bluuebunny/crossref_metadata_2025_split huggingface dataset:
Pressure Distribution in Unsaturated Oil Reservoirs
Authors: Brownscombe E.R. , Collins Francis 
Published: April 2012

The pressure distribution in a reservoir producing an incompressible fluidby radial flow in a horizontal structure is a simple logarithmic function useddaily by reservoir engineers. The assumption of an incompressible liquid isequivalent to assuming that pressure is maintained constant at the well radiusand at some external ?radius of drainage,? or, in other words, that the entireflow into the well passes across the external radius. In most cases a well issurrounded by other wells draining adjoining areas so that the ?radius ofdrainage? is not a line of constant pressure with flow equal to the flow intothe well but rather a contour of zero pressure gradient across which no flowoccurs, production being due to the expansion of the liquid within thearea.
The radial flow steady state pressure distribution for this case does not seemto be extensively used despite the fact that the mathematical analysis has beengiven in detail and the results are simple and generally applicable. The objectof this discussion is to develop this result from a physical rather than amathematical viewpoint, thereby aiding intuition in judging circumstances towhich it may be applicable.
If the production rate at a well in an unsaturated reservoir is maintainedconstant while no flow occurs across the outer radius a steady state will soonbe reached in which the flow rate or pressure gradient is constant with time atall points in the reservoir. To preserve such a condition it is necessary thatthe pressure decline at the same rate at all points in the reservoir, that is, the curves of pressure versus radial distance at successive times are allparallel. Then each unit volume of oil is expanding at the same rate andcontributing an equal share to the production.
T.N. 61
High-Pressure Mercury Pump
Authors: Spencer J.R. 
Published: April 2012

When supplies of high pressure mercury or other liquids are required inanalytical work, it is convenient to have the source of supply at a relativelyconstant pressure and available in sufficient volume to satisfy therequirements of the apparatus in use. It is also desirable that the pressuringdevice be as simple and as inexpensive as possible and convenient to operate.This pump combined with a small storage reservoir containing gas under pressurehas the attributes ofpositive control of the maximum output pressurethrough the use of a regulator in the low pressure air supply;anincreasing capacity as the rate of withdrawal of mercury from the pressuredsystem is increased; andsimplicity, requiring only the use of a lathe, drill press, and welding unit in its construction.

Description
Essential parts of the pump are shown in Fig. 1. In appearance the unit issimilar to the usual steam pump in common use in industrial applicationsalthough considerably smaller in size. The main differences lie in the arearatio of the air and mercury pistons and in the design of the air valvemechanism. Approximate diameters of these pistons are 4.25 in. to 0.375 in.respectively, giving an area ratio of about 130 to 1. The air piston (2) isattached to the end of shaft (4), with the mercury piston being merely areduced extension of the shaft. Mercury intake and discharge to the pump arecontrolled by high pressure check valves that screw into the ports indicated at (6). Air supply is controlled by the valve assembly mounted on top of the maincylinder (1).
T.N. 62
Some Controlling Factors Regarding Variable Weighting of Cement Slurries
Authors: Mallinger M.A. 
Published: April 2012

Abstract
A series of laboratory tests was conducted to determine the limits ofpracticability in regulating the weights of various cement slurries. It wasfound that slurry weights of 12 to 19 lb per gallon could be obtained by addingbentonite to decrease the weight and barytes ore to increase the weight. It wasalso found that barytes ore was not usable in all cements.

Lightweight Cement Slurries Introduction
During the drilling and completion of oil wells the magnitude of the hydraulicpressures exerted on certain formations is critical. In many cases considerablecare must be exercised to prevent drilling mud weights from becoming too high, and in those wells where loss of circulation is a problem, the use of normalweight cement slurries will generally result in lost returns during casingcementing operations. While mud weights can easily be controlled, it isnecessary to exercise care in the selection of weight reducing additives forcement slurries in order that slurry weights may be reduced sufficiently toprevent the loss of a large portion of the cement to the thief formationswithout seriously affecting the setting properties of the cement.

