bluuebunny/crossref_metadata_2025_split huggingface dataset:
The Calculation of Waterflood Recovery From Steady-State Relative Permeability Data
Authors: Richardson J.G. 
Published: December 2007

Abstract
The performance of laboratory water floods is compared with the flooding behavior calculated by the Buckley-Leverett techniques from steady-state relative permeability-saturation relations. Both the steady-state and unsteady-state experiments were conducted on the same sand-packed column. Relative permeabilities were calculated by the Welge technique from the unsteady-state waterflooding displacement experiments and compared with those measured by steady-state techniques. An evaluation of the various calculation procedures was made. It was demonstrated that steady-state relative permeabilities could be used to calculate waterflood performance.

Introduction
To calculate the waterflooding behavior of a given reservoir, relative permeability-saturation relations of the reservoir rack are required. These relative permeabilities are commonly measured on care samples by steady-state experiments such as the Penn State technique. The relative permeabilities obtained in steady-state experiments are calculated from oil and gas flow rates and pressure drops measured under conditions of equilibrium distribution of oil and water in the pore spaces with slow approach to equilibrium. On the other hand, in water floods the water saturation at a given point changes rapidly with time as the flood front passes.
Extensive research has shown that the steady-state relative permeabilities to oil and water are independent of the rate of flow and the fluid viscosities. Research has also demonstrated that the waterflooding performance of homogeneous sands uniformly contacted by water is independent of rate when capillary pressure gradients, which are important in short laboratory columns, are made negligible. However, there is little experimental data in the literature comparing relative permeabilities calculated from steady-state flow experiments with those calculated from flooding experiments.
In this paper, the production data of two water floods and the relative permeabilities calculated from a series of steady-state experiments on an unconsolidated sand column are presented along with the comparisons calculated by the Buckley-Leverett and by the Welge techniques. The purpose of this study was to determine if steady-state relative permeabilities could be used to predict the waterflooding performance. This study also permitted an evaluation of the Buckley-Leverett and Welge calculation procedures and allowed an insight into the nature of microscopic displacement of oil by water.
Influence of Very Low Interfacial Tensions on Relative Permeability
Authors: Bardon Charles , Longeron D. G. 
Published: December 2007

Abstract
Laboratory studies have been conducted to determine the influence of the composition of gas and oil phases on the parameters involved in the description of two-phase flow in porous media when the compositions of the phases vary over a wide range. Relative permeabilities to gas and oil were determined under high pressure and temperature for binary systems (methane/n-heptane, methane/n-decane, etc.), leading to very wide variations of the interfacial tensions values. Investigations were focused specifically on mixtures involving low interfacial tensions, down to 0.001 mN/m.
This study has shown that residual oil saturations and relative permeabilities determined from the displacement tests with a filtration velocity of about 20 cm/hr are affected strongly by interfacial tension, especially when it is lower than 10−2 mN/m.
Future Outlook of Petroleum in the World
Authors: Reistle Carl E. 
Published: December 2007

Introduction
The decade since World War II has, in many ways, been one of the most eventful periods of world history. For one thing, the pattern of industrial and political development predicted at the end of World War II is quite different from that which has actually evolved. Many thoughtful people believed that we were close to attaining real world peace and that we would experience the historical pattern of an economic recession following a great war. Of course, neither of these estimates has proved to be correct. The world has suffered several minor wars, that is, minor compared to the World Wars, and certainly there are conditions and forces throughout the world today that constitute a real threat to peace. On the economic side, the forecasters of a major recession have proved to be especially incorrect. There has never been a similar period of time in world history in which economic growth has approach that of these past 10 years.
In the forefront of this phenomenal growth has been a tremendous increase in demand for petroleum products. The purpose of this paper is to attempt to describe this increase in demand, explain how the world oil industry has met the challenge, and speculate a bit about the industry's future.

