Colloidal dispersion gels for in-depth permeability modification

2020 ◽  
pp. 2150038
Author(s):  
B. A. Suleimanov ◽  
E. F. Veliyev ◽  
N. V. Naghiyeva
Keyword(s):  
Sulfonic Acid ◽  
Polymer Concentration ◽  
Gelation Time ◽  
Colloidal Dispersion ◽  
Polymer Mixture ◽  
Residual Resistance ◽  
Hydrolyzed Polyacrylamide ◽  
Permeability Modification ◽  
Residual Resistance Factor

In this study, we describe the synthesis, characterization and evaluation of colloidal dispersion gels (CDGs) to be used as in-situ fluid diversion. The chemical stability of CDGs was improved by modifying the polymer mixture. The CDGs were synthesized by free radical crosslinking polymerization using 2-acrylamido-2-methylpropane sulfonic acid (AMPS), Acrylic acid (AAc), partially hydrolyzed polyacrylamide (HPAM) and chromium triacetate crosslinker. The effect of crosslinker/polymer concentration, salinity, gelation time, rheological behavior, particle size distribution of CDGs, also their thermo-chemical stabilities and resistance/residual resistance factor (RRF) were investigated.

Transport of Polymers in Low Permeability Carbonate Rocks

2021 ◽  
Author(s):  
Haofeng Song ◽  
Pinaki Ghosh ◽  
Kishore Mohanty
Keyword(s):  
Polymer Concentration ◽  
Material Balance ◽  
Economic Feasibility ◽  
Resistance Factor ◽  
Residual Oil ◽  
Residual Resistance ◽  
Oil Saturation ◽  
Residual Oil Saturation ◽  
Polymer Transport ◽  
Residual Resistance Factor

Abstract Polymer transport and retention affect oil recovery and economic feasibility of EOR processes. Most studies on polymer transport have focused on sandstones with permeabilities (k) higher than 200 mD. A limited number of studies were conducted in carbonates with k less than 100 mD and very few in the presence of residual oil. In this work, transport of four polymers with different molecular weights (MW) and functional groups are studied in Edwards Yellow outcrop cores (k<50 mD) with and without residual oil saturation (Sor). The retention of polymers was estimated by both the material balance method and the double-bank method. The polymer concentration was measured by both the total organic carbon (TOC) analyzer and the capillary tube rheology. Partially hydrolyzed acrylamide (HPAM) polymers exhibited high retention (> 150 μg/g), inaccessible pore volume (IPV) greater than 7%, and high residual resistance factor (>9). A sulfonated polyacrylamide (AN132), showed low retentions (< 20 μg/g) and low IPV. The residual resistance factor (RRF) of AN132 in the water-saturated rock was less than 2, indicating little blocking of pore throats in these tight rocks. The retention and RRF of the AN132 polymer increased in the presence of residual oil saturation due to partial blocking of the smaller pore throats available for polymer propagation in an oil-wet core.

scholarly journals Modeling of Chemical Water Shut off Treatments

2019 ◽  
Vol 2 (1) ◽  
Keyword(s):  
Polymer Concentration ◽  
High Water ◽  
Resistance Factor ◽  
Real Field ◽  
Water Production ◽  
Polymer Gel ◽  
Core Flooding ◽  
Great Chance ◽  
Residual Resistance ◽  
Residual Resistance Factor

Water production is one of the major problems that been encountered in the oil industry, which may cause corrosion of tubular, fine migration and acceleration of well abandonment. More than $40 billion is spent yearly dealing with unwanted water, so a treatment should be implemented to reduce high water production. Many papers investigated and focused their researches on how to reduce water cut percentage. Mechanical and chemical treatments are suggested, chemical treatment represented in polymer-gel with cross linker solution proved optimistic results. Gel can solve many types of water production problems rather than other chemical or other mechanical treatments. In this paper a model was constructed to determine the applicability of gels in reducing water permeability. The model included equations predicted using statistical software (SPSS) that determines the water residual resistance factor (Frrw) and the oil residual resistance factor (Frro) by inserting polymer concentration then determine the optimum concentration which gives the most desired results. A real field data was obtained from Z field (well X, well Y, and Well Z) and gel applicability in permeability reduction had been tested, then an optimistic result obtained. The outcomes of this study investigate that there is a great chance to apply polymer-gel as water shut-off technique. For future work a full core-flooding study must be constructed to obtain more set of data and improvement of the equations accuracy

