bluuebunny/crossref_metadata_2025_split huggingface dataset:
A Model for the Mechanism of Oil Recovery from the Porous Matrix Due to Water Invasion in Fractured Reservoirs
Authors: Aronofsky J.S. , Masse L. , Natanson S.G. 
Published: February 2020

Published in Petroleum Transactions, AIME, Volume 213, 1958, pages 17–19.

Introduction
The first step in a quantitative analysis of the mechanism of oil displacement by water in a fractured reservoir is usually conceded to be the solution of the differential equation describing the saturation distribution of two immiscible fluids flowing in a porous medium, where the capillary pressure is taken into account. In such a system the production mechanism may consist of displacement of oil both by the flow of water due to natural or artificially imposed pressure gradients and by imbibition, which implies a flow of water not due to external pressure gradients. Owing to the presence of the two oil displacement mechanisms, the mathematical model given by the differential equation intended to describe the system may not properly represent the behavior of the physical system. In fact, in the reservoir the rate of water advance may be very slow, and in the case of a fractured reservoir with a great number of large fractures, the pressure difference determining the flow of water through the matrix may be much less than 1 lb/psi over lengths of a few feet. In such a case, imbibition (the exchange between oil in the matrix and water in the fractures resulting from capillary forces) may become, with time, a significant element of the production mechanism.
It occurred to the authors, however, that without going into a physical analysis of the process of production, it might be possible by means of simple abstract reasoning to throw some light on the variation of recovery with time under conditions occurring in a highly fractured oil reservoir with rising water table.
The object of this paper is to present both the reasoning and its application to a reservoir of the highly fractured type. Specifically, the analysis given here was undertaken to try to explain the increase of recovery (as defined later) with time as observed in this reservoir, without having to assume unlikely variations in the reservoir parameters with depth. This attempt has been successful as will become clear upon comparison of the computed recoveries with the actual field data.
The Use of High-Speed Computers for Predicting Flood-Out Patterns
Authors: McCarty D.G. , Barfield E.C. 
Published: February 2020

Published in Petroleum Transactions, AIME, Volume 213, 1958, pages 139–145.

Abstract
Two-dimensional analyses offer considerable promise in providing the basic information required to effect in ore precise control of petroleum reservoir performance. This paper describes a method for conducting some engineering analyses of this type using a high-speed digital computer. The general approach is to (1) develop a representative numerical model of the reservoir and(2)employ a suitable numerical technique to solve the basic equation of flow and to develop the required engineering information for the particular case represented by the model.
This technique has been used to calculate pattern performance in connection with several field projects involving water injection into oil reservoirs. This type of analysis involves sequentially(1)calculating the pressure distribution in the reservoir and (2)tracking the progress of the interface between the displaced and displacing fluids in a step-wise manner to provide a depletion history of the operation.
The particular analysis presented in this discussion is subject to the restriction that the mobility of the displaced and displacing fluids be equal and assumes that the fluids are incompressible and that gravity and capillary pressure do not affect the shape of the flood pattern. Complete two-dimensional flexibility is maintained with regard to definition of reservoir rock and fluid characteristics, placement of physical restraints and boundary conditions, investigation of flow characteristics in the reservoir, and movement of the displaced and displacing fluid interface.
The results of these studies indicate that the high-speed digital computer is well suited for conducting reservoir performance studies in two-space dimensions and that dependable numerical techniques are available for making such analyses.

Introduction
One of the problems facing petroleum engineers is that of providing more precise engineering control over reservoir operations at all stages during the depletion cycle. The most direct approach to this problem is to simulate the reservoir with some type of physical or mathematical model and use the information developed from the behavior of the prototype to predict the performance of the actual reservoir. This principle is, of course, not new, and a variety of simulation techniques have been developed to provide information on the behavior of oil and gas reservoirs.
Mechanics of Differential Pressure Sticking of Drill Collars
Authors: Outmans H.D. 
Published: February 2020

Published in Petroleum Transactions, AIME, Vol. 213, 1958, pages 265–274.Paper presented at Annual Fall Meeting of Southern California Petroleum Section in Los Angeles, Calif., Oct. 17–18, 1957.

