bluuebunny/crossref_metadata_2025_split huggingface dataset:
Case Histories - Implementation of New Liner Hanger Technology in South Central Venezuela Significantly Improves Operations in Complex Wells
Authors: Jimenez Cesar , Soto Simon , Leon Andrehny , Batocchio Marcelo , Marval Pedro , Schoener-Scott Martin 
Published: June 2009

Abstract
Liners hangers are used in deep drilling operations to eliminate the need to run full strings of casing. Unlike regular casings that are installed back to surface; liners will be terminated downhole at a hang-off point in the last casing. Deploying liner hangers can be very difficult, depending on the wellbore conditions. In many scenarios, the bottomhole assembly (BHA) must be rotated and/or reciprocated in order to set the BHA at the target depth, and conventional liner hanger systems often do not permit tool rotation due to the complex design. Liner-hanger failures ultimately can be the cause for losing the wellbore or a section of the wellbore, which in turn, will result in additional well construction costs to sidetrack and drill another section through the production zone.
This paper will discuss the use of an expandable liner hanger that has a less complicated design that withstands aggressive reaming as well as drilling to depth. This expandable system has no external moving parts such as slips, hydraulic-setting cylinders or separate liner-top packers, which are used in conventional liners. These attributes help mitigate the risks associated with the deployment exercise and the complexity of the completion.
PDVSA embraced this technology to help them optimize operations in their deep wells in which extreme environments, often close to 300°F, with deviations greater than 60 degrees and setting depths of more that 12,000 feet are encountered.
The benefits that have been gain by adopting this technology are:
Optimized capital expenditure Optimized rig-time efficiency (reduced NPT) Avoidance of costly redundant conditioning trips, hanger damage, and premature setting Elimination of external moving parts on hanger assembly (reduced complexity) Reduced rig time Improved reliability and fluid flow No slip damage to supporting casing
Case histories that compare the traditional and expandable liner hanger systems and verify the advantages stated above are presented.
Contracting Basics to Deliver Projects in Today's Supply Market
Authors: Benham Harry , Marijt Jaap 
Published: June 2009

Abstract
The world of project contracting in the oil and gas industry is in a state of flux, with an unprecedented high demand globally for contractor capability at a time of dwindling people and equipment resources. This is leading to seemingly ever-increasing costs, longer schedules and, all too often, inferior quality in the delivered project. The operators are struggling to find the best response to this variable and volatile situation, and a variety of outsourcing initiatives and contracting strategies are being tried and tested. However, we believe getting the basics right in contracting and procurement is now more important than ever.
In many parts of the world during the 80s and 90s, the capital contracting bias of the International Oil Companies (IOCs) and other operators moved towards large Engineering Procurement and Construction (EPC) contracts, with a lump sum reward mechanism. Large engineering firms, in an effort to enlarge their work scopes, started to provide this integrated EPC service, allowing the IOCs to outsource their labour intensive and detailed project management activities. These EPC-lump sum contracts gave contractors a strong incentive to perform well and, driven by fierce competition and a perceived relatively certain business environment, they assumed many of the risks associated with the project execution and delivery, with sharp focus on their own cost performance. The clients saw ‘competitive fixed prices’ being offered to deliver their projects, and this made contractor selection seem relatively straightforward.
With hindsight, the mid to longer-term consequences of this strategic approach were not foreseen or, at least, were underestimated. For IOCs, many assumed a (sometimes false) sense of cost certainty. Independent Project Analysis (IPA) insightfully stated that the lump sum price was generally perceived as a ceiling price, whereas in reality it was no better than a floor from which cost could, and inevitably often did, grow. This was made worse by the total lack of cost transparency to the IOCs, and hence their inability to meaningfully negotiate the commercial terms for repeat projects and standardisation, or to adequately assess variations and claims. EPC outsourcing also reduced the skill base of the IOCs, and thereby their ability to internally manage large projects and their interfaces at a component level.
Tracking Interwell Water Saturation in Pattern Flood Pilots in a Giant Gulf Oil field
Authors: Bhatti Zahid , Al Mansoori Yousof , El Sembawy Saber , Vahrenkamp Volker , Clerc Nicolas , Wilt Michael , Reeder Stacy 
Published: June 2009

