bluuebunny/crossref_metadata_2025 huggingface dataset:
EKSPERIMENTASI MODEL PEMBELAJARAN KOOPERATIF TIPE TEAMS GAMES TOURNAMENTS DAN TEAM ASSISTED INDIVIDUALIZATION PADA MATERI GARIS DAN SUDUT DITINJAU DARI KECERDASAN EMOSIONAL SISWA KELAS VII SMP NEGERI SE-KABUPATEN MAGETAN TAHUN PELAJARAN 2013/2014
Authors: Annurwanda Pradipta , Mardiyana Mardiyana , Sari S Dewi Retno
Published: February 2020

Abstract: This aim of the research was to know the effect of learning models on mathematics achievement viewed from the student emotional intelligences. The learning model compared were TGT, TAI and direct learning. The type of the research was a quasi-experimental. The population was all of student seventh grade of junior high school in Magetan regency on academic year 2013/2014. The sampling technique by using a stratified cluster random sampling. The size of the sample was 252 students with 85 students as experimental class I, 86 students as experimental class II, 81 students as control class. The data collections were taken by document, questionnaire and test method. Hypothesis testing was performed by using an unbalanced two way analysis of variance. The conclusions of  the research were as follows: (1) TGT learning model give better mathematics achievement than TAI and direct learning model, TAI learning model give an equal mathematics achievement to direct learning model, (2) the high level emotional intelligence students have an equal mathematics achievement to the middle level emotional intelligence students, the high level emotional intelligence students have better mathematics achievement than the low level emotional intelligence students, the middle level emotional intelligence students have better mathematics achievement than the low level emotional intelligence students, (3) for the high level emotional intelligence students, TGT, TAI and direct learning models give the same mathematics achievement, for the middle level emotional intelligence students, TGT learning model give the same mathematics achievement as TAI and direct learning model, direct learning model give better mathematics achivement than TAI learning model, for the low level emotional intelligence students, TGT learning model give the same mathematics achievement as TAI learning model, TGT learning model give better mathematics achievement than direct learning model, TAI learning model give the same mathematics achievement as direct learning model, (4) on the TGT and TAI learning models, students in each level of emotional intelligence have the same mathematics achievement, for student with direct learning model, the high level emotional intelligence students have the same mathematics achievement as middle and low level emotional intelligence students, the middle level emotional intelligence students have better mathematics achievement than low level emotional intelligence students.

Keywords: Teams Games Tournaments, Team Assisted Individualization, direct learning, emotional intelligence.
Osmanlı Diplomasisinde Bir Kaynak: Nâmei -Hümâyûn Defterleri ve 7 Numaralı Defterin Tanıtımı
Authors: SARI Havvanur
Published: February 2020

Osmanlı arşivinin en önemli defter serilerinden biri olan nâme-i hümâyûnlar, Osmanlı padişahları tarafından, bağımsız ya da Osmanlı Devleti’ne bağlı, yarı bağımsız hükümdarlara gönderilen mektupları ifade etmek için kullanılmaktadır. Nâme-i hümâyûnlarda Osmanlı Devleti’nin diğer dış devletlerle olan münasebetleri ve onlara karşı izlediği politikalarla ilgili bilgiler bulunmaktadır. Bu açıdan birinci elden kaynak niteliğindeki bilgilerin tespiti için bu tür belgelerin incelenmesi ve değerlendirilmesi gerekmektedir. Araştırma da 1720 -1741 yılları arasında kaleme alınmış olan 7 Numaralı Nâme-i Hümâyûn Defterinin özellikleri, kapsamı ve içeriği üzerinde durulmuştur. Ayrıca araştırmada nâme-i hümâyûn defterlerinin Osmanlı diplomasisindeki kaynak değerinin nasıl olduğu sorusunun cevabı verilmiştir. Çalışmada ki değerlendirmeler için 7 Numaralı Nâme-i Hümâyûn defteri transkiribe edilmek suretiyle, belgelerin genel özellikleri ortaya çıkartılmıştır. Ardından bunlardan bir belge somut bir örnek olması açısından incelenerek, diplomatik açıdan tahlil edilmiştir. Çalışmada yapılan değerlendirmeler neticesinde nâme-i hümâyûn defterlerinin içeriğinde Osmanlı padişahlarının cülus haberi, savaş ve barış kararları, atamalar gibi bilgilerin varlığı tespit edilmiş olup nâmelerin yazılış bakımından beşaretnâme, fetihnâme ve tehditnâme olmak üzere üç kısma ayrıldığı belirtilmiştir. İlgili tespit ve değerlendirmeler için konuyla ilgili başlıca araştırma eserlerinden de yararlanılmıştır. Araştırma sonucunda elde edilen bulgular sonucunda Nâme-i Hümâyûn defterinin Osmanlı diplomasisinin önemli kaynaklarından birisi olduğu ve defterde toplam 398 adet yazışmanın gerçekleştiği bilgisine ulaşılmıştır. Ayrıca defterde en çok yazışmanın gerçekleştiği devletlerin Rusya, İran ve Kırım olduğu da tespit edilmiştir.
DESTİNASYON PAZARLAMA ARAÇLARINDAN WEB SİTELERİNİN DEĞERLENDİRİLMESİNE YÖNELİK NİTEL BİR ARAŞTIRMA: AKDENİZ DESTİNASYONLARI ÖRNEĞİ
Authors: ÜNAL Aydın , ÇELEN Onur
Published: February 2020