Abstract
Drilling progress is often delayed by sticking of the drill string. The development of preventive and remedial methods has been hampered by incomplete understanding of the sticking mechanism. A recent laboratory investigation has indicated that one type of sticking may be attributed to the difference in pressure between the bore-hole and formation. This paper shows, by means of soil mechanics, that the primary cause for differential pressure sticking is cessation of pipe movement, whereas differential pressure and standing time determine the severity of the sticking. The analysis stresses the importance of using low-weight muds with low solids content and low water loss to alleviate differential pressure sticking and describes why packed hole drilling, long strings of drill collars, and a large deviation from the vertical are conducive to sticking. Finally, preventive and remedial methods are evaluated, and a theory is presented on the release of stuck pipe by spotting oil.

Introduction
Since drilling with long strings of oversize drill collars has become standard practice in many areas, the incidence and severity of the stuck pipe problem has increased. It has been noticed that in the majority of these cases the sticking could not possibly be attributed to key seating or caving of shales. It appeared that, due to the differential pressure between the mud column and the formation fluid, the collars were pressed into the wall and so became "wall stuck". Points to note about differential pressure sticking are:sticking is restricted to the drill collars,the collars become stuck opposite a permeable formation,the sticking occurs after an interruption of pipe movement,circulation, if interrupted, can be restarted after the sticking is noticed, andno large amounts of cuttings are circulated out after restarting circulation.
Some Thermal Characteristics of Porous Rocks
Authors: Somerton Wilbur H. 
Published: February 2020

Published in Petroleum Transactions, AIME, Volume 213, 1958, pages 375–378.

Abstract
Results of experimental measurements of heat capacities and thermal conductivities of some typical porous rocks are presented. Measured heat capacities agree closely with values calculated from known chemical compositions of the rocks. On the basis of this agreement, heat capacities of fluid-saturated rocks were calculated. Thermal conductivities of the rock samples were measured under various conditions of fluid saturation. From these data thermal diffusivities were calculated. A significant variation of thermal diffusivity with temperature is indicated.

Introduction
Knowledge of the thermal characteristics of fluid-bearing porous rocks has become increasingly important with the development of thermal oil-recovery processes. Reliable thermal data for petroleum reservoir rocks are not available and approximate values are generally assumed for reservoir calculations. The effects of temperature, pressure and fluid saturation on thermal properties of porous rocks have not been carefully studied.
The purpose of the present work was to measure and report the thermal characteristics of some typical porous rocks. A group of eight sedimentary rock samples, including limestone, shale, sandstone and siltstone, was selected for the study. Properties reported include heat capacities, thermal conductivities and thermal diffusivities. The effect of fluid saturation on these properties was also considered.
Determinations of thermal properties require precise measurements which are time consuming and difficult to reduce to a routine basis. Methods have not been developed for measurement of thermal properties under conditions of pressure, temperature, and fluid saturation, which may be encountered in thermal recovery processes. As one approach to these problems, some preliminary work on methods of estimating thermal properties from other more readily measurable characteristics of the rock-fluid system is reported.
Effect of Flow Rate on Paraffin Accumulation in Plastic, Steel, and Coated Pipe
Authors: Jessen F.W. , Howell James N. 
Published: February 2020

Published in Petroleum Transactions, AIME, Volume 213, 1958, pages 80–84.

Introduction
The accumulation of paraffin deposits in tubular goods has been recognized as a major production problem since the inception of the petroleum industry. This problem is not limited to any particular geographical area nor is it limited to a specific type of crude oil. Generally speaking, "paraffin" deposition pertains to the deposition of any predominantly organic material in flow lines, and possibly even at the sand face, which would hamper the production of oil. In some fields, a continuous effort is required to remove deposits of paraffin and in order to accomplish this, many unique methods have been devised. The best solution to this problem, however, is to prevent the formation of such deposits. One method which has been tried in a number of fields is the use of plastic pipe.
The purpose of this investigation is to compare the relative effectiveness of several plastic materials to aid in the reduction or prevention of paraffin accumulations in surface flow lines.

