Preformed Particle Gel Research Articles

Rheological properties and the micromodel investigation of nanosilica gel-reinforced preformed particle gels developed for improved oil recovery

Preformed particle gels (PPGs) in solutions have been widely used to suppress excess water production in mature oil reservoirs and, in turn, to improve the amount of oil recovery in brown oil fields. In this study, PPG solutions were meticulously formulated and synthesized in order to be utilized in harsh environments in terms of pressure, temperature, pH, and salinity from a free radical polymerization process.In this work, nanosilica gel at different weight percentages was added to improve the mechanical and thermal stability properties of the PPG at harsh condition: high pressure, temperature, and strain. Moreover, the effects of nanosilica gel at various concentrations, ranging from 0.0 to 1.0 wt%, on the PPG swelling properties in a 100,000 ppm brine along with the viscoelastic behavior of acrylamide copolymer (AM) and 2-acrylamido-2-methyl-1-propane sulfonic acid (AMPS) with crosslinker of polyethylenimine (PEI) at 90 °C were studied. Having customized the formulation of the nanosilica-reinforced PPG, the solution was used to investigate the amount oil recovered in a water flooding process on a micromodel scale.The results for the recovery of oil obtained from the injection of PPG solutions were compared with those of water injection without PPG; i.e., the conventional water flooding. It should be stated that the microscopic images showed that nanosilica gel could affect the porous structure of the PPG and the X-ray Powder Diffraction (XRD) results confirmed the nanosilica particle distribution in the PPG pores with different diameters. Hence, the nanosilica-reinforced AM-AMPS/PEI with 1 wt% of the nanoparticles led in swelling of 8 g/g of the dried PPG. In addition, the strain sweep test at 90 °C suggest that increasing of nanosilica gel concentration from 0.2 to 1.0 wt% resulted in 3.34 times increase in the amount of elastic resistance of the PPG breakpoint and, thus, improvement in the complex modulus of initial PPG.In conclusion, the injection of PPG solutions, significant improvement in the oil recovery could be attained. The oil recovery factor increased from 32% under the conventional water flooding to 81% after injection of water with PPG containing only 1 wt% of nanosilica gel. Succinctly, the results confirmed that the tailored formulation had a great potential for field applications to enhance the oil recovery.

A comparative study of the mechanism and performance of surfactant- and alkali-polymer flooding in heavy-oil recovery

The performances of surfactant-polymer (SP) and alkali-polymer (AP) systems in recovering heavy oil were systematically compared via interfacial tension (IFT), emulsification, and oil displacement experiments. Significant differences of heavy-oil-recovery mechanism by SPs and APs are firstly revealed, those are, ultra-low IFT and oil-in-water (O/W) emulsification dominate using the former, while water-in-oil (W/O) emulsification dominates using the latter. Further more, AP (and its corresponding mechanisms) significantly outperform the SP in terms of heavy-oil recovery. Fortunately, the SPs can be improved by increasing the slug size, using preformed particle gels or bubble assistance, among which bubble-assisted ultra-low-IFT SP (foam) behaved the best. The success of AP and foam suggests two feasible routes for improving heavy-oil recovery: (i) forming W/O emulsions using alkali-containing systems; and (ii) improving ultra-low-IFT systems using profile-control agents, e.g. bubble. If the problem of scaling using alkali is considered, then the second idea may be the best option.

Static and dynamic evaluation of the effect of nanomaterials on the performance of a novel synthesized PPG for water shut-off and improved oil recovery in fractured reservoirs

Among different methods which are introduced to reduce unwanted water production, “Preformed Particle Gel” (PPG) is a recently developed type of these gels that can have important advantages such as temperature resistance and long-term stability. The aim of the present work is to synthesize a new type of PPG in which the above specifications are improved even further with the advantage of the Nano-material (here after called N-PPG) and then investigate its effectiveness via static bulk tests as well as dynamic Hele-Shaw and Micromodel tests. In static tube tests, the swelling performance of N-PPG samples was evaluated under different conditions. The examined parameters include various pH of the environment, the type and concentration of ions in the brine, temperature, particle size, and presence of carbon dioxide. Static results proved the temperature stability, pH-insensitivity, and long-term stability of the synthesized N-PPG. The PPG with the most suitable specification in the bulk tests was selected for further performance analysis in dynamic tests through Hele-Shaw cell and micromodel setups. The effectiveness and performance of the N-PPG on increasing the sweep efficiency of water injection and improving the oil production in Low Salinity Water flooding (LSWF) was studied for fractured systems. Dynamic Hele-Shaw cell tests showed that residual resistance factor (the factor which defines the gel ability to control water fingering) decreased with the increment of the brine concentration and the injection rate above a certain limit. In addition the size of dry particles shall be optimized for the best outcome of the treatment. The experimental results in the presence of CO2 showed superior sealing and dehydration performance of the present N-PPG compared to the PPG samples reported in the open literature. Eventually, visual micromodel tests revealed the involved microscale displacement mechanisms and confirmed the effectiveness of the swollen gel particles for reducing the effective permeability of the wide fractures and diverting the flow of the water to the matrix and as a result improving the sweep efficiency without intruding to the matrix and causing any formation damage or skin.

