bluuebunny/crossref_metadata_2025_split huggingface dataset:
A Method To Identify the Effects of No-Flow Boundaries Upon Pressure Buildup Data
Authors: Payne R. E. 
Published: December 2007

ABSTRACT
A technique has been developed to identify the effects of no-flow boundaries by using the deviation of pressure buildup data from the infinite-acting case. A dimensionless, pressure depletion group consisting of the measured initial reservoir pressure, the extrapolated pressure from the Horner plot and slope of the infinite acting data on the Horner plot is used as a parameter. The ratio of the late time slope to the middle time slope on a Horner plot is plotted against the Horner plot time. For a given value of the dimensionless pressure depletion group, these data are matched against the curves for a given boundary configuration. Analysis of actual field data has been included to illustrate this technique.
GEODYN2: A Bottomhole Assembly/Geological Formation Dynamic Interaction Computer Program
Authors: Baird J. A. , Caskey B. C. , Wormley D. N. , Stone C. M. 
Published: December 2007

ABSTRACT
This paper describes the current development of a three-dimensional transient dynamic finite element computer program, GEODYN2, capable of simulating the behavior of a rotating bottom hole assembly (BHA) interacting with a non-uniform formation. The GEODYN2 Program facilitates a very detailed analysis/ simulation of the behavior of a BHA with a polycrystalline diamond compact (PDC) bit and various stabilizer designs. The basic drill string mechanics implemented within the program, the overall algorithm, and the more pertinent modeling features which permit this level of analysis are briefly outlined. The implementation of these features and how they allow calculation of the response behavior of a bottom hole assembly are demonstrated. Although the development and enhancement of modeling capabilities within GEODYN2 is ongoing, it is anticipated that the preliminary verification results thus far generated will further the understanding of the response behavior of BHAs.
Probabilistic Stability Analysis of Multiphase Flow in Porous Media
Authors: King M. J. , Scher H. 
Published: December 2007

ABSTRACT
The problem of viscous fingering in multi-phase fluid flow in porous media affects the understanding, design, and evaluation of both laboratory experiments and reservoir processes. Existing methods of studying fingered floods are either phenomenological, or rely heavily on high order numerical methods. In this work, a novel "random walk" analysis is described and utilized to study both miscible and immiscible floods. Simple "walking" and "trapping" rules are derived directly from the usual differential equations describing multi-phase flow. It is straight forward to include the effects of capillary pressure, heterogeneity, diffusion-dispersion, gravity, different geometries, and to study multiple (&gt;2) phase flow.
The random walk model implicitly performs a stability analysis as the flood proceeds. The solutions vary from compact to highly fingered profiles, depending upon the value of the mobility ratio, M. The entire range of displacements, from stable to unstable, may be simulated.
The random walk methods are an extension of the diffusion-limited aggregation (DLA) model of Witten and Sander. The concept of trapping has been substantially generalized beyond that of DLA. The DLA rules are recovered dynamically as a special case in the extreme mobility (M → ∞) limit.
Replacement Costs of Domestic Natural Gas
Authors: Kuuskraa V. A. , Morra F. 
Published: December 2007

ABSTRACT
As the country uses its reserves of natural gas, it will need to continually replenish them if production is to be maintained. The outlays associated with this continuing search, development and production of new reserves is defined as "replacement costs." Thus, the replacement cost of natural gas is the minimum selling price a firm must receive to recover its costs and to achieve a reasonable return on capital.
This paper estimates the range of natural gas replacement costs to the year 2010 and measures the uncertainty associated with these estimates due to the size of the underlying resource base, new unconventional gas extraction technologies, and the rate of domestic gas production.
Drilling with PDC Bits on Rotary vs. Downhole Motor: Southeast Central Texas Austin Chalk Fields
Authors: Pain D. D. , Johnson E. T. , Byers R. H. , Vader E. R. 
Published: December 2007

ABSTRACT
Polycrystalline diamond compact (PDC) drill bits have proven to be economical in the Austin Chalk fields in Southeast Central Texas. Many contractors have expressed concerns over reduced drill pipe life when using the PDC bits on rotary because of the higher rotating speeds and higher bit torque. Field results and economic analyses show that PDC bits are more cost-effective, even with reduced drill pipe life, than roller-cone bits in the proper formations. These results also show that the use of downhole motors in conjunction with PDC bits can eliminate the problem of premature drill pipe failures, while still resulting in lower overall drilling costs and fewer days to drill a well.
Surfactants for CO2 Foam Flooding
Authors: Borchardt J. K. , Bright D. B. , Dickson M. K. , Wellington S. L. 
Published: December 2007

