandstones is described, based on the observed phenomenon. Introduction It is widely recognized that, as polymer solution flows in a porous medium, a portion of the polymer is retained. It is evident that both physical adsorption and mechanical entrapment contribute to polymer retention. The question of the relative importance of these retention mechanisms has not been studied adequately. The effect of residual oil saturation on polymer retention and the polymer retention during the displacement of oil from porous media has also been studied inadequately. Mungen et al. have reported a few data on polymer concentration in produced water in oil-recovery tests. However, no produced water in oil-recovery tests. However, no comparison was made between polymer retention at 100-percent water saturation and at partial oil saturation. It has been shown that the actual size of the flowing polymer molecules, with the associated water, can approach the dimensions of certain smaller pores found in porous media. Therefore, an inaccessible pore volume exists in which no polymer flow occurs. In this study, the existence polymer flow occurs. In this study, the existence of inaccessible pore volume is shown clearly, both in sand and sandstone. Although polymer-retention values have been reported for various conditions, correlation is difficult because of the differing conditions of measurements. The effect of slug size, polymer concentration, salinity, and type of porous media on polymer retention has not been systematically studied. The purpose of this study was to develop answers to these questions, rather than to provide adsorption data for actual field core samples. For this reason, unconsolidated silica sands were used in most of the experiments reported. This permitted identical, uniform single-layer and multilayer porous media to be constructed for repeated experiments under varying test conditions. Some experiments were also carried out in Berea sandstone cores to determine whether sand-pack results can be extrapolated to consolidated sandstones. Using a C 14-tagged polymer provided a very rapid, simple, and accurate polymer-concentration determination technique. SPEJ P. 323

Effect of Concentration on HPAM Retention in Porous Media

SPE Journal ◽  
2014 ◽  
Vol 19 (03) ◽  
pp. 373-380 ◽  
Author(s):  
Guoyin Zhang ◽  
R.S.. S. Seright
Keyword(s):  
Porous Medium ◽  
Porous Media ◽  
Polymer Solution ◽  
Polymer Concentration ◽  
Retention Mechanism ◽  
Dynamic Measurements ◽  
Polymer Molecules ◽  
Adsorbed Polymer ◽  
Hydrolyzed Polyacrylamide ◽  
Polymer Retention

Summary This paper investigates the effect of hydrolyzed polyacrylamide (HPAM) polymer concentration on retention in porous media by use of both static and dynamic measurements. Consistent results by use of these two methods show that different polymer-retention behaviors exist in dilute, semidilute, and concentrated regions. In both the dilute and concentrated regions, polymer retention has little dependence on concentration. In contrast, in the semidilute region, polymer retention is concentration dependent. If a porous medium is first contacted sufficiently with dilute polymer solution to satisfy the retention, no significant additional retention occurs during exposure to higher HPAM concentrations. On the basis of the experimental results, a concentration-related retention mechanism is proposed that considers the orientation of the adsorbed polymer molecules and the interaction between molecular coils in solution. By use of this model, we explain why polymer retention does not show much dependence on concentration in the dilute and concentrated regimes. Further, in the semidilute region, we explain how moderate coil interactions lead to mixed adsorbed-polymer orientation and magnitude on rock surfaces, and retention becomes concentration dependent. In field applications of polymer and chemical floods, reduced polymer retention may be achieved by first injecting a low-concentration polymer bank.

scholarly journals Study on the Impact of Polymer Retention in Porous Media on Further Surfactant-Polymer Flood

2015 ◽  
Vol 8 (1) ◽  
pp. 45-50 ◽  
Author(s):  
Junjian Li ◽  
Hanqiao Jiang ◽  
Qun Yu ◽  
Fan Liu ◽  
Hongxia Liu
Keyword(s):  
Porous Media ◽  
Oil Recovery ◽  
Underground Water ◽  
Polymer Flooding ◽  
Polymer Flood ◽  
Good Potential ◽  
Enhance Oil Recovery ◽  
Polymer Application ◽  
The Impact ◽  
Polymer Retention

Polymer flood gains expansive popularity as a promising EOR method in various oilfields worldwide. However, there are still substantial amount of resources underground after polymer application. To further enhance oil recovery, secondary chemicals are sometimes utilized to sweep the remaining hydrocarbons to maintain the consistent development of oilfields. In this paper, a series of experiments are established and conducted to explore the feasibility of surfactant/ polymer flooding applied to a polymer flooded reservoir, and also the influence of polymer retention in porous media to enhance the oil recovery performance of subsequent chemical drive. The data of the experiments suggest that surfactant/polymer flooding owns a very good potential as a subsequent EOR technique, and that polymer retention in pores helps block underground water channels, improving greatly the sweeping efficiency of secondary chemical flood.

