bluuebunny/crossref_metadata_2025_split huggingface dataset:
An Improved Blotter Model for Analog Studies
Authors: Fothergill C.A. 
Published: December 2007

Abstract
An improved blotter model is described which makes use of a plastic sheet as base for the blotter field and pins to represent the input wells. The model is simple to construct and adapt and is particularly useful for demonstration purposes. Operational details are given.

Introduction
The blotter model was first applied to the investigation of oilfield problems by Wyckoff, Botset and Muskat, primarily in order to demonstrate the flood patterns which could be expected from various arrangements of input and output wells in waterflooding projects. In recent years the model has been largely superseded for analog studies by the potentiometric and electric analog models which are more refined and versatile, since they can simulate the form, and, in certain cases, permeability variations which it is not possible to do with the blotter model. However, the latter is still used for analog studies where the reservoir can be represented as being uniform in thickness and permeability, and where a visual record of the flood advance is required. Ramey and Nabor, for example, have applied the model to the investigation of areal sweeps in oil recovery by in-situ combustion.
Because of its limitations, the blotter model can be used in general for only very simple arrangements of input and output wells, but within these limitations it has a definite advantage over all other types, in that it provides a picture of the advancing flood using the simplest and most easily constructed apparatus, by contrast with the gelatin model, for example, which requires more elaborate equipment. Moreover, the experiments can be quickly repeated and modified if necessary, whereas considerable time is required to prepare a gel field, compared with that required for the preparation of sheets of conducting blotting paper.
For these reasons the blotter model can be very useful for demonstration and teaching purposes, enabling the student to experiment for himself with different arrangements of input and output wells.
Evidence of Chromatographic Effect During Flow of Gases Through Oilfield Cores
Authors: Roper W.A. , Doscher Todd , Kobayashi Riki 
Published: December 2007

Introduction
The chromatographic effect refers to the separation of constituents in a moving fluid phase which occurs when the phase is passed over a stationary phase, either solid or liquid, or large areal extent. In performing chemical analyses, the large surface contact area is provided in the case of gas-solid chromatography bypassing the gas over a porous solid and for gas-liquid chromatography bypassing the gas over a porous solid which has been coated with a nonvolatile liquid. The porous medium is usually placed in a cylindrical tube, although it may be a relatively flat sheet as in paper chromatography.
According to one theory, the separation results from the difference in time spent by various components in the stationary phase. A gaseous component which is completely insoluble in the stationary phase, or is not adsorbed on the solid, proceeds unimpeded through the column.
The versatility and power of the various types of chromatography for the analysis of complex mixtures are evident from their widespread use in performing chemical analyses and from the large number of symposia, books, and papers devoted to the subject in recent years. Associated developments are the application of chromatography to the determination of heats of solution, heats of adsorption, solubilities or K-values, etc.
Gas-liquid chromatography analyses may be characterized by the manner in which the samples are introduced and displaced from the column. The three techniques used are known as(1) frontal analysis, (2) displacement analysis, and (3) elution analysis. The frontal analysis is performed by displacing an inert gas from the column by a continuous stream of the sample.
As indicated in Fig. 1(A), all but the first fraction leaving the column represent mixtures rather than pure components. The displacement analysis is conducted by filling the column with a sample, then displacing it with a more strongly adsorbed or absorbed vapor. The resulting chromatogram is illustrated by Fig. 1(B). Finally, in the elution analysis a small sample of the mixture to be analyzed is introduced as a "plug" into a flowing stream of carrier gas to give an elution-type chromatogram, Fig. 1(C). The three techniques may be used to provide models to which flow patterns in other physical situations may be compared.
An In-Situ Combustion Process Simulator With a Moving-Front Representation
Authors: Hwang M. K. , Jines W. R. , Odeh A. S. 
Published: December 2007

