bluuebunny/crossref_metadata_2025 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

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

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

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

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

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

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

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

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

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

This 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

The 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.
Emergence of Delayed Posttraumatic Stress Disorder Symptoms Related to Sexual Trauma: Patient-Centered and Trauma-Cognizant Management by Physical Therapists
Authors: Dunleavy Kim , Kubo Slowik Amy
Published: December 2011

Background and Purpose

Sexual violence has been identified as one of the most common predictors of posttraumatic stress disorder (PTSD). This case report describes the emergence of delayed PTSD symptoms, disclosure of history of sexual trauma, and the influence of re-experiencing, avoidance, and hyperarousal symptoms on physical therapy treatment.

Case Description

A 60-year-old woman was seen for treatment of low back pain. Discussion of a discord between fear of falling and no balance impairments led to disclosure of sexual assault by a physician at 19 years of age. The patient's PTSD symptoms emerged after 10 weeks of physical therapy. The physical therapists monitored somatic responses and body language closely and modified and planned treatment techniques to avoid PTSD triggers and limit hyperarousal. Collaborative communication approaches included reinforcement of cognitive-behavioral strategies introduced by her psychotherapists.

Outcomes

Trauma-cognizant approaches supported the patient's efforts to manage PTSD symptoms sufficiently to tolerate physical therapy and participate in a back care class. Nonlinear psychological healing is illustrated.

Discussion

Symptoms of PTSD may emerge during physical therapy treatment, and patient-sensitive responses to disclosure are important. The trauma-cognizant approach (2-way communication, patient-centered management, and integration of psychological elements into clinical decision making) helped identify and respond to triggers. The physical therapists reinforced cognitive-behavioral strategies introduced by psychotherapists to manage PTSD symptoms. Patient-centered care with further refinement to a trauma-cognizant approach may play an important role in assisting patients with PTSD or a history of sexual trauma to manage symptoms while addressing rehabilitation needs.
Facilitators of and Barriers to Physical Activity in Retirement Communities: Experiences of Older Women in Urban Areas
Authors: Bjornsdottir Gudfinna , Arnadottir Solveig A. , Halldorsdottir Sigridur
Published: December 2011

Background

Older people are being encouraged to be physically active for as long as possible as a preventive measure against disease and functional decline. It remains, however, uncertain how living in a retirement community affects physical activity (PA).

Objectives

This study was conducted to understand the PA experiences of older women living in retirement communities and what they experience as facilitators of and barriers to PA.

Design

The study was qualitative and guided by the Vancouver School of doing phenomenology, a unique blend of phenomenology, hermeneutics, and constructivism.

Method

Participants were 10 women, aged from 72 to 97 years (mean=84 years). In-depth interviews were conducted, recorded, transcribed, and thematically analyzed.

Results

A model was constructed with 3 main themes: (1) the women themselves, including their experienced health condition, individual aspects of functioning, and various personal factors; (2) the physical environment; and (3) the social environment. These main themes all include subthemes of experienced influences on PA, such as health, design of housing and environment, and local culture. These influences could both facilitate and hinder PA, depending on the context. The facilitating effects of good outdoor areas, accessible physical training facilities, a familiar neighborhood, and finding joy in PA were clear in the study. The barriers included worsening health, a colder climate with ice and wind, and lack of a PA culture within the retirement community.

Conclusions

An older woman's residence may strongly influence her ability and motivation to be physically active. Physical therapists should acquaint themselves with the facilitators of and barriers to PA of women within retirement communities and use that knowledge to influence the physical and social environment and to target PA interventions to the women themselves.
Development of Web-Based Transit Trip-Planning System Based on Service-Oriented Architecture
Authors: Sun Daniel (Jian) , Peng Zhong-Ren , Shan Xiaofang , Chen Weiya , Zeng Xiaoqing
Published: December 2011

