bluuebunny/crossref_metadata_2025_split huggingface dataset:
Effects of Petroleum Tax Design Upon Exploration and Development
Authors: Stauffer Thomas R. , Gault John 
Published: December 2007

ABSTRACT
The principle that conventional schemes for taxing petroleum or mineral resources are "inefficient" is illustrated using simulation calculations tested against an "ideal" system.
Inefficiency is defined as the relative success in maximizing expected government revenues from the resources. Most systems fail because: 1) they leave oil in limbo, i.e. unproduced because of excessive fiscal burden; or 2) they unnecessarily increase the variance in the explorationist's rate of return by undertaxing large fields and overtaxing smaller but infra-marginal fields. This increases his discount rate and reduces taxable surplus.
An "ideal" tax system is specified which maximizes government revenues while minimizing risk to the operator. Two criteria are developed: 1) the tax falls to zero on fields which yield only the minimum necessary rate of return ("marginal" fields); and 2) the after-tax present value of all fields is the same for all fields above a threshhold size.
In particular, marginal fields, while contributing little to expected values, do contribute to reducing variance and hence risk praemia by distributing the exploration costs over a higher probability of successful outcomes.
Well Log Evaluation Study of Middle East Oil Fields
Authors: Youash Younathan Y. , Halyburton Rodney V. , Mukhopodhyay Amitabha , Biswas Partha B. 
Published: December 2007

ABSTRACT
In a well log evaluation of a field study, normalization of porosity logs is often necessary to get reliable results. The effect of heavy minerals should be accounted for in calculating porosity from density logs realistically. Porosity variation is mainly dependent on shaliness. The bulk volume water concept is useful in delineating zones of irreducible saturation and transition zones. For a particular rock group, water saturation is related to the resistivity by a simple hyperbolic function. The TDT log may be used in monitoring water movement and water fingering. Analog plots of results of quantitative log interpretation are useful in stratigraphic subdivision and correlation.
Optimized Drilling in Remote Areas
Authors: Deerhake William F. , Khalaf Fouad , Seehafer John A. 
Published: December 2007

ABSTRACT
Corporate Computer Centers and timesharing networks have provided the drilling industry with access to a variety of applications software associated with the optimization of drilling operations. But, even with today's worldwide communications networks there are still areas where remote access to such technology is not possible.
The purpose of this paper is to show the experience of the Gulf of Suez Petroleum Company (GUPCO), a joint venture company between Amoco International Oil Company and Egyptian General Petroleum Company, in utilizing mini-computers to optimize its remote drilling operations and assist in the storage and retrieval of drilling data.
Use of Complex Weak Acid in Canyon sand Stimulation
Authors: Armendariz Victor M. , Barringer David K. 
Published: December 2007

ABSTRACT
One of the primary concerns in completion practices for the Canyon Sand in Sterling, Schleicher, Sutton and Crockett Counties has been to balance possible formation damage with completion costs. The low productivity, and until very recently, the low gas prices for this area has made the use of "exotic" fracturing treatments very difficult to justify. The fluids were normally a gelled water or gelled weak acid system, often used with CO2. In those instances where the treatments are performed via tubing, low injection rates often contributed to screenouts. The recent advent of cross linked water based fluids and more effective clay stabilizers has reduced both the screenout problems and formation damage. Within the last 8-12 months, a complexed weak acid system has been developed which has demonstrated a combination of most of the advantages of the other systems with very few disadvantages.
The ability to transport sand out to the drainage boundary is the ideal stimulation practice for almost any "tight" sand.1 This idealized treatment, though, is often not economically justifiable due to the inefficient nature of the fracture fluid, especially the earlier fluids used in this area. In this paper, we will investigate the theoretical and practical aspects of pumping a complexed weak acid system. This system possesses a large number of the desired characteristics for use in the Canyon Sand -- high viscosity, low friction loss, low pH compatibility with CO2, compatibility with clay stabilizers and fluorocarbon surfactants, low fluid loss, and excellent sand transport properties.
New Completion System Eliminates Remedial Squeeze Cementing for Zone Isolation
Authors: Oliver James E. 
Published: December 2007

