Multi-effect Research Articles

Largest WAG Pilot in Giant Al-Shaheen Field Reveals Optimization Methods

This article, written by JPT Technology Editor Chris Carpenter, contains highlights of paper SPE 190343, “Challenges and Learnings From Operating the Largest Offshore WAG in the Giant Al-Shaheen Field and Ways To Optimize Future WAG Developments,” by M. Pal, S. Furqan Gilani, and G. Tarsauliya, North Oil Company, prepared for the 2018 SPE EOR Conference at Oil and Gas West Asia, Muscat, Oman, 26–28 March. The paper has not been peer reviewed. This paper discusses the operation of the largest offshore high-pressure water-alternating-gas (WAG) injection pilot using hydrocarbon (HC) gas, with a gas-injection capacity of approximately 100 MMscf/D, in the giant Al-Shaheen field offshore Qatar. The paper also analyzes the current HC-WAG pilot and optimizes future development scenarios for extending HC-WAG injection to the field scale. Al-Shaheen WAG Background As part of the field-development plan, a comprehensive enhanced oil recovery (EOR) screening study was performed that explored the range of available EOR techniques. On the basis of these studies, WAG injection was identified as one of the more-promising EOR options for the field. Additional studies performed in 2006 and 2007 indicated a large full-field potential for WAG in Al-Shaheen, with an estimated recovery of hundreds of millions of barrels over and above water-flood recovery. Data analysis and intensive simulation work, including both a history match and several forecast sensitivities, were conducted to understand and to estimate WAG potential on Al-Shaheen reservoirs. The Al-Shaheen WAG process is largely an immiscible process with some multi contact miscibility effects between injectors and producers. Overall, WAG has been a success in the field in terms of seeing incremental oil gains on several patterns. Although physically successful, the project had been challenging operationally. In spite of incremental gains, a number of operational challenges were encountered during the execution of the WAG pilot. These challenges mostly were related to WAG-cycle conversions and operational efficiency of gas-compression systems. WAG Recovery Optimization WAG will be a major part of the development of the mature-flank and heavy-oil areas of the field. The areas proposed for WAG are undersaturated with gas at reservoir conditions. Incremental recovery from WAG could be affected by thermodynamic effects caused by large variations in permeability, viscosity, and saturation pressure in the field along with several other variables described in the complete paper. To analyze the effect of these optimization parameters on incremental oil recovery from WAG, a sector model with varying static and dynamic properties was built (Fig. 1). The properties of the sector model were based on the history-matched model of the neighboring areas. The well spacing was 700 ft, which lies in the middle of the well-spacing ranges of the ongoing WAG pilot wells (500 to 1,000 ft). The WAG sector model was initialized with a range of fixed oil API gravities. Different thermodynamic effects of gas injection have been examined on the sector model. The model is also simulated for different WAG cycle lengths (1/1, 3/3, 6/6, and 12/12), ratios (1:2, 2:1, and 1:3), and slug sizes (1–30 years of WAG). The effects of choking production wells and changes in injection gas composition were also tested on the sector model.

Design and economic evaluation of solar-powered hybrid multi effect and reverse osmosis system for seawater desalination

Reducing the cost of fresh water has always been a major concern in the desalination industry. A solar powered hybrid multi-effect distillation and reverse osmosis desalination plant (MED + RO) has been designed and optimised from an economical point of view in a previous work by the same authors. In the present study, the possibility of coupling the desalination plant with a photovoltaic (PV) solar farm is investigated, with the aim of generating electricity at low cost and in a sustainable way. A detailed mathematical model for the PV system has been implemented from the literature. Interestingly, the model can predict the cost of the PV system in terms of capital cost and electricity cost per kWh considering the input data of solar irradiation, duration of daylight and technical specification of a real solar module. Consequently, the solar PV model has been combined with the desalination model, which enables to estimate the cost of fresh water per cubic meter. Data about four locations, namely Isola di Pantelleria (IT), Las Palmas (ES), Abu Dhabi (UAE), and Perth (AUS), have been used to economically test the feasibility of installing the proposed plant, and especially of the PV solar farm.

Multi- To Single-Joint or the Reverse Exercise Order Does Not Affect Pectoralis Major Workout Performance.

