bluuebunny/crossref_metadata_2025 huggingface dataset:
Selection for Preservation in the Digital Age: An Overview
Authors: Gertz Janet
Published: December 2007

In this paper, I consider three issues: whether conversion to digital form is a preservation action, the contrasts between selection for digital conversion and selection for traditional preservation, and the potential effects on the field of preservation. All of these issues are under active debate by, among others, Atkinson (1998), Conway (1996b), Hazen et al. (1998), and Smith (1999). While consensus is growing, many points remain unsettled.
DatagraphiX ImageMouse Digital Retrieval System
Authors: Battleson Brenda L.
Published: December 2007

A relatively new product for microform image capture is the DatagraphiX ImageMouse Digital Retrieval System, developed by Anacomp, Inc. ImageMouse (IM) is a compact device that takes up little more desk space than a standard 3-ring binder and enables a user to digitize, display and print a microfiche image using an existing standard computer workstation.
The Metamorfoze Preservation Programme
Authors: Langendoen Andrea
Published: December 2007

Sometime in the 1490s, a Benedictine monk by the name of Johannes Trithemius was deeply concerned about how long the newfangled invention of printing, on paper, would endure:

For handwriting placed on parchment will be able to endure a thousand years. But how long, forsooth, will printing last, which is dependent on paper? For if a paper volume lasts for two hundred years that is a long time.
VISUAL REVIEWS
Authors: Hansen Karen Tranberg
Published: December 2007

Mama Benz and the Taste of Money. Karin Junger, producer. 52 min. Color. New York: Filmakers Library, 2002.
VISUAL REVIEWS
Authors: Safa Helen
Published: December 2007

Store Wars: When Wal‐Mart Comes to Town. Micha X. Peled, producer and director. 59 minutes. Color. Oley, PA: Bullfrog Films, 2001. [for rental/purchase information see web site: http://www.bullfrogfilms.com]
Appropriating Identity or Cultivating Capital? Global English in Offshoring Service Industries
Authors: Sonntag Selma K.
Published: December 2007

In the popular media, much has been made of the adoption of American identities by Indian nationals working in call centers in urban India. In the transactions between call center workers in India and their American customers, language is often the only conveyor of cultural identity. The implications of this linguistic globalization are drawn out by examining the historical trajectory of the politics of global English in India. I argue that the indigenization of English that has occurred in India represents a shift in the political and cultural contestation over language from the global to the local, so that today the politics of language in India primarily involve contestation between elites and subalterns within India rather than between Indians and a global power. I conclude that the appropriation of American identities by Indian call center workers is mainly for the purpose of cultivating linguistic capital within the Indian context, and does not entail a loss of authenticity or reveal cultural insecurity. More likely, the American customers and media commentators who worry about being duped by Indians faking American accents are the ones who are culturally insecure.
The New Economy and Transforming Employment Relations: A Review Essay
Authors: Karjanen David
Published: December 2007

The State of Working America 2004/2005. Lawrence Mishel, Jared Bernstein, and Sylvia Allegretto. Ithaca, NY: Cornell University Press, 2004.

The Betrayal of Work: How Low‐Wage Jobs Fail 35 Million Americans. Beth Shulman. New York: The New Press, 2003.

Low‐Wage America: How Employers Are Reshaping Opportunity in the Workplace. Eileen Appelbaum, Richard J. Murnane, and Annette Bernhardt, editors. New York: Russell Sage Foundation, 2003.

The Working Poor: Invisible in America. David K. Shipler. New York: Knopf, 2004.
BOOK REVIEW: The New Economy and Transforming Employment Relations: A Review Essay
Authors: Porter Karen A.
Published: December 2007

The Package Deal: Marriage, Work and Fatherhood in Men's Lives. Nicholas W. Townsend. Philadelphia, PA: Temple University Press, 2002.
BOOK REVIEW: The New Economy and Transforming Employment Relations: A Review Essay
Authors: Antonio Patricia San
Published: December 2007

Sweet and Sour: Life Worlds of Taipei Women Entrepreneurs. Scott Simon. Lanham, MD: Rowman and Littlefield, 2003.
BOOK REVIEW: The New Economy and Transforming Employment Relations: A Review Essay
Authors: Gresh Rebecca
Published: December 2007

Framed! Labor and the Corporate Media. Christopher R. Martin. Ithaca, NY: ILR and Cornell University Press, 2004.
Covert Mentoring on the Internet: Methods for Confirming Status in Imagined Technical Communities
Authors: Lange Patricia G.
Published: December 2007