Experimental Results
An extensive search revealed that a large number of materials that might havebeen otherwise practicable as a weight reducing additive were not acceptablefor use with oil wet cements because the imposition of pressure on the slurriescaused the additive being tested to be compressed or to absorb water from theslurries, resulting in negligible decrease in the slurry weight.
This search for lightweight additives disclosed that bentonite, a material verycommonly used for reducing the weight of drilling muds and cement, produced thebest results without undue harmful effects on the properties of oil wellcements.
T.N. 64
An Investigation of the Electrokinetic Component of the Self Potential Curve
Authors: Wyllie M.R.J. 
Published: April 2012

Abstract
Eight laboratory-prepared aqueous base drilling muds representing common mudtypes, and 15 aqueous base drilling muds sampled in the field, have been usedin an experimental investigation of the relationship between the streamingpotential developed across a mud filter cake and the differential pressurecausing filtrate flow.
It has been established that the relationship is of the form, Es = kPy, where Es is the streaming potential, P the differential pressure and k and yare constants for any particular mud system at constant temperature. Beyond acertain minimum thickness this relationship is independent of filter cakethickness. Experiment has shown that both k and y are temperature dependentparameters and that in certain mud systems there is a critical value of P abovewhich the simple relationship Es = kPy ceases to hold. The constant k tends tobe a function of the mud resistivity at 77'F, but the exponent y has not beenfound to be related to any commonly measured mud property.
Certain field experiments are described which serve to demonstrate that thetotal SP (self potential) developed opposite a formation may be quantitativelyaccounted for as the algebraic sum of an electrochemical potential and anelectrokinetic potential. A chart to permit the simple use of mean solutionactivities in the interpretation of electrochemical SP data is given and itsuse described.
Various field methods for computing the electrokinetic SP component of thetotal SP are considered and rejected as being unduly complicated andinaccurate. It is shown that the employment of low resistivity drilling muds isessential if optimum accuracy is desired in the use of the S.P. curve for thepurpose of computing connate water salinities by the electrochemical SP method.The use of such low resistivity drilling muds is accordingly recommended.
T.P. 2940
Special Considerations in Predicting Reservoir Performance of Highly Volatile Type Oil Reservoirs
Authors: Cook Alton B. , Spencer G.B. , Bobrowski F.P. 
Published: April 2012

Introduction
In estimating production gas/oil ratios and oil recoveries from reservoirscontaining highly volatile oils it is highly important to include condensatethat may be recovered from the gas produced from the reservoir. The volume ofthe hydrocarbon liquid condensed from the production of the solution gas thathas been liberated in some reservoirs may equal or even exceed the volume ofrecoverable stock-tank oil as estimated by present methods. The usual procedurein estimating future reservoir performance includes use of relativepermeability data of the reservoir rock to gas and oil and includesmaterial-balance calculations utilizing data on the volume of the reservoirfluids, oil and gas production and reservoir pressure decline, and data on thephysical properties of the initial reservoir fluids. The inaccuracy in theprocedure results from the false assumption that all of the free or liberatedgas that enters the well bore of reservoirs containing highly volatile oilsremains in the gaseous phase as it is produced.
This paper presents a method for estimating future reservoir performance andoil recoveries based on special laboratory analyses of reservoir-oil samplesand recognition of the additional volume of hydrocarbon liquid that will berecovered at various stages of depletion from a solution-gas-drive reservoir.The method also includes calculations of the volume and composition of thehydrocarbon liquids that can be recovered by processing the produced gas in anatural-gasoline plant. The development of the method resulted from a study oflaboratory analyses of reservoir samples and of field data obtained from tworeservoirs containing oil of the highly volatile type.
Relatively high pressures and temperatures prevail in oil reservoirsdiscovered at the greater depths of present-day drilling. The contained fluidsmay have high saturation pressures and large volumes of gas in solution. Theoils and gases under these conditions may be almost identical in compositionsand densities. Also, engineers have noted that, for a number of oil reservoirsand especially the deeper reservoirs, the API gravity of the stock-tank oilincreases as the production gas/oil ratios increase. They attributed thisincrease in API gravity of the stock-tank oil to the formation of condensate asthe liberated gas in the reservoir is being produced.
T.P. 3017
Interfacial Tensions at Reservoir Pressures and Temperatures; Apparatus and the Water-Methane System
Authors: Hough E.W. , Rzasa M.J. , Wood B.B. 
Published: April 2012