ABSTRACT
A new completion system has been developed which provides permanent and positive zone isolation and eliminates the need for remedial squeeze cementing. This system utilizes one or more long external casing packers that are positioned across the completion interval and inflated with cement during the primary cementing operation. Packer inflation exerts a hydraulic centralizing force on the packer mandrel to center it in the borehole and surrounds it with uncontaminated cement. As the packing element expands, it conforms to borehole irregularities. After the cement sets and the casing is drilled out, the packer(s) is(are) perforated and the zone(s) completed using normal completion practices with assurance that vertical fluid migration, via the casing-wellbore annulus, into or out of the perforated interval, is prevented.
Generalized Welge Construction for Two-Phase Flow in Porous Media in System with Limited Miscibility
Authors: Helfferich F. G. 
Published: December 2007

ABSTRACT
The Welge construction to establish saturation profiles or histories in one-dimensional displacement of two completely immiscible phases in porous media is generalized for systems with limited miscibility of the two phases. The extension is applicable to any number of components, all of which may partition between the two phases. Instead of a diagram of fractional flow versus saturation of either phase in the conventional Welge construction, the extension uses a diagram of overall fractional flow versus overall volume fraction of an arbitrary component. The principle of construction remains the same. However, the different nature of the curve, in particular the discontinuities in slope, give rise to a more complex behavior. The various types of behavior which can occur in systems with S-shaped fractional flow curves within the two-phase region are discussed.
A New Concept In Acidizing Utilizing Chemical Retardation
Authors: Knox John A. , Lasater R.M. 
Published: December 2007

Publication Rights Reserved
This paper is to be presented at the 39th Annual Fall Meeting of the Society of Petroleum Engineers on Oct. 11–14, 1964, in Houston, Tex., and is considered the property of the Society of Petroleum Engineers. Permission to publish is hereby restricted to an abstract of not more than 300 words, with no illustrations, unless the paper is specifically released to the press by the Editor of JOURNAL OF PETROLEUM TECHNOLOGY or the Executive Secretary. Such abstract should contain conspicuous acknowledgment of where and by whom the paper is presented. Publication elsewhere after publication in JOURNAL OF PETROLEUM TECHNOLOGY or SOCIETY OF PETROLEUM ENGINEERS JOURNAL is granted on request, providing proper credit is given that publication and the original presentation of the paper.
Discussion of this paper is invited. Three copies of any discussion should be sent to the Society of Petroleum Engineers office. Such discussion may be presented at the above meeting and considered for publication in one of the two SPE magazines with the paper.

Abstract
Establishing a technique to compare the reaction times of various types of acid solutions on limestone was the first phase in the development of a new method for retarding acid. With a critical comparison available, the well known approaches could be more properly evaluated.
The limitations of the available methods of retardation became obvious and pointed out the necessity of finding a better way to retard acid.
For several years, the approach of chemically retarding acid solutions has been under consideration by the industry, but no practical economical system was found. With the development of a fairly rapid testing technique, which simulates bottom hole conditions, the chemical retardation of acid received increased effort and a highly efficient method resulted.
Reaction times, using the new system, of up to 3 hours at 200 degrees F on pure limestone formations have been observed. The effect of chemical type, temperature, pressure and surface area to volume ratio was studied.
A possible theory describing the mechanism for this type of retardation is discussed.

Introduction
Many thousands of research hours have been devoted to the problem of stimulating oil and gas wells with various types of acid over the last thirty years. Oil companies and service companies have shared the responsibility of studying both the methods of application and materials used in these applications in an effort to improve stimulation results.
For many years acidizing was the primary stimulation method for most well problems.
Clean Fluids Improve Completion Results
Authors: Rike J. L. , Pledger T. M. 
Published: December 2007