Modern bilgi çağı ve pazarlama anlayışında meydana gelen gelişmeler insanları, hayatın her alanında bilgi ve iletişim teknolojilerini, akıllı ürünleri, mobil uygulamaları, web sitelerini, sosyal medya, vb. araçları kullanmaya yöneltmektedir. Benzer şekilde turistlerin hızla artan turistik bilgi arayışları ve turizm pazarlarında yaşanan yoğun rekabet, destinasyon pazarlamacılarını, maliyet avantajı sağlamak, güncel ve sürekli bilgi sunulabilmek, geniş kitlelere erişim imkânı sağlamak gibi çeşitli nedenlerden ötürü ilgili araçlardan yararlanmak durumunda bırakmaktadır. Bu araçlardan web siteleri ise sağladıkları avantajlar ile turistlerin ve destinasyon pazarlamacılarının gereksinimlerini karşılamada öne çıkmaktadırlar. Bu çalışmada da Türkiye turizminin önemli bileşenlerinden Akdeniz Bölgesi destinasyonlarının (8 il ve 103 ilçe) web sitelerinin belirli kriterler çerçevesinde değerlendirilmesi ve mevcut durumun ortaya konması amaçlanmaktadır. Web sitesi bileşenlerini ve özelliklerini betimlemek üzere nitel araştırma yöntemlerinden biri olan içerik analiz tekniğinden yararlanılmıştır. Yapılan analizler neticesinde; Akdeniz Bölgesi destinasyonlarının %91’inin kendilerine ait bir web sitelerinin olmadığı ve bağlı bulundukları valilik, belediye ve il kültür turizm müdürlüklerinde de detaylı bilgilerinin bulunmadığı belirlenmiştir. Web sitesine sahip olan destinasyonların ise web sitelerinin değerlendirildiği bileşenler ve özellikler bağlamında yetersiz oldukları sonucuna ulaşılmıştır.
Spacing of Natural Gas Wells
Authors: Craze R.C.
Published: February 2020

Published in Petroleum Transactions, AIME, Volume 213, 1958, pages 213–219.

The discovery of a new gas reservoir demands that the planning of a sound well-spacing program be initiated early in the development stage. It is the purpose of this discussion to illustrate by actual field examples the application of basic well-spacing principles, previously developed for oil reservoirs, to the problem of well spacing in natural gas fields. These studies are presented for the field use of geologists and engineers who are concerned with the initial planning of the proper development of the newly discovered gas reservoir.

Introduction

The phenomenal growth of a vigorous natural gas industry emphasizes the increasing importance of natural gas as a source of energy, fuel, and raw materials to our nation's economy. Since 1945 marketed production of natural gas for the U.S. has increased 2½ times to a record high of 10.6 trillion cu ft during 1957. As major participants in the gas industry, we share an added interest to develop and produce our natural gas reserves with constantly improved efficiency.

The subject of well spacing is vitally important to the gas industry, for the well itself plays a significant role in the development of the natural gas reservoir and in control of the recovery process. Maximum utilization of wells is an integral part of sound conservation practices.

The discovery of a new gas reservoir demands that careful choice of well location and well spacing be made and that the planning of a sound well spacing program be initiated early on the development stage. With the drilling of the first development well, efforts of the geologist and engineer must be directed toward acquisition of adequate technical evidence upon which a firm recommendation for a spacing program may be based. With this technical appraisal as a foundation, operators and state regulatory agencies jointly can go far in providing a framework for sound development of gas fields to achieve a program of conservation that avoids the unnecessary well.
Generalized Newtonian (Pseudoplastic) Flow in Stationary Pipes and Annuli
Authors: Savins J.G.
Published: February 2020

Published in Petroleum Transactions, AIME, Volume 213, 1958, pages 325–332.

Introduction

The first paper in this series outlined practical methods for applying the theory of steady-state flow of an ideal Bingham plastic liquid through a circular pipe and axially through a stationary concentric annulus to the engineering analysis of friction loss problems.

In the present paper the properties of another useful rheological model, the pseudoplastic generalized Newtonian liquid, are considered. The terminology applied to the rheological models is derived from the following classification of rheological models. The term "generalized Newtonian" is a class designation applied to models which do not have yield points but which exhibit a dependence on shear rate. The term "pseudoplastic" applies to a sub-group of models within this class which exhibit a decrease in "viscosity" with increasing shear rate. The term "power model" refers to a mathematical model proposed for describing the behavior of the pseudoplastic liquid. This model is of interest since certain of the salt saturated, oil emulsion, and "low solids" drilling fluids, inverted emulsion- and oil-base drilling fluids, aqueous gels, gelled crudes and blocking agents employed in hydraulic fracturing operations are of this type.

