bluuebunny/crossref_metadata_2025_split huggingface dataset:
Fundamental Forces Involved in the Use of Oil Well Packers
Authors: Webber Jack C. 
Published: April 2012

Introduction
The successful use of oil well packers requires, in part, an understanding ofthe pressures which exist at the packer in various applications and anunderstanding of the characteristics of the various types of packers. It iswith these pressures, the resultant forces, and the characteristics of packers, that this paper is primarilyconcerned.
An oil well packer may be defined as a mechanical device for blocking thepassage of fluids in an annular space. In the more usual case, the annularspace is that between the tubing or drill pipe in a well and the casing, andpackers which block such an annular space are broadly referred to as casingpackers. In the other case, the annular space is that between the tubing ordrill pipe and the walls of an open hole, and packers for blocking this spaceare generally called formation packers. While the hydraulics involved areessentially the same for casing and formation packers, a greater variety of conditions areencountered in the use of casing packers and only casing packers will bediscussed.
After a packer has been set and a pressure seal effected between tubing andcasing, the packer is comparable to a piston in a cylinder. Pressures actingupon a piston result in forces which will move the piston unless some means isprovided to prevent such movement.
In the same manner, pressures acting upon a packer will move the packer unlessthere is present a sufficiently great restraining force.

Packer Classifications
Packers may be classified according to the pressure conditions under which theyare capable of blocking the annular space between tubing and casing. Fig. 1shows schematically two types of packers in common use. These packers arecapable of blocking the annular space against the passage of fluids under adifferential pressure of significant magnitude only when the pressure in theannular space above the packing element is greater than the pressure below. Itmay be seen that in Fig. 1-a, slips with teeth which bite into the casing andprevent downward movement are provided. In Fig. 1-b, an anchor preventsdownward movement. In each case, there is only the tubing to prevent upwardmovement when differential pressures act to move the packers upwardly. Packerswhich hold only a significant differential pressure acting downwardly have beenin use since the early days of the oil industry and will hereafter be referredto as conventional type packers.
T.P. 2710
Multiple Condensed Phases in the N-Pentane-Tetralin-Bitumen System
Authors: Billheimer J.S. , Sage B.H. , Lacey W.N. 
Published: April 2012

Abstract
A restricted ternary system made up of n-pentane, tetralin, and a purifiedbitumen was investigated at 70, 160, and 220'F. Most of the experimentalobservations were at atmospheric pressure or at 200 psi. However, someexperimental measurements were carried out at a pressure of approximately 8000psi.
It was found that the purified bitumen was precipitated from its solution ordispersion in tetralin by the addition of n-pentane and that the separationoccurred at lower weight fractions of n-pentane at the lower temperatures. Thebitumen-tetralin solutions show some colloidal characteristics at temperaturesbelow 160'F when near compositions at which the bitumen separates as a solidphase. At states remote from the phase boundaries and at temperatures above160'F these characteristics become less evident. Under these lattercircumstances the mixtures tend to follow the behavior of true solutions, particularly in regard to the approach to heterogeneous equilibrium. Anincrease in pressure appears to increase the solubility of bitumen intetralin-n-pentane solutions. This effect is more pronounced at temperaturesabove 160'F than at lower temperatures.

Introduction
Asphaltic phases of plastic or solid nature have appeared in numerous instancesduring the recovery of petroleum from underground reservoirs. Such depositionsoccurring underground appear to have caused adverse production histories forparticular wells or zones. Because of this field experience, it is desirable tounderstand the factors which influence the formation or separation of theasphaltic phases from petroleum. The problem is unusually complex because thenumber of true components involved is very large and the details of the phasebehavior encountered are difficult to ascertain experimentally.
The literature relating to asphalts, asphaltines, and bitumen is voluminous andwidespread. Only those references which are directly pertinent to the work athand are cited. The separation of an asphaltic phase, hereinafter calledbitumen, from naturally occurring hydrocarbon mixtures has been the subject ofseveral investigations. It has been found that as many as four phases may beproduced from a crude oil by the solution of a natural gas and propane at apressure of 1500 psi and a temperature of 70'F. The separation of bitumen fromsuch naturally occurring mixtures results in at least one liquid phase which issubstantially free of high molecular weight components. The influence of thesolution of lighter hydrocarbons on the separation of bitumen from a Santa FeSprings crude oil has been investigated.
T.P. 2730
Wave Forces Computed for a Typical Offshore Drilling Site
Authors: Horrer Paul L. 
Published: April 2012

Abstract
Costly damage by severe wave attack to many engineering structures hasillustrated the need for a consideration of the nature of wave action in plansfor offshore drilling operations. Using wave data it is possible to answerquestions pertaining to engineering problems such as platform elevation, structure orientation, and expected wave forces. For locations where waverecords are not available a technique can be used to obtain information aboutwave characteristics from past meteorological data and near shore submarinetopography. Forces exerted on structures by waves may be divided into fourparts. A completed study is given in which frequencies of various wave heightsand maximum frictional drag forces are computed for a typical offshore drillingsite.