Abstract
An apparatus for the determination of fluid-fluid interfacial tension by thependant drop method has been constructed. The apparatus is refined beyond thosepreviously described in that the samples are introduced into an evacuatedwindowed cell without contacting air or mercury.
Interfacial tension data are reported for the water-methane system between 74and 280'F and 15 and 15,000 psi.
The variation of wettability of the stainless-steel dropper tip withpressure and temperature was observed incidentally to the measurements.

Introduction
The most refined previous apparatus for the determination of fluid-fluidinterfacial tension at reservoir conditions was built by Hauser and Michaels.These authors used the pendant drop method, previously investigated by Andreas, Hauser, and Tucker. Recently, Fordham has made the pendant drop method anabsolute one by numerical integration of the differential equation of dropshape. It is necessary to know the difference in density of the two fluids andthe acceleration due to gravity in order to evaluate the interfacial tensionfrom measurements of drop dimensions. Contact angle is not involved in themeasurements by this method.
Some precise tests of the method have been made at atmospheric pressure and77?F by Douglas, who found agreement with established values to within about0.1 per cent for water and air, cyclohexane and air, benzene and air, andbenzene and water. No values of interfacial tension from the recent pendantdrop apparatus have been published by Hauser and Michaels. However, values forthe water-benzene and water-decane systems are given in Michaels thesis forpressures from 15 to 10,000 psi and temperatures from 73 to 268?F. Somedeterminations on gas-oil and gas-water systems in the range of 15 to 4,000 psiand 78 to 178 of have been made by Hocott, by the drop-volume method. Thecapillary rise method has been used to investigate the interfacial tension ingas-oil systems at 88 of to several thousand psi by Swartz. Otherdeterminations in gas-oil systems at pressures under 1,000 psia have been madeby Jones, and Beecher and Parkhurst. The scarcity of data for pressures above5,000 psi is apparent.
T.P 3019
Variable Characteristics of the Oil in the Tensleep Sandstone Reservoir, Elk Basin Field, Wyoming and Montana
Authors: Espach Ralph H. , Fry Joseph 
Published: April 2012

Abstract
In the spring of 1943, when it was evident that the Tensleep sandstone inthe Elk Basin Field, Wyoming and Montana, held a large reserve of petroleum, Bureau of Mines engineers obtained samples of oil from the bottom of nine wellsand analyzed them for such physical characteristics as the volumes of gas insolution, saturation pressures or bubble points, shrinkage in volume caused bythe release of gas from solution, expansion of the oil with decrease inpressure, and other related properties. The composition of the gas in solutionin the oil was studied. The pressures and temperatures existing in thereservoir and the productivity characteristics of the oil wells weredetermined.
The data obtained indicate that the oil in the Tensleep Reservoir of the ElkBasin Field has unusually varying physical characteristics, such as asaturation pressure of 1,250 psia and 490 cu ft of gas in solution in a barrelof oil at the crest of the structure and a saturation pressure of 530 psia and134 cu ft of gas in solution in a barrel of oil low on the flanks. The hydrogensulfide content of the gas in solution in the oil varies from 18 per cent foroil on the crest to 5 per cent for oil low on the flanks of the structure. Ofeven greater significance is the fact that these and other variablecharacteristics of the reservoir oil are related to the position of the oil inthe structure. Many geologists and petroleum engineers have considered that allthe oil in a petroleum reservoir has rather uniform physical characteristicsand that equilibrium conditions prevailed in all underground accumulations ofoil and gas; that such is not always so is borne out by the results of thestudy by the writers.
T.P. 3018
Vaporization Characteristics of Carbon Dioxide in a Natural Gas-Crude Oil System
Authors: Poettman Fred H. 
Published: April 2012

Abstract
The vaporization characteristics of carbon dioxide in a League City naturalgas - Billings crude oil system were studied at three temperatures, 38?, 120?, and 202' F and for pressures ranging from 600 to 8,500 psi. Variation of carbondioxide concentration up to 12 mole per cent in the composite showed no effecton the equilibrium vaporization ratios (K values) of the hydrocarbonconstituents or on the K value of carbon dioxide itself. It was shown thatcarbon dioxide is more soluble in crudes than in distillates which is contraryto the behavior of methane.
A working chart of carbon dioxide K values is presented.

