bluuebunny/crossref_metadata_2025_split huggingface dataset:
Fluid Saturation in Porous Media by X-Ray Technique
Authors: Laird A.D.K. , Putnam J.A. 
Published: April 2012

Abstract
This paper describes the application of x-ray theory to design procedures inconnection with fluid saturation determinations during fluid flow experimentswith porous media. A reliable and rapid method for calibrating the x-rayapparatus is described. Extension of the method to fluid saturationdeterminations in three-fluid systems is described.

Introduction
In research on oil production problems a method is required which will givequickly the quantity of each component of a fluid flow system present at anycross-section of a porous medium.
The sample of porous medium under investigation is usually referred to as acore. The ratio of the volume of one component to the total fluid volume isdefined as the saturation of the porous medium by that component. This ratio isgenerally given as per cent saturation.
Some means of measuring saturation which have received considerationinclude: electrical conductivity of the fluids; emissions from radioactivetracers dissolved in the fluids; the radioactivity of silver caused byreflection of neutrons from hydrogen atoms in the fluids, the attenuation of amicrowave beam, the diminution and phase shift of ultrasonic wave trains, andthe reduction in intensity of x-ray beams in passing through the fluids.
X-rays have already been used with some success. Since every material has adifferent power to absorb x-rays, the reduction in intensity of an x-ray beamas it passes through a core depends on the fluids present. The strength of theemergent beam can be found by converting its energy into a measurable form suchas heat or ionic current, or by its effect on a photographic plate orfluorescent screen.. The beam strengths could be interpreted as quantities ofknown fluids in the core if, previously, these beam strengths had beenidentified with a known combination of the same fluids. With some fluidcombinations it might be desirable to dissolve powerful x-ray absorbingmaterials in one or more of the fluids, to increase the differences in the beamstrengths for various fluid saturations.
Boyer, Morgan and Muskat have described a method of measuring two componentfluid saturation. One component was air or water; the other, mineral seal oilin which was dissolved 25 per cent by weight of iodobenzene to increase itsabsorbing power. The x-ray source was a tungsten target tube operated at 43 kvpotential. The beam emerging from the core was measured as ionic currentflowing across an air-filled ionization chamber by means of an amplifyingcircuit and galvanometer. Another portion of the beam from the x-ray tube waspassed through a metal plate and measured in another ionization chamber. Thisportion, called the monitor beam, was used as an indication of the performanceof the x-ray tube. The galvanometer readings were calibrated against air-oilcore saturations, gravimetrically determined. The method was apparentlyestablished by experimental means.
T.P. 3169
Neutron Derived Porosity-Influence of Bore Hole Diameter
Authors: Scotty C.B. , Egan E.F. 
Published: April 2012

Introduction
The neutron-gamma log has been used for stratigraphic correlation by the oilindustry for a number of years. In the past few years, the quantitativeapplication of the log to provide information with respect to porosity hasreceived considerable attention. The basic concept of quantitativeinterpretation has been pointed out in the literature. It shall be the purposeof this paper to develop by empirical means a method whereby the relationshipof porosity to neutron-gamma deflection may be predicted for various bore holediameters. This relationship is applicable to the present commerciallyavailable neutron-gamma log run in open hole. Data available at present areinsufficient to establish similar correlations for cased holes. Through thedevelopment of such a correlation, the importance of the various factors whichinfluence the log become evident.

Neutron-Gamma Curve
The logging tool consists of a source of neutrons and a means of detectingand measuring gamma rays, the detector being shielded from the direct emissionfrom the source. The gamma rays reaching the detector have three sources oforigin:the natural gamma radiation emitted by the formations,induced gammaradiation resulting from neutron bombardment,gamma rays emitted by thesource and scattered by the formation.
It has been found that a neutron derived porosity correlation is best forshale-free formations. Under this condition the natural gamma ray radiation isquite low, and therefore, will be neglected in this work.
The induced gamma ray radiation resulting from neutron bombardment ispredominantly a function of the hydrogen atom concentration of the substancepenetrated. Due to the geometry of the presently used system, the neutron-gammacurve indicates low radioactivity opposite high hydrogen concentration and highradioactivity opposite low hydrogen concentration (Figs. 1 and 2). Having acurve which measures hydrogen atom concentration, it follows that if the matrixof the formation penetrated consists only of atoms other than hydrogen, and ifthe fluid filling the pores is either oil or water, the curve should be anindication of porosity (both oil and water have practically the same number ofhydrogen atoms per unit volume). The above criteria for a porosity correlationare fulfilled in clean sandstones and limestones in which the pore volume iscompletely filled with liquids (oil or water), but not in formations containingeither free gas or shale or both.
T.P. 3377
Use of the Automatic Free Piston in Oil Well Production Problems
Authors: McMurry E.D. 
Published: April 2012

