bluuebunny/crossref_metadata_2025_split huggingface dataset:
Magnolia Deepwater Experience—Frac Packing Long, Perforated Intervals in Unconsolidated Silt Reservoirs
Authors: Eaton Luke F. , Reinhardt W. Randall , Bennett J. Scott , Blake Kenyon , Morales Hugo 
Published: March 2009

Summary
ConocoPhillips is developing the Magnolia field with a tension-leg platform (TLP) in 4,674 ft of water at Garden Banks Block 783 in the Gulf of Mexico. The wells target multiple zones, resulting in complex directional wells with 50–60 maximum hole angles. The wells are completed using dry trees from the TLP and are produced primarily from massive, fine-grained, Pleistocene reservoirs.
These reservoirs require sand control to prevent sand production at the expected drawdowns planned during the life of the wells. To help ensure high-rate, long-life completions, the producing zones are frac packed. The average perforated interval during the initial completion program was 310 ft, with a maximum perforated interval of 571 ft.
The typical production-casing string for the wells consists of 10¾-in. casing with an 8116-in. production liner. Drift diameter through the tapered production casing is 9½ and 6½ in., respectively. The 6½-in. drift diameter allows using common-sized screens and packers. The wells are generally completed with a 4½ × 3½ -in. tapered-tubing string.
Premium screens with shunt tubes are used on the wells because of the long deviated intervals. The "frac-pack" stimulation treatments are pumped at rates of 27 to 40 bbl/min with a viscoelastic-surfactant (VES) carrier fluid. Washpipe-conveyed downhole-pressure and -temperature gauges and radioactive tracers are used to help analyze the treatment results.
This paper will discuss screen-selection philosophy in silt/ very-fine-sand reservoirs, carrier-fluid selection, perforation strategy, and ability to frac across shale intervals. The paper also will cover the effectiveness of achieving a frac pack with premium screens with shunt tubes, on the basis of downhole-pressure and – temperature and radioactive-tracer information, and will discuss revised operational practices that resulted in zero- to negative-skin completions across long, perforated intervals, which continue to produce sand-free after extreme reservoir depletion.
Hydraulic Predictions for Polymer-Thickened Foam Flow in Horizontal and Directional Wells
Authors: Chen Z. , Duan M. , Miska S. Z. , Yu M. , Ahmed R. M. , Hallman J. 
Published: March 2009

Summary
Foam has proved to be effective and economical in underbalanced operations (UBO) and is gaining wider applications in many areas. It provides the desired flexibility in controlling pressure profile and equivalent circulating density (ECD). However, the knowledge of rheology and hydraulics of polymer-thickened foams is still limited. This paper summarizes the significant effects of polymer on foam rheology and presents a hydraulic model that simulates aqueous and polymer-based foam flow in directional and horizontal wellbores.
Experimental studies on the rheology of polymer-enhanced foam were conducted using a specially designed flow-through rotational viscometer and pipe viscometers with different concentrations of hydroxyethylcellulose (HEC) polymer. Correlations have been developed for rheological parameters of aqueous- and polymer-based drilling foams.
On the basis of the experimental results of foam rheology and a steady-state momentum balance equation, a foam-flow hydraulics model was developed to predict pressure profile, ECD, foam velocity, and foam quality along a vertical/inclined/horizontal wellbore. For practical applications, a simulator has been developed and validated by experimental flow-loop data obtained from the Advanced Cuttings Transport Facility of Tulsa University Drilling Research Project. The effects of polymer concentration, backpressure, and wellbore trajectory on foam hydraulics were studied extensively using the simulator. Results show significant impact of polymer on foam hydraulics. When 0.5% volume to volume (v/v) HEC polymer is added to aqueous foam, bottomhole pressure (BHP) and foam density are significantly increased, while foam quality and velocity are greatly decreased. The polymer effects are more pronounced in vertical wells than in horizontal wells.
Simulation results also indicate that it is possible to use foam to create a pressure profile within the narrow window between continuously changing pore-pressure and facture pressure gradients, which is not possible with conventional fluids. Those responsible for hydraulic optimization and well control in managed-pressure drilling/UBO where foam is used will find this paper useful for practical design applications.
Optimization of Deep-Drilling Performance—Benchmark Testing Drives ROP Improvements for Bits and Drilling Fluids
Authors: Judzis Arnis , Bland Ronald G. , Curry David A. , Black Alan D. , Robertson Homer A. , Meiners Matthew J. , Grant Timothy C. 
Published: March 2009

