Oil Swelling Research Articles

Mechanical properties, water absorption, and swelling behaviour of rice husk powder filled polypropylene/recycled acrylonitrile butadiene rubber (PP/NBRr/RHP) biocomposites using silane as a coupling agent

The performance of rice husk powder (RHP) filled polypropylene (PP)/ recycled acrylonitrile butadiene rubber (NBRr) biocomposites with and without coupling agent, γ-aminopropyltrimethoxysilane (APS), were investigated. The composites with different RHP filler loading (0 to 30 phr) were prepared in a Haake internal mixer. Mechanical properties, swelling behavior, and water absorption of PP/NBRr/RHP were studied. Increasing RHP loading in PP/NBRr/RHP biocomposites increased processing torque, tensile modulus, water absorption, and swelling in oil but decreased the tensile strength and elongation at break of the biocomposites. The γ-APS treated RHP composites exhibited higher processing torque, tensile strength, and tensile modulus but lower elongation at break when compared to untreated RHP composites. This is due to strong bonding between γ-APS treated RHP filler and PP/NBRr matrices. These findings were well supported by micrographs from the morphology studies. The γ-APS treatment on RHP improved the adhesion between RHP fiber and PP/NBRr polymer matrices, which led to less water and oil absorption into PP/NBRr/RHP/ biocomposites.

Peroxide cured natural rubber/fluoroelastomer/high-density polyethylene via dynamic vulcanization

In this work, blends of fluoroelastomer (FKM), natural rubber (NR) along with high-density polyethylene (HDPE) by dynamic vulcanization using peroxide (DBPH, DCP) as a curing agent were prepared. HDPE was melt-mixed with NR and FKM at different compositions (HDPE/FKM/NR i.e. 30/60/10, 30/55/15, 30/50/20, and 30/35/35%wt) using an internal mixer at 150°C and 50 rpm rotor speed. The mechanical properties and oil swelling resistances of these blends were analyzed according to ISO 37 (Type 1) and ASTM D471, respectively. The results suggest that DBPH works better as a curing agent for the dynamic vulcanization system than DCP. The optimum mechanical properties and oil resistance were revealed in 30/50/20 and 30/60/10 HDPE/FKM/NR, being dynamic vulcanized with DBPH, respectively. In addition, was found that a dispersed HDPE phase shows the percent crystallinity in the range of 53% to 55% upon increasing the NR content. The SEM micrographs reveal the NR phase is well dispersed in FKM as small particles. POLYM. ENG. SCI., 2011. © 2011 Society of Plastics Engineers .

Anisotropic magnetic microparticles from ferrofluid emulsion

A simple synthetic approach for the preparation of anisotropic Janus-like sub-micrometre sized hybrid magnetic particles consisting of inorganic superparamagnetic iron oxide nanoparticles and an organic polymer is demonstrated here. Two-step controlled processes, (a) the swelling of preformed magnetic oil in water ferrofluid droplets with styrene and (b) a seed emulsion polymerization of styrene in the presence of monomer swollen ferrofluid as seed, were accomplished. The swelling of ferrofluid droplets with styrene was investigated by gas chromatography (GC) to point out the partition of styrene in the continuous aqueous phase and in the droplets’ organic phase. A series of seed emulsion polymerizations initiated by AIBN and KPS in different concentrations of styrene was carried out in order to turn the monomer swollen ferrofluid droplets into the magnetic polymer particles having two different phases. This approach allows us to investigate the effect of the seed to monomer ratio and especially the initiator type on the anisotropic morphology of the prepared particles. Most importantly, we demonstrated that the used experimental method enables one to produce magnetic Janus hybrid particles. The independent phase of the anisotropic Janus particle morphology was evidenced by transmission electron microscopy (TEM). The complete characterization of particles was performed using light scattering measurement, thermogravimetric analysis (TGA) and size-exclusion chromatography to explain the properties of such “biphasic” microparticles. An interpretation based on thermodynamics and a proposed tentative polymerization mechanism is also discussed. This procedure can be adopted to produce large quantities of magnetic anisotropic submicron colloidal particles for biotechnological applications.