Introduction
Before discussing the use of the free piston, it may be well to explainbriefly the type of gas lift valves with which the tool is designed tofunction.
The gas lift valve is nothing more or less than a small back pressureregulator. Its construction consists of an outer housing covering a seamlessmetallic bellows in such a way as to form a sealed pressure vessel or pressuredome. To the bellows is attached a stem, and to this stem is attached a seatingmember. When the valve is run into the hole, a pre-determined pressure chargeis placed in the pressure dome. As shown in Fig. 1 the valve is furnished infour different major assemblies, to accomplish good results in different typesof wells.
The valve is mounted on a pup joint (Fig. 2-a); the complete assembly isentered into the tubing string at the desired location. Each valve is furnishedwith a reverse flow check valve (Fig. 2-b) to eliminate any back wash throughthe mechanism. Valve action is as follows:
At any time the casing pressure is allowed to exceed the pressure forceswithin the pressure dome of the valve, the valve simply opens and passes gasfrom the casing annulus into the tubing. When the casing pressure forces areallowed to bleed to a force less than the pressure force within the dome of thevalve, the valve closes.
With this type of construction, it is possible to open and close the valveor valves at will from the surface, through the medium of the gas pressure inthe casing annulus. The cycle of operation is governed by a time cycle motorvalve, commonly referred to as a gas lift intermitter or gas life surfacecontroller (Fig. 3). In actual practice, after the well is unloaded only onevalve is in operation… all other valves remain in the closed position. Onpre-determined time cycles, it is possible to open and close this operating valve at will, and to pass thedesired amount of gas through this valve whenever needed.
This method of gas lift is widely used and has been found to be veryefficient. However, it has long been known that even greater efficiency wouldbe obtained if it were possible to place a piston between the injected gas andthe fluid head. The free piston which will be discussed here was designed toaccomplish this end and has been found to do so with very satisfactoryresults.
T.P. 3583
Measuring and Interpreting High-Temperature Shear Strengths of Drilling Fluids
Authors: Watkins T.E. , Nelson M.D. 
Published: April 2012

Introduction
Deeper drilling for oil is becoming more and more the rule rather than theexception. With deeper drilling come additional problems, perhaps the greatestbeing those brought on by the higher temperatures encountered down the hole, particularly in the Gulf Coast region of Texas and Louisiana. Temperaturegradients of the order of 1.8? to 2.0?F/100 ft are not unusual, and a gradientof 2.3?/100 ft is found in some areas of Texas. With a mean surface temperatureof 74?F, the following temperatures could be expected for a geothermal gradientof 2.0?F/100 ft: at 10,000 ft, 274?F, 12,000 ft, 314?F; 14,000 ft, 354?F; and16,000 ft, 394?F. Severe gelation of lime-base drilling fluid in wells thathave high bottom hole temperatures has become perhaps the most seriousdifficulty encountered in drilling under such conditions.
Lime-base drilling fluids have been very successfully and widely used in thedrilling of wells in the Gulf Coast region because of their inherent stabilitytoward contaminants, their ability to suppress the swelling dispersion ofbentonitic shales, and their ease of maintenance. The gradual recognition, during the past few years, that these muds were, in themselves, the cause ofmany difficulties experienced in drilling has led to widespread efforts by thedrilling industry to determine the reasons for the failure of these mud systems and to develop mud systems capable of performingsatisfactorily under high-temperature conditions.

