bluuebunny/crossref_metadata_2025_split huggingface dataset:
Beyond Alkaline Flooding: Design of Complete Chemical Systems
Authors: Krumrine P. H. , Falcone J. S. 
Published: December 2007

Abstract
The design of chemical flooding systems has been and remains quite complex due to the many interactions that can occur between not only the various constituents in the chemical slug but also with the reservoir itself. This paper discusses many of the interactions that occur between surfactants, polymers and alkalis in a mixed system design. Specific focus is directed towards the benefits mixed alkalis impart to the overall design such as 1) water and reservoir conditioning, 2) adsorption/retention reduction, 3) emulsification improvement, 4) wettability alteration, and 5) improved sweep efficiency and mobility control.
Data are presented and discussed to show how such systems can be designed and what parameters to consider in maximizing chemical survivability, transport, and effectiveness. Effects such as consumption, ion exchange, precipitation, and propagation are discussed for a buffered mixed alkali that is tailored to a specific reservoir environment. This approach expands the horizon for alkaline chemicals and indicates one of the few remaining economically feasible directions for chemical recovery systems in todays oil market.
OPEC and Adam Smith: Part II
Authors: Roberts M. L. 
Published: December 2007

Abstract
OPEC's failure to discipline itself clearly suggests that that organization refuses to acknowledge that Adam Smith is alive and well. Thus, the pain of Economics 101 is making itself felt through lower crude prices and a competitive fight for market share. The current fight by OPEC for increased market share is a direct result of its two quantum jumps in energy prices during the decade of the 1970s. The ten to twenty fold increase in oil prices set in motion irreversible forces that have changed the structural demand for energy which reduced by about 50% the historic growth relationship of energy to economic activity. In addition, the quantum jump in energy prices has encouraged the incremental supply of non-OPEC oil and non-petroleum energy at an annual rate of 1.0–2.0 million BD per year.
Since the beginning of 1986, OPEC in general, and Saudi Arabia and the Gulf States in particular, have made a decision to flood the market with oil and thereby reduce prices (rather than prorate production and increase prices) in an attempt to regain their historic market share of 54%, up from the current 31%. The degree to which they are successful at this game will depend almost entirely on the following factors: (1) the rapidity with which existing non-OPEC oil production declines; (2) the degree to which non-OPEC oil reserves are replaced; and (3) the degree to which the structural changes in demand will be re-altered at current prices of some 50% less than those experienced in late 1985.
This paper will discuss these issues by focusing on the forces of supply, demand and pricing and how they are changing the characteristics of the industry.
Importance of Cost/Price Relationships for Least-Cost Oil and Gas Reserves
Authors: Kuuskraa V. A. , Morra F. , Godec M. L. 
Published: December 2007

Abstract
Traditional economic analysis suffers when oil and natural gas prices are on a roller coaster. On the ride up, there are expectations of massive profits. On the ride down, there are dire predictions of economic doom, of outflight of capital, and of collapse in drilling. However, a narrow focus on only oil prices misses the point that costs also rise and fall with prices.
This paper examines the interdependent roles of prices, costs, and efficiency on the economics of domestic oil and gas supplies by addressing three points:
Historical relationship of costs and prices since the early 1970's; Change in relative oil and gas supply economics since the "energy crises" through today; Implications of the cost/price relationship on "least-cost" strategies for oil and gas reserves and alternate fuels.
The paper concludes with several examples to show where proper use of cost/price relationships could improve industrial and public policy decision making in energy.
An Analysis of Supply and Demand for Crude Oil
Authors: Cecil R. E. 
Published: December 2007

