bluuebunny/crossref_metadata_2025_split huggingface dataset:
A High Temperature Gauge Glass for the Visual Observation of Critical Phenomena
Authors: Spencer John R. 
Published: April 2012

Abstract
A capillary tube variable volume cell is described, which has operatedsatisfactorily over a range of 100'F and 3,500 psi to 550'F and 1,500 psi. Thecell contents are entirely visible over the length of the capillary with theexception of a space at the top amounting to three per cent of the totalvolume. Observations on the critical behavior of simple systems have beengreatly facilitated by the apparatus, it being possible to establish thecritical conditions for a particular mixture in the course of a day'srun.

Introduction
Many types of apparatus have been designed for obtaining data on the phaserelationships of hydrocarbon systems. Such apparatus can in general besubdivided into two classifications;indirect measurement of phase volume, anddirect visual observation of phase volume, each of which hasoutstanding advantages and disadvantages.
Indirect measurement of phase volume requires the use of rather elaborateapparatus including internal probes in which are located the device fordetermining the locus of the interface between phases. Such equipment is by itsvery nature costly, and is complex from the standpoint of operating technique.Probing techniques can be used, however, over wide ranges of temperature andpressure with a high degree of reproducibility.
Apparatus for visual observation of phase behavior obviously has theadvantage of enabling the experimenter to see exactly what takes place, butbecause the material to be tested is contained in a cell constructed of bothmetal and glass, is limited severely as to the temperature range of operation.Furthermore, the maximum pressure usually is limited by the choice of materialused for sealing the glass to the metal, and by the strength of the glassitself. In the interest of increased efficiency of observation, as much of thecell as possible should be visible to the eye. Glass capillary tubes have beenused successfully but have always given difficulty at the metal-to-glass seal.An apparatus has been devised to overcome the problems of sealing andresistance to temperature effects that have heretofore been the limiting factorwith glass apparatus in the observation of phase volumes at elevatedtemperature and pressure.
T.N. 85
Efficiency of Gas Displacement From Porous Media by Liquid Flooding
Authors: Geffen T.M. , Parrish D.R. , Haynes G.W. , Morse R.A. 
Published: April 2012

Abstract
Flow tests on small core plugs have indicated that a large amount of gas istrapped and not recovered by water flooding a gas sand. Instead of 1 to 15 percent pore space, as is usually assumed, the residual gas saturation is 15 to 50per cent pore space, and is thus of the same magnitude as residual oil afterwater flooding oil sands.
A thorough investigation was made to ascertain that large amounts ofresidual gas actually remain in reservoirs after a water flood and that thiscondition is not merely a laboratory phenomenon. In field experiments, theamount of gas left in a watered-out gas sand was measured by use of a pressurecore barrel and the residual gas saturation of two watered-out gas sands wasdetermined by electric log evaluation. In the laboratory, an investigation wasmade of factors that could possibly cause the value of residual gas saturationas measured on small core plugs to differ from that in the reservoir, and theeffect of these factors on the amount of residual gas saturation was studied.The factors studied include flooding rate, static pressure; temperature, samplesize and saturation conditions before flooding. All evidence established that arelatively high gas saturation is trapped in water flooded gas sands and thatthis residual gas saturation can be measured in the laboratory by tests onsmall core plugs.

Introduction
There has been general agreement among engineers that very high recovery ofgas could be obtained from natural reservoirs by water displacement. Gasrecoveries of 80 to 95 per cent of the original gas in place have become thenormal expectation in water drive fields. The assumption of high recovery hasbeen based on:low density and viscosity of gas compared with water;the erroneous assumption that the flow relationships in a gas-liquid systemwhere gas is the displaced phase will be the same as when it is the displacingphase.
It has long been recognized that gas can flow at very low gas saturations(in the range of 1 to 15 per cent pore space) in systems where liquid is beingdisplaced by gas. By assuming the reversibility of this process, the conclusionwas reached that the residual gas saturation following water flooding of a gasreservoir would be the same (l to 15 per cent) as that at which gas firstflowed continuously as a displacing phase.
T.P. 3279
Improved Multiphase Flow Studies Employing Radioactive Tracers
Authors: Josendal V.A. , Sandiford B.B. , Wilson J.W. 
Published: April 2012

