Performance Evaluation of Hybrid Steam-Solvent Processes in A Post-CHOPS Reservoir with Consideration of Wormhole Network

In this paper, techniques have been developed to evaluate performance of steam, solvents, and hybrid steam-solvent processes in a post-CHOPS reservoir with consideration of wormhole network. With the experimentally determined properties of injected gases and reservoir fluids, history matching is accomplished for the reservoir geological model conditioned to the fluid and sand production profiles together with pressure. Meanwhile, the wormhole network is characterized with the pressure-gradient-based (PGB) sand failure criterion. Once the history matching is finished, the calibrated reservoir geological model can be employed to quantify the contributions of steam, solvents, and hybrid steam-solvent processes under various conditions. The results show that huff-n-puff processes have a very good performance on oil production and recovery when wormhole network is fully generated and propagated. Among all the solvent-based methods, a pure CO2 huff-n-puff process has been proven to be more efficient than flue gas, while the addition of alkane solvents is also beneficial to oil recovery compared with CO2 only method. Since the addition of C3H8 and n-C4H10 will significantly decrease the heavy oil viscosity and enhance the swelling factor, all hybrid steam-solvent injection achieves high oil recovery by taking the advantage of both hot steam and solvents injection.

Performance Evaluation of Hybrid Thermal-Solvent Injection in a Post-CHOPS Reservoir With Consideration of Wormhole Network

In this paper, techniques have been developed to evaluate performance of thermal, solvents, and hybrid thermal-solvent processes in a post-CHOPS reservoir with consideration of wormhole network. With the experimentally determined properties of injected gases and reservoir fluids, history matching is accomplished for the reservoir geological model conditioned to the fluid and sand production profiles together with pressure. Meanwhile, the wormhole network is characterized with the newly developed pressure-gradient-based (PGB) sand failure criterion. Once the history matching is completed, the calibrated reservoir geological model is then employed to evaluate performance of thermal, solvents, and hybrid thermal-solvent processes under various conditions. It is found that huff-n-puff processes have a very good performance on enhancing oil recovery when wormhole network is fully generated and propagated. Among all solvent-based methods, pure CO2 huff-n-puff process shows a better performance than flue gas, while the addition of alkane solvents leads to a higher oil recovery compared with CO2 only method. Since the addition of C3H8 and n-C4H10 will significantly decrease the heavy oil viscosity and enhance the swelling factor, all hybrid thermal-solvent injection achieves high oil recovery by taking the advantage of both hot steam and solvents injection.

Yield and Quality of Isabgol (Plantago ovata Forsk) as Influenced by Planting Geometry and Nutrient Levels under Eastern Dry Zone of Karnataka

The experiment was laid out in a Factorial Randomized Block Design with sixteen treatments and replicated three times. The result indicated that the spacing of 22.5cm recorded significantly maximum number of spikes (36.50), seed yield (1221 kg /ha), husk yield (305 kg/ha), swelling factor (13.70 cc /g) and protein content (11.91%) in the seeds. Among the different nutrient levels, maximum number of spikes (35.79), seed yield (904 kg /ha), husk yield (225 kg/ha), swelling factor (13.93 cc /g) and protein content (12.24 %) of seeds were obtained with the application of 75 % RDF (37.5:18.75:22.50 + 7.5 t FYM.) and the interaction of row spacing of 22.5 cm and 75% RDF recorded maximum yiled and quality parameters found non significant.

Spatial segregation of mixed-sized counterions in dendritic polyelectrolytes

Langevin dynamics simulations are utilized to study the structure of a dendritic polyelectrolyte embedded in two component mixtures comprised of conventional (small) and bulky counterions. We vary two parameters that trigger conformational properties of the dendrimer: the reduced Bjerrum length, $$\lambda _B^*$$ λ B ∗ , which controls the strength of electrostatic interactions and the number fraction of the bulky counterions, $$f_b$$ f b , which impacts on their steric repulsion. We find that the interplay between the electrostatic and the counterion excluded volume interactions affects the swelling behavior of the molecule. As compared to its neutral counterpart, for weak electrostatic couplings the charged dendrimer exists in swollen conformations whose size remains unaffected by $$f_b$$ f b . For intermediate couplings, the absorption of counterions into the pervaded volume of the dendrimer starts to influence its conformation. Here, the swelling factor exhibits a maximum which can be shifted by increasing $$f_b$$ f b . For strong electrostatic couplings the dendrimer deswells correspondingly to $$f_b$$ f b . In this regime a spatial separation of the counterions into core–shell microstructures is observed. The core of the dendrimer cage is preferentially occupied by the conventional ions, whereas its periphery contains the bulky counterions.

The Effect of Carbonyl and Hydroxyl Compounds on Swelling Factor, Interfacial Tension, and Viscosity in CO2 Injection: A Case Study on Aromatic Oils

A factor influencing the effectiveness of CO2 injection is miscibility. Besides the miscible injection, CO2 may also contribute to oil recovery improvement by immiscible injection through modifying several properties such as oil swelling, viscosity reduction, and the lowering of interfacial tension (IFT). Moreover, CO2 immiscible injection performance is also expected to be improved by adding some solvent. However, there are a lack of studies identifying the roles of solvent in assisting CO2 injection through observing those properties simultaneously. This paper explains the effects of CO2–carbonyl and CO2–hydroxyl compounds mixture injection on those properties, and also the minimum miscibility pressure (MMP) experimentally by using VIPS (refers to viscosity, interfacial tension, pressure–volume, and swelling) apparatus, which has a capability of measuring those properties simultaneously within a closed system. Higher swelling factor, lower viscosity, IFT and MMP are observed from a CO2–propanone/acetone mixture injection. The role of propanone and ethanol is more significant in Sample A1, which has higher molecular weight (MW) of C7+ and lower composition of C1–C4, than that in the other Sample A9. The solvents accelerate the ways in which CO2 dissolves and extracts oil, especially the extraction of the heavier component left in the swelling cell.

Characterization and Comparison of Alkali Extracted Starches from Selected Cereals and Tubers

Aims: Starch is used in the food industry to impart functional properties and to modify food texture and consistency. In this study starches isolated from six sources using an alkali extraction method were evaluated for physicochemical properties. Study Design: Complete randomized design. Place and Duration of Study: Department of Food Science and Technology, Faculty of Livestock, Fisheries, & Nutrition, Wayamba University of Sri Lanka, Makandura, Gonawila (NWP), Sri Lanka between April 2017 and August 2017. Methodology: Starches were isolated from white rice, foxtail millet, proso millet, cassava, sweet potato and all-purpose wheat flour. Proximate composition, mineral content, physical properties and microscopic characteristics were determined and they were compared. Results: The level of starch extracted was within the range of 27.5-64.1% on a dry basis. Extracted starched contains about 99% carbohydrate in DW and less than 1% non-carbohydrate fraction (protein, fat, fiber and ash and minerals). The amylose content followed the order: proso millet > wheat > foxtail millet > rice > sweet potato > cassava. There was considerable variation in swelling factor, solubility, gelatinization temperature among all starches. Both swelling power and solubility had a positive relationship with temperature and the swelling power (at 90°C) followed the order: corn > cassava > foxtail millet > wheat > proso millet > rice > sweet potato. The gelatinization temperature of starches ranged from 62°C to 76°C. Conclusion: The study would be helpful to better understand the chemical, physical and microscopic characteristics of these starches and the application of novel starches obtain from non-conventional sources which are foxtail millet, proso millet and sweet potato as a thickening agent and a substitute to other common starches in food.