bluuebunny/crossref_metadata_2025_split huggingface dataset:
The Area Analysis of Resources
Authors: Webster Barbara , Stewart John 
Published: December 2007

There has been increasing interest in this country in variations in expenditures between different local authorities among political scientists, social administrators, economists, and others, as there has been elsewhere. All these and other studies are distinguished by their concentration upon variations in expenditure between local authorities. The local authority has been treated as the basic unit. There has been no parallel development in studies of the degree of variation of expenditure within the area of the local authority.
Some of the factors considered as determinants of variations in expenditure in the inter-authority studies will also vary within the area of the local authority. Social conditions, for example, may differ markedly over an urban area. The question therefore arises as to whether any variation in expenditure by the local authority is, or should be, related to such social differentiation. An intra-authority analysis of resources is supported by research aimed simply at describing or explaining social patterns within cities. Work has been undertaken to identify areas of social malaise or areas of multiple deprivation within urban areas. A comparison of the areal distribution of resources with that of social malaise or deprivation may provide guidance for future allocation decisions.
Integral equations for an inverse boundary value problem for the two-dimensional Stokes equations
Authors: Alves C. J. S. , Kress R. , Silvestre A. L. 
Published: December 2007

Abstract
The problem to determine the location and shape of a perfect conductor within a conducting homogeneous host medium from measured current and voltages on the accessible exterior boundary of the host medium can be modelled by an inverse Dirichlet boundary value problem for the Laplace equation. For this, recently Kress and Rundell suggested a novel inverse algorithm based on nonlinear integral equations arising from the reciprocity gap principle. The present paper extends this approach to the problem to recover the location and shape of a rigid body immersed in a fluid from the measured velocity and traction at the exterior boundary of the fluid, that is, to an inverse boundary value problem for the Stokes equation. The mathematical foundation of this extension is provided and numerical examples illustrate the feasibility of the method.
Comparing the Rotary With Potential Drilling Methods
Authors: Simon R. 
Published: December 2007

Abstract
Most new methods of oil well drilling achieve increased rates of penetration essentially by increasing the mechanical power input to the rock over the maximum practical power level obtainable by conventional rotary drilling. However, whether this would decrease the drilling cost per foot of hole depends upon other factors as well, such as the cost of operation per unit time, well depth and the distribution of rocks of various drillabilities at the well site.

Introduction
Rotary drilling, introduced about 1900, is today the most widely used method of drilling oil wells in this country. The past 50 years have seen great strides in improved equipment and techniques for rotary drilling. However, the limitations of rotary drilling have long been recognized and there have been many attempts to develop new drilling methods to supplement or to supplant rotary drilling. The potentialities of some of these new drilling methods for decreasing the cost of drilling oil wells are discussed herein.

Drilling Rate and Mechanical Power
One significant result of a study of the fundamentals of rock drilling made at Battelle is that the fracture of brittle rock from the bottom of a hole by repetitive, indexed mechanical loading involves the expenditure of a certain amount of mechanical energy per unit volume of rock fractured out. Therefore, the rate of penetration of any mechanical drilling machine would be essentially directly proportional to the mechanical power developed in the rock per unit area of hole and inversely proportional to the drilling strength, which is the energy required to fracture off a unit volume of rock.

Limitations of Rotary Drilling
The mechanical power output to the rock for conventional rotary drilling is proportional to the torque required to turn the bit at the bottom of the hole and to the rate of rotation of the bit. The torque reaction to rotation associated with a given amount of static weight loading on the bit is less for the rocks of greater drilling strength. Since less mechanical power is developed in rocks of greater strength, the rate of penetration decreases more rapidly than in inverse proportion to the drilling strength. There is, consequently, a wide range in the drilling rates obtained by rotary drilling, perhaps about 50 to 1 from the weakest to the strongest rock of interest in oil well drilling.
Early Performance Review of a Successful Pressure Maintenance Project in a Deep Louisiana Reservoir
Authors: Greenwalt Don R. 
Published: December 2007

