Relative Permeability Research Articles

Effect and mechanism of the moisture content on the kinetic retardation of LNAPL pollutant migration by the capillary zone.

Light nonaqueous-phase liquids (LNAPLs) are the main source of organic pollution in soil and groundwater environments. The capillary zone, with varying moisture contents, is the last barrier against the infiltration of LNAPL pollutants into groundwater and plays an important role in their migration and transformation. However, the effect and mechanism of the moisture content in the capillary zone on LNAPL pollutant migration are still unclear. Herein, to explore the effect of the moisture content on LNAPL pollutant migration, a series of sandbox migration experiments were simulated using diesel oil as a typical LNAPL pollutant and the capillary zones of fine and silty sand as research objects. Several numerical models were constructed based on the recorded migration process of LNAPL pollution fronts in the capillary zones of different media during experiments. The mechanism by which the moisture content in the capillary zone retarded LNAPL pollutant infiltration was revealed using a combination of the construction method of microstructural pores and the theory of multiphase flow. These findings unequivocally indicate that an increase in the moisture content leads to a decrease in the relative permeability of the NAPL phase in unsaturated media, which is the fundamental reason for the retarded kinetic migration of LNAPL pollutants. The results of this study lay a solid foundation for designing comprehensive and effective remediation strategies for LNAPL contamination in soil and groundwater.

Regression Analysis for Predicting the Magnetic Field Shielding Effectiveness of Ferrite Sheets

In this paper, a method to predict near-field magnetic shielding effectiveness (NSE) of ferrite sheets is proposed by measuring their relative permeability. The NSE prediction for ferrite sheets is developed using eight regression models based on higher-order terms of permeability, extracted through Minitab’s regression analysis using data from the measured NSE and relative permeabilities of the ferrite sheets. To analyze the accuracy of the predicted NSE in comparison to the measured NSE, the mean square error (MSE) was computed. As a result, the extracted regression models enable fast and accurate NSE predictions for ferrite sheets up to 100 MHz, achieving an MSE of less than 1.0, in contrast to numerical simulation methods that require several hours.

Green synthesized FeNPs ameliorate drought stress in Spinacia oleracea L. through improved photosynthetic capacity, redox balance, and antioxidant defense

The present study was designed to highlight the ameliorative role of iron nanoparticles (FeNPs) against drought stress in spinach (Spinacia oleracea L.) plants. A pot experiment was performed in two-way completely randomize design with three replicates. For drought stress three levels were used by maintaining field capacity of the soil. This included control (100% field capacity), moderate drought stress (D1; 50% field capacity) and severe drought stress (D2; 25% field capacity). FeNPs synthesized by green method using rice straw were applied along with precursor FeCl3, used as Fe source for the synthesis of FeNPs, through foliar spray (40 mg L− 1 for both). Growth parameters, efficiency of photosynthetic machinery, gas exchange attributes, total soluble proteins, and inorganic ions (Ca2+, K+ & Fe2+) were significantly reduced at both D1 and D2 stress levels, compared to control plants. Fe supplements in the form of FeCl3 and FeNPs improved these attributes in both control and drought conditions. Malondialdehyde, H2O2, relative membrane permeability (stress indicators) and the activities of antioxidants were increased in response to drought stress. Fe supplements further improved the antioxidant defense activities and efficiently lowered the effects of stress indicators. These effects of FeCl3 and FeNPs resulted in improved growth of S. oleracea plants in control and drought conditions. Results showed that FeNPs had more prominent effects on growth of S. oleracea plants compared to FeCl3. These findings suggest that FeNPs could be a helpful tool for lessening the harmful consequences of drought stress and this can be used for abiotic stress alleviation in other crops as well.

Calculating the water production rate in a low-saturation reservoir based on the modified curved capillary theory

Low-saturation reservoirs have complex geological backgrounds, diverse genetic mechanisms, poor physical properties, variable pore structures, and low permeabilities. It also has a wide range of oil–water coexistences and low oil saturations, which make it difficult to accurately calculate their water production rate. To address these issues, this study investigates low-saturation reservoirs in the Nanpu Sag, focusing on petrophysical characteristics and relative permeability variations in samples with different pore structures. A range of petrophysical experiments, including coupled oil-water phase percolation, petroelectrical testing, nuclear magnetic resonance (NMR), and X-ray diffraction (XRD), were conducted to analyze fluid interactions and pore structure impacts. From these experiments, a new pore structure factor was proposed to enhance the existing curved capillary theory. The results showed that this modification improved calculation accuracy for water production rate. The enhanced model was applied to actual logging data and validated against test production results, demonstrating its effectiveness. This study offers both theoretical and practical advancements. It improves the understanding of fluid dynamics in low-saturation reservoirs and provides a reliable tool for fluid identification during exploration. This model can guide more accurate reservoir assessments and support optimized production strategies, improving efficiency in managing these challenging reservoir environments.