The present treatment considers the equations describing steady-state Poiseuille flow through a circular pipe and a stationary concentric annulus, and Couette flow between concentric rotating cylinders for a particular pseudoplastic model. As in the previous paper it is demonstrated how these equations can be applied to engineering calculations of friction losses. Graphical procedures for recovering the various flow curves and example calculations are included. A method for simplifying turbulent-flow correlations is also proposed.
Laboratory Studies of Five-Spot Waterflood Performance
Authors: Rapoport L.A. , Carpenter C.W. , Leas W.J.
Published: February 2020

Published in Petroleum Transactions, AIME, Volume 213, 1958, pages 113–120.

A program of scaled flow model experiments has been undertaken to study the performance of five-spot water floods. The modeling procedures are discussed and the construction and operation of the flow models are described. The tests were specifically designed to investigate the effects of injection rate and of oil-to-water viscosity ratio on oil recovery. The areal sweep of five-spot water floods was also studied, and direct comparisons between five-spot and linear flooding behavior have been established to permit better utilization of core analysis results for purposes of field waterflood evaluations.

Introduction

For a long time reservoir engineering procedures have been confined to the consideration of idealized, one-dimensional or linear systems. However, direct application of the linear waterflood mechanism to the evaluation of actual field performance is justifiable only for the purposes of rough approximation. To obtain a realistic analysis of field behavior, it is necessary to account for reservoir geometry and well distribution, and to take into consideration the configuration of the flow of fluids between injection and producing wells.

In the past it has been attempted to account for the complex nature of the fluid movement in the reservoir by associating each well pattern with a certain "sweep-efficiency constant", e.g., a sweep efficiency of 72 per cent for the conventional five-spot pattern. More recently, methods of waterflood evaluation have been improved by the introduction of variable sweep-efficiency factors, defining the areal coverage as a function of cumulative water injection and viscosity or "mobility" ratio. These variable sweep-efficiency factors, derived from miscible fluid displacement experiments, require the assumption of piston-like displacement of oil by water. This implies that only one fluid, either oil or water, is moving at anyone point of the reservoir at any moment.
A Laboratory Study of Oil Recovery by Solution Gas Drive
Authors: Handy L.L.
Published: February 2020

Published in Petroleum Transactions, AIME, Volume 213, 1958, pages 310–315.

Introduction

Many differences can be imagined between gas-oil flow in which the gas is supplied at the face of the core and gas-oil flow in which the flowing gas was originally dissolved in the oil. If capillary pressure characteristics and flow requirements control gas saturation distribution, the gas would be expected to be located at preferred sites within the porous medium as determined by pore sizes. On the other hand, during solution gas drive the gas first appears as bubbles through a nucleation process. Nothing in self-nucleation theory specifies at which sites the first bubbles should be formed. In all probability they will be randomly distributed throughout the porous medium. Furthermore, it is not at all certain that even at low rates of production the gas will redistribute itself after nucleation to the channels normally occupied by gas in simple gas flow.

Stewart, et al, have shown that at least for some limestone samples, oil recoveries could not be predicted for all rates of production using anyone set of relative gas and oil permeabilities. An important factor in controlling recoveries during solution gas drive was the rate of bubble formation, higher rates giving higher recoveries. Stewart, et al, attributed the increase in recovery to a better distribution of the gas phase in heterogeneous limestone samples than is obtained by simple external gas drive. Differences in recovery from these causes were not reported for sandstone cores.

In the experiments to be reported here, oil recovery, pressure and producing GOR history were measured during solution gas drive for a 5-ft sandstone core. The results were compared with predictions from the Muskat method for computing solution gas-drive behavior using external gas-drive relative permeability. The effects of changing the rate of production and oil viscosity were studied.

At high laboratory rates of average pressure decline, two observations were made which would not have been predicted by Muskat's depletion theory:oil recovery increased with increasing rate of production for a given viscosity oil, andoil recovery increased with increasing oil viscosity for a given high rate of production.

Both of these observations are explained as consequences of diffusion control of gas saturations superimposed on the normal gas-oil flow requirements.
Streaming Potential and the SP Log
Authors: Gondouin M. , Scala C.
Published: February 2020

Published in Petroleum Transactions, AIME, Volume 213, 1958, pages 170–179.

Published laboratory data have established that very significant streaming potentials can exist across mud cakes subjected to pressure differentials such as exist between a mud column and formation fluids. Since shale is similar in kind and in properties to a well-formed mud cake, it appeared possible that streaming potentials might also arise across shales. A practical consequence would be that the streaming potential contribution to the SP would be smaller than might otherwise be assumed since the SP is measured with respect to the "shale base line". The resultant contribution would be the difference between the streaming potential across the shale and that across the mud cake.