Many technologists rely on informal mentoring conducted in social circles that lie outside of their immediate workplace. One crucial mentoring method involves answering questions, which may help novices solve problems, master technical skills, and learn proper social behavior. Yet, asking and answering questions can mark the questioner and/or respondent as lacking knowledge or competence. Questioners and respondents may address these vulnerabilities by using strategies that deflect away from their perceived inadequacy and focus instead on the proper content and form of acceptable questions. Rather than focusing on the technical answer to a question, respondents criticize the questioner and teach questioners how to ask questions properly. These tactics strive to help questioners regain techno‐social capital that is lost when they cannot demonstrate adequate technical knowledge. Based on a two‐year ethnographic study of two online communities, this paper examines the strategies questioners and respondents use to ask and answer questions in ways coded as socially appropriate in local contexts. Rather than circulating new technical knowledge, these exchanges result in a type of covert and collusional mentoring which trains participants to ask and answer questions in socially acceptable ways. Ironically, these question‐and‐answer practices may encourage both questioner and respondent to use and reinforce normative cultural practices that no one may actually value.
BOOK REVIEW
Authors: Krishnamurthy Mathangi
Published: December 2007

The Intimate Economies of Bangkok: Tomboys, Tycoons, and Avon Ladies in the Global City. Ara Wilson. Berkeley: University of California Press, 2004.
Situated Learning for an Innovation Economy: E‐Commerce and Technology as a Mediator for Rural High School Students' Sense of Mastery and Self‐Efficacy
Authors: Michaelson Karen L.
Published: December 2007

Practitioners focusing on technology and workforce development reference the need to prepare individuals for an Innovation Economy. Yet innovation is socially constructed, as much social as it is technical. Observation of 160 high school students from very rural schools participating in a school‐based e‐commerce curriculum indicates that there are knowledge sets acquired through carefully constructed experiential learning that foster a context for innovation. This counters factors in the traditional education/workforce development system that impede the development of innovators, including a narrows skills‐based focus and the demonization of failure. Situating innovation in historical context and in the lived experience of individual networks helps to understand the innovation process and provides a framework for the development of effective educational experiences.
Learning and Knowledge in an Office Workplace: Perceptions of the Recently Unemployed
Authors: Letkemann Paul G.
Published: December 2007

This paper uses interview data from employees and former employees of a Regional Land Use Planning Commission Office in Alberta, Canada. This workplace is unified by a sense of common social and environmental purpose revolving around the Regional Planning Act of Alberta. Occupationally specific contextual parameters allow collective recognition of roles symbolizing knowledge acquisition, contributing to self‐validation in the workplace. By emphasizing perceptions of recently unemployed people, this paper incorporates what Marcus called 'processes of reconceptualization' in understandings of the importance of workplace achievement and position. Dislocation from workplace position is also removal from ongoing processes of learning, teaching, applied knowledge and social contribution. In rethinking their loss, the recently unemployed express often‐overlooked interpretations of knowledge based workplace dynamics.
BOOK REVIEW: REVIEW ESSAY California Farmiń: Promise and Reality
Authors: Lee Anru
Published: December 2007

Making Sweatshops: The Globalization of the U.S. Apparel Industry. Ellen Israel Rosen. Berkeley: University of California Press, 2002.
BOOK REVIEW: REVIEW ESSAY California Farmiń: Promise and Reality
Authors: Johnson Leslie
Published: December 2007

A Time for Tea: Women, Labor, and Post/Colonial Politics on an Indian Plantation. Piya Chatterjee. Durham: Duke University Press, 2001.
Theorizing Unemployment: Toward an Argentine Anthropology of Work
Authors: Perelman Mariano D.
Published: December 2007

The recent crisis related to neoliberal economic policies in Argentina brought more of a focus in Argentine anthropology to issues related to work and unemployment. The anthropology of work, before the crisis, was a neglected area of the discipline. I am proposing that we pay theoretical attention, in and beyond Argentine anthropology, not only to labor relations and conditions, but also to the subjectivities and collective actions within the growing unemployed and underemployed population in Argentina. Unemployed individuals still conceptualize of themselves as workers; it is how they have constructed their identities. A theoretical focus on the unemployed in the anthropology of work will contribute to our understandings of heterogeneous capitalist relations and subjectivities.
Book Reviews
Authors: Whitaker Robin
Published: December 2007

Sheltering Women: Negotiating Gender and Violence in Northern Italy. Sonja Plesset. Stanford, CA: Stanford University Press. 2006. 250 pages. 978‐0‐8047‐5301‐2.
Interactions between Slimy Sculpin and Trout: Slimy Sculpin Growth and Diet in Relation to Native and Nonnative Trout
Authors: Zimmerman Julie K. H. , Vondracek Bruce
Published: December 2007

