bluuebunny/crossref_metadata_2025_split huggingface dataset:
Slim-Tube Investigation of CO2 Foams
Authors: Irani C. A. , Solomon C. 
Published: December 2007

ABSTRACT
Formation and propagation of foams at considerable distance from the injection point is not well understood. In this study a 100-ft slim tube packed with 50/70 Ottawa sand was used to investigate foam behavior over long distances at reservoir temperatures and pressures. Both simultaneous and alternate modes for surfactant and CO2 injection were found to be inadequate. The liquid surfactant phase has a much lower linear velocity in the formation relative to the gas phase, and consequently there is a steady buildup of surfactant concentration in the vicinity of the injection point. Additionally, foams were found not to propagate, but rather to form spontaneously where CO2 and surfactant contact each other. As a result, in either the simultaneous or alternate injection modes, the foam front was found to have a very low frontal velocity, while unnecessarily high pressure drops were generated behind the foam front.
An alternate approach referred to as the dual slug injection method is proposed. This method calls for injecting all the necessary surfactant as a single, large, dilute slug and then chasing it with CO2. This approach demonstrated almost plug-like displacement of the foam front through the slim tube, resulted in optimum use of the surfactant and maximized foam penetration. For some surfactants the presence of crude oil is detrimental to foaming action and oil recovery is hampered. Additional testing of this methodology is necessary in order to verify the improved efficiency of this approach relative to conventional injection schemes.
Anadarko Basin Completion Overview
Authors: Clement C. C. , Maness S. F. , Mason C. M. 
Published: December 2007

Abstract
Completion methods used in the deep Anadarko Basin have varied a great deal over the past several years.
Due to an active exploration program in the basin, Sohio Petroleum Co. formed a Springer task force group to evaluate past methods and to develop and refine deep completion techniques in the Morrow and Springer formations. This group formulated guidelines based upon published literature and past experience of the group members.
The guidelines were implemented in the field and modified as more data and knowledge were obtained, resulting in a specific set of guidelines now used on all Morrow and Springer completions.
There are a number of case histories that illustrate the evolution and reasons behind the specific guidelines, which will be listed.
Using Fiberglass Sucker Rods in Deep Wells
Authors: Hicks A. W. 
Published: December 2007

Abstract
When a flowing well no longer produces adequate volumes of oil, it is wise to use the most economical method of artificial lift to produce the wellbore fluids. When all forms of artificial lift are considered and the cost of producing oil exceeds the value of the produced oil, it becomes uneconomical to operate the well and the well is usually plugged and abandoned. Beam pumping systems utilizing fiberglass sucker rods are producing oil from wells that had previously been uneconomical and are now profitable operations. Beam pumping systems using fiberglass sucker rods in deep wells are producing fluid more economically than systems using steel sucker rods.
In contrast to standard steel sucker rods where relatively heavy weight and corrosion are inherent, fiberglass sucker rod bodies are much lighter in weight and are not susceptible to corrosion.
The author presents this paper in an effort to provide an in-depth study using fiberglass sucker rods in deep wells. Consideration is given to rod string design, pumping unit design, energy consumption, and production capability.
This paper will present conclusions from studies of beam pumped wells with seating nipple depths in excess of 11,000 feet. The overall results have meant a considerable increase in production while reducing working stress on surface and sub-surface equipment.
In conclusion, fiberglass sucker rod strings, when properly designed, reduce peak polished rod loads, torque requirements and energy consumption.
Saving Money: The Real Aim of Quality Assurance Systems
Authors: Gookin L. E. 
Published: December 2007

Abstract
Deep drilling requires detailed planning, procurement, and operations over a relatively long time span as compared to normal well operations. However, like all drilling ventures, the ultimate goal of a deep oil or gas well is to make a profitable well as cheaply as possible. Consequently, a quality system that assures efficient activities and cost effective methods is required to optimize this goal. This paper presents the basis of a Quality Assurance System which can be established to improve efficiency and reduce costs.
Numerical Analysis of Helical Buckling
Authors: Mitchell Robert F. 
Published: December 2007

Abstract
The equilibrium equations for a helically buckled tubing with weight are solved by an approximate method that produces a generalized form of Lubinski's force-pitch relationship. This new solution provides a method for evaluating the range of application of Lubinski's results. A new definition of the neutral point is derived based on a contact force criterion. A numerical analysis of a cantilever end constraint at the packer is used to evaluate the generalized buckling solution. This analysis puts the Lubinski solution in a technical context that allows further developments, such as tapered strings, inclined wellbores, and friction.
Automatic Density Control System Improves Cement Slurry Performance
Authors: Edgley K. D. 
Published: December 2007