ABSTRACT
The preponderance of evidence shows that completion effectiveness, and especially well productivity, is directly related to the use of clean completion and workover fluids.
Even small amounts of solids (500 ppm) in completion and workover fluids can be enough to bridge in perforation tunnels, in channels behind pipe, and in gravel packs and in propped fractures. This plugging is responsible for many wells producing at 1085% of full potential; for multiple squeeze attempts so often necessary to successfully seal cement channels; and for sticking pipe during concentric tubing operations.
It is a widely held myth among industry operations personnel that plugg ng material is easily removed with reactive materials such as HF acid in the case of clay solids or HCl acid in the case of carbonate solids.
Tests and field experience indicate that significant increases in flow conductivity are obtained not only with clean fluids instead of muds and dirty fluids, but also when larger pressure differentials into the wellbore exist while perforating.
Injection Well Workover Program In The Levelland Field: A Case History
Authors: Wilkes James H. 
Published: December 2007

ABSTRACT
Sun Production Company performed a workover program in which 14 injection wells were selectively acidized to improve injection profiles. Sixty-four percent of the workovers were successful in improving vertical distribution of water injection. Increased oil production paid out the project in less than a year and raised the secondary reserves estimate by 657,000 bbls.
San Andres Reservoir Pressure Coring Project for Enhanced Oil Recovery Evaluation, Bennett Ranch Unit, Wasson Field, West Texas
Authors: Swift Terry E. , Goodrich John , Kumar Raj , McCoy R. L. 
Published: December 2007

ABSTRACT
During late 1979, Gruy Federal Inc., under contract to DOE, participated with the operator in pressure coring operations in Texas Pacific BRU No. 310, Bennett Ranch Unit, Wasson field, west Texas. The well was planned as part of a program to continue development of the waterflood unit on 20-acre spacing. In all, 26 cores were cut over a 210-foot interval of the San Andres dolomite. The cored interval extended some 50 feet below the estimated original oil-water contact, allowing evaluation of CO2 floodable oil saturation in the transition zone. The analysis of the pressure coring data has provided valuable information that could not have been obtained from conventional cores and/or logs.
Waterflood Residual Oil Saturation Technology Test In A Semi-Consolidated Sandstone Reservoir
Authors: Myal F. Richard , Wesson T. C. 
Published: December 2007

ABSTRACT
Gary Energy Corporation has conducted for the U.S. Department of Energy an evaluation of the technology available to measure residual oil saturation following waterflood secondary oil recovery processes in the Bell Creek Field, Powder River County, Montana.
This paper presents the results of ten stand alone tests conducted to determine waterflood residual oil saturation. The engineering techniques used in an attempt to determine the magnitude and distribution of the remaining oil saturation included pressure cores, conventional openhole logs, Carbon-Oxygen logs, Dielectric logs, the Nuclear Magnetism log, Thermal Decay Time logs and a Partitioning Tracer test.
Enhancing Employee Longevity: Diet and Exercise Strategies for Dealing With Obesity
Authors: Kuo W. H. 
Published: December 2007

Abstract
Obesity is the number one threat to workers' health in the 21st century. It is a contributing factor in many types of cancer and its sequelae make it the top culprit of employee disability. This paper offers medical research findings on appropriate diet and exercise regimens to ameliorate obesity and maintain appropriate body weight on a long-term basis.
Strain Relaxation Method for Predicting Hydraulic Fracture Azimuth From Oriented Core
Authors: Teufel Lawrence W. 
Published: December 2007

ABSTRACT
A reliable method of predicting the orientation of massive hydraulic fractures in low-permeability formations is of great importance to the gas industry. An accurate prediction of the fracture orientation would allow optimum well location and spacing for increased recoveries in a developing field. In order to predict the azimuth of a hydraulic fracture, it is necessary to know the direction of the minimum horizontal compressive stress, because a hydraulic fracture propagates perpendicular to this stress direction. In this study a strain relaxation technique is presented as a possible method of determining the directions and the ratio of the maximum and minimum horizontal strains (stresses) from oriented core, and thus predict the fracture orientation.
Use of Constant Pressure, Finite Capacity Type Curves for Performance Prediction of Fractured Wells in Low-Permeability Reservoirs
Authors: Thompson J. K. 
Published: December 2007

