bluuebunny/crossref_metadata_2025_split huggingface dataset:
Application of the Alkaline Flooding Process in the Torrance Field
Authors: Konopnicki D. T. , Zambrano L. G. 
Published: December 2007

ABSTRACT
An alkaline flooding system has been designed for application in the Main Zone reservoir of the Joughin Unit in the Torrance Field. The flood will encompass the major portion of the Unit (Section B) and will consist of twelve inverted nine-spot patterns. With a caustic injection rate of 38,000 BPD (6042 m3/d), this flood will be the largest alkaline flood ever attempted in the world to date. A 30% pore volume pre-flush injection, which consists of softened fresh water, began on June 30, 1981 to reduce the divalent ion content and salinity of the reservoir. A 16% pore volume caustic slug consisting of 1.2% sodium orthosilicate is scheduled to begin in early-1985. Caustic injection will require approximately two years.
Extensive laboratory studies have been conducted to verify the viability of the alkaline slug process in this reservoir. Interfacial tension measurements demonstrated that extremely low interfacial tensions can be achieved with a dilute solution of sodium orthosilicate in softened fresh water and reservoir brine. Furthermore, core floods utilizing sodium orthosilicate solutions of 0.8% and 1.2% resulted in reductions in the residual oil saturation of up to 9.4% Vp over waterflooding alone. This data along with the caustic consumption laboratory data were utilized in a chemical flooding simulator to scale results to the field and to make oil recovery predictions. The study indicates that the injection of a 16% Vp slug of 1.2% sodium orthosilicate will result in a incremental oil recovery of 1875 MBO (298,125 m3) or 1.75% OOIP in Section B. Results of the laboratory studies, reservoir engineering work, and the computer simulation study to optimize the process are presented.
A Group Contribution Activity Coefficient Model for Enhanced Oil Recovery Process Involving Electrolyte Solutions: Part I—Solutions in the Absence of Partial Molecular Association
Authors: Chien M. C. H. , Lee Sheng-Tai 
Published: December 2007

ABSTRACT
The assumption of ideal solution for the electrolyte solution in many mechanistic studies of enhanced oil recovery processes may be oversimplified because the mean ionic activity coefficient of an electrolyte is very sensitive to the mixture composition. A thermodynamic model is developed to account for the nonideality of electrolyte solutions and to serve as a tool for a more rigorous mechanistic study of enhanced oil recovery processes.
The model takes into account three important molecular and ionic force contributions: the long range ion-ion electrostatic force contribution, the intermediate range ion-solvent interaction (solvation) contribution and the short range force contribution of all species. It is demonstrated that the model can correlate the solution behavior of strongly polar and nonpolar nonelectrolytes as well as strong electrolytes over a wide range of concentrations. The solvation contribution is found to be important in correlating the thermodynamic properties, especially, the salting out of nonelectrolytes in aqueous solutions. Comparison shows that the new model is four times better than Chen's model (1982) in correlating the mean ionic activity coefficients. The parameters of sodium chloride, sodium hydroxide and calcium cation as well as magnesium cation are determined in this study. These parameters will be useful for the mechanistic study of alkaline flooding processes and surfactant/polymer flooding processes. Furthermore, the model employs the group contribution concept. Therefore, it can be used to estimate the solution behavior of a mixture in which the groups can be identified.
Analysis of Fracturing and Fluid-Flow Characteristics of the Monterey Formation, Santa Barbara Channel, CA
Authors: LaPointe P. R. , Belfield W. C. , Helwig J. A. 
Published: December 2007