Abstract
Correlation of anticipated and actual cement slurry performance has been improved by combining microprocessor-based density control with a recirculating cement mixer. After desired density is set from a membrane keypad, the system's electrically and pneumatically operated controls keep the slurry density within ±.1 lb/gal of selected density. Density setpoint may be changed during the job.
The density of cement slurry as mixed on the surface is critical to the ultimate performance of the slurry downhole. In deep, hot holes, density control is especially critical, and the need for dependable performance is intensified. Accuracy of the automated system exceeds human capabilities to maintain slurry density throughout an entire cement job.
Subject paper presents operating description and specifications of the system, including schematic diagrams. The manual backup system is described.
Density control documentation from actual cement jobs is presented.
Minimizing Reservoir Damage by Insuring Proper Additive Performance in Stimulation Fluids
Authors: Holcomb D. L. 
Published: December 2007

Abstract
Specific aspects of reservoir damage, particularly associated with clays are well defined but are seldom considered in total with respect to loss of additive effectiveness due to possible negative reactions in a clay environment.
Significant losses of additives and subsequent additive effectiveness are suggested and documented with emphasis on various clay control methods in the presence of various key clay families.
Tendencies for additive incompatibilities in various clay and fines environments within sensitive reservoirs will be outlined. Various methods to prevent damage when using these additives will be discussed including overcoming loss of performance in situ due to adsorption onto high surface area clay coatings.
Finally, methods for removing damage from immediate wellbore regions will be discussed and a new technique using specific pH buffered alcohols will be discussed with respect to system description and mechanism.
Laboratory Study of Lost Circulation Materials for Use in Oil-Base Drilling Muds
Authors: Nayberg T. M. , Petty B. R. 
Published: December 2007

Abstract
Lost circulation problems encountered in drilling are magnified when using expensive oil-base muds. There are many lost circulation materials (LCM's) that perform effectively in water-base drilling muds, but very few that work, well in oil-base muds. Those that do work well are effective in controlling seepage loss only.
A laboratory study was undertaken to compare the performance of conventional lost circulation materials with a new material composed of thermoset rubber in different oil-base drilling muds. Laboratory data are presented comparing the effectiveness of mica, modified hydrocarbons, cellulose fibers, ground walnut shells, a blend of fibers, flakes and granules, and thermoset rubber in controlling mud loss to simulated medium-size fractured formations. Included in the evaluation were tests performed in a low toxicity mineral oil-base mud, two invert emulsion oil-base muds, and two other oil-base muds (one heavily weighted).
It is shown that the LCM's specifically designed to combat lost circulation in oil-base drilling muds such as mica, modified hydrocarbons and cellulose fibers failed at all tested concentrations in all five oil-base muds. The other conventional materials such as walnut shells-coarse, a 2:1 blend of walnut shells-coarse and walnut shells-medium performed satisfactorily only at high concentrations in the five oil-base muds. The coarse blend of fibers, flakes and granules worked satisfactorily at high concentrations in one mud only. The thermoset rubber performed effectively at tested concentrations in all five oil-base muds.
Two interesting results were observed during this study. It was found that granular type LCM's, such as walnut shells-coarse and thermoset rubber-medium, sometimes exhibit a phenomenon called channeling effect. This channeling effect occurs when a high pressure differential and insufficient solids concentration in the mud (that cannot build and sustain a bridge at the formation face, or within the formation matrix) causes many channels to form within the LCM deposit, thus leading to mud or gas migration through the channels and, finally, to a test failure. It was also found in some drilling muds that high concentrations of walnut shells or thermoset rubber contribute to poorer performance than at lower LCM concentrations.
The effectiveness of the thermoset rubber LCM in oil-base drilling muds is believed to be due to: optimized particle size distribution, oil wettability, combination of particle strength and deformability, thermal stability and mud compatibility. Based on the results of this study, a solution to the problem of controlling the loss of oil-base muds to fractured formations is proposed. Comparative performance data are also presented to facilitate the use of the conventional LCM's as well as the thermoset rubber material in oil-base drilling muds.
A Simple Segregated Flow Model for a WAG Process
Authors: Hopkins C. W. , Wu C. H. , Poston S. W. 
Published: December 2007

ABSTRACT
A simple segregated flow model was developed to describe an alternate water and gas (WAG) injection process in a linear reservoir system. The model was developed based on the geometries of segregated fluid interfaces and on a volume balance of the injectants and the initial reservoir fluids. Results obtained from the model showed good agreement with published experimental and field data.
Assumptions in the model development includes immiscible water and gas phases, incompressible fluid flow, no trapped oil volumes and a uniform initial water saturation. Segregated flow interfaces depict the injected gas channeling to the top and the injected water channeling to the bottom of the oil zone. It assumes a pistonlike displacement and a fully segregated flow process.
The model tracks the progress of the respective interfaces and estimates the cumulative injection required to gas and water breakthrough. The model considers the fillup of initial free gas volume. The model can be easily extended to a five spot pattern by utilizing a streamtube approach, or by using an independently determined areal sweep efficiency.
A comparison of published experimental production data for different gas/water injection ratios with that predicted from the model showed excellent agreement. The model was satisfactorily used to predict the production performance of a field WAG process.
Extension of the Dykstra-Parsons Method to Layered-Composite Reservoirs
Authors: Tiab D. , Osman M. E. 
Published: December 2007

