bluuebunny/crossref_metadata_2025_split huggingface dataset:
Laboratory Study Indicates Significant Effect of Pressure on Resistivity of Reservoir Rock
Authors: Glanville C.R. 
Published: December 2007

Abstract
The effect of overburden and fluid pressure on the resistivity of reservoir rock has been generally ignored in the quantitative interpretation of electrical logs. This paper shows from laboratory tests of two sandstone, two limestone and one dolomite formation that theoretical reservoir stress increases resistivity in varying amounts, depending upon depth (or stress) of formation, porosity, texture of rock and degree of water saturation.
The increased resistivity develops from increased formation resistivity factor and saturation exponent. In medium to low porosity the formation factor vs porosity relation is affected in such a manner that a given porosity represents a higher formation factor in stressed rock. Indications are that pressure effect is probably significant in many reservoirs of medium to low porosity, especially at greater depths, and should be considered in the interpretation of their electrical log resistivities.
A simple and useful technique for pressure analysis of core plug samples was developed in the study which should be adaptable for routine measurements (Fig. 1).

Introduction
The electrical resistivity measurement of reservoir rock has long been recognized as a reliable indicator of many important properties of the rock and of the fluids which it contains. Efforts to derive practical methods for analyzing electrical log recordings have been directed along two lines:correcting the "apparent" log resistivity to a "true" value by considering effects of the borehole, bed thickness, measuring system, etc., andinterpreting the true value of resistivity for whatever data it may reveal which is of practical value in the detection and/or evaluation of an oil or gas reservoir.
This paper deals only in the realm of the second item.
Among the most important factors known to affect the reservoir rock resistivity are temperature, porosity, permeability, salinity of contained water, degree of water saturation and abundance of clay minerals or "conductive solids". Much progress has been made by many investigators to express the effects of these variables.
Reduction of Grid-Orientation Effects in Reservoir Simulation With Generalized Upstream Weighting
Authors: Frauenthal James C. , di Franco Roland B. , Towler Brian F. 
Published: December 2007

Abstract
A generalization of upstream weighting is proposed as a method for reducing grid-orientation effects in reservoir simulation. For the two sample problems studied, a piston-flow waterflood and a realistic gas injection, the grid-orientation effect was almost completely eliminated. The new generalized upstream weighting (GUW) method is particularly attractive because it is fast and accurate, and can be added easily to an existing simulator that uses upstream weighting.
Analysis of Tight Gas Well Production Histories in the Rocky Mountains
Authors: Hale Brent W. 
Published: December 2007

Summary
Monthly production records on more than 6,000 gas wells are analyzed to determine expected behavior of additional wells and to compare actual performance with theoretical performance as described by many authors. The wells analyzed are in the Rocky Mountains, ranging from the Green River basin of Wyoming to the San Juan basin of New Mexico. Most of these wells produce from low-permeability reservoirs and have been hydraulically fractured.
Production trends are studied with three different techniques: conventional semilog rate vs. time analysis, logarithmic rate vs. time analysis, and linear flow decline-curve analysis. The primary purpose of this study is to forecast future rates and reserves. The impact of well downtime and pressure variations on observed flow rates is reviewed.
Drilling From Floating Vessels Now Economically Carried Out Off California Coast
Authors: Rand W.W. 
Published: December 2007

Introduction
Deep water occurs at short distances off the California coast, restricting the economic use of artificial islands and bottom-based platforms to a narrow coastal strip. Beginning in 1950, drilling from floating vessels has proved to be feasible and economically sound, and operators are now seeking methods of drilling oil wells from vessels. Significance of results so far achieved has made little impression on the industry, but extension of techniques now in use forecasts widespread use of floating drill rigs.