Abstract
Peripheral water flooding has been the preferred pressure maintenance tool for many gulf carbonate reservoirs over the past 30 years. Due to uneven sweep and pressure distribution, this technique has given way to pattern floods in several gulf fields. As these new floods are established, it is important to understand the water saturation between wells to properly manage the sweep and recovery. In 2007, ADCO initiated water injection (WI) and WAG pilots to test the recovery strategy. The pilot employs advanced geophysical and modeling tools to measure formation properties at the wells and between wells; this paper discusses the WI pilot.
Among the novel techniques applied is the crosswell electromagnetic method, which measures the interwell resistivity distribution between observation wells at the pilots. Interwell resistivity data can be used to infer the water saturation distribution because of the sharply different electrical resistivity between injected water and oil bearing reservoir rock. By allowing an evaluation of the water distribution long before the injected fronts reach producers or observers, a better and more rapid understanding of the pilot arises from the crosswell electromagnetic technique.
In this paper, we briefly describe the pilot design, describe the detailed geological model and show results from the initial set of baseline and time lapse EM data sets from the water injection pilot. The images highlight the influence of background geological constraints on the flow.
Characterization of Hydraulically-Induced Fracture Network Using Treatment and Microseismic Data in a Tight-Gas Formation: A Geomechanical Approach
Authors: Xu Wenyue , Calvez Joël Le , Thiercelin Marc 
Published: June 2009

Abstract
Large amount of gas are being produced from unconventional tight-gas sand reservoirs (e.g., Cotton Valley Fm., Lobo Fm., Taylor Sand Fm. and, Wilcox Fm., etc.) and shale gas-bearing formations (e.g, Barnett, Fayetteville, Marcellus, Woodford, etc.). These plays are partly technology driven and partly economics driven. Modern well log evaluation techniques and completion methods are required to yield economic wells. In some cases microseismic monitoring campaigns are performed in these various low permeability environments to improve the understanding of the induced fracture network and to go beyond the simple assumption of a symmetric bi-wing fracture system.
To better characterize the induced fracture network, a semi-analytical pseudo 3-D geomechanical model was developed based on considerations of the conservation of injected fluid mass and the mechanic interactions both between fractures and injected fluid as well as among the fractures. The hydraulically stimulated volume is represented by a horizontally expanding ellipse containing a simplified fracture network consisting of two sets of vertical planar fractures perpendicular to one another. This model provides a mathematically-equivalent description of the process of hydraulic fracture propagation and the characteristics of the induced fractures.
Using microseismic datasets obtained during hydraulic treatments in several tight formations together with measured wellbore pressure and treatment parameters as the input, the modeling analysis yields information of the induced fracture network including fracture spacing and associated confining stress contrast. The results indicate a vertically contained developing fracture network with anisotropic spacing and moderate confining stress contrast. The fracture network extension toward the maximum horizontal stress is however limited. This information is then used as the input of the model to carry out forward simulations and provide detailed information of time-dependent fracture propagation including front location, fluid pressure, fracture width, induced porosity and permeability.
Application of Relative Location Technique from Surface Arrays to Microseismicity Induced by Shale Fracturing
Authors: Hulsey B. J. , Eisner Leo , Thornton Michael , Jurick Dana 
Published: June 2009

Abstract
A matched filter technique that uses cross-correlation and migration of the recorded waveforms has been successfully used to relatively locate microseismic events. In addition to producing consistent relative locations, the matched filter corrects for radiation pattern effects and near-surface structure. The relative locations produced using this methodology were compared with a proprietary, direct location method. The new results produce a solution set that reveals two parallel trends of microseismic events which are interpreted as 1500' long fracture zones approximately 100' wide. We observed asymmetric fracture growth and re-fracturing of the previously stimulated zones. Time correspondence of the observed evolution of seismic events with engineering pump curve data reveals approximate linear growth rates of several feet per minute and possible proppant placement along the induced fractures.
Verification of Flare Line Flows and Pipeline Deposit Measurement Using Non-Intrusive Radioisotope Technology
Authors: Hood Tony 
Published: June 2009

Introduction
Over the past forty years a range of services have been available to thepetrochemical and oil & gas industries to investigate the performance oftheir process systems. The various services offered involve the use ofradioactive sealed sources and radioactive unsealed sources, also known astracers, to provide a rapid and detailed on-line assessment of the performanceof process systems. These techniques effectively ‘look’ inside vesselsand pipes to identify their contents and measure their process conditions.
This paper focuses on a selected area of the technology as applied topipelines, but more specifically to Flow Rate Verification in Flare Lines and, more generally Pipeline Deposit Measurement in any pipeline.