Abstract
Two radioactive tracers have been tested as a means of determining coresaturation in multiphase flow studies. Cesium 134 chloride was tried as awater-phase tracer, but complications in its use in low permeability coresresulted from sorption of cesium by the core or water-wet pads. Iodo 131 benzene proved very satisfactory as an oil-phase tracer. The synthesis ofiodobenzene from the sodium iodide as received from Oak Ridge is simple anddirect. The tracer is insoluble in water and there was no evidence of sorptionby any of the core materials used.
Use of the method to determine saturation profiles during capillary anddynamic desaturations and relative permeability measurements on oil-water andoil-gas systems is described. Comparisons of the dynamic and capillary methodsof relative permeability determination were made using the tracer to check coresaturation and saturation distribution. Other experiments are also described inwhich mobility of the oil phase at various saturations was measured bydisplacing labeled oil by flowing inactive oil. Similar experiments were madeusing water labeled with cesium 134.

Introduction
To be fundamentally sound, any laboratory method of determining relativepermeability must meet, among others, the following requirements:the coresaturation between the pressure taps must be uniform, andthere must beuniform pressure difference between the phases in the region between thepressure taps.
In practice it may eventually be shown that appreciabledeparture from either or both of these conditions may be permitted withoutintroducing sensible error, but the magnitude of such error remains to beestablished. There is need then for methods of saturation determination whichwill determine the saturation profile in a core as well as the overall averagesaturation given by the gravimetric or material balance methods usuallyemployed.
Methods which have received consideration include resistivity, X-rayabsorption, gamma ray absorption, neutron diffraction, and radioactive tracers.The resistivity method has use in the determination of profile, but needschecking by independent means. The X-ray method has been used successfully, butrequires elaborate equipment and calibration. At present gamma ray absorptionis practical only for very large cores. The neutron method does not appearadaptable to measurement of saturation variations in short cores since it is ascattering method. Russell, Morgan and Muskat employed radiovanadium in a studyof the mobility of interstitial water. Coomber and Tiratsoo used radioiodine asan oil-phase tracer and measured profiles in unconsolidated sand packs.
T.P. 3284
The Resistivity of a Fluid-Filled Porous Body
Authors: Owen J.E. 
Published: April 2012

Abstract
A model of a porous body is presented in which the pore space consists of asystem of voids and interconnecting tubes. Relationships between porosity andresistivity formation factor are determined partly by calculation, partly byexperiment. Constriction effects characteristic of the model are shown to besufficient to account for high formation factors. It is shown that constrictionmay be combined with moderate amounts of tortuosity to give model pore systemsexhibiting to a first approximation porosity and resistivity properties similarto those of natural porous bodies.

Introduction
The relationship between the electric resistivity of a fluid-filled porousbody and the geometry of its pore space is so complex that the calculation ofthe resistivity of a natural porous rock is a practical impossibility. Both theresistivity of a body and its porosity are measurable quantities, however, andprevious successes at relating them have been reached by an empirical approach.Efforts at obtaining theoretically derived formulae relating them havegenerally been unsatisfactory. One of the reasons for this may lie in the puregeometry that has been assumed.

