bluuebunny/crossref_metadata_2025_split huggingface dataset:
Capillary Desaturation in Unconsolidated Beads
Authors: Bethel F.T. , Calhoun John C. 
Published: April 2012

Abstract
Glass beads have been surface treated with Dri-film to render them oil wetby n-octane to varying degrees, and capillary desaturation curves have beendetermined by the restored state method. The desaturation curves show aregularity of increasing displacement pressures as the oil wetness increases.This has been used to compute apparent contact angles between n-octane andwater on glass. The family of desaturation curves also shows a regularcrossover, such that the residual wetting liquid saturation values are inreverse order to the displacement pressures. A semi-logarithmic variation isshown between the apparent contact angle and the residual saturation. Thedesaturation data are interpreted to mean that the wetting liquid ceases to bea continuous phase within individual pores before the capillary pressure can beraised sufficiently to force out the wetting phase completely. The saturationof wetting liquid at which this break in liquid continuity occurs is higher asthe oil wetness decreases.

Introduction
The petroleum industry has for some time been using measurements ofcapillary pressures on porous media for research correlations and engineeringcalculations. It has been generally recognized that the capillary desaturationcurve reflects the character and arrangement of the pores within the media andthe distribution of fluids within the pores. Methods have been proposed forcomputing pore size distributions, tortuosity factors, and relativepermeabilities from capillary desaturation data.
There is little doubt that the interactions between porous rocks and theircontained fluids resulting from surface forces play a dominant role indetermining the magnitude and direction of capillary pressure measurements.There have been attempts to introduce as variables two quantities - interfacialtension and contact angle - generally used to characterize surface forces, butin spite of the wide interest in these quantities as important variables, fewdefinite conclusions have been drawn concerning their qualitative orquantitative significance.

Interfacial Tension
The interfacial tension appears in a capillary pressure function given byLeverett for correlating capillary desaturation type curves. Use of theinterfacial tension in this function seems to be justified by other experimentsreported. Apparently, interfacial tensions have little bearing on wetting phaseresidual by desaturation.
T.P. 3639
Gas Storage in the Playa Del Rey Oil Field
Authors: Riegle John 
Published: April 2012

Abstract
To date, utility company underground storage of gas has generally beenrestricted to depleted dry gas fields. The Playa del Rey project is probablythe first to successfully store gas in a partially depleted oil reservoir withthe recovery of large volumes of gas at high rates as the main objective. Oilrecovery has been a secondary consideration.
Problems encountered unusual to those of storage in a dry gas zone were:the removal and retardation of formation of emulsion,the up structuremovement of fluid during withdrawal periods which formed fluid blocks, andreservoir shrinkage resulting from encroachment of edgewater.
The solution of these problems as outlined in the paper has resulted inincreasing the withdrawal rate from the original design capacity of 4,000 Mcfper hour to the current 10,000 Mcf per hour. Additional increase is anticipatedas the operations continue.
Migration, reservoir performance, operational procedure and a historicalrecord are included to make this a resume of the project from its war-timeinception in 1942 to the first of 1952.

Introduction
The Playa del Rey underground gas storage project is probably the firstproject in which gas has been stored in a partially depleted oil reservoir, with the recovery of large volumes of gas at high rates as the main objectiveand the recovery of oil a secondary consideration. Problems unusual to those ofstorage in dry gas zones have made this a pioneer endeavor.
The total storage capacity of approximately 1,500,000 Mcf of this reservoiris small in comparison with other underground gas storage projects. However, bystudy and experiment the deliverability into transmission lines, operating atpressures in excess of 150 lbs., has been nearly tripled in the past threeyears to the current 10,000 Mcf per hour rate, without the life of compression.It is anticipated this rate will gradually increase as additional fluid isremoved from the formation.

Location and History
Playa del Rey is located on Santa Monica Bay about two miles south of thebeach community of Venice and 15 miles southwest of the center of the City ofLos Angeles. Fig. 1.
T.P. 3669
Effect of Quick-Freezing vs Saturation of Oil Well Cores
Authors: Kelton Frank C. 
Published: April 2012

It is perhaps not widely realized that extraction and saturation processescarried out on oil well core samples alter the properties of these samples tovarying degrees. On the other hand it is felt by some that quick-freezing ofcore samples increases their permeability and porosity significantly.Accordingly, laboratory tests were carried out on 49 pairs of horizontallyadjacent samples in order to differentiate between the effect of quick-freezingper se on permeability and porosity of the samples, as distinguished from theeffect of the identical saturation treatment on permeability and porosity ofthe companion samples. Also, additional field data were obtained on comparisonof frozen vs unfrozen companion samples.