Investigation of Cyclic Solvent Injection Process for Heavy Oil Recovery

Summary This paper summarizes numerical and experimental simulation results of a cyclic solvent injection process study, which was part of a continuing investigation into the use of solvents as a follow-up process in Cold Lake and Lloydminster reservoirs that have been pressure-depleted by cold heavy oil production with sand (CHOPS). Typically only 5% - 10% of the original oil in place (OOIP) is recovered during cold production; therefore, an effective follow-up process is required. The cyclic solvent injection (CSI) experiment consisted of primary production followed by six solvent (28% C3H8 - 72% CO2) injection cycles. Oil recovery after primary production and six solvent cycles was 50%, which indicates the potential viability of the CSI process. Concurrently with the laboratory physical simulation, a numerical simulation model was developed to represent the physical behaviour of the experimental results. A history match of the primary production portion of the experiment was obtained using an Alberta Innovates - Technology Futures (AITF) foamy oil model. This resulted in the characterization (fluid saturations and pressures) of the oil sandpack at the start of the solvent injection process. The history match of the subsequent six solvent injection cycles was used to validate the numerical model of the CSI process developed at AITF. This model includes nonequilibrium rate equations that simulated the delay in solvent reaching its equilibrium concentration as it dissolves or exsolves in the oil in response to changes in the pressure and/or gas-phase composition. Dissolution of CH4, C3H8 and CO2 in oil and CO2 in water were considered, as was exsolution of CH4, C3H8 and CO2 from oil and CO2 from water. Reduced gas-phase permeabilities resulting from gas exsolution were also included. The history match simulations indicated that: The important mechanisms were represented in the simulations. Significant oil swelling by solvent dissolution occurs during solvent injection periods. This can reduce solvent injectivity and penetration into a heavy oil reservoir during solvent injection periods. Low oil and gas-phase relative permeabilities are required during production periods to match the experimental oil and gas production during solvent cycles. A parametric simulation study showed that the quantity of gas injected in an injection period was relatively insensitive to the oil-phase diffusion coefficients, but was sensitive to solvent solubility in oil, dissolution rates, gas-phase diffusion coefficients, molar densities in the oil phase, gas-phase relative permeability and capillary pressure. It was shown that oil production is highly dependent on how quickly solvent can dissolve in the oil during injection and exsolve from the oil during production.

Experimental Study of Pore-Scale Mechanisms of Carbonated Water Injection

Carbon dioxide (CO2) injection is a well-established method for increasing recovery from oil reservoirs. However, poor sweep efficiency has been reported in many CO2 injection projects due to the high mobility contrast between CO2 and oil and water. Various injection strategies including gravity stable, WAG and SWAG have been suggested and, to some extent, applied in the field to alleviate this problem. An alternative injection strategy is carbonated water injection (CWI). In CWI, CO2 is delivered to a much larger part of the reservoir compared to direct CO2 injection due to a much improved sweep efficiency. In CWI, CO2 is used efficiently and much less CO2 is required compared to conventional CO2 flooding, and hence the process is particularly attractive for reservoirs with limited access to large quantities of CO2 (offshore reservoirs or reservoirs far away from inexpensive natural CO2 resources). This article describes the results of a pore-scale study of the process of CWI by performing high-pressure visualisation flow experiments. The experimental results show that CWI, compared to unadulterated (conventional) water injection, improves oil recovery as both a secondary (before water flooding) and a tertiary (after water flooding) recovery method. The mechanisms of oil recovery by CWI include oil swelling, coalescence of the isolated oil ganglia and flow diversion due to flow restriction in some of the pores as a result of oil swelling and the resultant fluid redistribution. In this article the potential benefit of a subsequent depressurisation period on oil recovery after the CWI period is also investigated.

