bluuebunny/crossref_metadata_2025 huggingface dataset:
Constitutive PtdIns(3,4,5)P3 synthesis promotes the development and survival of early mammalian embryos
Authors: Halet Guillaume , Viard Patricia , Carroll John
Published: December 2007

Mammalian preimplantation embryos develop in the oviduct as individual entities, and can develop and survive in vitro, in defined culture media lacking exogenous growth factors or serum. Therefore, early embryos must generate intrinsic signals that promote their development and survival. In other cells, activation of class I phosphoinositide 3-kinase (PI3K) is a universal mechanism to promote cell proliferation and survival. Here, we examined whether PI3K is intrinsically activated during preimplantation development. Using GFP-tagged pleckstrin homology domains to monitor PtdIns(3,4,5)P3 synthesis, we show that PI3K is constitutively activated in mouse preimplantation embryos. E-cadherin ligation promotes PtdIns(3,4,5)P3 synthesis at sites of blastomere adhesion at all cleavage stages. In addition, in culture conditions that promote autocrine signalling, a second pool of PtdIns(3,4,5)P3 is generated in the apical membrane of early stage blastomeres. We show that constitutive PtdIns(3,4,5)P3 synthesis is necessary for optimal development to blastocyst and to prevent large-scale apoptosis at the time of cavitation.
Formation and function of Weibel-Palade bodies
Authors: Metcalf Daniel J. , Nightingale Thomas D. , Zenner Helen L. , Lui-Roberts Winnie W. , Cutler Daniel F.
Published: December 2007

Weibel-Palade bodies (WPBs) are secretory organelles used for post-synthesis storage in endothelial cells that can, very rapidly, be triggered to release their contents. They carry a variety of bioactive molecules that are needed to mount a rapid response to the complex environment of cells that line blood vessels. They store factors that are essential to haemostasis and inflammation, as well as factors that modulate vascular tonicity and angiogenesis. The number of WPBs and their precise content vary between endothelial tissues, reflecting their differing physiological circumstances. The particular functional demands of the highly multimerised haemostatic protein von Willebrand Factor (VWF), which is stored in WPBs as tubules until release, are responsible for the cigar shape of these granules. How VWF tubules drive the formation of these uniquely shaped organelles, and how WPB density increases during maturation, has recently been revealed by EM analysis using high-pressure freezing and freeze substitution. In addition, an AP1/clathrin coat has been found to be essential to WPB formation. Following recruitment of cargo at the TGN, there is a second wave of recruitment that delivers integral and peripheral membrane proteins to WPBs, some of which is AP3 dependent.
Factor requirements for translation initiation on the Simian picornavirus internal ribosomal entry site
Authors: de Breyne Sylvain , Yu Yingpu , Pestova Tatyana V. , Hellen Christopher U.T.
Published: December 2007

The Simian picornavirus type 9 (SPV9) 5′-untranslated region (5′ UTR) has been predicted to contain an internal ribosomal entry site (IRES) with structural elements that resemble domains of hepacivirus/pestivirus (HP) IRESs. In vitro reconstitution of initiation confirmed that this 5′ UTR contains an IRES and revealed that it has both functional similarities and differences compared to HP IRESs. Like HP IRESs, the SPV9 IRES bound directly to 40S subunits and eukaryotic initiation factor (eIF) 3, depended on the conserved domain IIId for ribosomal binding and consequently for function, and additionally required eIF2/initiator tRNA to yield 48S complexes that formed elongation-competent 80S ribosomes in the presence of eIF5, eIF5B, and 60S subunits. Toeprinting analysis revealed that eIF1A stabilized 48S complexes, whereas eIF1 induced conformational changes in the 40S subunit, likely corresponding to partial opening of the entry latch of the mRNA-binding channel, that were exacerbated by eIF3 and suppressed by eIF1A. The SPV9 IRES differed from HP IRESs in that its function was enhanced by eIF4A/eIF4F when the IRES was adjacent to the wild-type coding sequence, but was less affected by these factors or by a dominant negative eIF4A mutant when potentially less structured coding sequences were present. Exceptionally, this IRES promoted binding of initiator tRNA to the initiation codon in the P site of 40S subunits independently of eIF2. Although these 40S/IRES/tRNA complexes could not form active 80S ribosomes, this constitutes a second difference between the SPV9 and HP IRESs. eIF1 destabilized the eIF2-independent ribosomal binding of initiator tRNA.
Mammalian 2′,3′ cyclic nucleotide phosphodiesterase (CNP) can function as a tRNA splicing enzyme in vivo
Authors: Schwer Beate , Aronova Anna , Ramirez Alejandro , Braun Peter , Shuman Stewart
Published: December 2007

