bluuebunny/crossref_metadata_2025_split huggingface dataset:
Some Theoretical Considerations Related To The Quantitative Evaluation Of The Physical Characteristics Of Reservoir Rock From Electrical Log Data
Authors: Wyllie M.R.J. , Rose Walter D. 
Published: April 2012

Introduction
The use of electrical well logs for the quantitative determination of suchreservoir parameters as connate water saturation, formation permeability andconnate water salinity has recently been attracting the attention of a numberof workers.
While the theory of the determination of connate water salinity from theself potential S.P. log has received rather detailed treatment, relativelylittle attention has been paid to the theoretical aspects involved in thequantitative interpretation of resistivity data. It is clear that if electricalwell logs can be used for the quantitative evaluation of physicalcharacteristics of reservoir rock, they will provide a valuable tool tosupplement cheaply information obtained by more laborious core analysis. Incertain cases it is conceivable that the coring program could be considerablycurtailed if the electric log could be relied upon to give reasonably accuratequantitative information.
It is our object in this paper to examine the theoretical basis ofquantitative log interpretation as expressed in such well-established loggingconcepts as formation factor and cementation factor. It is also our object toinvestigate the physical aspects of the relationship which is presumed to existbetween resistivity index and brine saturation in reservoir rock. Inparticular, we will endeavor to draw attention to the fact that it is possibleto express these logging concepts in terms of capillary pressure-saturationrelationships, permeability and tortuosity parameters which we will consider inthis paper to be fundamentally indicative of rock texture. The probability ofbeing able to obtain from log recordings alone the data theoretically essentialto permit quantitative log interpretation will be examined, and considerationwill also be given to the problem of formulating simple semiempiricalrelationships for use in the field.

Theoretical Considerations
The concept of formation resistivity factor, or as it is now commonlycalled, formation factor, appears to have been introduced by G. E. Archie.Formation resistivity factor as defined by Archie is the resistivity of a rock100 per cent brine-saturated divided by the resistivity of the brine. Thisrelationship had previously been used by physical chemists and the concept is, for example, implicit in an early treatment by Fricke of the conductivity of aqueous slurries.
T.P. 2852
The Coexistence of Liquid and Vapor Phases at Pressures Above 10,000 Psi
Authors: Rzasa Michael J. , Katz Donald L. 
Published: April 2012

Abstract
With greater effort being devoted to the discovery of new oil and gasreserves and a consequent increase in bottom hole pressures due to greaterdrilling depths, the phase relationships of hydrocarbon fluids at pressuresabove 10,000 lb psi are becoming increasingly important.
The present paper discusses the results of research with a windowed cell ona methane-Kensol 16 system to pressures of 25,000 lb psi and temperatures to260'F. Kensol 16 is a commercial high narrow-boiling-range oil.
It is shown that for the temperature range of 60'F to 260'F, this particularsystem exists in two phases to pressures of approximately 14,000 Ib psi, anddata are presented giving the relative amounts of liquid and vapor phasescoexisting under these conditions. Partial phase diagrams are shown for sixdifferent mixtures of methane and Kensol 16, three of which include thecritical region.
In contrast to mixtures composed of substances of fairly close volatility, critical opalescence was noted for as much as ?200'F of the criticaltemperature.
The critical locus of the methane-Kensol 16 system was estimated and theconventional pressure-composition and temperature-composition diagrams were prepared. From these, the equilibriumvaporization factors for methane and Kensol 16 were estimated for temperaturesfrom 60'F to 700'F and to pressures above 12,000 Ib psi.
The relations of this study to petroleum production problems and other phaseequilibria research are discussed.

Introduction
A knowledge of the physical behavior of naturally-occurring hydrocarbonmixtures is fundamental to a thorough treatment of nearly all operationsinvolved in the recovery, refining, and transportation of petroleum.
T.P. 2809
Relative Productivity of Perforated Casing-1
Authors: Howard Robert A. , Watson Marsh S. 
Published: April 2012

Abstract
An electrolytic model study has been made of the relative productivity ofperforated casing. The results show that the relative productivity is roughlyone-half to two-thirds of that predicted from point-sink calculations. Thisdiscrepancy can be satisfactorily explained on the basis of casinginterference. The relative productivity was found to be insensitive to spatialarrangement of the perforations.