Abstract
The Broussard oil sand unit, operated by Tidewater Oil Co, is located in the Erath field, Vermilion Parish, La. The unit was formed as a reservoir-wide pressure maintenance project utilizing salt water injection below 12,500 ft. Formation of a reservoir-wide unit was accomplished and pressure maintenance operations were initiated in April, 1961. Actual performance of the project during the more than three years of operation has been very close to predicted performance. Reservoir productive capacity is in excess of the unit allowable of 1,764 BOPD. Performance of the project to date indicates that ultimate recovery from the reservoir will reach or exceed the predicted value of 7.4 million STB oil.
Introduction
The Broussard oil sand unit is located in the Erath field of Vermilion Parish, La. (Fig. 1). The Broussard sand was proven productive with the completion of the Tidewater Oil Co. H. H. Broussard Well No. 1 (B-4) in Jan., 1957. Development of the reservoir was completed in 1959, with 13 oil completions producing 1,538 B/D from an average depth of 12,440 ft sub-sea. In addition to the 13 producing wells, four dry holes were drilled before the reservoir limits were completely defined. Pressure-production performance of the reservoir indicated the reservoir energy mechanism is solution-gas drive with a weak water drive. Reservoir engineering studies indicated that the natural reservoir energy would recover only 31 per cent of the estimated 12.8 million STB oil initially in place. Secondary recovery feasibility studies indicated that pressure maintenance by water injection could greatly increase the ultimate recovery from the reservoir. The reservoir was unitized on a 100 per cent acre-foot basis, effective April 1, 1961. On that date, Tidewater Oil Co. became operator of the first reservoir-wide unit to be formed under Louisiana Department of Conservation Act 441, Act 441 provides for forced pooling of a reservoir to prevent mineral waste if 75 per cent of both the royalty interest owners and the working interest owners approve the unitization.
Sixteen days after unitization was effective, pressure maintenance operations were initiated by down-dip water injection in one well. Additional development has expanded the injection pattern to five wells, all of which are injecting water below a depth of 12,500 ft sub-sea. The pressure maintenance project has been in operation for over three years. During this time over 1.9 million bbl of oil have been produced and 3.1 million bbl of water have been injected. This paper is a review of the operation of the project during the three years since unitization with a comparison of predicted pressure maintenance performance vs the actual performance.
Geological and Reservoir Data
The Broussard oil sand unit is one of Louisiana's and the petroleum industry's deepest water injection projects in an oil reservoir. The reservoir is located on a monocline from a depth range of 12,200 to 12,600 ft sub-sea (Fig. 2).
JPT
P. 1357^
The Effect of Temperature on Gelation Time for Polyacrylamide/Chromium (III) Systems
Authors: Jordan Deborah S. , Green Don W. , Terry Ronald E. , Willhite G. Paul 
Published: December 2007