Abstract
This paper describes THERMS, a new three-phase, black-oil simulator for in-situ combustion processes. The model also can simulate steam and hot-water injection operations. To simulate field-scale in-situ combustion projects, THERMS uses experimental data obtained from laboratory combustion-tube runs. Detailed kinetics and thermodynamic relations are not used. The model treats the burning zone as a moving front. The front is viewed not only as a moving heat source, but also as a displacement pump enhancing oil flow. This approach results in a new algorithm. The model has been designed with strongly field-oriented features. Its utility is illustrated by a history-matching study of the South Belridge, CA, dry-combustion pilot test.
Neutron-Induced Gamma Ray Spectroscopy for Reservoir Analysis
Authors: Westaway Peter , Hertzog Russel , Plasek Ronald E. 
Published: December 2007

Abstract
The weighted least-squares (WLS) approach to spectral analysis has enabled more information to be extracted from the downhole recorded induced gamma ray spectra than was previously possible. GST™ (gamma ray spectroscopy tool), with its optimized inelastic and capture spectral modes, permits analysis of most and often all significant elements present in the formation and provides the possibility of evaluating hydrocarbons, salinity, lithology, porosity, and shaliness.
Data have been obtained in a wide range of conditions in open and cased holes with the GST tool both in its present and experimental versions. This paper presents field examples to demonstrate the versatility and potential of the technique, not only as an effective oil-finder independent of water salinity conditions but as a valuable input to a more complete interpretation of well logs.
Case Study of a Multiple Sand Waterflood, Hewitt Unit, OK
Authors: Ruble David B. 
Published: December 2007

Summary
Synthetic two-component mixtures (uraninite and iron sulfide) as well as native uranium ores obtained from Texas and Wyoming have been examined. Physical/chemical ore properties are correlated with observed laboratory leach response. Data show a large inherent selectivity of oxidant for uranium in the early stages of a leach period. Uranium head grade was found to increase in a nearly linear fashion with hydrogen peroxide concentration in the leach solution. As uranium in the ore is depleted, uranium response decreases and the oxidant serves mainly to leach iron sulfide gangue material.

Introduction
Uranium historically has been mined by two methods, open pit (strip) or underground shaft mining. These two methods require high-grade uranium deposits to justify the large investment of personnel and material required to process the uranium into saleable form. New reserves of high-grade uranium ore are not being discovered in large quantities, indicating the need to locate new types of uranium deposits to fill future demands of the nuclear power industry. New sources of uranium exist in the form of low-grade ore deposits approximately 60 to 600 m below ground level. Recovery of some of these low-grade deposits became economically feasible when the price of uranium increased in the early 1970's. It is too costly, however, to mine these uranium deposits by conventional techniques (i.e., open pit or underground shaft), so a new mining method was developed. This new method is known as in-situ leaching or solution mining and involves selective leaching of the uranium from the ore deposit by use of a special solution injected into the ore body. Ore body composition and leach solution chemistry have a large effect on uranium recovery and are investigated in this study.

Chemistry
Uranium present in an ore body is generally in the reduced tetravalent (U+4) state and first must be oxidized to the more soluble hexavalent (U+6) state before it can be leached. Various oxidants are available, with hydrogen peroxide and molecular oxygen being the most widely used in commercial practice. Aside from uranium, an ore body contains other oxidant-consuming species such as pyritic iron sulfides and carbonaceous material (Table 1). Uranium leach chemistry can be described best by the following equations, with hydrogen peroxide (H2O2) as oxidant.
(1)
(2)
(3)
(4)
(5)
Eqs. 1 and 2 describe uranium oxidation and solubilization, respectively. Oxidant is added to a leach solution composed of either sodium or ammonium carbonate, and is injected into the ore body. Dissolved uranium is transported through the ore body to the recovery wells in the form of a uranyl carbonate complex. Eqs. 1 through 5 show that more oxidant can be consumed by oxidation of the iron sulfide and carbonaceous gangue materials than by uranium itself.
JPT
P. 937^
Acoustic Emissions as a Tool for Hydraulic Fracture Location: Experience at the Fenton Hill Hot Dry Rock Site
Authors: Albright James N. , Pearson Christopher F. 
Published: December 2007