Manifestations of High-Temperature Gelation
It is generally possible to recognize the symptoms of high-temperaturegelation early enough that advance predictions can be made of seriousdifficulties in mud control, and the useful life of the drilling fluids can beextended by proper treatment. Following is a list of the manifestations ofhigh-temperature gelation:The drill string ‘takes weight’ while going in the hole after a trip. Inearly stages of high-temperature gelation it is possible to notice a slightreduction in drill string weight as the drill pipe is lowered near the bottomof the hole.Excessive pump pressure is required to start the circulationof drilling fluid at or near the bottom of the hole when going back to bottomafter a trip.
T.P. 3638
Mile Six Pool - An Evaluation of Recovery Efficiency
Authors: Anders E.L. 
Published: April 2012

Abstract
The Mile Six pool is located on the La Brea-Parinas Concession ofInternational Petroleum Co., Ltd., in northwestern Peru on the west coast ofSouth America. The reservoir pressure in this pool has been maintained within200 psi of its initial value throughout its history, and gravity drainage hasplayed an important role in the production behavior. It has now produced 95 percent of its estimated ultimate recovery.
It is estimated that this interesting oil pool will ultimately produce 67per cent of the initial oil in place and that the resulting residual oilsaturation may be as low as 19 per cent of the pore volume (29 per cent of thehydrocarbon pore volume). An evaluation of reservoir rock and fluidcharacteristics and ultimate oil recovery is presented.

Introduction
This study of Mile Six pool was made to evaluate its performance accordingto latest available information. The production performance of this pool hasbeen discussed in various articles in the past, and the reported behavior hasbeen used as an example for application of computation procedures for gravitydrainage depletion and as an illustration of field behavior under gravitydrainage or expanding gas cap drive. There have been wide variations inreported values of initial oil in place, reservoir oil volume factor, connate-water saturation, volume of effective sand, and ultimate recoverybecause of the paucity of reliable basic data. These various factors have beendetermined as accurately as practicable with the latest available information, and this evaluation is presented herein. The production history of Mile Six isan excellent example of gravity drainage depletion with effective pressuremaintenance by gas injection.

General
Mile Six pool was discovered by cable-tool drilling in November, 1927, whenwell 1996 was completed in the Parinas sand. After slow development with cabletools and sporadic production, the pool was opened to continuous production inNovember, 1933, and development was completed with rotary rigs. Pressuremaintenance was started in December, 1933, by returning gas to up structurewells.
Most of the development was completed by 1937, but some additional wellswere drilled in the period 1939–1947, and several old wells were deepened. Atotal of 46 oil and gas wells and 4 dry holes were drilled on approximately7-acre spacing. Of the producers, 21 are now flowing, 2 are pumping, 4 are gasinput wells, 3 are abandoned, 1 is a gas well shut in, and 15 are shut inbecause of non-commercial production or high gas-oil ratio. The locations ofall wells are shown on the map of Fig. 1.
T.P. 3695
Application of Laboratory PVT Data to Reservoir Engineering Problems
Authors: Dodson C.R. , Goodwill D. , Mayer E.H. 
Published: April 2012

Abstract
The paper summarizes the historical background of thepressure-volume-temperature analyses of reservoir fluids, the errors involvedin both the sampling and testing of reservoir fluids, the type of informationrequired of a PVT determination, and the field conditions that limit theapplication of anyone analysis. Particular emphasis is placed on the necessityfor approximating as closely as possible the liberation sequence occurring inthe producing formation, flow string, and surface separators. A combineddifferential and flash or "composite" liberation is suggested as thebest means of approximating this liberation sequence.

