bluuebunny/crossref_metadata_2025_split huggingface dataset:
Development and Application of a Fully-coupled Two-dimensional Finite Element Approach to Deformation and Pressure Diffusion Around a Borehole
Authors: Cheng H. , Dusseault M.B. 
Published: July 2010

Abstract
The fully-coupled deformation and diffusion behaviour around a boreholedrilled in a fluid-saturated poroelastic medium are modelled using atwo-dimensional finite element method. A variational principle equivalent tothe governing equations in the theory of poroelasticity is derived. Thevariational principle used here to achieve a full coupling is notconventionally employed in porous medium mechanics, therefore verificationprocedures were implemented.
The distribution and the history of effective stresses and pore pressurearound the borehole, valuable factors for evaluation of borehole stability andsolids production potential, are evaluated in hydrostatic and non-hydrostaticstress fields, and under different wellbore pressures. For typical cases thatcorrespond to oil field conditions, significant differences are found betweenthe fully-coupled solution and the uncoupled solution.

Introduction
The basic equations for coupling elastic deformation with pore pressure forporous media subjected to transient fluid flow were first established by Biotin 1941. There have since been numerous restatements given, and Rice and Cleary provide an particularly elegant reformulation of Biot theory byredefining the material constants. The theory of poroelasticity not onlypredicts quantitative differences from uncoupled flow-deformation theory, italso predicts phenomena such as the Mandel-Cryer effect, which are neitherintuitive nor revealed by the uncoupled theories. It has become the preferredapproach in many geomechanical applications, but because of the governingequations' complexity, analytical or closed-form solutions are available onlyfor cases of simple geometry and boundary conditions. For example, a recentdevelopment by Wang and Dusseault provides a solution for fullyporoelastic coupling in an axisymmetric plane strain borehole subjected toinjection or withdrawal.
The complexities of the governing equations coupling deformation withdiffusion, combined with the strongly non-linear behaviour of geomaterials, naturally increase the importance and popularity of numerical approaches. The Finite Element Method (FEM) is the most widely used procedure for numericallyapproximating the theory of poroelasticity. In cases involving coupleddeformation-diffusion, there are two formulations of FEM commonly employed tosolve boundary value problems.
The Effect of Shear Failure on the Cyclic Steam Process and New Pseudo Functions for Reservoir Simulation
Authors: Ito Y. , Settari A. , Jha K. 
Published: July 2010

Abstract
The steam stimulation process is a proven, commercially viable recoveryprocess in oil sand reservoirs. However, an understanding of the recoverymechanism is far from complete. Recent studies of the geotechnical aspects oftar sands point to the importance of shear failure created by pore pressureincrease on fluid flow in the reservoir during steam injection. The changes inmass and heat transport properties in the heterogeneously deformed failure zonehave been shown to be important factors for the recovery mechanism. This paperdescribes the theoretical and practical aspects of representing the shearfailure zone in reservoir simulation, by the means of pseudo relativepermeability functions.
Relative permeability hysteresis is commonly used in the simulation of thesteam stimulation process, but its mechanism is not clear. The paper reviewsthe existing methods for treating hysteresis and gives the theory for thepseudo relative permeabilities caused by heterogeneously failed media. The newfunctions are derived by considering the shear failure phenomenon. A new set ofstress-dependent pseudo relative permeabilities is proposed and a practicalmethod for the use of the pseudo functions (including hysteresis) in areservoir simulator is given. The method applies to injection as well asproduction cycles. Its effect on simulating the cyclic steam process is givenin examples and shows that the hysteresis should be stress-dependent ratherthan saturation-dependent.

Introduction
When the same set of water-oil relative permeability data is used tosimulate the injection and production periods of a cyclic steam stimulationprocess in tar sands or a heavy oil reservoir, the simulated water-oil ratiosare usually much greater than those observed in the field. To achieve a bettermatch of field data in the reservoir simulator, a higher relative permeabilityto water is used during the injection period than that used during theproduction period. The use of this technique in simulating a cyclic steamstimulation process is reported in a number of papers. It is based on theresults of laboratory studies on the hysteresis phenomenon of relativepermeability which will be briefly reviewed.
Production Problems in the Steam-stimulated Shaley Oil Sands of the Cold Lake Reservoir: Cause and Possible Solutions
Authors: Chakrabarty T. , Longo J.M. 
Published: July 2010

