bluuebunny/crossref_metadata_2025_split huggingface dataset:
A New Screening Model for Gas and Water Based EOR Processes
Authors: Bang Vishal 
Published: July 2013

AbstractScreening for Enhanced Oil Recovery (EOR) processes is a critical step in evaluating future development strategies for depleted reservoirs under primary and secondary recovery. However, selecting the optimum EOR process for a given reservoir is challenging because it requires evaluating and comparing performance for various EOR processes, which is complex and time consuming.This paper presents a new EOR screening model that can predict the performance of various gas- and water-based EOR processes based on simple reservoir properties. The model estimates the oil recovery from miscible and immiscible gas/solvent injection (CO2, N2, and hydrocarbons), low salinity water flood, polymer, surfactant-polymer, alkaline-polymer and alkaline-surfactant-polymer floods. The screening model is based on a set of correlations that were developed using the response surface methodology, which correlates the oil recovery at dimensionless times to the important reservoir and fluid properties and EOR process variables identified for each process. The results of the model have been validated against a number of field test and numerical simulation results.The screening model provides the capability to screen a large set of reservoirs for a wide spectrum of EOR processes, to identify the good EOR targets and the optimum EOR process for the target reservoirs. In addition, this model easily performs sensitivity analysis without the need for numerical simulations, allowing teams to account for uncertainty in reservoir properties and optimization of flood design. Finally, the methodology can be applied for developing screening models for other oil recovery mechanisms such as thermal (steam injection, SAGD), microbial EOR and other methods.
A New Paradigm for History-Matching Saturation Logs to Quantify EOR Targets
Authors: Wei Lingli 
Published: July 2013

AbstractPrior to any EOR application, quantifying the remaining oil saturation (ROS) after water flood is critical in order to establish the target oil for a potential EOR scheme. The most widely available datasets for quantifying ROS are from the saturation logs such as resistivity logs from infill wells and pulsed neutron capture (PNC) logs from cased wells. However, the interpretation of these logs generally requires prior knowledge of water salinity. In most water flood projects, the injected water is different from the formation water, and the salinity is unknown in the water flooded zones. Logging tools for saturations without prior knowledge of salinity, such as the C/O log, also have limitations.The current practice to overcome this problem is to apply one or more of the following techniques:• Log-injection-log• Chemical tracer• Sponge coring, pressurized coring, etc.However, these techniques are relatively expensive and time-consuming. They cannot be used routinely field wide as a reservoir surveillance tool.In this paper, we present a methodology to reduce the uncertainties in saturation logs within the context of reservoir model history-matching. In addition to matching pressure and water cut, the new methodology seeks to match the produced water chemistry too (with formation water and injection water chemistry as inputs). This is due to the recent advance of reservoir simulations that can model reservoir water composition changes by considering geochemical reactions of injection waters, formation brine, and reservoir minerals. With this new simulation capability, resistivity and sigma values per grid block are computed as part of the simulation, thus pseudo-logs of total resistivity and neutron capture cross section (S) can be generated as part of the simulation. This enables direct history-matching of the measured log signals.For an EOR project, the implication of this new simulation methodology is to encourage the frequent sampling and analysis of injection and produced water as part of the reservoir surveillance, and run resistivity and/or S logs to monitor saturation changes even when injection water is significantly different from formation water.
Miscible Water Alternating Gas in Black Oil and Near-Critical Reservoirs with Gravity and Thermal Compositional Gradients
Authors: Hendraningrat Luky 
Published: July 2013