In order to investigate this possibility, a laboratory apparatus was devised for measuring streaming potentials under pressure condition normally encountered in wells. Reported data on streaming potentials across mud cakes were verified. More important, appreciable streaming potentials were found across shale samples. As in the case of mud cakes, the shale potentials varied with the concentration and nature of the impregnating electrolyte. Dependence on pressure was in a different relation than that for mud cakes, possibly because of the lower compressibility of shales. The differences in streaming potentials between the shales and mud cakes were generally small, although they might vary considerably in practice depending on the relative electrokinetic properties of the particular shale-mud cake combination. A "poorly effective" shale with a "very effective mud cake" would produce the largest negative addition to the electrochemical component of the SP.Results of field experiments with pressurized wells were considered in the light of the laboratory results.

Introduction

Field experiments wherein the pressure of the mud column in a borehole was varied have often indicated the presence of a streaming potential, but its magnitude was not easily predictable and its sign sometimes changed from one formation to another in the same well. In the interpretation of SP logs from standard surveys, nevertheless, the correct value of Rw is very frequently obtained, within the limits of field accuracy, using only the simple electrochemical expression of the SP provided that proper corrections are made for bed thickness, ion activity, etc.
Departure Curves for the Self-Potential Log
Authors: Worthington A.E. , Meldau R.F.
Published: February 2020

Published in Petroleum Transactions, AIME, Volume 213, 1958, pages 11–16.

An analog computer study was made of the reduction of the magnitude of the SP by formation geometry and resistivity effects. Practical field situations were studied. The analog data were converted to the form of departure charts. These charts may be used to determine the reduction in the SP due to the above effects with good precision.

Introduction

Quantitative interpretation of the SP log in terms of formation water resistivity is presently based on the premise that the observed SP is equal to the electrochemical potential developed across a shale between the mud filtrate and the formation water. This procedure inherently assumes that, first, no electrokinetic (streaming) potential is present, and, second, that the SP is not reduced by resistivity or geometry effects in the formation.

The Analog Model

The analog model used for this study was the Guyod Analog Computer which originally was designed and built for resistivity log departure curve studies. It consists of a two-dimensional mesh of resistors, with the vertical mesh corresponding linearly to vertical distance along the borehole, and the horizontal mesh corresponding to radial distance from the borehole axis. By proper choice of horizontal resistor values, a three-dimensional, axially symmetric, borehole-formation problem can be modeled with this two-dimensional array. These and other details of the model are contained in a paper by H. Guyod.

The geometry used for the SP studies with the analog is depicted in Fig. 1. This configuration has a horizontal plane of symmetry, and, hence, the model, and the following discussion, need only to be concerned with one quadrant such as shown in Fig. 2. A further simplification arises by considering that both the natural potential sources and those used in the model have fixed internal impedance. Therefore, the current flows produced by these sources can be separated and studied independently (i.e., the superposition theorem can be applied).
The Cutting Carrying Capacity of Air at Pressures Above Atmospheric
Authors: Gray Kenneth E.
Published: February 2020

Published in Petroleum Transactions, AIME, Volume 213, 1958, pages 180–185.

The turbulent flow drag coefficients, or friction factors, have been experimentally determined for the cuttings normally encountered in drilling operations.

The gas law and average drag coefficients for characteristically flat particles (limestones and shales) and for angular to sub-rounded particles (sandstones) were used to extend Newton's equation to a more useful form. The resulting equations are expressions for the slip velocity of a particle as a function of the particle size and shape, the bottom-hole injection pressure, and the bottom-hole temperature.

The velocities necessary to lift actual rock cuttings as observed in the laboratory were compared with velocities predicted from the derived equations. Results indicate that there is no single correct circulating velocity and that the commonly used 3,000 ft/min linear velocity may be sufficient to lift only very small particles.

Introduction

A promising departure from rotary hydraulic drilling is air or gas drilling. In many instances the rate of penetration and bit life increases resulting from this method have been very substantial. Further the application of air drilling in areas of lost circulation or water sensitive pay zones has been highly successful.

Purpose

For the drilling contractor, the practical question remains, "How much air pressure and volume should I have?" It is necessary to have a reasonable knowledge of the air velocities and pressures required in air drilling operations for the proper design and most advantageous use of surface equipment and for adequate removal of cuttings from the borehole. Based on experience, most operators agree that at least 3,000 ft/min linear velocity is necessary for satisfactory hole cleaning.

It was the purpose of this investigation to evaluate the drag coefficients, or friction factors, for the cuttings normally encountered in drilling operations, i.e., sandstones, limestones and shales, and to utilize the values obtained to develop an expression for the minimum velocities and pressures (hence the volumes) necessary to lift these cuttings.
Use of Chemicals to Maintain Clear Water for Drilling
Authors: Gallus J.P. , Lummus J.L. , Fox J.E.
Published: February 2020

Published in Petroleum Transactions, AIME, Volume 213, 1958, pages 70–75.