Yeast and plant tRNA splicing entails discrete healing and sealing steps catalyzed by a tRNA ligase that converts the 2′,3′ cyclic phosphate and 5′-OH termini of the broken tRNA exons to 3′-OH/2′-PO4 and 5′-PO4 ends, respectively, then joins the ends to yield a 2′-PO4, 3′-5′ phosphodiester splice junction. The junction 2′-PO4 is removed by a tRNA phosphotransferase, Tpt1. Animal cells have two potential tRNA repair pathways: a yeast-like system plus a distinctive mechanism, also present in archaea, in which the 2′,3′ cyclic phosphate and 5′-OH termini are ligated directly. Here we report that a mammalian 2′,3′ cyclic nucleotide phosphodiesterase (CNP) can perform the essential 3′ end-healing steps of tRNA splicing in yeast and thereby complement growth of strains bearing lethal or temperature-sensitive mutations in the tRNA ligase 3′ end-healing domain. Although this is the first evidence of an RNA processing function in vivo for the mammalian CNP protein, it seems unlikely that the yeast-like pathway is responsible for animal tRNA splicing, insofar as neither CNP nor Tpt1 is essential in mice.
Comment—Cross-Brand Pass-Through: Fact or Artifact?
Authors: McAlister Leigh
Published: December 2007

Cross-brand pass-through implies that a retailer responds to wholesale promotional support from a target brand by changing the retail prices of competitive brands. Besanko et al. (2005) model a target brand's retail price as a function of its own and other brands' wholesale prices using 780 observations (15 price zones × 52 weeks) and take the many significant coefficients for other brands' wholesale prices that they find as evidence of cross-brand pass-through. Because price zones do not react independently to wholesale prices when they set a brand's retail price, Besanko et al.'s (2005) estimation overstates the number of independent observations by a factor of 15. When we correct for this overstatement of independent observations, we find that the number of stable, significant coefficients for other brands' wholesale prices is lower than one would expect by chance. We conclude that there is no evidence of cross-brand pass-through in the 11 categories analyzed by Besanko et al. (2005).
A Convex Optimization Approach to Modeling Consumer Heterogeneity in Conjoint Estimation
Authors: Evgeniou Theodoros , Pontil Massimiliano , Toubia Olivier
Published: December 2007

We propose and test a new approach for modeling consumer heterogeneity in conjoint estimation based on convex optimization and statistical machine learning. We develop methods both for metric and choice data. Like hierarchical Bayes (HB), our methods shrink individual-level partworth estimates towards a population mean. However, while HB samples from a posterior distribution that is influenced by exogenous parameters (the parameters of the second-stage priors), we minimize a convex loss function that depends only on endogenous parameters. As a result, the amounts of shrinkage differ between the two approaches, leading to different estimation accuracies. In our comparisons, based on simulations as well as empirical data sets, the new approach overall outperforms standard HB (i.e., with relatively diffuse second-stage priors) both with metric and choice data.
Supporting Real-Time Cognitive State Classification on a Mobile Individual
Authors: Dorneich Michael C. , Whitlow Stephen D. , Mathan Santosh , Ververs Patricia May , Erdogmus Deniz , Adami Andre , Pavel Misha , Lan Tian
Published: December 2007

The effectiveness of neurophysiologically triggered adaptive systems hinges on reliable and effective signal processing and cognitive state classification. Although this presents a difficult technical challenge in any context, these concerns are particularly pronounced in a system designed for mobile contexts. This paper describes a neurophysiologically derived cognitive state classification approach designed for ambulatory task contexts. We highlight signal processing and classification components that render the electroencephalogram (EEG) -based cognitive state estimation system robust to noise. Field assessments show classification performance that exceeds 70% for all participants in a context that many have regarded as intractable for cognitive state classification using EEG.
A Random Glance at the Flight Deck: Pilots' Scanning Strategies and the Real-Time Assessment of Mental Workload
Authors: Di Nocera Francesco , Camilli Marco , Terenzi Michela
Published: December 2007

Based on previous research showing the usefulness of spatial statistics in detecting randomness in the distribution of eye fixations, this study investigated the ocular behavior of professional pilots engaged in a simulated flight. The distribution of eye fixations was used as an indirect index of mental workload: Eye movements were recorded during the different phases (departure to landing) of a simulated flight and were analyzed using spatial statistics algorithms. Results showed sensitivity of spatial dispersion indices to variations in mental workload: higher during departure and landing, lower during climb and descend, and the lowest during the cruise phase. This finding provides additional evidence of the utility of fixations distribution as a real-time measure of mental workload and, consequently, as a trigger for adaptive automation.
Design of Functionalized PAMA Viscosity Modifiers to Reduce Friction and Wear in Lubricating Oils
Authors: Müller Michael , Fan Jingyan , Spikes Hugh
Published: December 2007