The Tortuosity Concept
A parameter called the formation factor is useful in discussing theresistivity of a fluid-filled porous body. This parameter is the ratio of theresistivity of a fluid saturated porous body to the resistivity of thesaturating fluid. Formation factors are often available from measurements oncores or from electric logs, and many attempts have been made to correlateformation factors and porosities of geological formations. Whenever asuccessful correlation is found, the engineer working with electrical logs hasa useful tool for the determination of porosities of pay sections.
T.P. 3352
The Strataflow Process: A Recent Development in Locating Water Entry in Wells
Authors: Hartline Ralph E. , Tapper Wilfred 
Published: April 2012

Abstract
The Strataflow process for locating water entry in producing wells is nowavailable. This method as now practiced utilizes the fact that fluids ofdifferent salinities have different electrical resistivities. By introducinginto the well a fluid of a markedly different salinity than that of the fluidbeing produced, a pronounced resistivity change will occur at the point ofentry. By running a Strataflow survey the points of major and minor water entrymay be interpreted from changes in the resistivity of fluid in the hole.
Strataflow results are obtained with the well operating under almost normalproducing conditions, and are a logical primary step in any workover program, having as its purpose shutting off of the water.

Introduction
Water production is a serious problem in many producing oil wells. Itcertainly increases lifting costs and in some cases presents a disposalproblem. It often aggravates corrosion problems and can even endanger oilproduction. With accurate information to guide an effective workover program, many marginal wells could be restored to profitable production.
The shortcomings of previous methods of water entry location wererecognized. The Strata flow process is the result of several years ofdevelopment and field testing directed toward overcoming these limitations. Itrepresents the continued development of a process reported by Silverman andBrown. The earlier work established the basic soundness of fresh-to-salt waterresistivity contrast in delineating zones of water entry, but its applicationwas limited by the difficulty of maintaining static balance of the well duringpreparation for the test. A more serious deterrent to its use, however, was itsunadaptability to existing well logging service equipment and field operatingmethods.

Strataflow Principle
The general principle of the new method involves, first, conditioning thewell by displacing the fluid in the bore of the well adjacent to the zone to betested by a conditioning fluid which is miscible with the formation fluid. Thisdisplacement is carried out without interruption of the well production. Theconditioning fluid must have some measurable physical, chemical, nuclear, orelectrical property which is distinctive from that of the formation fluid.
T.P. 3351
Some Properties of Mixed Paraffinic and Olefinic Hydrates
Authors: Reamer H.H. , Selleck F.T. , Sage B.H. 
Published: April 2012

Abstract
An experimental investigation was made of the effect of temperature upon thethree-phase pressure associated with the propane-water and propene-watersystems when hydrates were present. In addition, the characteristics of thepropane-propene-water system were established over a limited range oftemperatures under conditions such that hydrate was formed. The hydrate phasefor this system may be a solid solution and the distribution of propane andpropene in it is similar to that found in the coexisting hydrocarbon liquidphase.

Introduction
A knowledge of the characteristics of hydrates of the hydrocarbonsencountered in industrial practice is of importance in connection with thedesign of process equipment. Villard carried out early studies of hydrates, andde Forcrand considered the more probable compositions of the hydrates ofhydrocarbons. Hammerschmidt presented information about the propane-water andthe isobutane-water systems. Scheffer studied the hydrate of hydrogen sulfidein detail, and de Forcrand reported on the hydrates of krypton, argon, andxenon.
Roberts and co-workers determined the nature of the hydrates formed in themethane-water and ethane-water systems. Carson and Katz studied themethane-propane-water, methane-pentane-water, and the methane-hexane-watersystems in the four-phase region. The results of this rather extensiveinvestigation indicated that the paraffinic hydrates formed solid solutions.The experimental evidence now available does not support the existence ofhydrates of the pentanes-and heavier hydrocarbons but it cannot be stated withcertainty that such hydrates are not formed. Stackelberg made extensive studiesof the crystal structure of paraffinic hydrate, by means of x-ray techniquesand found that hydrates posses, a definite structure and composition. Theexistence of such a structure does not preclude the formation of solidsolutions of hydrates in aqueous systems containing two or morehydrocarbons.
Wilcox, Carson and Katz reviewed the information on the hydrates ofimportance in the processing of natural gas and presented data concerning theirformation from natural gas. Kobayashi and Katz made studies at high pressure ofthe hydrate of methane, and Unruh and Katz investigated hydrates in mixtures ofcarbon dioxide and methane.
Frost and Deaton contributed to the knowledge of the composition of theparaffinic hydrates. The irregularities in the experimental results wereseveral times the expected uncertainties. This experience confirms the behaviorencountered by other investigators indicating that hydrates tend to occludewater during their formation, thus rendering difficult the direct measurementof their composition.
T.P. 3376
Electrical Resistivity Measurements on Reservoir Rock Samples by the Two-Electrode and Four-Electrode Methods
Authors: Rust C.F. 
Published: April 2012