A comprehensive review of hydrogel performance under CO2 conditions for conformance control

Hydrogels with different compositions have been designed to improve CO2 sweep efficiency and to reduce excessive CO2 production by reducing reservoir heterogeneity. The hydrogels that have been applied in CO2 flooding can be classified into three major types: in-situ gel, foamed gel, and preformed particle gel. The polymerization of monomer gel happens in the reservoirs; however, the monomer gels were replaced by cost-effective polymer gels due to economic and environmental concerns. Conventional polymer gels include metallically crosslinked PAM gel, organically crosslinked PAM gel and biopolymer gel. The most commonly used polymer gel in the CO2 flooding fields is the HPAM/Cr(III) polymer gel. A variety of hydrogels were applied in the CO2 flooding fields; however, the field application results are mixed. In order to improve the hydrogel performance under the CO2 condition, some novel gels were developed in the laboratories. The primary purpose of this study is to review hydrogel performance under the CO2 condition and provide recommendations for future gel development for CO2 flooding.

Preformed particle gels of sulfonated polyacrylamide: preparation, characterization, and application as permeability modifier

In this study, a preformed particle gel (PPG) was synthesized from sulfonated polyacrylamide and chromium metal cross-linker with specific concentration. The main characteristics of PPG, such as gelation time, gel fraction, swelling properties and salt sensitivity factor were investigated. The gel fraction of 94.1% practically indicated an appropriate conversion of gelant to the gel. The equilibrium swelling ratios of particle gels in distilled water and formation water at 80 °C were 470.49 and 12.61, respectively. Additionally, the rheological properties of gel were studied by a dynamic rheometer. The ultimate storage modulus of gel was measured 35.4 kPa. The linear viscoelastic behavior was observed at strain between 1 and 82.6% and gel structure was stable up to strain of 1120% with small reduction of storage modulus. The kinetics of gelation were also studied at different temperatures and tested against Avrami equation to determine the kinetic parameters. The Avrami exponents for two kinetic steps were about 2.29 and 0.80, respectively, indicating the rapid formation of the gel network at first step due to nucleation and two-dimensional growths of gel nuclei. Furthermore, a core flooding experiment was conducted to study PPG performance in porous media. The residual resistance factor of water and oil was 41.58 and 12.91, respectively. A value of 3.22 for the ratio of these two factors indicated the ability of the synthesized PPG to decrease water-effective permeability compared to oil-effective permeability in porous media.

Preformed particle gels with potential applicability for conformance control of oil reservoirs

ABSTRACTPreformed particle gel (PPG) is a particled superabsorbent crosslinking polymer that has been successfully applied to control conformance. The aim of this study was to develop and evaluate the properties of PPGs based on crosslinked partially hydrolyzed polyacrylamide with polyethyleneimine (PEI). The study was conducted into two steps: (1) the preparation of standard hydrogels, which were dried and grounded to obtain preformed particles, using the Sydansk strength code and rheology for evaluation and (2) the determination of the swelling degree from the PPGs under typical reservoir conditions (temperature of 90 °C and salinity int about 29,940 mg/L of total dissolved solids). Sydansk coding is a method that provides semiquantitative measures, and it is expressed in an alphabetic code from A to J. The results showed that the systems in ideal predetermined conditions (20,000 mg/L of HPAM, 4,500 mg/L of PEI, and crosslinking temperature of at 70 °C) allowed obtaining PPGs with Sydansk codes of F or H (highly deformable or slightly deformable nonfluid gel, respectively). According to the rheology tests, the systems had pseudoplastic behavior with characteristics of strong gels (G″/G′ < 0.1). Besides this, the swelling degree under reservoir conditions was independent of gel‐strength F or H that in both cases is around 19%, but increases with increasing temperature. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2020, 137, 48554.