Abstract
The paper presents compositional simulation studies of miscible water-alternating-gas (WAG) flooding in stratified reservoirs with respect to compositional variation with vertical depth and temperature. Two series of fluid system were selected from fifth and third SPE comparative study for Reservoir-A and Reservoir-B respectively. The Reservoir-A is an undersaturated black oil reservoir and has initial gas-oil ratio (GOR) of 557 scf/stb. Meanwhile Reservoir-B is near-critical oil reservoir with initial GOR of 3519 scf/stb. The minimum miscible pressure (MMP) variation with depth was calculated using equation of state in both reservoirs. In this study, temperature gradient sensitivity is ranging from 10 to 30°F per 1000 ft for both active and passive thermal gradient.
The existence of thermal diffusion in WAG process is also discussed. It is investigated that active and passive thermal gradient will give opposite composition variation trend. In active temperature gradient, the amount of light components will increase and heavy components will opposite with respect to depth. Unlike active thermal gradient, the gravity isothermal and passive thermal gradients segregate the heavy components toward the bottom.
The initial oil in place (IOIP) varies due to compositional variation which is again due to gravity and thermal gradients. These issues should be even more obvious when we have oil reservoir with higher GOR or near-critical reservoir. In these particular reservoirs, the presence of gravity and passive thermal gradients will decrease IOIP calculation whereas both reservoirs will have less C7+ components than in basecase. Otherwise, considering thermal diffusion effect by applying active thermal gradients will increase IOIP.
Several parameters were also evaluated during WAG process in both reservoirs such as: various hydrocarbon injection gases, cyclic injection scheme, WAG cycle and ratio, and reservoir heterogeneities. Therefore the effect of compositional variation due to gravity and thermal gradients can be conclusively evaluated.
Chemical EOR Evaluation for GNPOC and PDOC Fields in Sudan
Authors: Qiang Wang , Ming Gao , Zhaoxia Liu , Bakar Mohamad Abu , Chong Yeap Yeow , Adnan Izwan B. 
Published: July 2013

Abstract
The objective of this paper is to scope the Chemical EOR potential in both GNPOC and PDOC fields in Sudan. From the initial EOR screening, the most amenable EOR processes identified for both GNPOC and PDOC are mainly chemical and thermal EOR. Chemical EOR is the leading EOR process in GNPOC fields while thermal EOR is the leading EOR process in PDOC fields.
Chemical EOR evaluation was performed using Eclipse EOR black oil simulator. Simulations were performed on sector models constructed or extracted from full field models which have been conditioned to the current reservoir condition. The chemical input data was referenced mainly from Qing Hai oil field lab data which oil properties are similar to that of Sudan's. The chemical EOR evaluation encompass 3 different types of chemical processes; polymer flooding, surfactant-polymer (SP) flooding and alkaline-surfactant-polymer (ASP) flooding. Chemical EOR can potentially improve field recovery factor between 4-18% depending on the type of chemical EOR process. ASP flooding possess the highest potential with incremental oil recovery over waterflood ranging between 12%-18% followed by SP flooding and polymer flooding. ASP flooding is taken as the reference chemical process in this study as it as it represent the highest chemical potential.
The outcome of this study is believe to be helpful to successful planning of Chemical EOR applications in sudan.
Performance Review of Polymer Flooding in a Major Brown Oil Field of Sultanate of Oman
Authors: Thakuria Chandan , Al-Amri Mohsin Saud , Al-Saqri Kawthar Ahmed , Jaspers Henri F , Al-Hashmi Khalid Hamad , Zuhaimi Khalid 
Published: July 2013

Abstract
The first field scale Polymer flood project in the Middle East region is being implemented in an oil field of Sultanate of Oman from early 2010. The oil field discussed here containing viscous oil (90 cp) was discovered in 1956 and is located in eastern part of South Oman Salt basin. First commercial production started in 1980 from this field. The field has gone through different development phases in its 30 years of history prior starting tertiary recovery phase by polymer flooding.
This field scales Polymer flood project comprising 27 patterns as Phase-1 covers about one third of the total field IOIP (initial oil in place). It is worth mentioning that whole field is under water flooding and water injection was going on prior to initiation of Polymer flood in all these 27 injectors. Further extension in phases to full field polymer flooding is under evaluation.
Till now this Polymer flood project has successfully completed 3 years of good performance contributing to significant oil gain. This paper describes briefly about the principles involved in polymer flooding, planning of this polymer flood project, field implementation and field examples of polymer response. In addition, a few practical aspects of managing key issues in polymer flooding like- fracture growth in injectors, shear degradation of polymer solution, pattern conformance and back produced polymer has been covered in this paper.
Electrostatic Dehydration of Heavy Oil from Polymer Flood with Partially Hydrolyzed Polyacrylamide
Authors: Zheng Frank , Quiroga Pilar , Zaouk Moshen , Blackman Nick , Mandewalkar Pavan , Sams Gary W. , Sellman Erik , Gopeesingh Cameron Horace , Morgan Justin 
Published: July 2013

