bluuebunny/crossref_metadata_2025_split huggingface dataset:
Casing Wear During Drilling: Simulation, Prediction, and Control
Authors: Schoenmakers J. M. 
Published: December 2007

Summary
Four case studies show that laboratory simulations of casing wear caused by rotating tooljoint hardfacings correspond very well to field-measured casing wear. Moreover, the work reveals concentrations of casing wear at the kickoff point of a deviated well and near casing collars. Drillpipe/casing protectors do not always appear effective in avoiding casing wear. It is concluded that prediction of casing wear is possible with laboratory simulations, and that casing wear can be controlled by sufficiently smooth hardfacings, weighted mud, and moderate tooljoint/casing contact forces. An inspection technique can be used to qualify hardfacings for use in casing. Hardfacings that are machined to meet the smoothness requirement are commercially available.
Predicting Bottomhole Assembly Performance
Authors: Williamson J. S. , Lubinski A. 
Published: December 2007

Summary
A computer program for prediction of bottomhole assembly (BHA) performance has been developed. Input parameters include formation dip angle, hole and collar size, and stabilizer spacing. The predictions are in drilling terms: hole curvature, hole angle, weight on bit (WOB), etc. Results of extensive parametric studies and field use are presented.
Downhole Control of Deviation With Steerable Straight-Hole Turbodrills
Authors: Gaynor T. M. 
Published: December 2007

Summary
Advances in directional drilling have until recently been confined to issues that are peripheral to the central problem of controlling assembly behavior downhole. Examples of these advances are measurement while drilling (MWD) and the increasing use of computer assistance in well planning. These were significant steps forward, but the major problem remained. Changes in formation deviation tendencies led to trips to change bottomhole assemblies (BHA's) to cope with the new conditions. There is almost no direct control of deviation behavior.
The steerable straight-hole turbodrill (SST) addresses this problem directly, allowing alteration of the well course without the need to trip. The availability of such a system radically changes the way in which directional well planning may be approached. This paper describes the equipment used and the equipment's construction and operational requirements. It discusses the capabilities and current limitation of the systems. Field results are presented for some 300,000 ft [91 500 m] of deviated drilling carried out over 2 years in Alaska and the North Sea. A series of four highly deviated wells totaling 35,000 ft [10 700 m] with only three deviation trips is included.
The SST is the first deviation drilling system to achieve deviation control over long sections without tripping to change BHA's. Bits and downhole equipment are now more reliable and long-lived than ever; therefore, deviation trips are becoming a major target for well cost saving.
Computer Processing Improves Hydraulics Optimization with New Methods
Authors: Gavignet A. A. , Wick C. J. 
Published: December 2007

Summary
In current practice, pressure drops in the mud circulating system and the settling velocity of cuttings are calculated with simple rheological models and simple equations. Wellsite computers now allow more sophistication in drilling computations. In this paper, experimental results on the settling velocity of spheres in drilling fluids are reported, along with rheograms done over a wide range of shear rates. The flow curves are fitted to polynomials and general methods are developed to predict friction losses and settling velocities as functions of the polynomial coefficients. These methods were incorporated in a software package that can handle any rig configuration system, including riser booster. Graphic displays show the effect of each parameter on the performance of the circulating system.
Unique Marine Craft Moves Rigs with Speed and Economy at Lake Maracaibo
Authors: Kunzi Robert E. 
Published: December 2007

Abstract
During the past three years, Creole Petroleum Corp. has used a highly specialized marine craft to move unitized drilling rigs in its Lake Maracaibo, Venezuela, oilfield operations. This paper describes the development, construction, operation and economics of Creole's "floating fork-lift". The marine rigmover has proven to be a practical and economical device, and it could be used in any large-scale oilfield development program in deep inland or sheltered ocean waters.