Abstract
Experimental evidence is presented showing that reproducible formationresistivity factor measurements and resistivity index determinations onreservoir core samples may be made utilizing either the two- or four-electrodemethods. Equipment is described which permits the application of eithertechnique to the core specimen without loss of time and with a minimum amountof effort. Since electrical resistivity measurements on reservoir rocks areimportant not only in electric log interpretations, but also in the study offundamental rock parameters, it was considered desirable to compare theapplicability of both techniques of resistivity measurement.

Introduction
The techniques employed in the measurement of electrical resistivity onreservoir rocks, as practiced in the petroleum industry, may be reduced to twofundamental methods: one utilizing two electrodes only, usually referred to asthe two-electrode method; the other using two additional electrodes andcommonly known as the four-electrode method. In the former, the core samplewhose resistivity is to be measured is mounted between two electrodes, usuallymetal discs, which serve to pass a current of known magnitude through thesample. The potential drop across the sample, measured between these same twoelectrodes, and the core dimensions furnish the necessary data to compute theresistivity of the sample. In the four-electrode technique the end plates, again usually of metal, still serve as current electrodes. Additional probes orelectrodes dispersed along the sample are utilized to measure the potentialdrop. Both methods are used in practice, and it is the purpose of this paper tocompare the two techniques as applied to the determination of formationresistivity factors and the resistivity index exponent n, in Archie's empiricalequation. To evaluate the two techniques it is desirable to point out theexperimental precautions which must be taken to insure reliable results. It isevident from the electrode arrangements of the two- and the four-electrodemethods that, for a given sample, the volume of sample included by thefour-electrode method is less than the volume included by the two-electrodemethod.
One of the prime difficulties associated with the two-electrode method isthe possible occurrence of an abnormally high resistance between the electrodesand the brine-saturated sample, which results in erroneous resistivity valuesfor the core sample itself.
T.P. 3397
Procedure for Use of Electronic Digital Computers in Calculating Flash Vaporization Hydrocarbon Equilibrium
Authors: Rachford H.H. , Rice J.D. 
Published: April 2012

Abstract
The effectiveness of digital computing machines in making technicalcalculations depends on how well the work is arranged to utilize the capabilityof the machines. This note presents a particularly useful way of calculatinghydrocarbon vapor-liquid equilibrium in the flash vaporization (orcondensation) system. The method is well suited to sequence-controlledcomputing equipment. It is not limited to equilibrium calculations and may beused for solution of most implicit equations in one variable.

Introduction
There is increasing interest in the use of electronic digital computers inresearch and engineering calculations. This is a fortunate and inevitable trendin view of both the increasingly extensive numerical work which is becoming aroutine part of many daily production operations and growing demand for theoverwhelming amounts of calculations required by newly developed numericalmethods for solving heretofore unsolved problems.
Machines are in many ways ideally suited to the task but of necessitypresent certain difficulties for a particular problem to be solved must oftenbe formulated quite differently from the way it would be arranged for manualsolution. This is done in order to take advantage of the inherent speed andprecision of electronic computers and at the same time to limit the need fornumber storage to the capacity of the machine. Therefore, this note issubmitted to present a general and quite powerful method of finding solutionsof the frequently encountered implicit equation:
(Equation 1)
where the root, x0, is to be found for a given set of y1… yn. Theprocedure is well suited for use with computing machines, for it usuallyrequires but little storage or programming beyond that necessary to evaluateF.