The purpose of this study was to examine the acute effects of multi- to single-joint or the reverse exercise order on repetition performance and perceived exertion for the pectoralis major. Fourteen trained men (24.05 ± 4.17 yrs, 78.85 ± 3.51 kg, 175.42 ± 4.01 cm) underwent two different training sequences (SEQ1 and SEQ2). In SEQ1, all subjects performed 5 sets for maximal repetitions, with a 2-min rest interval, of the bench press followed by the machine chest fly with 10 repetitions maximum load. In SEQ2, the same procedures were repeated, but with the reverse order. The t-test did not show any differences (p = 0.140) in total workout repetitions between SEQ1 (62.22 ± 11.00 repetitions) and SEQ2 (55.40 ± 8.51 repetitions). Conversely, the total repetition number for the bench press exercise was significantly greater (p = 0.001) following SEQ1 (34.36 ± 4.68 repetitions) compared to SEQ2 (25.85 ± 6.73 repetitions). In contrast, the total repetition number for the machine chest fly exercise following SEQ2 was significantly greater (p = 0.001) (33.50 + 4.11 repetitions) compared to SEQ1 (27.85 ± 6.52 repetitions). Despite no significant differences found for the rating of perceived exertion (RPE) values between SEQ1 and SEQ2 for the barbell bench press in all sets (p ≥ 0.083), significantly higher RPE values for the machine chest fly were observed over the first three sets following SEQ1 compared to SEQ2 (p < 0.01). In conclusion, the total workout repetitions were not significantly different when performing the traditional multi- to single-joint or the reverse exercise order when training the pectoralis major muscle.

Techno-economic evaluation of a multi effect distillation system driven by low-temperature waste heat from exhaust flue gases

In this study, technical and economical evaluation of a multi effect distillation (MED) system is presented which utilizes the vapor produced from waste heat of exhaust flue gases. In order to recover the waste heat of flue gases, a shell and tube heat exchanger was designed with the Polytetrafluoroethylene (PTFE) material in order to resist corrosion as a result of sulfuric acid formation. Recoverable energy, which is obtained from experimental data, serves as the source of energy required to produce water vapor. Due to high fluctuations in the amount of vapor produced, an auxiliary boiler is employed for its compensation. The vapor which has been produced by the heat exchanger and/or auxiliary boiler, is used as the motive steam in the MED distillation. Economic analysis of MED distillation system driven by low-temperature waste heat is carried out and system payback period based on natural gas saving is obtained. Finally, waste-heat-driven MED distillation system is compared to a conventional MED on the basis of the levelized cost of water (LCOW) at different electrical and natural gas tariffs as well as the real interest rates. Economic evaluation shows that the LCOW is about 1.13–2.9 $/m3.

Landfill leachate and industrial effluent treatment using advanced evaporation technology

Evaporation is one of the most efficient methods for separation of dissolved solids and water. Using evaporation, high quality, recyclable or dischargeable water can be produced. An advanced evaporation technology for industrial effluent and landfill leachate treatment has been developed. Construction material of the evaporative heat transfer surface is the key difference to conventional systems: thin, corrosion resistant and elastic polymeric film is used instead of rigid metals. The cost of the polymeric surface is low, decreasing the high costs that are associated with conventional evaporators. Thus, evaporation is now a feasible alternative in a number of effluent treatment applications. The technology applies Mechanical Vapor Recompression (MVR) concept using electrical energy or Multi-Effect (ME) concept utilizing waste heat as energy source. In both concepts the evaporative surface areas are larger than in conventional systems. As a result of the large surface electrical energy consumption is low in the MVR-type evaporators, typically 8-12 kWh/m3 of recovered water; in ME-type evaporators the large area enables the utilization of low value waste heat in an efficient way.

A hierarchical modelling approach to assess multi pollutant effects in time-series studies.