Abstract
Valuation of oil and gas producing properties requires projections of production rates, product prices, taxes to be paid and operating expenses. Production forecasts are based on engineering analysis with considerations given to equipment capacity, well deliverability and demand. Current laws normally govern tax considerations, although legislation under consideration must also be recognized. Past expenses coupled with estimates relative to inflation provide the basis for estimates of future expenses. Price forecasts have been dependent upon current prices with estimates as to future inflation rates. Therefore, the appraiser of an oil and gas property must have not only a geotechnical background but also an understanding of economics and finance.
Until the early 1970's, the oil industry had primarily focused economic analysis on domestic supply and demand. As this demand exceeded the supply, resulting in increased levels of imports, attention turned to supplies outside the United States. Today our evaluations require analysis of worldwide economic factors when projecting production rates, prices and expenses. Estimates of crude oil supply relative to the price for the various producing nations have been made, thereby providing supply schedules with the attendant supply curves. Estimates of world demand were made to obtain demand schedules and demand curves. The supply and demand curves have been brought together to provide the estimated equilibrium price for oil.
Financing Projects via Turnkey Contractors
Authors: Marple G. T. , Ruley G. E. 
Published: December 2007

Abstract
Exploration for oil and gas is a capital intensive endeavor, and the sudden and severe change in environmental conditions has drastically reduced this necessary resource. The critical missing element in the oil and gas industry right now is not the lack of economically viable projects, rather, it is the lack of capital. However, by breaking with the traditional relationship between a service company and an oil company, projects can be "financed" today without the need for an intermediary such as a bank. Cox Oil & Gas, Inc., among others, has been successful at structuring a program which has achieved getting wells drilled for their account without having to allocate any of their own capital resources.
True Government Take (TGT): A Measurement of Fiscal Terms
Authors: Smith D. E. 
Published: December 2007

ABSTRACT
Companies involved in international exploration/production are always faced with the question of which countries have the most favorable fiscal terms. The typical way of analyzing this problem is to compare tax rates or profit splits. This task becomes much more difficult though, when an attempt is made to compare the terms of countries which vary considerably in their fiscal methodology. The True Government Take (TGT) is a quantitative indicator that measures the overall effect of a particular fiscal system and thus allows more meaningful comparisons between countries.
The Impact of the New Tax Law on Internal Cash Flow Generation
Authors: Thompson R. S. 
Published: December 2007

ABSTRACT
The impact of The Tax Reform Act of 1986 on the ability of the integrated oil producer and the independent oil producer to generate cash from internal sources is investigated. How did the oil industry fair in the most recent tax reform battle. Obviously, the impact of the new tax law will vary from company to company depending on the specific tax situation of the company. The changes affecting the oil industry appear at first glance to be relatively minor. However, changes in the alternative minimum tax calculations are significant and could add to the tax burden in some years. Each year tax reform manages to chip away at some of the preferential treatment that the oil industry receives for certain capital expenditures. The 1986 Tax Reform Act is not an exception. However, the oil industy probably would have been "hit" harder had it not been for the current weak economic condition of the industry.
Oil Futures and Options Increase in Importance in Volatile Industry Conditions
Authors: Hill J. 
Published: December 2007

ABSTRACT
The oil market of the late 1980's and into the 1990's is likely to be characterized by price uncertainty and volatility. The oil futures and options markets have developed to meet the needs of the petroleum industry to find a supplementary vehicle to reduce some of the risk surrounding pricing. This paper provides an introduction to the use of crude oil futures and options hedging by oil and gas producers.
The Impact of the New Tax Law on Project Evaluation
Authors: Wright J. D. , Thompson R. S. , Shipley S. E. 
Published: December 2007

ABSTRACT
The Tax Reform Act of 1986 contains few provisions aimed specifically at the oil and gas industry. It does, however, contain dramatic changes for both individuals and corporations as a whole. The effect of some of the major changes is discussed from the viewpoint of project evaluation. Three representative projects- a drilling deal, a field development and waterflood, and an acquisition were studied.
If the Alternative Minimum Tax is not included, it appears that the new tax law does not significantly change the present value of typical oil and gas projects. Compared to the old tax law, the new law increases the tax liability in the early years of a project and decreases it in later years.
Cyclic Steam Stimulation in a Tight Clay-Rich Reservoir
Authors: Watkins D. R. , Kalfayan L. J. , Blaser S. M. 
Published: December 2007