Abstract
Gelled polymers are being applied to modify the movement of injected fluids in the vicinity of injection and production wells in secondary and enhanced oil-recovery projects. One approach to gelation is to form a bulk gel in situ by injecting a slug of a Polyacrylamide polymer solution containing chromium(VI) followed by a polymer slug containing a reducing agent such as sodium bisulfite. Upon mixing, CR(VI) is reduced to Cr(III), and in the subsequent reaction a gel is formed. The gelation time controls the volume of fluid that can be injected in the treatment and thus is an important variable in the process. Gelation time is known to be a function of the concentration of the reactants (chromium ion, reducing agent, and polymer) as well as the polymer type, and some data relating these variables to gelation time have been reported. Another variable affecting the reaction rate is temperature, but no data relating gelation time and temperature have been published.
The purposes of the work described in this paper were to obtain experimental data on the effect of temperature on gelation time for typical polyacrylamide/Cr(III) gel systems over the range of temperatures commonly encountered in reservoirs and to develop a method of correlating the data. Gelation times were measured for five different polymers, including polymers with various degrees of hydrolysis and polymers with nonionic, anionic, and cationic character. The temperature range was 25 to 80°C. Polymer, metal ion, and redox system concentrations and salinity also were varied. It was determined that, for a given polymer-reducing agent system at a specified concentration, the gelation time decreases as temperature is increased. The data were correlated in a manner analogous to the Arrhenius method of correlating chemical reaction rate data. That is, plots of the logarithm of gelation time vs. the reciprocal of the absolute reaction temperature were linear over the temperature range studied. By use of a simple nth-order reaction rate model, the slope of the Arrhenius-type plot was related to activation energy. These activation energies were found to vary only slightly for the polymer systems and concentrations investigated.
The results have direct application in the design of gel treatments for injection or production wells. The correlation method provides a way of predicting the effect of temperature on the time required for a given system to gel. It is recognized that in field applications factors beyond the scope of data taken in this paper may affect the gelation process.
Changes in Earth Stresses Around a Wellbore Caused by Radially Symmetrical Pressure and Temperature Gradients
Authors: Perkins T. K. , Gonzalez J. A. 
Published: December 2007

Abstract
Pressure and temperature gradients are created around wellbores during waterflooding or when fluids are injected in connection with any other secondary or tertiary recovery process. These gradients result in changes in earth stresses, which in turn cause hydraulic fracturing pressures to change.
In this paper, analytical solutions have been used to determine the stresses resulting from radially symmetrical temperature and pressure changes around a wellbore. These stresses are required to predict the change in fracture extension pressure that is caused by the injection process. Exact, closed-form solutions are given for the stresses. These have been evaluated with a computer, and more convenient empirical formulas have been fitted to the calculated results. Solutions for discrete cylindrical or disk-shaped regions of changed temperature and pressure are shown. Also, the solutions can be adapted to annular elements of finite thickness that are convenient for incorporation to an r-z-type computer program. Such a program could then be used to compute the stresses resulting from temperature and pressure fields that vary gradually in the radial direction.
This paper gives examples to illustrate the effect of injecting a large volume of liquid that is cooler than the insitu reservoir, as is common when waterflooding. The cooling can have a large effect on lateral earth stresses, and for some conditions vertical hydraulic fracturing pressures can be significantly reduced.
Pembina Pilot Water Flood Proving Successful
Authors: Justen John J. , Hoenmans Paul J. 
Published: December 2007

Introduction
The Pembina field, located in the Province of Alberta in Western Canada as shown above, is the largest oil field in Canada and one of the largest in the North American continent. The productive area, as defined by the Alberta Oil and Gas Conservation Board, is approximately 300,000 acres. Over 2,000 wells have been drilled. The original oil in place is estimated to be 4 billion STB. Although less than five years old, the pool to date has produced nearly 100 million bbl of oil. The current production rate is 100,000 B/D. The graphic reservoir history is presented in Fig. 1.
The reservoir is a stratigraphic trap producing from the Cardium formation. Neither bottom water nor free gas has been found. This sandstone has an average net thickness of 19.0 ft, an average porosity of 14.2 per cent and an average interstitial water saturation of 10.5 per cent. The average permeability varies from 34 md in the main part of the pool to 9 md in the western part. Nearly every well has been fractured to obtain production in commercial quantities.
The crude oil was initially undersaturated with a major portion having a solubility in the order of 500 scf/bbl and a bubble point in the order of 1,700 psig. The average gravity is 37.1°API.
Increasing gas-oil ratios, decreasing productivities, and rapid pressure decline have established the producing mechanism to be the expansion of the undersaturated crude oil followed by solution gas drive. The natural depletion recovery has been estimated at 12.5 per cent.
Pressure maintenance studies of various areas in Pembina have indicated that the recovery can be increased 2½ times by water flooding. Beginning in 1956, waterflooding operations were commenced by several operators. Most of these operations were pilots. One such operation was commenced by Mobil Oil in Canada, Ltd. which has more than 50,000 acres and over 550 wells.
Real Gas Pseudopressures For CO2 Reservoirs
Authors: Tiab Djebbar 
Published: December 2007