To investigate whether introductions of nonnative trout affect growth and diet of nongame fish in small streams, we designed a field experiment to examine interactions between slimy sculpin Cottus cognatus and native brook trout Salvelinus fontinalis or nonnative brown trout Salmo trutta. We hypothesized that brown trout would compete with and reduce growth of slimy sculpin. We expected no change in slimy sculpin growth in treatments with brook trout because the two species co‐occur in their native range and thus may have evolved methods to partition resources and decrease competitive interactions. Enclosures (1 m2) were stocked with (1) juvenile brown trout and slimy sculpin, (2) juvenile brook trout and slimy sculpin, or (3) slimy sculpin alone (control). Fish were stocked at three densities to examine intraspecific versus interspecific competition. Replicates of each treatment were placed in riffles in Valley Creek, Minnesota, and six experimental trials were conducted over three summers (2002‐2004). Brown trout presence was associated with reduced growth of large slimy sculpin in enclosures, whereas brook trout presence produced no change in slimy sculpin growth; these effects did not depend on fish density. Brown trout or brook trout presence was not associated with shifts in the diets of slimy sculpin, indicating that reduced slimy sculpin growth in the presence of brown trout was not due to prey selection or prey availability changes. Our research suggests that effects on growth of slimy sculpin in Valley Creek differ between introduced brown trout and native brook trout; however, the mechanisms underlying changes in slimy sculpin growth are unclear. Although brook trout and brown trout appear to fill similar ecological roles in small, coldwater streams, brown trout may negatively impact growth of nongame fish.
Ontogenetic Diet Shifts of Prickly Sculpin in the Lake Washington Basin, Washington
Authors: Tabor Roger A. , Warner Eric J. , Fresh Kurt L. , Footen Brian A. , Chan Jeffrey R.
Published: December 2007

We studied the ontogenetic diet shifts of prickly sculpinCottus asper(the largest North American freshwater cottid) in the Lake Washington basin from a variety of habitat types, including fluvial and lacustrine. In all habitats, prickly sculpin progressively shifted to larger prey, such as fish and crayfish (Decapoda), as they increased in size. In offshore areas of Lake Washington, amphipods were the dominant prey by weight consumed by prickly sculpin of 75‐124 mm total length (TL). Although generally uncommon numerically in the diet, fish (primarily small cottids) made up a large percentage of the diet by weight for prickly sculpin larger than 125 mm TL. In the lower end of the Cedar River, juvenile sockeye salmonOncorhynchus nerka(23‐30 mm TL) were most commonly observed in the diets of 50‐99‐mm prickly sculpin, while larger prickly sculpin tended to consume larger fish, including adult longfin smeltSpirinchus thaleichthys, lampreysLampetraspp. (ammocoetes and adults), and small cottids. For each habitat type, diet overlap tended to decrease as size‐classes became more dissimilar. Overall, the size of fish eaten was strongly related to prickly sculpin size, but the type of fish eaten influenced the relationship between prey size and predator size. The higher percentage contribution of fish to prickly sculpin diets seen here relative to other studies can be explained by the fact that (1) we collected many large prickly sculpin and sampled a wide variety of habitat types and (2) potential prey fish in the Lake Washington system are abundant and diverse. Our results, in combination with other research on the Lake Washington ecosystem, suggest that because of their size, abundance, wide range in habitat use, and breadth of diet, prickly sculpin are an especially important species in the food web of this system. Prickly sculpin are directly linked to the pelagic food web as both predators and prey, and they play a key role as benthic predators.
Size‐Dependent Territoriality of Mottled Sculpin in a Southern Appalachian Stream
Authors: Petty J. Todd , Grossman Gary D.
Published: December 2007

We quantified the space use behaviors of juvenile and adult mottled sculpinCottus bairdiiover a 3‐year period in Shope Fork, western North Carolina. Our objectives were to (1) quantify home range size, (2) determine whether the fish exhibit territorial behaviors, (3) characterize the relative stability of territories, and (4) relate temporal variation in behaviors to environmental variability and population size structure. Adult behaviors were consistent with those of a strongly territorial organism. Adults exhibited nonrandom movements, restricted home ranges, and extremely low levels of spatial overlap with neighboring residents (<10% overlap). Territories were established in erosional microhabitats that were significantly more stable (as measured by seasonal shifts in dominant substrate composition) than randomly selected microhabitats in the study site. In contrast to adults, juveniles did not exhibit evidence of territoriality and instead occupied overlapping home ranges (16‐36% overlap) in less‐stable, depositional microhabitats along the stream margin. Mottled sculpin home range size, home range overlap, and territory abandonment rate were related to the density of large adults rather than flow variability or microhabitat stability. Adult territoriality and juvenile floating provide behavioral mechanisms capable of producing strong regulation of mottled sculpin populations in this system.
The northern ice cap of Mars: an enigmatic evolution compared to the polar environment on Earth
Authors: Rognon Pierre , Desjardins Robert , Dawidowicz Gilles
Published: December 2007

Would it be possible to interpret the dynamics of the northern polar ice cap of Mars with the same criteria as for terrestrial ice sheets? The aim of this paper is to illustrate the problems posed by such an approach. We present a detailed study of the MOC narrow angle image E01-01773, taken at 83.5°N/241.4°W in the upper part of a 300 km-long depression situated at the edge of the northern polar ice cap. On Mars, every depression resembling a valley is a “chasma”, and as this one has no official name, we suggest to call it “West Olympia Chasma” (WOC). By analyzing the satellite image, we have been able to highlight some unusual features of martian glacial geomorphology and to compare them with topographies and sediments known in terrestrial glacial environments. In particular:

– the scarp cutting the edge of the ice cap above the chasma is formed of thin alternations of ice and aerosols and is bordered by numerous small and dissymetrical ridges that run parallel to it. On Earth, these ridges would be interpreted as a succession of terminal moraines; in fact, they consist of gravitational debris accumulated under the nearly motionless ice cliff;

– at the edge of the ice, where signs of melt water action would be clearly visible in terrestrial environments, there is practically no evidence of such a process on Mars. However, two intriguing channels, several tens of meters wide and about 1 km-long, suggest the occurrence of temporary water flow;

– these channels originate at the base of an ice tongue that appears to have flowed recently over the scarp towards the floor of the chasma, in the same manner as surging glaciers on Earth, whereas Mars ice seems motionless;

– the sandy sediments covered by the ice cap do not seem to be ground moraines, as would be the case on Earth, but eolian sand brought by winds when the ice cap did not exist.

At present, the most effective erosion agents are the winds channelled into the chasma and the alternations of condensation/sublimation. Their combined action explains the dissymetry between both sides of the chasma. The winds are enhanced by local topography and contribute to the movement of dunes towards the outlet of the chasma.
Thermodynamic Modeling of Pseudoternary Phase Behavior
Authors: Rossen William R. , Brown Roger G. , Davis H. Ted , Prager Stephen , Scriven L. E.
Published: December 2007

Phase behavior is the fulcrum at which the chemistry and physics of surfactant and solvent systems govern the engineering and economics of chemical flooding. Salient behavior is represented by pseudoternary diagrams that account for polar, nonpolar, and amphiphilic components. The common 2_,3,2¯, phase-split progression—induced, for example, by salinity change in microemulsion systems—is required by thermodynamic principles. Although such progressions can be simulated semiempirically, modeling them with a suitable free-energy function or an equation of mixture state is more reliable for interpolating and extrapolating limited data on phase splits and coexisting phase compositions for use in mechanism-based computer simulation of laboratory experiments and field applications.

Simple equations of mixture state prove inadequate but lead to the promising new linearly screened Flory-Huggins (LSFH) equation, which accounts for simultaneous association of amphiphile with oil and water and aggregation of surfactant amphiphile into curved sheetlike structures that separate water-rich from oil-rich regions. From this equation for a ternary mixture are calculated representative sets of diagrams with continuous progressions of tielines and binodals, plait points, tie-triangles, and three-phase regions with their critical endpoints. Several overlapping regions of metastable one- and two-phase equilibria are identified. Free-energy surfaces are pictured, and the free-energy factor that jointly controls interfacial tension (IFT) is computed. Ultralow tensions are favored by low-relief free-energy surfaces; so also are long-lived metastable states. The exponentially screened Flory-Huggins (ESFH) equation, superior in some ways to the linearly screened version, also is discussed briefly.

Computational methods are described for fitting the six parameters of the ternary equation to data as well as for predicting phase behavior from given parameters.
Steam Distillation of Crude Oils
Authors: Duerksen J. H. , Hsueh L.
Published: December 2007

The objectives of this investigation were to generate crude oil steam distillation data for the prediction of phase behavior in steamflood simulation and to correlate the steam distillation yields for a variety of crude oils. Thirteen steam distillation tests were run on 10 crude oils ranging in gravity from 9.4 to 37°API (1.004 to 0.840 g/cm3). In each test the crude was steam distilled sequentially at about 220, 300, 400, and 500°F (104, 149, 204, and 260°C). The cumulative steam distillation yields at 400°F (204°C) ranged from about 20 to 55 vol %.

Experimental results showed that crude oil steam distillation yields at steamflood conditions are significant, even for heavy oils. The effects of differences in steam volume throughput and steam temperature were taken into account when comparing yields for different crudes or repeat runs on the same crude. Steam distillation yields show a high correlation with crude oil API gravity and wax content.
An Improved Simulation for Interpreting Temperature Logs in Water Injection Wells
Authors: Fagley John , Fogler H. Scott , Davenport C. Brent , Millhone R. S.
Published: December 2007

An improved simulation for temperature logs (TL's) in water injection wells is described. Improvements based on the reduction of assumptions used by previous investigators are demonstratedby comparison of field data and simulator results showing excellent agreement of TL profiles over the entire well depth. Initial work with the simulator has demonstrated the need for different operational procedures for definite TL surveys in mature wells (those having received significant long-term injection) as compared with young wells. The utility of short-period hot water (SPHW) injection just preceding shut-in as an injection profile amplifying scheme has been investigated in depth through the TL simulator. Finally, sensitivity studies have been run to identify the most important TL parameters and to develop guidelines for improved profiling.
Pressure Transient Analysis in Poorly Consolidated Reservoirs
Authors: Ichara Mark J. , Caudle Ben H.
Published: December 2007

This study uses a numerical solution technique to investigate the effect on well test data of sand accumulation in the wellbore from poorly consolidated reservoirs. The results show that in anisotropic reservoirs, this sand column creates a pressure drop in the wellbore similar to that caused by infinitesimally thin skin around the wellbore. In this case, however, the slope of the semilog straight line for a buildup test is increased, indicating that the conventional analysis method would not yield accurate results.