ABSTRACT
During the past several years, two proprietary-fines stabilizing processes have been field tested in conjunction with cyclic steam stimulation at So. Tapo Canyon Field, Ventura County, California. The Fourth Sespe Formation, the producing zone, is a low-permeability sand (&lt;35 md) containing an abundance of clay and non-clay fines. It is characterized by rapid production decline and extreme water sensitivity. Laboratory tests demonstrate the potential for damage by formation fines as well as the effectiveness of the experimental processes in preventing damage.
The field tests resulted in widely varying steam responses. This paper describes the differences in steam responses and provides an explanation for some of these differences. Factors that appear to affect steam response include reservoir pressure, changes in oil composition caused by steam injection and heat transfer efficiency. Two wells demonstrated long term stimulation beyond the thermal effects.
Overall, the field tests demonstrated that the Sespe can be steam stimulated without damage.
Numerical Model for Evaluating Concentric Steam Injection Wells
Authors: Griston S. , Willhite G. P. 
Published: December 2007

ABSTRACT
A mathematical model was developed to evaluate wellbore heat losses and two-phase pressure drop in concentric-pipe steam injection wells. The model is based upon the equations for conservation of mass, momentum, and energy within each pipe, heat loss in the wellbore, and heat conduction to the formation.
In the model, pressure drop in each pipe is determined from momentum balance equations and include liquid hold-up and flow regime correlations for two-phase flow. Heat transfer between the concentric pipes is calculated based on the combined thermal resistance of vaporization/condensation on each surface of the inner pipe and conduction through the inner pipe wall. Additionally, heat is lost from the outer pipe to the formation at the cement-formation interface. Transient heat-conduction in the formation is also taken into account. The computation procedure consists of it-eratively solving two sets of momentum and energy balance equations in a stepwise manner over a specified length of the well.
The model has been verified for single-pipe injection wells with a dry casing annulus, by comparing predicted and actual field data. Predicted temperatures and pressures showed very good agreement with measured temperature and pressure profile data. Model calculations for concentric injection have not been validated against field data; however, the predicted boiloff problems have been qualitatively verified in the field by the severe scale buildup found in either the inner or outer pipe of many Chevron concentric wells used in the Kern River and Coalinga areas.
Numerous test cases were run to study the effects of injection rate, injection pressure, injection quality, pipe sizes, and insulation on concentric steam injection. The results of this study indicate that heat transfer between the concentric pipes is very high, resulting in an unintended distribution of heat, steam quality, and pressure exiting each pipe and often causes steam boiloff (100% vaporization) in one of the pipes. Insulated tubing can effectively reduce the heat transfer, but certain practical limitations require close evaluation of its use.
Three-Phase PVT and CO2 Partitioning
Authors: Vetter O. J. , Bent M. , Kandarpa V. , Salzman D. , Williams R. 
Published: December 2007