Laboratory Investigation of Freezing vs Saturation Effects

Procedure
The samples used in these tests were two-cm cubes cut in horizontallyadjacent pairs from cores from eight Gulf Coast and Mid-Continent wells, whichcores had not previously been frozen. These samples were extracted with carbontetrachloride, dried, and air permeabilities run in the conventional manner.They were then evacuated and saturated with brine of 25,000 ppm sodium chloridecontent, and porosities determined by gain in weight. The samples werepartially desaturated by evaporation down to an average brine saturation of 68per cent. One sample from each pair was quick-frozen by covering with dry iceafter wrapping in a single layer of paper, and allowed to remain frozen forabout two hours; the companion sample from each pair was not frozen. Afterthawing the frozen sample, all samples were immersed in tap water overnight inorder to leach out most of the brine. Air permeabilities were re-run, and thesamples were again saturated with brine to determine a second porosityvalue.
For purposes of averaging of data, the samples were grouped according tofour permeability ranges, from 0 to 10, 10 to 100, 100 to 1,000, and 1,000 to3,840 md. Average permeability and porosity changes for the frozen vs theunfrozen adjacent samples are shown in Table 1.

Discussion
As may be seen from Table 1, the averages of the per cent permeabilityincreases for the quick-frozen samples ranged from 3.8 to 12.9 per cent amongthe four permeability groups.
T.N. 151
Comments on Capillary Equilibrium
Authors: Jones-Parra J. 
Published: April 2012

In previous Technical Notes, W. R. Rose and W. Purcell have discussed thecapillary pressure data presented by Welge. Welge obtained capillary pressurecurves of the imbibition type in which it was necessary to apply to theapparent wetting phase a greater pressure than that of the non-wetting phase tocomplete the cycle and reduce the non-wetting phase saturation to low values.Rose suggests in his Note that conditions of equilibrium could not haveprevailed, since the non-wetting phase pressure must always be the greater.Purcell in his Note, proceeds to postulate a pore system consisting of a seriesof "holes in a doughnut," in which he contends that under equilibriumconditions it is necessary to resort to negative capillary pressures beforesignificant wetting phase displacement can take place. There is a remarkablesimilarity between the shape of the capillary pressure curve calculated byPurcell and those measured by Welge.
It is the purpose of this Note to show that, because Purcell neglected toaccount for the behavior of the residual wetting phase saturation, his systemwas not in equilibrium during imbibition; and, furthermore, that if his systemhad been in equilibrium, negative capillary pressures would not have beenpossible.
In Purcell's pore system, the residual wetting phase will form pendularrings at the interstitial spaces existing somewhere within the system, forexample, such as those spaces between "doughnuts" as shown in Fig. 1.The true capillary pressure is that across the pendular ring interface, and forthe system to be in equilibrium the pressure drop across all interfaces must bethe same, including that across the interface in the tight pores A of diaphragmB (Fig. 1). As the pressure across the cell is reduced, the advancing interfacewill move into the pore from the diaphragm, but at each pressure, the curvatureof the pendular rings must be the same as that of the advancing interface ifequilibrium is to prevail. Since equilibrium conditions are the basis for theentire argument, it follows that pendular rings must grow as wetting phaseenters the pore, that is, as the pressure across the cell is lowered. InPurcell's calculated curve, the residual wetting phase saturation remainsconstant as the capillary pressure decreases. Thus, his curve does notrepresent an equilibrium process.
T.N. 152
Determination of Graphite in Drilling Mud
Authors: Jones Frank O. , Lummus J.L. 
Published: April 2012

Abstract
A field procedure for determining graphite in drilling mud is presentedwhich is sensitive to 0.25 lbs/bbl and accurate to 20 per cent. The method, utilizing oil flotation principles, is suitable for use in all oil-free waterbase muds except those containing lignosulfonates, lignites, or surface activeagents.

Introduction
Graphite was proposed as a drilling lubricant as early as 1940, but has notbeen used extensively until recently. Graphite has been substituted for oil incertain instances to avoid oil contamination of core samples since it has beenfound that graphite does not interfere with routine core analysis.
A major difficulty in using graphite is the lack of a satisfactory field testfor determining the concentration of graphite in mud.

Discussion of Method
Several possible methods of analysis were investigated, including chemicalseparation, density fractionation, radioactive tracers, and oil flotation. Theinvestigation indicated that a satisfactory method for field use could bedevised using an oil flotation method. It was found that toluene shaken with ahighly diluted mud sample would recover sufficient graphite to be apparent inthe oil phase. Refinement and standardization of technique made it possible todetect as little as 0.25 lb/bbl graphite and to estimate graphite content towithin 20 per cent by using a visual comparison method.
The test is limited to oil-free water base muds. Quebracho, phosphates, orbarytes in the mud do not interfere with the test but surface active agents, lignosulfonates, and lignites evidently render the graphite water-wet so thatnone may be recovered by oil-flotation.
T.N. 185
An Explanation of the Yuster Effect
Authors: Scott P.H. , Rose Walter 
Published: April 2012

