bluuebunny/crossref_metadata_2025_split huggingface dataset:
Isobaric Heat Capacities of Natural Gases at Elevated Pressures and Temperatures
Authors: Abou-Kassem J. H. , Dranchuk P. M. 
Published: December 2007

ABSTRACT
A new correlation has been developed for ideal isobaric heat capacity for natural gases. It is applicable over the temperature ranges of 32 ≤ T°F &lt; 2240 and 32 &lt; T°F &lt; 300 for sweet and sour gases respectively. In addition a new generalized mathematical correlation was developed for the isobaric heat capacity departures, for such gases, which is applicable over the range of variables 0.2 ≤ Pr ≤ 15 and 1.05 ≤ Tr ≤ 3.0. This latter correlation is based on a reduced form of the BWR equation of state.
Both correlations are adaptable to computer application. Comparisons with data from the literature are presented and discussed.
Water Can Be Controlled in Air and Gas Drilling
Authors: Hower Wayne F. , McLaughlin Charles , Ramos Joe , Land John 
Published: December 2007

Abstract
The control of water in air-drilled wells is a difficult problem and quite different from conditions normally encountered in oil producing wells. To evaluate better the many materials developed by laboratory research, several relatively shallow wells were drilled adjacent to the Research Center. In this way, materials and placement techniques could be evaluated under controlled field conditions. The research program, to date, has developed two distinctly different materials that promise to be adaptable for most of the varied water control conditions encountered in the industry. One material is a very low viscosity solution that, with time, sets to form a stiff gel. The other is a liquid synthetic resin that can be used by itself or in a slurry with fluid loss additives. The resulting set of the resin or slurry is strong and is capable of holding back higher pressures than the stiff gel. Both the stiff gel and resin materials have been applied successfully in the designed use and are also being successfully applied in other water control problems. The material that sets to form a stiff gel is particularly adaptable for many types of fluid grouting problems where stabilization of soil as well as water control is desired.
Research is continuing in an effort to improve the present materials and placement techniques. New ideas are also being investigated. One is a gaseous system that has given encouraging results in initial tests.

Introduction
The substitution of air or gas for all or a part of the mud used in drilling for hydrocarbons has presented a new and difficult problem to the industry. This problem is the economic control of water that is normally suppressed by conventional heavier muds.
Many papers have been published during the past few years describing practically every aspect of "air" drilling. Increased drilling rates and longer bit life have been reported which have contributed to significant savings in rig time. The resulting economic advantage has varied for different areas and, where no particular troubles were encountered, savings were phenomenal. As experience was accumulated in this type of drilling, its advantages and disadvantages became more exactly defined. In some instances, the disadvantages outweighed the advantages and caused a cessation of this type of drilling in the particular area. In almost every case, influx of water to well bore was the major cause for return to conventional drilling methods.
All kinds of water production have been encountered and each type presents its own particular problem. The weeping or very low water producing zones provide enough water to wet the cuttings but not enough to flush them out of the hole.
Underground Coal Gasification of Steeply Dipping Beds: A Second Generation Synthetic Fuels Process
Authors: Davis Burl E. , Ahner Paul F. 
Published: December 2007

ABSTRACT
In situ gasification of steeply dipping coal beds (UCG-SDB) has significant advantages over the more conventional horizontal UCG. In fact, the UCG-SDB process appears to be both technically and operationally competitive with surface gasifiers. The results of the Rawlins UCG-SDB field test program suggest that the process can compete with more conventional sources of synthesis gas on an economic basis. The SDB process mechanism has several advantages over the horizontal process and performs in a fashion similar to surface packed-bed reactors. The oxygen requirements for the process are quite low and the degree of process control observed at Rawlins is very attractive.
Geology of Post West (Strawn) Field, Garza County, Texas
Authors: Myers Sherris R. 
Published: December 2007