Log-log type curves and semilog plots of dimensionless pressure vs. dimensionless time are presented in this paper for different cases. These graphs can be used to detect the presence of sand in the wellbore and to analyze the transient pressure data instead of the Horner and Miller-Dyes-Hutchinson (MDH) methods. Graphs for various cases are provided for use in determining the pseudoskin factors caused by the presence of a sand column in the wellbore.
Silicones: Unique Chemicals for Petroleum Processing
Authors: Pape Peter G.
Published: December 2007

Silicones are specialty chemicals that are often critical in certain production operations. Their primary use in petroleum applications is as foam control agents. The physical and chemical properties of silicones are described, and foam and antifoam theory is discussed. State-of-the-art silicone use in selected key petroleum applications is outlined. The unique properties of silicones that should be considered by petroleum engineers in solving problems in other types of applications are emphasized.

Introduction

It is ironic that a material not present on earth naturally can be a critical material in the production of one of the earth's most desirous natural resources-crude oil. But such is the case with silicones and their use as foam control agents in certain petroleum processes.

Silicones are not present in nature. They must be made by a complex process that starts with sand or quartz and ends with highly refined chemicals with unique physical and chemical properties. Ref. 1 provides a comprehensive review of silicone chemistry and technology.

Silicones were not available commercially until 1943. Since that time, silicones have experienced a phenomenal growth in volume, types of products, and number of applications. While important in many industries, silicones or the manner in which they can best be used very often are not fully understood by the application engineer.

This paper describes the nature of silicones and the physical and chemical properties that make them unique. The relationship of these properties to present and potential applications in the petroleum industry is discussed. Specific emphasis is placed on their use as foam control agents in petroleum processes.

Nature of Silicones

To better understand silicones, it is useful to examine in greater detail the most common of the silicone products, polydimethylsiloxanes. Structurally, a polydimethylsiloxane (PDMS) consists of a polymeric inorganic backbone of alternating silicon and oxygen atoms with methyl groups attached to silicon, represented by

The value of n, or the degree of polymerization, can range from 0 to 2,500 and can be controlled to give fluids with viscosities from 0.65 to 10(6) cp (0.65 × 10(-3) to 10(3) Pa.s) at 77 degrees F (25 degrees C). Unlike hydrocarbons, which become waxes or solids beyond chain lengths of C 14, silicones, particularly PDMS, are colorless liquids or flowable gums even at very long chain lengths. Except at very short chain lengths, silicones can be regarded as nonvolatile polymers with very low vapor pressure, even at high temperatures.

PDMS materials are nonpolar and nonionic, are very insoluble in water, and are hydrophobic to the extent that an important use is as a water repellent. They arc soluble in common organic solvents such as diesel fuel, kerosene, and toluene.

JPT

P. 1197^
A Study of the Dual-Water Model Based on Log Data
Authors: Coates George R. , Boutemy Yves , Clavier Christian
Published: December 2007

This paper presents log evidence in support of the dual-water model. Included are basic studies that illustrate the model from the aspect of conductivity measurements, porosity and formation factor relationship, and the contrast to the prediction of Waxman and Smits' cation exchange capacity (CEC) model (W-S model).

Introduction

Since the introduction of the theoretical dual-water model in 1977, there has been considerable conjecture on the scientific aspects of- the CEC models.

This paper intentionally avoids theoretical areas and concentrates instead on what can be observed from log, data with respect to the conductivity and porosity of shales, shaly sands, and sands. In addition, the dualwater hypothesis is expounded as a means of shedding new light on the troublesome problem of applying a formation factor relationship in shaly formations.

The Dual Water Observed

Studies of factors that influence the attenuation of electromagnetic propagation signals from EPT logs revealed that plots of attenuation rate as a function of the total porosity index always displayed similar trends, with the shales showing the greatest uniqueness. Fig. 1, which is a hand composite of several wells from a variety of geographic areas with largely different conditions, illustrates this characteristic.

Further study determined that the basic plot shape was a reflection of changes in the conductivity of the formation fluids. This is shown in Fig. 2, where constant fluid conductivity trend lines have been added to a typical attenuation/porosity plot. This knowledge led directly to the idea of correcting the EPT log t-or shaliness by modifying Rw, proportionally. Although this was done successfully, a question was raised. Do other logs that react to the volume and conductivity of formation fluids also respond to dual waters?

Micro later o log and Induction Log Data

The familiar Pickett plot (log-log plot of conductivity vs. porosity) is a convenient form for making this evaluation because it allows a relatively pure look at the data.

Pickett plots using a density/neutron-based porosity were constructed with Micro later o log (Fig. 3) and induction (Fig. 4) log data.* Two distinct data concentrations could be seen, one associated with low gamma ray values and the other with high gamma ray values.