When assessing the short-term effect of air pollution on health outcomes, it is common practice to consider one pollutant at a time, due to their high correlation. Multi pollutant methods have been recently proposed, mainly consisting of collapsing the different pollutants into air quality indexes or clustering the pollutants and then evaluating the effect of each cluster on the health outcome. A major drawback of such approaches is that it is not possible to evaluate the health impact of each pollutant. In this paper we propose the use of the Bayesian hierarchical framework to deal with multi pollutant concentrations in a two-component model: a pollutant model is specified to estimate the ‘true’ concentration values for each pollutant and then such concentration is linked to the health outcomes in a time-series perspective. Through a simulation study we evaluate the model performance and we apply the modelling framework to investigate the effect of six pollutants on cardiovascular mortality in Greater London in 2011-2012.

Effects of multi- Deposition on the structural and optical properties of CdS nanocrystalline thin film prepared by CBD technique.

Cadmium sulfide (CdS) nanocrystalline thin films have been prepared by chemical bath deposition (CBD) technique on commercial glass substrates at 70ºC temperature. Cadmium chloride (CdCl2) as a source of cadmium (Cd), thiourea (CS(NH2)2) as a source of sulfur and ammonia solution (NH4OH) were added to maintain the pH value of the solution at 10. The characterization of thin films was carried out through the structural and optical properties by X-ray diffraction (XRD) and UV-VIS spectroscopy. A UV-VIS optical spectroscopy study was carried out to determine the band gap of the nanocrystalline CdS thin film and it showed a blue shift with respect to the bulk value (from 3.9 - 2.4eV). In present work effects of thickness on the structural and optical properties of CdS nanocrystalline thin films were discussed.

Effects of plasma glucose levels on regional cerebral 18F-fluorodeoxyglucose uptake: Implications for dementia evaluation with brain PET imaging

PurposeHyperglycemia affects FDG uptake in the brain, potentially emulating Alzheimer’s disease in normal individuals. This study investigates global and regional cerebral FDG uptake as a function of plasma glucose in a cohort of patients. Methods120 consecutive male patients with FDG PET/CT for initial oncologic staging (July–Dec 2015) were reviewed. Patients with dementia, cerebrovascular accident, structural brain lesion, prior oncology treatment or high metabolic tumor burden (recently shown affecting brain FDG uptake) were excluded. 53 (24 nondiabetic) eligible patients (age 65.7 ± 2.8 mean ± SE) were analyzed with parametric computer software, MIMneuro™. Regional Z-scores were evaluated as a function of plasma glucose and age using multi variable linear mixed effects models with false discovery analysis adjusting for multiple comparisons. If the regression slope was significantly (p < 0.05) different than zero, hyperglycemia effect was present. ResultsThere was a negative inverse relationship (p < 0.001) between global brain FDG uptake and hyperglycemia. No regional hyperglycemia effect on uptake were present when subjects were normalized using pons or cerebellum. However, regional hyperglycemia effects were seen (p < 0.047–0.001) when normalizing by the whole brain. No obvious pattern was seen in the regions affected. Age had a significant effect using whole brain normalization (p < 0.04–0.01). ConclusionsCortical variation in FDG uptake were identified when subjects were hyperglycemic. However, these variations didn’t fit a particular pattern of dementia and the severity of the affect is not likely to alter clinical interpretation.

Cost evaluation and optimisation of hybrid multi effect distillation and reverse osmosis system for seawater desalination

In this research, the effect of operating parameters on the fresh water production cost of hybrid Multi Effect Distillation (MED) and Reverse Osmosis (RO) system is investigated. To achieve this, an earlier comprehensive model developed by the authors for MED + RO system is combined with two full-scale cost models of MED and RO processes collected from the literature. Using the economic model, the variation of the overall fresh water cost with respect to some operating conditions, namely steam temperature and steam flow rate for the MED process and inlet pressure and flow rate for the RO process, is accurately investigated. Then, the hybrid process model is incorporated into a single-objective non-linear optimisation framework to minimise the fresh water cost by finding the optimal values of the above operating conditions. The optimisation results confirm the economic feasibility of the proposed hybrid seawater desalination plant.