Summary
A critical cost in future deep-oil and -gas recovery is the cost to drill a well. This cost is dominated by the rate of penetration (ROP) that becomes increasingly important with increasing depth. Improving the technology of drilling and increasing the ROP was the object of full-scale laboratory testing conducted under a joint industry and Department of Energy (DOE) program titled "Improving Deep Drilling Performance" (Black and Judzis 2003). Simulations of deep-well drilling in the Arbuckle play and the Tuscaloosa trend were accomplished during 16 full-scale, high-pressure tests using four different 6-in. drill bits, three types of rock, and five different drilling fluids.
This paper describes what is believed to be the first set of full-scale laboratory drilling tests yet performed at bottomhole pressures in excess of 10,000 psi. Accomplishments of the testing and analysis include the following: Laboratory data was compared with field data to confirm that the simulated laboratory conditions provided similar results to what would be expected in the field.ROP reductions were significant when "mudding up" at high bottomhole pressures.Polycrystalline-diamond-compact (PDC) bits provided substantially higher ROP performance than impregnated or roller-cone bits in the environment of this study.The relationship between ROP and confined-rock strength is not a simple function of bottomhole pressure alone.The mechanical specific energy (MSE) when drilling at high bottomhole pressure is often substantially higher than the rock's compressive strength, even when the bit is drilling efficiently.Fluid invasion of intact rock and of rock broken up by the bit's cutting structure seems to play a major role in controlling ROP at these high bottomhole pressures.Drilling-fluid compositions and properties that promote invasion without provoking formation damage, and bit-design features that facilitate the removal of rock debris from the hole bottom, hold promise for improving drilling efficiency in hard rock drilled at high bottomhole pressures.
Special Issues in the Stress Analysis of Casing Strings in Steam-Injection Wells: Mathematical Development and Design
Authors: Garside R. , Pattillo P. D. , Pattillo II P. D. , Sathuvalli U. B 
Published: March 2009

The design and development of steam-injection fields is a mature subject. Because the tubulars in these wells invariably experience inelastic loading, issues such as the effects of temperature on the static and cyclic (fatigue) material properties become important. The original papers that address steam-injection casing-design issues date back to the 1960s. These studies include temperature prediction (Leutwyler and Bigelow 1965), casing-stress analysis (Willhite and Dietrich 1967), and development of design guidelines (Holliday 1969). Though these works acknowledge the role of temperature on the static and cyclic material properties, data on the cyclic thermal properties of oil-country tubular-goods steels rarely appear in oilfield literature (Placido et al. 1997; Maruyama et al. 1990).
This paper presents a mathematical model of casing strings subjected to thermal loads in steam-injection wells. The model includes the effects of temperature on material properties and the effects of wellbore curvature and prestress during the heating cycle. Several counterintuitive aspects of the casing-stress state during cooling/unloading are examined. Further, the general equations are shown, with appropriate simplifications, to reproduce the earlier work (Willhite and Dietrich 1967; Holliday 1969). Example calculations are used throughout to illustrate key insights.
Sand Exclusion and Management in the Okwori Subsea Oil Field, Nigeria
Authors: Guinot Frédéric , Douglass Stuart , Duncan Jim , Orrell Martin , Stenger Bruno 
Published: March 2009