Introduction
The relative productivity of wells with perforated casing has been treatedmathematically by Muskat. In his treatment the perforations are represented bysmall spheres, thus enabling him to approximate the flow by that to pointsinks. By neglecting interference between the flow into the various spheresrepresenting the perforations, one may deduce the approximate formula (Equation1).
Fig. 1 is a comparison of values calculated from equation (1) with Muskat'svalues. It will be observed that the approximate values are in error by lessthan 2' per cent.
The disturbing effect of the casing on the flow lines is not explicitly takeninto account by Muskat, but he reasons that interference between the flowpatterns from the various point sinks will result in a negligible flow in theregion within the well radius, and that no appreciable error will result fromnot explicitly excluding flow from this region. This line of reasoning is opento question, however, as the flow impedance, in the immediate vicinity of thewell, of a hemispherical cavity in contact with an opening in the casing istwice that of a spherical sink in a continuous sand layer. There will be adifference, moveover, between the flow into a hemispherical cavity and thatinto a circular hole in the casing. This latter difference can best beappreciated by comparing the flow from a semi-infinite medium into ahemispherical cavity at the edge of the medium with the flow out of a circularopening of the same radius as the hemisphere and which is also on the edge ofthe medium.
T.P. 2851
Liquid-Liquid Displacement in Porous Media as Affected by the Liquid-Liquid Viscosity Ratio and Liquid-Liquid Miscibility
Authors: Everett J.P. , Gooch F.W. , Calhoun John C. 
Published: April 2012

Summary
The results of two sets of displacement experiments are reported. In the firstset of experiments various solutions of sugar in water were displaced by othersolutions of sugar in water. In the second set oils were displaced by water.Each set of experiments was performed on a linear system made of cementedsilica sand grains.
These displacement tests were made to evaluate the behavior when the ratio offluid viscosities between the displacing and displaced phases was varied. Afurther consequence of the test results is a comparison between displacementbehavior when the displaced and displacing phases are miscible as with sugarsolutions and when they are immiscible as with oil and water.

Introduction
Buckley and Leverett have presented a theory for the displacement of oil by gasor water based upon the relative permeability concept. This theory presents thedisplacement of oil as occurring in two phases, an initial or primary phasepreceding the breakthrough of the displacing phase and a subordinate orsecondary phase during which both oil and the displacing phase flowsimultaneously through the same porous section. These authors gave the resultsof calculations to show that the percentage of oil displaced during the primaryphase by water drive would be dependent upon the ratio of the viscosity of theoil to that of the water. No experimental evidence was reported by theseauthors to substantiate their theory. Qualitatively, however; it has been foundto be in agreement with many observed field results.
Laboratory investigators have been in general agreement in reporting for air orgas drive a small primary phase of production and a large secondary phase.Reported investigations on water drive have shown instances where both primaryand subordinate phases were important, with the former in general being moresignificant.
T.P. 2787
Critical Analysis of the Effect of Well Density on Recovery Efficiency
Authors: Keller W.O. , Callaway F.H. 
Published: April 2012

Abstract
The various theories as to the well spacing-recovery relationship are reviewedin considerable detail and these theories analyzed in terms of theirconsistency with modern reservoir engineering concepts. It is concluded thatthe well spacing problem must be analyzed in terms of recovery efficiency andthat a positive answer to the relation between well density and recoveryefficiency is not available from direct comparisons of the production historiesof wells and fields.
The results of an engineering analysis designed to permit approximatecalculation of recovery efficiencies as a function of well spacing in adepletion type reservoir from basic reservoir data is presented. Results ofthis type analysis indicate that the effect of well spacing on recoveryefficiency in depletion type reservoirs can be expected to be very small.Limitations of this approach are pointed out, particularly with respect to itsapplication in lenticular reservoirs.
Testing techniques are outlined which should indicate whether or not areservoir is continuous between wells and whether or not satisfactory drainageis being obtained with present spacings. A mass of data of this type indicatescontinuity to exist in most fields.

Introduction
The purpose of this paper is to review critically the engineering aspects ofthe well spacing problem, both from the standpoint of certain concepts and fromthe standpoint of reservoir mechanics. The well spacing problem is primarily aneconomic problem in which the optimum well density for a particular field isthat density which will yield the greatest oil recovery consistent withjustifiable development costs. The well spacing answer in terms of economicconditions, however, is extremely sensitive to the variation in recoveryefficiency with well density. The variation in recovery efficiency with welldensity is properly an engineering problem. Different opinions as to thecorrect answer to this engineering problem is the basis for most of the widedifference in opinion among various members of the industry as to optimum wellspacing. This paper will be confined to the engineering problem of the relationbetween well density and ultimate oil recovery; economic considerationsnecessary for the evaluation of optimum well density for any particular fieldwill not be discussed.
T.P. 2938
Performance of Limestone Reservoirs
Authors: Craze R.C. 
Published: April 2012