Historical Background
Petroleum reservoir engineering commonly is considered to be one of thenewest fields of petroleum science, yet much work of a theoretical andintuitive nature was done many years before the modern techniques of reservoiranalyses were developed.
The period 1910–1924 saw considerable work in the field of reservoirbehavior done by the U. S. Bureau of Mines. This work, although entirelytheoretical, pointed out the importance of gas in the recovery of oil from thereservoir. The statement by J. O. Lewis that 20 per cent or less of theoil originally in place in a pool was recovered from the ground under uncurtailedproduction conditions caused some operators to re-examine and modify theirproduction methods. However, though these works showed methods of productionthat have subsequently resulted in greater oil recoveries, they in general wentunnoticed, even though there was a fear that the nation's petroleum resourceswere being exhausted.
The period 1924–1933 saw the industry take considerably more interest inreservoir behavior because of an unfounded fear of its inability to replace oilreserves, the possibility of government regulation, and the energy of one man, Henry L. Doherty. Doherty aroused heated discussions in the industry concerningconservation. To prove or disprove his theories the first experimental work onthe reservoir behavior of petroleum was undertaken. The papers of Dow andCalkin, Beecher and Parkhurst, and Mills and Heithecker are classics althoughtheir experimental procedures were crude. These papers proved that theproperties of petroleum in the reservoir are quite dissimilar to the propertiesmeasured at the well head. Gas dissolved in the oil phase was recognized ashaving considerable importance as had been predicted by the earliertheorists.
T.P. 3710
Injection of Human Bone Marrow and Mononuclear Cell Extract into Infarcted Mouse Hearts Results in Functional Improvement
Authors: Angeli Franca S , Zhang Yan , Sievers Richard , Jun Kristine , Yim Sarah , Boyle Andrew , Yeghiazarians Yerem 
Published: April 2012

Background:We have previously shown that mouse whole bone marrow cell (BMC) extract results in improvement of cardiac function and decreases scar size in a mouse model of myocardial infarction (MI), in the absence of intact cells. It is not clear if these results are translatable to extracts from human BMC (hBMC) or mononuclear cells (hMNC), which would have significant clinical implications.Methods:Male C57BL/6J (10-12 weeks old) mice were included in this study. MI was created by permanent ligation of the left anterior descending artery. Animals were randomized into three groups to receive ultrasound-guided myocardial injections with either hBMCs extract (n=6), hMNCs extract (n=8) or control with 0.5% bovine serum albumin (BSA) (n=7). Cardiac function was assessed by echocardiography at baseline, 2 and 28 days post-MI. Infarct size and vascularity was assessed at 28 days post-MI.Results:hBMC and hMNC extract preserve cardiac function and result in smaller scar size post-MI when compared with the control group.Conclusions:The current study for the first time reports that hBMC and hMNC extracts improve cardiac function post-MI in a mouse MI model. Further studies are necessary to fully address the potential clinical benefits of these therapies.
Application of Anion Exchange Resin for the Separation of Metals in Tert-butyl Alcohol-Water-Formic Acid Medium
Authors: Rahman Mohammad Arifur , Faruk Mohammad Omar , Alam AM Shafiqul 
Published: April 2012

The use of tertiary butyl alcohol in admixture with formic acid for the selective elution of cations on the ion exchange resin Amberlite IRA-420 in Cl- form is investigated. The elution technique was coupled with absorption spectrometry and atomic absorption spectrophotometry. The distribution coefficients of metal ions were measured in tertiary butyl alcohol -water-formic acid mixture. By applying distribution co-efficient data, the metals from the mixtures have been separated one after another by eluting with tertiary butyl alcohol-water-formic acid solution of different compositions. The average recovery for all separations (n = 18) was within 94.6  98.2 % and the standard deviation for all data was ± 0.96. The developed analytical methodology was successfully applied for the separation and quantification of metal ions in the microgram range from the real samples collecting from natural water and industrial effluents using UV-Visible and AAS techniques.DOI: http://dx.doi.org/10.3329/dujs.v60i1.10329 Dhaka Univ. J. Sci. 60(1): 15-20, 2012 (January)
Continuous Dependence of Fixed Points on Parameters and Initial Conditions
Authors: Islam Md Rezaul , Ferdousi Razina , Ali Md Showkat , Khan MR 
Published: April 2012

The main purpose of the paper is to establish conditions for a continuous dependence of fixed points and an application to non-linear functional differential equation of neutral type have been made.DOI: http://dx.doi.org/10.3329/dujs.v60i1.10330 Dhaka Univ. J. Sci. 60(1): 21-24, 2012 (January)
LSPIHT Algorithm for ECG Data Compression and Transmission for Telemedicine Applications
Authors: Zebin Tahmina , Farook Ekramul , Aman Syeda Zinath , Rafique Shahida 
Published: April 2012