Abstract
The highly viscous bitumen from the Cold Lake reservoir in Alberta isproduced by the Cyclic Steam Stimulation (CSS) process. The clean oil sands ofthe Cold Lake reservoir generally produce well, but the shaley oil sands withimbedded clasts have experienced lower bitumen production and lower steaminjectivity.
This paper presents laboratory and field data that support the hypothesisthat the minerals in the clasts play a role in the production problems of theshaley oil sands. Laboratory tests reveal that clasts in the shaley oil sandshave an abundance of carbonate minerals such as siderite (iron carbonate) andaluminosilicate minerals such as kaolinite and feldspar. Laboratory studiesunder steam stimulation conditions show that the mineral reactions betweencarbonates and aluminosilicates can generate formation damaging products suchas swelling clay and carbon dioxide. Swelling clay can damage the formation byplugging the pore throats, whereas carbon dioxide can lead to near-wellborescaling. Calcium carbonate scales have been observed in downhole pumps andliners in Cold Lake wells. The field bitumen production appears to be inverselycorrelated with the carbonate content of the clasts. The field bitumenproduction is also inversely correlated with the amount of carbon dioxidegenerated in the laboratory by hydrothermal reactions of clasts. The paperdescribes the application of portable X-ray fluorescence (XRF) andnear-infrared instruments for rapid, nondestructive identification of reactiveminerals in cores, and of photoelectric absorption (Pe) logs for identifyingshaley oil sands with reactive minerals. It proposes diagnostic tests toidentify the extent and type of damage in a producing well. Finally, itdiscusses several potential methods for formation damage remediation andprevention.

Introduction
Cold Lake reservoir in northeastern Alberta has a vast resource base of oilsands. The bitumen in the oil sands has a viscosity of about 100,000 cp atreservoir temperature. Imperial Oil Resources Limited is using the Cyclic Steam Stimulation (CSS) process to recover the bitumen. The wells are drilleddirectionally from one surface location and there are twenty wells in one pad. In one cycle, steam is injected over a period of 30 to 40 days, and a hotbitumen and water mixture is produced over several months. Each well goesthrough several cycles of injection and production until steam injectionbecomes uneconomic.
Concentric Coiled Tubing Application for Sand Cleanouts in Horizontal Wells
Authors: Falk K. , Fraser B. 
Published: July 2010

Abstract
The evolution of coiled tubing technology has brought many unique wellservice solutions to the oil and gas industry. Concentric Coiled Tubing (CCT)is a recent development which has opened the door to a whole range of new wellservicing capabilities. One of these techniques incorporates concentric coiledtubing equipment with a patented jet pump tool (SandVacSM, US patentnumber 5,033,545) specifically for the purpose of cleaning sand out of lowpressure horizontal wells. This paper will discuss cleanout issues and how the SandVacSM process provides an improved solution to cleaning in lowpressure, horizontal wells. To summarize, a review and discussion of the firstfive Sand-VacSM field applications will be given.

Introduction
Sand production is often a serious problem for heavy oil producers. Whensuspended in the produced flow, sand can cause destructive abrasion of pumpingequipment. On surface, the operator must deal with separation, handling andfinally, disposal of potentially large quantities of contaminated fines. Themost serious consequence of sand production however, is when deposition occursin the completion. Settled quantities of sand in the completion will impedefluid flow and therefore impede production. This problem is compounded by thefact that heavy oil producers are turning to horizontal well technology tomaximize production. Compared with vertical wells, horizontal wells have thefollowing characteristics:A longer interface for sand-inflowPerpendicular orientation of fluid flow and settling velocity vectorsSlight horizontal trajectory undulations-resulting in "troughing"
Each of these conditions has a significant effect on the amount of sandaccumulation in the completion.

Sand Control
A number of methods have been used to try to prevent sand inflow. Totalexclusion techniques employ a formation barrier designed to prevent any solidsfrom entering the completion. This technique is often very expensive and canresult in severe skin effects at the barrier(l). A more cost effectiveinstallation uses a "partial exclusion" approach. Usually, this takes the formof a liner in which specifically sized slots have been cut. The liner thenpreserves the hole integrity while the slots allow oil inflow.
An Experimental Investigation of Convergent Flow To Horizontal Wells
Authors: Suprunowicz R. , Butler R.M. , Ford C.O.K. , Kry S.F. 
Published: July 2010

Abstract
If the problem of fluid flow in a reservoir toward a well cannot beapproximated as a two-dimensional one, the analytical treatment becomes verydifficult. This is especially true when horizontal wells are involved and theend-effect cannot be neglected.
There are, in the literature, mathematical expressions to calculateproductivity of horizontal wells for various geometric configurations and manyof these include the effect of flow convergence. Some of them appear to besignificantly in error.
The paper describes experiments with an electrolytic model. This approachuses the analogy between the flow of fluid particles, driven by fluidpotential, in a porous medium and movement of ions, driven by electricalpotential, in an electrolyte. A simple and low-cost experimental setup permitsthe testing of various theoretical equations and the results are presented.