Fresh water or brine drilling fluids may be kept free of suspended drilled solids by the addition of a water soluble acrylamide-carboxylic acid copolymer at the flowline. Addition of from .01 to 0.2 lb/bbl of the polymer solution to drilling fluids containing less than 5 per cent clay solids by weight causes the solids to flocculate and settle rapidly to the bottom of the pits. Solutions of the polymer injected at the pump suction reduce the loss of water to permeable formations without impairing the permeability to oil. The use of drilling fluids clarified with the polymer has resulted in increased drilling rates, extended bit life, and lower drilling fluid costs.

Introduction

Field experience and the results of a number of investigations have established that the accumulation of solids in drilling fluid reduces drilling rate. Drilling with water makes possible higher drilling rates than can be achieved with mud but in many areas drilling with water may not be feasible because of the possibility of encountering high formation pressures or hydratable formations. To combat these conditions, the drilling fluid must possess certain physical properties such as viscosity, density, fluid loss, etc., which require the presence of solids.

The current trend in drilling fluid treatment is to maintain as low a percentage of solids as is possible without harm fully affecting the mud properties needed for drilling. Mechanical separating devices such as wet cyclones and decanting-type centrifuges are proving to be an economical means of controlling the percentage of solids and thereby maintaining low solids muds. Also, special muds have been developed for the purpose of retarding the hydration of drilled solids so that they may be more easily removed by shale shakers or settling pits.

In some areas, such as West Texas, the characteristics of some formations will permit drilling with water. However, because of the dispersion of drilled solids, it is usually not possible to maintain clear water even with the aid of mechanical separators, or by utilizing large settling pits. For this reason the commonly used term "water drilling" is a misnomer since the water usually contains some solids.
Effect of Pressure on Rock Drillability
Authors: Eckel John R.
Published: February 2020

Published in Petroleum Transactions, AIME, Volume 213, 1958, pages 1–6.

A laboratory drilling rig has been devised and placed in operation which permits the application of hydrostatic, terrastatic, and formation pore pressures to a rock sample for drilling under controlled conditions. Calibrated tests of this equipment indicate qualitative agreement with field results oil the effect of weight on bit, rotary speed, and rate of circulation on drilling rate. Tests under pressure, using water and air as the drilling fluids, indicate that when drilling saturated limestone samples, a pressure differential between hydrostatic and formation pressure is the only pressure which affects drilling rate. A differential in either direction causes a reduction in rate, but the same differential from the wellbore into the formation causes the greater reduction. Also, in limestone, air favorably affected drilling rate only when compared to water at high hydrostatic pressure, all other conditions remaining constant. Large increases in drilling rate with air could be obtained in the laboratory only while drilling a shale, which offered a limited permeability to nitrogen and which could be drilled with a differential from the formation into the wellbore. In general, the magnitude of the changes due to the pressure effect were small coin pared to changes in drilling rate obtainable by changing either bit weight or rotary speed.

In the course of Humble's drilling research program, the desirability of investigating several factors which lend themselves to laboratory rather than field study became obvious. Principal reasons for this are the expense involved in field studies and the difficulty of exercising the required degree of control. Of primary importance are investigations of the effect of fluid properties on drilling rate, the effect of pressure on rock drillability, and a study of the fundamental mechanics of rock failure and chip generation.

Several years ago some work in the laboratory on the effect of mud properties on drilling rate was reported to the API, but the completion of this work and the investigation of the other variables affecting drilling rate required equipment somewhat more elaborate than that used on these earlier tests. This equipment has been assembled to form Humble's Drilling Engineering laboratory.
Comparison Between the Predicted and Actual Production History of a Condensate Reservoir
Authors: Rodgers J.K. , Harrison N.H. , Regier S.
Published: February 2020

Published in Petroleum Transactions, AIME, Volume 213, 1958, pages 127–131.

This paper presents comparisons of data obtained from a laboratory reservoir study and from a calculated behavior prediction with the actual production history of a condensate reservoir.

A small non-commercial discovery was depleted under closely controlled conditions and the well fluids were sampled at frequent intervals. Data on the reservoir and production variables were accumulated on a fixed schedule. A laboratory reservoir study was made using the initial well fluid samples as charging stock. The production procedures and operating conditions were held constant throughout the study wherever possible and in general paralleled the field work. The well fluid compositions and the cumulative recoveries as a function of the reservoir pressure were also calculated using conventional flash vaporization procedures and equilibrium constants.

Comparisons based on the composition of the well fluid show good agreement, the laboratory study agreeing within experimental accuracy with the field work and the calculated data comparing equally well. The gas-oil ratios are also in good agreement, but with somewhat greater deviations at the higher pressures.

In the over-all picture, it is believed that a model study can predict within experimental accuracy the production history of a condensate reservoir. Better equilibrium constants for the heavier hydrocarbons are needed in order to attain improved composition accuracy by calculation.

Introduction

In Aug., 1955, a gas condensate well was completed in San Juan County, Utah, that was initially thought capable of good commercial production. These conclusions were derived principally from core data and electric logs, which indicated good permeability, porosity and gas content. However, after the usual series of potential tests it was found that the reservoir pressure had declined some 22 per cent, and it was obvious that the zone tapped was but a small pocket or trap.