Abstract
Microearthquakes with magnitudes between −6 and −2 have been observed in three successive massive injections of water at the hot dry rock geothermal energy development project's demonstration site at Fenton Hill, NM. The injections were part of a program to increase the heat transfer area of hydraulic fractures and to decrease the flow-through impedance between wells in the energy extraction system under construction. The microearthquakes were used in mapping the location of the extended hydraulic fractures.
The large shear- to compressional-wave-amplitude ratio observed in the signals suggests that the microearthquakes result from shear failure, probably on preexisting planes of weakness that intersect or make up the main hydraulic system. Failure resulting from increased pore pressure is a likely cause for the microearthquakes. Knowledge of the failure criterion for the reservoir rocks permits calculation of the pore pressure increases necessary for failure. At Fenton Hill, it appears that pressures 2 Pa (0.00029 psi) above hydrostatic are necessary. For this hypothesis of microearthquake occurrence to hold, the effective reservoir permeability must be four orders of magnitude above that for the bulk rock, as would be the case if there were permeable joints or fractures in the reservoir before hydraulic stimulation.
Non-Plugging Emulsions Useful as Completion and Well-Servicing Fluids
Authors: Priest G.G. , Allen T.O. 
Published: December 2007

Abstract
The development and use of nonplugging emulsions has provided a solution to certain problems associated with completing and reworking wells which have plagued the industry for years.
In the present work emulsions free of insoluble solids have been developed for use in wells with temperatures up to 250°F and with pressures requiring densities up to 12.5 lb/gal. They possess the required properties of a satisfactory fluid for completing and reworking wells; they are non-plugging, they exhibit a low fluid loss, and they have a controllable density.
Non-plugging emulsions have been used in approximately 200 completion and well-servicing operations. They were positioned to cover the interval to be perforated or to protect existing perforations during workover operations. Comparative data from several wells show that the productivity indices of wells perforated in the emulsions were substantially higher than the productivity indices of offset wells perforated in mud or water. Fewer difficulties in servicing wells and in getting wells back on production were experienced when emulsions were used as protective fluids to prevent water or mud from contacting exposed formations. In one field, the use of emulsions as perforating fluids has reduced the incidence of expensive sand control measures.
Precautions should be taken to avoid contamination of drilling muds and cements by the emulsions. Contamination can be avoided in most operations by following careful placement procedures.

Introduction
Research conducted during the past few years has demonstrated that perforations are often plugged by debris from the perforator, pulverized sand from the formation, and mud solids when drilling mud is in the casing at the time the perforations are made. This plugging of perforations causes numerous problems in the completing, producing, and repairing of wells. For example, low well productivity, sand production, premature gas or water production, and failure of squeeze-cementing jobs are but a few problems recognized as being aggravated by plugged perforations.
G-2 and G-3 Reservoirs, Delta South Field, Nigeria: Part 2 - Simulation of Water Injection
Authors: Thakur G.C. , Stanat P.L. , Aruna M. , Poston S. 
Published: December 2007

Summary
To date, laboratory experiments to evaluate a fieldprospect for CO2 flooding have concentrated on determining minimum miscibility pressure. Other experiments include core floods and single- and multiple-contact phase behavior studies. This paper discusses relationshipsbetween the various experiments in the light of current understanding of the mechanisms operating in the CO2-flooding process. Objectives and limitations ofeach experiment are discussed. Limitations on the use of the resulting data to estimate recovery from field CO2 floods also are reviewed. A new experimental procedure is described that permits rapid determination of phasebehavior and fluid properties of CO2 /crude-oil mixtures at reservoir conditions. The experimental procedure, which involves continuous contacting of the reservoirfluid with CO2, can be used efficiently to obtainphase-behavior and fluid-property data that would require difficult and time-consuming experiments if obtained bypreviously available techniques.

