bluuebunny/crossref_metadata_2025_split huggingface dataset:
Successful Cold Heavy Oil Production with Sand (CHOPS) Application in Massive Heavy Oil Reservoir in Sudan: A Case Study
Authors: Ruifeng Wang , Xintao Yuan , Xueqing Tang , Xianghong Wu , Xinzheng Zhang , Li Wang , Xiaoling Yi 
Published: December 2011

Abstract
This paper demonstrates application of Cold Heavy Oil Production with Sand (CHOPS) in Sudan, which has been successfully applied in B heavy oil reservoir of FN field. B reservoir is a series of massive sandstones with strong bottom water drive, which are loosely consolidated and interbedded with shale barriers. Burial depth is 1250 m, average net pay thickness is 35 m. In-situ viscosity is around 300 mPa.s. Cold production well tests indicated average productivity of 500 BOPD, 2-3 times of sand controlled productivity. Global heavy oil fields with successful CHOPS histories have been investigated to confirm applicability in B reservoir and identify two major challenges of CHOPS application in B reservoir: 1) arresting rapid bottom water coning; 2) managing sand production in borehole and surface. CHOPS production strategy has been optimized by following approaches: 1) perforation ratio optimization based on fine barriers (interbed/intrabed) characterization and numerical simulation to avoid rapid coning; 2) borehole PCP lifting and surface de-sanding facilities optimization for sand control.
70 producers have been commissioned from 2004 to 2006 with optimized perforation ratio of 30% (total net pay), water cut has been kept below 10% with 2% annual offtake rate. Since 2007, 40 infill wells inclusive of horizontal wells have been drilled to further suppress water coning. Recovery factor to date is 13% with WCT of 46% as of 2010, demonstrating better performance than similar heavy oil reservoirs. Producers’ up-efficiency has been kept above 85%. Conclusions drawn from successful CHOPS application in B reservoir were as follows:1) optimized perforation contributed to low water cut in early stage; 2) infill well beneficial to suppressing WCT in middle stage; 3) optimized lifting and facilities contributed to high production up-efficiency.
Heavy oil reserves takes 40% of Sudan’s total reserves, therefore CHOPS has wide applications for similar Sudanese and African fields.
Successful CHOPS in this paper highlighted fine barriers (interbed/intrabed) characterization and optimized perforation strategy, infill well drilling, optimized borehole lifting and facilities design, giving a cost-effective staircase for CHOPS implementation.
Radio Frequency Heating, Oil Sand Recovery Improvement
Authors: Godard A. , Rey-Bethbeder F. 
Published: December 2011

Abstract
Today’s techniques to recover heavy oil are mining, when possible, or steam injection. For steam injection, once the oil is heated, its viscosity is reduced; it becomes mobile and can be extracted. In some cases, when steam injection isn’t efficient, other methods should be developed, one of them is based on electrical technology.
One solution studied by Total to reduce viscosity when steam injection isn’t possible or efficient, is to use Radio Frequency heating. The electromagnetic waves have the capability to heat immediately deeper than steam. To improve efficiency of this process, we developed a downhole Radio Frequency generator composed of triodes. An antenna is added to form a complete assembly. Here, we will present the advantages of this original solution patented by Total.
The optimization of this device concerns the impedance adaptation between generator and the antenna. But the impedance of this antenna depends also on the electrical characteristics of the reservoir. The reservoir’s impedance is mainly determined by the water in liquid phase. One critical parameter is the complex electric permittivity. This parameter impacts directly on the conversion from the electrical energy to heat, the dissipated power in the reservoir being related to the complex part of the permittivity.
In this paper, we will show a solution to keep an optimum conversion ratio from high frequency electrical energy to heat. As the impedance varies with time and reservoir heating, the optimum radiating frequency of our system has to vary too. The choice of the central frequency could also depend on the presence of iron oxide in shale layer in the hydrocarbon reservoir. In this paper, we will choose a frequency around 10 MHz and we will show different spatial repartitions of the applied electrical field and the corresponding heated zone. The frequency band is a compromise between fast heating and depth of penetration: the lower the frequency, the deeper the electromagnetic waves penetrate in the reservoir.
Full Field Modeling of Wafra First Eocene Reservoir 56-year Production History
Authors: Rubin Eugene 
Published: December 2011