The majority of transit trip planners exist as proprietary systems based on particular vendor products. With the incorporation of more functional components, system maintenance and regular transit information updates become burdensome tasks for transit agencies. In addition, the proprietary nature of the systems makes it difficult to take advantage of the rapid advancement of geospatial information and web technologies. The authors proposed an open and interoperable transit trip-planning system based on a service-oriented architecture, with the principle of reusing the existing modular resources, while providing user-friendly interfaces for expansion of functionality. The objective was to integrate geospatial services available online (such as Google Maps), open-source geospatial database technologies, and path-finding algorithms in a loosely coupled manner. The proposed system was developed with spatial and temporal transit data from Waukesha Metro Transit in Wisconsin. Research results were validated by comparing outputs from the existing South-East Wisconsin Transit Trip Planner and route schedule matching. Comparison results showed that the new service-oriented architecture provided a flexible, efficient mechanism for transit-trip planners. The architecture took advantage of rapidly changing online geospatial services, yet maintained the core functions of itinerary search that may be unique to each transit agency.
Peer-to-Peer Carsharing
Authors: Hampshire Robert C. , Gaites Craig
Published: December 2011

Many studies show that carsharing reduces transportation costs for a large segment of the population. Carsharing also reduces the number of private vehicles on the road because carshare members do not purchase their own cars. However, the traditional carsharing business model is difficult to scale geographically to neighborhoods with lower population densities because the operator must bear the upfront fixed cost of purchasing or leasing the vehicles in the fleet. In contrast to traditional carsharing, peer-to-peer (P2P) carsharing allows car owners to convert their personal vehicles into shared cars that can be rented to other drivers on a short-term basis. This model helps to improve the situation in which most privately owned vehicles sit idle more than 90% of the day. P2P carsharing alleviates upfront costs and thus is more economically consistent with lower-density neighborhoods than is traditional carsharing. As a result, P2P carsharing provides greater potential for car accessibility than traditional carsharing does. Several new service companies are dedicated to P2P carsharing. A methodology was developed to assess the market feasibility of P2P carsharing. The methodology was applied to develop a case study of P2P carsharing in Pittsburgh, Pennsylvania. The market for P2P carsharing was found to be economically viable. However, uncertain and fragmented public policy and car insurance regimes threatened the growth and investment in P2P carsharing.
Pavement Preservation
Authors: Chan Susanne , Lane Becca , Kazmierowski Tom , Lee Warren
Published: December 2011

The Ministry of Transportation of Ontario, Canada (MTO), is dedicated to maintaining quality roadways in a sustainable manner. In recent years, MTO has implemented pavement preservation strategies to maximize cost savings in repair operations and to maintain pavement condition. Pavement preservation treatments are considered sustainable because they improve pavement quality and durability and extend pavement service life, while reducing energy consumption and greenhouse gas (GHG) emissions. Pavement preservation is a proactive, planned strategy that extends the life of the pavement and provides a cost-effective solution for pavement management. This paper outlines the various pavement preservation treatments used by MTO to achieve sustainability. These preservation treatments include crack sealing, slurry seal, microsurfacing, chip seal, ultrathin bonded friction course, fiber-modified chip seal, hot-mix patching, and hot in-place recycling. With use of the PaLATE software, pavement sustainability is quantified by comparing the energy consumption and GHG emissions generated for various pavement preservation strategies against typical rehabilitation and reconstruction treatments. This paper presents the benefits of pavement preservation by considering the service life of each treatment and calculating the associated energy consumption and GHG emissions per service year. Results indicate that pavement preservation strategies provide a significant reduction in energy use and GHG emissions when compared with traditional rehabilitation and reconstruction treatments. Although pavement preservation has been proved to be a cost-effective solution, there are numerous challenges and barriers to overcome. Some of the challenges and solutions as well as the strategies to promote pavement preservation for sustainability are presented in the paper.
Pavement Preservation on High-Traffic-Volume Roadways
Authors: Smith Kelly L. , Peshkin David G.
Published: December 2011