Abstract
Flashing of reservoir liquids and their associated PVT behavior is critical for many oil field operations. Conventional PVT work considers only the reservoir oil and its gas flash behavior. The presence of a water phase in the reservoir is normally neglected. It is assumed that water does not flash below its boiling point. This assumption is justified to some degree if the system contains no components which are soluble both in the water and oil such as CO2 and other gases. Most reservoir fluids contain such gases. Therefore, the conventional bubble point considerations as used for field operations are conceptually wrong. Using only two-phase PVT data in petroleum operations when in reality a three-phase system exists in the field as commonly done could conceivably generate various problems related not only to the proper reservoir management but also to handling of carbonate or sulfide scale problems.
The experimental data on (a) three-phase PVT work and (b) CO2 partitioning effects between oil and water under various conditions are discussed. Actual and different oil/water/gas systems from three California reservoirs were examined.
The results of this work show that the three-phase PVT data are extremely important under the following field conditions: The WOR is varying and high.The GOR is varying and high.The concentration of CO2 and/or other gases which can dissolve in both oil and water phases is high.The water breakthrough occurs in a waterflooded reservoir.During CO2 flood operations.A carbonate or sulfide scale problem exists anywhere in the field.Application of inhibitors to prevent the formation of various types of scale.
In principle, the phase behavior of reservoir and/or produced fluids as well as.the associated CO2 partitioning effects between the various phases depend upon the following variables: Pressure and pressure changes.Temperature and temperature changes.CO2 concentration in any of the three fluid phases potentially existing in the reservoir prior and anywhere in the system, during and after flashing of the reservoir fluids.Composition of reservoir brine (including pH), oil and gas.WOP, GOR and GWE under any set of pressure and temperature conditions.
The present paper discusses the importance of three-phase PVT data (including bubble point and flash behavior in the presence of CO2) and CO2 partitioning data for oilfield operations. Sampling, testing and computational procedures are described. All the discussions are supported through three-phase PVT data generated in the laboratory for three different types of reservoir fluids from California fields.
Case History of Hydraulic Fracture Performance in the Naturally Fractured Paludal Zone: The Transitory Effects of Damage
Authors: Branagan P. T. , Cipolla C. L. , Lee S. J. , Yan L. 
Published: December 2007

ABSTRACT
The pre- and post-stimulation reservoir performance of two naturally fractured Paludal sandstones in the Mesaverde Group were thoroughly tested and evaluated. The transitory nature and effects of natural fracture damage caused by two stimulation experiments are illustrated. These two sandstone reservoirs, located at the Department of Energy (DOE) Multiwell Experiment (MWX) site, designated Paludal sands 3 and 4, were initially characterized by integrating a comprehensive set of core, log, seismic, geological, well testing and production data. The data set indicated that the dominant production mechanism in Paludal sands 3 and 4 was a set of anisotropic natural fractures. The identification, quantification and incorporation of this anisotropic natural fracture system is critical to the subsequent post-fracture production and well test analysis.
These reservoirs were modeled using a finite difference naturally fractured reservoir simulator. This simulator is capable of modeling transient matrix flow and provides the proper coupling of the propped hydraulic fracture with the anisotropic natural fracture system. The initial postfracture well tests and production data indicated that although these fracture treatments had been carefully designed and monitored, they did not properly achieve the desired enhancement. Subsequent reservoir modeling illustrated that these treatments had probably decreased the flow capacity of the natural fracture system near the hydraulic fracture, thus limiting the production capacity of the well.
The natural fracture damage was assumed to be the result of residual treatment liquids and/or fracturing fluid blockage. The magnitude of these damage mechanisms should decrease with time. Paludal sands 3 and 4 were subsequently isolated for 18 months and then re-tested. The reentry testing and production indicated that the initial post-fracture damage was no longer present. This paper details the genesis of reservoir behavior from the initial pre-fracture well tests through the period of poor post-fracture production to the current period of enhanced reservoir performance.
Pressure Transient Response in Multilayer Gas Reservoirs Containing Hydraulic Fractures
Authors: Sullivan R. B. , Lee W. J. , Holditch S. A. 
Published: December 2007