Construction and characteristic analysis of in-situ combustion production dynamic evaluation equation based on seepage difference of zones

The combustion-displacement relationship is complex of in-situ combustion (ISC), making it difficult to assess the combustion effect on the ground. In this work, combined with the characteristics of ISC production stage and oil-gas-water relative permeability relationship, the production dynamic evaluation equations are established, such as cumulative gas-liquid, cumulative oil-water and water cut. The determination method is obtained of oil saturation and gas saturation in the oil bank. It is found that the evaluation equation is exponential in the production rising and oil bank breakthrough stage, which is linear in the stable production stage. The obtained evaluation curves can fully reflect the stage characteristics of ISC. According to the evaluation equation, the oil saturation in the oil bank of the ISC test area in Xinjiang, China is calculated to be between 0.6 and 0.72, the temperature is roughly 110 °C, and the gas saturation is 0.09. The diagnosis believes that the test area has entered the oil bank breakthrough stage in the later stage. The established evaluation equations can directly use the actual production data to diagnose the characteristics of ISC production at different stages, and can quickly provide guidance for the adjustment of field measures.

Time-varying quantitative characterization of reservoir microscopic pore structure based on digital core

The reservoir physical parameters (such as porosity, permeability, phase permeability, etc.) will change in the process of water injection development with the continuous flushing effect of high magnification water drive, which may have adverse effects on development if they cannot be accurately characterized. In this paper, we try to quantitative characterize the time -varying features of pore structure from the microscopic perspective. We used high-resolution 3D micro-CT (MCT) images to supplement the analysis of the physical properties of the rocks, and we used 3D pore network modeling technology to generate a 3D model of the rock samples. Then the relevant static micro-pore parameters are derived to study the changes of rock properties in different periods of development. Pore parameters were obtained to study the changes in porosity, permeability and pore size distribution of the rocks under different expulsion multiples, and to visualize the time-varying pattern of the microstructure of the rock samples under different stages of water injection. Under low-multiple water-driven conditions (10 PV), the physical properties of the rock samples did not change significantly, with an average facies change of only 1.98%. When reaching high multiples of water drive (more than 500PV), the change rate reaches more than 15%. And with the increase of water drive multiples, the distribution of pore radius and throat radius of rock samples showed an obvious right-shift trend, and the pores and throats increased, which was consistent with the results of CT scanning photographs. Equation fitting of the simulation results reveals that the core micro-parameters show an overall logarithmic relationship with the change of water drive. In this paper, a new application of Micro CT is provided to quantify the microstructure of water-injected reservoirs. By adopting this method, the effect of water-drive multiplicity on reservoir structure can be illustrated from a microscopic perspective. Meanwhile, compared with previous studies, this paper further investigates the effect of time-variation based on the qualitative analysis of the effect of time-variation of water-driven in reservoirs, and regresses time-variation curves and formulas through the changes in multiple water-driven states, which fills in the gap of the current lack of quantitative research and provides new understanding and optimization of the development of oilfields. The study will provide a new perspective for understanding and optimizing oilfield development.

Enhanced numerical models for two-component fluid flow in multiscale porous structures