Extending the life of roadway pavements with the timely use of preservation techniques has been an important strategy for highway agencies for many years. However, although preservation strategies for low- to moderate-volume roadways are widely accepted, are fairly commonplace, and have generally been successful, implementation of those same strategies on high-traffic-volume roadways involves greater challenges. The SHRP 2 Project R26 was performed to examine pavement preservation strategies for high-traffic-volume applications and to develop guidance on which preservation treatments are appropriate under what circumstances. In this project the state-of-the-practice for preservation approaches for high-traffic-volume roadways was identified through a national and international literature search and a detailed survey of highway agencies and other pertinent organizations. This project also involved developing a set of best practices and guidelines for selecting preservation treatments at the project level on the basis of careful and complete assessments of factors such as traffic volume, pavement condition, climatic condition, costs, expected performance, and work zone requirements. This paper presents findings from the highway agency survey and discusses how those results were used in conjunction with the literature review results to develop the key deliverable for the study: the stand-alone document Guidelines for the Preservation of High-Traffic-Volume Roadways.
Optimum Time for Application of Slurry Seal to Asphalt Concrete Pavements
Authors: Hajj Elie Y. , Loria Luis , Sebaaly Peter E. , Borroel Corina M. , Leiva Paulina
Published: December 2011

This study evaluated the field performance of asphalt pavements with and without slurry seal applications, developed performance models for asphalt pavements without slurry seals and asphalt pavements receiving slurry seals at various times following construction, and identified the optimum time for applying slurry seals on asphalt pavements in the Washoe County, Nevada, region. This determination was achieved by evaluating the long-term pavement performance data collected with the MicroPAVER system for the past 15 years and the cost-effectiveness of slurry seals applied to new and existing flexible pavements at Years 0, 1, 3, 5, 7, and 9 after construction. This study found that applying slurry seal immediately after or 1 year after construction of the asphalt layer is not effective in regard to the benefit to users and the benefit–cost ratio for the agency. The optimum time of applying slurry seal depended on the type of construction activity. For newly constructed pavements, the optimum time to apply slurry seal was 3 years after construction. For pavements subjected to overlays, the optimum time to apply slurry seal was between 3 and 5 years after construction. However, for uniformity purposes, it was recommended that the agency apply slurry seal 3 years after construction of the asphalt layer for both new and overlay constructions.
Evaluation of Potential Long-Term Durability of Joints Cut with Early-Entry Saws on Rigid Pavements
Authors: Krstulovich James M. , Van Dam Thomas , Smith Kurt D. , Gawedzinski Mark
Published: December 2011

Early-entry sawing is an attractive operation to expedite the construction of jointed concrete pavements; however, there are some concerns that early-entry sawing may compromise the pavement's long-term performance. The Illinois Department of Transportation initiated this study as an initial effort to investigate the durability of joints sawed by using early-entry sawing. Joint performance as a function of saw-cut depth and timing was also considered. The study was integrated into an active construction project along Illinois Route 59 in Plainfield. During construction, paving and sawing operations were observed and documented; of particular interest were the sawing operations, during which signs of surface scarring, joint raveling, and slab edge breakouts were recorded and the extent of sawing-related damage was subjectively assessed. In addition to general observations, climatic conditions were monitored, as was pavement temperature from time of paving onward. Ambient climate conditions, portland cement concrete mixture, and slab temperature data were used to perform a HIPERPAV analysis to assess the potential for early-age cracking. Compressive strength cylinders were also cast and tested at 3, 7, and 28 days. In addition, cores were retrieved from joints throughout the test section and a battery of durability tests—including petrographic analysis, freeze–thaw testing, and resistance to salt scaling—was conducted. Overall observations from the field construction and findings from the laboratory testing indicate that the use of early-entry sawing is viable and that joint durability is not compromised.
Scheduling under Uncertainty for Single-Hub Intermodal Freight System
Authors: Marković Nikola , Schonfeld Paul
Published: December 2011