These plots have been enhanced with an illustration of a simple Archie-type transform of some known fluid conductivities by assuming that KR=1.0 and m=2.0 in the classic equations, FR=KR/om and Cw=FRCo, (Ro,=FRRw). The Cw values chosen reflect Rw, (Cw=30.0 mho. Rmf (Cw=1.0 mho), and the theoretical clay water conductivities for the existing temperature conditions.

JPT

P. 158^
Reservoir Simulation Using an Adaptive Implicit Method
Authors: Thomas G. W. , Thurnau D. H.
Published: December 2007

This paper deals with a new implicit method for reservoir simulation. Rather than provide a fixed degree of implicitness in every gridblock at every time step or iteration, the adaptive implicit method operates with different levels of implicitness in adjacent gridblocks. These levels shift in space and time as needed to maintain stability. Shifting is accomplished automatically without user intervention. The technique can be applied to any simulation problem involving N unknowns. The advantage is substantial reduction in computing time and storage requirements compared to fully implicit formulations, while still yielding unconditionally stable solutions.

The mathematical procedure involves labeling the implicit/explicit mix of unknowns and then composing the matrix problem. The latter is reducible as long as there is one or more unknowns to be computed explicitly; consequently, appropriate operations are performed to put it in reduced form. This leads to matrix equations of lower order than the original problem that are solved at less cost. We demonstrate each step of the mathematical procedure with an example.

Finally, applications to a three-phase coning problem and a three-dimensional (3D) Cartesian problem are presented. By using special displays we demonstrate the degrees of implicitness in each cell and how they shift in space and time during simulation. We also present information regarding the savings in computer time and storage compared with a fixed, fully implicit procedure.
Mobilization of Residual Oil Under Equilibrium and Nonequilibrium Conditions
Authors: Lam Andrew C. , Schechter Robert S. , Wade William H.
Published: December 2007

A microvisual study of residual oil mobilization that uses a relatively simple chemical system consisting of water, n-propanol, and cyclohexane is presented. Two different classes of experiments were performed to determine the sensitivity of the capillary number required to displace a particular residual oil globule from chemical equilibrium. It was found that under certain circumstances the capillary number required to mobilize the oil drop could be reduced greatly if the displacing phase contained more alcohol than it would in equilibrium with the trapped phase.

Experiments clearly demonstrated that spontaneous emulsification by a diffusion and stranding mechanism could not account for the differences between equilibrium and nonequilibrium capillary numbers. Experimental observations did correlate well with the development of interfacial turbulence (Marangoni effect). Variations that, according to theory, tended to enhance the level of interfacial turbulence between the equilibrium and nonequilibrium capillary numbers were observed. The importance of the Marangoni effect relative to laboratory oil recovery experiments is discussed.

A second class of experiments consisted of observing the displacement of residual oil globules that had been increased in volume (swollen) by mass transfer from a continuous phase flowing too slowly to displace the drop. Once the residual oil globule attained equilibrium with the continuous phase, the flooding velocity was increased until the swollen globule was displaced. Surprisingly, slightly swollen globules required a larger capillary number for mobilization than the original drop. Thus, the capillary number for swollen residual oil globules goes through a maximum as a function of the degree of volume increase. The precise position of the maximum varies for each globule since mobilization is a complex function of geometry.
Effect of Taxation on Valuation and Production Engineering
Authors: Breeding Clark W. , Herzfeld John R.
Published: December 2007

Introduction

Taxes are important in the evaluation of any investment. For example, the market price of a tax exempt municipal bond will usually be higher than the market price of a fully taxable industrial bond of equivalent interest rate and security. Similarly, the buyer of a business will consider the impact of taxes in determining its potential yield and payout. The timing and extent of capital improvement programs are also influenced by taxes. For example, the time of repayment and ability to repay purchase obligations will be materially influenced by the ability to deduct the cost of improvements through depreciation or depletion charges. The oil and gas industry is affected by certain special rules of taxation which tend to make tax considerations of paramount importance to the industry. Some of these specialized concepts will be discussed and their effect upon specific transactions will be examined.

Property Unit

If the land department of an oil company secures four 160-acre leases from four different landowners, thereby securing a 640-acre tract, the operating departments of the company would likely regard such a tract as a single property for most purposes. However, under income tax rules, the company is regarded as having four properties, even though 640-acre spacing might be required, absent an election to aggregate, which will be discussed presently. Property is defined by the Internal Revenue Code as "each separate interest owned by the taxpayer in each mineral deposit in each separate tract or parcel of land". This definition places emphasis on the concept of separateness whether it arises by reason of the nature of the interest owned by the taxpayer, the various deposits under the tract of land, or the number of tracts or parcels into which it may be carved. The types of interest which may be regarded as separate would refer to the kind of interest owned by the taxpayers such as a fee simple, working interest, royalty, or over-riding royalty, etc. Regardless of how or when acquired, each such interest would be regarded as a separate property for depletion purposes, except in certain very special circumstances. If several mineral deposits are under a single tract or parcel of land, each deposit is regarded as a separate property.
Applying Instantaneous Corrosion Rate Measurements To Waterflood Corrosion Control
Authors: Wright Charles C.
Published: December 2007

The recent availability of the instantaneous corrosion-rate measuring instrument developed by Pure Oil Co. has enabled a new approach to corrosion control. In the past either corrosion had to occur and be measured or the causes of corrosion known and measured to allow successful corrosion control. This paper shows the sensitivity of instantaneous corrosion-rate measurements to changes in operating conditions in a water flood. Response is immediate, thus allowing the plant operator to take prompt remedial measures before damage is done.