Abstract
During the past 20 years, research and development in the study of reservoirbehavior have dealt principally with flow of oil through sandstones. Manyreservoir studies of sand fields have proved valuable in promoting recoveryefficiency.
This paper discusses fundamental principles governing oil and gas productionfrom sandstone and limestone alike and presents the results of investigationsrelating to the application of analytical techniques used for sandstonereservoir studies to the study of limestone reservoir performance. Thecharacteristics of limestone porous systems, porosity-permeabilityrelationships, distribution and occurrence of oil, and characteristics of flowthrough such systems are discussed. Recognition is made of the similarities ordifferences which these factors exhibit in limestone and sandstone systems. Comparisons between operating data for typical limestone and sand reservoirsare presented. It is indicated that the distribution and movement of fluids inand through porous limestones follow the same fundamental principles underlyingsuch processes in sandstones. This fundamental similarity may readily bediscernible in the performance of many limestone reservoirs.
The volumetric balance and unsteady state radial flow equation, the fluiddisplacement equation, use of electrical analogue devices, and other analyticaltechniques to study the behavior of limestone fields appear fundamentallyapplicable, but do require thorough understanding of the properties of theformation, of the fluids, their behavior during flow, and adequate productionoperating data. Need for more complete coring and comprehensive examination ofcore properties is stressed. The results of "active oil" studies, andof flow and interference tests are presented. Well spacing, well completion, and efficient rates of production in limestone reservoirs are brieflydiscussed.

Introduction
Limestone and dolomite reservoirs constitute the largest source of supply ofcrude oil in the world, an estimated 60 per cent of present production comingfrom carbonate reservoirs. In many large geologic provinces such as Mexico, theMiddle East, and more recently Canada, almost all the oil is found in this typeof rock. In the United States, all of the major oil-producing areas exceptCalifornia and Pennsylvania contain oil-bearing carbonate formations. Thediscovery in recent years of large oil reserves in the Silurian, Devonian, andOrdovician formations in West Texas, in addition to the large reserves in thePermian, has accentuated the interest of operators, geologists, and engineersin limestone formations and in the many problems associated with understandingthe performance of these reservoirs. The rapid increase in discovery of oil inlimestone formations and the present-day position of prominence held by thesefields in the production and reserve picture in all parts of the worldemphasize the horizons opened to the reservoir technologist in the field ofgeological and production research.
T.P. 2935
Anomalies in the Measurement of Wetting Liquid Pressure Gradients
Authors: Rose Walter , Greifer Bernard 
Published: April 2012

The purpose of this note is to call attention to a source of difficultywhich can be responsible for inaccurate estimates of wetting liquid pressuregradients in mixture flow experiments of the Hassler type. It has been ourexperience occasionally to observe what were indicated to be negative pressuregradients, and these were regarded as anomalous in the sense that physicallythey seemed to contradict the requirement that the flux be in the direction ofthe potential field.
At first it was thought that our scheme of assembling barriers and coresample led to such asymmetry in the distribution of isobars that the manometricleads at each end of the core were responding to internal pressures (within thecore sample) which could be either positive or negative with respect to eachother, and which in fact might tend to reflect on different effective corelengths in an unpredictable fashion as the wetting liquid saturation waschanged. However, no compelling evidence of this possibility has beenestablished. In addition, we were cognizant of the requirements to be satisfiedin selecting manometric instrumentation to minimize the delay in response ofthe manometer to the differential pressures being measured, and were thusassured that our observations of anomalous pressure gradients could not beexplained by faulty instrumentation.
What we suggest is that if a leak sink occurs in the fluid lines connecting thecore to either side of the differential manometer, errors exceeding 100 percent may result in the estimation of wetting liquid pressure gradient, eventhough the leak is of such small magnitude that its existence would tend to beobscured by evaporation effects. This is because in a system with leaks at thespecified places, the manometer records at steady state the pressure dropacross the manometer barrier elements in addition to the pressure drop acrossthe core sample.
This possibility will be illustrated below analytically and by numericalexample for the special case where the leak occurs on the high pressure side ofthe core, since we are especially desirous to explain the significance of ourobservations of the so-called negative pressure gradients. It will beindicated, however, that leak sinks on the low pressure side of the core canaccount for observations of anomalously high values of pressure gradient, andthat multiple leaks on both sides of the core can provide for some compensationso that the errors in pressure estimation are reduced. However, the major pointto be emphasized is the fact that the impracticality of detecting the smallleak sinks which give rise to the difficulties makes it a complicated task forthe experimenter in a particular case to know with certainty that hisestimation of pressure gradient lies within the limits of error which can betolerated.
T.N. 57
Influence of Different Types of Formation Waters on Disintegration of Cements
Authors: Clark Roscoe C. 
Published: April 2012

Abstract
A study of the effect of various corrosive waters on five different types ofcements indicated that those cements containing less than 5 per cent tricalciumaluminate were the most resistant to corrosion.