Polyalkylmethacrylates (PAMAs) are widely used as both viscosity index improvers and dispersant boosters in engine, hydraulic, and transmission oils. Since they are employed in a relatively high concentration in these roles, it is desirable that they be able to enhance other characteristics of a lubricant and, in particular, its boundary lubricating properties. A series of functionalized PAMAs have been synthesized that can adsorb from oil solution onto rubbing surfaces to produce thick boundary films. These films enhance lubricant film formation in slow speed and high temperature conditions and thus make a significant contribution to their lubricating ability. The current paper describes a systematic study of the influence of functionalized PAMAs on boundary lubrication performance. The high frequency reciprocating test rig (HFRR) was applied to investigate friction and wear under pure sliding. A new test method has been developed which allows wear to be monitored in a rolling and sliding contact based on the mini traction machine (MTM). This, in combination with other tests, is employed to investigate the influence of polymer architecture, functionality, concentration and molecular weight on friction and wear in a range of lubricant formulations. This enables the tailored design of polymers which offer low friction and wear properties.
Design, Construction, and Installation of Conventional Steel Jacket Platforms
Authors: Lee Griff C. , Andrews J. Connie
Published: December 2007

Construction of the first steel jacket-type offshore structure began in 1947, in shallow water, in the Gulf of Mexico. Both design and installation techniques have progressed to the point that a fixed platform now stands in a water depth of over 300 meters.

By today's standards, the early design calculations were rather crude. As electronic computers became available, more sophisticated analysis tools were developed. Still further enhancements have been developed in design technology to take into account the dynamic characteristics of both the load application and the structural response. Parallel improvements have also been made in the construction engineering phase of design which insures that the installation can be safely performed as planned. Improvements in fabrication and installation capability have kept pace with the developments in design technology. New, "third generation", large capacity derrick barges and pile hammers as well as construction techniques are now available which make the installation of large structures in rough water a routine procedure.

In all previously developed offshore areas, the fixed platform has proven to be the most dependable and efficient support for drilling and production operations. There is no reason why similar structures cannot be equally successful in the offshore waters surrounding the People's Republic of China.
Automated Production Systems
Authors: Hardy Ian J. , Wetzel Gordon P.
Published: December 2007

The Western Operating Area of the Prudhoe Bay field in Alaska gathers oil and gas from 17 remote well pad facilities, covering an area of 108 square miles. Three Gathering Centers, each capable of handling 300 MB/D of oil and 480 MMSCF/D of gas, pteprocess the oil before shipment via the Trans-Alaska pipeline.

The size of the field, its geographic location, and the "tight line" transportation system provide some challenging operational and control problems. These problems are identified showing how automation has been used to solve them. This includes the use of an integrated supervisory control system and a distributed process control system designed to meet the control needs of future production facilities as the field proceeds to ultimate development.
Simultaneous Characterization of Geological Shapes and Permeability Distributions in Reservoirs Using the Level Set Method
Authors: Villegas R. , Dorn O. , Moscoso M. , Kindelán M. , Mustieles F.
Published: December 2007

An important technique in modern reservoir management is the use of production data for the characterization of permeability distributions with more than one lithology from production data. A major difficulty which arises in these situations is that sharp discontinuities of permeabilities between these lithofacies need to be reconstructed at the same time with more smoothly varying profiles inside of them. So far, techniques have been developed which recover either the interfaces or a smoothly varying profile, but not both of them. Our group has developed recently a novel method for modelling and reconstructing geological shapes in reservoirs from production data. This method is based on a level set representation of the shapes. In our previous work1,2 we have assumed that the permeability distribution in the different regions of the reservoirs do not vary significantly such that they can be approximated by a constant value which was approximately known from prior information. In this paper we will present an extension of this new method which is able to recover at the same time the shapes of the different geological regions and variations of the permeability distribution in each of these regions. In each step of our new reconstruction technique the production data are used in order to calculate an update for the shape of the two lithofacies and at the same time a pixel-based correction of the parameter profiles inside of these regions. Only one simulation of a two-phase flow simulator and a corresponding adjoint simulator are necessary for calculating both updates. In our paper we will present numerical results in 2D for realistic situations of a water flooding process. We show that our method is able to reconstruct two lithofacies of complicated shape and the corresponding permeability distributions simultaneously from these production data.
Validity of Steady-State Upscaling Techniques
Authors: Jonoud S. , Jackson M. D.
Published: December 2007

Steady-state upscaling techniques are attractive because they are quick and simple to implement; unlike dynamic methods, there is no need for fine grid simulation and the upscaled properties are not case dependant. They are based on the assumption that either capillary forces (capillary equilibrium limit, CL) or viscous forces (viscous limit, VL) dominate flow. However, the reservoir conditions for which these assumptions are valid have not been clearly defined. It is generally supposed that the CL method is valid at ‘low’ flow rates over ‘small’ lengthscales, while the VL method is valid at ‘high’ flow rates over ‘large’ lengthscales. These qualitative criteria are difficult to properly apply and can be easily violated, yielding significant errors in predicted reservoir performance.

We have identified a comprehensive suite of dimensionless groups which can be used to define the validity of steady-state methods. The groups account for the effect of heterogeneity, as well as the other parameters which control the balance between capillary and viscous forces. Numerical simulations have been used to identify the range of values for these groups over which steady-state methods are valid. Our results yield a practical set of quantitative criteria which can be used to determine the validity of steady-state upscaling methods for a wide range of geological models. They capture the effects of capillary trapping and are valid regardless of fluid mobility, wettability or end-point saturation.