Introduction

The starting point for the corrosion-rate meter appears to be the work published in 1955 by Simmons, followed by a paper in 1957 describing experiments in which a small current was passed through a coupon immersed in a corrosive liquid. They found that the change in electrode potential per unit of current flow was apparently inversely proportional to the instantaneous corrosion rate of the coupon. This was followed, in 1958, by a paper on corrosion by Stem, who showed that there is a theoretical basis for this finding. The first practical application of polarization resistance measurements to solving corrosion problems was made by Marsh. Marsh proceeded from his early work and enlarged upon his earlier development of the electrical resistance probes for corrosion measurements. He developed a simple probe utilizing two electrodes of the same metal or alloy, thereby eliminating the need for reference electrodes and for precise knowledge of electrode potential data. In this new probe, Marsh applied a potential of 2/100 v across the two electrodes and then measured the current flow. In practice, the potential is applied for 5 to 15 seconds and the current flow is read. Then the direction of current flow is reversed by reversing the potential and the measurements repeated. Marsh calibrated his initial instrument by using two electrical resistance probes as the electrodes for his polarization resistance probe. The electrical resistance probes were used at the same time as a means of determining the actual amount of corrosion taking place. Marsh followed this with a paper in which he reported "The relative effectiveness of the inhibitor can be estimated from the corrosion rate of the electrodes as measured by the corrosion rate meter. Because the tests are quite rapid, variations in testing can be used to compensate somewhat for the artificial conditions employed in the test. Inhibitors highly effective under widely different conditions have been discovered by this technique".'

Principle of Operation

The principle of the corrosion meter may be explained as follows.

JPT

P. 269ˆ
Automation of an In-Situ Combustion Tube and Study of the Effect of Clay on the In-Situ Combustion Process
Authors: Vossoughi Shapour , Willhite G. Paul , Kritikos William P. , Guvenir Ibrahim M. , El Shoubary Youssef
Published: December 2007

A fully automated in-situ combustion apparatus supported by a minicomputer was designed, constructed, and tested.

Results obtained from four adiabatic dry combustion runs to investigate the effect of clay on crude oil combustion are reported. Sand mixtures of varying clay (kaolinite) content were saturated with crude oil and water. The fourth run was performed with amorphous silica powder in the sand mixture for comparison with clay results.

We concluded that the large surface area of the clays was a major contributor to the fuel deposition process. However, different oxygen utilization efficiencies obtained from both types of sand mixtures indicated that mechanisms controlling the combustion reaction also depended on the composition of the porous matrix.

A thermogravimetric analyzer (TGA) and a differential scanning calorimeter (DSC) were used to obtain kinetic data on the effects of kaolinite type clay on crude oil combustion. The addition of kaolinite clay or silica powder changed the shape of the crude oil TGA/DSC thermograms significantly, but sand had no effect. The major effect on DSC thermograms was a shifting of the large amount of heat produced from a higher to lower temperature range. Reduction of activation energy caused by the addition of kaolinite clay to the crude oil indicates both catalytic and surface area effects on combustion/cracking reactions.
Meren Field-The Geology and Reservoir Characteristics of a Nigerian Offshore Field
Authors: Poston Steven W. , Berry Peter , Molokwu Felix W.
Published: December 2007

The Meren field is located offshore Nigeria. The field contains 1.3 billion bbl original oil in place (OOIP) and may be classed as a major oil accumulation. The more landward-lying fault blocks within the field contain an increasingly greater preponderance of oil reserves to gas reserves. All field pays display evidence of the depositional process occurring contemporaneously with fault movement. Sand sections have a tendency to become magnified in the downthrown portion of a fault block. The reservoirs are composed of sandstone with minor accumulations of authigenic kaolinite. The amount of kaolinite within a particular sand is a major factor in determining the porosity and permeability. The high porosities and permeabilities and the ability of the reservoir rock to remain unaltered by the introduction of seawater should minimize many of the operational problems ordinarily coincident with the installation of a water-injection project in the Meren field. This study indicates the possibility of using a combination of well-log interpretation with laboratory analyses of sidewall cores to help determine the areal variation of porosity and permeability within a particular reservoir.