Medical image analysis and data compression are rapidly evolving fields with growing applications in healthcare services e.g. teleradiology, teleconsultation, e-health, telemedicine and statistical analysis of medical data. In this paper, a Layered Set Partitioning in Hierarchical Trees (LSPIHT) algorithm for medical data compression and transmission is presented. In the LSPIHT, the encoded bit streams are divided into a number of layers for transmission and reconstruction. Starting from the base layer, by accumulating bit streams up to different enhancement layers, medical data can be reconstructed with various signal-to-noise ratios (SNRs) and resolutions. Receivers with distinct specifications can then share the same source encoder to reduce the complexity of telecommunication networks for telemedicine applications. The algorithm is compared with other algorithms for encoding ECG data, and analysis shows that the LSPIHT attains better rate-distortion performance and low network complexity than other encoding techniques.DOI: http://dx.doi.org/10.3329/dujs.v60i1.10332 Dhaka Univ. J. Sci. 60(1): 31-36, 2012 (January)
Performance Analysis of a PV Pump Harvesting Rain Water in the Drought Prone Area of Bangladesh
Authors: Reza Khan Mamun , Das Subrata , Mahmood Zahid Hasan 
Published: April 2012

In this paper the performance of a PV driven water pump, without battery storage, for supplemental irrigation by harvesting rainwater is analyzed. A brushless DC motor is used in this work. The worst day, in terms of rainfall, of the month of July has been chosen for data collection. The variation of the flow rate as a function of the PV array power is found to be linear. Head loss is calculated and found greater at higher flow rate. Lower trend of the subsystem efficiency is observed with the increment of the array power. Considering the module efficiency of the manufacturer, the system efficiency is also calculated and found 3.2% as the highest. The amount of water lifted is found to be quite satisfactory for supplemental irrigation.DOI: http://dx.doi.org/10.3329/dujs.v60i1.10333 Dhaka Univ. J. Sci. 60(1): 37-41, 2012 (January)
Photodegradation of Orange Green by Fe(III)Aqua Complex
Authors: Hossain Md Mufazzal , Rasel Md Rashedul Islam , Islam Md Safiqul 
Published: April 2012

The photodegradation of orange green (OG) by excitation of Fe (III)-aqua complexes has been investigated under UV and solar light illumination. The rate of degradation has been found to be strongly influenced by the pH of the solution, initial concentration of Fe(III) and the nature of the light sources. The progress of removal of OG from solution has been monitored by recording the change of absorbance at ?max = 480 nm, (? = 1.27 × 104 L mol-1cm-1 at 30°C), with time. The pH has been varied from 1.2 to 3.5. The initial concentration of Fe (III) was between 9.0 × 10-4 mol L-1 and 2.4 × 10-3 mol L-1. The intensity of the UV artificial source was 14 Wm-2, whereas the average intensity of the solar light during the experiments was about 700 Wm-2. An optimistic result was obtained, when OG was irradiated by solar light. About 92% degradation of 1.5 × 104 mol L-1 OG solution has been done within 70 minutes by photodegradation using Fe(III)-aqua complex at pH 2.5 by UV light whereas about 86% degradation has been recorded by the solar light under the same conditions.DOI: http://dx.doi.org/10.3329/dujs.v60i1.10334 Dhaka Univ. J. Sci. 60(1): 43-46 2012 (January)
Determinants and Status of Vaccination in Bangladesh
Authors: Afzal Nasrin , Zainab Begum 
Published: April 2012

The identification of the characteristics that have an influence on the vaccination coverage of children and the determination of the pattern of such influence are very important since the government can reschedule the policy to immunize each and every child. This paper examines the factors that manipulate the vaccination coverage in terms of five major vaccines using the Bangladesh Demographic and Health Survey (BDHS)-2007 data. The results strongly suggest that mothers education and economic status play a vital role significantly in improving the vaccination coverage. Besides, Khulna and Rajshahi have higher whereas Sylhet and Chittagong have lower immunization coverage than Dhaka. In addition, mothers exposure to media (newspaper, TV or radio) also improves the status of coverage both in the rural and urban areas in Bangladesh.DOI: http://dx.doi.org/10.3329/dujs.v60i1.10336 Dhaka Univ. J. Sci. 60(1): 47-51 2012 (January)