We test our criteria against three realistic models of small-to intermediate-scale geological heterogeneity. We find that the criteria do a good job of predicting the range of validity for each method, and are conservative in all cases, suggesting that if they are met then steady-state upscaling techniques can be applied with confidence, and may still be valid for slightly less restrictive conditions. However, in the models investigated, we find that the validity of the CL method is restricted to very low flow rates which are unlikely to be encountered in most production scenarios. This is because the CL method overestimates the amount of capillary trapping. In general, VL upscaling is valid over a much more reasonable range of reservoir flow rates.
Hydrodynamic Modelling of the Hydrocarbon Migration and Accumulation in the Lublin Basin
Authors: Zawisza L.
Published: December 2007

Analysis of pressure and water chemistry data from the Devonian and Carboniferous formations of the Lublin Basin indicates that two regional fluid flow systems are operating within this basin. The Devonian basin is the juvenile basin with compaction-induced centrifugal, lateral water movement (before invasion by meteoric waters), and may be classified as prospective. The Carboniferous basin is an intermediate basin with centripetal water movement, artesian properties and invasion of meteoric water.

In this paper author presents the hydrodynamic modelling of hydrocarbon migration and accumulation in the Lublin Basin, Poland. The pressure and water chemistry data have been used to identify hydrocarbon traps within the Devonian and Carboniferous sequences.
A New Continuous Guidance Tool Used for High Accuracy Directional Surveys
Authors: Camden David John , Gartner Jean-Eugene , Moulin Pierre Alexis
Published: December 2007

In recent years, it has become increasingly important to determine, with a high degree of precision, the bottom hole location and trajectory of a well. Optimum reservoir drainage from deviated wells drilled from a single platform; successful relief well positioning for blowouts; and the demands made to comply with ecological or environmental conservation, all depend on a high level of accuracy in measuring the geometric parameters of boreholes.

The Guidance Continuous (GCT*) Tool has been built to fill this need. It is a 92 mm diameter cased hole tool equipped with the most advanced guidance components on the market. Comparison tests have shown it to at least an order of magnitude better than similar guidance systems.

Computations of the well trajectory are carried out by real-time software and the CSU" surface computer can be used to generate all the required listings, plots and projections of the well in given planes. The gyroscope central to the device is mounted on a motorized inertial platform allowing two degrees of freedom and giving very high overall accuracy. Quality control features such as the "closure" - the horizontal distance between the starting point of the survey and the final point, at the same depth, on the return survey - are an integral part of the design. Finally, the GCT tool is self-calibrating and needs no preset geographical references.
Molecular Interpretation of Several Different Properties of Flow of Coiled Polymer Solutions Through Porous Media in Oil Recovery Conditions
Authors: Chauveteau Guy
Published: December 2007

A systematic laboratory study of the various mechanisms possibly acting on the properties of flexible polymer solutions flowing through porous media was performed in order to interpret at a molecular level the phenomena pieviously observed, such as dilatant behavior, hydrodynamic retention and the variations of both mobility and permeability reductions as a function of pore size and adsorption properties.

The bulk rheological properties were studied in non-inertial shear and partly elongational flows through channels having well-known dimensions. The dilatant behavior can be explained by the coil-slretch transition of macromolecules in elongational parts of flow. This stretching gives a detectable increase in viscous friction and thus the onset of dilatancy as soon as the product of Eouse relaxation time and maximum stretch rate is greater than 4. At higher stretch rates,the highly elongated state of macromolecules induces very high viscous friction, causing the strong dilatancy observed.In porous media, the shear predeformation of macromolecules before they arrive in elongational zones explains why the onset of dilatant behavior occurs at relatively lowef de-Pornation rates than in straight channels with varying cross sections.

Hydrodynamic retention Las been observed beyond the onset of dilatant behavior in systems having pore dimensions much greater than the molecular size. This hydrodynamic retention could be explained by the migration of macromolecules possibly induced by both non-uniformity of velocity gradient field and differences in entropy between the zones where molecules are stretched and those where they are still coiled.

In the absence of adsorbed layer effects, the relative apparent viscosity or mobility reduction in fine pores at low deformation rates is always less than the bulk relative viscosity and decreases with pore size. This phenomenon is due to the existence of a depleted layer near the wall. An analytical relation is proposed to calculate apparent viscosity as a function of pore size and polymer solution characteristics.

