bluuebunny/crossref_metadata_2025_split huggingface dataset:
Multi Lateral Horizontal Well Application for Improving the Oil Recovery of a Mature Field, Intisar N. Field, Concession 103— Libya
Authors: Gharsalla Mohamed M. , Elghmari Mohamed B. 
Published: March 2008

Abstract
This paper examines the performance of a horizontal well with multi-lateral completion in a mature thin carbonate reservoir. The Upper Sabil reservoir in Zelten formation of Paleocene age in Intisar 103N Field has a structure of anticline that housed 14.4 MMSTB of OOIP. The reservoir was highly under-saturated with oil of 42° API.
The initial field development with two vertical wells resulted in a poor recovery of only 9 % of OOIP. The recovery mechanism of Upper Sabil reservoir is mainly rock/fluid expansion with marginal support from flank aquifers. The poor recovery can be attributed to thin pay thickness, poor reservoir quality, large well spacing, and lack of pressure support from aquifers.
The existing two vertical wells revealed a near constant production rate for the last 17 years indicating the drainage area is much larger than the wells can deplete in a reasonable time frame. The incentive of reducing well spacing was there but the question was how to reduce the well spacing: by drilling many vertical wells or less number of horizontal wells.
A reservoir simulation study in 2003 indicated that drilling vertical wells in a very thin reservoir of poor quality was not cost effective and recommended drilling of horizontal well. Hence, a horizontal well was drilled and completed at the top of the porosity with two lateral legs.
The stabilized oil production rate of the horizontal well was approximately three times higher than that of the vertical well, whereas the drilling cost of the horizontal well was about 1.5 times higher. The production from the horizontal well showed no negative impact on the production performance of the existing vertical well and the reserve was doubled.
Imaging the Deep Mediterranean Through Multi-Azimuth Seismic Acquisition and Processing
Authors: Rietveld Walter , Keggin Jim , Benson Mark , Manning Ted , Page Chris 
Published: March 2008

Abstract
At a depth of around 3km across large areas of the Nile Delta in the Mediterranean, lies a thin but complex layer of partially eroded Miocene aged anhydrite and other facies, refered to as the Messinian. Wavefield distortion, attenuation and the generation of complex multiple diffraction noise cause the quality of the underlying seismic image to be highly variable (See Figure 1). Multi-azimuth (MAZ) seismic can help resolve these issues and improve the deep pre-Messinian image.
Here we discuss the acquisition and processing flow of a MAZ streamer datasets and show some of the results. The initial data analysis shows that MAZ greatly improves general image quality, signal-to-noise ratio, lateral resolution, as well as suppressing diffracted and other multiples effectively. Issues and challenges around this approach are discussed.
Optimizing Hydraulic Fracturing in a Mature Oil Reservoir in Algeria
Authors: Shaoul J. R. , Spitzer W. , Mendenhall S. , Soufi S. , Aloun S. 
Published: March 2008

Abstract
The El-Agreb field, located near Hassi Messaoud, Algeria, has been producing for over 40 years. Hydraulic fracturing was attempted in the mid 1990's with some success. This paper describes the results of a study of 11 stimulation treatments performed in the Agreb field from 1994-2003. Fracture modeling using net pressure history matching gave estimates of fracture dimensions and reservoir permeability. Fracture dimensions and conductivity data went into a reservoir simulator and the post-frac production was history matched by adjusting the effective proppant permeability.
Analysis of the pre and post-frac productivity indexes (PI) was done to determine the productivity improvement factor (PIF). This analysis showed a clear correlation between the PIF and the dimensionless fracture conductivity (FcD). Such a correlation would only be expected in the case of finite conductivity fractures. For all the propped fractures, the "ideal" fracture conductivity (assuming 50% proppant permeability damage) gave an FcD greater than 1.5 (with an average FcD of 12). History matching the actual post-frac production, however, required proppant damage factors up to 97%, giving effective FcD's as small as 0.1. The proppant damage factor needed to match post-frac production was a strong function of the "ideal" FcD of the fracture. This result indicates that for good cleanup of the gel in the proppant pack, higher fracture conductivity is necessary than what would be considered sufficient based only on reservoir permeability and ideal values of proppant permeability. Previous work has made this claim1, and this field data strongly supports the earlier work. A large number of El Agreb fracture treatments were analyzed and a calibrated fracture model developed, allowing more accurate design of tip screenout treatments. Due to the low reservoir pressure in this mature field, a large differential pressure drives fracture leakoff, making spurt loss important2. The calibrated model has been applied successfully to 14 new fracture treatments in 2003-2007 (11 producers and 3 injectors). The benefits of this approach are improved productivity and more rapid post-fracture cleanup. New wells drilled in the field are now usually immediately fracture stimulated.
A Thermal Recovery Method for Medium-Heavy Oil Reservoirs
Authors: de Zwart A. H. , Bakker P. , Glandt C. A. , Brooks A. D. , van Dorp J. 
Published: March 2008