It became apparent that, with a controlled depletion of a small reservoir, a unique opportunity was available to compare laboratory and calculated studies with an actual field depletion and to further the present knowledge of condensate reservoirs.
Hydraulic Fracturing - Fracture Flow Capacity vs Well Productivity
Authors: van Poollen H.K. , Tinsley John M. , Saunders Calvin D.
Published: February 2020

Published in Petroleum Transactions, AIME, Volume 213, 1958, pages 91–95.

In the past few years much consideration has been given to the evaluation of the effect of hydraulic fracturing on the productivity of wells. Generally, these studies included the evaluation of fracturing materials, fracture extension and formation damage due to the use of various fracturing fluids. Only little consideration has been given to the characteristics, and in particular the flow capacity, of the fracture itself and its effect on well productivity.

This paper presents the results of laboratory investigations pointed toward the evaluation of the efficiency of various fractures with special emphasis on the flow capacity of these fractures. Data presented in this paper are the results of both an electrical model study and physical testing. Under consideration are (1) effect of overflush, (2) premature production of well after treatment,(3) "tailing-in" with coarse sand near the end of the treatment,(4) effect of propping agent size and concentration, (5) reduction in effective fracture permeability caused by formation caused by formation fines, silt and clays, and (6) effect of various fluids on formation strength and competency.

The results of this investigation indicate that the flow capacity of a fracture is affected by any or all of the various parameters mentioned above. The authors believe that a better understanding and utilization of these factors should result in more efficient formation fracturing.

Introduction

Hydraulic fracturing has become almost a standard practice of many companies for stimulating production from old and new wells. Although most companies utilize this service, techniques of application vary widely between companies and areas.

Probably too often when a well in an area responds favorably to a particular technique all future wells in the same area are treated in a similar manner. Possibly a modification of the technique would result in a further production increase. Variables, of which many are extremely difficult to evaluate from field results, hamper the selection of procedure changes.
Properties of Cementing Compositions at Elevated Temperatures and Pressure
Authors: Carter Greg , Smith Dwight K.
Published: February 2020

Published in Petroleum Transactions, AIME, Volume 213, 1958, pages 20–27.

Studies have been conducted on the properties of many deep well cementing compositions to determine their strength behavior over curing periods to 180 days at elevated temperatures and 3,000 psi pressure. This pressure results in essentially the same compressive strength as that obtained with much higher pressures in accordance with the findings of an API subcommittee. These different compositions include API Classes A, E, and F cements containing additives such as retarders, bentonite, heavy weight materials and pozzolans. All compositions except mixtures of pozzolans and hydrated lime show from mild to severe degrees of strength loss over a temperature range from 230 to 320°F after setting. Pozzolan-lime compositions actually gain in strength with time at these high temperatures.

Other chemical and physical properties evaluated to observe their interrelationship with strength loss show very little correlation except in permeability. As retrogression in strength Increases, the permeability of set cement increases. X-ray diffraction patterns on the set products indicate the formation of certain compounds having little or no strength value in those cementing compositions where strength loss was more severe.

Introduction

As a result of the growing trend toward deep well completions, a study has been made on the properties of the various cementing slurries presently in use at elevated temperatures and pressure. The strength of these compositions is of prime importance in selecting the most suitable material for use at high temperatures, to determine WOC time and the proper time to perforate with a minimum of shattering. Of primary interest in this investigation was the strength behavior of various compositions currently in use, and the effect of additives on cement after long periods of curing under severe conditions.

Earlier investigators have pointed out that the strength of some cements will increase with increasing curing temperature to about 220 to 240°F, but at higher temperatures a loss in strength occurs at extended time intervals. Studies by the API Mid-Continent District Study Committee on Oil Well Cements outlined a testing procedure whereby field conditions of temperature and pressure could be simulated in the laboratory. It was observed that retarded cements undergo changes at elevated temperatures and some lose as much as 50 per cent of their early strength when cured at high temperatures. The scope of these tests was limited to curing periods of 1 to 28 days; additives were not covered in this study.
Determination of Wettability by Dye Adsorption
Authors: Holbrook O.C. , Bernard George G.
Published: February 2020

Published in Petroleum Transactions, AIME, Vol. 213, 1958, pages 261–264. Paper presented at 32nd Annual Fall Meeting of Society of Petroleum Engineers in Dallas, Tex., Oct. 6–9, 1957.

A method has been developed for determining the relative water wettability (fraction of the surface wet by water) of porous media. This method involves the adsorption of methylene blue dye from an aqueous solution onto the solid surfaces of rock contacted by the injected dye solution. Experiments on Berea sandstone cores have shown that water-wet cores adsorb a large amount of dye from solution. In oil-wet cores, however, the injected aqueous dye solution is prevented from contacting the adsorptive surfaces by a film of oil and virtually no dye is adsorbed.