Fontes de óleo e níveis de suplementação de vitamina E na ração sobre a qualidade do sêmen suíno acondicionado a 17 e 5ºC

Objetivou-se avaliar o efeito da adição de fontes de óleo e dos níveis de suplementação de vitamina E na ração sobre as características do sêmen suíno resfriado a 17ºC e 5ºC. Foram utilizados 24 suínos machos reprodutores Dalboar 85 distribuídos em delineamento inteiramente casualizado, em arranjo fatorial 2 x 3, com duas fontes de óleo (soja e salmão) e três níveis de antioxidantes (150, 300 e 450 mg de vitamina E/kg). Nos animais sob suplementação com óleo de salmão, a motilidade e o teste hiposmótico dos espermatozoides após 24, 48 e 72 horas foram superiores aos observados nos animais alimentados com a ração com óleo de soja. O óleo de salmão aumentou o vigor em ambas as temperaturas avaliadas após 24 e 48 horas. A ocorrência de anormalidades morfológicas totais foi maior no sêmen dos animais sob suplementação com óleo de soja e resfriado a 17ºC, enquanto na menor temperatura de resfriamento (5º) não houve diferença entre os animais sob suplementação. A morfologia anormal no sêmen a 5ºC foi maior que no sêmen resfriado a 17ºC. O óleo de salmão melhora as características espermáticas do sêmen suíno resfriado a 17 e 5ºC durante 24 a 48 horas.

Electron‐beam irradiation of blends of polypropylene with recycled acrylonitrile‐butadiene rubber

AbstractOne‐mm thick sheets were prepared from blends of polypropylene and recycled acrylonitrile‐butadiene rubber (rNBR) with different blend ratios. Trimethylolpropane triacrylate (TMPTA) was used as a co‐agent. Electron‐beam‐initiated cross‐linking of the sheets was carried out at a dose of 40 kGy, and 3 phr of TMPTA based on the weight of rNBR was used. Properties such as tensile strength, Young's modulus, elongation at break, swelling percentage in oil, and morphology were studied. The results showed that the tensile properties had been improved by irradiation. The studies of swelling in oil revealed a higher cross‐link density in the irradiated blends compared to that in nonirradiated blends at similar blend ratios. Scanning electron microscopy studies revealed better adhesion between the phases and rough failure surfaces with a large number of tear lines which indicated a higher energy requirement for the failure of irradiated blends compared to that for nonirradiated blends. J. VINYL ADDIT. TECHNOL., 2010. © 2010 Society of Plastics Engineers

Effect of inorganic additives on some properties of NBR vulcanizates

PurposeThe purpose of this paper is to study the effect of incorporating some inorganic fillers, namely aluminium oxide and aluminium hydroxide on the rheological, mechanical and thermal behaviour of acrylonitrile‐butadiene rubber (NBR) vulcanizates.Design/methodology/approachFor improving physico‐mechanical properties of NBR vulcanizates, various compositions were made by incorporating different concentrations of employed fillers with NBR. These properties included the torque, cure time, tensile strength, elongation at break, swelling, diffusivity, as well as thermal behaviour of the loaded and unloaded NBR with fillers were characterised.FindingsThe incorporation of the two investigated fillers improves the thermal behaviour of the vulcanizates, especially aluminium hydroxide. All samples showed more or less a first order decomposition kinetics, for which the activation energy ranged from 177 to 187 kg/mol.Research limitations/implicationsNBR is extensively used industrially for its single, most important property, which is an exceptional resistance to attack by oils and solvents. However, incorporation of fillers in (NBR) leads to the development of improved, competitive properties of the vulcanizate. A further study must be carried out on the flame retarding effect of the fillers, beside the effect of surface treatment of the fillers on the dispersibility and physico‐mechanical properties of the vulcanizates.Practical implicationsThe use of two investigated fillers provided a simple and practical solution to improving the resistance to swelling in motor and break oil as well as the thermal behaviour of the NBR.Originality/valueThe use of these fillers was novel and could be used in many rubber industries especially in gasket and oil seals.