Introduction
In many cases the flow of fluids in a homogeneous reservoir toward a well, vertical or horizontal, can be analyzed simply when the problem istwo-dimensional. In some situations this approach may be sufficient; but when, because of more complicated geometry, the effect of convergence toward the tipof a well (as, for example, in the case of a vertical well partiallypenetrating a liquid- bearing porous matrix layer) has to be taken intoaccount, the difficulties of establishing the flow pattern and, consequently, calculations of the well productivity, may be significant.
A common simplification is the assumption of the uniform flux along theactive well length. But this approach, as pointed out by Muskat(l), does notgive the correct results, even for the relatively simple case of a partiallypenetrating vertical well and steady-state flow.
The situation becomes more difficult for horizontal wells of finite lengthdraining bounded volumes. There is usually a problem of convergent flow towarda well in a plane perpendicular to the well's axis, but on top of this there isa three-dimensional convergence toward the tips of the well. Probably in somesituations when, for example, the well is very long and draining a thin layerand narrow pattern, this additional convergence can be neglected.
Chronic Administration of the Glucagon-Like Peptide-1 Analog, Liraglutide, Delays the Onset of Diabetes and Lowers Triglycerides in UCD-T2DM Rats
Authors: Cummings Bethany P. , Stanhope Kimber L. , Graham James L. , Baskin Denis G. , Griffen Steven C. , Nilsson Cecilia , Sams Anette , Knudsen Lotte B. , Raun Kirsten , Havel Peter J. 
Published: July 2010

OBJECTIVE
The efficacy of liraglutide, a human glucagon-like peptide-1 (GLP-1) analog, to prevent or delay diabetes in UCD-T2DM rats, a model of polygenic obese type 2 diabetes, was investigated.

RESEARCH DESIGN AND METHODS
At 2 months of age, male rats were divided into three groups: control, food-restricted, and liraglutide. Animals received liraglutide (0.2 mg/kg s.c.) or vehicle injections twice daily. Restricted rats were food restricted to equalize body weights to liraglutide-treated rats. Half of the animals were followed until diabetes onset, whereas the other half of the animals were killed at 6.5 months of age for tissue collection.

RESULTS
Before diabetes onset energy intake, body weight, adiposity, and liver triglyceride content were higher in control animals compared with restricted and liraglutide-treated rats. Energy-restricted animals had lower food intake than liraglutide-treated animals to maintain the same body weights, suggesting that liraglutide increases energy expenditure. Liraglutide treatment delayed diabetes onset by 4.1 ± 0.8 months compared with control (P &lt; 0.0001) and by 1.3 ± 0.8 months compared with restricted animals (P &lt; 0.05). Up to 6 months of age, energy restriction and liraglutide treatment lowered fasting plasma glucose and A1C concentrations compared with control animals. In contrast, liraglutide-treated animals exhibited lower fasting plasma insulin, glucagon, and triglycerides compared with both control and restricted animals. Furthermore, energy-restricted and liraglutide-treated animals exhibited more normal islet morphology.

CONCLUSIONS
Liraglutide treatment delays the development of diabetes in UCD-T2DM rats by reducing energy intake and body weight, and by improving insulin sensitivity, improving lipid profiles, and maintaining islet morphology.
Large Copy-Number Variations Are Enriched in Cases With Moderate to Extreme Obesity
Authors: Wang Kai , Li Wei-Dong , Glessner Joseph T. , Grant Struan F.A. , Hakonarson Hakon , Price R. Arlen 
Published: July 2010

OBJECTIVE
Obesity is an increasingly common disorder that predisposes to several medical conditions, including type 2 diabetes. We investigated whether large and rare copy-number variations (CNVs) differentiate moderate to extreme obesity from never-overweight control subjects.