ABSTRACT
The Dykstra-Parsons method is often used to study the displacement of oil by water or gas in stratified reservoirs. These strata of different permeability are assumed to exhibit lateral continuity throughout the reservoir. In the proposed model, these strata are assumed to consist of several blocks with differenl transmissibility, kh/μ, and storage, ϕcth. According to Dykstra and Parsons, the displacing fluid sweeps faster through the more permeable zones so that much of the oil in the less permeable layers must be produced over a long period of time at high WOR. In this study, it is found that this is not necessarily true. It simply depends on the rock characteristics from layer-to-layer and from block-to-block. It is also found that waterflooding performance in layered-composite reservoirs is essentially controlled by the mobility ratio.
Equations giving the pressure drop, time of breakthrough, water-front location, coverage, WOR and cumulative oil recovery in a layered-composite reservoir are presented. Application of these equations to the case of constant injection pressure, which was not treated by the original Dykstra-Parsons method, is discussed.
A Method for Predicting Solution Gas-Drive Production Decline
Authors: Cummings C. A. , Gentry R. W. 
Published: December 2007

ABSTRACT
This study deals with projecting production decline curves. It examines a generalized relationship of cumulative production versus time presented in the literature by Gentry1. A production rate versus time relationship is derived from this general equation. Four methods of determining the constants appearing in both equations is presented. The equations are used to model solution-gas drive production (simulated and actual field case studies). The goal is to determine the uti1ity of using the equations to evaluate solution-gas drive reservoirs.
Densitometers for Mass Flow Determination of CO2
Authors: Ord R. 
Published: December 2007

ABSTRACT
Density is widely used in mass flow computations for custody transfer of supercritical CO2. Determination of density from densitometers is shown to be more reliable than estimation from temperature and pressure. Three types of vibrating element densitometers are described, and typical installation schemes are outlined. Advantages and disadvantages of each densitometer type are reviewed.
Corrosion Control in Enhanced Oil Recovery Wells
Authors: Martin R. L. , Braga T. G. 
Published: December 2007

ABSTRACT
Results of laboratory and field investigations are presented which illustrate corrosion identification and control in several types of EOR projects. Primary emphasis is given to producing wells in CO2 floods, in polymer or micell-polymer floods, and insitu combustion wells. Injection wells in these projects are considered briefly.
Based on corrosion measurements and measurements of sulfide, bicarbonate, and dissolved CO2 in produced fluids, effective corrosion inhibitors can be selected for corrosion control in all of the above conditions.
Interpretation of Temperature Profiles from the Steam-Stimulated Cold Lake Reservoir
Authors: Vittoratos E. 
Published: December 2007

ABSTRACT
Steam stimulation of the Cold Lake bitumen reservoir causes fracturing of the formation. Steam enters via convection along the fracture plane, and heat propagates perpendicular to this plane by conduction, which in some cases may be enhanced by convection. Temperature profiles from observation wells located around stimulated wells directly give the energy distribution at those locations. The analysis can be extended beyond energy distribution by distinguishing regions of convective and conductive heat transfer in the temperature profiles. Simple analytical models can then yield important insights into the cyclic steam stimulation process, such as fracture geometry and fluid flow velocity. Eight field cases are discussed representing profiles from the injection, shut-in, and production phases of the process.
A Comparison of Methods for the Representation of Three-Phase Relative Permeability Data
Authors: Parmeswar R. , Maerefat N. L. 
Published: December 2007