ABSTRACT
Analysis of fracturing in the Monterey formation in core and outcrop demonstrates the interrelations among the regional stress field, the fracture pattern geometry and connectivity, and the hydrocarbon migration and production characteristics of the Monterey. The spatially and temporally persistent fracturing consists of four predominant subvertical sets striking approximately N30E, N55E, N67W and N15-30W. The northeasterly sets possess the greatest areal density and are often the primary set against which others terminate. They are also the most frequently filled with tar and calcite, particularly where they are near oblique-slip faults. A regional northeasterly maximum compressive stress field that has persisted from Pliocene time to the present selectively enhanced subvertical northeasterly-striking fractures. This stress field made the northeasterly joints the favored fractures for the migration of fluids through the fracture network.
Statistical analysis of the joint network indicates a northeasterly direction for the maximum fracture network permeability, consistent with offshore production data. Computer-generated synthetic fracture networks constructed from the field data illustrate the impact that faults, major joints and slump or breccia zones may have on integrating poorly connected fracture network clusters, thereby enhancing directional flows.
Analysis of Pressure Transient Data Obtained in Hydraulically Fractured Wells: A Field Example
Authors: Ross Steven E. 
Published: December 2007

ABSTRACT
The hydraulic fracture stimulation of low permeability reservoirs has been a successful technique for obtaining economic hydrocarbon production from many otherwise marginal fields.
The analysis of pressure transient data obtained in hydraulically fractured wells has been previously published by many authors.1–31
This paper utilizes these published theories for the purpose of illustrating that data from wells in a California Oil Field can be analyzed with the results used to guide future development.
The Performance Characteristics of a Hot Flowing Steamflood Production Well
Authors: Jurinak J. J. 
Published: December 2007

ABSTRACT
The production of hot steamflood fluids as a low pressure vapor/liquid mixture driven by produced steam or by the flashing of hot liquids is studied using a numerical wellbore flow model. The effect of well depth, wellhead pressure, flow rate, tubing size, and wellbore heat loss on the performance of the flowing steamflood well is discussed. The wellbore model is also used to estimate the flowing production well bottom-hole history in a FAST process tar sand steamflood. The rate of noncondensible gas injection required for auxiliary lift in a cold well is determined. This study facilitates application of produced steam lift as a steamflood production technique.
Caustic Consumption by a Sandstone at Elevated Temperatures
Authors: Dehghani Kaveh , Handy L. L. 
Published: December 2007

ABSTRACT
The effect of temperature on caustic loss due to its reaction with a representative sandstone was investigated in a series of laboratory experiments.
Consumption was measured for sodium hydroxide concentrations from 0.01 to 0.1 N at temperatures from 80° to 180°C in fired and unfired Berea sandstone. Three types of experiment were performed. One of these was a static, batch experiment with disaggregated sandstone for different contact times. The others were flow experiments in consolidated cores at various flow rates. In one case caustic was injected and effluent concentration were measured, and, in the other case, the produced fluids were recycled through the core.
The results show that caustic concentration is caused by a fast reversible Langmuir-type ion exchange and an irreversible reaction of dissolution of silica. An increase in temperature results in a higher amount of ion exchange for the same initial concentration and a higher rate of dissolution. The heat of the ion exchange reaction is constant in the range of temperature studied and as a result the equilibrium constant of ion exchange can be found for other temperatures. Dissolution for the lowest caustic initial concentration (0.01 N) can be represented by first order reaction but not for the higher injection concentration. Batch experimental results show that equilibrium is established in the caustic-silica reaction with stabilization of pH.
A New Drilling Technique Using Vortex Action at Rock-Bit Interface (Part 1)
Authors: Hayatdavoudi A. , Akhigbe A. , Okoye C. , Ghalambor A. 
Published: December 2007

ABSTRACT
Due to a great deal of information available, this paper has been arranged in two parts. The paper presented here deals with Part I. In this part, theory and laboratory data of the DVG (Downhole Vortex Generator) Sub, which is run immediately on top of the standard bits, is introduced. In our models, we have emphasized changes in drilling strengths and crossflow as a result of vortex action.
The theoretical as well as field data indicate an average increase of penetration rate to fall within 10 to 75 percent for 9-7/8″ holes. Furthermore, on the basis of laboratory data, it was concluded that (1) the vortex pressure drop increases as the DVG sub nozzle angle to the horizontal plane decreases, (2) there is a non-linear increase of the vortex pressure drop with flowrate, (3) the DVG sub maximizes the crossflow velocities below the jet bit by suppressing the impact vortex formed as a result of the jet impact near the cones.
Geological and Production Characteristics of the Nonmarine Part of the Mesaverde Group, Rulison Field Area, Piceance Basin, CO
Authors: Peterson R. E. 
Published: December 2007