This method was tested by experiments on mixtures of water-wet and oil-wet sand. Using the dye adsorption method, it was possible to determine quantitatively the fraction of water-wet and oil-wet sand in such mixtures.

The dye adsorption test is readily applied to determining the relative water wettability of fresh oilfield cores. The cores are not extracted before testing. Observed values of the wettability of field cores tested to date have varied from 100 to 6 percent water wet.
Miscible Fluid Displacement in Porous Media
Authors: Lacey James W. , Draper Arthur L. , Binder George G.
Published: February 2020

Published in Petroleum Transactions, AIME, Volume 213, 1958, pages 76–79.

An experimental investigation of miscible fluid displacement has been made in linear porous media under highly adverse mobility ratio conditions. Various refined oils were displaced at field rates by liquid propane in both horizontal and vertical models 9 to 36 ft in length.

In horizontal tests, mixed zones or transition zones form between the two liquids early in the displacements. Initially, the zones grow rapidly. In 2-in. diameter models, the mixed regions become nearly stable zones from 6- to 20-ft long. From then on these quasi-stable zones apparently grow only by molecular diffusion.

The lengths of the quasi-stable zones appear to be almost independent of the core material in which displacements are made and increase with increasing rates of injection and oil/solvent viscosity ratios. The lengths of the quasi-stable zones measured in 2-in. diameter models at viscosity ratios and injection rates anticipated in the field indicate that essentially piston-like displacements of oil by solvent would occur. However, the mixed zone lengths increase markedly as the model diameter increases.

In vertical displacements controlled by gravity drainage, only short transition zones form. The entire lengths of these zones can be accounted for by molecular diffusion. Therefore, in reservoirs having characteristics allowing a high degree of gravity drainage, nearly complete oil recovery should be attainable by miscible fluid displacement.

Introduction

The oil industry is faced with an ever increasing cost for finding new oil reservoirs. This, coupled with the fact that conventional methods of oil recovery usually leave from 1 to 3 bbl of oil in the ground for every barrel produced, has aroused considerable interest in developing more efficient methods. An integral part of the mechanism of many of these new methods of recovery is a miscible fluid displacement in which oil is displaced by a much less viscous material such as liquid propane. A number of investigators have explored the mechanics of miscible fluid displacement but in the experiments reported many of the important factors have been varied only over a limited range far removed from normal oilfield values.

This paper presents the results of an experimental study of oil displacement by liquid propane at field rates from linear, natural-sandstone models of various sizes. Both horizontal and vertical flow tests were made.
The Deterioration of Miscible Zones in Porous Media
Authors: Sievert John A. , Dew John N. , Conley Francis R.
Published: February 2020

Published in Petroleum Transactions, AIME, Volume 213, 1958, pages 228–235.

Recent literature shows that pronounced increases in oil recovery can result from the use of miscible systems in recovery operations. This literature also points out certain problems associated with maintaining miscibility, e.g., compositional changes resulting from alterations in pressure and temperature or from zone dilution. The purpose of the work described in this paper was to study miscible zones for possible use in waterflooding operations and examine the manner in which these zones break down. The fluid system selected for study was oil - tertiary-butyl alcohol - water, which, because of its narrow range of miscibility, is ideally suited for investigation in short, linear systems.

The laboratory-observed effects on oil recovery and zone stability of a number of variables are reported. Among the variables investigated were miscible zone size, viscosity ratio, length of travel, and interstitial water saturation.

Results obtained with this system show that interstitial water adversely affects recoveries because of premature phase break. Salinity of the water further aggravates this situation. This effect, although pronounced for this system, would probably occur in any fluid system containing an alcohol. As expected, viscosity ratio has a decided influence on recovery efficiency and zone stability. The results also show that use of a sufficient zone size, even though the system has poor phase characteristics, yields higher oil recoveries than are obtained from straight water floods. Length-of-travel studies showed a square root relationship between zone growth and path length for favorable viscosity ratios. No such clear-cut dependence was observed under unfavorable viscosity conditions.

Introduction

As new oil reserves have become increasingly more difficult and expensive to find and develop, the oil industry has devoted more and more time and money to finding more efficient methods for exploiting known reserves. The increasing number of water floods is one manifestation of this attempt to improve oil recoveries from existing fields. Since considerable quantities of oil are by-passed by the waterflood process, it is only a partial answer to the problem. The search continues.
Miscible Displacements of Reservoir Oil Using Flue Gas
Authors: Koch H.A. , Hutchinson C.A.
Published: February 2020

Published in Petroleum Transactions, AIME, Volume 213, 1958, pages 7–10.

Miscible phase displacement of oil from reservoirs has been emphasized in the past few years. The reason for this emphasis lies in the high oil recovery attainable by this process. Removal of capillary effects in the reservoir leads to recoveries approaching 100 per cent in the area contacted by the miscible phase.