In presence of adsorption at the pore wall, the maximum permeability reduction can be calculated by assuming the existence of an impermeable adsorbed layer, the hydrodynaeiic thickness of which is slightly hi^hèy than twice the gyration radius of the macromolecules. Thus, the permeability reduction is relatively slight in the absence of microgels at low flow rates, but increases at high flow rates, which contributes to increase the overall dilatant beiiavior. The ratio between mobility and permeability reduction at low flow rates is always less than the relative viscosity and decreases with pore size, which shows the existence of a depleted layer above" the adsorbed polymer,
Microemulsion Rheology: Newtonian and Non-Newtonian Regimes
Authors: Bennett Karl E. , Davis H. Ted , Macosko Chris W. , Scriven L. E.
Published: December 2007

Viscosity measurements are reported for micro-emulsions formed with pure and commercial surfactants. Approximate viscosities were measured with the multiphase rolling ball viscometer. Viscosities as functions of shear rate were measured on a cone-and-plate rheometer with an environmental chamber designed to control both temperature and evaporation.

At a fixed shear rate or shear stress, microemulsion viscosity often goes through two maxima as the salinity of the mixing brine increases and the microemulsion passes from a water-continuous to an oil-continuous phase. Microemulsions near these maxima were found in the present study to exhibit non-Newtonian behavior: under shear their viscosity decreases by as much as a factor of six. Away from the maxima, microemulsion appeared to be substantially Newtonian.

Shear-history effects were observed for several microemulsions even though temperature, environment and experimental procedure were carefully controlled.
Improving the Injectability of High Salinity Brines for Disposal or Waterflooding Operations
Authors: Raber Ellen , Thompson Robert E. , Smith Floyd H.
Published: December 2007

This work is part of a study conducted by Lawrence Livermore National Laboratory (LLNL) to improve the performance of brine injection wells at Gulf Coast Strategic Petroleum Reserve Sites. Our involvement established that granular media filtration, when used with proper chemical pretreatments, provides an effective and economical method for removing particulates from hypersaline brines. This treatment allows for the injection of 200,000 B/D with significantly increased well half-lives of 30 years.
The Effects of Weight Material Type and Mud Formulation on Penetration Rate Using Invert Oil Systems
Authors: Rupert J. Paul , Pardo Carlos W. , Blattel Steven R.
Published: December 2007

The penetration rates of invert oil mud systems in Mancos Shale have been measured using the full-scale wellbore simulator at the Drilling Research Laboratory. Experimental parameters were 1.) weight material type - high specific gravity (ilmenite) vs conventional (barite); 2.) fluid formulation - low colloid type (relaxed filtrate) vs conventional (low filtrate) and 3.) bit type - synthetic diamond insert blank vs conventional (three-cone roller). In addition to laboratory data, field case history data for corresponding systems have been studied. Maximum penetration rates were observed for the minimum solids system, especially when used in conjunction with the synthetic diamond insert bit.
Numerical Simulation of Gas Injection in Oil Reservoirs
Authors: Utseth Rolf H. , MacDonald Robert C.
Published: December 2007

Modeling of gas injection into an undersaturated oil reservoir using current simulation technology relies on the validity of assuming instantaneous equilibrium between the oil and the gas phases. This assumption makes the calculated performance highly sensitive to the size of the grid blocks. In particular, the calculated breakthrough time of the injected gas is underestimated. This is primarily due to the equilibrium assumption that requires the gas to saturate the oil in each individual grid block before flowing to the next block.

A method is presented that treats the transient resolutioning of gas in oil within the framework of a practical reservoir simulation model. The inclusion of nonequilibrium mass transfer requires that the simulator include one mass balance equation for each component in each phase. A heuristic mass transfer model that governs the amount of gas transfered the oil phase is described. Parameters to the heuristic mass transfer model are determined from considerations of formation geology and the diffusion-convection characteristics of the hydrocarbon reservoir system.

The results from the simulation model were compared to solutions obtained by conventional variable bubble-point models, and it was found that the performance, as estimated by the conventional simulators, is highly sensitive to the thickness of the blocks used to represent the reservoir. In order to verify the solutions obtained by the proposed model, comparisons were made to runs made with a high resolution reservoir model including both diffusion and convection effects. It was shown that the heuristic model relating the interphase mass transfer to the composition of the phases, is capable of efficiently simulating the gas injection process.
Co-Generation: A New Energy System to Generate Both Steam & Electricity
Authors: Carraway Paul M. , Kloth Terry L. , Bull Autry D.
Published: December 2007

Tenneco has become increasingly active in exploring the use of new oil field methods for generating energy. One of the methods is the co-generation of both steam and electricity in conjunction with thermal oil production operations in the Kern River Field in California.

This paper discusses the installation and operation of a co-generation system at Tenneco's Fee "C" Lease, whereby hot combustion gas from a turbine fueled by gas or lease crude will be used to generate steam for enhanced recovery, with the same turbine providing the power to generate electricity for sale to a utility. It will summarize the history of the project, some of the contractual requirements, the physical layout of the system, component descriptions, environmental considerations, and the composition of the final system.
Analytical and Experimental Investigations of Rock Cutting Using Polycrystalline Diamond Compact Drag Cutters
Authors: Swenson Daniel Vernon , Wesenberg Donald L. , Jones Adrian K.
Published: December 2007