Experimental Investigation of Immiscible Gas Process Performance for Medium Oil

Abstract Immiscible CO2 injection is a potentially viable method of enhanced oil recovery (EOR) for medium oil reservoirs in southwestern Saskatchewan. The relatively high reservoir pressures could result in a large extent of CO2 dissolution, significant oil viscosity reduction and oil swelling. Laboratory corefloods were used to compare the performance of different modes of CO2 injection into a medium-gravity oil system. The following methods were compared: injection of a single CO2 slug chased by water, simultaneous injection of water/CO2, and different water-alternating-gas (WAG) cycles. The results indicate that both a single CO2 slug and the first WAG cycle in a series produced oil very efficiently, possibly owing to good gas/oil contact at the relatively high residual oil saturation at this stage. The simultaneous injection of water/CO2 was not as effective as a single CO2 slug, possibly because the co-injected water shielded the oil from being contacted by the gas. Among the four runs, a coreflood with four WAG cycles recovered the most incremental oil—20.58% initial oil in place (IOIP)—while the co-injection process produced the least (8.91% IOIP). This experimental study suggests that the immiscible CO2 EOR process is viable for medium oil reservoirs with relatively high pressures, and that proper process application is important for maximizing additional oil production. Introduction Miscible/immiscible CO2 flooding is an increasingly popular EOR technique. So far, most of the CO2 miscible/immiscible processes have been applied in light oil reservoirs, and there has been little application in medium oil reservoirs. The in-place resources of medium oils, defined as 20 - 30°API, in Saskatchewan are estimated at up to 1,338 × 106 m3 (8.42 billion barrels)(1). Most of these reservoirs are characterized by thin pay (2 to 10 metres in thickness) and shaly sand, and they have been under production for over four to five decades. The estimated average recovery by conventional waterflood, as listed in Table 1, is only approximately 23% IOIP because this method has generally exhibited early water breakthrough and high water cuts owing to the unfavourably high water-to-oil mobility ratio. By adapting miscible/immiscible CO2 flooding technologies that have matured in light oil applications, the immiscible CO2 process is potentially viable for recovering additional oil from these medium oil reservoirs if we can improve its displacement and sweep efficiency(2).

Is High-Pressure Air Injection (HPAI) Simply a Flue-Gas Flood?

Abstract High-pressure air injection (HPAI) is an enhanced oil recovery (EOR) process in which compressed air is injected into a deep, light-oil reservoir, with the expectation that the oxygen in the injected air will react with a fraction of the reservoir oil at an elevated temperature to produce carbon dioxide. Over the years, HPAI has been considered a simple flue-gas flood, giving little credit to the thermal drive as a production mechanism. The truth is that, although early production during a HPAI process is mainly due to re-pressurization and gasflood effects, once a pore volume of air has been injected the combustion front becomes the main driving mechanism. This paper presents laboratory and field evidence of the presence of a thermal front during HPAI operations, and of its beneficial impact on oil production. Production and injection data from the Buffalo Field, which comprises the oldest HPAI projects currently in operation, were gathered and analyzed for this purpose. These HPAI projects definitely do not behave as simple immiscible gasfloods. This study shows that a HPAI project has the potential to yield higher recoveries than a simple immiscible gasflood. Furthermore, it gives recommendations about how to operate the process to take advantage of its full capabilities. Introduction High-Pressure Air Injection (HPAI) is an emerging technology for the enhanced oil recovery (EOR) of light oils that has proven to be a valuable process, especially in deep, thin, low-permeability reservoirs(1-7). A number of successful high-pressure air injection projects in light oil reservoirs have been documented in the literature(8-10). Most of these projects have been operating for many years, attesting to their technical and economic success. The improvement in recovery of light oil by HPAI involves a combination of complex processes, each contributing to the overall recovery. These processes include flue gas sweeping, field re-pressurization, oil swelling, viscosity reduction, stripping of the lighter components of the oil, and thermal effects. Early production during the HPAI process is related to re-pressurization and gasflood effects; hence, the influence of the thermal zone is secondary during the early life of an injector. The oil displaced directly by the thermal front will depend on the effectiveness of the generated flue gas on oil displacement from outside the thermal region.