ABSTRACT
A great deal of information has been published on the use of surfactants in CO2 foam flooding applications. However, generally the chemical composition of the surfactant has not been specified and little work describing the relationship of surfactant chemical structure and physical properties to foaming agent performance has been reported. This laboratory study examines the performance of more than 40 surfactants in 1 atmosphere foaming experiments. Several classes of surfactants were studied including alcohol ethoxylates, alcohol ethoxysulfates, alcohol ethoxyethylsulfonates and alcohol ethoxyglycerylsulfonates.
Surfactants which performed well in the 1 atmosphere (1.01 X 105 Pa) foaming experiment were also good foaming agents in sight cell and core flood experiments1,2 performed in the presence of CO2 and reservoir fluids under realistic reservoir temperature and pressure conditions.
Field Test of CO2 Mobility Control at Rock Creek
Authors: Heller J. P. , Boone D. A. , Watts R. J. 
Published: December 2007

ABSTRACT
This paper reports the objectives, design and progress of a field test of "CO2-foam" as a lowered mobility displacing fluid. It includes the background of mobility control considerations leading to the trial, and describes the influence on it of various operational conditions and constraints. The Rock Creek oil field of Roane County, West Virginia, has been produced since 1906 from a low permeability sandstone with high clay content, and is now near the end of economic life. The area utilized in this test is a smaller portion of two ten-acre five-spots that have been subjected to a conventional CO2 flood and subsequent waterflooding, in addition to gas recycling and primary production. A major goal of the test was to determine whether the oil remaining in this area could be displaced by a slug of thickened CO2 to form a mobile oil bank that could be detected at a nearby observation well. A second goal was to test the injectivity of CO2-foam as liquid CO2 and dilute surfactant solution were pumped simultaneously down fiberglass tubing into the injection well. The design of the test was based on published measurements of the ability of the chosen surfactant (Alipal CD128) to form a foam-like dispersion with liquid CO2, on stability at reservoir temperature (73°F; 23°C), on the extent of adsorption onto the reservoir rock, and on the appropriate values of the relative mobility of the CO2-foam (0.2 cp−1). Although it has been possible to inject more than half of the specified quantity of CO2-foam, lowered injectivity and other field circumstances have as yet prevented the test from proceeding far enough to show an unequivocal result for the first objective.
Prediction of Compositional Grading in a Reservoir Fluid Column
Authors: Montel F. , Gouel P. L. 
Published: December 2007

ABSTRACT
A method of predicting fluid compositional grading with depth is presented. It was designed to enable numerical simulations of this phenomena, now required in compositional model studies: the nature of petroleum fluids today (condensate gases, volatile oils, "critical" fluids) increases this need.
Based on ONSAGER's theory, general relations between compositional grading of a fluid with depth make predictive calculations of this evolution possible.
Our method only takes into account the gravitational effect; it enables to calculate the phase behavior of a fluid everywhere in a column, assuming the stationary state has been reached. The proposed algorithm is an iterative calculation based on the fugacities of each component at different depths; knowing pressure, temperature and overall composition at a reference depth we can predict the compositional grading, gas-oil contact location and even physical state change with depth.
The required conditions to realize such a prediction are discussed.
In addition, a "new" thermodynamic fitting method is suggested.
An example is given for a North Sea real "critical" fluid; it clearly shows that the gravitational segregation alone can largely explain the compositional grading observed in the reservoir.
PVT and compositional simulations of the fluid are based on the PENG-ROBINSON's equation of state1 but this method can be developed with any other equation.
Wm. Berryhill Micellar Polymer Project: A Case History
Authors: Crawford C. C. , Crawford M. E. 
Published: December 2007

ABSTRACT
This paper describes the implementation of the expansion phase of the Wm. Berryhill Micellar-polymer flood. Stages in the injection processes and related problems are presented in chronological order. When developments in the pilot project dictated changes in the expansion, the pilot experience is discussed in detail.
In 1979, a pilot micellar polymer project was initiated in the Glennpool Field southwest of Tulsa, Oklahoma, on the Wm. Berryhill lease. The 18 acre pilot project was maintained until September, 1983, injecting into the upper member of the Bartlesville (Glenn) sand. Field tests from observation wells prompted expansion of the flood in 1982 to the adjacent 92 acres of the lease and to include the Middle Glenn sand.
Since lithology plays an important role in the flood behavior, the case history is prefaced by a geological review and reservoir characterization.
While the pilot production response indicates the flood to be a viable process, the expansion is an on-going project with final results yet to be determined. The flood is currently in the polymer phase, which will continue through May, 1987.
Fractured Water-Injection Wells: A Pressure Falloff Test for Determining Fracture Dimensions
Authors: Koning E. J. L. , Niko H. 
Published: December 2007