Introduction
The great majority of Creole Petroleum's concessions in Western Venezuela lie beneath the waters of the northeast quadrant of Lake Maracaibo. Lake Maracaibo is a large, pear-shaped, fresh-water lake about 100-miles long and 60-mile wide with a maximum water depth of 125 ft and an over-all average depth of about 40 ft. All of the company's lake wells have been drilled from permanent, concrete-pile platforms. These platforms support the rig substructure, a standard-type derrick, the draw-works and the drill string. Lateral-sway bracing is the only connection between the casing strings and the well platform. Mud pumps, pipe racks, auxiliary equipment and materials storage are located on an anchored barge-tender. Almost all of Creole's earlier wells in the lake were equipped with a standard derrick which was left in place on completion of the well in order to be utilized in future repair jobs. It was felt that the capital outlay for many derricks was less than the expense required to erect and dismantle a derrick for each repair job during the life of a well. In 1955, Creole's management authorized a study of the derrick and rig-moving problem to determine if there was a faster, more economical method of handling the job. Creole's goal was to replace the old method of rig moving-that is, piece-meal movement of the rig-with a more efficient unitized method. This goal was attained in the development of a "U"- shaped, self-propelled craft which can maneuver around the well platform, pick up the rig-derrick package, move to the next location, and then place the unit on the new foundation (see Figs. 1 and 1A). Even though over one and three-quarter million dollars have been invested in the rigmover and its associated substructures, the savings realized through the use of this equipment paid out the investment in Nov., 1961.

Development History
As early as 1951, Creole was making over-water rig moves similar in principle to those made by the rigmover. The original "straddle barges" unit was designed for use in the Pedernales field, located in the tidal channel area of the Orinoco river delta in Eastern Venezuela. It consisted of two barges supporting a one-piece substructure complete with draw-works, engines and derrick. The drilling unit was placed by straddling the new pile foundation with the two barges and then lowering the rig by controlled flooding of the barges. The moves were also timed to take advantage of the tidal differences in water level. Mud pumps and pipe racks were aboard a barge tender.
JPT
P. 228^
Soluble Fluid-Loss Additives Can Reduce Well Productivities and Prevent Complete Gravel Placement
Authors: Sparlin D. D. , Hagen R. W. 
Published: December 2007

Summary
Fluid-loss additives are frequently used in completion fluids and pills to reduce fluid costs and formation damage, but many of these additives create more damage than they prevent. Common recommendations are to use fluid-loss additives that will be dissolved by the produced fluids, acid, or water so that they may be readily removed after a job. Typical additives are oil-soluble resins, calcium carbonate particles, and salt suspensions.
It is particularly important that soluble additives be used for wells that are to be gravel packed because the gravel will trap insoluble solids in the well. Evidence indicates, however, that even these soluble products remain in perforation tunnels and impair productivities of wells. Examples of wells indicating this effect during post-gravel-pack acid treatments are discussed. The theory of why this occurs and calculations of pressure drops through perforations filled with fluid-loss additives are presented.
It has also been found that excess fluid-loss additives prevent complete coverage of a zone with gravel, because of either inadequate leakoff to the formation or partial plugging of the screen. Therefore, it is imperative that these additives be removed by acid, water, or solvents preceding the gravel slurry; however, if their removal causes loss of circulation, the results may be equally bad.
The most practical solution to this problem is to use a combination of gravel and viscous fluids as a diverting system for the fluids that will remove the additives without creating additional formation damage. When this system is used just ahead of a gravel slurry, it not only helps remove the fluid-loss additives, but also helps prevent excessive fluid losses and partially prepacks the formation with gravel.
Core Cleaning for Restoration of Native Wettability
Authors: Gant Preston L. , Anderson William G. 
Published: December 2007