Introduction
Waves of tremendous proportions accompanying hurricane winds crash againstbreakwaters and other offshore structures causing untold damages. Wave forcesexerted on structures at these times are enormous, as shown by past records ofincidents where massive portions of breakwaters have been broken off and movedby waves. On other similar occasions, whole structures have been unloosed andsmashed or floated away. These incidents, which seem almost incredible, serveto illustrate the great amount of energy contained in large waves, and to showthat this energy results in powerful forces destructive to offshoreinstallations which are not designed sufficiently strong to withstand waveattack.
In the past the expected frequencies of waves having various characteristicshave rarely been considered in the design of structure affected by wave action.As a result, many structures have failed to accomplish the purpose for whichthey were designed or have collapsed under wave attack. Others have beenconstructed to withstand greater wave energy than is ever encountered, withresulting waste of material and construction time.
In this study an analysis is made of the frequencies of waves having differentcharacteristics which affect the plans for offshore drilling installations.After such an analysis the erection of these structures can proceed with lessrisk involved and with more efficiency and economy.
T.P. 2767
The Application of the Laplace Transformation to Flow Problems in Reservoirs
Authors: Van Everdingen A.F. , Hurst W. 
Published: April 2012

Abstract
For several years the authors have felt the need for a source from whichreservoir engineers could obtain fundamental theory and data on the flow offluids through permeable media in the unsteady state. The data on the unsteadystate flow are composed of solutions of the equation
(Equation).
Two sets of solutions of this equation are developed, namely, for "theconstant terminal pressure case" and "the constant terminal ratecase." In the constant terminal pressure case the pressure at the terminalboundary is lowered by unity at zero time, kept constant thereafter, and thecumulative amount of fluid flowing across the boundary is computed, as afunction of the time. In the constant terminal rate case a unit rate ofproduction is made to flow across the terminal boundary (from time zero onward)and the ensuing pressure drop is computed as a function of the time.Considerable effort has been made to compile complete tables from which curvescan be constructed for the constant terminal pressure and constant terminalrate cases, both for finite and infinite reservoirs. These curves can beemployed to reproduce the effect of any pressure or rate history encountered inpractice.
Most of the information is obtained by the help of the Laplacetransformations, which proved to be extremely helpful for analyzing theproblems encountered in fluid flow. The application of this method simplifiesthe more tedious mathematical analyses employed in the past. With the help ofLaplace transformations some original developments were obtained (andpresented) which could not have been easily foreseen by the earliermethods.

Introduction
This paper represents a compilation of the work done over the past few yearson the flow of fluid in porous media. It concerns itself primarily with thetransient conditions prevailing in oil reservoirs during the time they areproduced. The study is limited to conditions where the flow of fluid obeys thediffusivity equation. Multiple-phase fluid flow has not been considered.
T.P. 2732
A Note on the Theoretical Description of Wetting Liquid Relative Permeability Data
Authors: Rose Walter , Wyllie M.R.J. 
Published: April 2012

In a recent technical note, Owen Thornton suggests that wetting liquidrelative permeability may be derived from the relationship:
(Equation 1)
where Pd/Pc is the ratio of displacement pressure to capillary pressure atthe wetting liquid saturation Sw, and I is the resistivity index at thissaturation. Thornton shows that this expression gives values for relativepermeability in good agreement with those experimentally determined byLeverett. We have recently developed another expression for krw, which seemspreferable to Equation 1 since it requires fewer experimental data for itsverification. This equation may be derived in the following manner. Making useof the analogy between mass transfer of fluid in a porous medium and electricalconductivity through the fluid in the same medium, we can postulate a hydraulicformation resistivity factor analogous to an electrical formation resistivityfactor. From Poiseuille's Law the resistivity to flow in a tube of radius R isof the form 8'/R', where ? is the viscosity of the fluid. Similarly, theresistivity to flow in a porous medium of the same dimensions as the tube isgiven by D'Arcy's Law as ?/k, where k is the permeability of the medium. Thehydraulic formation resistivity factor, Ff is thus the quotient of these tworesistivities, or:
(Equation 2)
Gas Hydrates of Carbon Dioxide-Methane Mixtures
Authors: Unruh Carl H. , Katz Donald L. 
Published: April 2012

Abstract
Experimental data are presented for hydrate formation conditions for gasmixtures of carbon dioxide and methane. Equilibrium constants for carbondioxide, defined as the mole fraction of carbon dioxide in the gas phase (drybasis) divided by the mole fraction of carbon dioxide in the hydrate (drybasis), were calculated using the equilibrium constants for methane developedin an earlier paper.