Abstract
With the advent of enhanced oil recovery (EOR) methods such as chemical flooding, miscible gas displacement and thermal methods, three-phase relative permeability data are needed to predict performances of field applications. Complexity of experimental and calculation procedures for three-phase relative permeability measurements is a primary reason why published data in this area are limited. Furthermore, arbitrary methods used for analysis and graphical representation of these experimental data are affected to some extent by subjective bias.
In this study, three-phase relative permeability data, reported previously by five other investigators are represented by a power law functional form with seven parameters to be estimated for each of the phases present. In this new approach, it is assumed that the relative permeability of a given phase is a function of the three fluid saturations. Results from the seven-parameter equations fit the experimental data throughout the three-phase range within experimental error (0.52%). To illustrate the accuracy of the isoperms predicted by the parametric method, these isoperms were compared with isoperms obtained by a graphical contouring technique. The graphical contouring technique uses a collection of local interpolation functions to calculate isoperms from experimental data and to plot on a triangular graph. This procedure eliminates errors resulting from subjective bias and is a true representation of the experimental data since it passes through all data points.
Comparison of the isoperms obtained by the parametric method with the isoperms plotted by the graphical contouring technique show that: (1) the parametric method gives a more reliable fit to the data points than manual techniques, because it is based on mathematical optimization and therefore eliminates subjective bias and (2) the graphical contouring method reveals the fluctuation in the original data points and possible smaller scale trends that may be significant. The functional form presented in this paper can be used to estimate three-phase relative permeability from displacement (unsteady state) core flood experimental results.
Effect of Ultrasonic Irradiation on Coalescense and Separation of Crude Oil-Water Emulsions
Authors: Schoeppel R.J. , Howard A.W. 
Published: December 2007

This paper was prepared for the 41st Annual Fall Meeting of the Society of Petroleum Engineers of AIME, to be held in Dallas, Tex., Oct. 2–5, 1966. Permission to copy is restricted to an abstract of not more than 300 words. Illustrations may not be copied. The abstract should contain conspicuous acknowledgment of where and by whom the paper is presented. Publication elsewhere after publication in the JOURNAL OF PETROLEUM TECHNOLOGY or the SOCIETY OF PETROLEUM ENGINEERS JOURNAL is usually granted upon request to the Editor of the appropriate journal provided agreement to give proper credit is made.
Discussion of this paper is invited. Three copies of any discussion should be sent to the Society of Petroleum Engineers office. Such discussion may be presented at the above meeting and, with the paper, may be considered for publication in one of the two SPE magazines.

Abstract
The coalescing and separating tendencies of untreated and treated crude oil-water emulsions when exposed to ultrasonic treatment are experimentally investigated. Combined ultrasonic and chemical treatment greatly increased separation efficiency over chemical treatment exposed only to low-frequency mechanical agitation. Both short- and long-duration ultrasonic irradiations were effective in producing coagulation: the rate of separation increased as much as 700-fold over natural settling rates.
The ultrasonic treatment technique offers a potentially practical method of improving natural oil-water coalescence and separation while simultaneously decreasing chemical requirements.

Introduction
One of the recurring problems which has bontinually plagued the oil industry is separation of water produced with oil. The significance of this problem is shown by an estimated 15 to 20 million dollars expended for chemicals each year to treat the world's oil production. This expense does not include costs for handling the demulsifier, injection equipment, heater fuel, etc.
Current methods of treating oil-water emulsions utilize natural settling, chemical dehydration, and/or electrical dehydration techniques to effect separation. Sonic energy may be used to cause either agglomeration or dispersion of immiscible liquids, depending upon frequency, wave energy, geometry, etc. A detailed literature survey revealed that, while a considerable amount of work has been done on sonic vibration as a coagulating force in aerosols and dust-gas systems, relatively little has been published on the use of this same force in separation of immiscible liquid systems. It is the purpose of this paper to present the results of an experimental investigation showing the capability of ultrasonic treatment to increase the rate of coalescence and settling of naturally occurring crude oil-water emulsions and increase the rate of dispersion of chemical demulsifying agents.
A Model for Prediction of Recovery and Pressure History for 2-D Displacement of Oil Through Porous Media by Gas/Surfactant
Authors: Mahmood S. M. , Tariq S. M. , Brigham W. E. 
Published: December 2007

ABSTRACT
The problem of predicting recovery and pressure behavior during gas/surfactant solution flooding is too complex to be treated analytically with the current state of knowledge. In the early stages of such displacements, the gas and surfactants are macroscopically dissociated and segregated, each flowing in separate channels. The in situ generation of foam does not seem to initiate until a certain mass of surfactant has been injected. Frontal advance theories such as the Buckley-Leverett theory or the Dietz model assume the injected fluid to be single phase, homogeneous, and non-reactive. Since these criteria are not met by the flow of gas and surfactant solution, these theories fail to accurately predict the recovery performance of such displacements.
Based on the observations made during a series of experiments on a scaled-model, a semi-analytical model is proposed to predict the oil recovery and pressure history from two-dimensional (x,z) systems undergoing gas/surfactant injection. The model is based on the concept of a combination flood, in which gas/foam and surfactant solution flow in separate gravity tongues. The gas/foam displacement is assumed to follow the Buckley Leverett theory, whereas the surfactant displacement follows the Dietz model. The displacements through these tongues are mutually dependent and, therefore, these theories are combined at each stage. The predictions from the model gave a good match with the experimental results for a fairly broad range of operating conditions. The semi-analytical approach adopted in developing the combination drive model has potential for application to certain other types of frontal behaviors.