scholarly journals Effect of Polymer Adsorption on Permeability Reduction in Enhanced Oil Recovery

2014 ◽  
Vol 2014 ◽  
pp. 1-9 ◽  
Author(s):  
Saurabh Mishra ◽  
Achinta Bera ◽  
Ajay Mandal
Keyword(s):  
Oil Recovery ◽  
Polymer Concentration ◽  
Polymer Adsorption ◽  
Mobility Control ◽  
Special Focus ◽  
Permeability Reduction ◽  
Solution Ph ◽  
Residual Resistance ◽  
Polymer Injection ◽  
Hydrolyzed Polyacrylamide

In order to reduce the permeability to water or brine, there is a possibility of polymer injection into the reservoir. In the present work, special focus has been paid in polymer [partially hydrolyzed polyacrylamide (PHPA)] injection as a part of chemical method. Tests were conducted in the laboratory at the ambient temperature to examine the reduction in permeability to water or brine in the well-prepared sand packed after the polymer injection. The experiments were performed to study the effect of polymer adsorption on permeability reduction by analyzing residual resistance factor values with different concentrations of polymer solutions. The rheological behavior of the polymer has also been examined. The experimental results also indicate that the adsorption behavior of polymer is strongly affected by salinity, solution pH, and polymer concentration. To investigate the effect of polymer adsorption and mobility control on additional oil recovery, polymer flooding experiments were conducted with different polymer concentrations. It has been obtained that with the increase in polymer concentrations, oil recovery increases.

Rheological Monitoring of the Formation of Polyacrylamide/Cr+3 Gels

1983 ◽  
Vol 23 (05) ◽  
pp. 804-808 ◽  
Author(s):  
Robert K. Prud'homme ◽  
Jonathan T. Uhl ◽  
John P. Poinsatte
Keyword(s):  
Metal Ions ◽  
Storage Modulus ◽  
Shear Viscosity ◽  
Polymer Concentration ◽  
Gelation Time ◽  
Three Dimensional ◽  
Reducing Agent ◽  
Chromium Ion ◽  
Kinetics Of