The Growth in Demand for Petroleum Products
Fig. 1 is a bar-graph on which the consumption of petroleum products by geographic areas for the first year following World War II (1946) is compared with that of 1955. The total world demand has more than doubled in this short period-from 7.8 million B/D (2.84 billion bbl per year) in 1946 to 16.1 million B/D (5.86 billion bbl per year) in 1955. You will notice that, although the United States continues to be the principal market for petroleum products, its rate of increased demand has not been nearly as great as that of other areas, particularly Europe. Another interesting comparison between 1946 and 1955 is the relative demand for the principal products produced from petroleum. Fig. 2 provides a comparison of the world's consumption of gasoline, kerosene, distillate fuel, and residual fuel for 1946 and 1955 in the free world. The greatest increase in demand has been for gasoline and distillate fuels.
The Application of Fractional Flow Theory to Enhanced Oil Recovery
Authors: Pope Gary A. 
Published: December 2007

AbstractClassical fractional flow theory is generalized, starting with the Buckley-Leverett theory for waterflooding. The mathematics are based on the method of characteristics. The physics and how the problems are treated are analogous to the multicomponent adsorption problem of chromatography; thus, the methods of Helfferich apply. Enhanced oil-recovery (EOR) cases considered are polymer flooding, carbonated waterflooding, hot waterflooding, hydrocarbon miscible flooding, low-tension flooding, and micellar/polymer flooding. The alcohol flooding, enriched gas, and carbon dioxide cases are analogous in many respects to the micellar/polymer case. Finally, three-phase flow problems are treated. Three-phase flow occurs in a variety of EOR processes.
A Statistical Study of Some Waterflood Parameters
Authors: Felsenthal Martin 
Published: December 2007

Important parameters needed to forecast waterflood reserves and rates are residual oil saturation (Sor) in the swept zone, relative permeability to injection water (krw), and ratio of peak oil rate to injection rate. To investigate the statistical distribution of these parameters, a review was conducted of laboratory core test results and field performance data.

Residual Oil Saturation in the Swept Zone
Tables 1 and 2 summarize data obtained from relative permeability tests on numerous samples. About 10% of these data came from the literature and the remainder came from unpublished reports for fields in Canada, Libya, the U.K. sector of the North Sea, and fields in the following states: California, Colorado, Illinois, Indiana, Kansas, Mississippi, Montana, Oklahoma, Pennsylvania, Texas, Utah, and Wyoming. Fig. 1 illustrates the distribution of residual oil saturations at the end of laboratory oil/water relative permeability tests. The core test samples were generally small - typically about 7/8-in. (22.3-mm) in diameter. Because of the small sample size, many features of carbonate rock (such as vugs, solution channels, and fractures) were underrepresented or not represented at all. Thus, results shown essentially reflect the intercrystalline porosity. Results indicate that Sor in the swept porosity. Results indicate that Sor in the swept portion of the reservoir is slightly lower in the matrix portion of the reservoir is slightly lower in the matrix of carbonate rocks than in sandstones. A statistical
TABLE 1 - WATERFLOOD RESIDUAL OIL SATURATIONS MEASURED IN CORE TEST SAMPLES
CarbonateSandstone Rock
Mean Average Sor, % pore space 27.7 26.2 Median average Sor, % porespace 26.6 25.2 Number of core samples tested 316 108 Number of source reservoirs 75 20 Standard deviation, % pore space 8.76 8.84
test (t test) showed that the difference is significant at a confidence limit of 90%.Attempts were made to correlate Sor with either KAIR or porosity for each lithology type. These attempts were unsuccessful; that is, the coefficients of correlation were too low to develop significant general correlation equations. Results were as follows:
Coefficients of Correlation (r)Sor vs ln KAIR Sor vs Porosity
Sandstone 0.077 0.073 Carbonate rock 0.209 0.246
Relative Permeability to Water at Residual Oil Saturation
Fig. 2 shows a correlation of krw at Sor with KAIR for a turbidite formation of Repettian (early Pliocene) age from California. The correlation coefficient equaled 0.57, indicating that the correlation shown was significant at a confidence level of 95%.
TABLE 2 - EFFECT OF LITHOLOGY AND KAIR ON THE END POINTS OF OIL/WATER RELATIVE PERMEABILITY CURVES
Permeability group: Low Medium High Permeability group: Low Medium High Range of KAIR, md: (1 to 10) (11 to 100) (101 to 2,000)
Sandstone
Median krw at Sor 0.065 0.133 0.256 Median krw at Sor 0.033 0.095 0.210 Number of coresamples tested 30 213 143
Carbonate Rock
Median krw at Sor 0.211 0.357 0.492 Median krw at Sor 0.179 0.303 0.428 Number of coresamples tested 33 45 24
P. 1303
A New Instrument for Measuring Bulk and Grain Volumes
Authors: Russell William L. 
Published: December 2007