Life Cycle Inventory of CO2 in an Enhanced Oil Recovery System

Enhanced oil recovery (EOR) has been identified as a method of sequestering CO(2) recovered from power plants. In CO(2)-flood EOR, CO(2) is injected into an oil reservoir to reduce oil viscosity, reduce interfacial tension, and cause oil swelling which improves oil recovery. Previous studies suggest that substantial amounts of CO(2) from power plants could be sequestered in EOR projects, thus reducing the amount of CO(2) emitted into the atmosphere. This claim, however, ignores the fact that oil, a carbon rich fuel, is produced and 93% of the carbon in petroleum is refined into combustible products ultimately emitted into the atmosphere. In this study we analyze the net life cycle CO(2)emissions in an EOR system. This study assesses the overall life cycle emissions associated with sequestration via CO(2)-flood EOR under a number of different scenarios and explores the impact of various methods for allocating CO(2) system emissions and the benefits of sequestration.

An Experimental Study on Three-Phase Flow in High Pressure Air Injection (HPAI)

Abstract High Pressure Air Injection (HPAI) is an improved oil recovery process in which compressed air is injected into typically deep, light oil reservoirs. Part of the oil reacts exothermically with the oxygen in the air to produce flue gas (mainly composed of nitrogen, carbon dioxide and water). Literature explaining the reaction mechanisms and phase interactions is available. Nevertheless, little effort has been devoted to describing gas, oil and water three-phase flow behaviour under HPAI reservoir conditions. Three coreflood experiments were conducted on Berea sandstone core. The first experiment consisted of injecting flue gas into core at initial oil and connate water saturations to obtain liquid-gas relative permeability data. The second experiment was designed to evaluate oil re-saturation, after gas sweep, simulating an HPAI thermal front. The third experiment consisted of gas displacing both oil and water completing the data necessary to plot the three-phase relative permeability curves. Reservoir simulation was used to adjust relative permeability curves and hysteresis parameters by matching the pressure drop and production data. Introduction It is well-known that the oil recovery mechanisms in HPAI are a combination of highly efficient displacement by the reaction front and light oil/flue gas compositional interactions, such as oil swelling and/or vapourization and near-miscible behaviour(1). However, the contribution of each of these recovery mechanisms has not been properly assessed(2). Although significant effort has been devoted to the characterization of oxidation kinetics(3–5) and flue gas/light oil compositional interactions(6, 7), the process remains challenging to simulate even under controlled and ideal conditions, i.e., a combustion tube test. Some of the difficulties include the limited availability of experimental data to feed the numerical simulators with the required parameters, as well as the interdependence of these parameters and their variation with temperature. Assuming that these difficulties can be overcome by carrying out a study that allows a judicious analysis of experimental information and a careful treatment of the matched parameters in a numerical simulator, there is still a piece of information that has a strong influence on the simulation results and cannot be defaulted or left as a final matching tool: relative permeability. In an earlier study(2), it was suggested that for a combustion tube match, the steps previous to air injection (waterflood and inert gas flood) could be used to find a full set of relative permeability curves for the run. It was also pointed out that the rock-fluid dataset should include a variation of relative permeability data with interfacial tension to account for changes in pressure, composition, and most importantly, temperature. While this being necessary, it is still insufficient to ensure a correct representation of the flow of phases in a porous medium subjected to HPAI. Ahead of the reaction front, the high mobility flue gas (mainly composed of nitrogen and carbon oxides) displaces oil and water at nearly reservoir temperature, while in the high temperature zone, oil and water are evapourated to later condense downstream. In both zones, three-phase flow is occurring.