Abstract
This paper presents a new method for correlating real gas pseudopressure values of gas reservoirs containing large amounts of CO2. Special attention is devoted to gas reservoirs in Colorado, New Mexico, and Utah. These reservoirs have 95 to 100% CO2 concentrations. The effects of CO2 on the skin factor also are analyzed.
The main results of this study are that (1) the effects of CO2 on the conventional pressure analysis techniques are severe at higher mole fractions and at pseudoreduced pressures greater than one, (2) if real gas pseudopressure data are not properly corrected, the reservoir permeability calculated from pressure buildup and drawdown tests will be considerably less than the actual value, and (3) the proposed technique is simple, quick, and accurate enough to calculate pseudopressure values. This method is also useful in gas reservoirs with 0 to 100% CO2 concentrations.
CO2 affects the skin zone both physically and chemically, in most cases favorably. The total skin factor is slightly dependent on time for very short transient flows. However, it ultimately will become constant as the CO2 gas sweeps the entire skin zone.
Pressure Transient Analysis of Two-Phase Flow Problems
Authors: Chu Wei-Chun , Reynolds A. C. , Raghavan Rajagopal 
Published: December 2007

SummaryThis paper considers the analysis of pressure drawdown and buildup data for two-phase flow problems. Of primary concern is the analysis of data influenced by saturation gradients that exist within the reservoir. Wellbore storage effects are assumed to be negligible. The pressure data considered are obtained from a two-dimensional (2D) numerical coning model for an oil/water system. We consider constant-rate production followed by a buildup period and assume that the top, bottom, and outer boundaries of the reservoir are sealed.First, we consider the case where the producing interval is equal to the total formation thickness. Second, we discuss the effect of partial penetration.In both cases, we show that average pressure can be estimated by the Matthews-Brons-Hazebroek method and consider the computation of the skin factor. We also show that a reservoir limit test can estimate reservoir PV only if the total mobility adjacent to the wellbore does not vary with time.
Recovery of Bitumen From Tar Sand Deposits With the Radio Frequency Process
Authors: Sresty Guggilam C. , Dev Harsh , Snow Richard H. , Bridges Jack E. 
Published: December 2007

Summary
The IIT Research Institute (IITRI) radio frequency (RF) process for tar sands consists of two steps: (1) the deposit is volumetrically heated with RF energy to lower the viscosity of the bitumen, and (2) the bitumen is produced by one of several petroleum recovery methods. The RF heating step is accomplished by inserting tubular electrodes into boreholes and by energizing them with an RF power source. The electrode pattern is designed so that the deposit between the electrodes is uniformly heated with a minimum energy loss. The operating frequency is selected on the basis of the electromagnetic characteristics of the deposit. The recovery techniques that we investigated include replacing the heated bitumen with sodium silicate solutions, by gravity drainage, and by autogenously developed steam and hydrocarbon gases.
Two small-scale field experiments were conducted in the Asphalt Ridge tar sand deposit near Vernal, UT. About 25 m3 [33 cu yd] of the deposit was heated with RF energy, and about 35% of the total in-place bitumen was recovered during the 3-week test period.
In-Situ Leaching of South Texas Uranium Ores—Part 1: Laboratory Studies of Ore Composition and Leaching Performance
Authors: Paul J. M. , Tsui T. F. , Edwards J. T. , Holmes B. G. , Venuto P. B. 
Published: December 2007