Abstract
A noticeable increase in a carbonate reservoir permeability (relative to that of core) and calibration of the reservoir mobile water saturation resulted from its black model history match to 56-year primary production history.
The First Eocene carbonate reservoir of Wafra field contains a large amount of heavy oil (13-19 °API). Primary recovery since 1956 has been approximately 4 percent of the net OOIP. Steamflood has been piloted in the field since 2005. Full field steamflood performance forecasting relies heavily on reservoir simulation, which requires proper calibration of models. Long history of the field primary production is a valuable source of information for such a calibration.
Based on core data, the reservoir is not considered fractured and was modeled as a single porosity system. The model initial average horizontal permeability was about 200 md with a maximum of about 1000 md. The 258-million-cell full field geostatistical model was upscaled to a 3.6-million-cell simulation model with the reservoir heterogeneity preserved. Oil viscosity depth variation was incorporated.
The model was matched satisfactorily. Well productivity indices were increased to enable each of more than 300 wells to produce at reported liquid rates. Permeability was globally increased. An aquifer was included to match reservoir pressure. Resulting average horizontal permeability did not exceed 2-3 Darcy. Recent MDT tests support this permeability level.
Irreducible water saturation (Swir) was modified to match water production. First approximation of Swir was based on core data. Then Swir was multiplied by a factor. The resulting amount of mobile water seems modest within the producing interval and rapidly growing towards the OWC. This mobile water may become a steam thief zone.
The calibrated distributions of model permeability and mobile water will be used in steamflood forecasting.
Challenges of Drilling Horizontal Wells in Shallow Viscous Oil Formations
Authors: Dutta Bikramjit , Al-Azmi Bader M. , Sanyal Tirtharenu , Dutta Abhijit , Fernandes Warren , Zaki Mohammed 
Published: December 2011

Abstract
The viscous oil resource of Kuwait poses special challenge since about 40-50% of the resource is distributed over a very large area with pay thickness in the range of only 20-30 ft. These low pay thickness areas are considered marginal for conventional thermal EOR and may need an innovative approach for economic exploitation. Horizontal wells, both for primary production as well as for thermal EOR, have been successfully used in such reservoirs (Araque-Martinez et.al. 1996, Malik, S. et.al, 2010). In this context, drilling of horizontal wells for this viscous oil reservoir is considered a key milestone for development of this vast resource.
The challenges for the shallow viscous oil formation drilling, requires shallow horizontal medium-radius wells in extremely soft formation, with kick off from 150 ft MD. The initial plan was to drill six horizontal wells in the early phase, followed by a field study, before further expansion into horizontal drilling. Baker Hughes has successfully drilled three horizontal wells of the six wells, and has set the benchmark for shallow horizontal medium-radius wells in the extremely soft Shallow viscous oil formations formation. The horizontal wells require kick off from 150 ft MD in the loose sand formation of Shallow viscous oil formations, posing a strong directional drilling challenge. Maximum TVD for the wells are approximately 715 ft TVD RKB, which requires landing the wells in less than 5 ft TVD, with tolerance for navigation in the 6.125 in. lateral section within +/-1 ft (i.e., less than bit OD). The requirement is to geosteer along reservoir sand with the help of proactive geosteering services, maintaining optimum drilling parameters for good borehole quality. The solution included the geosteering services with rotary steerable systems, LWD density, porosity and distance-to-bed boundary tools. With average horizontal section lengths of 1,100 to 1,200 ft, drilled in reservoir sand of shallow viscous oil formations formation, Baker Hughes has drilled the longest horizontal section of 1,307ft in the soft formations. The synchronized team efforts from Kuwait Oil Company along with the Baker Hughes team resulted in consistent good execution of the three shallow horizontal medium-radius wells in Shallow viscous oil formations project, with optimal well placement, achieving 100-percent reservoir exposure.
Impact of Reservoir Heterogeneity on Steamflooding, Wafra First Eocene Reservoir, Partitioned Zone (PZ), Saudi Arabia and Kuwait
Authors: Meddaugh W. Scott , Osterloh W. Terry , Toomey Niall , Bachtel Steve , Champenoy Nicole , Rowan Dana , Gonzalez Gregorio , Aziz Shamsul , Hoadley S. F. , Brown J. , Al-Dhafeeri F. M. , Deemer A. R. 
Published: December 2011