AbstractThe primary recovery of a medium-heavy oil reservoir with a strong bottom aquifer is generally poor. The introduction of horizontal wells that are drilled at the top of the oil column has improved the oil recovery. However, even horizontal wells suffer from fast water breakthrough that leads to oil production at a high water cut. Given the low primary recoveries, such fields are attractive EOR targets.In situ combustion (ISC) is a displacement process generally applied to medium-heavy oil reservoirs in order to increase oil production by reducing the oil viscosity. In thick reservoirs (thicker than 10 meters), oil recovery could be severely challenged by gravity override of the injected gasses. In reservoirs without active aquifers, a significant part of the incremental oil is produced by gravity drainage after breakthrough.We propose an ISC strategy where an infill producer is drilled close to the oil-water contact so that a significant amount of heat can be rapidly deployed in the middle and upper sections of the reservoir. Subsequently, the aquifer is used to sweep the warm oil through the heated zone towards the producers. The ISC process is compared with steam injection that also employs an additional infill producer. ISC and steam injection are used to deploy heat in the reservoir.Numerical simulations show that the oil is produced at much lower water cut compared to the cold case (50-60 % versus 95%). Simulated oil recoveries increase significantly for both ISC and steam injection. A detailed comparison of these two processes is presented in this paper.
Practical Aspects of Streamline Application to Water Injection Management of a Giant Carbonate Reservoir
Authors: Rodriguez Alfonso , Dawood Naseem J. , Soremi Yinka , Taiban A. 
Published: March 2008

Abstract
This paper presents how streamline technology in combination with conventional water injection management indicators was used to effectively manage water injection in a giant field. Describing the relationship between injectors and producers is obtained from a streamline simulation model. Adjusting injection requirements only, based on well streamline injection efficiencies, is not possible for all regions of the reservoir since a good history-match is not always achieved in all regions, particularly for a giant simulation model with 520 producers and 160 injectors. Thus, conventional water injection management indicators like injection/production ratio(IPR) target per segment, reservoir pressure distribution and maximum water injection plant facilities should be taken into consideration to distribute the water efficiently.
The new proposed methodology, through an iterative process, links the streamline simulation results to the practical aspects of conventional peripheral water injection management considering water injection facilities constraints and routine reservoir performance metrics. The new approach improves injection efficiency for all segments simultaneously in a single run. We have accounted for redistributing water injection among several segments connected to a single/multiple water injection plants (WIPs). Results indicated that a similar oil production rate can be obtained through optimization. The main benefit is that water injection is managed more effectively with the excess amount of water not injected in a particular month or quarter, could be transferred and injected into other fields.
The Role of Multi-Disciplinary Teams in Innovative Reservoir Management Projects
Authors: Thakur Ganesh 
Published: March 2008

AbstractThis paper documents the use of integrated reservoir management concepts during the application of innovative technology to improve oil production/recovery in both new and mature fields. It provides a number of examples of multi-disciplinary project teams working together in a motivated environment to optimize the asset value. These examples demonstrate the innovative use of existing technologies to increase asset productivity: 3D/4D seismic, geostatistics, characterization/simulation, horizontal drilling technology, and improved oil recovery (IOR)/enhanced oil recovery (EOR) techniques — dumpflooding, peripheral/pattern floods, water/gas injection, CO2/miscible gas, and steamflooding.Adopting an integrated team approach is important because of the advanced level of expertise required in making large-scale primary, secondary and tertiary projects successful from both a technical and an economic point of view. Opportunities for improving recovery through synergistic activities among team members are numerous. The integrated team approach and innovative use of technologies have resulted in significant increase in production/recovery in each of the case studies. Moreover, multi-disciplinary functions can yield significant benefits and individual job satisfaction for the participating team members.A team building approach that uses "in-house" reservoir management quality fitness reviews or mini-forums are often employed to facilitate communication among engineering, geosciences, and operations staff. Recommendations for project improvement are a natural outgrowth of these forums.Our experience indicates that considerable corporate benefits can be derived from integrated, multi-disciplinary reservoir management activities for both new and mature fields, onshore or offshore.
Geomechanical Aspects of 15 Years Water Injection on a Field Complex: An Analysis of the Past to Plan the Future
Authors: Santarelli F. J. , Havmøller O. , Naumann M. 
Published: March 2008