Desenvolvimento de elastômeros termoplásticos vulcanizados (TPV) a base de polipropileno com resíduo de pneu: I - Planejamento fatorial de experimentos

O uso do pó de pneu em misturas com termoplásticos possibilita a formação de novos materiais. Nesse trabalho o uso do pó de pneu foi caracterizado pelo planejamento fatorial completo 2³, com ponto central, em misturas com polipropileno (PP), para desenvolvimento de novos elastômeros termoplásticos vulcanizados dinamicamente (TPVs), contendo material reciclado. Os fatores utilizados neste estudo foram, pó de pneu, peróxido de dicumila e bismaleimida (em três níveis, sendo um deles, o ponto central). O planejamento foi construído para avaliar os efeitos dos fatores (principais e suas interações) nas respostas de tração, alongamento e inchamento em óleo. Os resultados mostraram que o teor de pó de pneu é predominante para melhorar o desempenho das misturas. A resistência ao inchamento é aproximadamente 150% superior em algumas formulações.

Monitoring and Predicting CO2 Flooding Using Material Balance Equations

Abstract In order to operate a CO2 flooding scheme successfully, it is necessary to get accurate information about the reservoir dynamic performance and the fluids injected. Although some numerical simulation studies have been conducted, the complicated drive mechanisms and actual reservoir performance have not been fully understood. Thus, there is a strong industrial need to develop models using different perspectives to provide valuable and complementary insights into the reservoir performance during the CO2 flooding process. The objective of this study is to develop models using material balance equations (MBE) to analyze the field data before and after CO2 injection. After matching the historical field data, the proposed model can be applied to evaluate, monitor and predict the overall reservoir dynamic performance during the CO2 flooding process. To accurately account for the complex displacement process involving compositional effect and multiphase flow, the PVT properties of reservoir fluids and the four-phase fluid relative permeability relationship are integrated into the model. This study has investigated the effects of a number of factors, such as the reservoir pressure, the amount of CO2 injected, the CO2 partition ratios in reservoir fluids, the possibility of the existence of a free CO2 gas cap, the proportion of reservoir fluids contacted by CO2, the oil swelling and the oil relative permeability improvement. The model has been applied to analyze the Weyburn CO2 flooding project. The study has shown that the proposed MBE model is an effective complementary tool to analyze overall reservoir performance in tertiary CO2 recovery processes. The results show that:there exists a free CO2 gas cap under reservoir conditions, even if the reservoir pressure is larger than MMP (minimum miscible pressure) in the Weyburn Field;the CO2 partition ratios in oil, water and gas phases and the proportions of reservoir fluids contacted by CO2 largely affect the drive mechanism and production performance; andthe effect of CO2 solubility in water under actual reservoir conditions cannot be neglected. The proposed new model is the first one in developing and applying MBE to evaluate the overall dynamic performance for the CO2 flooding process and a valuable insight into reservoir responses during this process has been achieved. Introduction CO2 flooding is considered one of the most effective tertiary recovery processes in light/medium oil reservoirs and has achieved widespread use in the petroleum industry. However, the complicated displacement mechanisms and reservoir performance involved in the CO2 injection process have not been completely understood. Monitoring reservoir performance and obtaining accurate information regarding reservoir fluid and injected fluid using field data will help understand the mechanisms and manage the CO2 injection project efficiently. There are two types of methods that monitor and evaluate reservoir performance: numerical simulation and MBE. MBE is a classic reservoir engineering tool. It is applied to analyze the reservoir performance based on the law of conservation of matter. Compared with MBE, reservoir numerical simulation is a more modern technique for modelling reservoir performance.