ABSTRACT
This paper describes the general use of previously published1 constant-pressure finite capacity type curves in predicting performance of fractured wells in low-permeability (&lt; 0.1 md) gas reservoirs. Several well case histories are presented illustrating the use of these "reciprocal dimensionless rate" type curves in matching and forecasting well performance in tight formations. The effect of certain physical factors on predictions are also briefly discussed.
The prediction method and case histories in this paper represent the use of a relatively simple but reliable technique for time-rating of tight formation reserves. The method illustrates hand calculations which are readily adaptable to basic computer programming for use by individuals or smaller companies who may not have access to more sophisticated MHF simulators or for straightforward, single-phase flow examples where the time and expense of a MHF simulator may not be warranted.
Advances in Evaluating Gas Well Deliverability Using Variable Rate Tests Under Non-Darcy Flow
Authors: Henri Pascal 
Published: December 2007

ABSTRACTSeveral new mathematical models which simultaneously incorporate the effects of non-Darcy flow in formation and variable flow rate have been developed and discussed with respect to the determination of fracture and reservoir properties using tests of pressure drawdown. From these models, an appropriate approach for determining the permeability, non-Darcy flow coefficient and skin factor using the prefracture tests of short duration was shown. Another proper approach for analysing the postfracture tests was also presented. The effects of non-Darcy flow and variable rate have been emphasized, and significant progress in the interpretation of single-point variable drawdown test was made. The efficiency of this new approach is illustrated by means of a real field example.
Tight Gas Sandstone Channel Continuity and Directivity, Upper Cretaceous and Paleocene, Greater Green River Basin, Wyoming
Authors: Hodges Lance T. , Knutson Carroll F. 
Published: December 2007

ABSTRACT
In order to provide background characterization information that might help achieve increased gas production from tight gas sands in the Greater Green River Basin in Wyoming, we studied outcrops of rocks in three areas: Rock Springs Uplift, Hoback Basin, and Cretaceous Mountain. Formations studied were: Paleocene (Ft. Union equivalent), Hoback, Lance, Mesaverde (Hoback Basin), Ericson, and Rock Springs. Besides photographic and base and compass surveys of channel beds in these areas, detailed measurements were made on 25 channels. About 80 tabular or parallel inclined foreset, hummocky and trough cross beds in each channel were selected for geometric and orientation measurement. The most comprehensive data was obtained on the Rock Springs Formation.
Heights of cross beds varied from 0.1 feet to several feet. Median heights ranged from 0.2 feet to 1.2 feet. For parallel inclined beds, Lance and Paleocene rocks have similar height distributions, as do Rock Springs and Hoback Formations. Ericson units have the largest cross beds. Trough heights for Paleocene and Hoback rocks are usually less than Rock Springs rocks. The Lance Formation has the smallest troughs (height and width). Dip angle distributions of parallel inclined beds are very similar for the Rock Springs, Hoback, Ericson, and Lance Formations. Paleocene and Mesaverde parallel inclined beds have larger dip angles.
Channel thickness varies from Lance, with an 8 foot median, to Ericson, with a median of 19 feet. Channel continuity was difficult to determine, but Rock Springs and Ericson have the longest observed lengths, frequently more than 1 mile. Channel paleocurrent directions were calculated from cross bed data. Nearby channels showed some similar directions.
The channels studied in the Green River Basin generally have good continuity and fair directivity. A high resolution dipmeter log could be used to record cross bed dip directions, which could be used to roughly determine the sandstone unit trends. This information could be used to help design better fracture jobs, and thus help increase gas productivity.
Resource Identification by Principal Components Analysis as Applied to Low-Permeability Reservoirs
Authors: Bialobok Stephanie J. 
Published: December 2007