Composition of Paraffin Deposits
By definition, paraffin deposits are those materials which are insoluble in crude oil at the prevailing producing conditions of temperature and pressure. Such deposits usually consist of small particles of petroleum wax intermixed with resins, asphaltic material, and crude oil. They may also contain a variety of foreign materials such as sand, silt, water, various metal oxides, sulfates and carbonates of iron, barium, and calcium.
The petroleum waxes deposited in flow strings usually consist of both a "hard" and a "soft" wax fraction. These waxes are largely aliphatic hydrocarbons with smaller amounts of aromatic and naphthenic compounds. Nathan has classified the hard and soft wax fractions. The aliphatic hydrocarbons present are those of high molecular weight with high melting points. Reistle pointed out that these high molecular weight compounds first separate from the oil due to a sharp decrease in solubility as the melting point increases.
The identification of the resins and asphaltic materials rests, at present, on an arbitrary solubility procedure. Under certain conditions, materials which are insoluble in pentane (ASTM D–893) are defined as resins and asphalts. Subgrouping of these materials is made on decreasing solubility in benzene and carbon disulfide.
Shock found some correlation between the solvent response and the pentane insoluble content of paraffins; higher pentane insoluble fractions are less soluble in any of the commonly used commercial solvents.
Application of Decline Curves to Gravity-Drainage Reservoirs in the Stripper Stage
Authors: Lefkovits H.C. , Matthews C.S. 
Published: February 2020

Published in Petroleum Transactions, AIME, Volume 213, 1958, pages 275–280.

Abstract
In a recent publication it was shown that wells with a free surface in a homogeneous gravity-drainage reservoir have a hyperbolic decline with index n = 2, q/qi = 1/(1 + ?t)2. This paper reports efforts to extend this theory to practical field cases.
As a first step in making the extension, a large number of lease production curves from gravity-drainage fields in the stripper stage were fitted with the general hyperbolic decline equation, q/qi = 1/(1 + ?t)n, ? and n in each case being determined by statistical methods. It was found that this equation is reliable for decline curve extrapolation for periods up to at least 25 years.
The results obtained were disturbing in the sense that values for the index, n, were often smaller than one, which fact leads to the prediction that a well would produce an infinite amount of oil in infinite time. A theoretical investigation based on the results of the previous paper provides a suitable explanation for these low values of n. It suggests that these are obtained if production occurs from two or more layers of different permeability and thickness or two layers having different skin effects. It is predicted that as the more permeable layers are exhausted, the index of decline, n, will rise from a value smaller than 2, to n = 2.
A practical method is given for fitting the general hyperbolic decline Eq. 6 to production decline data. When this method is used, the index of decline observed in gravity-drainage reservoirs in the stripper stage when using only data over early years of decline usually agrees quite closely with that determined using data over 25 years or more. This indicates that the hyperbolic decline equation is reliable for predicting behavior of such reservoirs. A method is also suggested for taking into account any changes in the value of the index of decline, n, which may be expected during the life of a well or lease.
The Effect of Partial Penetration on Pressure Build-Up in Oil Wells
Authors: Nisle Robert G. 
Published: February 2020

Published in Petroleum Transactions, AIME, Volume 213, 1958, pages 85–90.

Abstract
The classic theory of pressure build-up in shut-in oil wells as developed by Horner and van Everdingen is based on two-dimensional radial symmetry in the well-reservoir system. Such symmetry does not exist in the case of a well which partially penetrates the producing formation. As a result of this lack of symmetry the use of the classic theory in such cases become questionable.
In this paper the mathematical theory has been extended to include the case of partially penetrating wells. Numerical solutions illustrating the application of the equations are presented. The effect of partial penetration on pressure build-up is shown by a comparison of synthetic pressure build-up curves derived from the numerical solution of the equation for partially penetrating wells for various degrees of penetration. It is shown that partial penetration is detectable from the characteristic shape of the pressure build-up curve and that formation productivity may be calculated from the pressure build-up data in a manner identical to that described by the classic theory.