Abstract
The Paleocene/Eocene age First Eocene dolomite reservoir is estimated to contain than 10 billion barrels of oil of which only a small percentage will be produced during primary development. Consequently, steam flooding is being investigated as an appropriate EOR option. A 1.25-acre, single pattern pilot (SST) and a 40-acre, 16 pattern pilot (LSP) are in progress. The detailed pilot area log, core, and seismic data provide a unique opportunity to assess reservoir heterogeneity. Analysis of temperature and petrophysical logs obtained in a temperature observation well located 35 feet from the SST injector show that a vertical barrier to steam migration exists. Two, relatively thick, very low porosity and very low permeability nodular evaporite-rich zones that were predicted to be the most likely barriers do not appear to be a vertical barrier. Instead, an interval characterized by numerous thin, cycle caps, characterized by muddy, finely crystalline dolomites interpreted to be tidal flat facies may be the vertical barrier. Each of these cycle caps also exhibit signs of subaerial exposure which may also contribute to the generally low porosity and very low permeability of the cycle caps. Detailed studies, including micro-permeameter measurements, quantitative mineralogical studies, and micro-CT scans were used to further characterize this interval. The geological assessments of heterogeneity are supplemented by a history-matched simulation model that suggests the evaporite-rich zones may have acted as short term baffles but that the vertical barrier to steam migration is coincident with the interval with abundant tidal flat cycle caps and exposure surfaces. Geological and other reservoir data obtained from the LSP suggest that similar vertical barriers may exist in the pilot area. Early steamflooding results show a very positive response to steam injection as well as multiple thermal "events" (most likely baffles rather than barriers) in the lowermost flooded zones at the LSP. The LSP data allows inferences to be made regarding the occurrence and distribution of lateral high permeability "connections" between injectors and producers as well as the overall reservoir response to steam injection. While the rapid temperature response observed in a few wells may reflect localized fractures or karst-like zones, numerical simulation using very fine grids (1.25 m cell size) shows that some of the LSP wells may experience very short breakthrough times without the need for fracture or karst-like zones.
Steamflood Pilot Design for the Wafra Field 2nd Eocene Reservoir in the Partitioned Zone (PZ), Saudi Arabia and Kuwait
Authors: Gross Stephen J. , Johansen Steven J. , Perinot Tomas , Deemer Arthur R. , Hoadley Steven F. , Meddaugh W. Scott 
Published: December 2011

Abstract
The 2nd Eocene dolomite reservoir in the Wafra field is an attractive target for enhanced oil recovery (EOR) because of its large resource base and low primary oil recovery. Primary oil recovery is low because of heterogeneity, low oil gravity, and lack of significant aquifer support. Screening studies and numerical simulations indicate that steamflooding is the most attractive EOR method in terms of reserves and economics. Key technical challenges in steamflooding the 2nd Eocene reservoir include reservoir heterogeneity, relatively high reservoir pressure, scale deposition and corrosion due to rock-steam interactions, and uncertainty regarding the location and impact of barriers to vertical steam migration.
A pilot steamflood was designed to test the viability of steamflooding the 2nd Eocene. The pilot location was selected based on a number of criteria including reservoir quality and proximity to existing steam generation facilities. Several pattern configurations were evaluated based on their ability to depressurize the reservoir and to yield timely information, taking into account steam availability considerations. Based on these considerations, a configuration of seven 2.5-acre inverted 7-spot patterns was chosen for the pilot. Steam injection rates were designed to yield steam breakthrough after approximately one year of steam injection.
A robust surveillance plan was developed to collect the data necessary to satisfy the pilot objectives and to understand the critical reservoir uncertainties. The surveillance plan was carefully considered in the well and surface facilities designs to ensure that all required measurements could be made with minimal impact on operations. Reservoir simulations indicate that a significant amount of fluid influx will occur from the reservoir surrounding the pilot after steam breakthrough, thereby obscuring the steamflood production response. For this reason a dense array of observation wells was designed to monitor reservoir temperatures and saturations and to provide enough information to understand fluid movement, steam chest development, and steamflood recovery factors in the presence of this influx. A thorough understanding of these mechanisms will be crucial for making future steamflood expansion decisions.
In-Situ Upgrading of Bitumen and Shale Oil by RF Electrical Heating
Authors: Snow Richard H. 
Published: December 2011