ABSTRACT
Post West (Strawn) Field, in Garza County, Texas, has a structurally and stratigraphically controlled hydrocarbon trap. The field produces oil from a structure with fifty feet of closure in two of four reservoir zones. The geologic study of the Strawn reservoir described in this paper should aid in hydrocarbon reserves calculations.
Polycrystalline Diamond Compact Bit Hydraulics
Authors: Knowlton R. Helene , Huang Hsin 
Published: December 2007

ABSTRACT
It is well understood and documented that bottom-hole hydraulics plays an important role in conventional diamond bit performance. Recent industry experience has shown a similar importance with the new synthetic diamond compact bits. Certain types of polycrystalline diamond compact bits have cutters arranged in a reverse spiral mode. For optimum performance bit hydraulic design should be tailored to that reverse spiral mode. Theory reveals that a bit built with rectangular nozzles with a long axis in the tangential direction can give a fluid velocity envelope similar to the envelope of the reverse spiral. A rectangle can also reduce bit plugging by providing an increased perimeter in a non-concentric geometry. The introduction of rectangular nozzles into the bit renders the regular round nozzle pressure drop equation unsuitable for direct application. Extensive hydraulic tests were performed with different configurations of rectangular nozzles to establish more accurate pressure loss equations. The experiments included single nozzle studies and laboratory and field tests of bits. Field test results confirmed the reliability of the results obtained in the laboratory studies.
The Effects of Shear and Proppant on the Viscosity of Cross-Linked Fracturing Fluids
Authors: Gardner David C , Eikerts John V. 
Published: December 2007

ABSTRACT
Several frequently used cross-linked fracturing fluids, hereafter referred to as gels, have been evaluated as to the effects that shear and that 20/40 mesh sand proppant have on their rheological properties. A closed-loop pipe viscometer was used to evaluate the shear resistance and post-shear recovery of various gels as a function of pH, cross-linker type, polymer concentration, shear intensity (shear stress and shear rate), and shear duration. The aqueous-base gels that were tested included those made with guar, hydroxypropyl guar (HPG), and carboxymethyl hydroxyethyl cellulose (CMHEC) polymers. Selected aqueous-base gels were also evaluated as to the effect on slurry viscosity of varying concentrations of 20/40 mesh sand proppant.
Test results indicate that when cross-linked with borate ions, guar and HPG gels have the greatest resistance to shear. Yet when cross-linked with various titanates, HPG gels showed significantly lower resistance to induced shear. Tests on CMHEC gels which were cross-linked with trivalent aluminum (Al+++) indicate a shear resistance between that of the HPG-borate gels and that of the HPG-titanate gels. Also tested was post-shear recovery or the percentage of viscosity increase following high shear exposure as correlated to field tubular pumping conditions. The HPG-borate gels and the CMHEC-Al+++ gels demonstrated considerably higher post-shear recoveries than those attained with HPG-titanate gels. In addition, the effect of 20/40 mesh sand on the viscosity of gels is a larger increase in slurry viscosity in the fracture than that predicted from Newtonian slurry mathematical models.
Finally, laboratory study indicates that the actual slurry viscosity, accounting for shear and proppant effects within the fracture, is apparently moderately to extensively lower than that predicted by conventional rheological methods.
Laboratory Evaluation of In-Situ Stress Contrast in Deeply Buried Sediments
Authors: Abou-Sayed A. S. 
Published: December 2007