14N NMR spectra of molecular nitrogen in SDS/pentanol swollen lamellar phases

14N NMR spectra of air dissolved in lyotropic mesophases are reported. In order to observe the whole spectrum from a molecule in which the quadrupole coupling constant is on the order of a few megahertz, a weak alignment degree with respect to the magnetic field is mandatory. Therefore, dilute lyotropic liquid crystals, namely sodium dodecylsulphate (SDS)/pentanol swollen lamellar phases, were considered. The temperature dependence of the 14N quadrupolar splitting was followed both in the case of oil (either n-dodecane or n-heptane) and brine (a 0.2-M NaBr water solution) swelling. In the former, it paralleled the temperature dependence of the splittings of the alkane deuteria and, in both cases, it was opposite to 23Na quadrupolar splittings. Owing to the higher N2 solubility in hydrocarbons, the 14N NMR spectra provide complementary information to that obtained by means of the quadrupolar nuclei of water and hydrophilic solutes.

Equi-Biaxial Fatigue of Elastomers: The Effect of Oil Swelling on Fatigue Life

Abstract The effect of oil swelling on the fatigue life of ethylene propylene diene monomer rubber (EPDM) has been studied under conditions of equi-biaxial cycling using dynamic bubble inflation. Specimens were subjected to varying degrees of swelling in reference mineral oils and fatigued at constant engineering stress amplitudes. The reference oils used for swelling the EPDM had known aniline points, allowing the rubber-oil compatibility to be determined. The inflation fluid for fatigue testing was selected with a solubility parameter that would produce a desired level of incompatibility with the test specimens, thereby limiting the amount of additional swelling during cycling. Wöhler (S-N) plots were generated for dry and swollen specimens and the changes in complex elastic modulus E* and dynamic stored energy were analyzed. Specimen fractures were analyzed using scanning electron microscopy. The fractures in the swollen samples show that the failure surfaces flowed more readily over each other than did those of the dryer specimens.

ELECTROSPUN OIL SORPTIVE FIBER BASED ON EPDM

The electrospun EPDM ultrafine fiber (EUF) was prepared for oil sorption application. Through microwave radiation, the unsaturated side-chain of EPDM formed a crosslinking tri-dimensional network structure, which greatly improved physical properties. Gel and sol of EUF were isolated by extraction with cyclohexane. Sol EUF can be reused as oil sorbent through microwave radiation again. Infrared (IR) spectra were used to study the structure of EUF both before and after crosslink. The morphology of EUF was investigated by scanning electron microscopy (SEM). The oil swelling process of the gel EUF was studied. Oil sorption properties were measured by method ASTM (F726-81) while swelling kinetics was evaluated by an experimental equation. Compared with the granular and bulk oil sorbents based on EPDM, the gel EUF showed a fast swelling property and better oil sorption ability.

A Genetic Algorithm-Based Model to Predict CO-Oil Physical Properties for Dead and Live Oil