Basics of Radioisotope Technology
There are four main types of radioactivity. These are alpha particles, betaparticles, neutrons, and gamma electromagnetic radiation. Alpha and Betaemissions have limited use in industrial applications, as they are very weaklypenetrating and thus cannot be detected through a steel wall (see Fig.1). Neutrons have a very specific use for diagnostic purposes and can beused to determine the presence and location of hydrogenous liquids within aprocess system. Electromagnetic gamma radiation is the most common formof radioactivity used for carrying out on-stream, non-intrusive investigationsas the radiation emitted is able to penetrate and pass through matter, such assteel and insulation, allowing its detection at the outside walls of a processsystem.
Gamma radioisotopes are used in two fundamental physical forms:Sealed sourcesUnsealed sources (otherwise known as tracers)
A sealed source consists of a small pellet of a radioisotope that is sealedwithin a steel case. Sealed sources can be used to scan through a pipe toidentify such things as lining integrity, density of liquid present, presenceof fluid or gas slugging, solids build-up and other process anomalies.
Effect of Hemodialysis, Coronary Artery Disease and Diabetes on Cardiac Troponin T: A Prospective Survey Over One Year
Authors: Mongeon François-Pierre , Dorais Marc , Lorier Jacques Le , Froment Daniel , Letendre Élaine , Rinfret Stéphane 
Published: June 2009

Background:Limited data is available about the effects of hemodialysis sessions, coronary artery disease (CAD), and diabetes on serum cardiac troponin T (cTnT) levels in patients with end-stage renal disease (ESRD).Objectives:To test whether hemodialysis could be associated with an increase in cTnT concentration. To evaluate if coronary artery disease (CAD) or diabetes are associated with higher cTnT levels in ESRD.Methods:Serum cTnT levels were measured immediately before and after dialysis 3 times over 1 year (0, 6, and 12 months).Results:A total of 100 ESRD patients without acute coronary syndrome (mean age of 58.5 years, 34% with diabetes, and 37% with CAD) gave 267 pre-dialysis and 260 post-dialysis blood samples. The mean (standard deviation) pre-dialysis cTnT levels were 0.06 (0.12), 0.05 (0.06), and 0.07 (0.07) mcg/L at 0, 6, and 12 months, respectively. The post-dialysis cTnT levels were similar on average. Among 259 samples with cTnT measured both before and after dialysis, 79 (30.5%) showed a decrease in serum cTnT, 97 (37.5%) showed an increase and 83 (32%) showed no change following dialysis. Mean cTnT was higher in CAD than in non-CAD patients. We observed no significant difference in mean cTnT levels between diabetic and non-diabetic patients.Conclusions:cTnT levels were not affected by individual hemodialysis sessions, and remained stable around 0.06 mcg/L over a 1-year period in ESRD patients. Random cTnT levels were higher in stable CAD patients undergoing hemodialysis.
Two-dimensional diffusion model for the biopolymers dynamics at nanometer scale
Authors: Paun Viorel 
Published: June 2009

Abstract
In this paper the driven transport of linear polymers through a nanopore is presented. Biopolymer physical behavior in an external electric field is modeled and its motion is simulated using the Langevin impulse integrator method. Within fairly large limits, the polymer translocation time is inversely proportional with the electric field intensity and directly proportional with the polymer chain length.
Wound healing after craniotomy: a randomized trial comparing scalp clips to artery forceps for scalp hemostasis
Authors: Langford Peter , Wolfe Rory , Danks R. Andrew 
Published: June 2009

Object
In this prospective randomized clinical trial, investigators looked at wound healing after craniotomy. The hypothesis was that the self-closing plastic scalp clips used for hemostasis on the skin edge might lead to localized microscopic tissue damage and subsequent delayed wound healing.