ABSTRACT
Delineation of the effects of in-situ stress contrasts on fracture containment requires the field measurement of the minimum horizontal in-situ stress of the pay zone and adjacent layers. Small hydraulic fracturing tests are presently the most practical method with which to determine the state of stress acting at great depth within the earth.
Several attempts have been made to correlate the state of stress of a rock layer and its current mechanical properties. Recently techniques for the independent determination of P- and S-waves during wellbore logging have been implemented by the logging service industry. Such advances help establish a more reliable value for the in-situ rock elastic properties, namely Young's modulus and Poisson's ratio. Higher Poisson's ratio value has been proposed as an indicator of higher minimum horizontal in-situ stresses. This is compatible with trends for reservoirs in the Louisiana/Gulf of Mexico area where clean sandstone pay zones are prevalent. Burial history and rock constituents may alter such conclusions.
Although correlation with Poisson ratios of the various formations may provide rough estimates of horizontal stress gradients, they are inadequate to ascertain which of two adjacent formations has the higher horizontal stress, especially in tight reservoirs where the clay content in the sandstone layers is high and the differences between sandstone and shale layers diminish. Inelastic deformation, as well as changes in material properties and strain during the burial history have a significant influence on today's state of stress at depth. Furthermore, correlation of direct in-situ stress measurements with general laboratory response of granite, sedimentary rocks and salt formation to applied loads imply that soft, high ductility material (higher principal strain ratio during inelastic flow) as well as materials not capable of sustaining large deviatoric stress (low ratio of deviatoric stress to mean stress in uniaxial strain deformation) possess higher minimum horizontal stresses (cf. Abou-Sayed, et al., 1981).
In the absence of direct, field-measured in-situ stress data, special laboratory tests are presented here with analysis to provide a suggestive basis for evalution of in-situ stress contrast within different layers for fracture containment analysis. The laboratory tests presented in this paper are aimed at providing the mechanical properties of the rock layers under two deformation histories: 1) triaxial compression tests to determine the elastic moduli of rocks, and 2) one-dimensional (uniaxial) strain tests to delineate the long-term correlation between horizontal and vertical stresses within the various layers. Tests to measure the coefficient of thermal expansion of rocks under simulated in-situ conditions may also be performed.
The laboratory-deduced stress contrasts in various rock types are compared to field-measured data. Several case studies are presented and close agreements are observed.
The Petroleum Industry and the European Economic Community
Authors: Matthiessen Hans Heinrich 
Published: December 2007

Introduction
World War II left the economies of large parts of Europe in a state of devastation. The population had sustained heavy losses in life. A huge number of industrial plants and homes lay in rubble. Monetary systems had broken down. Europe's political and economic structure was materially changed by the erection of an "Iron Curtain" between the Eastern and the Western half of the continent. Reconstruction began with the production of basic necessities - food, clothing, homes. It formed the basis for the reversal of the downward trend in European economic development. Two circumstances were responsible for the success that in the free part of Europe the rehabilitation could be implemented: first, the possibility of developing under a free enterprise system and, second the Marshall-plan aid which the United States had offered to all countries in Europe, but which, most regrettably, only the free countries in Europe were in a position to accept. To this day the free Europeans are deeply grateful for this real and timely help by the American people. It did not take long for Europeans to realize that sustained economic growth and political harmony could be maintained by the creation of economic and political unity for Western Europe. One group of European countries formed E.E.C., the European Economic Community. This area is shown on Fig. 1. The countries representing the group of countries which founded a somewhat looser organization, EFTA, the European Free Trade Association are also shown. Let me add that, together, EFTA and E.E.C. encompass about 85 percent of the population of free Europe. In 1962. the EFTA countries had about 91 million inhabitants as compared to 176 million in the Common Market area as shown in Table 1. Many people in Europe hope that the day will come when a merger between E.E.C. and EFTA will occur and one great European Economic Community will be established. This, of course, is going to he a lengthy, difficult process.