Introduction
The use of pressure build-up data on shut-in oil wells is a well-established technique for the measurement of reservoir productivity. The work of Horner and van Everdingen is well known. Since the publication of their pioneering work, others have elaborated and extended the technique. These authors have dealt exclusively with the case of wells that completely penetrate the producing formation. Two-dimensional radial symmetry is achieved, thereby, and the problem is greatly simplified.
This ideal situation is seldom encountered in practice. But, in spite of this, the technique is often employed anyway. The question, therefore, arises: how much confidence can be placed in the results of such calculations when the data are taken on wells that only partially penetrate the producing formation? It is the purpose of this work to answer this question. Only the single-phase fluid case will be considered.
Producing Wells on Casing Flow - An Analysis of Flowing Pressure Gradients
Authors: Baxendell P.B. 
Published: February 2020

Published in Petroleum Transactions, AIME, Volume 213, 1958, pages 202–206.

Abstract
The Cretaceous limestone wells of the Mara/Maracaibo Dist. of Venezuela are extremely prolific producers. To maintain production on cessation of natural flow, large scale gas-lift operations were commenced involving high production rates on casing flow. For the design of these gas-lift installations it was essential to have some knowledge of the pressure gradients involved in casing flow, so that the required injection pressures optimum gas injection rates, etc., could be forecast.
This paper presents a method of calculating these annular pressure gradients. Basically the method makes use of an energy balance equation coupled with an empirical energy lab factor derived from field data. The calculations have been put in a form suitable for "punch card-type" calculating machines.
A set of gradient curves for Mara/Maracaibo conditions covering flow rates up to 12,000 B/D, and GOR's of 500 to 2,000 cu ft/bbl is presented. From these (curves the flowing BHP can be predicted from surface data and the vertical flow performance under varying conditions of gas injection can be estimated.
The method has been applied to La Paz and Mara gas-lift operations for over three years and has given consistently accurate results.

Introduction
The Cretaceous limestone fields of the Mara/Maracaibo area in Venezuela are characterized by the presence Of widely distributed fissure systems. Under these conditions individual wells frequently have extremely high potentials and such wells are generally flowed on the casing-tubing annulus in order to reduce the pressure loss in vertical flow. To maintain production on cessation of natural flow, an extensive gas-lift system was planned.
As a first approach to this gas-lift design problem, an attempt was made to construct a set of empirical flowing gradient curves from the available subsurface pressure data. Such a method has been used successfully for tubing-flow conditions in California by Gilbert. Unfortunately, the empirical construction of casing-flow gradient curves presents additional difficulties, as pressure bombs cannot be run in the casing-tubing annulus against high rates of flow. Thus, the full flowing gradients cannot be defined by actual measurement and the best that can be done is to obtain spot pressures at the tubing shoe. Under these conditions a vast accumulation of BHP data is required to construct a set of gradients.
O POCZĄTKACH SPÓŁKI AKCYJNEJ
Authors: Dąbrowska Justyna 
Published: February 2020

Celem artykułu jest prezentacja i uzasadnienie poglądu o początkach spółki akcyjnej. Za pierwsze spółki akcyjne typowo uznaje się angielskie i holenderskie wielkie handlowe. Zalążków spółki udziałowej należy doszukiwać się jednak znacznie wcześniej, bowiem już od XII w. Spółki w różnych częściach Europy opracowały i rozwinęły w praktyce koncepcję korporacji. Średniowieczne spółki uzyskiwały samodzielność prawną, a uczestnictwo w ich strukturach opierało się na zbywalnym udziale. Kuxe, uchaux i sortes to w pewnym sensie odpowiedniki dzisiejszych akcji. Choć nie wykształcono jeszcze w owym czasie koncepcji osobowości prawnej ani kapitału zakładowego, zaś wspólnicy generalnie odpowiadali za zobowiązania organizacji, to spółki te, w odróżnieniu od spółek handlowych innego typu, były zawiązywane w stałym celu gospodarczym, a zmiany składu wspólników nie miały wpływu na ich funkcjonowanie. Odmiennie niż pierwsze wielkie kompanie handlowe, które powstawały w oparciu o akt władzy monarszej, spółki średniowieczne wdrażały sposób reprezentacji i zarządzania oparty na umowie wspólników i rządach większości.
Jednoczesne i w pewnym stopniu niezależne od siebie wykształcenie się i ewolucja spółek młyńskich (pariages ds moulins), gilda mercatoria, spółek kopalnianych, włoskich montes, towarzystw żeglugowych (Rhedereien), gwarectw (Gewerkschafen) i innych podobnych form dowodzi, że powstanie spółki akcyjnej jest bezpośrednio powiązane z rozwojem cywilizacyjnym i przemianami społeczno-gospodarczymi.
DYLEMATY WDROŻENIA MECHANIZMU ‘KüHNE & HEITZ’ DO KODEKSU POSTęPOWANIA ADMINISTRACYJNEGO
Authors: Łuczak Konrad 
Published: February 2020