Introduction
A series of papers have been written on gas hydrates, giving temperaturesand pressures at which hydrates would form. Vapor-solid equilibrium constantshave been developed for methane, ethane, propane and iso-butane by which it ispossible to compute for a specific gas mixture the temperature and pressure atwhich hydrates will form.
Carbon dioxide is present in many natural gases in concentrations usuallyfrom 0.1 to 2.0 per cent. It also forms a gas hydrate with water and presumablyenters the solid solution when present with a natural gas which is forming ahydrate. The equilibrium constant giving the ratio of the concentration ofcarbon dioxide in the gas phase to the concentration in the solid phase isrequired for including the effect of the carbon dioxide when computing theconditions for hydrate formation.
Direct determination of the concentration of carbon dioxide in solid hydraterequires a difficult separation to be made. Therefore, this research resortedto the measurement of the temperature and pressure at which specific mixturesof methane and carbon dioxide would form hydrates. From the equilibriumconstants previously mentioned for methane, it is possible to compute theequilibrium constant for carbon dioxide, without measurement of the compositionof the solid phase.
Fig. 1 shows the conditions at which methane and carbon dioxide formhydrates.
T.P. 2578
Relative Permeability To Gas
Authors: Leas W.J. , Jenks J.H. , Russell Charles D. 
Published: April 2012

Abstract
A detailed description is given of an experimental method for determiningrelative permeability of porous media to gas. Results are presented for naturaland synthetic cores. The experimental data for two and three phase systems arecompared. The reproducibility of the equilibrium gas saturation is demonstratedand the effects due to a variation in rate of gas flow are discussed. Anattempt is made to correlate total permeability and rock textural factors withrelative permeability to gas. Capillary pressure curves obtained simultaneouslywith the relative permeability curves are shown to be equivalent to thoseobtained in conventional displacement cells.

Introduction
The advances in petroleum reservoir technology during the past decade havemade increasingly apparent the desirability of a simple, rapid, reliable methodfor obtaining relative permeability data on small cores. Such data are neededin order to study fluid mechanics in porous media and for the more refinedreservoir behavior prediction calculations now under development.
T.P. 2810
Performance Characteristics of a Volumetric Condensate Reservoir
Authors: Allen F.H. , Roe R.P. 
Published: April 2012

Abstract
The performance history of a volumetric gas condensate reservoir ispresented. Curves depict the pressure-production relation and illustrate thephase behavior of the reservoir fluid. This performance is compared tocalculated performance.
This Bacon Lime Reservoir was discovered in 1941 and has been produced tofield separators and gas sales. Reservoir performance has been observed byperiodic bottom hole pressure surveys and companion sample analysis of welleffluents, in addition to gas and condensate production data.
The pressure-production history demonstrates that the reservoir has producedunder volumetric control. The "retrograde" behavior of the reservoirfluid is illustrated by decreasing butanes-plus content of the well effluent, followed by revaporization as the reservoir pressure approaches abandonment.Calculated performance predictions are compared to actual performance and somediscussion offered on apparent discrepancies.

Introduction
Since the late 1930's, many gas condensate reservoirs have been developed, the retrograde theory of phase behavior has been generally accepted, and anumber of cycling programs have been initiated. Numerous technical papers havesince appeared in the literature dealing with the theory and application ofcycling the gas condensate reservoirs. Some cycling operations have nowadvanced to a stage where it is possible to determine performancecharacteristics to a fair degree of accuracy.
Field performance data for gas condensate reservoirs operated by pressuredepletion have not been so extensively reported in the literature, althoughtheir probable behavior has been discussed in explanation of the retrogradetheory. It is the purpose of this paper to compare calculated theoreticalreservoir performance with field observations and well stream analyses whichhave been obtained throughout the practical producing life of a smallvolumetric gas condensate reservoir.
The reservoir under study is the Bacon Lime Zone of a field located in EastTexas. The Bacon Lime occurs in the Lower Glen Rose Formation of CretaceousAge.
T.P. 2708
The Estimation of Permeability and Reservoir Pressure From Bottom Hole Pressure Build-Up Characteristics
Authors: Miller C.C. , Dyes A.B. , Hutchinson C.A. 
Published: April 2012