THE COMMON MARKET AND ECONOMIC GROWTH
The Common Market became the core of the European Economy. In the so-called Rome treaties of 1957 the six E.E.C. partners agreed that by 1969 at the latest, all tariffs will have to be abolished in the trade among member countries and uniform tariffs will believed in the trade with non-member countries. Also, an effort will be made to harmonize the tax systems of the member countries. A further step which has not yet been worked out in detail would be the creation of a uniform currency system for the Common Market. In the other fields as well, definite measures have been agreed upon. For instance, a large degree of uniformity was established in antitrust legislation.
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Simulation of Gas Production From a Reservoir Containing Both Gas Hydrates and Free Natural Gas
Authors: Holder Gerald D. , Angert Patrick F. 
Published: December 2007

ABSTRACT
A three dimensional finite-difference simulation of heat and mass transfer in a reservoir containing stratified layers of gas hydrates (50 ft.) and free natural gas (50 ft) was made. Results indicate that in this volumetric depletion gas reservoir, hydrated gas can contribute about 20 to 30% of the total gas production. This is due to hydrate dissociation as the pressure in the reservoir is reduced. These percentages represent an estimate for a gas reservoir which is produced at the rate of 2.5 MMCFD. The thermal capacity of the reservoir is more than sufficient to provide the energy necessary for hydrate dissociation into gas or water.
Another Concept for Final Buildup Pressure
Authors: Mead Homer N. 
Published: December 2007

Abstract
A method is developed for determining final static reservoir pressure buildup based upon the assumption that the change of the quantity [Ps - Pw] decreases at a constant rate with time. It is actually an application of the infinite series. The pressure measured in the well is assumed to be the average static reservoir pressure less the additive effect at any one time of the differential in pressure across the skin, differential in pressure between the higher permeability parts and the surface of the rest of the reservoir bounding them and differential in average pressure at the boundary of the higher permeability parts and static reservoir pressure. Thus the actual plot of the log [Ps - Pw] may be the addition of several straight line functions at any one particular time. A great deal of field data has been analyzed using this method; results indicate that it is capable of giving accurate results in every case. Other information besides final static pressure buildup may be obtained from the plot of log [Ps - Pw] vs shut-in time.
The method presented in this paper has the following advantages:The time the well is produced prior to shut-in is not required.The skin effect or damage ratio can be observed from the plot of log [Ps - Pw] vs shut-in time at a glance.A qualitative measurement of the effect of the non-uniformity in permeability of the reservoir can be made.

Introduction
In 1937, M. Muskat proposed that the log of Ps - Pw would form a straight line when plotted against shut-in time during pressure buildup.
Vertical, Conformance in an Alternating Water-Miscible Gas Flood
Authors: Stone Herbert L. 
Published: December 2007

ABSTRACT
Oil recovery by the injection of water alternately with gas (WAG flooding) is often limited by gravity segregation, which causes the injected gas to rise to the top of the formation and water to migrate to the bottom. This segregation results in a miscible flood in only a thin layer at the top of the formation, whereas the remainder is waterflooded. However, vertical conformance in a WAG flood can be greatly improved by use of injection rates that are high relative to well spacing. The degree of improvement and, hence, the resultant oil recovery is primarily a function of a single dimensionless parameter, which is one form of the viscous-gravity ratio.
Dual Porosity CNL Count Rate Processing
Authors: Scott H. D. , Flaum C. , Sherman H. 
Published: December 2007