Methods
The trial consisted of 2 arms in which different methods were used to secure scalp hemostasis: 1) the routinely used plastic clips (Scalpfix, Aesculap); and 2) the older method of artery forceps placed on the galea. Participants were restricted to those > 16 years of age undergoing craniotomies expected to last > 2 hours. Repeat operations were not included. One hundred fifty patients were enrolled. They were visited at 3 and 6 weeks postoperatively by an observer blinded to the method used, and the wounds were assessed for macroscopic epithelial closure, signs of infection, and hair regrowth by using a predefined assessment scale.

Results
The results showed no significant difference in wound healing between the 2 groups at either 3 weeks (OR 0.55, 95% CI 0.27–1.11; p = 0.09) or 6 weeks (OR 0.79, 95% CI 0.39–1.58; p = 0.50). The length of operation was found to be a significant factor affecting wound healing at 6 weeks (OR/hour 0.68, 95% CI 0.51–0.92; p = 0.01).

Conclusions
The use of Aesculap Scalpfix self-retaining plastic scalp clips on the skin edge during craniotomy surgery does not appear to affect wound healing significantly to the postoperative 6-week mark.
Gamma Knife surgery for lymphocytic hypophysitis
Authors: Ray Dibyendu Kumar , Yen Chun Po , Vance Mary Lee , Laws Edward R. , Lopes Beatriz , Sheehan Jason P. 
Published: June 2009

Lymphocytic hypophysitis is a relatively uncommon autoimmune inflammatory disorder affecting the pituitary gland. It most frequently occurs in women of child-bearing age. The authors report on their experience with a patient who presented with diplopia and marked enlargement of the pituitary gland. She underwent transsphenoidal surgery, and histopathological analysis confirmed the diagnosis of lymphocytic hypophysitis. The disease proved refractory to resection, and any attempt at withdrawal of corticosteroid therapy resulted in a return of the patient's symptoms and enlargement of the sellar contents.
The patient underwent Gamma Knife surgery (GKS) to the sella and both cavernous sinuses. After GKS, the patient was able to discontinue steroid therapy without return of her symptoms. Follow-up MR images demonstrated no evidence of recurrence of lymphocytic hypophysitis.
For persistent lymphocytic hypophysitis, GKS is a reasonable treatment option.
Seismic observations of glaciogenic ocean waves (micro-tsunamis) on icebergs and ice shelves
Authors: MacAyeal Douglas R. , Okal Emile A. , Aster Richard C. , Bassis Jeremy N. 
Published: June 2009

AbstractSeismometers deployed over a 3 year period on icebergs in the Ross Sea and on the Ross Ice Shelf, Antarctica, reveal that impulsive sources of ocean surface waves are frequent (e.g. ∼200 events per year in the Ross Sea) in the ice-shelf and iceberg-covered environment of coastal Antarctica. The 368 events recorded by our field deployment suggest that these impulsive events are generated by glaciological mechanisms, such as (1) small-scale calving and edge wasting of icebergs and ice-shelf fronts, (2) edge-on-edge closing and opening associated with iceberg collisions and (3) possibly the impulsive opening of void space associated with ice-shelf rifting and basal crevasse formation. The observations described here provide a background of glaciogenic ocean-wave phenomena relevant to the Ross Sea and suggest that these phenomena may be exploited in the future (using more purposefully designed observation schemes) to understand iceberg calving and ice-shelf disintegration processes.
Linear stability analysis of an ice sheet interacting with the ocean
Authors: Wilchinsky Alexander V. 
Published: June 2009

AbstractA linear stability analysis of a two-dimensional flow of an isothermal ice sheet interacting with the ocean is considered. The set of boundary conditions determining motion of the grounding line is adopted to describe hydrostatic equilibrium of ice in water and a cubic dependence of the mass flow rate on ice thickness. The numerical analysis shows that the zero-growth (zero-eigenvalue) mode found for linear bed slopes and constant accumulation rates indeed determines neutral equilibrium and separates stable and unstable solutions. It is also argued that, provided some conditions of regularity of the solutions are satisfied, finding only one stable and one unstable solution would be enough to ascertain that the condition determining a zero eigenvalue also determines neutral equilibrium. This supports the intuitive understanding of ice-sheet stability: ice sheets are stable on bed slopes that ensure that the mass flow rate at the grounding line increases faster than the cumulative ice accumulation rate at the surface when the grounding line is perturbed; and ice sheets are unstable otherwise.
A comparative modeling study of the Brunt Ice Shelf/ Stancomb-Wills Ice Tongue system, East Antarctica
Authors: Humbert Angelika , Kleiner Thomas , Mohrholz Chris-Oliver , Oelke Christoph , Greve Ralf , Lange Manfred A. 
Published: June 2009