Multi-component fluid flow simulations in multiscale porous structures, many parts of which are likely to be under-resolved at practical resolution, often require a high-fidelity numerical model to account for the contribution of under-resolved structures to the fluid flow. In previous studies, a numerical model was proposed for viscous and capillary forces from under-resolved regions. It successfully showed comparable results in absolute permeability, capillary pressure, and relative permeability when compared to an equivalent fully resolved case up to ten times higher resolution. In this study, we show further extensions of the model to handle various types of structures and to capture detailed fluid behavior. First, we introduce the controllability of surface tension in the pseudo-potential lattice Boltzmann model while keeping the interface thickness and the spurious current at the same level. This helps to resolve more detailed interface dynamics in under-resolved regions. Second, we develop a numerical model to capture the residual fluid component in the under-resolved structure. Since it is difficult to capture such cell-sized or less-than-cell-sized fluid components with diffusive interface models, we try to consider them separately using local constitutive relations, such as the absolute and relative permeability and capillary pressure curves. Third, we introduce a tensorial resistivity model to handle under-resolved heterogeneous structures, such as a fiber bundle. After calculating the principal axis for resistivity using the Hessian and the gradient of the local porosity field, the tensorial resistivity is rotated in the proper direction. Through a series of benchmark test cases, including cases using practical rock geometries, these enhancements are validated and show significant accuracy improvements with respect to the transient interface dynamics, capture of local irreducible fluid components, and directionality effects of under-resolved structures.

Instability mechanism and a fractal theory-based relative permeability model of immiscible two-phase displacement in rough fractures

The two-phase displacement in rock fractures is a critical scientific challenge in deep energy development projects, characterized by the intricate and dynamic flow patterns resulting from the complex fracture geometry and mutual interference between the two-phase fluids. The present study involves the construction of a three-dimensional rough fracture fine model using the fast Fourier transform and Gaussian distribution method. The phase field-finite element method is employed to simulate the dynamic displacement of water-oil flow and the evolution of the water-oil interface, aiming to investigate the impact of roughness, aperture, and wettability on the viscous fingering pattern observed in rough fractures. The numerical results indicate that the immiscible two-phase displacement presents a viscous fingering pattern at a high flow rate. Moreover, the greater the roughness is, the higher the number of fingering is, and the more volatile the change in displacement velocity is. The width of the wet-phase flow channel increases proportionally with the fracture aperture increasing. Furthermore, the morphology of immiscible two-phase interface within fractures is also influenced by the wetting angle, and the fingering, bifurcation, and crushing phenomena appear in the oil-wet state with the strong displacement interface instability. Finally, a fractal model of relative permeability for waterflooding in rough fractures is proposed based on the cubic law of flow and fractal dimension of aperture distribution, which has been validated through comparison with numerical results.

Application of indole-3-butyric acid (IBA) enhances agronomic, physiological and antioxidant traits of Salvia fruticosa under saline conditions: a practical approach.

Salinity stress is a significant challenge in agriculture, particularly in regions where soil salinity is increasing due to factors such as irrigation practices and climate change. This stress adversely affects plant growth, development, and yield, posing a threat to the cultivation of economically important plants like Salvia fruticosa. This study aims to evaluate the effectiveness by proactively applying indole-3-butyric acid (IBA) to Salvia fruticosa cuttings as a practical and efficient method for mitigating the adverse effects of salinity stress. The factors were arranged as three different IBA doses (0, 1, and 2 g/L) and four different salinity concentrations (0, 6, 12, and 18 dS/m) in controlled greenhouse conditions. Plant height (PH), flower spike length (FSL), fresh shoot length (FRL), root length (RL), fresh root weight (FRW), fresh shoot weight (FSW), dried root weight (DRW), dried shoot weight (DSW), root/shoot index, drog (g/plant), relative water content (RWC), relative membrane permeability (RMP), chlorophyll content (SPAD), extraction yield (%), DPPH (2,2-Diphenyl-1-picrylhydrazyl), phenol content, flavonoid content, and ABTS (2,2'-Azino-bis (3-ethylbenzothiazoline-6-sulfonic acid)) values were measured. The results show that as salinity doses increased, all parameters showed a decline. However, with a one-time IBA application to the plant cuttings before the rooting stage, particularly at a concentration of 2 g/L, was effective for mitigating the negative effects of salinity stress. Across all measured parameters, IBA significantly reduced the adverse impacts of salinity on Salvia fruticosa.