ABSTRACT
The standard method of computing porosity for the two-detector Compensated Neutron Log (CNL) is to use the ratio of near to far detector count rates. This procedure has the advantage that, to first order, environmental effects tend to cancel, leaving only residual effects to be corrected using a series of departure curves.
Recently, a new four-detector Dual Porosity CNL tool has been introduced which uses two epithermal neutron detectors in addition to the two standard thermal neutron detectors. Two separate porosity measurements are thus obtained, one from each pair of detectors. In clean formations, the measured porosities agree. However, in shaly formations containing high neutron absorbers the porosity measured by the epithermal detectors reads lower and agrees more closely with density derived porosity.
To maintain reasonable count rates, the epithermal detectors are spaced closer to the neutron source than the thermal neutron detectors. If ratio processing is used for the epithermal measurement, the computed porosity is more sensitive to borehole effects indicating a greater difference in the response of each detector to the borehole environment. As a result of a detailed study of the tool response to many environmental variables, a new data processing technique has been developed using individual detector count rates. The method is analogous to the "spine-and-ribs" analysis developed for the FDC tool.
Parameters which have been studied are borehole size, tool standoff, mudcake thickness, mud weight, borehole salinity, formation salinity, formation matrix, formation gas, temperature and pressure. Examples are given of how some of these parameters affect the individual count rates.
The new processing method can be used to compute both epithermal and thermal neutron porosity. In the latter case, however, additional input parameters relating to neutron absorbers should be specified. Count rate processing has two important advantages. First, it can provide a value of porosity much less sensitive to variations in borehole parameters, particularly tool standoff for the epithermal measurement. Second, the deviation of a data point from the spine can be a measure of the effective tool standoff. This parameter can be used as a basis for an adaptive filter of the neutron porosity. Examples illustrating the improvements obtained with count rate processing are presented.
Simulation of the LETC/DOE TS-1S Steam Drive Experiment
Authors: Hutchinson H. L. , Kennedy J. H. , Johnson L. A. , Fausett D. W. 
Published: December 2007

ABSTRACT
In conjunction with the LETC/DOE TS-1S Test, a computer simulation study was performed to a) help define the pattern size and configuration prior to the test, b) monitor the progress of the test during its operation, and c) help with post-test interpretation of the results. A multidimensional steamflood model was used to conduct the simulation. Results helped to define the inner and outer pattern sizes for the inverted 5-spot pattern. During the test vertical temperature profiles were matched which suggested significant under-running of the zone. Post-test coring and matching tended to confirm this behavior and the model also showed that initial oil saturation heterogeneity controlled the fluid movement during the experiment. The model results suggested that about three-fourths of the injected steam left the zone of interest and that fluid movement continued after the test was terminated. Studies of pre-steamflood air injection testing showed that such testing can give indication of areal heterogeneities so that steam movement during the test can be anticipated based on such heterogeneities.
Preliminary Findings From a Study To Perform Automated Metering and Control of Carbon Dioxide Injection With a Liquid Turbine Meter
Authors: Grassbaugh David P. , Kearney Carroll L. , Crane Tom L. 
Published: December 2007

ABSTRACT
With the advent of tertiary flood projects utilizing CO2 as an injection medium, the need to adequately measure and control it becomes imperative for achieving optimum injection to withdrawal ratios. Maintaining an optimum ratio is particularly important in the economic sense considering that the injection medium initially would not be available as a by product of production.
Preliminary data compiled from a study to perform automated volumetric metering and injection rate control of CO2, using the liquid turbine meter is presented in this treatise. Observations of CO2 flow within a temperature range of 29-104 deg/f and a pressure range of 950-1250 psig are made for two one-inch liquid turbine meters. The compiled data depicts measured turbine meter accuracy variations which may be controlled to within 6% of true flow by correction formulas that may be solved by digital or analog techniques.
Results of the Bell Creek Unit ‘A’ Micellar-Polymer Pilot
Authors: Aho Gary E. , Bush Jim 
Published: December 2007

ABSTRACT
Gary Energy Corporation has conducted a DOE cost-shared micellar-polymer pilot in the Bell Creek Field, Powder River County, Montana. This project was initiated in 1976 and has progressed through all phases (reservoir evaluation, continued secondary, process design, chemical injection and tertiary response) necessary to allow for a final evaluation.
Unexpected reservoir heterogeneity in the pilot area and the delivery of less-than-design quality sulfonates appear to have affected the chemical flood efficiency. Oil recovery in the confined portion of the pilot is expected to be 28% of the oil-in-place at the start of process injection. Approximately 40% of this recovery is considered to be incremental tertiary.
A summary of all aspects of the pilot will be presented including reservoir geology, chemical flood process design, computer simulation studies, process injection, oil treatment problems and an analysis of overall project performance.