Abstract A key parameter in a CO2 flooding process is the CO2 solubility as it contributes to oil viscosity reduction and oil swelling which together, in turn, enhance the oil mobility and oil relative permeability. Often CO2-oil solubility parameters are established through time-consuming experimental means or using models or correlations available in the literature. However, one must recognize that such models or correlations to predict CO2-oil physical properties are valid usually for certain data ranges or site-specific conditions. Furthermore, it is to be noted that there is no reliable model available to predict CO2-live oil physical properties, as most of the available correlations are developed based on dead oil data. In this study, a genetic algorithm (GA)-based technique has been used to develop more reliable correlations to predict CO2 solubility, oil swelling factor, CO2-oil density and CO2-oil viscosity for both dead and live oils. These correlations recognize not only all major parameters that affect each physical property, but also take into account the effects of CO2 liquefaction pressure and oil molecular weight (MW). These correlations have been successfully validated with published experimental data and compared against several widely used correlations. The GA-based correlations have yielded more accurate predictions with lower errors than other correlations tested. Furthermore, unlike these correlations, which are applicable to only limited data ranges and conditions, GA-based correlations can be applied over a wider range and conditions. Another important and useful aspect is that GA-based correlations can also be integrated into any reservoir simulator for CO2 flooding design and simulation. Introduction Knowledge of the physical and chemical interactions between CO2 and reservoir oil, other than for study of the prospective recovery, are very important for any CO2 flooding project. The major parameter that affects CO2 flooding is CO2 solubility in oil because it results in oil viscosity reduction and oil swelling increase which, in turn, enhances the oil mobility, the oil relative permeability and increases oil recovery efficiency. Therefore, a better understanding of this parameter is vital to any successful CO2 flooding project. The effects of CO2 on oil physical properties are determined by laboratory studies and available modelling or correlation packages. It is very expensive and time consuming to conduct a laboratory study, which covers a wider range of data. On the other hand, for the available correlation packages, they can only be used in certain situations. They are not applicable in many situations as they have many limitations in their application. Furthermore, most of the available packages are developed for dead oil and there is no reliable model to predict the effect of CO2 on live oil physical properties. The objective of this study was to develop a more reliable model to predict the effects of CO2 on crude oil properties (CO2 solubility in oil, oil-swelling factor and CO2-oil mixture density and viscosity) for both dead and live oils. The new genetic algorithm (GA)-based modelling technique used in this study is based on GA software developed in an earlier work(1).

The Effect of Epoxidized Natural Rubber (ENR-50) or Polyethylene Acrylic Acid (PEA) as Compatibilizer on Properties of Ethylene Vinyl Acetate (EVA)/Natural Rubber (SMR L) Blends

The effect of epoxidized natural rubber (ENR) or polyethylene acrylic acid (PEA) as a compatibilizer on properties of ethylene vinyl acetate (EVA)/natural rubber (SMR L) blends was studied. 5 wt.% of compatibilizer was employed in EVA/SMR L blend and the effect of compatibilizer on tensile properties, thermal properties, swelling resistance, and morphological properties were investigated. Blends were prepared by using a laboratory scale of internal mixer at 120°C with 50 rpm of rotor speed. Tensile properties, thermal properties, thermo-oxidative aging resistance, and oil swell resistance were determined according to related ASTM standards. The compatibility of EVA/SMR L blends with 5 wt.% of compatibilizer addition or without compatibilizing agent was compared. The EVA/SMR L blend with compatibilizer shows substantially improvement in tensile properties compared to the EVA/SMR L blend without compatibilizer. Compatibilization had reduced interfacial tension and domain size of ethylene vinyl acetate (EVA)/natural rubber (SMR L) blends.

Prediction of CO2 Solubility in Oil and the Effects on the Oil Physical Properties

CO2 solubility in oil is a key parameter in CO2 flooding process. It results in oil swelling, increased oil density, and decreased oil viscosity. Laboratory studies needed to cover a wider range of data, and are time consuming, costly, and may be not available or possible in many situations. On the other hand, although various models and correlations are useful in certain situations, they may are not be applicable in many situations. In this study, a new genetic algorithm- (GA)-based technique has been used to develop more reliable correlations to predict CO2 solubility, oil swelling factor (SF), CO2-oil density, and viscosity of CO2-oil mixtures. Based on the Darwinian theory, the GA technique mimics some of the natural process mechanisms. Furthermore, GA-based model correlations recognize all the major parameters that affect each physical property and also well address the effects of CO2 liquefaction pressure. Genetic algorithm-based correlations have been successfully validated with published experimental data. In addition, a comparison of these correlations has been made against widely used correlations in the literature. It has been noted that the GA-based correlations yield more accurate predictions with lower errors than all other correlations tested. Furthermore, unlike other correlations that are applicable to limited data ranges and conditions, GA-based correlations have been validated over a wider range of data.