Abstract The formation of polyacrylamide/chromium-ion gels has been followed rheologically. The time dependence of the storage modulus has been used to analyze the kinetics of the gelation process. The kinetic theory of rubber elasticity has been used to determine the crosslink density in the gel from the measured value of the storage modulus. The effects of changing polymer, chromium ion, and reducing agent concentrations have been studied. polymer, chromium ion, and reducing agent concentrations have been studied. Introduction Water-soluble polymers of high molecular weight, such as polyacrylamides, polysaccharides, and hydroxyl ethyl celluloses, have been studied as polysaccharides, and hydroxyl ethyl celluloses, have been studied as water flooding additives since the late 1950's. These polymers are added to control fluid movement in reservoirs to improve sweep efficiencies. In addition to enhanced fluid mobility control in porous media by increased viscosities of polymer solutions, the injection of dilute (250 ppm) polyacrylamide solutions causes permeability reductions that persist after polyacrylamide solutions causes permeability reductions that persist after the mobile polymer is flushed from the pore space by water. This reduction in permeability to water is a result of the retention of polyacrylamide in the porous rock by adsorption and mechanical entrapment. Rock permeability also can be reduced deliberately by crosslinking a polyacrylamide solution in situ to form a three-dimensional (3D) gel. The polyacrylamide solution in situ to form a three-dimensional (3D) gel. The gelled polymer is capable of shutting off fractures and zones of high permeability. The rate at which this 3D gel is formed determines how far permeability. The rate at which this 3D gel is formed determines how far the solution can be pushed into the rock formation away from the injection well before gelation occurs. Polyacrylamides are known to form gels in the presence of Cr+3 ions. The process involves the reduction of Cr+6 to Cr+3 with a reducing agent such as sodium bisulfite or thiourea. When Cr+6 is reduced to Cr+3, the trivalent chromium ion and polymer react slowly to form a 3D gel structure. The mechanism by which polyacrylamide or partially hydrolyzed polyacrylamide forms gels in the presence of metal ions is not well polyacrylamide forms gels in the presence of metal ions is not well understood. One idea is that Cr+3 serves as a crosslinking agent between the polyacrylamide molecules. Another suggestion is that Cr+3 forms a stable dispersion in the polymer solution, resulting in either a highly viscous liquid or a gel. Only a limited amount of data has been published on the kinetics of the polyacrylamide/chromium ion gelation process. Terry et al. followed the increase of the steady shear viscosity with time after the introduction of a reducing agent to a polyacrylamide/Cr+6 solution. Gelation time was defined as the time required for the shear viscosity to reach an arbitrary value. The effects of varying polymer type and concentration, Cr+6 concentration, and reducing agent type and concentration were investigated. A linear relationship was found between the reciprocal of the gelation time and the reciprocal of the polymer concentration for a given polymer reducing agent system. The gelation time decreases both with increasing polymer concentration and with increasing Cr+6 and reducing agent polymer concentration and with increasing Cr+6 and reducing agent concentrations. An Arrhenius-type relationship was shown between gelation time and temperature by Willhite and Jordan. During the buildup of a 3D gel network, the shear viscosity increases, but the shearing motion imposed on the sample also tends to break down the network being formed. SPEJ p. 804

scholarly journals SENSITIVITY ANALYSIS FOR POLYMER INJECTION TO IMPROVE HEAVY OIL RECOVERY – SMALL-SCALE SIMULATION STUDY

2021 ◽  
Vol 14 (04) ◽  
pp. 239-258
Author(s):  
M. F. Zampieri ◽  
C. C. Quispe ◽  
R. B. Z. L. Moreno
Keyword(s):  
Oil Recovery ◽  
Heavy Oil ◽  
Pore Volume ◽  
Polymer Concentration ◽  
Polymer Flooding ◽  
Small Scale ◽  
Average Pressure ◽  
Residual Resistance ◽  
Water Viscosity ◽  
Residual Resistance Factor

Polymer flooding has been widely used for enhancing oil recovery, due to the growing number of successful applications around the world. The process aims to increase water viscosity and, thus, decrease the water/oil mobility ratio, thereby improving sweep efficiency. The understanding of the physical mechanisms involved in this enhanced oil recovery process allows us to forecast the application potential of polymer flooding. This work aims to assess physical phenomena associated with heavy oil recovery through polymer flooding using 1D small-scale simulation models. We evaluate the influence of different levels of adsorption, accessible pore volume, residual resistance factor, and polymer concentration on the results and compare their magnitude effect on the results. The models used in this study were built using data from previous lab work and literature. For each one of the mentioned parameters, this work compares the histories of water cut, cumulative water-oil ratio, average pressure, and oil recovery factor. Additionally, water saturation, water viscosity, and water mobility profile were determined for specific periods of the flooding process. The sensitivity analyses showed that high levels of adsorption influence the polymer loss of the advance front, delaying oil recovery. Low values of accessible pore volume lead to a slightly faster polymer breakthrough and oil recovery anticipation. A high residual resistance factor increases the average pressure and improves oil recovery. Higher polymer concentration enhances the displacement efficiency and enhances the recovery factor.