Abstract
The objectives of upgrading oil sands bitumen are: Reduce viscosity so that product can be pipelined to a refinery without building a costly above-ground upgrading plant, which requires water and auxiliary fuel such as natural gas.Reduce the cost and amount of upgrading required in the refinery.Reduce the amount of sulfur, nitrogen, and heavy metals which cause problems with refining catalysts, since these elements tend to concentrate in the heaviest molecules, which end up in the coke.Sequester the coke in the ground. In-situ upgrading is also desirable for oil shale.
There have previously been reports that upgrading occurs during pyrolysis, but it has not been clear what conditions lead to upgrading. Low temperature (300-350 °C) is economically desirable to minimize cost for RF electric heating of deposits, yet there have been suggestions that low temperature favors coke formation. Both physical and chemical variables affect upgrading, and we attempt to explain these complications.
In the following, pyrolysis experimental methods and data are reviewed. Reaction kinetic models to represent the data are reviewed, and used to calculate low temperature product distributions. These results are replotted as product distillation curves and interpreted to show how upgraded product can be produced. Models indicate that coke is formed after a sequence of reaction steps, so its appearance is slow. Therefore light product can be harvested early, before material reacts further producing excessive coke. Data on Western US oil shale are also reviewed and similar conclusions are drawn. Further reservoir engineering studies are needed to optimize production of light oil.
An Integrated Technology Development Plan for Solvent-based Recovery of Heavy Oil
Authors: Boone Thomas J. , Wattenbarger Chick , Clingman Scott , Dickson Jasper 
Published: December 2011

Abstract
ExxonMobil and its Canadian affiliate Imperial Oil Resources are pursuing an integrated research program targeted at developing the next generation of heavy oil recovery processes which utilize hydrocarbon solvents as a mobilizing agent. The key benefits of solvent-based processes are improved environmental performance, improved economics and recovery of resource that is impractical with thermal processes.
The integrated research program encompasses fundamental laboratory work, analytical modeling, advanced numerical modeling, scaled physical modeling in the laboratory, a solvent-only pilot which is in the design phase, an operating solvent-assisted SAGD pilot and a first commercial scale application of a solvent-assisted cyclic steam stimulation (CSS) process known as Liquid Addition for Steam Enhanced Recovery (LASER). This paper provides a systematic review of the scope, technical challenges, benefits and successes of research efforts in each of the areas cited above. In general, the results of laboratory modeling and simulation studies are strongly supportive of the potential success of solvent-assisted and solvent-based recovery processes. Reliably demonstrating solvent recovery processes at the field scale remains a key challenge that can only be addressed through well designed field pilot programs and enhanced reservoir surveillance programs for commercial scale applications. These challenges are highlighted in the paper utilizing specific examples from the integrated research program.
In conclusion, there are some very significant technical challenges that need to be addressed before solvent-assisted and solvent-based heavy oil recovery processes will be broadly commercialized. Nonetheless, consideration of the results across the full breadth of ExxonMobil's integrated technology program provides strong support that a new generation of solvent recovery processes will emerge as an economically competitive option for heavy oil recovery with significant environmental benefits relative to today's thermal recovery processes.
Free Speech in the Balance: An Examination of Yahoo! Inc. v. La Ligue Contre Le Racisme et L'Antisemitisme for its Bearing on Conflict of Laws, Global Free Speech, and the International Regulation of the Internet
Authors: Ziaja Andrew J. 
Published: December 2011