ABSTRACT
This paper presents a method to estimate induced fracture properties and reservoir geometry in multilayered gas reservoirs similar to the Travis Peak formation in East Texas. The Travis Peak is characterized by commingled production from small, high-permeability channel sands and blanket low permeability formations. Our specific objectives are to estimate fracture half-length, fracture conductivity, and area of the small, high-permeability layer in a two-layer reservoir system similar to the Travis Peak.
In this study, we developed constant rate drawdown type curves applicable for analyzing pressure buildup tests which follow production at constant bottomhole pressure. The results obtained from our type curves are used only as a starting point for a more rigorous numerical simulation (history-matching) study.
Our type curves assume the small, high permeability sand is a "channel" deposit, which is modeled with a 2×1 rectangle, whereas we assume the larger, lower permeability layer is a blanket-like deposit which can be modeled as a 160-acre square. A single vertical fracture of finite conductivity intercepts the wellbore and completely penetrates each layer, extending down the short side of the 2×1 rectangle.
Even though this paper presents a specific solution for a specific type of layered reservoir, it illustrates a general approach for analyzing other layered reservoirs with induced fractures and known geometry in the layers.
Quantitative Model of Overpressured Gas Resources of the Pinedale Anticline, Wyoming
Authors: Charpentier R. R. , Law B. E. , Prensky S. E. 
Published: December 2007

ABSTRACT
The Pinedale anticline, located in the northern part of the Green River basin of Wyoming, contains a large accumulation of overpressured natural gas within a low-permeability sequence of Upper Cretaceous rocks. The geologic factors which control the gas accumulation can be used to create a quantitative model of the accumulation. Such a model was constructed for the Pinedale anticline and used for a resource estimation. Within this 197 mi2 [317 km2] structure, the 10,000 ft [3048 m] section of overpressured rock is estimated to contain 159 tcf [4.50x1012 m3] of in-place natural gas in the sandstone reservoirs, although only a small part of this resource may be recoverable.
Application of Horizontal Drainhole Drilling Technology for Coalbed Methane Recovery
Authors: Logan T. L. , Schwoebel J. J. , Horner D. M. 
Published: December 2007

ABSTRACT
Methane gas contained in coal represents a potential new gas supply. Transformation of this large gas-in-place resource to reserves will depend on developments of modified and/or new completion methods to achieve long-term economic production. Coal reservoirs typically have very low matrix permeability with gas being desorbed from the matrix to the wellbore through a system of natural fractures or cleats. Due to low permeability, coal reservoirs usually require hydraulic fracture stimulation to achieve economic production. Investigations have shown that hydraulic fractures usually propagate parallel to the maximum stress or face cleat direction, and therefore may not adequately access an anisotropic reservoir. A more effective stimulation technique may be a horizontal borehole placed perpendicular to the maximum permeability direction. This paper discusses the application of drilling horizontal boreholes for coalbed methane recovery in two different situations: i) in a coal seam associated with an active underground coal mine, and ii) in a deeply buried unmineable coal seam.
Modified Fracture Pressure Decline Analysis Including Pressure-Dependent Leakoff
Authors: Castillo J. L. 
Published: December 2007

ABSTRACT
Nolte developed an analysis of the pressure decline following a fracturing treatment to provide an estimate of fluid efficiency, fluid loss coefficient, and fracture geometry. This analysis has become an industry standard for evaluating and improving the design of fracturing treatments. The derivations by Nolte assume the leakoff coefficient is a pressure-independent constant. This assumption is valid when leakoff is controlled by a compressible filter cake.
In cases where leakoff is primarily controlled by filtrate viscosity, by an incompressible filter cake, or by reservoir permeability and compressibility, the leakoff coefficient is pressure dependent, and, therefore, declines during the closure period. Under these circumstances, direct application of the Nolte technique may not be appropriate, and could cause an optimistic estimate of fluid efficiency and leakoff coefficient.
This paper introduces a new plot for fracture pressure decline analysis that determines the pressure parameters (ISIP, Pc, P*) required in the Nolte leakoff calculations. The derivative of this plot may be used to identify the extension period, the closure period, and to assess the influence of pressure dependent leakoff on fracture pressure decline. In order to account for pressure dependent leakoff, equations are presented where the leakoff coefficient is treated as a mathematical variable. The equations describe simple linear relations applicable to the fracture closure period. When these relations are plotted on Cartesian coordinates, the closure period is recognized by a straight line with slope proportional to the leakoff coefficient. As shown in the examples, this modified approach is easily applied and provides new insight to the fracture closure period.