Abstract
Polymer flood using partially hydrolyzed polyacrylamide (HPAM) has been proven to be an effective method to increase oil recovery. However, when HPAM breaks through the reservoir and shows up in the produced fluids, it brings unique emulsion characteristics and challenges to the separation processes. Operators have experienced frequent equipment failures on heat exchangers and heating elements. Traditional oil dehydration uses mechanical heater treaters which rely on elevated temperature to improve the settling of the dispersed water phase. In HPAM flood, the fire tubes in these mechanical heater treaters have become problematic and experienced repetitive failures. Electrostatic technology uses the response to the electrostatic field by the polar dispersed water phase to enhance the water settling. Electrostatic technology has been a proven technology for oil dehydration and desalting for water flood and other recovery methods such as Steam Assisted Gravity Drainage (SAGD), but not widely used in HPAM flood. A joint study was conducted between Cameron and Cenovus to evaluate the electrostatic dehydration of the heavy oil from HPAM flood. The results of the study indicate that, due to the presence of HPAM in water, the electrostatic dehydration of the wet oil from HPAM flood demonstrates some unique characteristics. Electrostatic dehydrators can achieve about 300% of the capacity of mechanical heater treaters. Proper equipment and process designs are important to reduce the equipment failures. The results of the study offer a more effective oil dehydration technology to the HPAM flood producers. The benefits of electrostatic dehydration can be especially valuable for the offshore implementation of HPAM flood due to the space and weight savings.
Foam assisted CO2-EOR; Concepts, Challenges and Applications
Authors: Talebian Seyedeh H. , Masoudi Rahim , Tan Isa M. , Zitha Pacelli L. 
Published: July 2013

AbstractFoam assisted CO2 enhanced oil recovery has attracted increasing attention of oil companies (operators and service companies) and research institutions mainly due to the potentially high benefit of foam on CO2-EOR.Miscible and immiscible CO2 flooding projects are respectively proven and potential EOR methods. Both methods have suffered from limited efficiency due to gravity segregation, gas override, viscous fingering and channeling through high permeability streaks. Numerous theoretical and experimental studies as well as field applications have indicated that foaming of CO2 reduces its mobility, thereby helping to control the above negative effects. However, there are still various conceptual and operational challenges, which may compromise the success and application of foam assisted CO2-EOR.This paper presents a critical survey of the foam assisted CO2-EOR process to reveal its strengths, highlight knowledge gaps and suggest ways. The oil recovery mechanisms involved in CO2 foam flood, the effect of gaseous and soluble CO2 on the process, synergic effect of foaming agent and ultra-low IFT surfactants, logistic and operational concerns, etc. were identified as among the main challenges for this process. Moreover, the complex flow behaviour of CO2, oil, micro-emulsion and brine system dictates a detailed study of the physical-chemical aspects of CO2 foam flow for a successful design. Unavailability of reliable predictive tools due to the less understood concepts and phenomena adds more challenges to the process results and application justifications.The study highlights the recent achievements and analysis about foam application and different parameters, which cannot be avoided for a successful foam assisted CO2 flood design and implementation. Accordingly, the study also addresses prospects and suggests necessary guidelines to be considered for the success of CO2 foam projects.
Experimental and Numerical Investigation of the Impact of Design Parameters on the Performance of WAG and SWAG Injection in Water-Wet and Mixed-Wet Systems
Authors: Fatemi S. Mobeen , Sohrabi Mehran 
Published: July 2013