Effects of multi−walled carbon nanotubes on pyrene adsorption and desorption in soils: The role of soil constituents

Once entering soil, carbon nanotubes (CNTs) can influence the fate of hydrophobic organic compounds (HOCs) in soil due to its strong adsorption capacity. This process may be influenced by the interactions between CNTs and soil constituents. The mechanisms therein were investigated in the present study by examining pyrene adsorption/desorption on one CNTs, two soils (black soil and paddy soil), and mixtures thereof. CNTs' amendment enhanced soil site heterogeneity and adsorption capacity of pyrene while it was less than that predicted by the sum of the individual adsorption on soils and CNTs, which was more obvious at low aqueous concentrations. This could be due to the interactions between soil constituents (dissolved organic matter (DOM) and clays) and CNTs. Modification of CNTs by DOM attenuated pyrene adsorption by 14.9%–66.1%, which was ascribed to occupying of surface adsorption sites, pore blockage of CNTs' aggregates, enhancement of surface polarity, and enhancement of pyrene solubility in aqueous phase. The coexistence of clay (kaolinite) also showed inhibition on pyrene adsorption onto CNTs with a reduction of 19.2%−40.2%. This could be ascribed to that the attachment of clay particles on CNTs' aggregates could cover the surface adsorption sites and enhance the surface polarity of CNTs. The effect of CNTs amendment on pyrene desorption hysteresis differed among soils. The hysteresis index of the black soil doubled after CNTs' amendment while that of paddy soil remained unchanged. The results of this study provide insights into the possible effects of CNTs on the fate of HOCs in real soil environment.

Reverse electrodialysis – Multi effect distillation heat engine fed by lithium chloride solutions

Reverse electrodialysis – Multi effect distillation heat engine fed by lithium chloride solutions

An investigation into the photothermal effects of multi- functional gold coated Fe3O4 Nanoparticles in the presence of external magnetic field and NIR laser irradiation on model of melanoma cancer cell line B16F10 in C57BL/6 mice

Introduction: Photothermal therapy using gold nanoshells is one of cancer therapy methods. Gold nanoshells generally consist of a silica core and a thin gold shell. Fe3O4@Au core-shell can be used for magnetic targeted therapy. The objective of this study was investigation of the photothermal effects of magnetically targeted Fe3O4@Au NPs and NIR laser irradiation on model of melanoma cancer. The effective parameters in photothermal therapy include nanoparticles concentration, laser power density, and laser exposure time. In this research the effects of these parameters on produced heat and its spatial distribution in tissue equivalent phantom during photothermal therapy was evaluated. Materials and Methods: At the first, the thermal distribution in tissue equivalent phantom have been simulated. The optimum laser power density and exposure time determined and simulation result verified in tissue equivalent phantom using thermocouple thermometer model ST 8891E. Invivo studies was performed on 100 C57BL/6 mice. Fe3O4@Au NPs was injected veinously to tumor inoculated mice, and accumulated in tumor using an external magnet. Then the tumor region was irradiated by laser (808 nm, 2.5 W/cm2, 6 minutes). For evaluation of treatment efficiency, we used pathologic studies and tumor growth measurement. Moreover, the temperature of tumor region was measured using IR camera model 875-1i. Results: Simulation predicted a maximum temperature elevation of 12.5 oC for nanoparticles concentration of 7 × 109 NP/ml and laser power density of 3.5 W/cm2 and irradiation time 6 min. The maximum discrepancy between simulations and phantom measurements was 8.6%. on the basis of simulation results the optimum parameters for treatment was nanoparticles dose 1.5 mg/kg, laser power density 3.5 W/cm2 and irradiation time 6 min. 2 weeks after treatment the average tumor volume multiplication in control relative to treatment group, was 10 and this was significant (one-way ANOVA, p < 0/001). The difference in average percentages of necrosis in control and treatment group was significant too (Mann-Whitney, p = 0.029). Conclusion: In this study melanoma tumor inoculated in mice was treated using magnetically targeted Fe3O4@Au nanoparticles (dose of 1.5 mg/kg) and laser exposure (power density = 2.5 W/cm2 and exposure time 6 min). The results showed that simulation can be a reliable technique for photothermal therapy treatment planning.

Inharmonic Spectra with a Rock Guitar Effects Pedal

Students in introductory physics courses encounter harmonics when they study standing waves on strings and in pipes. The Fourier spectrum, which plots amplitude against harmonic number, can describe all periodic tones imaginable. However, most sounds are aperiodic and therefore have additional spectral components. A real-world application that includes frequencies outside the harmonic series can be found in guitar pedal effects used by rock musicians. A four-minute video accompanying this paper includes the exotic sound of guitar playing when the guitar pedal adds inharmonic frequency components. The principle underlying the pedal effects discussed in this paper is balanced modulation. Some inharmonic spectra based on balanced modulation can easily be sketched after students have learned about timbre and Fourier spectra.