This paper examines the optimization of an intermodal system with freight transfers at a single hub by determining when departures should be scheduled on outbound routes, given information about the probabilistic arrivals of vehicles on inbound routes. The intermodal system is modeled with stochastic programming, and the schedule of outbound vehicles is optimized with a genetic algorithm. The model is designed to minimize the expected total cost of operating an intermodal system while considering all capacity constraints arising in the real world. This model allows the system performance to be computed numerically, without the approximations of alternative methods such as simulation. Although the model can be applied to the most general case, the model seems to be especially suitable for analyzing systems with a relatively small number of arrivals on inbound routes. In particular, the model can be successfully applied to situations where statistical or queuing analyses are not applicable because of the small number of events (vehicle arrivals). The authors specifically analyze an intermodal system consisting of multiple inbound truck routes and multiple outbound airline routes. However, the mathematical model developed in this paper is applicable to other combinations of transportation modes.
Determining Fair Share Regional Targets for Reduction of Greenhouse Gas Emissions from Transportation and Land Use
Authors: Barbour Elisa , Newmark Gregory L. , Deakin Elizabeth A.
Published: December 2011

California passed landmark planning legislation, Senate Bill (S.B.) 375, in 2008, calling on the state's urban regions to reduce greenhouse gas emissions through more efficient transportation and land use. During 2010, the California Air Resources Board worked with the state's 18 metropolitan planning organizations to define and adopt performance targets for emissions reductions in each region according to S.B. 375. This target-setting process represents the first systematic effort by a U.S. state to assess the impacts of existing regional transportation and land use plans on greenhouse gas emissions and to adopt specific, realizable alternative scenarios in furtherance of state climate policy goals. This paper considers the technical and political challenges of defining the performance targets across regions and agencies with different conditions and capabilities. The paper depicts the S.B. 375 target-setting process as inherently political and collaborative. The paper also presents analysis from the target-setting documentation. Scenarios modeled to achieve emissions reductions in California's largest urban regions indicate that the greatest benefits are possible through combining pricing and land use strategies. The findings will inform policy makers in other states who also seek to address climate change systematically through coordinated transportation and land use strategies.
Creating Liveable Neighborhoods through Context-Sensitive Multimodal Road Planning
Authors: Beukes E. , Vanderschuren M. , Zuidgeest M. , Brussel M.
Published: December 2011

Improving mobility is seen as key to facilitating the economic uplift of the urban poor. In South Africa, the majority of the urban poor live on the periphery of cities. They travel long distances at great cost to go to work and school and are dependent on public transport and nonmotorized transport (NMT) (walking or cycling) for their travel needs. Despite legislation and policies that emphasize the role of public transport and NMT, road planning practice in South Africa continues to be automobile-centric. The needs of other road users are often overlooked, even in areas where they are in the majority. This paper describes the use of spatial multicriteria evaluation to rank modes according to their suitability at points along a defined route by using land use, socioeconomic, environmental, and transportation factors in combination to describe the contextual setting of the route. A case study conducted along an existing arterial route in Cape Town, South Africa, is used to demonstrate the method and the results of the analysis. The research finds that contextual regimes can be identified along the route and shows that each of these regimes has differing implications for the various modes that pass through these corridors.
Integrating Travel Demand Model and Benefit–Cost Analysis for Evaluation of New Capacity Highway Projects
Authors: An Meiwu , Casper Craig
Published: December 2011