Introduction
Although CO2 flooding has been investigated since theearly 1950's, consensus has not developed as to thelaboratory experiments required for the evaluation of a CO2-flooding prospect. Laboratory experimentsperformed most often, however, fall into three generalareas:slim-tube displacements,core displacements, andhigh-pressure volumetric (PVT)and vapor/liquid equilibrium (VLE) experiments.
Thethree types of experiments yield different information about a potential CO2 flood. This paper reviews brieflythe uses and limitations of the information obtained inthe various laboratory experiments.
Design of any large-scale CO2 flood inevitably involves the use of numerical reservoir simulators. Those applicable to CO2 flooding also fall into three general groups:miscible simulators,compositional simulators, andhybrid miscible/compositional simulators.
The type of data required to support a simulation effort depends (in part, at least) on the choice of the simulator. Miscible simulators based on the work of Todd and Longst afftreat CO2 as completely miscible with theoil, and require little more than the permeability, relative-permeability, capillary-pressure, viscosity, anddensity data common to black-oil simulators. Routine reservoir-fluid volumetric and fluid-property measurements, in addition to standard core characterizations (permeability, relative permeability, and capillary pressure), are adequateto support such simulations.
JPT
P. 888^
The Fry In Situ Combustion Test-Reservoir Characteristics
Authors: Hewitt C.H. , Morgan J.T. 
Published: December 2007

Abstract
The Fry cocurrent in situ combustion project was carried out in a 3.3-acre portion of a lenticular body of Robinson sandstone of Lower Pennsylvanian age. This particular sand body is about 12,000 ft long and 3,500 ft wide; it varies in thickness from 0 to 55 ft, trends northeast-south west, and occurs at depths between 880 and 936 ft. The reservoir is made up of three distinct types of sandstone, each having characteristic reservoir properties. (See Table 1.)Textural gradients, sedimentary structures, erosional basal contact, absence of marine fossils, and geometry of the sand body all indicate that the sandstone is of fluvial origin and part of an extensive complex of river-deposited sediments. Geographically oriented cores reveal that the direction of depositing currents was to the southwest, parallel with the sand-body trend. Directions of maximum permeability also parallel the northeast-southwest trend. The layered nature of the sandstone reservoir and its directional properties have controlled the areal distribution of produced gas, the ignition behavior, and the vertical profile and horizontal extent of the combustion zone.
Introduction
This paper is the first of a series of three papers that describe Marathon Oil Co.'s Fry in situ combustion test. This first paper contains the results of a detailed study of the geology and reservoir characteristics of the Robinson sandstone reservoir in which the Fry test was conducted. The second and third parts of this series report on the field operations and performance. The geologic work related to cores cut through the combustion zone, and to the effect of reservoir properties on the combustion process is included in the third paper.
GEOLOGIC STUDY OF THE FRY RESERVOIR
The close spacing of continuous cores in the Fry combustion site provided an unusual opportunity to study the details of distribution of lithology and reservoir properties within a petroleum reservoir. The objectives of the study were:1. To determine the distribution of rock types within the Robinson sandstone in the Fry area;2. To determine the relationship of porosity and permeability to rock properties and establish the distribution and homogeneity of reservoir properties;3. To determine the origin of the Robinson reservoirs so that attempts could be made to predict the size, shape, distribution, extent and continuity of Robinson reservoirs; and4. To determine what effects, if any, the reservoir rocks might have on the combustion process, so that the process might be better evaluated.
AVAILABLE MATERIALS
Continuous cores were cut from 14 wells in the vicinity of the Fry site. Ten of the cores are from within the 3.3-acre pattern; six of the 10 were cut prior to combustion, and four were cut through the combustion zone.
JPT
P. 337ˆ
The Fry In Situ Combustion Test-Field Operations
Authors: Clark G.A. , Jones R.G. , Kinney W.L. , Schilson R.E. , Surkalo H. , Wilson R.S. 
Published: December 2007