Introduction
Oil field experience indicates that some formation waters are excessivelycorrosive to some cements. A study has been made to determine the mostcorrosive waters and the relative resistance of various types of cement tothese corrosive waters.

Procedure
This study of the corrosion of cement was limited to an evaluation of theeffect of various corrosive waters on five different types of cements. Adetermination was made of the types of cements which offer the greatestresistance to corrosion and of the chemical contents of waters found to be themost destructive to cements.
The laboratory tests were conducted by immersing small cylinders of 20 samplesof set cement in various corrosive waters. The initial mixing of most of thecement slurries was done using Tulsa tap water as the mixing water; however, afew of the slurries were mixed using a sulfate water as the mixing water. Whenthe 20 samples had been immersed for a period of nine months, they were removedfrom their corrosive baths, inspected and photographed.
The field tests were conducted by placing ten cement specimens, each containedin a screen wire thimble, in the gas anchors of insert pumps in wells in sixdifferent fields. The specimens were observed whenever it was necessary to pullthe pumps and were returned to the laboratory when deterioration had reached aserious state.

Experimental Results
In both the field and laboratory tests the resistance of the different cementsto corrosion was determined by the condition of the samples and the number ofsamples of each that were in good condition at the end of the immersion period.Table I lists the various cements tested in the order of their resistance tocorrosion with the most resistant at the top and the least resistance at thebottom.
T.N. 59
Carter Reservoir Analyzer Timing Circuit
Authors: Baldwin W.F. 
Published: April 2012

The timing circuit generally employed in Carter Reservoir Behavior Analyzersconsists of a synchronous motor driven cam which actuates a microswitch. Amechanically actuated timer of this type has several inherent disadvantages, among which are the following:The first time interval may not be of uniform length, depending on the exactposition of the cam at the conclusion of a previous run.The positioning adjustments on the microswitch lever arms are critical andrequire periodic readjustment.The mechanical system is subject to wear which will ultimately impair itsaccuracy.
It was therefore considered desirable to devise an alternate method which wouldeliminate these difficulties without introducing others that would be equallytroublesome. This note describes the design of an electronic timing devicewhich has been incorporated in the analyzer constructed by the Field ResearchLaboratories of Magnolia Petroleum Co.
The electronic timer circuit is built around a simple neon glow tube relaxationoscillator, the complete circuit diagram of which is shown in Fig. 1. Theoperation of the circuit is as follows: Condenser C1 is charged to the criticalfiring voltage of the neon glow tube VR-75 by battery B, through resistors R1and R2. When the neon glow tube fires, the condenser C1 is discharged.
T.N. 63
Pressure Behavior in the Woodbine Sand
Authors: Bell John S. , Shepherd J.M. 
Published: April 2012

Abstract
A pressure difference of 280 psi measured initially on opposite sides of themajor fault in the Hawkins Field led to pressure determinations in the Woodbinesand throughout the East Texas basin. Considering the large area, there isunusually good correlation between pressure losses and points of majorwithdrawals, these losses indicating that the basin pressure has beenmaterially reduced by withdrawals, primarily from the East Texas Field andsecondarily from the old fault-line fields of Limestone and Navarro counties, with the pressure loss varying inversely with the log of the distance fromthese two main areas of basin withdrawals to the measurement points. Apparentlyfaults located throughout the basin serve as local blocks to continuouspressure gradients.

Introduction
The pressure anomalies found in the Hawkins Field, Wood County, Texas, shortly after discovery have led to an area-wide investigation of the pressuredistribution within the Woodbine sand of the East Texas basin. These pressureswere obtained by drill-stem tests made for that sole purpose while drillingwildcat wells to deeper horizons. The Woodbine sand of Gulf Cretaceous Age isor has been productive of oil and gas in 42 different fields, with the 28 oilfields currently active having produced 118,000,000 bbl of oil during 1949.With one exception, producing energy for all Woodbine reservoirs has been from water drive provided predominantly by expansion of the tremendousvolume of water contained in the Woodbine sand. This producing mechanism wasrecognized at an early date and was described mathematically by Muskat and bySchilthuis and Hurst in 1934, and these principles were applied to the EastTexas Field performance by Buckley in 1938.
Factual data on the pressure behavior in the Woodbine sand, especially inareas non-productive of oil, have been generally lacking, making estimates ofpressures at various points within the basin dependent upon mathematicalanalyses involving numerous assumptions. Such factual data have been gatheredand are now presented as possible aid to the industry in further analysis ofthe producing mechanism in tile Woodbine sand.
T.P. 3000