The development of analytical techniques describing rock fracture during drilling would make possible a more rational approach to the design of drills and bits. In this paper we describe progress toward this goal based on finite element and experimental investigations of the rock cutting process for a single drag bit. The material model used for rock in the analysis includes fracturing due to both tensile and shear stresses. Results capture the essential features of drilling observed in the laboratory and indicate expected differences between unconfined laboratory tests and downhole drilling.
Instrumented Diamond Bit Testing Defines Pressure Drops and Hydraulic Distribution While Drilling at Simulated Depth in Shale
Authors: Tibbitts Gordon A. , Black Alan D. , Walker Bruce , Williams C. Ray
Published: December 2007

Two conventional 7-7/8 inch diameter natural stone surface set diamond bits were instrumented and used to drill shale in controlled laboratory tests at simulated conditions. The designations assigned to these bits in accordance to the International Association of Drilling Contractors are D333 and D323. The D333 bit is recommended for soft to medium formations whereas the D323 bit is recommended for medium to medium hard formations. Each bit has a different hydraulic design. The D333 is a radial flow design, whereas the D323 has a forced flow or "feeder-collector" hydraulic design.

Miniature pressure transducers were mounted at different locations on the bit crowns. While drilling under a wide range of simulated conditions, output from these transducers were recorded. From this data, an understanding of the magnitude and distribution of pressures at the bit face was obtained. An analysis of the data showed that a substantial amount of hydraulic energy is expended at or near the crowfoot or center of the bits. Also, an estimate of pump-off force (or hydraulic lift) as a function of pressure drop was obtained from the pressure distribution data. The work presented in this paper was sponsored by the Department of Energy, Office of Fossil Energy, Bartlesville Energy Technology Center in Bartlesville, Oklahoma.
A Steady-State Technique for Measuring Oil-Water Relative Permeability Curves at Reservoir Conditions
Authors: Braun Edward M. , Blackwell Robert J.
Published: December 2007

A steady-state technique for measuring oil-water relative permeability curves is presented. The technique allows measurements to be made on preserved core samples at reservoir temperature and pressure, using reservoir fluids. Live oil and brine are circulated simultaneously through the core in a closed system, and relative permeability data are taken when conditions in the core have stabilized. A series of five to ten flow rate ratios is normally used, providing data at saturations ranging from irreducible water to residual oil. Saturations are determined by monitoring the oil content of a high-pressure oil-water separator in the system.

The technique is particularly useful for heterogeneous cores and cores with mixed wettability, where dynamic displacement tests can give inaccurate relative permeability data. The use of reservoir conditions and live fluids is preferred because the true wettability of reservoir rocks may not be preserved in tests performed with dead crude or at room temperature.

Data is presented which demonstrates the application of this steady-state technique to the study of relative permeability hysteresis.
The Underground Natural Gas Storage in the FR Germany as a Result of the Increasing Energy Demand
Authors: Lindemann Norbert W. B. , Carlson Uwe
Published: December 2007

Over the past 12 years the natural gas consumption of the Federal Republic of Germany increased from 8 × 109 m3 to 60 × 109 m3. To date approx. 70 % of this quantity is imported. Imports, however, require more or less constant delivery rates. For the compensation of fluctuations in seasonal demand adequate storage capacities must be provided. Underground storages have been constructed since about 1950 but their capacities are still far behind the rapidly increasing demand. The distribution of existing storages and those under construction are described, considering the trend of natural gas consumption during the recent past as well as the energy economical prognosis at about 9 × 109 m3 and the necessity for future construction of new storages shown.
Comparison of Two Phase Liquid Holdup and Pressure Drop Correlations Across Flow Regime Boundaries for Horizontal and Inclined Pipes
Authors: Arya Atul , Gould Thomas L.
Published: December 2007

During the last decade the interest in two-phase flow through horizontal and inclined pipes has increased considerably. Design engineers are primarily concerned with the calculation of pressure drop in two-phase lines and prediction of liquid holdup (in-situ liquid volume fraction), in order to size flow lines and calculate slug catcher size. These calculations are also important for the design of surface facilities such as pumps, compressors and separators.

Due to the complex nature of the different flow patterns which exist in two-phase flow, very few theoretical mechanistic models have been developed. However, a large number of empirical correlations are available in the literature to calculate pressure drop and liquid holdup. Of this large number, only a few pressure drop correlations compute holdup, friction and acceleration gradients based on the flow patterns within the pipe1, 3, 4, 5, 6. Once the correct flow pattern is determined at a specified flow rate, pressure and temperature, the appropriate holdup and friction correlations are evaluated for the corresponding flow regime. The method for calculating the acceleration pressure gradient also depends on flow regime in some cases.

LIQUID HOLDUP AND PRESSURE DROP CORRELATIONS

Equations describing the pressure drop of a two-phase system are generally developed based on a single flow equation representing homogeneous mixture properties. The general pressure gradient equation is given as:
Transient Pressure Analysis: Finite Conductivity Fracture Case Versus Damaged Fracture Case
Authors: Cinco-Ley Heber , Samaniego-V. Fernando
Published: December 2007

This work presents the basic pressure behavior differences between a finite conductivity fracture and different types of damaged fractures.