Abstract
Pressure transient theory for a water-injection well in the presence of a closing fracture and a discontinuity in fluid mobility is developed in elliptical coordinates. Solutions are obtained using the Laplace transform and numerical inversion. From the results it is concluded that a pressure fall-off test with a closing fracture, in principle provides three different methods for determining the fracture length. The first method is based on rock mechanical principles only. The second method makes use of formation linear flow. The third method analyses the transition of the pressure transient from the inner fluid region to the outer region in conjunction with a heat or volume balance. If more than one method is applicable consistent results should give a reliable estimate of the fracture length. The in-situ horizontal rock stress can also be determined from the test. It is equal to the pressure at which the closing of the fracture is observed.
Improved Lithology and Hydrocarbon Saturation Determination Using the Gamma Spectrometry Log
Authors: McGuire J. A. , Rogers L. T. , Watson J. T. 
Published: December 2007

ABSTRACT
Many papers have been written describing the theory and interpretation models of the GST* gamma spectrometry tool. This paper presents actual field examples where GST interpretation techniques were used to improve lithology identification and pore-fluid saturation determination. Examples are of varied geographic locations and reservoir conditions.
Sand Transport Experiments in Thin Fluids
Authors: Medlin W. L. , Sexton J. H. , Zumwalt G. L. 
Published: December 2007

ABSTRACT
Computer-controlled experiments were conducted by flowing thin, sand-laden fluid through a long lucite slot model. An optical absorption method was used to obtain computer-generated sand density profiles at a distance far from the slot entrance. Profiles were obtained at various flow rates, injected sand concentrations, and fluid viscosities. These were combined with visual observations from filmed records to investigate the three observed transport mechanisms, bed load, turbulence, and viscous drag. The experimental results were used to test theoretical predictions related to these mechanisms. We find good agreement between theory and experiment. We show that viscous drag is the only important transport mechanism under field conditions. Bed load transport is important in 1aboratory-scale experiments where it can produce equilibrium settled bank heights. But it is unimportant on the scale of field treatments because it does not scale up with slot height. Turbulence contributes little to sand transport under almost any condition. This means there is no transport mechanism for producing equilibrium banks in field treatments. Only viscous drag is left as the dominant transport mechanism in field treatments. This conclusion is examined in the light of large frac treatments using slick water. It is hard to account for the large quantities of sand carried in these treatments by viscous drag alone. This suggests the existence of a fourth mechanism which does not show up in fixed width slot flow experiments. Other possible mechanisms are considered including avalanche effects associated with a growing crack width.
Technically Recoverable Devonian Shale Gas in Ohio, West Virginia, and Kentucky
Authors: Kuuskraa V. A. , Sedwick K. , Yost A. B. 
Published: December 2007

ABSTRACT
Large volumes of natural gas may be technically recoverable from the Devonian shales of Kentucky, Ohio, and West Virginia. The technically recoverable gas from the Huron, Rhinestreet, Cleveland, and Marcellus intervals is estimated to range from 26 Tcf to 82 Tcf, depending on the success of new gas extraction technologies and practices. The total estimated in-place Devonian shale gas of this tri-state area is 394 Tcf. While much of the resource is in the Huron shale interval, significant portions are located in other thinner, yet organically rich, shale units that have experienced less development to date. This study represents the most current appraisal of Appalachian Devonian shale gas potential, and serves as an update of the 1980 National Petroleum Council work for this tri-state area.
Individualized Fracturing Treatment Design Benefits Clinton Sands
Authors: Mack D. J. , Mason R. A. 
Published: December 2007

ABSTRACT
Significant advancements have been made in the past few years in the areas of vertical fracture growth determination and treatment design. Techniques have been developed that use changes in the bottom hole treating pressure to describe fracture growth. In addition, open hole logs are available which will allow for the determination of vertical growth boundaries as a function of the increase in the bottom hole treating pressure.
A series of six wells have been drilled and fractured in the Clinton Formation of Northeast Ohio. Three of the wells utilized frac height logs for pressure boundary determination, while interpolation techniques were used on the other three. Fracture treatments were then designed for each individual well based on the rock properties of that well. The primary consideration in each design was vertical containment of the fracture and the placement of an effective proppant pack across the productive zone. By doing this, the productivity of the well will be increased.
The treatments were then performed and bottom hole treating pressure either calculated or monitored This pressure analysis has indicated fracture containment within the design boundaries.
This paper will discuss the treatment design procedure and results of the bottom hole treating pressure analysis. In addition, an explanation for the general lack of effectiveness of cross-linked and foamed treatment in the study area will be presented.
Geometry Determination for Multi-Stage Acidizing Treatments With or Without Viscous Preflush
Authors: Lee W. S. 
Published: December 2007