Abstract
A new instrument for measuring bulk and grain volumes is described, and compared in accuracy with two modifications of Nutting's method. All three methods are reasonably fast, and in all three the probable error in the determinations of bulk volume can be kept down to about 0.1 to 0.2 per cent.

Introduction
The new pycnometer described in this paper is designed to give speed without sacrificing accuracy. Some time ago Russell described a somewhat similar apparatus; however, the instrument described in the present paper is more accurate. Nutting designed the pycnometer shown in Fig. 1 (A and B), and Pirson has shown points like those of Fig. 1-D. The procedure described in this paper for using Nutting's pycnometer has been modified from that used by Nutting.

Choice of Liquids
The best liquids for measuring grain volumes are hydrocarbons or chlorinated hydrocarbons which evaporate slowly. Trimethylbenzene or mesitylene, triethylbenzine, carbon tetrachloride, and tertalin have been used for this purpose. Any of these liquids or mercury may be used for measuring bulk volume.

Preventing Errors Due to Invasion of Liquid
Errors due to the invasion of the porous, permeable bulk samples by the liquid of measurement may be prevented or greatly reduced by using mercury, by applying an impervous coating, or by soaking the bulk samples in the liquid of measurement until bubbles cease issuing from them. Errors are produced only by the invasion of the samples which occurs between the movement when the samples are weighed in air and the moment the weight of liquid displayed by the sample in the pycnometers is determined. No error is produced by varying degrees of filling of the pore space of the samples by the liquid of measurement.
Representing Wells in Numerical Reservoir Simulation: Part 1 – Theory
Authors: Williamson Alexander S. , Chappelear John E. 
Published: December 2007

Abstract
A reservoir simulation system uses an analytical model to represent flow within a grid block as it enters or leaves a well. This model is called a well model. We give a description here of the theoretical background of a well model, including how the sandface pressure and saturation boundary conditions can be calculated and how the well boundary itself can be replaced (approximately) by a source function. This paper and the following companion paper, SPE 9770, present a unified viewpoint of material, some of which may be already familiar to simulator developers.
A Simple and Accurate Description of Nonlinear Fluid Leakoff in High-Permeability Fracturing
Authors: Hoek P. J. van den 
Published: December 2007

Summary
Fluid leakoff in hydraulic fracturing is conventionally described using the well-known linear (Carter) model. Although this works well in low-permeability formations, the linear leakoff assumption may lead to sometimes significant overestimation of fracture dimensions in medium- to high-permeability formations. At present, no methodology is available that allows an easy estimation of the impact of nonlinear fluid leakoff on fracture dimensions and on pressure decline (minifracture) analysis. This paper aims to resolve that deficiency.
An exact numerical solution is presented to the fully transient elliptical fluid-flow equation around a propagating hydraulic fracture for arbitrary pump rate(s). In addition, a simple analytical formula for elliptical leakoff rate is presented that is shown to yield an excellent approximation of the numerical results, both during fracture growth and after shut-in. This formula can be easily incorporated into any existing hydraulic fracture model, and it is applicable over the entire range of fluid leakoff rates (i.e., from low-permeability fracture stimulation on one hand to high-permeability waterflood fracturing on the other).
The above result is applied to a variety of hydraulic fracturing field examples to explore the limits of the linear (Carter) leakoff assumption, both in pressure-decline analysis of minifractures and in fracture design. It is shown that in frac-packing and high-perm cuttings reinjection (CRI), the linear leakoff assumption may lead up to a tenfold overestimation of fracture dimensions.
Conversely, incorporating nonlinear leakoff in the minifracture interpretation of high-permeability fractures will yield larger minifracture radii and lower total leakoff coefficients. This will result in more aggressive pump schedules.
Transport Properties of Porous Media Reconstructed From Thin-Sections
Authors: Hidajat I. , Rastogi A. , Singh M. , Mohanty K. K. 
Published: December 2007