Introduction
The study of the equilibrium vaporization ratios of mixtures of paraffinhydrocarbons has been rather thorough. In the past few years considerableattention has been paid to the vaporization characteristics of the so-callednoncondensable gases such as nitrogen, carbon dioxide, and hydrogen sulfide inmixtures of hydrocarbons, since they usually occur to some extent in most crudeoils and natural gases. Knowledge of this behavior is useful to both theproduction and refining phases of the petroleum industry.
This paper reports the equilibrium vaporization ratios (K's) of carbondioxide in a mixture of League City natural gas and Billings crude oil, andcompares them to those obtained in a natural gas-distillate system. Theequilibrium vaporization ratios for the hydrocarbon components in this systemhad previously been studied by Roland. In addition to the determination of theK values for carbon dioxide, the K values for methane and ethane were alsodetermined in order to observe what effect, if any, the presence of carbondioxide had on these K values. The concentration of carbon dioxide was alsovaried in order to observe the effect of this variable on the carbon dioxide Kvalues.

Experimental Procedure
The apparatus used in this study consisted of a stainless steel equilibriumcell of about 2 liters capacity. The cell was mounted on trunions permittingrocking in a thermostatically controlled oil bath. Two high pressure valvesfitted with steel tubing were mounted on the top of the cell, one was used forsampling the equilibrium gas phase and the other for sampling the equilibriumliquid phase by means of an induction tube within the cell. Stainless steeltubing from the bottom of the cell led to a mercury reservoir and manifoldwhich was connected to a free-piston type pressure gauge manufactured by theAmerican Instrument Co. and to a volumetric pump. The temperature of the oilbath was measured by means of a calibrated mercury-in-glass thermometer.
T.P. 3058
Mineralogical Studies of California Oil-Bearing Formations I - Identification of Clays
Authors: Nahin P.G. , Merrill W.C. , Grenall A. , Crog R.S. 
Published: April 2012

Abstract
A progress report of an experimental investigation into the role of clay inreservoir performance is presented. The paper gives some of the reasons forconsidering clay as a significant component and outlines the objectives of abroad field of study which it is intended to pursue. Descriptions of theanalytical methods used are given; these include X-ray diffraction, electronmiscroscopy, thin section petrography, infrared spectroscopy, and cationexchange analysis. A suite of the more important clay minerals has beenassembled and characterized by these methods for use as standards in coreanalysis. From the data obtained it appears that although no one method ofanalysis is diagnostic for all of the clay minerals the infrared techniqueshows considerable promise in this direction. For the present, one or moresupplementary methods should be used to confirm the clay mineralidentifications.
The methods of analysis are applied to field cores taken from representativeand widely differing strata especially as regards their susceptibility todamage by fresh water. Wells completed in the Stevens and Gatchell Zones in SanJoaquin Valley are particularly clear-cut examples of this behavior withStevens Zone wells being more adversely affected by fresh water. Cores fromthese zones have been studied and are discussed. It appears that differences inthis behavior can be ascribed to differences in the nature of the containedclays. The value of the infrared spectra of the clay fractions in establishingthe identity of the predominant clay minerals is given particular emphasis.