Abstract
The global proliferation of the Internet, given the ease with which it permits transnational communication, calls into question the applicability of traditional territorial legal systems in governing its use. Conflict-of-laws instruments and the regulation of speech are two thorny areas of concern in this vein that interrelate in a 2006 case before the Ninth Circuit Court of Appeals in the United States, Yahoo! Inc. v. La Ligue Contre Le Racisme et L’Antisemitisme. Yahoo! offers an entry point, through its bearing on conflict-of-laws and freedom of speech jurisprudence, into examining the appropriateness of traditional legal schemes to the task of regulating Internet-enabled conduct. Focusing on the substantive issues in Yahoo!, this paper takes up the adequacy of traditional conflict-of-laws instruments as regards Internet-enabled conduct, possible alternatives to the use of conflict-of-laws instruments to regulate Internet-enabled conduct, the applicability and weight of the French law against the First Amendment in a United States court, and, finally, the possibility of developing a common core of global values regarding speech on the Internet.
Role of interfacial chemistry on the rheology and thermo-mechanical properties of clay-polymer nanocomposites for building applications
Authors: Huynh Hieu-Thao , Benzarti Karim , Duc Myriam 
Published: December 2011

AbstractThis study is directed towards investigating the role of the surface treatment of clay particles on the rheological and thermomechanical behaviour of clay-epoxy blends. Nanocomposites were prepared by mixing small amounts (5–10 mass %) of commercial organoclays or raw clays with an epoxy system commonly used in civil engineering. Rheological characterisations in the liquid state revealed a pronounced thixotropic character of the organoclay-based systems, which all exhibited a shear-thinning behaviour above a critical stress threshold (yield stress), depending on both the intensity of interfacial interactions and the degree of filler dispersion. On the other hand, systems based on raw clay particles behaved like Newtonian fluids, in the same way as the unreinforced polymer matrix. Complementary dynamic mechanical analyses (DMA) performed on the cured cross-linked nanocomposites also showed significant changes in the viscoelastic behaviour of the epoxy matrix due to the introduction of organoclays, whereas only minor variations were observed following the introduction of raw fillers. These results were consistent with nanoscale morphological characterisations performed by conventional X-ray diffraction (XRD) on the various hybrid systems. In this context, rheology and DMA appear as attractive alternative methods for assessing the filler dispersion at a macroscopic (and possibly more relevant) scale. This research is of practical interest for civil engineers, since clay reinforced-epoxies could in the future be used as coating materials with enhanced barrier performances, in order to protect infrastructures against environmental ageing or corrosion.
Design of polyglycidol-containing microspheres for biomedical applications
Authors: Basinska Teresa , Slomkowski Stanislaw 
Published: December 2011

AbstractThe paper presents a short review on the synthesis, characterisation and selected medical applications of poly(styrene/α-tert-butoxy-ω-vinylbenzyl-polyglycidol) (P(S/PGL)) microspheres. The soap-free emulsion-polymerisation of styrene and α-tert-butoxy-ω-vinylbenzyl-polyglycidol macromonomer (PGL) in water yielded core-shell microspheres with a low particle-diameter dispersity (ratio of the weight average particle diameter and the number average particle diameter). The interfacial fraction of PGL units, estimated by XPS, was in the range of 0–42 mole % depending on the concentration of the macromonomer in the polymerisation feed. The studies of adsorption of model proteins showed that the surface fraction of adsorbed protein was significantly reduced when the PGL interfacial fraction was higher than 40 mole %. The P(S/PGL) particles with covalently immobilised proteins were used for the preparation of photonic crystal assemblies suitable for applications in optical biosensors and the medical diagnostic test for the detection of Helicobacter pylori antibodies in the blood serum.