Summary
The objective of this work is to predict transport properties within any complex porous medium from its 2D microimage. 3D porous media are generated that have the same porosity, autocorrelation, chord length distribution, and lineal path function as a given 2D microimage of a medium. The properties of the reconstructed media are compared with those of the original media. A pore skeleton and Euclidean distance map are determined for the 3D pore-space from which body radius, throat radius, and connectivity distributions are extracted. This network structure is used in calculation of transport properties. Specific surface area is estimated accurately. Permeability and formation factor are estimated approximately. The correlations between adjacent pore bodies and throats are identified.
Horizontal Injectors Rejuvenate Mature Miscible Flood—South Swan Hills Field
Authors: Edwards K.A. , Anderson B. , Reavie B. 
Published: December 2007

Summary
The South Swan Hills pool, located in northwest Alberta, Canada, is a carbonate reef with an original oil in place (OOIP) of approximately 850 million bbl. Waterflooding began in 1963, and a staged hydrocarbon miscible flood covering most of the field began in 1973. Solvent injection in the main miscible flood was terminated in 1989, and chase gas injection ceased in 1998. In 1994, however, solvent injection was reinitiated into a single pattern in the reef margin area of the field using a horizontal injector and reduced well spacing. The reef margin is an area of thick, stacked pay that experienced high gravity override during the original miscible flood. The horizontal injector was placed at the base of the reef margin to minimize the effects of gravity override and to maximize sweep efficiency. Four patterns have been developed to date. The two earliest patterns have now completed solvent injection and are on chase waterflood. Both patterns are projected to recover almost 1 million bbl of incremental oil per pattern (more than 10% of pattern OOIP) from areas that were part of the original miscible-flood project.
This paper covers the development of the original miscible flood, the redevelopment of the reef margin area using horizontal miscible injectors, and the performance of the four patterns implemented to date. The geological and performance factors that made this redevelopment successful, and their impact on field production, are discussed. Finally, plans for future development of this mature field are presented.
Takula Field: Data Acquisition, Interpretation, and Integration for improved Simulation and Reservoir Management
Authors: King G. R. , David W. , Tokar T. , Pape W. , Newton S. K. , Wadowsky J. , Williams M. A. , Murdoch R. , Humphrey M. 
Published: December 2007

Summary
This paper discusses the integration of dynamic reservoir data at the flow-unit scale into the reservoir management and reservoir simulation efforts of the Takula field. The Takula field is currently the most prolific oil field in the Republic of Angola.
Quantifying the Economic Impact of 4D Seismic Projects
Authors: Waggoner J. R. 
Published: December 2007

Summary
Time-lapse 3D, or 4D, seismic imaging has been analyzed by the industry for more than a decade, with a growing number of successful cases being reported in the literature. Two of the most recent 4D case studies1 reporting success are Draugen in the Norwegian North Sea and Gannet-C on the U.K. continental shelf. Both have been technical successes, providing good images of time-lapse changes in the reservoir. These 4D results have changed drilling locations and reduced the risk associated with costly field-development decisions. (Note: from this point forward, "4D" is used to refer to time-lapse seismic imaging.)
The focus of this paper is quantifying the economic impact of 4D. After reviewing some ways that 4D can impact reservoir management, an economic model is developed that can quantify that impact. The decision tree model uses Bayes' theorem to compute the modified probabilities resulting from 4D. The model indicates that, for the case of drilling an infill well, 4D information adds considerable value to the project, even considering that the 4D information is not perfect.
Predicting Reservoir Fluid Phase and Volumetric Behavior From Samples Contaminated With Oil-Based Mud
Authors: Gozalpour F. , Danesh A. , Tehrani D. -H. , Todd A. C. , Tohidi B. 
Published: December 2007