Search for California Tidelands Oil Began in 1945
Marine seismic methods were first used off the California coast in 1945, inaugurating the tidelands oil search program. In 1946 submarine coring began, with a simple weighted core tube, for sampling pre-recent formations efposed on the sea floor.
In order to take cores from formations buried by overburden, a jet tube and punch core device operable through the jet tube was developed. Early forms required a diver to guide the core tube into the jet tube after the hole had been jetted through overburden by high pressure sea water. Later improvements permitted dispensing with divers. In the fall of 1948, a converted minesweeper was equipped with a 1,000-lb dart, handled mechanically in a tilting cradle mounted overside. This was the first vessel to be outfitted specifically for submarine coring. Although experiments were performed on many types of jetting devices, it was found that a simple jet tool with projecting core barrel provided an accurate and fool-proof method of taking oriented and unoriented cores in areas where the subsea formation was buried under as much as 200 to 250 ft of overburden. Attempts to extend the range of the jetting method resulted in reaching depths up to 500 ft beneath the sea floor; however, at this depth the method is not commercially feasible.
As the need for deeper geological information became urgent, rotary drilling was introduced to offshore exploratory work in 1950. The first rotary unit utilized a seismic drill-type electrically driven rotary table mounted overside in a carriage having a fore and aft axis to compensate for roll of the vessel. In 1953 this unit was removed and replaced with a rotary having a double jack-knife mast with draw-works and rotary table patterned after conventional truck-mounted land rigs. By 1955 drilling vessels were being outfitted which permitted drilling through a caisson located near the center of the ship. These vessels were designed for drilling to about 7,500 ft and at least one ex-Navy barge has been modified to permit drilling to depths of about 10,000 ft (see Table 1).
In-Situ Leaching of South Texas Uranium Ores—Part 2: Oxidative Removal of Adsorbed Ammonium Ions With Sodium Hypochlorite
Authors: Paul J. M. , Johnson W. F. , Fletcher A. , VenutO P. B. 
Published: December 2007

Abstract
This paper reports a laboratory study of the oxidative destruction by sodium hypochlorite (NaOCl) of ammonium ions adsorbed on relatively reduced south Texas uranium ore. Included are an assessment of reaction stoichiometry, determination of some major reaction pathways and side reactions, and identification of several intermediates. Adsorbed ammonium ions were completely removed by 0.5% NaOCl, with the concentration of NH3 in the effluent falling to a very low value after 10 to 15 PV NaOCl oxidant. A small fraction (5 to 10%) of NaOCl was utilized in reacting with NH3. After the NH3 was nearly depleted, mono-, di-, and trichloramines, the expected intermediates in NaOCl oxidation of NH3, were observed. Chloramine decomposition studies showed that all three decomposed completely within 12 days. Since the ore was relatively highly reducing, the major part of the NaOCl was, not unexpectedly, consumed in side reactions. Substantial quantities of sulfate, reflecting oxidation of sulfide minerals such as pyrite, were formed, large amounts of uranium were leached out, and substantial amounts of calcium and magnesium ions were also produced during the presaturation with NH4HCO3 preceding the oxidation stage.
Volumetric Requirements for Foam and Mist Drilling Operations
Authors: Okpobiri Godwin A. , Ikoku Chi U. 
Published: December 2007