Correlation of Gelation Times for Polymer Solutions Used as Sweep Improvement Agents

1981 ◽  
Vol 21 (02) ◽  
pp. 229-235 ◽  
Author(s):  
Ronald E. Terry ◽  
Chyi-gang Huang ◽  
Don W. Green ◽  
Michael J. Michnick ◽  
G. Paul Willhite
Keyword(s):  
Oil Recovery ◽  
Metal Ion ◽  
Water Movement ◽  
Polymer Concentration ◽  
Gelation Time ◽  
Reducing Agent ◽  
Ion Concentration ◽  
Fluid Movement ◽  
Polymer Hydrolysis

Abstract Gelled polymers are being used increasingly to redirect or modify reservoir fluid movement in the vicinity of injection or production wells for the purpose of improving water/oil ratios. To date, little has been reported about the chemistry of the in-situ gelling process that involves a multivalent metal ion, a reducing agent, and a polymer. This paper reports results of a study of the relationship between process parameters and gelation time, which is defined as the time required for the solution to reach a specified viscosity. The gelation time is determined by continuous monitoring of the viscosity following addition of the chemical reactants. The varied parameters in the investigation include polymer type and concentration, chromate concentration, and reducing-agent type and concentration. Five different polyacrylamide polymers were used including polyacrylamides that were hydrolyzed to different degrees, an anionic copolymer, and a cationic copolymer. Sodium bisulfite and thiourea were used as reducing agents. It was determined that for a given polymer-reducing agent system, the reciprocal of gelation time is a linear function of the reciprocal of the polymer concentration for a fixed metal ion concentration. The slope of the straight line is a function of the degree of polymer hydrolysis, the existence of the anion or cation functional groups, and type of reducing agent used. Introduction Waterflooding generally has proved to be a highly successful oil recovery process. In those reservoirs where waterflooding has not been successful, the primary causes have been low sweep efficiencies and the bypassing of oil by water due to viscous fingering. Low sweep efficiencies can be caused by water channeling through fractures or zones of high permeability.The production of a large amount of water relative to the amount of oil produced is often a result of poor sweep efficiency in a waterflood project. Large water/oil ratios (WOR) and the subsequent handling and treating of the produced water lead to high operating costs and often make it uneconomical to continue a waterflooding program.Even where waterflooding has been successful, large volumes of water usually have been required. The economics have been justified by the fact that water is inexpensive and can be recirculated. Since water is relatively inexpensive to inject, there usually has been little concern about controlling the water movement in the reservoir while WOR remained below some predetermined (by economics) value.However, with the implementation of tertiary recovery methods, some of which involve the addition of expensive chemicals to the floodwater, it becomes very important that good fluid control be established. This is necessary so that the maximum volume of the reservoir is contacted by a minimum amount of fluid.There have been many attempts to control fluid movement in reservoirs to improve sweep efficiencies. Methods that have been among the most successful have used polymers, usually polyacrylamides, in some form. Polyacrylamides are thought to be especially effective since they have the ability to reduce formation permeabilities to water while retaining the permeabilities to oil. Early treatment involved simply the injection of polymers. Recent developments have shown that polyacrylamides can be crosslinked in situ to form a three-dimensional gel. SPEJ P. 229^

Electron Microscopy of Mycoplasma Pneumoniae

1971 ◽  
Vol 29 ◽  
pp. 258-259 ◽  
Author(s):  
E. S. Boatman ◽  
G. E. Kenny
Keyword(s):  
Electron Microscopy ◽  
Light Microscopy ◽  
Growth Phase ◽  
Hela Cells ◽  
Sulfonic Acid ◽  
Gamma Globulin ◽  
Horse Serum ◽  
Morphological Aspects ◽  
The Family