Performance analysis of hybrid system of multi effect distillation and reverse osmosis for seawater desalination via modelling and simulation

The coupling of thermal (multi stage flash, MSF) and membrane processes (reverse osmosis, RO) in desalination systems has been widely presented in the literature to achieve an improvement of performance compared to an individual process. However, very little study has been made to the combined multi effect distillation (MED) and reverse osmosis (RO) processes. Therefore, this research investigates several design options of MED with thermal vapor compression (MED_TVC) coupled with RO system. To achieve this aim, detailed mathematical models for the two processes are developed, which are independently validated against the literature. Then, the integrated model is used to investigate the performance of several configurations of the MED_TVC and RO processes in the hybrid system. The performance indicators include the fresh water productivity, energy consumption, fresh water purity, and recovery ratio. Basically, the sensitivity analysis for each configuration is conducted with respect to seawater conditions and steam supply variation. Most importantly, placing the RO membrane process upstream in the hybrid system generates the overall best configuration in terms of the quantity and quality of fresh water produced. This is attributed to acquiring the best recovery ratio and lower energy consumption over a wide range of seawater salinity.

An efficient integrated trigeneration system for the production of dual temperature cooling and fresh water: Thermoeconomic analysis and optimization

This paper describes and analyzes an integrated trigeneration system for the production of air conditioning, fresh water and refrigeration at different temperatures. A single effect steam driven H2O-LiBr absorption cooling (ABC) cycle is integrated with a multi effect distillation (MED) unit and a CO2 based parallel compression economization-vapor compression refrigeration (PCE-VCR) cycle. The thermo-economic analysis is performed to identify how the integration can improve the energy utilization and annual costs. A detailed parametric study of several key design and operating parameters and an economic optimization are also conducted. The analysis shows that the MED plant can produce a significant amount of fresh water using the free steam supplied by the ABC cycle. Changes in the number of effects, top and last effect brine temperatures, size of the VCR cycle and number of operating hours significantly impact the MED plant productivity and unit production cost of water (UPCW). The integrated ABC-MED-VCR system, in a base case analysis, reduces the unit production cost of cooling (UPCC) for combined cooling and refrigeration and the UPCW by 25% and 27%, respectively compared to separate use of the three systems. Due to integration, substantial improvements in the fuel energy utilization and reductions in the annual capital cost (ACC) and annual operating cost (AOC) are achieved. Also, the AOC and ACC decrease 38% and 13%, respectively. At the optimized conditions, utilization of exhaust waste gas to drive the integrated ABC-MED-VCR system leads to additional 52%, 41% and 0.13% reductions in the AOC, UPCC and UPCW, respectively.

Microstructure evolution and corrosion resistance of multi interfaces Al-TiAlN nanocomposite films on AZ91D magnesium alloy

Multi interfaces Al-TiAlN nanocomposite films were deposited on AZ91D magnesium alloy with ion source hybrid magnetron sputtering. Relationship between microstructure evolution and corrosion resistance of the films was investigated. The results show that the column structure is interrupted by multi interfaces. The nanocomposite films are consisted of nanocrystal TiN and amorphous AlN phase. The highest hardness of 31.3 GPa and lowest corrosion current density of 9.37 × 10−8 A/cm2 can be obtained by tuning the interface period. The deflection effect of multi interfaces is the key for the improved corrosion resistance, and the failure mechanism is related to pitting and filiform corrosion.