RESEARCH DESIGN AND METHODS
Using single nucleotide polymorphism (SNP) arrays, we performed a genome-wide CNV survey on 430 obese case subjects (BMI &gt;35 kg/m2) and 379 never-overweight control subjects (BMI &lt;25 kg/m2). All subjects were of European ancestry and were genotyped on the Illumina HumanHap550 arrays with ∼550,000 SNP markers. The CNV calls were generated by PennCNV software.

RESULTS
CNVs &gt;1 Mb were found to be overrepresented in case versus control subjects (odds ratio [OR] = 1.5 [95% CI 0.5–5]), and CNVs &gt;2 Mb were present in 1.3% of the case subjects but were absent in control subjects (OR = infinity [95% CI 1.2–infinity]). When focusing on rare deletions that disrupt genes, even more pronounced effect sizes are observed (OR = 2.7 [95% CI 0.5–27.1] for CNVs &gt;1 Mb). Interestingly, obese case subjects who carry these large CNVs have moderately high BMI and do not appear to be extreme cases. Several CNVs disrupt known candidate genes for obesity, such as a 3.3-Mb deletion disrupting NAP1L5 and a 2.1-Mb deletion disrupting UCP1 and IL15.

CONCLUSIONS
Our results suggest that large CNVs, especially rare deletions, confer risk of obesity in patients with moderate obesity and that genes impacted by large CNVs represent intriguing candidates for obesity that warrant further study.
Fetal Exposure to Maternal Type 1 Diabetes Is Associated With Renal Dysfunction at Adult Age
Authors: Khalil Charbel Abi , Travert Florence , Fetita Sabrina , Rouzet François , Porcher Raphael , Riveline Jean-Pierre , Hadjadj Samy , Larger Etienne , Roussel Ronan , Vexiau Patrick , Le Guludec Dominique , Gautier Jean-François , Marre Michel 
Published: July 2010

OBJECTIVE
In animal studies, hyperglycemia during fetal development reduces nephron numbers. We tested whether this observation translates into renal dysfunction in humans by studying renal functional reserve in adult offspring exposed in utero to maternal type 1 diabetes.

RESEARCH DESIGN AND METHODS
We compared 19 nondiabetic offspring of type 1 diabetic mothers with 18 offspring of type 1 diabetic fathers (control subjects). Glomerular filtration rate (51Cr-EDTA clearance), effective renal plasma flow (123I-hippurate clearance), mean arterial pressure, and renal vascular resistances were measured at baseline and during amino acid infusion, which mobilizes renal functional reserve.

RESULTS
Offspring of type 1 diabetic mothers were similar to control subjects for age (median 27, range 18–41, years), sex, BMI (23.1 ± 3.7 kg/m2), and birth weight (3,288 ± 550 vs. 3,440 ± 489 g). During amino acid infusion, glomerular filtration rate and effective renal plasma flow increased less in offspring of type 1 diabetic mothers than in control subjects: from 103 ± 14 to 111 ± 17 ml/min (8 ± 13%) vs. from 108 ± 17 to 128 ± 23 ml/min (19 ± 7%, P = 0.009) and from 509 ± 58 to 536 ± 80 ml/min (5 ± 9%) vs. from 536 ± 114 to 620 ± 140 ml/min (16 ± 11%, P = 0.0035). Mean arterial pressure and renal vascular resistances declined less than in control subjects: 2 ± 5 vs. −2 ± 3% (P = 0.019) and 3 ± 9 vs. −14 ± 8% (P = 0.001).

CONCLUSIONS
Reduced functional reserve may reflect a reduced number of nephrons undergoing individual hyperfiltration. If so, offspring of type 1 diabetic mothers may be predisposed to glomerular and vascular diseases.
Procyanidin B1 Purified from Cinnamomi Cortex Suppresses Hepatitis C Virus Replication
Authors: Li Shenwei , Kodama Eiichi N , Inoue Yuuki , Tani Hideki , Matsuura Yoshiharu , Zhang Jing , Tanaka Takashi , Hattori Toshio 
Published: July 2010