Abstract
This paper describes the field operations at the Fry in situ combustion project in Crawford County, Ill. Field operations may be divided into three phases preliminary engineering studies of 1960 and 1961, ignition, and, finally, operation of the test. The Fry combustion project was a pilot test of cocurrent in situ combustion on a 3.3-acre inverted five-spot. In the summer of 1960, air injection tests were conducted using old wells in the area and a new air injection well drilled especially for the test. In the summer of 1961, four new oil wells were drilled on a 3.3 acre pattern for the pilot test. All old wells in the near vicinity of the pilot test were abandoned to preclude any possibility of gas escaping to adjacent formations. A compressor plant was also installed at the test site in 1961. Air injection tests and other engineering studies were made. At the conclusion of these tests, ignition was accomplished with a 40 kw electrical igniter. Operation of the Fry combustion test was little different from the usual oilfield operation with the exception of the high rate of air injection. No difficulty was found with the openhole completion. There were no unusual corrosion or emulsion problems until bottom-hole temperatures exceeded 150F. Four cores were drilled into the burned-out portion of the reservoir with no mechanical difficulties.

Introduction
A cocurrent or conventional in situ combustion test was conducted on the Fry unit of the Marathon Oil Co., in Crawford County, Ill. Besides testing combustion in the Fry type of reservoir, the test was intended to evaluate various operating procedures. This paper presents a discussion of the Fry combustion test field operations. The geology of the reservoir and the test performance are discussed in other papers.

HISTORY OF THE FRY UNIT
The Fry unit consists of 11 leases totaling 337 acres in an area in which oil was originally discovered in 1906. Production from this reservoir, as from all Robinson sand reservoirs in the area, was very high during the first few years. As the dissolved-gas energy was dissipated, early attempts to retard the decline consisted of vacuum, air, and gas repressuring, and recently, most of the area has been subjected to water flooding. Following early air repressuring, the Fry waterflood unit was formed and water flooding initiated in July, 1952. In the area in which the Fry combustion test was conducted, a peripheral water flood of a 160-acre area was developed as shown in Fig. 1. Between 1956 and 1960, it became apparent that the water flood was unsuccessful. In looking for a suitable site for an in situ combustion test, the Marathon Oil Co. selected the Fry unit as possessing those features most desirable for such a research project. Field operations associated with the Fry combustion test began in the spring of 1960.
JPT
P. 343ˆ
Evaluation of Porosity Derivation from Neutron Logs
Authors: Widmyer R.H. , Wood G.M. 
Published: December 2007

Abstract
In order to evaluate the quantitative determination of porosity by various neutron logging systems, four test wells were constructed to simulate some of the possible variables found in field logging conditions. All of the test holes contain sections of limestone with one section of sandstone included in one well. Each well has a representative section of high, medium, and low porosity. Three borehole sizes are represented by three of the test wells, all containing fresh water. One test well contains saturated brine. Statistical and time constant checks are made for each system evaluated. Runs and repeat runs are made with the son de centered and eccentric. Factors evaluated are the effect of borehole size, sonde position, salinity, chemical composition of rock, and statistical variation. A semi-quantitative method of evaluation of these effects is used giving the average maximum per cent error possible for each. Drift and calibration procedures are also discussed. The effect of the various factors appears to be largely a function of the phenomena detected as well as the means of detection. Graphic illustrations of some of these effects are presented. It is concluded, that for accurate log interpretation, the hole size and sonde position should be known.

Introduction
The use of neutron logs for the derivation of porosity has become an accepted practice in many areas. In recent years, many different neutron logging systems have been offered to the industry. The neutron sources presently available are of the radium-beryllium or polonium-beryllium type. Detector types used are ionization chambers, Geiger-Mueller-type counters, proportional counters, or scintillation detectors used to detect or measure gamma rays, thermal neutrons, epithermal neutrons, fast neutrons or combinations of these. It is well-known that all systems do not respond alike in all environments. As a result, testing facilities and an evaluation method were developed for use in evaluating the porosity discriminating ability of neutron logging systems using conditions simulating those normally encountered in the field. With such an evaluation, the suitability of a logging system can be determined for selected field conditions.