Two kinds of fracture damage conditions are studied: a) a damaged zone around the fracture, and b) a damaged zone within the fracture in the vicinity of the wellbore. The first case is caused by the fracturing fluid loss in the formation and the last case is originated by crushing, embedding or loss of propant within the fracture in the vicinity of the wellbore.

This paper emphasizes that although finite fracture conductivity and fracture damage condition are both flow restrictions, their effects on transient pressure behavior are quite different at early time.

Type curves and both linear flow and bilinear flow graphs can be used to identify different cases when applied properly.
Cleanup of Groundwater Contaminated by Underground Coal Gasification
Authors: Raber Ellen , Thompson Robert E. , Smith Floyd H. , Duval Virgil L.
Published: December 2007

Bench scale laboratory experiments have confirmed the high adsorption capacity of bituminous activated carbon for the removal (>99.9%) of organic contaminants found in groundwaters associated with underground coal gasification (UCG) sites. Based upon recent laboratory and field interpretations, engineering designs are presented for the surface treatment of groundwater contaminated by UCG operations. A methodology is suggested for consideration of other unconventional in situ treatments.
SALM Installation in Santa Barbara Channel
Authors: Hofferber John E. , Masnada Dan A. , Deacon Nancy A. , Wolfram W. Robert
Published: December 2007

Oil and gas production has been underway in Exxon's Hondo Field since April 1981. The field is being developed using a 945-foot drilling and production platform, the Hondo Platform, and an offshore storage and treating vessel, the Exxon Santa Ynez. The dedicated 50,000 dwt vessel is moored to a single anchor leg type production riser which provides the connection to the three subsea pipelines and a power cable from the Hondo Platform. This paper presents the installation techniques used to install the Single Anchor Leg Mooring.
Evaluation and Development of Cement Systems for Geothermal Wells
Authors: Nelson Erik B. , Eilers Louis H. , Spangle Lloyd B.
Published: December 2007

Results of a three-year study concerning the cementing of geothermal wells are reported. The U.S. Department of Energy (DOE) funded research included some specific tasks: (1) determination of properties an adequate geothermal well must possess; (2) thorough evaluation of current high-temperature oilwell cementing technology in a geothermal context; and (3) recommendation of specific cement systems suitable for use in a geothermal well.
Deep Well Disposal of In-Situ Uranium Wastewater in the Southern Duval Mineral District
Authors: Jones Thomas A.
Published: December 2007

Eight of the ten in-situ uranium mines operating in the Southern Duval Mineral District are utilizing deep well disposal for production, process, and restoration wastewaters. Seven disposal wells are currently in operation with an additional four wells proposed.

The masssive sands of the Eocene Yegua Formation form an excellent disposal reservoir confined by the thick shales of the Jackson Group. The large areal extent and uniform reservoir properties of the Yegua Formation contribute to the successful application of deep well disposal throughout the District.

The high density of abandoned oil and gas wells is a problem with deep well disposal in this area; however, the presence of these abandoned wells does not preclude the use of deep wells for disposal. Problems presented by these "artificial penetrations" of the injection zone can be minimized by judicious well site selection and by careful selection of the well completion interval. Thorough data research of surrounding wells is fundamental in optimizing the injection well design and location.

The Southern Duval Mineral District is characterized by geology having the necessary requirements for proper wastewater disposal associated with in-situ uranium mining. Deep well disposal technology has been developed to meet the specific requirements of the Southern Duval geology, and this technology is continually being refined.
A Framework for Exploration and Production in Developing Countries
Authors: Ait-Laoussine Nordine , Miller Norman W. , Parra Francisco R.
Published: December 2007

Developing countries outside the OPEC Area are faced today with an urgent need to develop their indigenous energy resources and, in particular, their hydrocarbons. These are of key importance to net oil importers and small net exporters alike if their economic development is to continue at a satisfactory pace. In the past, governments have concentrated on structuring their exploration and production agreements in such a way as to secure for themselves most of the economic rent or windfall profits that result from large oil discoveries, and this has meant that exploration for the smaller fields has been seriously inhibited. There is a need now to structure E+P agreements so that they combine the governments' goal of capturing the economic rent on large discoveries with encouragement to explore for and develop the smaller fields which, in many countries, would make a significant contribution to the energy economy. The present paper puts forward a new framework agreement to accomplish these twin goals in a practical manner. It recognizes and builds into the agreement the fundamental distinction between the exploratory and development phases, and ties the contractors' reward to the financial rather than the physical performance of the field.
The HEP (Hydraulic, Electronic, Pneumatic) Pumping Unit: Performance Characteristics, Potential Applications, and Field Trial Results
Authors: Jesperson Paul J. , Laidlaw Robert N. , Scott Richard J.
Published: December 2007