Combining Preformed Particle Gel and Curable Resin-Coated Particles To Control Water Production from High-Temperature and High-Salinity Fractured Producers

SummaryPreformed-particle-gel (PPG) treatments have been successfully used in injection wells to reduce excessive water production from high-temperature, high-salinity fractured reservoirs. However, PPG itself cannot be used in fractured producers because it tends to wash out after the wells resume production. Therefore, we proposed to combine curable resin-coated particles (CRPs) with PPG to control water production from fractured producers. In this paper, millimeter-sized tubes and fractured carbonate cores were designed to comprehensively investigate water-plugging behaviors of the combined system under the conditions of various fracture parameters and PPG/CRP sizes. Particular attention was given to control the PPG washout after production was resumed. The results showed the cured CRPs could generate immobile packs in fractures and dramatically mitigate the PPG washout. The small size of the CRPs and the small ratio of CRP size to tube diameter contributed low permeability and homogeneity to CRP packs. Meanwhile, the less-permeable and more-homogeneous CRP pack, as well as the larger-sized PPGs, contributed to a higher PPG breakthrough pressure gradient. Moreover, some of the PPG particles blocked in the CRP packs could be released through high-speed brine injection from producers, which indicated the recoverability of the water plugging. This study provides a promising approach to reduce the high-water-cut problem in fractured producers.

Experimental research on novel oil displacement and profile control system for heterogeneous reservoir

Polymer flooding and surfactant/polymer flooding (SP flooding) were mainly focused on the improvement in oil–water flow ratio and the reduction in oil–water interfacial tension. Preformed particle gel (PPG) flooding was mainly focused on the reservoir heterogeneity improvement. Each of these technologies has its own limitations. Heterogeneous system flooding (HS–PP flooding) was proposed as a novel flooding method aimed to improve oil–water flow ratio and reservoir heterogeneity at the same time. The HS–PP flooding system was composed of PPG and polymer solution. HS–PP flooding, polymer flooding and SP flooding as different chemical EOR methods were studied in laboratory in physical simulation heterogeneous model. Property of cubic expansion of PPG was researched by laser particle analyzer. The result shows that cubic expansion of PPG in simulation water is obvious and can be controlled. The effect of PPG on the diversion rate modification in double parallel sandstone model was obvious. The oil displacement experiments of the three different flooding systems with the same viscosity in physical simulation heterogeneous model were studied. The results show that the HS–PP flooding improves the oil recovery by 20.04%, comparing the result of 12.67% for polymer flooding and 16.66% for SP flooding, respectively. HS–PP flooding as a novel flooding method shows an excellent ability for stabilizing oil production and controlling water cut. The mechanism of the HS–PP flooding was discussed briefly. In addition to the viscoelastic displacement of polymers, the special circulation ability of “accumulating–deforming (collapsing)–accumulating again” of PPG is the main reason why the HS–PP flooding shows an excellent property for stabilizing oil production and controlling water cut.

An Investigation of CO2-Responsive Preformed Particle Gel for Conformance Control of CO2 Flooding in Reservoirs With Fractures or Fracture-Like Channels

Summary Gel treatment is an important technique to solve early CO2 breakthrough and excess–CO2–production problems, caused by the low viscosity and low density of CO2, as well as the heterogeneity of reservoirs with fractures or fracture–like channels. However, there is no reported work on gel that increases its volume after reacting with CO2 (termed CO2–responsive gel) for the conformance control of CO2 flooding. In this paper, the intrinsic properties of a CO2–responsive preformed particle gel (CR–PPG) were evaluated in a water/supercritical–CO2 (scCO2) environment in high–pressure vessels. Continuous scCO2 injection and CR–PPG treatment were conducted in fractured sandstone cores, to probe their plugging performance to scCO2 flow in a high–permeability–contrast system. The volumetric swelling ratio (VSR) of the CR–PPG increased by approximately two times in the presence of scCO2, compared with a sample under similar conditions in the absence of scCO2. The CR–PPG swelling ratio decreased with increasing NaCl concentration. Under the same conditions, the temperature did not have an apparent effect on the swelling ratio after 31 days of swelling. In coreflooding experiments, the placed CR–PPG resisted a considerable pressure up to 617.0 psi before breakthrough. After a shut–in process, CO2–breakthrough pressure was detected at 437.2 psi. It is observed that the shut–in process improved the plugging performance of CR–PPG to CO2 as revealed by the increase in the residual resistance factor. Controlling the shut–in time was found to be effective in augmenting the increase in the residual resistance factor, by increasing the VSR of placed CR–PPG. Resistance of CR–PPG to some real field challenges, including a high pressure gradient and long–term exposure to CO2, was also reported for field–applicability concerns.