Background: A combination of pegylated interferon and ribavirin is the current standard therapy for hepatitis C virus (HCV) infection, but this combination provides relatively low efficacy, especially in some patients with HCV genotype 1 infection; therefore, the development of novel therapeutic agents is required for further improvement in the treatment of chronic HCV infection. Methods: HCV pseudotype and subgenomic replicon assays were used in this study. The interaction of compounds with HCV receptors was examined using flow cytometry. Intracellular RNA levels were determined by semi-quantitative reverse transcriptase PCR. Results: Procyanidin B1 (PB1), a dimer of (−)-epicatechin and (+)-catechin, purified from Cinnamomi cortex, inhibits infection by vesicular stomatitis virus and HCV pseudotype virus in Huh-7 cells, with 50% effective concentrations of 29 and 15 μM, respectively. No inhibitory effects were observed in each component of PB1. We found that PB1 does not interfere with viral entry or receptor expression, but inhibits HCV RNA synthesis in a dose-dependent manner. Conclusions: These results indicate that PB1 suppresses HCV RNA synthesis, possibly as a HCV RNA polymerase inhibitor. Our results might contribute towards the development of more effective inhibitors for HCV infection from natural plants.
A Novel TNF Receptor-Associated Factor 6 Binding Domain Mediates NF-κB Signaling by the Common Cytokine Receptor β Subunit
Authors: Meads Mark B. , Li Zhi-Wei , Dalton William S. 
Published: July 2010

Abstract
GM-CSF, IL-3, and IL-5 are proinflammatory cytokines that control the production and function of myeloid and lymphoid cells. Their receptors are composed of a ligand-specific α subunit and a shared common signal-transducing β subunit (β common receptor or GM-CSFR β [βc]). The pleiotropic nature of biologic outcomes mediated by βc and the presence of large, uncharacterized regions of its cytoplasmic domain suggest that much remains to be learned about its downstream signaling pathways. Although some previous work has attempted to link βc with NF-κB activation, a definitive mechanism that mediates this pathway has not been described and, to date, it has not been clear whether the receptor can directly activate NF-κB. We demonstrate that NF-κB activation by βc is dependent on TNFR-associated factor 6 (TRAF6) and that association of TRAF6 with βc requires a consensus-binding motif found in other molecules known to interact with TRAF6. Furthermore, point mutation of this motif abrogated the ability of βc to mediate NF-κB activation and reduced the viability of an IL-3–dependent hematopoietic cell line. Because this receptor plays a key role in hematopoiesis and the βc cytoplasmic domain identified in this work mediates hematopoietic cell viability, this new pathway is likely to contribute to immune cell biology. This work is significant because it is the first description of a TRAF6-dependent signaling pathway associated with a type I cytokine receptor. It also suggests that TRAF6, a mediator of TNFR and TLR signaling, may be a common signaling intermediate in diverse cytokine receptor systems.
Cbl-b−/− T Cells Demonstrate In Vivo Resistance to Regulatory T Cells but a Context-Dependent Resistance to TGF-β
Authors: Adams Catherine O. , Housley William J. , Bhowmick Sourojit , Cone Robert E. , Rajan Thiruchandurai V. , Forouhar Faripour , Clark Robert B. 
Published: July 2010

Abstract
Cbl-b is an E3 ubiquitin ligase that negatively regulates T cell activation. Cbl-b−/− mice develop spontaneous autoimmunity, and Cbl-b dysregulation has been described in both murine and human autoimmune diseases. Although the mechanisms underlying the development of autoimmunity in Cbl-b−/− mice are not yet clear, we have reported that Cbl-b−/− CD4+CD25− effector T cells (Teffs) are resistant to CD4+CD25+ regulatory T cell (Treg)-mediated suppression in vitro and have suggested that this may be an important mechanism in the development of autoimmunity. To confirm the relevance of this resistance to autoimmune disease, we now show that Cbl-b−/− Teffs are resistant to suppression by Tregs in vivo and that this involves a resistance of truly naive Cbl-b−/− Teffs. Additionally, we show that Cbl-b−/− Tregs are fully functional in vivo, further suggesting that the regulatory abnormalities in Cbl-b−/− mice are related to defects in Teff, not Treg, function. To characterize the relevance of TGF-β sensitivity in Treg resistance, we examined in vivo Th17 generation and report that Cbl-b−/− mice are able to mount a normal Th17 response in vivo. As Cbl-b−/− Teffs have been shown to be insensitive to the suppressive effects of TGF-β in other in vivo models, the present results suggest that Cbl-b−/− Teffs demonstrate a context-dependent sensitivity to TGF-β in vivo. Overall, our results suggest that resistance to Tregs may be a bona fide mechanism underlying autoimmunity and that Cbl-b−/− mice offer unique approaches for studying the interrelationships between Treg function, TGF-β–mediated responses, and the development of autoimmunity.