Abstract
This paper presents an analysis of the water injection conditions on a vast oil field complex operated by StatoilHydro in the Norwegian sector of the North Sea over a fifteen years period. The injection data were analysed from a geomechanical perspective such as to identify the main parameters governing the variations of fracturing pressure over the life of the wells, which in turn governs efficient and safe water injection.
The data highlight the importance of thermal effects in fracturing pressure variations even in relatively weak formations, where theory would deem them small based upon laboratory measurements. The magnitude of thermal effects quantified from field measurements is about one order of magnitude larger than what was expected a-priori from laboratory measurements.
It was also possible to track the evolution of the fracturing pressure of single wells for various reservoir pressures during phases of reservoir re-pressurisation. Here again the field data indicate behaviours that were not expected from a theoretical point of view – i.e. a constant fracturing pressure during reservoir re-pressurisation, while theory would predict a significant increase.
The practical implications of the study when designing water injection schemes on new fields are highlighted and examples are given on how the current theoretical short-comings identified during the study can be successfully by-passed in real life engineering. The need for R&D efforts aimed at matching the gap between field observations and existing theories is also emphasised.
High Density Brine-Based Drill-In Fluid Improved Reservoir Producibility in Gas Field Offshore Egypt
Authors: Ezzat A. M. , Gamal Medhat , D'Angelo Stefano 
Published: March 2008

AbstractQuick clean up and dramatic improvements in reservoir producibility have been achieved in gas wells located offshore Egypt. These wells were drilled and completed using an engineered drill-in fluid system. The fluid formulation was carefully designed and extensively tested in three different laboratories prior to the field applications to help ensure reproducibility of the data and to verify the non damaging characteristics of the fluid. These tests were conducted under simulated downhole conditions to help ensure fluid compatibility with the reservoir rock minerals and natural fluids.To help minimize fluid invasion while drilling in the payzone section, the optimal concentration and particle size distribution (PSD) of the suspended bridging material were selected and maintained during the field applications. The PSD of pure ground marble was selected based on the reservoir rock morphology and average pore size to establish effective bridging near the wellbore and help ensure quick lift-off of the filter cake.A high-density calcium chloride / calcium bromide brine blend (14-14.5 lb/gal ≃ 1.68 sp.gr.-1.74 sp.gr.) was used as the base fluid to achieve and maintain the required fluid density without additions of insoluble weight material. Optimal concentrations of non-damaging temperature-stable polymers were used to provide suspension and filtration control. The gas reservoir section was drilled and completed in several wells with the new system. Productivity index and flow rates exceeded the operator’s expectations without any stimulation treatments. Substantial savings were realized in terms of rig time and well completion costs.This paper presents the laboratory and field-generated data and discusses the key issues in designing and monitoring the new drill-in fluid during the field applications.
Discrete versus In Situ‐Generated Aluminum‐Salen Catalysts in Enantioselective Cyanosilylation of Ketones: Role of Achiral Ligands
Authors: Alaaeddine Ali , Roisnel Thierry , Thomas Christophe M. , Carpentier Jean‐François 
Published: March 2008