Summary
State-of-the-art foam and mist drilling suggests a need for predictive models for volumetric requirements that properly account for frictional losses caused by the solid phase in solids/foam slurry flow, settling velocities of such solids, and pressure drop across bit nozzles during foam flow. The objective of this paper is to fulfill this need.
A model that predicts pressure drop across bit nozzles for foam and mist is presented. It accounts for the compressibility of foam but assumes negligible pressure losses resulting from friction and change in elevation.
A model has been developed for predicting minimum volumetric requirements for foam and mist drilling operations. It accounts for the frictional losses caused by the solid phase, pressure drop across bit nozzles, and particle-settling velocity. The technique offers a high degree of flexibility in the selection of wellhead injection pressures and volumetric injection rates.
Field application of this work can be accomplished by two primarily graphical methods that depend on compressor specifications: variable-backpressure and constant-backpressure schedules. Charts are presented for 7.875- and 9.00-in. [20.0- and 22.9-cm] hole sizes, and for 0.500-, 0.75-, and 1.00-in. [1.27-, 1.91-, and 2.54-cm] cutting sizes. Penetration rates range from 30 to 90 ft/hr [9 to 27 m/h].
Results indicate that volumetric requirements increase with increasing hole size, depth, and particle size. Increases in penetration rate cause only minor increases in volumetric requirements. All foam-drilling and well-cleanout operations can be accomplished within the laminar flow region with adherence to 0.55 minimum bottomhole and 0.96 maximum annular foam quality. Annular backpressures greater than atmospheric pressure are needed to maintain a bottomhole foam quality of 0.55 or more while reaching reasonable depths. To maintain constant depth as backpressure increases, however, both wellhead injection pressure and gas injection rate must be increased, and liquid flow rate decreased.
Surfactant and Polymer Losses During Flow Through Porous Media
Authors: Friedmann François 
Published: December 2007

Summary
Experimental methods are presented to evaluate and to measure the major contributions to surfactant and polymer losses in Berea sandstone for various oil saturations (no oil to postwaterflood residual oil). The results of linear displacement experiments are shown, and chemical losses evaluated for various sequences of injected fluids. Surfactant and polymer losses are evaluated independently, then for simultaneous injection into the core. When oil is present, chemical losses are related to phase behavior properties with salinity requirement diagrams.1 Both a synthetic white oil and a reservoir stock-tank crude oil are used in the experiments.
A Comparison of Calculated krg/kro Ratios With a Correlation of Field Data
Authors: Torcaso Michael A. , Wyllie M.R.J. 
Published: December 2007

Abstract
It is shown that krg/kro ratios computed on the assumption that the average sandstone reservoir has a poresize distribution characterized by a linear 1/Pc2 saturation plot are in good agreement with corresponding krg/kro ratios obtained by Wahl, Mullins and Elfrink by the correlation of field measurements.

Equation for Calculating krg/kro Ratios
Methods of calculating relative permeability data have recently been reviewed and extended. It was shown that for sandstone reservoirs where 1/Pc2 is approximately a linear function of effective saturation (as suggested first by Corey) it is possible to express relative permeabilities in very simple terms. For systems wetted by connate water and producing oil and gas (gas saturation growing at the expense of oil) the expression for the krg/kro ratio is
....................(1)
The accuracy of Eq. 1 has been frequently confirmed in our laboratories; because of its simplicity we make routine use of it in the analytical solution of problems in reservoir engineering. Nevertheless, comparisons of the krg/kro ratios yielded by Eq. 1 with appropriate reservoir data have been few. The publication by Wahl, Mullins and Elfrink of an empirical equation for krg/kro ratios is thus of interest since this equation is specifically stated to be based on the correlation of field measurements made on sandstone reservoirs.
Fracturing Fluids: Fluid-Loss Measurements Under Dynamic Conditions
Authors: Roodhart L. P. 
Published: December 2007

Abstract
When filter-cake-building additives are used in fracturing fluids, the commonly applied static, 30-minute API filtration test is unsatisfactory, because in a dynamic situation (like fracturing) the formation of a thick filter cake will be inhibited by the shearing forces of the fracturing fluid. A dynamic, filter-cake-controlled, leakoff coefficient that is dependent on the shear rate and shear stress at the fracture face is, therefore, introduced. A test apparatus has been constructed in which the fluid leakoff is measured under conditions of temperature, rate of shear, duration of shear, and fluid-flow pattern as encountered under fracturing conditions. The effects of rock permeability, shear rate, and differential pressure on the dynamic leakoff coefficient are presented for various, commonly used fracturing-fluid/fluid-loss-additive combinations.
Economics and Finance -The Roots of Corporate Enterprise
Authors: Parker Charles F. 
Published: December 2007

What Factors Does Management Consider Before Spending? Where Do Corporations Obtain Their Capital?