ABSTRACT
Trends of subsurface structure, total sandstone isopachs and thickness variations are used to geologically characterize the depositional subdivisions of the non-marine part of the Mesaverde Group in the Rulison Field area of the southern Piceance Basin. Investigation of a gas production trend indicates that higher productivity may be controlled by structure induced fracturing and is independent of thicker sandstone accumulations. In addition, over-pressured gas reservoirs in a non-marine part of the Mesaverde Group have not been fully evaluated and may be an important exploration target.
Energy Transmission in Percussive Drilling
Authors: Fairhurst C. 
Published: December 2007

Abstract
A simple analysis of the mechanics of stress and energy transmission in percussive drilling is presented. Four basic components of the system are recognized:the hammer,the drill rod,the bit, andthe rock and the effect of each in determining the ultimate energy transmitted into the rock is considered.
Experiments to check the validity of simple theory are described, indicating reasonable agreement with the predicted square wave form generated by the hammer. Further work is required to fully check the theory of transmission through a conical bit. Experimental determination of the force-displacement characteristic of the rock for a given bit configuration is required before a more complete analysis is possible.

Introduction
Percussive drilling is a process of rock drilling in which repeated blows are applied to the rock surface through a pointed tool. Basically, it is probably the oldest known method. It is still, however, the most successful way of drilling hard rock and has recently been improved by the development of the percussive-rotary technique, in which positive rotation of the tool, together with a high static thrust on it, have been superimposed on the basic percussive action.
This paper describes work in progress at the U. of Minnesota to study the factors influencing stress and energy transmission in percussive drilling as a first step towards obtaining an understanding of percussive-rotary drilling.

Theory
It will be assumed that all of the energy used in rock breakdown in the percussive drilling system is transmitted from the hammer to the rock in the form of longitudinal vibrations of the drill rod. Due to the mathematical difficulty of satisfying boundary conditions, no exact solution to the problem of longitudinal vibrations in a finite elastic bar has been obtained. By making simplifying assumptions of varying degree several approximate solutions have been obtained.
Sand Fracturing vs. Fracture Acidizing
Authors: Bailey D. E. , Wickham J. F. 
Published: December 2007

ABSTRACT
Two producing oil wells were used against a fracture model to determine actual fracture parameters. Results of these comparisons was used to examine possible acid jobs of cost equivalent stimulation. The results of these comparisons are discussed. The fracture model was also used to look at different sized treatments to get seme idea on optimum size job that should be run. The economics of net present worth, benefit cost ratio, continuous internal rate of return and internal rate of return are examined.
An Accurate Method for Extending the Analysis of C7+
Authors: Ahmed T. H. , Cady G. V. , Story A. L. , Verma Vidya , Banerjee Salil 
Published: December 2007

ABSTRACT
The main objective of this paper is to present an accurate method for extending the molar distribution of the heptanes-plus fraction. The method originated from studying the extended analysis of ten natural gas-condensate mextures. A FORTRAN subroutine to perform this computation is presented, along with a graphical form of the proposed method.
Pressure Drawdown and Buildup Analysis Techniques for Reservoir Monitoring Tests
Authors: Murphy R. J. 
Published: December 2007

ABSTRACT
Methods for analysing drawdown and buildup data during reservoir monitoring test sequences are described and illustrated. Reservoir monitoring well tests are characterised by a short shut-in period to run pressure gauges followed by a drawdown-buildup sequence.
A new approach to analysing drawdown test data following a short shut-in period during reservoir monitoring efforts is presented. The method employs a variation of the classical Horner1 plot technique and is applicable to radial flow and pseudo radial flow systems. The flowing bottomhole pressure immediately prior to running the gauges in the hole can be determined from the plot and thus aid in the analysis of the first shut-in period data.
The effect of the ratio of the first shut-in period to the test drawdown period on the final shut-in Horner plot slope is presented. The correct method of plotting the final buildup data along with the error involved by using conventional plotting techniques is discussed.
Analytical Solutions for Pressure Buildup and Falloff Analysis of Water Injection Tests of Partially Penetrating Wells: Nonunit Mobility Ratios
Authors: Thambynayagam R. K. M. 
Published: December 2007