This study presents a methodology for estimating the benefit–cost ratio for transportation projects by using a regional travel demand model and benefit–cost analysis. The benefit–cost ratio can provide an objective measure with which decision makers can quantitatively evaluate the regional benefits and costs of each proposed transportation project under certain assumptions. This methodology shows the impact of one project on the entire regional transportation network. The key to this methodology is use of the total savings in vehicle hours traveled (VHT) resulting from each proposed project, converted into dollar benefits. The total VHT is estimated with congested travel time and trips instead of a simple summation of each link's VHT. A second key aspect of this methodology is estimating the economic development benefits of the proposed transportation investments. For this process, the Pikes Peak Area Council of Governments used the Transportation Economic Development Impact System (TREDIS) web-based software. The input that TREDIS requires for new capacity transportation projects is total VHT or vehicle miles traveled (VMT) before a project and total VHT or VMT after the project, by trip purpose and travel mode. TREDIS offers default values such as economic value factors for driver and occupant time-saving benefits (dollars per VHT or VMT) and the vehicle cost factor for vehicle cost savings (dollars per VHT or VMT). The case study suggests that the proposed approach can be useful and effective in assessing regional transportation projects by considering their economic impacts.
Resource Guide for Enhancing the Incorporation of Safety into the Regional Planning Process
Authors: Miller John S. , Garber Nicholas J. , Kamatu Josephine N.
Published: December 2011

One way to reduce the annual U.S. $230 billion societal cost of motor vehicle crashes is to incorporate safety directly into the regional long-range transportation planning process. A survey of Virginia regional planning agencies revealed both a healthy interest in such integration and obstacles to the integration of safety and planning. Thus, merely exhorting regional agencies to emphasize safety is unlikely to affect planning practice. This paper reports on the creation of a resource guide that addresses the obstacles by providing numerous, specific examples implementable at the level of a regional planner with limited staff. For instance, in one rural plan where several projects entail widening substandard high-speed travel lanes, the guide shows how to estimate expected crash reductions so that projects with the greatest safety impact are identified. A contrasting example shows how to reduce urban crashes through removing a vehicle travel lane, adding a bicycle path, and managing access. Thus, the guide reflects the diverse opportunities for linking safety and planning. Other topics in the guide are crash data analysis, alignment of plan goals with specific programs, use of performance measures to prioritize alternatives, and innovative funding sources for safety-related improvements—all based on real data or plans such as monitoring the impact of a speed limit change on crashes while accounting for random variation. Recognizing that there is no shortage of planning-related literature, the guide acknowledges, but does not duplicate, the long-range regional planning process.
Postprocessing Procedures for Person-Based Global Positioning System Data Collected in the French National Travel Survey 2007–2008
Authors: Marchal Philippe , Madre Jean-Loup , Yuan Shuning
Published: December 2011

A challenge in the postprocessing of data for a passive Global Positioning System–based travel survey, which constitutes the essence of this paper, is the development of a series of methods for automatically restoring continuous sequences, both in space and in time. Thus trips and activities occurring during the survey period should be identified in chronological order and should respect conventional definitions. On the basis of previous research results and a combination of the experience from the French National Travel Survey 2007–2008 and the Personal Mobility Survey in Lille, France, a series of methods has been developed and applied: (a) filtering invalid data, (b) cutting the data chains into “moving” and “stopping” segments, (c) estimating missing data, (d) assuming mode choice, (e) grouping stop points into visited locations, (f) identifying the type of visited points, (g) map-matching, and (h) connecting segments to trips. To use the maximum available information and guarantee the quality of the results, some feedback between the methods is implemented within the algorithm. The resulting processing system is ready for use in other applications.
Non-Lane-Based Car-Following Model with Visual Angle Information
Authors: Jin Sheng , Wang Dian-Hai , Yang Xi-Rui
Published: December 2011

Car-following theory is of significance in microscopic traffic flow theory. The key assumption of current car-following theory is that vehicles travel in the middle of a single lane. However, this assumption is unrealistic and cannot describe driving behavior in a complex traffic environment. When the lateral separation characteristics between the follower and the leader are taken into account, the time-to-collision equation is modified with visual angle information and introduced into the General Motors model. A non-lane-based model of car following was developed; it uses time to collision and is based on the stimulus–response framework. The proposed model was investigated with simulations conducted under several driving scenarios. The model could describe local and asymptotic stabilities, lateral movement, and the effect of neighboring vehicles. Results implied that this staggered car-following model incorporating lateral separation greatly enhanced the realism of car-following behavior.