Impact of Relative Permeability Hysteresis on CO2 Storage in Saline Aquifers

ABSTRACTThe urgent challenge of climate change, driven by rising carbon emissions, necessitates innovative strategies for carbon capture and storage (CCS). This study examines the impact of hysteresis in relative permeability on CO2 entrapment efficiency within saline aquifers, known for their significant storage capabilities. An aquifer model was analyzed through numerical simulation by varying hysteresis values from 0.2 to 0.5 to evaluate their impact on CO2 plume behavior, retention during water‐alternating‐gas (WAG) injection, and plume morphology. The CO2 plume exhibits a funnel‐shaped configuration at low hysteresis with a narrow, pointed base, indicating a concentrated upward migration trajectory. In contrast, a hysteresis value of 0.5 results in diminished gas movement toward the upper aquifer, transforming the plume into a more oval shape. Results from the land trapping model further support our findings, revealing an inverse relationship where increased hysteresis enhances residual CO2 entrapment, reflected in trapping coefficient values ranging from 0.5 to 4. This underscores the model's efficacy in verifying gas trapping efficiency and safety during sequestration. Moreover, increased water flow generates stronger forces, pushing CO2 into narrower pore spaces, where it becomes trapped. Our findings indicate that increased hysteresis enhances CO2 retention by limiting vertical migration and significantly influences plume geometry, promoting stable and predictable distribution patterns. At higher hysteresis values, CO2 migration is significantly restricted, resulting in near‐complete immobilization of the injected gas. This research highlights hysteresis's critical role in refining injection methodologies and enhancing plume stability for long‐term CO2 storage. © 2024 Society of Chemical Industry and John Wiley & Sons, Ltd.

Optimization of the separation chamber structure of a pneumatic dry low-intensity drum magnetic separator based on a multi-physical field coupling model

ABSTRACT Dry magnetic separator is the workhorse for processing fine-grained magnetite in arid and remote regions. In this study, a pneumatic dry low-intensity drum magnetic separator (PDLDMS) with a side vertical upward feeding was designed and optimized based on a multiphysics numerical model. The structural parameters of the separation chamber were designed and optimized by predicting the separation performance and particle dynamic trajectory of the PDLDMS. All predictions indicated that the structural parameters of the separation chamber affected the capture behavior of particles with different sizes and relative magnetic permeability. An appropriate increase in the spacing of the separation chamber was conducive to reducing the entrapment of the particles with a lower relative magnetic permeability and improving the grade of the concentrate. An appropriate increase in the waveform amplitude of the separation chamber was conducive to improving the recovery of the fine-grained particles with a higher relative magnetic permeability and improving the recovery of the concentrate. The optimum PDLDMS performance was achieved at a separation chamber spacing of 40 mm and a separation chamber waveform amplitude of 20 mm. By comparing the experimental results with simulated results, the accuracy of the PDLDMS recovery and grade prediction results were verified.

Enhanced technique for analyzing waterflooding characteristic curve in water-bearing gas reservoirs considering the influence of water-sealed gas

ABSTRACT Considering the water-sealed gas effect in water-bearing gas reservoirs, this study integrates the heterogeneity coefficient (A) and the water influx coefficient (B) to quantify the water-sealed reserves precisely. Building upon this, a novel waterflooding characteristic curve equation is proposed by merging the material balance equation with the relative permeability model. Sensitivity analyses of the theoretical curve reveal that an increase in both the heterogeneity coefficient (A) and the water influx coefficient (B) exacerbates the water-sealed effect, prematurely and steeply elevating the waterflooding characteristic curve; this leads to a higher water-gas ratio. The results demonstrate that the proposed curve, which accounts for the water-sealed phenomenon, aligns well with production data throughout the entire development phase, enabling an effective assessment of gas reservoir exploitation efficiency and forecasting of water-gas ratios. This research enhances the versatility of waterflooding characteristic curve, improving the precision of water production forecasts and providing a robust foundation for water management strategies. Therefore, it has significant practical implications.

ЭФФЕКТИВНОСТЬ ПРИМЕНЕНИЯ ФИЗИЧЕСКОГО ВОЗДЕЙСТВИЯ НА ПРОДУКТИВНЫЙ ПЛАСТ ДЛЯ УВЕЛИЧЕНИЯ НЕФТЕОТДАЧИ ПЛАСТОВ

This article assessed the technical and economic efficiency of using physical impact on the productive formation in one of the fields in Western Kazakhstan. World experience in using this technology in fields testifies to its high technological efficiency. To optimize oil production, changes in oil viscosity, increase in oil production, and decrease in water content were analyzed. All Cretaceous horizons are characterized by good reservoir properties. However, the high viscosity of oil and insufficient cementation of the rocks forming the horizons limit the complete extraction of the product. The determination of phase permeabilities in the oil-water system was carried out in laboratory conditions during stationary filtration. As a result of the use of physical impact, the viscosity of oil decreased by almost half, from 700 cP to 480 cP, which helps to increase oil production and reduce the water content in the produced products.