ABSTRACT
Approximate analytic solutions are presented for pressure build-up and fall-off analysis of water injection tests of partially penetrating wells. The three basic cases of interests, infinite, bounded and constant pressure outer boundary reservoirs are considered. The validity of the analytic solutions are demonstrated by comparison with the results of a conventional black oil finite difference program. The method allows reservoir characteristics to be determined from short-term water injection tests.
Evaluation of Clay Control Additives for Matrix Acidizing Operations
Authors: Hsi C. D. 
Published: December 2007

ABSTRACT
Clay control additives are often used in matrix acidizing operations to minimize formation permeability damages and to prolong stimulation results. However, some of these additives were developed originally for application in fracturing fluids, and their performance and stability in strong acidic solutions have not been thoroughly tested.
In the study, the clay stabilization performances of one inorganic and three organic polymer type clay control additives were evaluated using core flow tests. The relative effectiveness of an individual additive was judged by its ability to prevent permeability damages due to either chemical incompatibility (fresh-water sensitivity) or mechanical dislodging (particle migration) at higher fluid velocities. The influence of temperature, acid concentration and carrier fluid composition on their performance was also studied.
Results indicate that some additives are not effective in preventing fresh-water sensitivity when applied di rectly in acids. Test results were also compared with cores treated with HCl-HF acid under similar conditions. In general, HCl-HF acid treatments are more effective than clay control additive type treatments in preventing permeability damages due to mechanical dislodging (particle migration) at high fluid velocities. The advantages and disadvantages of each method in preventing formation damages during matrix stimulation are also discussed.
Three Strategic Improvements in Petroleum Investment Analysis
Authors: Cotton F. E. 
Published: December 2007

ABSTRACT
High rates of inflation, interest, and discounting have increased the degree and importance of error in evaluating investments and in making investment decisions. This is particularly strategic to investment-intensive industries such as petroleum and to high-growth industries such as high technology.
The petroleum industry can offest this error by modifying its use of payout, by using inflation-adjusted profitability measures, and by incorporating new options and several refinements that are especially vital to long-term investments.
Case History: Underbalance Drilling the Midway and Navarro Formations Successfully in Hallettsville, TX
Authors: Louison R. F. , Reese R. T. , Andrews J. P. 
Published: December 2007

ABSTRACT
Underbalanced drilling proves to be a sound and economical procedure with an average of $500 M being saved per well. An average reduction of 19 days to total depth has also been experienced with this method of drilling.
The major advantages of drilling underbalanced are lower cost, reduced drilling days, and reduced trouble time (i.e., differential sticking and hole drag due to thick mud cake across shallow depleted Wilcox sands).
Analysis of Alcoholic and Thiocyanate Type Tracers in Core Studies and Field Samples
Authors: Gregory S. D. , Kocsis D. L. 
Published: December 2007

ABSTRACT
Analytical techniques have been developed and validated for the determination of alcoholic and thiocyanate tracer content. The tracer content was determined in steamflood production effluent and in low interfacial tension (LIFT) injection and production fluids.
A gas chromatographic procedure was used for determining alcohol content and a complexation/colorimetric detection technique was employed for the analysis of thiocyanate tracers. The procedures have been automated to allow for maximum sample throughput and minimum operator interaction. As many as 66 samples can be analyzed automatically per day. The tracer analyses have been employed in the analysis of laboratory core samples and field production samples.
The Effect of Decontrol on the Price of Natural Gas
Authors: Horvath R. S. 
Published: December 2007