Recent papers by S. T. Yuster have called attention to the largely ignoredconcept that there will be a transfer of viscous forces across fluid-fluidinterfaces during the flow of immiscible fluid phases through porous media.This leads to the implication that the relative permeability vs saturationfunction, as applied to each of the fluid phases of the system, will in someway be dependent on the viscosities of all the other fluid phases which arecontiguous to the flowing fluid of interest. In fact, Yuster has selected andanalyzed the properties of a capillary-tube model of the reservoir-prototypeflow systems and concludes from his studies that relative permeability valueswill be very markedly influenced by the viscosity ratio in two-phase systems.On the other hand, relative permeability data have been reported in theliterature for more than 20 years; and where these data are consistent at all, they consistently show no dependence on viscosity ratio (cf. chapter 7 ofMuskat for a resume of past experimental work). This paradoxical situation hasprompted us to re-evaluate Yuster's work.
The major flaw we find has to do with the properties of the model Yusteremployed to give qualitative support to his predictions. This model isdefective in that important surface area parameters characteristic of theprototype-reservoir flow system have not been pro pertly scaled. Fig. 1 showshow we believe Yuster's model should be modified to circumvent this difficulty.It depicts the capillary tube of radius R and length L, comprised of twoelements in series. The first part of length, Li has the nonwetting phaseflowing centrally out to a radius distance r, where an interfacial boundaryexists with the wetting phase which flows in the concentric annular space ofthe tube.
T.N. 192
The Effect of Overburden Pressure on Relative Permeability
Authors: Fatt I. 
Published: April 2012

Laboratory relative permeability data on reservoir rock are obtained onsamples which are not subjected to overburden pressure during the permeabilitymeasurements. These data are then used for calculating the performancecharacteristics of reservoirs in which the rock is under the pressure of theoverburden. Recent observations have shown that the permeability and porosityof reservoir sandstones are decreased by application of overburden pressure.These observations led us to a study of the effect of overburden pressure onthe relative permeability characteristics of sandstones.
A previous note from this laboratory showed that overburden pressure, simulated by applying hydraulic pressure to the outside of a plastic mountedcore, caused a reduction in permeability of the core by as much as 50 per centat 10,000 psig. In a multi phase fluid flow system, the relative permeabilityat a given saturation will change if the permeability or the effectivepermeability changes but not if both permeability and effective permeabilitychange by the same ratio. The tests described in this note were made todetermine the effect of overburden pressure on permeability and effective gaspermeability in the gas-oil system. The gas-oil system was chosen because theavailable equipment was best suited for studying this system. The resultantdata can be applied to other systems of interest because the gas permeabilityin the gas-oil system is the permeability of the nonwetting phase and, as such, is equivalent to the gas permeability in the gas-oil-water system and to theoil permeability in the oil-water system.
Cylindrical test plugs, one in. in diameter and one in. long, were cut fromsandstone core samples from three different reservoirs. After extraction intoluene, the plugs were mounted in Lucite by conventional core mountingmethods. The core properties are given in the legend in Fig. 1. The mountedcores were machined to fit the apparatus shown in Fig 4. Air permeabilities asa function of overburden pressure were measured by connecting lines (1) and (2)to a conventional air permeameter.
T.N. 194
The Steady-State Flow of Gas Through Glass Capillary Tubes
Authors: Wallick George C. 
Published: April 2012

Abstract
This paper describes experimental procedures for the calibration ofcapillary tubes to be employed as comparison standards in gas flow-ratemeasurements and considers several types of flow which were observed in thecalibration of seven capillaries of varying diameter. It is shown that undercertain experimental conditions deviations from Poiseuille flow are observedwhich may not be attributed to turbulence, and that this flow behavior may bedescribed empirically by introducing the classical kinetic energy correctioninto the Poiseuille equation.

Introduction
Techniques have been developed for the measurement of the volume rate offlow of nitrogen through glass capillary tubes as a function both of thedifferential pressure applied and of the absolute gas pressure. Capillary tubesthus calibrated are frequently used to determine the rate of gas flow through aporous sample in the measurement of slip-corrected permeability. The purpose ofthis note is to describe the calibration procedure and to discuss some observeddeviations from the ideal flow behavior predicted by the Poiseuilleequation.

Experimental Procedure
The volume flow rate of nitrogen as a function of the differential pressurewas determined experimentally for a series of seven glass capillary tubes ofvarying diameter. As is shown in Table 1, the capillary radii in the seriesranged from 0.004 cm for Kl to 0.07 cm for K7. The capillary tubes were cutfrom capillary tubing purchased on special order from several manufacturers andthe bore radii were determined by microscopic measurement. The gas volume flowrate was measured for each capillary tube at a series of differential pressuresin the range from 0 to 3 cm of mercury and at average absolute pressures of1.0, 2.5, 4.0, and 6.0 atm.