Abstract
Corporate economics and finance is by no means a single subject; in fact, it's a whole "barrelful" of them. This paper concerns some of the broader aspects of just two of these subjects. (1) Where does a corporation get its capital? and (2) how does it determine the best way to employ its capital?
It has often been said, "money is the root of all evil." Personally, I don't believe this is true. But it is certainly true that money is the root of all corporate enterprise. A corporation must have it to be born and must use it wisely to stay alive.

Introduction
In corporate finance there are, broadly, two kinds of money, yours and someone else's.
"Your money" is the equity money, the capital invested in the business by the owners when they purchase and retain capital stock. A shareholder owns a fraction of the business and of its profits, and he shares in the risks. His income and the value of his shares vary with the success of the corporation. As a common shareowner he also shares the responsibility for control of the business.
Not all earnings are distributed to the share owners. Usually, a part of earnings is retained by the company and reinvested in the business. These retained earnings, occasionally referred to on the balance sheet as capital surplus, constitute additional equity money. This money also belongs to the share owner and the value of his shares increases as capital surplus accumulates.

How Corporations Are Financed
"Other people's" money may be obtained by borrowing. It can be borrowed directly from banks or other institutions (or from individuals). Bank loans are usually for relatively short terms, five years or less. Or a borrower may obtain money by issuing bonds. The bondholder then becomes a creditor and, as such, has no direct voice in the business. He merely holds a promise that he will be paid a fixed amount of interest each year plus principal by a predetermined maturity date.
Mortgage Bonds and Debentures are Secure Investments
There are broadly two kinds of bonds, the mortgage bond and the debenture.
Effect of Bit Hydraulic Horsepower on the Drilling Rate of a Polycrystalline Diamond Compact Bit
Authors: Holster Jesse L. , Kipp Robert J. 
Published: December 2007

Summary
A laboratory drilling program was conducted to measure the effect of bit hydraulic horsepower on the drilling rate obtained with a polycrystalline diamond compact (PDC) bit. Drilling tests were conducted under simulated downhole conditions with an 8 1/2-in. [21.59-cm] diameter PDC bit fitted with four sets of five equal-sized nozzles. PDC bit fitted with four sets of five equal-sized nozzles. Mancos shale, Pierre shale, and Berea sandstone were drilled with both water- and oil-based drilling fluids to determine the interactions among bit hydraulics, rock characteristics, and the drilling fluid. For the range of drilling conditions and rocks examined, the results indicated that bit hydraulic horsepower had a significant influence on the drilling rate. The degree to which drilling rate was affected by bit hydraulic horsepower was dependent on the rock/drilling-fluid combination.

Introduction
Proper hydraulic design for effective cleaning and Proper hydraulic design for effective cleaning and cooling of PDC bits has been recognized as a major factor in their successful application since these bits were introduced. Historically, there have been two approaches to the hydraulic design of PDC bits:natural diamond-bit flow-distribution systems (water courses with large total flow areas) andhigh-velocity jet nozzles.
Both types have been used with varying degrees of success but often for unrecognized reasons. The water-course-type hydraulic designs were characteristic of most early matrix-bodied PDC bits. Nozzled bits evolved from the steel-bodied bits with stud-mounted cutters, although matrix-bodied bits are now available with jet nozzles. An increasing number of commercial PDC bits are becoming available with interchangeable nozzles, providing the flexibility of rig-site hydraulics optimization, providing the flexibility of rig-site hydraulics optimization, With these interchangeable nozzles, the hydraulic energy (or power) of the drilling fluid that is dissipated across the bit face can be adjusted to match that portion of the rig's hydraulic power that is available for the bit after other system losses have been considered. Unfortunately, the benefit in increased drilling rate that can be expected by an optimization of bit hydraulic horsepower has yet to be adequately defined quantitatively for PDC bits. The objective of our work was to determine experimentally the effect of bit hydraulic horsepower on the drilling rate achieved with a jet-nozzled PDC bit while three rock types were drilled with both oil- and water-based drilling fluids.
PDC Bit Hydraulics-Background PDC Bit Hydraulics-
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Field Application of Diamond-Bit Hydraulic-Lift Principles
Authors: Winters Warren J. , Warren T. M. 
Published: December 2007