AbstractThe monometallic species {Salen}AlX (X=Me, 2a,b; X=Cl, 4a,b; O‐i‐Pr, 5a,b) and open bimetallic species {Salen}[AlMe2]2 (3a,b) that result from binary combinations between an aluminum precursor [trimethylaluminum, dimethylaluminum chloride, aluminum tris(isopropoxide)] and a diprotio {Salen}H2 pro‐ligand 1a,b (a=1R,2R‐cyclohexyl‐salen; b=1R,2R‐diphenylethylene‐salen) have been isolated. The crystal structures of 3b, 4b and of μ‐oxo species [{diphenylethylene‐salen}Al]2O (6b) are reported. The discrete species 2–5a,b have been individually evaluated in the asymmetric cyanosilylation of acetophenone. It is shown that, in several cases, these discrete catalysts display dramatically different performances than the catalyst systems in situ‐generated from the binary combinations. The influence of the achiral ligand X on both the enantioselectivity and activity of the cyanosilylation reaction has been investigated, resulting in the definition of a highly active and productive hexafluoro‐2‐propoxide‐based catalyst for a variety of aryl alkyl ketones (TON up to 470, TOF up to 140 h−1 at −20 °C for acetophenone).
Synthetic Applications of Synergism using Catalytic Binuclear Elimination Reactions. Further Examples of Rhodium‐Manganese and Rhodium‐Rhenium‐Catalyzed Hydroformylations
Authors: Li Chuanzhao , Chen Li , Garland Marc 
Published: March 2008

AbstractSynergism has been previously observed in both rhodium‐manganese‐ and rhodium‐rhenium‐catalyzed hydroformylation. Furthermore, detailed in situ spectroscopic investigations have conclusively shown that the phenomenological origin of this synergistic effect is catalytic binuclear elimination (J. Am. Chem. Soc. 2003, 125, 5540–5548; 2007, 129, 13327–13334). In the present contribution, further substrates are used in the hydroformylation reaction with both rhodium‐manganese and rhodium‐rhenium. In situ spectroscopic studies show that (i) significant rate enhancements occur in the mixed metal systems with the new substrates and (ii) the organometallics present in the active systems, and their concentration profiles are consistent with those present in the previously studied catalytic binuclear elimination reactions (CBER). It is therefore concluded that catalytic binuclear elimination is a rather general mechanism in mixed metal hydroformylations and is rather independent of the substrates used. Further discussion is given to mechanistic aspects, synthetic efficiency, and the possibility that such synergistic effects might be useful to other classes of organic syntheses.
Nanomaterials for Rechargeable Lithium Batteries
Authors: Bruce Peter G. , Scrosati Bruno , Tarascon Jean‐Marie 
Published: March 2008

AbstractEnergy storage is more important today than at any time in human history. Future generations of rechargeable lithium batteries are required to power portable electronic devices (cellphones, laptop computers etc.), store electricity from renewable sources, and as a vital component in new hybrid electric vehicles. To achieve the increase in energy and power density essential to meet the future challenges of energy storage, new materials chemistry, and especially new nanomaterials chemistry, is essential. We must find ways of synthesizing new nanomaterials with new properties or combinations of properties, for use as electrodes and electrolytes in lithium batteries. Herein we review some of the recent scientific advances in nanomaterials, and especially in nanostructured materials, for rechargeable lithium‐ion batteries.
Tetraoxaspiroalkanes for polymerization stress reduction of Silorane resins
Authors: Chappelow Cecil C. , Pinzino Charles S. , Chen Shin‐Shi , Kotha Shiva P. , Glaros Alan G. , Eick J. David 
Published: March 2008

AbstractThis study involved the synthesis and characterization of tetraoxaspiroalkane monomers and evaluated their potential to reduce polymerization stress when formulated in a Silorane resin system. The tetraoxaspiroalkane monomers had two main structural features (a) two different types of core ring structures (a 1,5,7,11‐tetraoxaspirocyclic ring or a 2,4,8,10‐tetraoxaspirocyclic ring) and (b) four different types of ring substituents (normal alkyl, allyloxyalkyl, trimethylsilylalkyl, or oxabicycloalkyl). The resin formulations contained (a) 20 mol % of a 1,5,7,11‐ or 2,4,8,10‐tetraoxaspiroalkyl monomer; (b) a phenylmethylsilane containing two oxabicycloheptyl groups; (c) a cyclotetrasiloxane containing four oxabicycloheptyl groups; and (d) a photocationic initiator system. Three main aspects were studied (a) the photoreactivity of the formulations using PDSC, (b) photopolymerization stress, and (c) mechanical properties (flexural elastic modulus, ultimate strength, and work of fracture) which were measured using an electromagnetic mechanical testing machine. The main findings were (a) formulations containing 2,4,8,10‐tetraoxaspiroalkane monomers had measured net enthalpies greater than those containing 1,5,7,11‐tetraoxaspiroalkane monomers, and above those calculated for addition of an inert diluent; (b) all formulations containing tetraoxaspiroalkane monomers exhibited photopolymerization stress values that were 40–99% less than the nonaddition control; (c) the formulation containing a 1,5,7,11‐tetraoxaspiroalkane monomer with an oxirane functionality had mechanical properties that were not significantly different from the nonaddition control. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Polymerization of acrylonitrile initiated by Ce(IV)‐sucrose redox system: A kinetic study
Authors: Mahadevaiah  , Demappa T. , Sangappa  , Katoon Bibi Ahamadi 
Published: March 2008