Summary
Certain additives used in drilling and completion fluids may alter the wettability of core. For example, the surfactants in invert-oil-emulsion drilling muds are known to alter the wettability of core. Because routine cleaning methods do not remove these surfactants, core that is to be used for special laboratory analyses, such as relative permeability, capillary pressure, and saturation exponent, is left with an altered wettability. Experiments with such core will obviously produce erroneous data. To obtain reliable results, cleaning methods must be developed to remove these surfactants, allowing restoration of plugs to their natural wettability. Once the core is cleaned, the wettability of the cleaned core can be restored by saturating with synthetic formation brine and uncontaminated reservoir crude, then aging at the reservoir temperature.
This report ranks the efficiency of solvents in removing surfactants from plugs contaminated with invert-oil-emulsion drillingmud filtrate. Eight solvents for Berea sandstone and seven solvents for Guelph dolomite have been ranked after Dean-Stark extraction of mud surfactants using the U.S. Bureau of Mines (USBM) wettability index. The best solvent for both rock types was a 50/50 mixture of toluene/methanol, or the equivalent, containing 1% ammonium hydroxide. Toluene, the most commonly used solvent for core cleaning, was one of the poorest solvents tested. The solvents that are effective in removing surfactants can be used to clean contaminated core.
The Concept of Relative Ganglion Velocity and Generalization to Oil-Bank Movements in Porous Media
Authors: Egbogah Emmanuel O. 
Published: December 2007

Summary
This paper discusses a simple computational technique for determining relative ganglion velocity in a pore and its implication to the formation and propagation of an oil bank. The approach is based on a simple theory of the movement of a discontinuous oil droplet (ganglion) through a model pore. The analysis, based on a simplified conical geometric model, permits the development of expressions for relative ganglion velocity (velocity of the oil ganglion relative to the bulk liquid velocity) under various flow conditions. This parameter is essential for modeling waterflooding and/or EOR processes and facilitates the prediction of oil-bank movements. An example calculation illustrates the application of the concept. Results of the calculations indicate that faster oil-bank movements are attained when interfacial tensions (IFT's) are low and pressure gradients are high.
A Correction for the Effect of Comminution on the Cation Exchange Capacity of Clay-Poor Sandstones
Authors: Huff G. F. 
Published: December 2007

Summary
It is well known that comminution (decrease of particle size by grinding) can increase the cation exchange capacity (CEC) of geologic materials. Because comminution is often a "first step" in sample preparation, it is desirable to be able to correct for comminution-induced effects.
The relative increase in CEC of poorly lithified clay-poor sandstones and better-lithified shaly sandstones from Caño Limon Well 3 and La Yuca Well 6, Llanos basin, Colombia, correlated well (r≥0.97) with the square root of the duration of sample comminution. A method based on this correlation has been developed to correct for comminution-induced increases in the CEC of poorly lithified clay-poor sandstones. The method was also applied to the better-lithified shaly sandstones with good results.
The rate of relative increase of the CEC with comminution showed an inverse correlation with the total weight percent clay in a specimen. This suggested that much of the increase of the CEC of the specimen was caused by an increase in the CEC of quartz, which was the dominant mineral in these rocks.
Resolving Pore-Space Characteristics by Rate-Controlled Porosimetry
Authors: Yuan H. H. , Swanson B. F. 
Published: December 2007

SummaryBy monitoring the mercury capillary pressure in rate-controlled porosimetry (intrusion) experiments, new information regarding the pore space of a rock sample has been obtained. With this technique, called an apparatus for pore examination (APEX), it is now possible to resolve the pore space of a rock sample into two interconnected parts. One part identifies the individual pore systems (pore bodies), which are low-energy sumps or regions of low capillarity. The other part corresponds to the pore throats that interconnect with pore systems.New capillary-pressure curves have been obtained by partitioning the total capillary-pressure curve (normal capillary-pressure curve) into two subcurves: the subison capillary-pressure curve, which details the distribution of pore bodies, and the rison capillary-pressure curve, which details the distribution of pore throats. We present APEX data on Berea sandstone and San Andres dolomite that show the volume distribution of low-capillarity regions within the pore space of these rocks. These regions of low capillarity are the principal pore-space regions that trap the residual nonwetting phase upon imbibition of a strongly wetting fluid, as measured by toluene/air systems. The residual nonwetting-phase saturations as determined by the APEX method and by the toluene/air method are in excellent agreement. Thus, the detailed volume distribution of pore systems responsible for trapped nonwetting-phase saturation is determined from APEX measurements, which can have important implications for EOR.
Mechanistic Study of Gravity-Assisted CO2 Flooding
Authors: Tiffin D. L. , Kremesec V. J. 
Published: December 2007