AbstractTwo diagnostic, dynamic/thermodynamic ice-shelf models are applied to the Brunt Ice Shelf/Stancomb-Wills Ice Tongue system, located off Caird Coast, Coats Land, Antarctica. The Brunt Ice Shelf/Stancomb-Wills Ice Tongue system is characterized as a thin, unbounded ice shelf with an atypical and highly heterogeneous structure. In contrast to other ice shelves, a composite mass of icebergs that calved at the grounding line and were then locked within fast (sea) ice exists between the fast-moving Stancomb-Wills Ice Stream and the slow-moving Brunt Ice Shelf. We simulate the present flow regime of the ice shelf that results from the ice-thickness distribution and the inflow at the grounding line with two different models, and compare the model results with feature tracking and InSAR flow velocities. We then incorporate two observed features, a rift and a shear margin, into the models with two different approaches, and demonstrate the effects of variations in numerical values for the shear strength and viscosity in these zones on the simulated velocity field. A major result is that both kinds of implementation of the rifts lead to similar effects on the entire velocity field, while there are discrepancies in the vicinity of the rifts.
Digital Cities
Authors: Leach Neil 
Published: June 2009

AbstractCode, it would seem, is everywhere. We are beginning to understand that much of our natural environment is based on rule‐based behaviours, from the emergent swarm intelligence of flocks of birds and schools of fish, to the complex patterns of snowflakes, ferns, seashells and zebra skins. And nothing escapes. Not even the human body. The human genome is being mapped out and sequenced by scientists to provide a genetic blueprint of human life itself. In this context, it is hardly surprising that architects are now beginning to explore similar principles in the design studio. Copyright © 2009 John Wiley & Sons, Ltd.
Parametricism: A New Global Style for Architecture and Urban Design
Authors: Schumacher Patrik 
Published: June 2009

AbstractThough parametricism has its roots in the digital animation techniques of the mid‐1990s, it has only fully emerged in recent years with the development of advanced parametric design systems. Patrik Schumacher explains why parametricism has become the dominant, single style for avant‐garde practice today and why it is particularly suited to large‐scale urbanism as exemplified by a series of competition‐winning masterplans by Zaha Hadid Architects. Copyright © 2009 John Wiley & Sons, Ltd.
Chlorofilia, the Los Angeles Jungle
Authors: Leach Neil 
Published: June 2009

AbstractWhen, in 2007, the History Channel invited architects to explore the future of the US metropolis, Hernan Diaz Alonso chose the medium of film to explore the dark side of the city of angels. Neil Leach asked Alonso how he went about challenging the conventional masterplan and provoking with his dystopian view. Copyright © 2009 John Wiley & Sons, Ltd.
I've Heard About … (A Flat, Fat, Growing Urban Experiment): Extract of Neighbourhood Protocols
Authors: Roche François 
Published: June 2009

AbstractUrban models are conventionally planned and intended to control urban systems. François Roche's vision is to the contrary: it is for an unpredictable organic urbanism. A biostructure develops its own adaptive behaviour, based on growth scripts and open algorithms. It is entirely reflexive, responding to human occupation and expression rather than being managed or operated at human will. Copyright © 2009 John Wiley & Sons, Ltd.
A Digital Breeder for Designing Cities
Authors: Batty Michael 
Published: June 2009

AbstractThe idea that inspired designs mirror processes of biological evolution is fast gaining ground as we learn more about how complex systems such as cities function. Michael Batty illustrates how cities can now be grown in ‘digital laboratories’ and, by imposing realistic constraints on their form, begin to breed ‘good designs’ that emerge from continual feedbacks that reinforce the best and iron out the worst. Copyright © 2009 John Wiley & Sons, Ltd.