Assessment of Two Crosslinked Polymer Systems Including Hydrolyzed Polyacrylamide and Acrylic Acid-Hydrolyzed Polyacrylamide Co-Polymer for Carbon Dioxide and Formation Water Diversion Through Relative Permeability Reduction in Unconsolidated Sandstone Formation.

One of the most challenging aspects of manipulating the flow of fluids in subsurfaces is to control their flow direction and flow behavior. This can be especially challenging for compressible fluids, such as CO2, and for multiphase flow, including both water and carbon dioxide (CO2). This research studies the ability of two crosslinked polymers, including hydrolyzed polyacrylamide and acrylic acid/hydrolyzed polyacrylamide crosslinked polymers, to reduce the permeability of both CO2 and formation water using different salinities and permeability values and in the presence of crude oil under different injection rates. The result showed that both polymers managed to reduce the permeability of water effectively; however, their CO2 permeability-reduction potential was much lower, with the CO2 permeability reduction being less than 50% of the water reduction potential in the majority of the experiments. This was mainly due to the high flow rate of the CO2 compared to the water, which resulted in significant shearing of the crosslinked polymer. The crosslinked polymers' swelling ratios were impacted differently based on the salinity, with the maximum swelling ratio being 9.8. The HPAM polymer was negatively affected by the presence of crude oil, whereas increasing salinity improved its performance greatly. All in all, both polymers had a higher permeability reduction for the formation water compared to CO2 under all conditions. This research can help improve the applicability of CO2-enhanced oil recovery and CO2 storage in depleted oil reservoirs. The ability of the crosslinked polymers to improve CO2 storage will be a main focus of future research.

Uncertainty Quantification on Foam Modeling: The Interplay of Relative Permeability and Implicit-texture Foam Parameters

Uncertainty Quantification on Foam Modeling: The Interplay of Relative Permeability and Implicit-texture Foam Parameters

Microemulsion for stimulating wells with high gas and water cut

This article is the first to suggest that microemulsions can also be used to reduce gas and water saturation in the reservoir in the process of well stimulation. This article presents the results of an experimental study on the possibility of using a multifunctional microemulsion for well stimulation at a bottomhole pressure below the saturation pressure and high water cut. It has been found that the treatment of the bottomhole zone with the developed microemulsion leads to a significant reduction in the size of gas bubbles due to a decrease in interfacial tension, which facilitates their removal from the bottomhole zone and increases hydraulic diffusivity of the porous medium for oil approximately five times. In addition, adsorption of the composition on the pore walls, changes the wettability of the walls from oil-wet to the water-wet providing a sliding surface for the oil. The increase in phase permeability for oil, which is proportional to the hydraulic diffusivity and the wettability alteration enhance the oil flow rate by 13.5% and consequently oil recovery by 21%. In order to visualize the effect of microemulsion the simulation of oil flow through porous media was performed using COMSOL Multiphysics.

Modeling Approach to Mechanical Gas Dewatering of Filter Cakes With Non‐Uniform Cake Height

AbstractGas dewatering of filter cakes with non‐uniform cake height is investigated. Two‐phase fluid flow is described in a continuum approach by conservation of mass and momentum of both phases. A priori measurements of capillary pressure and relative permeability allow to predict the impact of different cake geometries on the dewatering kinetics. Transient saturation and flow velocity fields within the filter cakes are calculated and discussed. No measurable effect on the mean saturation is observed in the investigated cases. However, the total flux, which needs to be handled by the vacuum pump to prevent a drop of the pressure difference during gas dewatering, is affected significantly by cake geometry. Model predictions are compared to experimental data from preceding publications and show reasonable agreement within the margin of error.

A novel method for estimating gas and liquid saturation according to the change of temperature field

Nitrogen foam treatment is widely used to control water production in oil wells by selectively reducing water phase relative permeability in oil-water-transition zone. A novel method is proposed to analyze nitrogen gas saturation distribution under varying foam generation pressure drops, which the heat conduction coefficients and heat capacities of nitrogen gas and water are considered. A one-dimensional sand pack model was used to evaluate the impact of gravity on gas saturation distribution, tested in both horizontal and vertical orientations. The gas and water saturation varying along the flow direction of the tube can be calculated according to temperature change. The results indicate that nitrogen injection with pressure drops of 0.9 and 1.2 MPa can generate more evenly gas and water distribution as well as longer foam flow distance comparing to the higher injection pressure drops of 1.5 MPa. Average gas saturation generated in the vertical manner is found to be lower than that of horizontal one due to the higher gas flow resistance in the vertical direction. The simulation result of gas saturation distribution along the tube using Fluent software matches the experimental results well.