Study on the flow resistance of the dispersion system of deformable preformed particle gel in porous media using LBM-DEM-IMB method

After being injected into the porous media, the dispersion system of preformed particle gel (PPG) tends to enter high permeability regions and block water channeling passages, which forces the subsequent water to turn to the low permeability regions and thus increases sweep efficiency and enhances oil recovery. However, it is still unclear about the influence factors and the mechanisms how PPG increases water flow resistance, which limits the application of PPG in more oilfields. Therefore, the paper combines the lattice Boltzmann method (LBM), the discrete element method (DEM) and the improved immersed moving boundary (IMB) method to simulate the migration of deformable PPG in porous media. On the basis, the paper quantitatively analyzes the variation law of displacement pressure across the porous media and discusses the influence factors such as the PPG diameter, elasticity modulus and the number concentration. Results indicate that, because of the friction and retention of PPG in pore-throat, the displacement pressure across the porous media during PPG flooding is much higher than that during water flooding. In other words, the existence of PPG increases the flow resistance of injected water. Besides, the displacement pressure is always fluctuant resulting from the continuous process of PPG migration, retention, deformation and remigration. Influence factor analysis shows that the incremental value and fluctuation degree of flow resistance increase with the PPG diameter, elasticity modulus and the number concentration. The study not only provides useful reference for future PPG flooding, but also benefits the development of deformable particle flow theory.

Shear resistance performance of low elastic polymer microspheres used for conformance control treatment

Low elastic polymer microsphere (L-EPM) has been proposed as a functional polymer microsphere these years. L-EMP has the excellent deformation ability in the porous medium due to the low storage modulus. Herein, one kind of L-EPM with storage modulus (G′) of 23.6 Pa was prepared by inverse suspension polymerization. The shear resistance of L-EPM was researched by using core flooding experiment and high shear rate emulsifier. The conformance control behavior of L-EPM was investigated by using double parallel sandpack flooding experiment. The results showed that L-EPM was a kind of swollen particle gel with three-dimensional net structure and contained amide, carboxyl, and sulfonate groups. The mechanism of water swelling property was mainly due to the formation of hydrogen bonds, hydrolysis of hydrophilic groups and the diffusion caused by osmotic pressure difference. Compared with high elastic polymer microspheres (H-EPM) and low elastic preformed particle gel (L-PPG), L-EPM had better shear resistance in the porous medium and the well casing perforation. In addition, the critical shear points of L-EPM was proposed in this work. Due to the better shear resistance and deformation ability, the conformance control behavior of L-EPM showed that L-EPM was a promising conformance control agent in the heterogeneous reservoirs.

The effect of stepwise increasing of water injection rates on enhanced oil recovery after preformed particle gel treatment

In the past ten years, preformed particle gel (PPG) has been widely applied in oil fields as an effective conformance control agent for reducing water cut in oilfield. However, there is little research on the injection rate of subsequent water flooding after PPG injection on recovery. In this paper, the swelling, scanning electron microscope, rheological and viscoelasticity tests were performed to investigate into the characteristics of PPG and explore the mechanism of enhancing oil recovery by stepwise increasing subsequent water injection rate. In the homogeneous and heterogeneous cores, the plugging effect of PPG was judged according to different pressures, and the subsequent water injection rate is 0.5–0.75, 1, 1.25, and 1.5 mL/min after the water cut of each injection rate reaches 100% stage. The distribution of residual oil in different displacement stages was studied by nuclear magnetic resonance (NMR). The experimental results show that the PPG has high viscoelasticity and can be fully swelled within 42 h in 70 °C. The subsequent increase in flow rate can promote the previous phase of the PPG particles remaining in the pore throat to move, and then have a better effect to drive the oil droplets attached to the rock surface. Stepwise increasing the subsequent water flooding injection rate in the homogeneous formation can improve the oil washing efficiency and reduce the residual oil saturation. In the heterogeneous formation, the recovery factor is improved by stepwise increasing the sweep coefficient.