The HEP pumping unit which is the result of a five year development program by Canadian Foremost Ltd., constitutes an alternative to the familiar beam pumping unit as a means of transferring energy from the prime mover to the sucker rod string of a pumping well. This paper addresses some basic concepts which are part of the HEP system design and will describe some of the resultant unit performance characteristics. The potential for enhancement of pumping well operations utilizing the high degree of control over rod string motion attainable with the HEP system, is discussed together with the results of a number of field trials in the Lloydminster area and some plans for further unit evaluation and development. A lift capacity comparison with conventional beam pumping units is also included.
Recovery of Retrograde Condensed Liquid by Gravity Drainage
Authors: Castelijns J. H. P.
Published: December 2007

A compositional model has been developed for calculating the recovery of retrograde condensate by means of gravity drainage. The model is an extension of the one-dimensional gas-oil gravity drainage theory in that it includes the effects of retrograde condensation and revaporisation. The model has been applied for the condensate-rich gas cap of the Afam F5.00 reservoir in Nigeria. It has been found that a substantial amount of condensate will accumulate at the gas/oil contact: over 5% of the gas cap's hydrocarbon pore volume after 10 years of production, increasing to almost 10% after 20 years. At the end of the reservoir's productive life, the average condensate saturation left behind in the gas cap will be some 3%. Hence, any pressure maintenance requirements in the reservoir will be dictated by oil shrinkage considerations rather than by the need to reduce liquid losses in the gas cap.
Steam Flooding: Treatment And Control Of Injection Fluids
Authors: Woods G.A.
Published: December 2007

Publication Rights Reserved

This paper is to be presented at the California Regional Meeting in Los Angeles, Calif., Nov. 5–6, 1964, and is considered the property of the Society of Petroleum Engineers. Permission to publish is hereby restricted to an abstract of not more than 300 words, with no illustrations, unless the paper is specifically released to the press by the Editor of the JOURNAL OF PETROLEUM TECHNOLOGY or SOCIETY OF PETROLEUM ENGINEERS JOURNAL is granted on request, providing proper credit is given that publication and the original presentation of the paper.

Discussion of this paper is invited. Three copies of any discussion should be sent to the Society of Petroleum Engineers office. Such discussion may be presented at the above meeting and considered for publication in one of the two SPE magazines with the paper.

With the constant increase in demand for oil products and decrease in domestic reserves, the need to develop secondary methods of oil recovery in existing fields becomes increasingly important. Many depleted or partially depleted fields have been brought back into production by such methods as water flooding, steam or hot water flooding, and in-situ combustion or fire flooding. Though once considered relatively exotic and new in concept, these techniques have accounted for a great increase in oil recovery from fields once considered exhausted.

The average recovery expected with cold water flooding is considered to be about 20% of the oil in place after primary production, whereas a recovery of 60% or more can be expected from a well operated steam flood.

As with other oil production methods certain problems are involved. Of paramount importance is the proper treatment and control of injection fluids to minimize equipment and formation damage.

It is generally true that water in oil recovery areas is not of the best quality and thus when steam or hot water flooding is employed as a secondary method of oil recovery, treatment of the water can be of significant importance. Such treatment must be engineered for each flood so as to assure freedom from scale and corrosion problems in the steam or hot water generators and piping, as well as plugging in the flood. Boilers employed in this type of operation are frequently of high heat exchange design, requiring high quality feedwater.

Various approaches of Water treatment are discussed including external as well as internal conditioning.
An Interactive Production Forecasting And Economic Evaluation System
Authors: Hennigan H. W. , Canon M. W. , Ziara B. A.
Published: December 2007

This paper describes an interactive, conversational model for production forecasting and economic evaluation. The system is designed to provide ‘Menu Selection’ at each branching point to allow the project analyst a choice of procedures for the program under study. The production forecasting capabilities range from the use of existing batch mode programs which employ reservoir engineering techniques applicable to various reservoir producing mechanisms to the use of decline curve procedures, curve fits of historical data plus extrapolation using an appropriate decline curve method or extrapolations of historical data based on the user's engineering judgment.

The system includes prompting, data preparation aids, and HELP commands for detailed explanations of data requirements and calculation procedures. Access to temporary and permanent data bases, or input of selected data and ability to examine intermediate results between discrete steps in the calculation sequence are provided. Optional depreciation and tax procedures include those needed for U.S., U.K., Norway, Indonesia, etc. Also available are escalation methods, sensitivity analysis, composite and difference cases, optional formats for result summaries and case detail, graphical video display and/or hard copy of selected output. Access to the data bases for storage of input data and results can be controlled with optional levels of security.

All procedures meet internal standards with respect to computational methods for reservoir engineering and accounting methods for tax and finanical basis economics evaluation. Results include all of the parameters normally used in economics analyses.
Selection of Artificial Lift Method
Authors: Neely Buford , Gipson Fred , Clegg Joe , Capps Bill , Wilson Phil
Published: December 2007

This paper summarizes the opening remarks of the panel members on a panel discussion of "Selection of Artificial Lift Method". This is not a co-authored paper in the normal sense. It is a paper with five sections, each section independently authored by a panel ember.