Summary
Hydraulic lift can have a major effect on the operation of diamond drill bits. The actual weight on bit (WOB) is less than the measured weight by the amount of hydraulic lift, or pumpoff force, acting beneath the bit. Pumpoff forces in excess of 15,000 lbf [67 kNJ have been recorded.
Historically, the hydraulic-lift effect has been recognized but not understood well enough to be accounted for reliably. Failure to account for hydraulic lift can adversely affect actual bit performance and interpretation of the results. It is now possible to determine hydraulic lift reliably with the practical techniques presented here.
Field tests show that pumpoff force tends to double as the bit dulls. Appropriate WOB adjustments, determined through pumpoff tests run on the rig, are required to maintain bit performance. The applications to diamond bits run on mud motors are particularly advantageous.
Rheological Characterization of Fracturing Fluids by Using Laser Anemometry
Authors: Guillot Dominique , Dunand Alain 
Published: December 2007

AbstractIn this paper we describe the use of a novel technique, laser Doppler anemometry (LDA), to obtain information on fracturing fluid behavior. This technique permits measurement of fluid velocity at any point in a flow system. By scanning across the flow geometry, it is possible to obtain the velocity profile, which is related, in turn, to the rheology of the fluid.At low shear rates, velocity profiles obtained for aqueous solutions of hydroxypropyl guar showed significant deviations from those calculated using known power law parameters. The investigation was extended by conducting a series of rheological experiments using rotational and capillary viscometers over a wide shear-rate range (10−2 to 2 × l03 seconds−1). The data have been fitted to a three-parameter Ellis model, and the velocity profiles calculated from these data agree well with experimental ones.The immediate results of this work are of interest in proppant transport modeling and correlate well with published data that show that apparent viscosities obtained from proppant settling velocities are lower than those obtained from power law parameters.
An Analytical Extension of the Dykstra-Parsons Vertical Stratification Discrete Solution to a Continuous, Real-Time Basis
Authors: Reznik A. A. , Enick Robert M. , Panvelker Sudhir B. 
Published: December 2007

Abstract
Analytically exact and continuous solutions are developed for the space-time relationships of a linear waterflood in a vertically stratified reservoir model. The solutions represent simple extensions of the analytical, but discrete, spatial relationships of Dykstra and Parsons to analytically continuous expressions. Explicit solutions for time are presented that permit the coupling of all instantaneous and cumulative performance parameters to a completely rational time basis.
The continuous nature of the solutions permits unusual fluid behavior to be observed between successive bed breakthrough points. Although the model assumes pistonlike displacement, these novel phenomena do not appear to be artifacts of this limiting assumption.
This work develops the concept of a bed property time that forms the basis for a generalized bed-ordering parameter. For the case of constant injection pressure, property time is shown to be identical to the real or process time. For the common case of constant overall injection rate, the customary use of property time concepts to determine real or process time is shown to be completely erroneous, yielding values that are incorrect both in magnitude and in trend.
A bed flood-front passing phenomenon is presented that allows the flood fronts of "slower" beds initially to lead those of "faster" beds if specified constraints are satisfied. It is shown that these constraints can be satisfied for moderate bed-fluid property variations.
The analytical nature of the solutions provides greater insight into the controlling factors of such processes. The use of real time as a process parameter provides a more realistic basis for comparative performance between floods under the same or different injection conditions. The relationship between injected PV and time can be used to extend the linear model to approximate predictions for stratified, nonlinear, pattern floods.