Abstract
This paper presents data on mineralogy and laboratory chemical-leaching tests for ore samples from several areas of the south Texas tertiary Catahoula formation. Optical microscope, electron microprobe, spectroscopic, X-ray diffraction (XRD), and various chemical analyses were performed. Batch screening tests gave qualitative estimates of leach rate and potential recovery. Packed column tests using hydrogen peroxide or pressurized oxygen gave more quantitative recovery estimates. The frequently friable sandstones contained highly variable amounts of quartz, feldspar, calcite, and clay, and in some cases, zeolite or mica. Clays were mainly mixed layer illite/smectite type. High cation exchange capacities (CEC's) correlated with clay (and zeolite) content, while high reducing capacities were often associated with pyrite level. Coffinite, in various environments, was the main uranium mineral. With batch tests using pseudo-first-order rate constants, ore leach rates were generally characterized as "fast" on a scale of fast, intermediate, and slow. However, there was variability in leach rates, both in samples from different areas and in samples taken at different depths in the same well. Fast rates and recoveries greater than 80% were observed in most column pack tests, but there was variation with leachate composition and sample source. The chemistry and kinetics of leaching are also discussed.
Carbon Dioxide Flooding Evaluation of High-Pour-Point, Paraffinic Red Wash Reservoir Oil
Authors: Frimodig James P. , Reese Norman A. , Williams Craig A. 
Published: December 2007

Abstract
Engineering methods are being developed to evaluate reservoir fluid systems for suitability to CO2 flooding. This paper presents our evaluation procedure as applied to laboratory data for a high-pour-point [95°F (35°C)] oil from the Red Wash field in Utah. The data were obtained from phase behavior and slim tube experiments.
The results of this work indicate that high pressures are required for a miscible displacement of the highly paraf-finic, high-pour-point Red Wash oil. The minimum miscibility pressure (MMP) was found to be 4,650 psia (32 060 kPa), increasing only 5% to 4,900 psia (33 784 kPa) when the injected CO2 contains a 10 mol% nitrogen contaminant. These pressures are not currently economically obtainable in the Red Wash field.
The Relationship Between Rate of Return, Payout and Ultimate Return in Oil and Gas Properties
Authors: Phillips Charles E. 
Published: December 2007

Abstract
Rate of return is being recognized more widely as a measure of the attractiveness or profitability of investments in oil and gas properties. "Rate of return" is that interest rate which results in the discounted present worth of future net income being equal to the initial investment in the property. It is usually calculated by means of trial-and-error. In this paper a factor, called "composite decline-discount factor," is introduced which eliminates trial-and-error for properties having constant percentage decline. Formulas have been derived and charts plotted showing the relationships between rate of return, payout, ultimate return, market value expressed as a fraction of discounted present worth, and "average annual rate of return". Rate of return on equity capital in oil payment transactions is also investigated.

Introduction
The evaluation of a proposed drilling prospect or purchase of a producing property does not end with a report giving its cost and estimated net income by years. Management must have some criterion or yardstick for judging the attractiveness or profitability of the project.
Probably the most common criteria are payout and ratio of ultimate return to investment. Their disadvantage is that they represent two independent yardsticks and do not give a single, unique answer to the question, "How attractive is this project?" For example, which is more desirable, a property having a three-year payout and an ultimate return-investment ratio of 2 to 1, or one having a five-year payout and an ultimate return-investment ratio of 3.5 to 1?
To answer this type of question, various methods for measuring the earning power of invested capital have been applied to oil and gas properties. One of particular merit is the rate of return method, also called the internal rate of return method, the discounted cash flow method, or the investor's method. Rate of return is that interest rate which results in the discounted present worth of future net income being equal to the initial investment in the property.
Internal Flows in Geothermal Wells: Their Identification and Effect on the Wellbore Temperature and Pressure Profiles
Authors: Grant Malcom A. , Bixley Paul F. , Donaldson Ian G. 
Published: December 2007

Abstract
Geothermal wells exhibit a variety of internal flow effects caused by the flow of water, steam, or both between distinct permeable zones tapped by the well. These internal flow effects are described and it is shown how they may be recognized from downhole pressure and temperature profiles.
Pressure transients measured at depths other than that of the well's primary permeable zone can be corrupted by such flows. The effects of such flows on injection and discharge transients are discussed.