SummaryThe impact of sample contamination with oil-based mud filtrate on phase behavior and properties of different types of reservoir fluids, including gas condensate and volatile oil, has been investigated. Two simple methods are used to determine the uncontaminated fluid composition from contaminated samples. The capability of the methods is demonstrated against highly contaminated samples.An equation-of-state (EOS)-based method also has been developed to predict the phase and volumetric properties of the retrieved composition. The method determines the required parameters of the EOS for the uncontaminated fluid using the developed phase-behavior models from contaminated-sample data. The method has been examined against experimental data of different types of reservoir fluids with successful results.
Safe Disposal of One Million Barrels of NORM in Louisiana Through Slurry Fracture Injection
Authors: Reed A. C. , Mathews J. L. , Bruno M. S. , Olmstead S. E. 
Published: December 2007

Summary
During the past 50 years, storage pits and adjacent land around the Bay Marchand facility near Port Fourchon, Louisiana, had accumulated large deposits of nonhazardous drilling and production waste containing naturally occurring radioactive material (NORM). This material primarily included drill cuttings, drilling mud, produced sand, salt water, pipe scale, crude oil, and precipitates. To remediate this site, the operator chose to reinject the material into the deep subsurface through on-site slurry fracture injection (SFI). This process provided greater environmental security compared to alternative surface pit or landfill disposal and at a much lower cost than off-site transport and disposal options.
More than 1 million barrels of pit soil and canal bottoms were safely disposed into a single well during 2 years of injection that concluded in March 2000. Solid waste was mixed with water to create a slurry and injected downhole at greater than the formation parting pressure into a weakly consolidated sandstone formation at depths from 4,400 to 5,000 ft. Injection operations were episodic, generally taking place for 11 hours per day, 5 days per week. This allowed the formation pressure to decline each day to the initial reservoir pressure. The project was designed and extensively monitored to maintain and verify containment within the permitted interval. Downhole pressure was continuously monitored, allowing analysis of daily falloff pressure. Waste containment was confirmed through a combination of shut-in pressure analysis and periodic step-rate tests, gamma logs, and temperature surveys.
In addition to the improved environmental protection provided by this technology, the on-site operation was a fraction of the off-site disposal costs. This paper describes the project design and permitting, injection operations, containment monitoring and analysis, and project economics.
Pressure-While-Drilling Measurements To Solve Extended-Reach Drilling Problems on Alaska's North Slope
Authors: Mallary C. R. , Varco Martin , Quinn D'Arcy 
Published: December 2007

SummaryExtended-reach drilling (ERD) is playing an important role in the economic development of Alaska's North Slope oil reserves. For some ERD wells, careful well planning and existing drilling practices are sufficient to avoid problems, such as wellbore instability, lost circulation, and stuck pipe. However, recent Alaskan experience has shown that as well step-outs increase, some operational practices developed on conventional wells are inadequate to successfully deliver cost-effective ERD wells. On these wells, careful planning alone cannot always prevent costly drilling problems.The ability to analyze downhole annular pressures with pressure-while-drilling (PWD) data has proven invaluable to the drilling engineer. The value of this information is not fully realized, however, until it is put in the hands of the rig operator, who can act on it in real time. This paper examines the impact PWD measurements have made in recent Alaska ERD wells and focuses on both planning and operational uses. Field data are presented from problem and nonproblem wells to underscore successful and unsuccessful operational practices. The importance of rig-site training in equivalent-circulating-density (ECD) management and the linkage to drilling, circulating, and tripping practices are developed.