Introduction
It is a challenge to the technical resources of the petroleum industry thatwhen the economic limit of production is reached, from 40 to 70 per cent of theoil in California reservoirs remains unproduced even by use of the bestpresently known methods of recovery. The magnitude of this abandoned volume ofoil can be appreciated when it is considered that to 1950 in excess of 8billion bb1 has been produced from California reservoirs with estimatedeconomically recoverable reserves in known fields and pools totaling nearly 4billion bbl. If for every barrel of oil produced there is at least anotherbarrel still in place, it is evident that the revenue obtained from therecovery of only a few per cent of this volume would repay the cost of therequired research manyfold.
T.P. 3059
A Modified Low-Strength Cement
Authors: Morgan B.E. , Dumbauld G.K. 
Published: April 2012

Abstract
The need for a low-strength cementing composition for use in well cementingis reviewed and results are presented of laboratory and experimental fieldtests of a modified cement having a controlled ultimate tensile strength ofapproximately 200 psi. The modified cementing composition may be prepared fromeither high early strength or normal portland cements by the addition ofbentonite clay and a suitable agent for dispersing and controlling the set ofthe slurry. Substitution of the modified cement for conventional slow-setcements may give better completion results in many wells because the modifiedcementing composition has lower set strength, lower slurry density, and greaterslurry stability than conventional cement slurries. The lower ultimate strengthallows greater penetration with less shattering of the set cement whenperforating casing and cement. The lower slurry density allows the placement oflonger columns of cement slurry, and the greater slurry stability reduces thepossibility of having an uncemented section caused by the settling of cementparticles before the cement sets.

Introduction
High strength has always been one of the accepted criteria of a good cement.During the early use of portland cement in well cementing, emphasis was placedupon securing cements with higher strengths. In 1931, Barkis reported that,?Normal oil well cements have been improved to develop greater strengths anduniformity of product, which has aided in producing successful jobs incementing the deeper strings.?
As long as most wells were completed by the open-hole method, the use ofcements having high strengths seemed desirable, and there was no objectionraised against high-strength cementing compositions. For a number of years, however, the industry has been completing a large number of wells by settingand cementing casing through productive horizons and then obtaining productionby gun-perforating the section of casing opposite the desired interval.Although this method has been generally successful, difficulties have beenexperienced in some cases in completing or recompleting wells because ofapparent lack of adequate penetration by the bullets through the casing andsurrounding sheath of cement and into producing formation. In addition to thepenetration trouble, there have been indications that fracturing and shatteringof the set cement by perforating might be a contributing factor in causing thefailure of some jobs to exclude water or gas from oil producing zones.
T.P. 3062
A Gravel Pack Completion for Exclusion of Gas and Water
Authors: West Thomas S. 
Published: April 2012

Abstract
A gravel pack completion is described which, in addition to sand screening, permits the exclusion of water and gas from the oil production.
A gravel pack composed of alternate layers of different particle sizes isemployed which has horizontal but not overall vertical permeability to drillingmud. A packer is run on the tubing and set in the screen member, around whichthe gravel layers are placed. The hydrostatic pressure of a mud column preventsthe entry of fluid above (or below) the level of the packer. The producinglevel may be changed by raising or lowering the tubing.
Vertical coning is controlled by replacing the mud column with oil andcontinually injecting oil into the sand section above (or below) thepacker.
Three well histories with this completion are described in detail.Statistics on the first 100 completions of this general type are given.

Introduction
Gravel pack type completions have heretofore been almost exclusively for thepurpose of preventing sand production. This paper describes and presents welldata on a gravel pack procedure which is primarily a selective completionmethod. Although complete sand screening is achieved, the exclusion of gas andwater is the primary objective. The application of this procedure is thereforenot limited to unconsolidated sands. Application to hard sand or limestonereservoirs is equally feasible.

Gravel Pack Procedure
Figs. 1 and 2 illustrate the gravel pack procedure employed. The gravel isplaced by means of the frangible disc type dump bailer shown by Fig. 1. Thisbailer has its lower end closed by a plate glass or steel rimmed cement disc.This disc breaks when the bailer passes over the liner allowing the gravel tobe deposited around the liner. The liner employed is usually 2 3/8 in. to 2 7/8in. OD and 1.995 in. or 2.07 in. ID (ID of 2-in. tubing or 2-in. line pipe).Two types of slotted sections have been employed. One type employs horizontalhacksaw cut or milled slots of about 1/32 in. width opposite the producingsection. The other type employs the same type of horizontal slot, but slots areplaced in groups of six at intervals of about 8 in.
T.P. 3060