Abstract
Experiments involving three-phase flow in porous media including Water-Alternating-Gas (WAG) injection are time-consuming andexpensive. Therefore, it is not feasible to experimentally consider all alternative injection schemes of these processes for different wettability and IFT (interfacial tension) conditions. The standard approach is to perform numerical simulations using models preferably tuned by laboratory data and experiments.
We present the results of a series of two-phase (WF and GF) and three-phase (WAG and SWAG) coreflood experiments performed in both water-wet and mixed-wet rocks. The objective of the experiments was to understand the impact of wettability and injection strategy, as well as generating reliable data for tuning a simulation model. A numerical model was developed and validated via experimental results under both wettability conditions, and then used to investigate the effect of a large number of parameters including; WAG starting time and slugsizes well as oil/gas IFT and wettability on the performance of different injection scenarios.
The results show that for water-wet systems, the highest oil recovery is achieved by SWAG (Simultaneous Water and Gas) and WAG injections and the poorest injection scheme is primary WF (water flood), whereas in the mixed-wet system, WAG and SWAG are the best and worst injection scenarios, respectively. In water-wet systems, the SWAG performance improved by increasing the ratio of gas to water while in mixed-wet systems, SWAG performance decreased by increasing gas to water ratio. Under water-wet conditions, better performance was achieved by smaller WAG slug sizes (higher number of WAG cycles) but for mixed-wet systems WAG performance decreased with increasing the number of the cycles. Our results also show that under near-miscible oil/gasconditions (IFT = 0.04 mN.m-1), the oil recovery by primary GF (Gas Flood) was much higher for water-wet systems compared to the mixed-wet conditions. Although the same trend has been observed for the immiscible condition (IFT = 9.4 mN.m-1), but under immiscible conditions the difference between the performance of GF for the two wettabilities(water-wet and mixed-wet) is not significant.For all oil/gas IFT values tested, WAG performance was found to be higher in mixed-wet systems compared to their water-wet counterparts, however, the effect of wettability was more pronounced in higher gas/oil IFT conditions. For both wettability conditions, starting WAG before water breakthrough of theprimary WF increased oil recovery.
Supercritical CO2-Foam - The Importance of CO2 Density on Foams Performance
Authors: Solbakken J. S. , Skauge A.. , Aarra M. G. 
Published: July 2013

Abstract
In CO2 projects for enhanced oil recovery (EOR) a critical factor is possible early CO2 breakthrough and consequently poor sweep efficiency. Injection of foam can block and divert CO2 which may improve sweep efficiency.
Large changes in physical properties of CO2 with temperature and pressure might affect CO2-foam performance under various reservoir conditions. Recently, we have focused on understanding supercritical CO2-foam properties and this paper describes the importance of supercritical CO2 density on CO2-foam performance in outcrop Berea sandstone core material.
Foam flooding experiments were conducted in sandstone core material at different pressures from 30 to 280 bar and at temperatures of 50 and 90&deg;C using an AOSC14/16 surfactant. Results showed high foam strengths at low CO2 density. In fact, the strongest supercritical CO2-foam was generated at the lowest supercritical CO2 density tested, quite comparable to foam strength obtained with gaseous CO2. Only reduced foam strengths were found with dense supercritical CO2 (MRF 3-11).
Foam generation was studied with both equilibrated and non-equilibrated fluids. Previously, we showed that CO2-foam stability and blocking ability were strongly reduced when mass transfer occured. In this study delay in foam strength build-up was observed with non-equilibrated fluids. In addition, visual observations of the foam texture indicated larger bubbles.
Compared to N2-foams at similar conditions CO2-foams were weaker and showed coarser foam structure.
Systematic Investigation of Formulation for Chemical EOR: Back to Basics Production Chemistry Approach
Authors: Shepherd A. G. , Faber M. J. , Bouwmeester R. C. 
Published: July 2013

Abstract
This paper discusses a structured combination of procedures used to investigate polymers for EOR application with the focus on performance, compatibility with production chemicals and phase behaviour. This approach allows for early identification of risks and points to further work necessary for mitigation before field implementation. The case studied here was a system with total dissolved solids (TDS) of 80000 mg/l and temperature requirements of 40 to 70 °C. Effective screening of polymers has benefited from dissolution/viscosity, thermal stability and filtration tests. At lower temperatures (40 °C), polymers were shown to be fit-for-purpose for the conditions evaluated. All polymers showed loss of viscosity with some leading to complete viscosity loss at increased temperatures. This is the result of hydrolysis and interaction with the divalent cations present in the make-up synthetic brine. In-situ viscosity allowed for identification of phase behaviour effects which could affect injectivity (difference in apparent and rheometer viscosity). For the best performing polymer the presence of corrosion and scale inhibitors did not affect viscosity. No detrimental effects on corrosion inhibition and water in oil emulsions were observed. Increases in oil in water with potential fouling/deposition was identified for future study.
Replacement of the C6ORF66 Assembly Factor (NDUFAF4) Restores Complex I Activity in Patient Cells
Authors: Marcus Dana , Lichtenstein Michal , Saada Ann , Lorberboum-Galski Haya 
Published: July 2013