Summary
Several downhole-sand-control failures in Okwori subsea oil producers triggered a significant overhaul of the downhole-sand-control method and a review of topside sand management. Because the eventuality of further downhole-sand-control failures in existing producers could not be ignored, a surface-sand-handling and -management facility was designed. For the future development producers, the downhole-sand-control method was re-engineered to increase its reliability. The initial multizone, fully selective sand-control-completion system, with expanded sand screens inside the casing, was abandoned. A revised openhole sand control was designed with similar completion selectivity. The new completion system implied a change in drilling practices, in reservoir drill-in fluid, and in filter-cake-cleanup techniques that required simultaneous engineering. These revisions were validated and implemented only a few months after encountering the first major sand-control failure. The Okwori floating production, storage, and offloading (FPSO) vessel was not expected to deal with sand production. Temporary sand traps were installed to minimize production downtime and to determine flow regimes that minimized sand production. Severe-service adjustable chokes were introduced to avoid valve erosion and stabilize production rates. Finally, a long-term topside-sand-management solution was designed and recommended for implementation.
Evaluation of the Potential for Gas and CO2 Leakage Along Wellbores
Authors: Watson Theresa L. , Bachu Stefan 
Published: March 2009

Summary
Implementation of carbon dioxide (CO2) storage in geological media requires a proper assessment of the risk of CO2 leakage from storage sites. Leakage pathways may exist through and along wellbores, which may penetrate or be near to the storage site. One method of assessing the potential for CO2 leakage through wells is by mining databases that usually reside with regulatory agencies. These agencies collect data concerning wellbore construction, oil and gas production, and other regulated issues for existing wells. The Alberta Energy Resources Conservation Board (ERCB), the regulatory agency in Alberta, Canada, collects and stores information about more than 315,000 oil, gas, and injection wells in the province of Alberta. The ERCB also records well leakage at the surface as surface-casing-vent flow (SCVF) through wellbore annuli and gas migration (GM) outside casing, as reported by the industry.
The evaluation of a leakage pathway through wellbore casing or annuli and what causes these wellbore leaks are the first step in determining what factors may contribute to wellbore leakage from CO2-storage sites. By using available data, major factors that contribute to wellbore leakage were identified.
Data analysis shows that there is a correlation between these SCVF/GM and economic activity, technology changes, geographic location, and regulatory changes regarding well completion and abandonment. Further analysis indicates a relationship between low-annular-cement top, external corrosion, casing failure, and wellbore leakage (SCVF/GM). Other factors that could affect the presence of wellbore leakage, such as wellbore deviation, surface-casing depth, and wellbore density, were also investigated.
This paper presents the findings of the data analysis and a method to evaluate the potential for leakage along wells in an area where CO2 storage is intended. This information is useful not only for future operations of CO2 storage in geological media, but also for current operations relating to the exploration and production of hydrocarbons.
Finite-Element Studies of Near-Wellbore Region During Cementing Operations: Part I
Authors: Gray K. E. , Podnos E. , Becker E. 
Published: March 2009

Summary
A wellbore cement sheath is expected to provide zonal isolation and borehole integrity during well construction and well life. Mechanical interactions of the cement sheath to existing and operationally induced stresses, along with other elements in proximity to the wellbore, have increasingly large technical, economic, and environmental ramifications.
Staged-finite-element procedures during well construction consider sequentially the stress states and displacements at and near the wellbore. The model replicates complicated stress states arising from simultaneous action of far-field stresses, overburden pressure, cement hardening and shrinkage, debonding at the interfaces, and plastic flow of cement sheath and rock formation. At present, temperature, flow, and poroelasticity effects are not included. The technique tracks the time-dependent behavior of cement slurry, curing (with or without shrinkage), and hardened cement during the critical period after slurry placement.
Material models for casing, cement, and rock formation and failure criteria for cement, formation, and interface bonds were calibrated using published information and experimental data. Calculations were conducted for various loading and unloading scenarios, geometric configurations, properties of rock formations, and cement-slurry formulations. Results are discussed in terms of field implication;, for example: (1) Interface microchan-nels may or may not develop, depending upon shrinkage magnitudes; and (2) simplifying modeling assumptions that are often used, such as 2D stresses and/or deformations, may obscure critical casing, cement, and formation behavior in the wellbore region and in the producing horizon.
This paper, part of a series quantifying the interacting physical components and processes at and near the wellbore region, initiates useful comparisons of analytical results and field realities. The series illustrates and compares results and practical implications from simple to increasingly complex, but more realistic, assumptions, such as isotropic/directional-stress states and isotropic/anisotropic casing, cement, and formation-material parameters.
Policies to Deal with the Implosion in the Mortgage Market
Authors: Shiller Robert J. 
Published: March 2009