A Recrosslinkable Preformed Particle Gel for Conformance Control in Heterogeneous Reservoirs Containing Linear-Flow Features

Summary Preformed particle gels (PPGs) have been successfully applied to control conformance for mature oil fields because of their advantages over conventional in-situ gels. However, field applications have demonstrated that current particle gels cannot efficiently plug open fractures, fracture-like channels, or conduits that exist in many mature oil fields. The objective of this study is to systematically evaluate a new recrosslinkable-PPG (RPPG) product that can be used to efficiently control the conformance for abnormal features. The RPPG can swell to 38 times its initial volume, and the equilibrium swelling ratio is independent of the brine salinity. Temperature and the particle size showed a gradient effect on the swelling rate of the gel. Additionally, the particle gels can recrosslink to form a rubber-like bulky material in the large-opening features after placement that significantly enhances the plugging efficiency. We systematically evaluated the effect of temperature and RPPG swelling ratio on the recrosslinking time, the gel strength after crosslinking, and the gel thermostability. Coreflooding tests were run to test whether RPPG can significantly improve the fracture-plugging efficiency compared with a traditional PPG that cannot recrosslink after pumping. The RPPG can be customized for mature reservoirs with a temperature from 23 to 80°C with a controllable size from tens of nanometers to a few millimeters. The recrosslinking time can be controlled from 2 to 80 hours, depending on the swelling ratio and temperature. The gel elastic modulus after recrosslinking can achieve from 300 to 10 800 Pa, depending on the swelling ratio and the temperature. Coreflooding tests showed that the breakthrough pressure of the recrosslinked RPPG can reach up to 300 psi/ft for a fracture with a 0.2-cm aperture, which is more than five times higher than that of the conventional PPG.

Experimental Evaluation of Oxidizing Breakers for a Polyacrylamide-Based Re-Crosslinkable Preformed Particle Gel

Re-crosslinkable preformed particle gel (RPPG) is a newly developed conformance control agent that can reassemble as an integrity after swelling in water. However, the RPPG has the potential to plug the injection facilities or wellbore if a treatment is not properly designed. This study focuses on selecting and evaluating the oxidizing breakers that can effectively degrade the RPPG. Bottle tests were conducted by immersing the re-crosslinked RPPG in the breaker solutions. The RPPG weight change was measured with time to analyze the breaking process. Four types of oxidizing breakers, NaClO, Ca(ClO)2, heat-activated Na2S2O8, and NaOH-activated Na2S2O8 were examined. The effect of factors, including breaker concentration, temperature, RPPG concentration on the gel breaking rate and completeness, was investigated. According to the results, three of the breakers were proven effective, excluding the Ca(ClO)2, which impaired the breaking process by generating a compact cover on the surface of RPPG. The NaOH-acti...

Investigation and Characterization of a Robust Nanocomposite Preformed Particle Gel for Enhanced Oil Recovery

A robust starch-grafted nanocomposite preformed particle gel (SN-PPG) with superior viscoelasticity and thermal stability is developed to improve the oil recovery. The effects of a cross-linker, an...

Effect of multiple factors on preformed particle gel placement, dehydration, and plugging performance in partially open fractures

Preformed particle gels (PPGs) have been successfully applied for solving conformance problems caused by fractures. In real reservoirs, a considerable portion of fractures have relatively short length and closed ends. However, PPG treatment in this typical kind of fractures, termed partially open fractures (POFs), was barely investigated in existing studies. Cylindrical sandstone cores were used to construct partially open fracture models. PPG placement and water floodings were conducted in the POF models to explore the effect of fracture length, fracture height, matrix permeability, and residual oil on the PPG placement, dehydration, and water-plugging performance. Up to 18 fracture volume (FV) of PPG could be placed under a 1000 psi placing pressure. With the same placing pressure, less FV of PPG was placed with the increase of fracture height, decrease of matrix permeability, or presence of residual oil, respectively. However, placement FV didn’t show an apparent change with the fracture length modification. The re-swelling experiments showed that PPG samples dehydrated when exposed to a high pressure difference between fracture and porous rock. The dehydration level of placed PPG yielded a positive correlation with the placement FV in all conducted experiments. The placed PPG blocked the water flow until a breakthrough pressure was reached. It performed a resistance to the water flow after breakthrough. The residual resistance factor increased when the fracture had a greater length, the matrix had a higher permeability, or residual oil absented in the core. The residual resistance factor was relatively independent of the partially open fracture height.