Modeling of a Novel T-Core Sensor with an Air Gap for Applications in Eddy Current Nondestructive Evaluation.

Multi-layer conductive structures, especially those with features like bolt holes, are vulnerable to hidden corrosion and cracking, posing a serious threat to equipment integrity. Early defect detection is vital for implementing effective maintenance strategies. However, the subtle signals produced by these defects necessitate highly sensitive non-destructive testing (NDT) techniques. Analytical modeling plays a critical role in both enhancing defect-detection capabilities and guiding the design of highly sensitive sensors for these complex structures. Compared to the finite element method (FEM), analytical approaches offer advantages, such as faster computation and high accuracy, enabling a comprehensive analysis of how sensor and material parameters influence defect detection outcomes. This paper introduces a novel T-core eddy current sensor featuring a central air gap. Utilizing the vector magnetic potential method and a truncated region eigenfunction expansion (TREE) method, an analytical model was developed to investigate the sensor's interaction with multi-layer conductive materials containing a hidden hole. The model yielded closed-form expressions for the induced eddy current density and coil impedance. A comparative study, implemented in Matlab, analyzed the eddy current distribution generated by T-core, E-core, I-core, and air core sensors under identical conditions. Furthermore, the study examined how the impedance of the T-core sensor changed at different excitation frequencies between 100 Hz and 10 kHz when positioned over a multi-layer conductor with a hidden air hole. These findings were then compared to those obtained from E-core, I-core, and air-core sensors. The analytical results were validated through finite element simulations and experimental measurements, exhibiting excellent agreement. The study further explored the influence of T-core design parameters, including the air gap radius, dome radius, core column height, and relative permeability of the T-core material, on the inspection sensitivity. Finally, the proposed T-core sensor was used to evaluate crack and hole defects in conductors, demonstrating its superior sensitivity compared to I-core and air core sensors. Although slightly less sensitive than the E-core sensor, the T-core sensor offers advantages, including a more compact design and reduced material requirements, making it well-suited for inspecting intricate and confined surfaces of the target object. This analytical model provides a valuable tool for designing advanced eddy current sensors, particularly for applications like detecting bolt hole defects or measuring the thickness of non-conductive coatings in multi-layer conductor structures.

Water and Oil Volume Measurement Using UV–Visible Spectroscopy

Fluid saturation in relative permeability experiments is typically determined by volumetric or gravimetric measurements, as well as in-situ saturation monitoring (ISSM). Gravimetric measurements tend to have larger error due to grain loss. The conventional volumetric method used can be a challenge because produced volumes for oil and water must be separated and measured manually. ISSM method is also a costly technique. In this study, an UV–visible spectroscopy was used to continuously and cost effectively measure oil and water volumes. A water-oil unsteady state relative permeability was performed to investigate the feasibility of calculating oil and water volumes using UV–visible spectroscopy. UV–visible spectroscopy is a quantitative technique in analytical chemistry to determine concentrations of known solutes. A UV–visible spectroscope was located in the flow line immediately after the core holder and used to quantify fluid volumes (oil and water) produced from a core sample during unsteady state relative permeability study. A volumetric separator was also used to compare production volumes obtained from UV–visible spectroscope. The relative permeabilities were calculated using JBN method from both volumetric and UV-visible spectroscope measurements and then history matched with Sendra (PRORES AS). The final oil volume produced, oil and water relative permeability curves obtained from UV–visible spectroscope measurements were in good agreement with volumetric measurements. The Corey relative permeability curves simulated from Sendra also were closely matched with analytical relative permeability curves obtained using volume measurements from volumetric and UV–visible spectroscope data. Nuclear Magnetic Resonance (NMR) on post relative permeability experiment was also in good agreement with UV–visible spectroscope measurement. UV–visible spectroscopy was also used to measure the breakthrough time of the injected fluid. Breakthrough time estimated using in-line UV–visible spectrophotometer was 0.634 PVI compared to 0.617 and 0.673 PVI from pressure data and volumetric observations.Graphic