Abstract
This paper relates the 2006-2008 meltdown in mortgage markets to falling asset prices, excessive psychological reaction to the burst bubble, and new mortgage vehicles incapable of accommodating sudden changes in asset values. A combination of market-based and regulatory innovations are proposed. The paper suggests placing greater reliance on innovative futures markets in real estate, inducing the flow of capital to vehicles having self-regulatory features and cultivating resiliency in the market. The bankruptcy law also might come to include circuit breaker" delays in finalizing settlements during turbulent market settings. Some of the fundamental premises underlying mortgage finance should also be reconsidered. Stakes in individual residences could be combined with stakes in regional property portfolios. Finally, the paper promotes a system of continuous workout mortgages" regularly readjusting loan balances to reflect economic conditions. These contracts could provide needed flexibility; they also offer systematic advantages over the various sector-based bailout strategies inherent in current loan-modification proposals.
The Mortgage Market Meltdown and House Prices
Authors: Hubbard R. Glenn , Mayer Christopher J 
Published: March 2009

Abstract
This paper argues that the U.S. mortgage debacle must be analyzed in the broader setting of global real estate markets. Recent U.S. home price growth closely tracked increases in other developed economies. The analysis distinguishes among market regions in terms of supply elasticity and localized transactions-costs. A series of user-cost models are presented which imply that interest rate fluctuations must figure prominently in any explanation of movements in price/rent ratios. National factors such as the expansion of subprime credit must also be accounted for. The paper concludes with policy prescriptions addressing rapid price declines and elevated interest-rate spreads. We argue that the federal government should play a leading role in helping to reduce interest rates on new mortgages and cushion against underwriting losses on the existing balance sheets of lenders.
Three Initiatives Enhancing the Mortgage Market and Promoting Financial Stability
Authors: Hancock Diana , Passmore Wayne 
Published: March 2009

Abstract
In recent years, the government has greatly extended its reach into the mortgage markets with the goals of (1) mitigating the deadweight losses associated with mortgage foreclosures, (2) promoting affordable homeownership, and (3) providing low cost mortgage financing. In this paper, we identify three innovations-one in each of these areas-that could be made to the American mortgage market that would help obtain the government's objectives while enhancing financial market stability-particularly if all are done together. These three innovations are: (1) buy your own mortgage" options, (2) variable maturity mortgages, and (3) creation of a government mortgage bond insurer, with an emphasis on insuring covered bonds as well as GSE debt. The first innovation would allow homebuyers to repurchase their mortgage at the market value" of their homes when they move, thereby helping society avoid some of the deadweight losses associated with unnecessary foreclosures. The second innovation would provide a mortgage that could promote affordable housing without unduly raising the default risks of low- and moderate-income families. The third innovation would help create a variety of financing options for mortgages in the United States. Moreover, it could be integrated into the current system of mortgage financing, which would include government-sponsored enterprises (GSEs), in a manner that would help the government manage the systemic risks associated with the quasi-government backing of mortgage credit and mortgage insurance. In particular, we propose that the government explicitly insure pre-designated financial instruments used to fund mortgage credit (such as covered bonds and GSE debt) by creating a government-backed insurance fund similar to that currently used for deposits.
Homes and Cars: Why are the Cycles in Homes and Consumer Durables so Similar?
Authors: Leamer Edward E 
Published: March 2009

Abstract
This paper reports three sets of facts: 1) Declines in housing are very good predictors of oncoming recessions in the U.S.; 2) Housing and consumer durables are the most important components of GDP that are soft prior to the official beginnings of recessions, and these two contribute substantially to weakness during recessions; and 3) The cycles in homes and consumer durables are very close, raising the prospect that a monetary rule that targeted housing would alleviate the cycle in consumer durables as well; this is confirmed in an econometric exercise with rates set to stabilize housing starts.These facts are used to argue in favor of monetary policy that prevents excessive building of homes and cars with preemptive rate increases in the middle of expansions when housing starts are above normal and growing higher. This contrasts with the traditional approach which is to raise rates late in expansions when inflation is apparent, but when the markets for homes and durables are very fragile because of excessive building earlier.
Microstructure of a ternary Al–Pd–Rh alloy
Authors: Svoboda Milan , Buršík Jiří , Janovec Jozef , Kriška Martin , Kusý Martin , Švec Peter 
Published: March 2009