Hydrocarbon Equilibrium
The method is described in terms of the problem it was designed to solve, i.e., the calculation of hydrocarbon vapor-liquid equilibrium in flashvaporization. Given the composition of a hydrocarbon mixture and appropriatevalues of the equilibrium ratios K, to find the phase ratio and compositions ina closed system: let zi be the mol fraction of the i-th component in themixture.
T.N. 136
Reduction in Permeability With Overburden Pressure
Authors: Fatt I. , Davis D.H. 
Published: April 2012

Oil bearing rocks, usually found at depths of 2,000 to 10,000'Ft, areelastically deformed by overburden pressure. Although the change in porositywith pressure in a number of example rocks has been shown to be small, it wasthought that overburden pressure might have a significant effect onpermeability. This note presents results of an investigation to determine themagnitude of the change in permeability with pressure.
In routine core analysis, permeabilities are measured on rock samples whichare not under overburden pressure. If permeability measured in this way differsfrom permeabilities measured under overburden pressure, a systematic error isintroduced into well productivity calculations. The experiments described inthis report were made to determine the magnitude of the change and thus to givean estimate of the error introduced into the calculations. The error introducedby the neglect of the change in permeability when overburden pressure isremoved may account for part of the difference between well productivitycalculated from core analysis and the actual well productivity.
The results obtained in this investigation have only qualitativesignificance because of the difficulty in reproducing in the laboratory thestress conditions on the rock buried in the earth. The assumption which isusually made is that the rocks in the earth are under a uniform pressure equalto the weight per unit area of the vertical overburden column from the rock inquestion to the surface of the earth less the pressure of the liquid in thepores of the rock. For an overburden consisting of sandstones and shales (ofassumed average specific gravity of 2.3) and for a liquid pressure equal to thepressure in a salt water column (of specific gravity 1.0) reaching from therock to the surface, the resulting net pressure on the rock is approximately0.56 psi per ft of depth.

Experimental Method
Clean, dry sandstone core plugs one in. in diameter and about three in. longwere mounted in a copper foil jacket as shown in Fig. 3 or molded in a Lucitejacket as shown in Fig. 4. All cores except those labeled "2" in Fig. 1and "8" in Fig. 2 were measured in the copper foil jacket. Cores"2" and "8" were measured' in the Lucite jacket.
T.N. 147
Reservoir Performance and Well Spacing, Spraberry Trend Area Field of West Texas
Authors: Elkins Lincoln F. 
Published: April 2012

Summary
The Spraberry Trend Field of West Texas was discovered in January, 1949.Drilling of 2,234 wells and production of some 45 million bbl of oil byJanuary, 1953, indicated this to be an important field which will ultimatelycover more than 400,000 acres. In addition to being the world's largest fieldin areal extent, the Spraberry has presented many problems in well completionand operation and has demonstrated unique reservoir performancecharacteristics.
The pay section consists primarily of a few fine grained sandstone orsiltstone members in a thousand-ft thick section of shale, limestone, andsiltstone. Since porosity averages only 10 per cent and nearly allpermeabilities are less than 1 md, conventional core analysis does notdelineate the "pay" section. Mercury injection was used as a capillarypressure test adaptable to rapid routine use to select those intervals havinglow enough connate water saturation to contain commercially significant oilsaturation. In the central area of the field this "pay" amounts to 16ft of Upper Spraberry and 15 ft of Lower Spraberry sands.
An interconnected system of vertical fractures, observed in cores, providesthe flow channels for oil to drain into the wells but most of the oil is storedin the matrix since the void volume of fractures is estimated to be less than 1per cent of that in the sand. Initial potentials of wells range up to 1,000 BIDafter fracture treatment which should be compared with estimated capacity of 5to 10 BID if oil had to flow into the wells through the sand itself.
Without exception initial pressures of later drilled wells weresignificantly lower than initial pressures of earlier drilled nearby wells in alarge area some 6 miles long. This means the earlier drilled wells had drainedfluids from areas much greater than their 40-acre proration units.
T.P. 3622