ABSTRACT
Under the NGPA, the wellhead prices of certain categories of interstate natural gas are partially decontrolled on January 1, 1985. It is generally acknowledged that unless producer/pipeline contracts are renegotiated, the average price of interstate natural gas may increase upon decontrol. The determination of the average price increase in 1985 depends on the mix of contracts and their provisions, as well as on the mix of gas as categorized by the NGPA. This paper summarizes the analysis of a survey of interstate natural gas pipelines to estimate the 1985 average price increase, focusing on the variations within the pipeline industry.
Trends in Natural Gas Regulation
Authors: Kumar J. , Griggs J. W. 
Published: December 2007

ABSTRACT
In recent years the natural gas market in the United States has been beset with high prices for consumers, declining demand for natural gas and excess quantities of deliverable natural gas. These market distortions are a result of existing regulation and pipeline marketing practices. Legislation to address these problems has been introduced in the U.S. Congress. This paper assesses the current problems and the prospects for change in the regulatory environment.
A Simplified Procedure for Gas Deliverability Calculations Using Dimensionless IPR Curves
Authors: Mishra S. , Caudle B. H. 
Published: December 2007

ABSTRACT
A new method for deliverability calculations of gas wells, which eliminates the need for conventional multipoint tests, is presented. Using the analytical solution for real gas flow under stabilized conditions, and a broad range of rock and fluid properties, an empirical relation for calculating gas well deliverability in an unfractured reservoir is developed. This relationship is similar to Vogel's dimensionless Inflow Performance Relation (IPR) for solution-gas drive reservoirs. Also developed in this study is a second empirical relation, which estimates future deliverability from current flow test data. A simple procedure for gas deliverability calculations, utilising these two relations, is suggested.
A Statistical Structural Model for Unsteady-State Displacement in Porous Media
Authors: Alemán-Gomez M. , Ramamohan T. R. , Slattery J. C. 
Published: December 2007

ABSTRACT
A statistical structural model was used in the context of local volume averaging to examine the effects of interfacial tension, the interfacial viscosities, and wetting upon the capillary pressure and relative permeability functions in an unsteady-state displacement. The statistical structural model is a highly simplified idealization of the local pore structure, in which pores are randomly oriented in space, but no pore interconnections are recognized.
Whether we are concerned with an imbibition or a drainage, it is not important to distinguish between steady-state and unsteady-state relative permeabilities when the local capillary number Nca &lt;&lt; 1. Unless the interfacial tension is very small everywhere or the overall pressure gradient very large, it may be satisfactory to use steady-state representations for the relative permeabilities everywhere except in the immediate neighborhood of a displacement front. The local capillary number Nca will always be largest in the immediate neighborhood of the displacement front. Within the immediate neighborhood of a displacement front, simulations, especially of imbibitions, should employ unsteady-state relative permeabilities.
Evaluation of the Influence of In-Situ Reservoir Conditions on the Geometry of Hydraulic Fractures Using a 3D Simulator
Authors: Dougherty R. L. , Abou-Sayed A. S. 
Published: December 2007

ABSTRACT
The effectiveness of hydraulic fracturing in most applications is directly dependent upon the geometry of fractures created within the layered reservoir[l,2]. Therefore, design of fracturing treatments is generally based on maximizing fracture length and propped width (conductivity) while maintaining fracture height as close to pay zone height as possible [c.f. 3, 4]. In certain situations, such as the proximity of the pay zone to a water aquifer, vertical fracture extension could become critical. Hence, fracture geometry calculations that do not assume a constant fracture height have become necessary requirements for optimum treatment design.
This paper discusses a three-dimensional model, "HYFRAC", and shows its applicability to fracture geometry prediction for a wide variety of conditions. The results of the 3-D fracture analysis can be employed to validate and/or evaluate currently used models and theories of fracture growth. Comparisons will be made with Perkins and Kern predictions of constant height growth [5], with Geertsma-DeKlerk[6] and with methods using downhole pressure variation to determine fracture growth and stability[7]. Results from other current models will also be compared to HYFRAC results. Such studies will help determine the strengths and weaknesses of the available models. This will provide a better understanding of when problems require a fully three-dimensional solution and when a two-dimensional, quasithree-dimensional, or other analysis may suffice.