Information concerning the morphology and replication of organism of the family Mycoplasmataceae remains, despite over 70 years of study, highly controversial. Due to their small size observations by light microscopy have not been rewarding. Furthermore, not only are these organisms extremely pleomorphic but their morphology also changes according to growth phase. This study deals with the morphological aspects of M. pneumoniae strain 3546 in relation to growth, interaction with HeLa cells and possible mechanisms of replication.The organisms were grown aerobically at 37°C in a soy peptone yeast dialysate medium supplemented with 12% gamma-globulin free horse serum. The medium was buffered at pH 7.3 with TES [N-tris (hyroxymethyl) methyl-2-aminoethane sulfonic acid] at 10mM concentration. The inoculum, an actively growing culture, was filtered through a 0.5 μm polycarbonate “nuclepore” filter to prevent transfer of all but the smallest aggregates. Growth was assessed at specific periods by colony counts and 800 ml samples of organisms were fixed in situ with 2.5% glutaraldehyde for 3 hrs. at 4°C. Washed cells for sectioning were post-fixed in 0.8% OSO4 in veronal-acetate buffer pH 6.1 for 1 hr. at 21°C. HeLa cells were infected with a filtered inoculum of M. pneumoniae and incubated for 9 days in Leighton tubes with coverslips. The cells were then removed and processed for electron microscopy.

Design of Ionic Liquid 3-Methyl-1-sulfonic Acid Imidazolium Nitrate as Reagent for the Nitration of Aromatic Compounds by in Situ Generation of NO2 in Acidic Media

2012 ◽  
Vol 77 (7) ◽  
pp. 3640-3645 ◽  
Author(s):  
Mohammad A. Zolfigol ◽  
Ardeshir Khazaei ◽  
Ahmad R. Moosavi-Zare ◽  
Abdolkarim Zare ◽  
Hendrik G. Kruger ◽  
...  
Keyword(s):  
Ionic Liquid ◽  
Aromatic Compounds ◽  
Sulfonic Acid ◽  
Acidic Media ◽  
In Situ Generation

scholarly journals DEVELOPMENT AND CHARACTERIZATION OF IN SITU GEL OF XANTHAN GUM FOR OPHTHALMIC FORMULATION CONTAINING BRIMONIDINE TARTRATE

2018 ◽  
Vol 11 (7) ◽  
pp. 277 ◽  
Author(s):  
Vazir Ashfaq Ahmed ◽  
Divakar Goli
Keyword(s):  
Drug Release ◽  
Xanthan Gum ◽  
Gelation Time ◽  
Gel Strength ◽  
Eye Drops ◽  
In Situ Gel ◽  
23 Factorial Design ◽  
Brimonidine Tartrate

Objective: The goal of this study was to develop and characterize an ion-activated in situ gel-forming brimonidine tartrate, solution eye drops containing xanthan gum as a mucoadhesive polymer.Method: Sol-gel formulation was prepared using gellan gum as an ion-activated gel-forming polymer, xanthan gum as mucoadhesive agent, and hydroxypropyl methyl cellulose (HPMC E50LV) as release retardant polymer. Phenylethyl alcohol is used as preservatives in borate buffer. The 23 factorial design was employed to optimize the formulation considering the concentration of gelrite, xanthan gum and HPMC as independent variables, gelation time, gel strength, and mucoadhesive force (N). Gelation time , gel strength, mucoadhesive force (N), viscosity (cP) and in vitro percentage drug release were chosen as dependent variables. The formulation was characteristics for pH, clarity, isotonicity, sterility, rheological behavior, and in vitro drug release, ocular irritation, and ocular visualization.Result: Based on desirability index of responses, the formulation containing a concentration of gelrite (0.4%), xanthan gum (0.21%), and HPMC (HPMC E50 (0.24%) was found to be the optimized formulation concentration developed by 23 factorial design. The solution eye drops resulted in an in situ phase change to gel-state when mixed with simulated tear fluid. The gel formation was also confirmed by viscoelastic measurements. Drug release from the gel followed non-fickian mechanism with 88% of drug released in 10 h, thus increased the residence time of the drug.Conclusion: An in situ gelling system is a valuable alternative to the conventional system with added benefits of sustained drug release which may ultimately result in improved patient compliance.

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