Modeling and multi-objective optimization of a novel biomass feed polygeneration system integrated with multi effect desalination unit

This paper mainly focuses on the design and optimization of a novel integrated system to meet fresh water, electricity, and hot water demands. A novel combination of different system is used to generate multi products. The exergy and economic analyses are combined to carry out a parametric study to find the impact of main decision variables on a polygeneration system. The exergy analysis reveals that combustion chamber and gasifier have the highest exergy destruction rates with 84% of the system total exergy destruction rate. In addition, the system exergy efficiency shows that in the initial state, the exergy efficiency of polygeneration system is 27.9%. Results show that an increment in the gasification temperature from 950 K to 1150 K leads to fresh water flow rate increases from 1060 m3/day to 1160 m3/day. The parametric study of the system reveals that the defined objective functions are highly depends on the changes in the nine decision variables. Using a genetic algorithm optimization method, the optimum design values are obtained. The results of multi-objective optimization show that within reasonable changes for decision variables, the system exergy efficiency can change between 20% and to 42%, and the system total cost rate can vary from 100 $/h to 600 $/h.

Effects of multi and selective targeted tyrosine kinase inhibitors on function and signaling of different bladder cancer cells

BackgroundSignaling of receptor tyrosine kinases (RTK) is dysregulated in various malignancies including bladder cancer. RTKs trigger pro-proliferative, anti-apoptotic and metastatic signaling pathways. Here, we assessed the effects of a selective tyrosine kinase inhibitor (TKI) (BGJ398) targeting fibroblast growth factor receptor (FGFR) and a pan-TKI (TKI258) targeting (FGFR), platelet derived growth factor receptor (PDGFR) and vascular endothelial growth factor receptor (VEGFR) in bladder cancer cells. MethodsLevels of mRNA transcripts were measured in nine human cell lines by quantitative RT-PCR. Cell function was assessed for viability, colony formation, migration, apoptosis and proliferation. Protein mediators of signal transduction were measured by Western-blot. ResultsmRNA transcripts encoding RTK-related components, transcription factors, epithelial and mesenchymal transition (EMT) markers as well as cell cycle and apoptotic factors were determined in the cell lines. Principal component analysis ordered one epithelial-like cell cluster (5637, BFTC-905, MGHU4, RT112) and one mesenchymal-like cell cluster (T24, UMUC3, HU456, TCC-SUP). Cell response scores towards TKI258 and BGJ398 treatment were heterogeneous between cell lines and correlated with certain transcript levels. Analysis of signal transduction pathways revealed inhibition of fibroblast growth factor receptor (FGFR) signaling and induction of cell cycle dependent kinase (CDKN1A, p21) in epithelial-like cells differing in this regard from responses to mesenchymal-like cells that exhibited inhibition of mitogen-activated protein kinase (MAPK). ConclusionRTK and EMT related transcript analysis separate bladder cancer cells in two clusters. Functional responses towards TKI258 and BGJ398 treatment of bladder Fcancer cells were heterogeneous with deviating effects on signaling and possibly different therapeutic outcome.

A Finite Horizon Markov Decision Process Based Reinforcement Learning Control of a Rapid Thermal Processing system

Manufacture of ultra large-scale integrated circuits involves accurate control of a challenging nonlinear Rapid Thermal Processing (RTP) system. Precise control of temperature profile and rapid ramp-up and ramp-down rates demanded by a RTP system cannot be achieved with conventional control strategies due to nonlinear and multi time-scale effects. In this paper the control of a RTP system is reformulated as an optimal multi-step sequential decision problem using the framework of finite horizon Markov decision processes and solved using a Reinforcement Learning (RL) algorithm. Three increasingly complex RL based control strategies are explored and compared with the existing state-of-the-art approach for controlling RTPs. Simulation results indicate that the approach proposed in this paper achieves superior control of the temperature profile and ramp-up and ramp-down rates for the RTP system.

A NUMERICAL MODEL ON GEOSYNTHETIC REINFORCED PILE SUPPORTED EMBANKMENTS

Reinforced pile embankments are started use more commonly because they allow fast construction of highways. When geosynthetics are adopted to piled fills, this kind of structures are then called as geosynthetic reinforced piled structures. When the geosynthetics are used, area of pile caps is reduced because geosynthetic transfers fill load to piles by its membrane effect. In this study, effect of multi – layer reinforcement is investigated using 2D finite element method. For this purpose, settlements, pressures, excess pore water and horizontal displacements are analyzed. Results showed that using two and three layers of reinforcement significantly decreases settlements on foundation soil and embankment surface. Placement of additional layer has great effect on settlements, pressures, excess pore water pressure and horizontal displacements. It is also found out that, two layers of reinforcement is more effective when only settlements are considered.