AbstractDisorders of the oxidative phosphorylation (OXPHOS) system frequently result in a severe multisystem disease with the consequence of early childhood death. Among these disorders, isolated complex I deficiency is the most frequently diagnosed, accounting for one-third of all cases of respiratory chain deficiency. We chose to focus on complex I deficiency, caused by mutation in the assembly factor chromosome 6, open reading frame 66 (C6ORF66; NADH dehydrogenase [ubiquinone] complex I assembly factor 4 [NDUFAF4]) protein. We used the approach of cell- and organelle-directed protein/enzyme replacement therapy, with the transactivator of transcription (TAT) peptide as the moiety delivery system. This step will enable us to deliver the wild-type assembly factor C6ORF66 into patient cells and their mitochondria, leading to the proper assembly and function of complex I and, as a result, to a functional OXPHOS system. We designed and constructed the TAT-ORF fusion protein by gene fusion techniques, expressed the protein in an Escherichia coli expression system and highly purified it. Our results indicate that TAT-ORF enters patients’ cells and their mitochondria rapidly and efficiently. TAT-ORF is biologically active and led to an increase in complex I activity. TAT-ORF also increased the number of patient cells and improved the activity of their mitochondria. Moreover, we observed an increase in ATP production, a decrease in the content of mitochondria and a decrease in the level of reactive oxygen species. Our results suggest that this approach of protein replacement therapy for the treatment of mitochondrial disorders is a promising one.
Genetic Markers of a Munc13 Protein Family Member, BAIAP3, Are Gender Specifically Associated with Anxiety and Benzodiazepine Abuse in Mice and Humans
Authors: Wojcik Sonja M. , Tantra Martesa , Stepniak Beata , Man Kwun-nok M. , Müller-Ribbe Katja , Begemann Martin , Ju Anes , Papiol Sergi , Ronnenberg Anja , Gurvich Artem , Shin Yong , Augustin Iris , Brose Nils , Ehrenreich Hannelore 
Published: July 2013

AbstractAnxiety disorders and substance abuse, including benzodiazepine use disorder, frequently occur together. Unfortunately, treatment of anxiety disorders still includes benzodiazepines, and patients with an existing comorbid benzodiazepine use disorder or a genetic susceptibility for benzodiazepine use disorder may be at risk of adverse treatment outcomes. The identification of genetic predictors for anxiety disorders, and especially for benzodiazepine use disorder, could aid the selection of the best treatment option and improve clinical outcomes. The brain-specific angiogenesis inhibitor I-associated protein 3 (Baiap3) is a member of the mammalian uncoordinated 13 (Munc13) protein family of synaptic regulators of neurotransmitter exocytosis, with a striking expression pattern in amygdalae, hypothalamus and periaqueductal gray. Deletion of Baiap3 in mice leads to enhanced seizure propensity and increased anxiety, with the latter being more pronounced in female than in male animals. We hypothesized that genetic variation in human BAIAP3 may also be associated with anxiety. By using a phenotype-based genetic association study, we identified two human BAIAP3 single-nucleotide polymorphism risk genotypes (AA for rs2235632, TT for rs1132358) that show a significant association with anxiety in women and, surprisingly, with benzodiazepine abuse in men. Returning to mice, we found that male, but not female, Baiap3 knockout (KO) mice develop tolerance to diazepam more quickly than control animals. Analysis of cultured Baiap3 KO hypothalamus slices revealed an increase in basal network activity and an altered response to diazepam withdrawal. Thus, Baiap3/BAIAP3 is gender specifically associated with anxiety and benzodiazepine use disorder, and the analysis of Baiap3/BAIAP3-related functions may help elucidate mechanisms underlying the development of both disorders.