ABSTRACT
In recent years, significant progress has been made in the determination of fracture geometry. However, most effort is geared toward massive hydraulic fracturing treatments with proppants. Little progress has been made in the determination of fracture geometry especially for acidizing treatments.
This paper presents a method of determining fracture geometry for fracture acidizing treatment. The fracturing fluids used in an acidizing treatment are classified into four stages: preflush, viscous preflush, acid and overflush, each with different rheological properties. If viscous preflush is not used, relative positions of all fluids together with the resulting geometry are determined simultaneously based on the assumption that fluid pumped at a later time is unable to overtake fluid pumped at earlier time. If viscous preflush is used, relative positions of all fluids, together with the resulting geometry, are determined simultaneously allowing the possibility that acid and overflush can tunnel through and even completly overtake the viscous preflush pumped ahead of acid. Before the acid over takes the viscous preflush, the advancement of acid inside the fracture is rapid, and the acid creates an effective etching pattern. Once the acid overtakes the viscous preflush, its advancement slows down resulting in less effective etching pattern. An optimum design would most likely be the one where live acid barely overtakes the viscous preflush.
Two examples will demonstrate the effective use of this method for better acidizing design.
Development of a Multipurpose Numerical Model
Authors: Bilgesu H. I. , Ertekin T. 
Published: December 2007

ABSTRACT
A multi-purpose model is developed for simulating primary, secondary, and some of the tertiary recovery processes. The simulator models the isothermal flow of oil, water, and gas in porous media in two dimensions using either rectangular or radial coordinates.
Initially, partial differential equations describing the fluid flow are approximated using finite difference technique and the resulting system of equations are solved simultaneously via alternating direction implicit procedure. The transmissibilities are calculated using explicit, semi-implicit or fully implicit formulations. Although block centered grids are used for rectangular system, a mesh centered grid is employed in the case of radial system which yields in better representation of the well block pressures. Injected fluids are tracked separately but they are accounted for within all phases using mixing parameters that empirically predict the incomplete mixing within a block. In the case of polymer injection, the modified Blake-Kozeny4 equation is used in the representation of the viscoelastic behavior of the injected fluid in the pseudoplastic region. The stripping of polymer from the injected fluid due to adsorption is represented as a function of polymer and rock properties.
A fully implicit well formulation is used where well block pressure was solved simultaneously. Multiple wells with different injection and production schemes are included in the model. In the case of rectangular coordinates, an infinite conductivity fracture is coupled with the well block.
An automatic time step selector is implemented to reduce the time truncation errors as well as reducing the computational costs. The property package used different techniques such as linear interpolation, least squares, or cubic splines for predicting fluid properties or the user supplied functions are used.
The simulator is tested using published data for several options against existing models and results are found to be in good agreement.
Oil Development Strategy in an Uncertain Market
Authors: Ausman J M 
Published: December 2007

ABSTRACT
This paper contains observations about crude oil price forecasts and the way oil companies respond to oil price uncertainty. The industry is shown to act as though current oil prices are a good indicator of future prices. Industry earnings are shown to be less sensitive to low oil prices than might be expected. Strategically, it is important to recognize the inefficiency of the industry responding to rising and falling oil prices with "on/off" spending patterns.
Astute Basin Evaluation, Key to Economic Success in Hard Times
Authors: Newman Peter V 
Published: December 2007

ABSTRACT
Intelligent basin evaluation, leading to identification of those basins with the greatest exploration potential, is a critically important element of the exploration process. This is especially true during times of crude price weakening, when finding costs take on somewhat greater significance. Proper basin choice is also one of the few ways in which you can gain a substantial advantage over the competition – your staff and technology are probably not much better than those of your major competitors, but it may be possible to explore a considerably more prospectize suite of basins. For these reasons, the basin selection process should be taken very seriously, with as much thought and effort going into it as into the other major segments of the exploration program.
This talk will discuss the factors that are important to basin evaluation, both geologic and nan-geologic. Non-geologic factors include not only political and economic issues, but company-specific elements that relate to company size, resource base, and operating philosophy. With geologic factors, the emphasis will be an identifying the relatively few that are critical and then predicting where those factors can be favorably combined. Modern basin classification concepts will be an aid here, especially in virgin basins.
The thesis will be advanced that, in developed basins, an entire data set is being generally ignored that could significantly improve the accuracy and quality of the basin-evaluation process. It appears that too often there is a tendency to seek out innovative exploration breakthroughs without first having utilized all the pertinent data available. In terms of cost-effectiveness and realistic results, putting these data to use may be more productive than searching for a breakthrough.
The paper will close with an example from South-east Asia of a simple but highly successful basin analysis exercise.
Impulsive Pressure of Breaking Wave on Piles
Authors: Tanimoto K , Takahashi S , Kaneko T , Shiota K 
Published: December 2007

ABSTRACT
Characteristics of impulsive pressure on inclined circular piles exerted by a breaking wave were evaluated experimentally. The experiment was conducted on a model pile, which was inclined from 0° to +30° on a 1:10 bottom slope. Time histories and distributions of the impulsive pressure were observed using ten pressure transducers on the pile surface.