W celu zapewnienia wpływu swoich wyroków prejudycjalnych na ostateczne decyzje administracyjne krajowych organów administracyjnych, które wszakże z powodzeniem przeszły sądową kontrolę, Trybunał Sprawiedliwości Unii Europejskiej wprowadził mechanizm Kühne & Heitz. Stosowanie tego mechanizmu zostało powierzone organom administracyjnym po to, aby doprowadzić do zmiany decyzji ostatecznej w kierunku wyznaczonym przez wykładnię prawa UE ustaloną w późniejszym wyroku Trybunału, wydanym w odrębnej sprawie. Niniejszy artykuł stara się odpowiedzieć na pytanie, czy w kodeksie postępowania administracyjnego obowiązują regulacje procesowe, które można uznać za efektywne sposoby realizacji mechanizmu Kühne & Heitz oraz analizuje wyłaniające się na tym tle podstawowe problemy.
Szczegółowa analiza przedstawionego zagadnienia obejmuje: określenie celów mechanizmu Kühne & Heitz, zbadanie relacji zachodzących pomiędzy tym mechanizmem a zasadami skuteczności i równoważności, charakterystykę i krytyczne omówienie przesłanek jego zastosowania, ocenę trzech instytucji procesowych uregulowanych w kodeksie postępowania administracyjnego pod kątem ich przydatności dla funkcjonowania tego mechanizmu (wznowienie postępowania, stwierdzenie nieważności decyzji i uchylenie lub zmianę decyzji w trybie art. 154 i art. 155 k.p.a.), a także rozważenie projektu nowelizacji kodeksu, w którym między innymi zaproponowano wprowadzenie nowej podstawy wznowienia postępowania, jednoznacznie odnoszącej się do sytuacji niezgodności decyzji ostatecznej z późniejszym wyrokiem Trybunału.
Summary of Guidelines for Exercise in Pregnancy–are they Comprehensive Enough for Designing the Contents of a Prenatal Exercise Program?
Authors: Szumilewicz Anna , Worska Aneta , Rajkowska Natalia , Santos-Rocha Rita 
Published: February 2020

Background:
Regular physical activity during pregnancy has a positive effect on the psychophysical condition of the pregnant woman, pregnancy and fetal development, parturition and the postpartum period. However, its level in pregnant women is insufficient in most countries. For an exercise program to be effective it must take into account four training components: intensity, frequency, duration and its content - through a proper selection of the type of exercises and their technique. In this work we aimed to answer the question what information on the contents of prenatal exercises is provided in the current guidelines for exercise during pregnancy in different countries.

Methods and Results:
We have analyzed 11 documents, that were the official position of national obstetrics, gynecology, or sports medicine institutions from 7 countries. The guidelines provide little information on the contents of prenatal exercise and on the adaptation of sports activities to pregnancy.

Conclusions:
The guidelines for exercise in pregnancy should be updated based on high-quality research and in collaboration with practitioners in the field of prenatal physical activity, which could increase the chances of their implementation. Trustworthy and comprehensive guidelines created on the basis of international and interdisciplinary initiatives should be disseminated among all interested in prenatal physical activity: pregnant women and their families, obstetrics care providers and exercise professionals to enable them an effective cooperation and to globally promote exercise in pregnancy.