ABSTRACT
A preliminary step to determine the amount of recoverable reserves in a hydrocarbon reservoir may be the reconstruction of the depositional environment of the basin. Many of the major basins of the U.S. have similar origins as extensive inland seas where organic debris accumulated and hydrocarbons were generated as the sediments were compacted. If hydrocarbon-producing basins are essentially similar, then a technique for identifying the resource potential of one basin may be applicable to others.
A statistical technique known as Principal Components Analysis was used to reduce the dimensionality of a mineralogical data set from five cores of Devonian shale, a low-permeability source bed reservoir in the Appalachian Basin. The data set was reduced to three-dimensional arrays by the calculations of three hypothetical variables, the principal components, from the original variables. The resultant principal components, which explained 93 percent of the variation within the data set, were plotted graphically against the stratigraphy of the cores in an attempt to determine the extent of the basin. It is conceivable that this technique would be useful in other low-permeability reservoirs with equally satisfying results.
A Model for the High Frequency Response of Reservoir Rocks and its Implications on Dielectric Log Interpretation
Authors: Lysne Peter 
Published: December 2007

ABSTRACT
The electrical response of wet reservoir rocks is primarily due to the motion of ions within the pore structure. Electric fields pin some ions at matrix-fluid interfaces, and they contribute to the bulk dielectric properties of the rock. The geometry of the pore structure influences these properties and information concerning it, as well as the water content of the rock, can be inferred from multiple frequency dielectric measurements. Taken together, this information may allow a prediction of the flow properties of the rock.
Prop Transport in Hydraulic Fractures: A Critical Review of Particle Settling Velocity Equations
Authors: Clark Peter E. , Quadir Jamal A. 
Published: December 2007

ABSTRACT
The settling rate of particles in a fracturing fluid is a major factor in determining the distribution of propping agent in a hydraulic fracture. It is important to know the shape of the prop pack as well as the distribution of prop slurry in a fracture in order to optimize fracturing treatment designs. Terminal settling velocities of prop particles in hydraulic fracturing treatments are governed by fluid viscosity, fluid velocity, frac width, particle size, and particle density. There are a number of equations, based on both theoretical ground and empirical results, that can be used to predict the settling rate and thus the prop distribution in a fracture. Not all of these equations yield the same values for the terminal settling velocity of a particle under the same conditions. In this paper a number of the accepted methods will be reviewed. Predicted terminal settling velocities for a number of different conditions prevalent during a fracturing treatment will be presented.
When a particle falls through a liquid containing other particles, the terminal settling velocity of the particle is different than a single particle falling through the same liquid. This effect, termed hindered settling, can be handled in a number of different ways. Several of the equations used to treat hindered settling will be covered along with a critique of their applicability in prop transport calculations.
The Relationship of Permeability to Confining Pressure in Low Permeability Rock
Authors: Jennings James B. , Carroll Herbert B. , Raible Clarence J. 
Published: December 2007

ABSTRACT
Laboratory permeability measurements of low permeability (less than 1 md) reservoir rock is significantly affected by test confining pressure. Knowledge of the confining pressure is required to predict permeability at reservoir conditions. A model is proposed which relates electrical conductivity, permeability, and pore dimensions to confining pressure. The model assumes that rock pores are interconnected by thin cracks and microfractures which can be modeled by rectangular slits. For this model, core permeability is related to confining pressure by a third order polynomial, and electrical conductivity is related to confining pressure by a first order polynomial. Electrical conductivity and permeability versus confining pressure measurements were made on test cores having laboratory Klinkenberg permeabilities from 20 to 200 microdarcys. The experimental measurements were found to be consistent with the slit model theory.
NMR Determination of Porosity and Permeability of Western Tight Gas Sands
Authors: Cowgill Donald F. , Pitman Janet K. , Seevers D. O. 
Published: December 2007

ABSTRACT
Samples of fine-grained sandstone from the Colorado Interstate Gas Exploration (CIGE), Natural Buttes No. 21 core, Uinta Basin, Utah were studied using pulsed nuclear magnetic resonance (NMR) and standard mineralogical techniques. Brine-saturated rock porosities varied from 1 to 13 percent and were found deducible from the magnitude of the proton NMR. The complex pore geometry and presence of authigenic carbonate and clay minerals in these samples precluded the use of standard flow models for predicting brine permeabilities from T decays. A network model of the pore system is proposed and shown capable of accurately reproducing measured rock permeabilities, which varied from 10−4 to 1 millidarcy.