Experimental Procedure for Small Capillaries
A schematic diagram of the apparatus used to calibrate the three smallestcapillaries, Kl, K2, and K3, is shown in Fig. 1. By means of a standard RuskaInstrument Corp. volumetric pump (equipped with a synchronous motor drive, twostages of gear reduction, and a quick-change lathe gear box), nitrogen wasdisplaced by mercury from a metal cell immersed in a constant-temperature bath.The pump, the line to the cell, and a part of the cell were filled withmercury. As mercury was forced into the cell, it displaced nitrogen whichpassed through the capillary tube being calibrated and into a large containerwith a volume of approximately 30 liters.
T.N. 206
Computation of a Linear Flood by the Stabilized Zone Method
Authors: Jones-Parra J. , Calhoun John C. 
Published: April 2012

Introduction
The purpose of this paper is to present the results obtained by solving thefractional flow and frontal advance equations to obtain oil recovery at waterbreakthrough as a function of the length of the system being flooded, thelinear velocity of injection and the displacing phase viscosity. The method ofsolution makes use of the stabilized zone concept first presented byTerwilliger, et al. when calculating saturation distributions in a gravitydrainage system. In order to check the calculated results, the equations andmethod of solution were applied to the system on which Rapoport and Leasreported experimental data.

Method of Solution
The solution of the fractional flow equation
(Equation 1)
and the frontal advance equation
(Equation 2)
is obtained by assuming that a water front forms to sweep the oil out ahead ofit. There is ample evidence that under the proper conditions a water front doesform. If this water front is not to dissipate, the water saturations whichcomprise it must have equal linear velocities. These water saturations are saidto comprise the stabilized zone. Equation (2) indicates that for all thesesaturations
(Equation 3)
and hence fw must plot as a straight line against saturation for those watersaturations comprising the stabilized zone.
The water saturations lying between the highest in the stabilized zone andthe highest that can be achieved in the porous medium comprise the variablezone.
T.N. 193
Do IRS Audits Deter Corporate Tax Avoidance?
Authors: Hoopes Jeffrey L. , Mescall Devan , Pittman Jeffrey A. 
Published: April 2012

ABSTRACT
We extend research on the determinants of corporate tax avoidance to include the role of Internal Revenue Service (IRS) monitoring. Our evidence from large samples implies that U.S. public firms undertake less aggressive tax positions when tax enforcement is stricter. Reflecting its first-order economic impact on firms, our coefficient estimates imply that raising the probability of an IRS audit from 19 percent (the 25th percentile in our data) to 37 percent (the 75th percentile) increases their cash effective tax rates, on average, by nearly two percentage points, which amounts to a 7 percent increase in cash effective tax rates. These results are robust to controlling for firm size and time, which determine our primary proxy for IRS enforcement, in different ways; specifying several alternative dependent and test variables; and confronting potential endogeneity with instrumental variables and panel data estimations, among other techniques.
JEL Classifications: M40; G34; G32; H25.
Anderson-Hynes Pyeloplasty in Children: Nonintubated Versus Intubated
Authors: Hasan Gazi Zahirul , Hossain AKM Zahid , Amin Md Ruhul , Hoque Shafiqul , Siddiqui MTH 
Published: April 2012

Objective: To compare between nonintubated versus intubated Anderson-Hynes (AH) pyeloplasty in children.Study Design: Prospective studyStudy place: Department of Paediatric Surgery, Bangabandhu Sheikh Mujib Medical University (BSMMU), Dhaka, Bangladesh and some private clinics of Dhaka city. Study period: March 2001 to December 2008.Subjects: A total of 75 patients were included in this study. They were divided in two groups. Nonintubated Anderson-Hynes pyeloplasty was done in 45 patients and intubated Anderson-Hynes pyeloplasty was done in 30 patients.Results: The anastomotic leakage of urine, urinary tract infection, hospital stay and improvement of differential renal function were assessed post operatively in both nonintubated and intubated groups. This study showed that there was no anastomotic failure and no post operative urinary tract infection in either group. The percentage of improvement of differential renal function is almost same in both the groups. The post operative hospital stay was markedly reduced in nonintubated Anderson-Hynes pyeloplasty. In this study the post operative hospital stay in nonintubated group was average 6 days and it was average 16.5 days in intubated group.Conclusion: From this study it may be concluded that the effects of nonintubated AH pyeloplasty is as good as intubated one but an additional advantage of significantly less post operative hospital stay was observed in nonintubated group.DOI: http://dx.doi.org/10.3329/bjch.v35i2.10378 Bangladesh J Child Health 2011; Vol 35 (2): 59-61