Summary
A series of gravity-assisted vertical core displacements of contact-miscible and multiple-contact-miscible CO2/recombined-crude-oil systems was conducted and simulated. Gravity-assisted displacements offer the advantages of eliminating gravity tongues and stabilizing viscous fingers. Although the process has been used successfully in the field, a mechanistic laboratory and modeling study of gravity-assisted multiple-contact-miscible CO2 flooding has not been described previously.
The results from this experimental and computer modeling study elucidate the complex mechanisms acting in gravity-assisted CO2 flooding. Component transfer, as occurs in multiple-contact-miscible processes, can strongly affect flood-front stability. In general, better performance is obtained from vertically downward displacements than from comparable displacements in horizontal cores. Miscibility develops at the same pressure in vertical floods and in a much shorter core length. It was further demonstrated that displacement efficiency increases at conditions where mixing of CO2 and oil is minimized. Excellent simulation of experimental recoveries and rates were obtained with a compositional simulator in a one-dimensional (1D) mode.
Diffusion of CO2 at Reservoir Conditions: Models and Measurements
Authors: Grogan A. T. , Pinczewski V. W. , Ruskauff Gregory J. , Orr F. M. 
Published: December 2007

Summary
Mathematical models are developed to describe the transport of dissolved CO2 in a liquid phase, and results of measurements of the diffusivity of CO2 in hydrocarbons and water at reservoir conditions are reported. The measurements were made with novel techniques based on the direct observation of the motion of an interface caused by the diffusion of CO2 through oil or oil shielded by water. Diffusion coefficients were determined by fitting the mathematical models to the observed motion of the interfaces. This method allows the measurement of diffusion coefficients without the need to determine phase compositions and is therefore suited to measurements at elevated pressures (reservoir conditions). Measured diffusion coefficients are reported for CO2 in pentane, decane, and hexadecane at 25°C [77°F] and pressures up to 6000 kPa [870 psia]). Limited measurements of CO2 diffusion in Maljamar crude oil are also described. In addition, results of measurements for the diffusion of CO2 in water are presented. These are the first such measurements at high pressures (up to 6000 kPa [870 psia]). Correlations of diffusion coefficients in liquids at atmospheric pressure are shown to give reasonable estimates of diffusion coefficients for CO2 in fluids at reservoir conditions. Finally, the measured diffusion coefficients and mathematical models are used to assess the impact of diffusive mixing on CO2 floods at various length scales to examine the relationship between laboratory-scale corefloods and field-scale displacements.
Hydrolytic Stability of Alkylethoxy Sulfates
Authors: Talley Larry D. 
Published: December 2007

Summary
Sulfate surfactants are being proposed by industry for use in moderate-temperature surfactant floods. Sulfates are also being considered by some groups for use in CO2 mobility control and surfactant/alkaline floods. Data from this study show that the maximum applicable temperatures for sulfates under these pH conditions are much lower than for neutral pH conditions. Rate equations are derived from Arrhenius data on the basis of observed decomposition mechanisms. The equations are used to calculate surfactant lifetimes and maximum temperature limits at various reservoir conditions. The maximum temperatures and lifetimes are functions of pH and brine composition.
The Use of Semicontinuous Description To Model the C7+ Fraction in Equation of State Calculations
Authors: Behrens R. A. , Sandler S. I. 
Published: December 2007

Summary
A semicontinuous thermodynamic description has been used to model the C7+ fraction for equation of state (EOS) calculations. This semicontinuous description may be used in existing discrete-component EOS programs by picking pseudocomponents in a rigorous a priori fashion dependent only on the properties of the C7+ fraction. Excellent representation of experimental PVT data considered here is obtained with only two C7+ pseudocomponents, although the theory and procedure extend to three or more components.
The New Frontier
Authors: Pyle Howard C. 
Published: December 2007

Americans were born of a revolution. We are the custodians of a tradition and a practice of liberation and of freedom. We have never lost our proud independence and individuality, and we never will. We can take care of ourselves and our families and we know it. Traditionally, when we felt confined and became restless, we moved farther west. There had always been a frontier out there and a new way of life. Where do the young men of today go with their strong independence and eager self-reliance? Their interest and ours must become the whole world. Our frontier is broadened; it is everywhere.