Introduction

The Meren field is jointly owned by Nigerian Natl. Petroleum Co. (NNPC) (60%) and Gulf Oil Co. (40%); however, the field is operated be Gulf Oil Co. (Nigeria) Ltd. (GOCON). Fig. 1 shows the location of the field, offshore Bendel State and approximately 25 miles northwest of the GOCON/NNPC Escravos River Tank Farm and Export Terminal. The water depth in the field varies from 48 to 60 ft. Fifty-seven wells have been drilled in the Meren field, three of which are dry holes. The field was discovered in 1965. Production began in Sept. 1968. As of July 1, 1980. the Meren field has produced 347,194,961 STB oil, 321,545,190 Mcf gas, and 10,123,132 bbl water. Cumulative recovery is 26% OOIP.

Performance analysis has shown that the majority of the reservoirs producing from the Meren field are being affected by minimal water influx. The reservoirs appear to be producing by a depletion-drive/gas-cap expansion mechanism. In 1978 GOCON and NNPC authorized a full-fledged feasibility study to determine the true worth of enhancing oil recovery from the Meren field. The first portion of the study ascertained reservoir configurations and their reservoir rock and fluid characteristics. The following segments were contained in this preliminary field definition study.

Geological Study

The Meren field was subjected to a complete geological study. All geological data were analyzed, and proper corrections were made to the original interpretations.

Core Analysis

The Meren 57 well was drilled and cored in late 1978 to confirm the results of the coring of the Meren 5 well in 1968.

JPT

P. 2095^
Miscible Drive Field Applications in the Bisti Pool
Authors: Brooks Robert E.
Published: December 2007

Introduction

The Bisti Lower Gallup oil pool, San Juan County, New Mexico, covers approximately 24,000 acres, is 24 miles long and 1.5 miles wide. The oil productive Lower Gallup formation is of Upper Cretaceous age, and is composed of alternating layers of sandstone, sandy shale, and shale. The reservoir is encountered at a depth of 4,900 ft and has an average gross thickness of 135 ft of which only 10 to 20 per cent will have a permeability greater than 1 md. The best developed sand follows the crest of the long, narrow sand bar.

An LPG miscible displacement pilot project was started in Aug., 1957, on a 40-acre five-spot in the upper zone of the Lower Gallup. In the pilot area the upper (producing) zone is a light grey, medium-grained, clean, well sorted sandstone with a porosity of 13 per cent, permeability of 100 md, and net pay thickness of 16 ft. The permeability varies from 400 to less than 1 md.

The stock-tank oil has a gravity of 38° API. Measured fluid properties at the bubble point pressure of 1,207 psia and reservoir temperature of 145°F are solution gas-oil ratio, 407 cu ft/bbl; formation volume factor, 1.26; oil viscosity, 0.7 cp; and gas viscosity, 0.015 cp. The flood is conducted at reservoir pressures slightly in excess of the bubble point pressure.

History of the Pilot

Early performance predictions indicated that the field primary recovery would be low because the reservoir is thin and tight, and operating under a solution gas-drive mechanism. The gas-driven LPG miscible displacement pilot project was recommended after studies of high pressure vaporizing gas drive did not indicate great benefits. The pilot consists of four producing wells spaced 40 acres apart with an injection well completed in the center of the four producers. The four pilot wells are the Sunray Mid-Continent Federal C wells No.1 and 2, British-American Marye No.1 and Phillips Hospah A No.1. Also participating in the project are EI Paso Natural Gas Products Co., Amerada Petroleum Corp. and Shell Oil Co., although they are not operating wells in the pilot area.
Fracture Penetration Through an Interface
Authors: Biot M. A. , Medlin W. L. , Massé L.
Published: December 2007

This paper presents a combined theoretical and experimental investigation of fracture penetration through an interface. The results have application to hydraulic-fracture containment in sandstone or limestone reservoir strata bounded by shale layers. Several simplifying assumptions and approximations are made. We assume that the interface separates dissimilar but adhering materials that are elastic to first order. We consider only differences in material properties and take stresses to be locally uniform. Approximations are made that reduce the fourth-order equation of plane strain elasticity to the second-order Laplace equation. Crack shape is taken to be sinusoidal and fluid leakoff is ignored.

Additional simplifying assumptions are made about the shape of the crack tip as it passes through the interface. Using a virtual work analysis, we derive a relation for internal fluid pressure required to extend the crack through the interface. This pressure is related to the equilibrium pressure needed to hold the crack barely open. A simple relation is obtained involving only the shear modulus and surface energy of the materials on either side of the interface.

The theory was tested in laboratory experiments with Plexiglas™/resin bonds. Test blocks of several configurations were used with various kinds of external loading. Cracks were initiated by applying grease pressure in thin notches. Pressures required to hold cracks in equilibrium were compared with those required to penetrate interfaces. Results were consistent with the theory within limits of precision in measuring surface energy. We conclude that the theory explains field observations of containment in a number of reservoirs that have been fractured hydrualically. However, practical value is limited by inability to estimate surface energies from logging or other wellbore data.