Abstract
The characterization of phases in a ternary Al – Pd – Rh complex metallic alloy annealed at 1100 °C for 49 h before (original state) and after differential thermal analysis was performed. In the investigation, light microscopy, scanning and transmission electron microscopy, energy-dispersive X-ray spectroscopy, wavelength-dispersive X-ray spectroscopy, and differential thermal analysis were used. The dominant constituent in the original state was characterized as ∊6-phase. The minor constituent was attributed to the additionally solidified liquid co-existing with the ∊6-phase at 1100 °C. After differential thermal analysis, the microstructure of the alloy was composed of the matrix ∊6-phase and areas of the creek-type morphology.
High-temperature mechanical properties of Fe-40 at.% Al based intermetallic alloys with C or Ti addition
Authors: Karlík Miroslav , Haušild Petr , Šíma Vladimír , Málek Přemysl , Vlasák Tomáš 
Published: March 2009

Abstract
Tensile and creep properties of vacuum-induction-melted and cast Fe-40Al-1C and Fe-40Al-1Ti (at.%) were studied. The ingots were hot-rolled at 1200 °C to plates of 12.5 mm thickness using a stainless steel sheath and cooled in air. The alloys showed microstructures with coarse elongated grains having diameters up to 500 and 300 m in the direction of rolling, respectively. Tensile tests were carried out at temperatures 20, 400, 600, 700, and 800 °C. The creep tests were performed under constant load of 100 MPa and 150 MPa at temperatures 550, 600, 650, and 670 °C. Fracture surfaces of tensile specimens tested up to 700 °C exhibited mainly intergranular decohesion. With increasing temperature, the proportion of ductile dimpled fracture increased, and at 800 °C the fracture surfaces of both alloys were practically completely covered by ductile dimples. In comparison to tensile test specimens, fracture surfaces of creep specimens showed an increased fraction of intergranular ductile fracture.
Phase composition and morphology development in WE-type alloys modified by high Zn content
Authors: Smola Bohumil , Stulíková Ivana , Žaludová Nad'a , Hnilica František , Janík Vít , Očenášek Vladivoj 
Published: March 2009

Abstract
Quasicrystalline icosahedral equilibrium phase was found in Mg – Y – Nd (WE43) alloys with the addition of 12 wt.% and 25 wt.% Zn constituting grain boundary eutectic phases. In response to the isochronal annealing, morphologically similar precipitates of phases with the same structure as those developing during heat treatment of binary Mg-8 wt.% Zn alloy at temperatures higher than 150 °C were observed, namely β (b-centered monoclinic crystal structure a = 2.596 nm, b = 1.428 nm, c = 0.524 nm, = 102.5°) and β (hexagonal MgZn2). The evolution of the resistivity and microhardness during isochronal annealing corresponds to the phase transformations and the morphology changes of the phases observed. Dislocations with the c Burgers vector component generated due to the presence of icosahedral phase are responsible for the improved formability as compared to the WE43 alloy.
Influence of titanium volume fraction on the mechanical properties of Mg–Ti composites
Authors: Pérez Pablo , Garcés Gerardo , Adeva Paloma 
Published: March 2009

Abstract
The influence of titanium volume fraction on the mechanical properties of Mg – Ti composites prepared through a powder metallurgy route has been evaluated. Titanium was added as particles smaller than 25 m and volume fractions ranging from 5 to 15 %. The increase in the volume fraction of titanium particles results in a slight decrease in the maximum strength. In contrast to this, the ductility of all composites was significantly enhanced by titanium additions. The mechanical properties can be explained on the basis of texture changes induced by the presence of titanium particles. The decrease in the basal texture along the extrusion direction as the amount of titanium is progressively increased accounts for the decrease in the maximum strength.