AbstractThe polymerization of acrylonitrile (M), initiated by the free radicals formed in situ in the Ce (IV)‐sucrose redox system, was studied in aqueous sulfuric acid medium under nitrogen atmosphere in the temperature range of 30–60°C. The rate of polymerization is proportional to [M]1.0, [R]0.76, [Ce(IV)]0.8, and [H+]−0.46. The rate of Ceric ion disappearance and the rate of polymerization Rp have been measured. The effects of some water–miscible organic solvents, surfactants, ionic strength, and complexing agents on the rate of polymerization were investigated. The temperature‐dependence of the rate was studied and the activation parameters were computed using the Arrhenius and Eyring plots. A mechanism consistent with the experimental data, involving Ce(IV)‐sucrose complex formation, which generates free radicals, is suggested. The chain termination step of the polymerization reaction was determined. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Synthesis of PNIPA/PDMS‐g‐PAA core‐shell composites in supercritical carbon dioxide
Authors: Cao Li‐Qin , Chen Liu‐Ping , Cui Peng‐Yuan , Wang Ji‐De 
Published: March 2008

AbstractHerein we report a means that has been developed to prepare smart polymeric microgels consisting of thermosensitive cores with pH‐sensitive shells. The microgels were obtained directly from seed polymerization of N‐isopropylacrylamide in supercritical carbon dioxide (scCO2). The effects of initial amounts of crosslinker, and Poly (dimethylsiloxane)‐graft‐polyacrylates (PDMS‐g‐PAA) on the yield and morphology of the resulting polymer were investigated. PDMS‐g‐PAA and crosslinker worked effectively as surfactant. PNIPA/PDMS‐g‐PAA particles with diameters in 50 nm were produced in scCO2, in high yield and in short reaction times. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Preparation and electroanalytical characterization of polyaniline: Polyacrylonitrile composite films
Authors: Khatoon Atika , Khalid Mohd , Mohammad Faiz 
Published: March 2008

AbstractElectrically conducting composite films of polyaniline:polyacyrlonitrile (PANI:PAN) prepared with varying composition ratios of aniline mixed with a fixed amount PAN. The films of optimum thicknesses (0.10 mm) were obtained using an electrically operated automatic pressure machine. The films polymerized by oxidative polymerization using 0.1M potassium persulphate (K2S2O8), undoped in 1M aqueous ammonia (NH4OH) and doped in 1M hydrochloric acid (HCl). The conductivity of composite films was studied by keeping it in 1M HCl for different time period using 4‐in‐line probe DC electrical conductivity measuring instrument and the temperature dependence of DC electrical conductivity was studied using isothermal technique. The PANI:PAN composite film is used as a working electrode in an electrochemical cell. Chemically doped composite film is used as cathode (working electrode), aluminum metal foil as anode (counter electrode) and platinum foil as reference electrode. The electrolyte is of 0.05M aluminum chloride (AlCl3) in dimethyl sulfoxide (DMSO). The voltage of the working electrode is stabilized with respect to the reference electrode and current applied between the working and counter electrode through a 9‐V battery. The change in voltage versus time is plotted as the discharge curve and reversing the cell processes results in the doping of the composite films. The diffusion coefficient of the dopant ion (Cl−) present in the fully doped films were estimated by the galvanostatic pulse technique and found to bedifferent in different samples in the range of 10−16 to 10−12 cm2 s−1. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008