U. S. Leads Free World in Peace
Two world wars and the constant threat of a third one makes us ever conscious of our neighbors. World-circling satellites draw all countries closer together. The wealth and industrial might of the United States has resolutely placed us in the position of world leadership. This is the new frontier; leadership in a free world at peace.
America has become great because on one basic philosophic idea - the idea that we can improve the lot of our people without interfering with their civil liberties. We recognize the essential dignity of man. Needless to say, there are opposing ideas in the world today, ideas that the individual exists for the sake of society and the state alone. We know that our awareness of the individual importance of man is right, and we must demonstrate to others that this is true. To accomplish this, we must all increase our social obligations. This is a practical reaction to the now basic fact, which becomes more insistent every day, that no public or private purpose can be sensibly considered apart from world affairs.
The world is faced with enormous possibilities of growth. Man is at last breaking with the past. Our problems are not only greater, they are new. The limitations and safeguards our forefathers counted on are gone. We can not hide. We can no more ignore the threat posed by atomic or thermonuclear warfare than we can a recession or inflation. These threats are not simply scientific or government problems, they are our problems, yours and mine. They will not disappear by just being ignored, and they will not be resolved by using old rules of thumb.
We should all help form world opinion, both as individuals and as a free and enterprising nation. As engineers and professional men we should be particularly active, and we must be heard from. With our new United Engineering Center we are becoming a neighbor to United Nations. What better reason could we have for becoming more conscious of world activities, followed by becoming participants in world affairs?
Flow Visualization of the Effects of Interfacial Tension on Displacement
Authors: Hornof V. , Morrow N. R. 
Published: December 2007

Summary
The effects of interfacial tension (IFT) on displacement behavior have been investigated through flow visualization experiments in porous media formed by thin layers of sintered glass beads. Fluid densities and viscosities were matched to avoid viscous and gravitational instabilities. Displacements were carried out with aqueous/oleic liquid pairs, which gave IFT’s of 17.0, 1.2, 0.029, and 0.002 dynes/cm [17.0, 1.2, 0.029, and 0.002 mN/m]. Results show how IFT, wettability, and model heterogeneity interact to determine the shape and stability of the displacement front.
Surfactants for EOR: Olefin Sulfonate Behavior at High Temperature and Hardness
Authors: Bavière Marc , Bazin Bridgltte , Noïk Christine 
Published: December 2007

Summary
The surfactant properties usually required for EOR are investigated with alpha-olefin sulfonates (AOS’s), particularly at high temperature, salinity, and hardness, together with their solubility in brine, chemical stability, phase behavior, and adsorption.
The use of a cosolvent enables aqueous solutions to be prepared with concentrated brine, even at high divalent cation levels. But the chemical stability of some solutions can be affected by their sensitivity to the oxidation of unsaturated components, resulting in a decrease of the pH. Precautionary measures to stabilize the solutions are stressed–i.e., anaerobic environment, maintenance of an alkaline pH, or addition of alcohol. As already shown, these surfactants provide low interfacial tensions (IFT’s) and high solubilization parameters at high salinity and divalent cation content. Properties of optimal formulations have been investigated as a function of surfactant and cosolvent molecular weight and brine composition.
Adsorption data on Na− and Ca− kaolinite are presented. In NaCl solutions, the amount of sulfonate adsorbed increases slightly with salinity. Preliminary measurements in hard water are shown to bring out the specific effect of calcium ions. According to the results concerning properties validly considered as screening criteria, we conclude that this family of sulfonates appears to be a potential candidate for EOR.