Mechanisms of polymer retention in porous media

2020 ◽  
pp. 126-134
Author(s):  
E.F. Veliyev ◽  
Keyword(s):  
Porous Medium ◽  
Porous Media ◽  
Enhanced Oil Recovery ◽  
Oil Recovery ◽  
Field Research ◽  
Polymer Flooding ◽  
Successful Implementation ◽  
Key Factors ◽  
Factors Affecting ◽  
Polymer Retention

Polymer flooding is one of the main enhanced oil recovery methods that have been actively used since the late 1960s. However, despite the significant gained experience of both laboratory and field research, this technology still continues to develop from year to year, revealing more and more new factors and challenges that are necessary aspects for successful implementation. Estimation of retained polymer amount by the porous medium is one of the key factors. The article discusses the main mechanisms and factors affecting retention process, as well as methods for determining the amount of retained polymer when flooding the solution through porous medium in laboratory conditions.

Retention and Flow Characteristics of Polymer Solutions in Porous Media

1977 ◽  
Vol 17 (02) ◽  
pp. 111-121 ◽  
Author(s):  
J.G. Dominguez ◽  
G.P. Willhite
Keyword(s):  
Porous Media ◽  
Flow Rate ◽  
Polymer Solutions ◽  
Polymer Concentration ◽  
Flow Characteristics ◽  
Porous Matrix ◽  
Polymer Molecules ◽  
Partially Hydrolyzed Polyacrylamide ◽  
Hydrolyzed Polyacrylamide ◽  
Polymer Retention

Abstract Retention and flow characteristics of a solution containing Pusher 700, a high-molecular-weight, partially hydrolyzed polyacrylamide, were studied partially hydrolyzed polyacrylamide, were studied in an 86-md core made by compacting Teflon powder. The quantity, of polymer retained during linear displacement experiments ranged from 10 to 21 mu gm/gm for polymer concentrations of 100 to 500 ppm in 2-percent NaCl solutions. Nearly all retention ppm in 2-percent NaCl solutions. Nearly all retention was attributed to mechanical entrapment because of low polymer adsorption on the Teflon surface. Flow rate affected polymer retention. In increase in velocity was accompanied by polymer retention. Polymer was expelled when the flow rate was Polymer was expelled when the flow rate was reduced. Inaccessible pore volume was about 19 percent of the total pore volume. percent of the total pore volume.Resistance factors in different sections of the core ranged Pam 2 to 10 /or solutions of 100 to 500 ppm polymer concentration in 2-percent NaCl. ppm polymer concentration in 2-percent NaCl. Permeability reduction resulting from polymer Permeability reduction resulting from polymer retention produces the resistance factor in most of the core at a velocity of 3.2 ft/D. Resistance factors in the Teflon cores were two to three times lower than those reported for natural porous media where polymer is also retained by adsorption. Introduction The search for a low-cost, effective mobility control agent is currently focused on dilute aqueous solutions containing partially hydrolyzed polyacrylamides or polysaccharides. Rheological polyacrylamides or polysaccharides. Rheological properties have been studied, including the properties have been studied, including the effects of polymer concentration, shear rate, electrolyte concentration, and type of electrolyte. Correlation of rheological data and models with the flow behavior of polymer solutions in porous media has been complicated by the many interactions that occur between the complex porous matrix and the polymer solutions. Some data have been correlated using non-Newtonian rheological models to describe the variation of fluid viscosity with the apparent shear rate that the fluid experiences as it flows through the tortuous paths in porous media. These correlations have adjustable parameters determined from the particular set of parameters determined from the particular set of data used to develop the correlation. Investigators studying partially hydrolyzed polyacrylamide solutions observed apparent polyacrylamide solutions observed apparent viscosities 5 to 20 times the values measured in a conventional viscometer at the shear rates believed to exist in the porous media. These viscosity increases were not anticipated from the rheological behavior of the fluids. Pye introduced the concept of the resistance factor to quantify this effect. Burcik observed a decrease in the mobility of brine in a Berea sandstone disk that had been previously contacted with partially hydrolyzed previously contacted with partially hydrolyzed polyacrylamide. The mobility reduction persisted polyacrylamide. The mobility reduction persisted even after 100 PV of brine had been flushed through the disk. Burcik concluded that polymer molecules retained in the pore structure by adsorption or mechanical entrapment were hydrophillic and restricted the flow of water. Gogarty made an extensive experimental study of partially hydrolyzed polyacrylamide solutions in porous media and concluded that these polymer porous media and concluded that these polymer solutions reduced the permeability of the porous media. He noosed that polymer retention in natural cores occurred by mechanical entrapment and adsorption. Both mechanisms contributed to the resistance and residual or flushed resistance factors observed with polyacrylamide solutions. Other evidence of interactions between the polymer solution and the porous matrix was found. polymer solution and the porous matrix was found. Adsorption of polymer molecules on the surface of materials present in the porous matrix has been demonstrated in batch adsorption experiments. Material-balance calculations made on the streams entering and leaving porous media following step changes in concentrations show retention of polymer molecules in the porous media. polymer molecules in the porous media. A dependence of polymer retention on flow rate has been reported. Szabo devised a set of static and flow experiments in which polymer adsorption was held to a low level by using silica sand with a small surface area. Mechanical entrapment was found to be the dominant retention mechanism in short sand packs. packs. SPEJ P. 111

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