Abstract
This paper presents a simple and practical method for the estimation ofeffective permeability and reservoir pressures from the rise in bottom holepressure when a well is shut in. The equations on which the method is basedconsider a stabilized well producing from a uniform formation when flow is shutoff at the sand face followed by the unsteady state flow of a compressibleliquid from regions far from a well to points closer in during the build-upperiod. An approximation for extending the method for two-phase flow in thereservoir is also presented.
In order to compare the effects of extremes in the conditions existing atthe external boundary of the reservoir, two general equations defining thebuild-up characteristics of the reservoir are shown: first, for a reservoirwith constant pressure maintained at the radius of drainage, and second, for areservoir with no influx over the radius of drainage. These equations definethe build-up characteristics for the shut-in well as functions of time, thepermeability and porosity of the drainage area, the viscosity andcompressibility of the fluid flowing, the production rate prior to shut-in, andthe radius of drainage of the well.
When a well is shut in at the surface, rather than at the sand face, flowwill continue into the well bore after shut-in due to the compressibility ofthe fluids in the bore. The effect upon the build-up characteristics of thisflow into the well after shut-in has been studied by means of the electricalanalyzer. From the basic relationships and consideration of the limitations dueto continued flow after shut.in, methods have been developed for the estimationof the effective permeability of an area from the plot of the build-upcharacteristics of the well producing that area.
T.P. 2849
The Microlog - A New Electrical Logging Method for Detailed Determination of Permeable Beds
Authors: Doll H.G. 
Published: April 2012

Abstract
A new electrical logging method is described which measures the resistivity ofsmall volumes of material near and behind the wall of the bore holes. The verysmall electrode systems used are supported in the face of the flexibleinsulator pad of appropriate dimension maintained in contact with the wall. Themeasurements are recorded simultaneously with two different electrodespacings.
This method provides a very detailed record of the formations and particularlyof the permeable beds traversed by the bore holes.
The application of MicroLog to the location of permeable zones within compactformations, such as limestone, and to the determination of the amount of sandexisting in sequences of thin shale and sand streaks is discussed.
The possibility of quantitative determination, providing a step toward theevaluation of formation porosity and mud cake thickness, is also examined.
Field examples illustrate the essential features of the method.

Introduction
In conventional electrical logging, the spontaneous potential (SP) log is usedto delineate the permeable beds, and the resistivity logs are used primarily toprovide indications concerning the fluid content of the beds.
When the formations are much more resistive than the mud, as happens, forexample, in limestone fields, the SP currents are short-circuited by the moreconductive mud column, with the result that the SP log is quite rounded. Inthat case, the SP log generally gives the approximate location of the permeableformations but it cannot be used for an accurate determination of theboundaries of each permeable bed.
Solutions for the problem of obtaining a better determination of the permeablebeds in limestone fields were developed from two angles. One approach consistedin improvements to the logging of the SP, as given by Selective SP logging andStatic SP logging. These new methods, which have been described in an earlierpaper, give good results when the mud is not too salty, but they are still in asomewhat experimental stage, mostly because the development efforts have latelybeen concentrated on another approach to the problem, i.e., the MicroLog.
T.P. 2880
Improvements in the X-Ray Saturation Technique of Studying Fluid Flow
Authors: Morgan F. , McDowell J.M. , Doty E.C. 
Published: April 2012

Abstract
Improvements in the X-ray method of measuring liquid saturation and saturationdistribution are presented. Two identical direct current amplifiers have beenadded to measure continuously the intensities of the X-ray tube output and thebeam which has passed through the core under test. The ratio of theseintensities is automatically recorded on a modified Brown Electronik Recorder.Arrangements have been made to drive the core automatically and in synchronismwith the recorder chart so as to give a continuous curve showing the variationof liquid saturation along the length of the core. By determining the ratio ofthe two X-ray beam intensities simultaneously the measurements are madeessentially independent of small fluctuation in voltage and current supplied tothe tube. This improved technique has been used for investigating the fluiddistribution along the length of cores and core assemblies when one fluid isdisplaced by another. Typical results of these studies are shown.

Introduction
In a previous publication a method was described for measuring the oilsaturation in cores which was based on the absorption of X-rays by the fluidcontent of the core. While that technique is capable of yielding accurateresults, the original apparatus was not especially convenient for determiningthe fluid distribution along the length of a core. This was primarily due tothe slow response of the amplifier and galvanometer and the necessity of makinga point by point survey of the material under investigation. It was, therefore, not only possible for sections of the core having a variable or unusualsaturation distribution to escape observation entirely, but changes in outputof the X-ray generator between readings on the unknown and the monitorintroduced errors in the measurements that could be avoided only by furtherstabilization of the source or by taking a large number of readings.
This paper describes a method and apparatus for recording continuously andautomatically the intensity of the X-ray beam that is transmitted by a core.The variation of saturation with time at a given section of the core may thusbe found, or by scanning the core by driving it in synchronism with therecorder the saturation distribution may readily be determined.
T.P. 2881