The miscible slug process is one means of obtaining a miscible displacement. Here a band or slug of LPG is injected into the reservoir prior to gas injection. The idea is to maintain the band of LPG "wedged" between the gas and oil phases and thus achieve a miscible phase displacement. A second method for achieving miscibility is through the injection of a gas which is not miscible with the reservoir fluid but which develops a zone of miscibility in the reservoir through mass transfer with the reservoir oil. This mass transfer results in either an enrichment of the lean injected gas by intermediates from the oil or an enrichment of the oil by intermediates from a rich injection gas or one that has been enriched on the surface by LPG addition. We are interested here in discussing the process in which miscibility is developed at the displacement front by the evaporation of intermediates from the oil phase into the gas phase. This process "builds up" its own slug of miscible material at the displacement front and therefore does not require the injection of LPG to obtain miscibility. Each process has its own area of applicability. Generally, the high pressure gas process is applicable only with reservoir fluids which contain a high concentration of intermediates. If the high pressure gas process is technically feasible at pressures less than 4,500 psi, it is probably more desirable economically than the slug process. The slug process has broad applicability in the shallower reservoirs and with reservoir fluids which contain a relatively low concentration of LPG and natural gasoline constituents.

This paper deals with some new concepts of the high pressure gas injection process where it is proposed that flue gas can be substituted for hydrocarbon gas without sacrificing our goal of miscibility.
Fluid Dynamics During an Underground Combustion Process
Authors: Wilson L.A. , Wygal R.J. , Reed D.W. , Gergins R.L. , Henderson J.H.
Published: February 2020

Published in Petroleum Transactions, AIME, Volume 213, 1958, pages 146–154.

This paper presents a method of predicting the production history of an underground combustion recovery process. A rigorous solution of the thermodynamics and hydrodynamics involved is beyond the scope of this report. However, a practical scheme to appraise combustion recovery performance has been worked out. By prudent assumptions, regarding the attainment of steady-state conditions, a trial-and-error solution, which satisfies both material balance and three-phase relative permeability requirements has been evolved and tested.

As a combustion zone moves through a formation the interstitial water, the water of combustion and a portion of the oil will be vaporized. These vapors will move downstream to a cooler region of the formation where they will condense. Part of the remaining oil will be displaced by the imposed gas drive and what remains behind will be consumed as fuel. The fluids will distribute themselves downstream in a manner which will satisfy the three-phase relative permeability characteristics of the formation. Three distinct zones will exist ahead of the combustion zone:a zone termed a water bank which contains three mobile phases, oil, water and gas;a region containing two mobile phases, oil and gas, called the oil bank; anda zone having the fluid saturation distribution which existed prior to combustion.

The mobile water will impose a water flood on the oil in the region containing three flowing phases. The process can be visualized as a simultaneous water flood and combustion-supported gas drive. It is possible to estimate the saturation distributions in the water bank and oil bank as well as the production history for any combustion temperature if the porosity, three-phase relative permeability characteristics, oil viscosity and initial saturations are known. This has been done for injection pressures ranging from 1 to 100 atm, oil viscosities of 10 to 1,000 cp and porosities from 20 to 40 per cent. Several of these calculations have been checked in the laboratory, with the result indicating rather good agreement between the predicted and observed production histories.

The analytical and experimental techniques are described and the comparison of predicted and observed performance presented.
Extensions of the Muskat Depletion Performance Equation
Authors: West R.D.
Published: February 2020

Published in Petroleum Transactions, AIME, Volume 213, 1958, pages 285–291.

Muskat's depletion performance equation is here derived considering the expansion behavior of the reservoir hydrocarbon system and a simple fractional-flow equation. This method of derivation leads logically to the two extensions that follow. The first of these is concerned with gravity segregation in a depletion-drive reservoir. The second is concerned with including an empirically determined term for water influx in the performance equation. The more general equation for gravity segregation when there is a primary gas cap and empirically-determined water influx is stated for completeness. These equations have been found useful in reservoir performance calculations in Eastern Venezuela.

A discussion on the methods of solving these equations follows, and considers firstly the effect of taking finite intervals in the numerical integration, and secondly, methods of incorporating the time functions involved in segregation in with the expansion behavior. The paper concludes with a brief general discussion on further extensions to the depletion performance equation.

Introduction

The two fundamental sources of energy by which oil is produced from a reservoir result from pressure depletion inside the boundaries of the reservoir and fluid encroachment across the boundaries of the reservoir. The wells in either case form low pressure outlets through which oil and gas may be produced by the expansive force of the reservoir fluids and associated encroaching fluids.

When the reservoir pressure is higher than the bubble-point pressure of the oil, so that there is no free gas in the reservoir, these expansive forces are the only ones available for the production of oil. However, when the reservoir pressure is less than the bubble-point pressure of the oil, free gas is vaporized as the pressure falls. With both oil and free-gas phases present, the additional forces of gravity and capillarity may operate on the gas-oil system, as they have previously operated on the oil-interstitial water system. Gravity tends to segregate the free gas from the oil due to their density difference. Capillarity opposes and eventually balances gravity as the more extreme free gas and oil saturations are reached, preventing the independent movement of free gas until it is above a certain saturation, and the independent movement of oil when it is below a certain saturation.