Study of the mechanisms of streamline-adjustment-assisted heterogeneous combination flooding for enhanced oil recovery for post-polymer-flooded reservoirs

Streamline-adjustment-assisted heterogeneous combination flooding is a new technology for enhanced oil recovery for post-polymer-flooded reservoirs. In this work, we first carried out a series of 2D visualization experiments for different chemical flooding scenarios after polymer flooding. Then, we explored the synergistic mechanisms of streamline-adjustment-assisted heterogeneous combination flooding for enhanced oil recovery and the contribution of each component. Test results show that for single heterogeneous combination flooding, the residual oil in the main streamline area after polymer flooding is ready to be driven, but it is difficult to be recovered in the non-main streamline area. Due to the effect of drainage and synergism, the streamline-adjustment-assisted heterogeneous combination flooding diverts the injected chemical agent from the main streamline area to the non-main streamline area, which consequently expands the active area of chemical flooding. Based on the results from the single-factor contribution of the quantitative analysis, the contribution of temporary plugging and profile control of branched preformed particle gels ranks in the first place and followed by the polymer profile control and the effect of streamline adjustment. On the contrary, the surfactant contributes the least to enhance the efficiency of oil displacement.

Water Plugging Performance of Preformed Particle Gel in Partially Filled Fractures

Preformed particle gel (PPG) treatment has been well-recognized as an efficient method to reduce excessive water production in fractured reservoirs. However, previous research on its plugging effic...

Oil recovery from fractured reservoirs using in situ and preformed particle gels in micromodel structures

Oil extraction often accompanied with relatively large amounts of water production causes several environmental and mechanical problems, particularly in oil-fractured reservoirs. One way to alleviate this problem is to use gels as a blockage agent. In this study, several micromodels with different geometries of fractures including a simple fracture, step fracture, fracture with variable mouth and fracture with a tiny crack were prepared. The amount of oil recovery was measured from these micromodels in the presence or absence of gel. In situ and preformed particle gels (PPGs) were injected into the micromodels to compare their ability in blocking fractures and increasing oil recovery. The BaCl2·2H2O salt solution was used to swell PPGs. The amount of salt concentration was optimized so that PPGs had maximum ability to block fractures. Several PPG concentrations, 1000, 2000, and 3000 ppm, were examined to optimize the amount of PPGs, which have to be injected into the micromodels. Injection flow rate was optimized so that salt water could efficiently sweep the matrix structure. Results showed that both PPG and in situ gels have a considerable effect on decreasing water production and increasing oil extraction. However, PPGs were superior in comparison to in situ gels to increase oil recovery. It was found that increasing salt concentration decreases the swelling percentage of PPGs. The optimum amount of injection flow rate was found to be 0.1 mL/hr for all the prepared micromodels. The optimum concentration of PPGs was different for each micromodel.

Effect of Network Parameters of Preformed Particle Gel on Structural Strength for Water Management

Summary Preformed particle gel (PPG) is an appropriate solution for conformance control and water management in low permeability reservoirs. In this paper, the network parameters of PPGs are evaluated through swelling tests and rheology and by determining their role in maintaining structural strength. Several PPG hydrogels were prepared by varying the concentrations of polyacrylamide and chromium triacetate [Cr(OAc)3] as copolymer and crosslinker, respectively, using a central composite design. The characterization of these hydrogels was performed using a scanning electron microscope (SEM), electron dispersion X-ray (EDX), and environmental scanning electron microscope (ESEM). The correlation between reaction conditions and the network parameters of polymer networks, such as the molecular weight of the polymer chain between two neighboring crosslinks (Mc¯), the crosslink density, and the size fraction, have been determined. In addition, swelling of the hydrogels took place through the Fickian diffusion mechanism. Structural states of Laponite dispersions strongly depend on concentration and ionic strength. Based on the rheological tests, the dynamic modulus of the PPG was strongly dependent on the initial concentration and resulting network parameters of the hydrogel. The results showed an effective interaction between Mc¯ and the elastic modulus of the gel network. Through the optimization of the network parameters, the appropriate composition was presented on the basis of the factors of strength (complex modulus of 4×104 Pa in the plateau region), the formation of a 3D network, and the preservation of the viscoelastic structure in the presence of Na+, Ca2+, and Mg2+, at a salt sensitivity of 0.5. In addition, the optimum sample structure was confirmed on the basis of microscopic images. Based on the coreflooding data, the optimal PPG showed a disproportionate permeability reduction (DPR) index of 17.01 and indicated the dual performance of these materials against water and oil. Also, the permeability diagrams of the core showed wettability of the oil-wet core could shift to more water-wet after PPG injection. To summarize this research, we present the determination and analyses of the network parameters as a novel technique for predicting the performance of hydrogels in porous media, and for investigating their strength under harsh reservoir conditions. In other words, determination of the network parameters can be used to ensure the success of the gel performance in porous media.