bluuebunny/crossref_metadata_2025_split huggingface dataset:
Gamma Ray Permeability Relationship in the Denver-Julesburg Basin
Authors: Smith Clarence E. 
Published: June 2009

Abstract
This paper is the result of an investigation made to determine an empirical relationship between Gamma Ray curves and core analysis permeability values for wells in the Denver-Julesburg Basin. It is proposed to show that an empirical relationship does exist and to present information and curves to substantiate the belief that we can derive permeabilities from Gamma Ray data. This type of information can be a valuable aid in application to Basin workovers and completion activities.

Introduction
The majority of Gamma Ray surveys are being taken for correlative information for use in conjunction with perforating of oil and gas pay intervals. All the service companies are now using the Scintillation type instrument. However, a number of currently producing wells have been surveyed with the Ionization type instrument; and in order to make this study comprehensive, both types of equipment are included in this investigation. This work is based on the theory that the permeability of the "D" and"J" sands of the Denver-Julesburg Basin is a function of the clay cementing material found in the pay zone pore space. The idea is not a new one as C.L. Rabe did the preliminary work, and he came to the conclusion that permeabilities could be related to Gamma Ray data. Using Rabe's recommended method for correcting Gamma Ray logs for drag, sensitivity changes, thin bed effects, and converting to a common scale was found to be entirely laborious. For practical reasons, it was decided to check and see if an empirical relationship could be established without going through all the corrections mentioned.
Development of Permeability Curves

Ionization Instrument
All the core analyses of wells that have been surveyed with the Ionization type instrument were compared for similarities in deflection changes and changes of permeabilities. In order to expedite this comparison, the core analyses were plotted on transparent paper using the same footage scale as the Gamma Ray log. It soon became apparent that plotting of these permeabilities would not correlate too well with the Gamma Ray curves. Therefore, it was decided to calculate the average weighted permeability of each foot of the core analysis.
Coupling Equation-of-State Compositional and Surfactant Models in a Fully Implicit Parallel Reservoir Simulator Using the Equivalent-Alkane-Carbon-Number Concept
Authors: Han C. , Delshad M. , Pope G. A. , Sepehrnoori K. 
Published: June 2009

Summary
Equation-of-state (EOS) compositional and surfactant models are coupled in a fully implicit parallel reservoir simulator using the equivalent alkane carbon number (EACN) of the oleic phase. The EACN of the oleic phase is computed using a mole-fraction-weighted carbon number for each component present in the oleic phase. Important microemulsion properties such as optimum salinity and optimum solubilization parameter as a function of the EACN of the oleic phase are implemented on the basis of known correlations. Type II(-) surfactant phase behavior is considered in this study. The simulator developed is validated using our implicit-pressure/explicit-concentration (IMPEC) chemical-flooding simulator. Case studies, including a large-scale simulation, emphasize that surfactant floods should be modeled carefully, taking the EACN of crude oil into consideration for more realistic and accurate oil-recovery predictions.
Numerical Modeling of Diffusion in Fractured Media for Gas-Injection and -Recycling Schemes
Authors: Hoteit Hussein , Firoozabadi Abbas 
Published: June 2009

SummaryDiffusion in fractured reservoirs, unlike in unfractured reservoirs, can affect significantly the efficiency of gas injection in oil reservoirs and recycling in gas/condensate reservoirs. The physical diffusion, similar to gravity, results in the change of the path of the injected gas species from the fractures to the matrix, giving rise to late breakthrough. In this work, we present, for the first time, a consistent model to incorporate physical diffusion of multicomponent mixtures for gas-injection schemes in fractured reservoirs. The multicomponent diffusion flux is related to multicomponent diffusion coefficients, which are dependent on temperature, pressure, and composition. These coefficients are calculated from a model based on irreversible thermodynamics. Current simulation models of fractured reservoirs that include diffusion are based on inconsistent models of gas-to-liquid diffusion at the fracture/matrix interface. We avoid this deficiency by assuming that the gas and liquid phases are in equilibrium at the interface. The concept of crossflow equilibrium (i.e., vertical equilibrium) is invoked in our model to avoid the use of transfer functions. In this work, we use the combined discontinuous Galerkin and mixed methods on 2D structured grids to calculate fluxes accurately and to have low numerical dispersion to study physical diffusion. Four examples are presented. In one of the examples, a field-scale study is performed to investigate gas injection in a fractured reservoir away from miscibility pressure and close to miscibility pressure. Results show a significant effect of diffusion on recovery performance away from miscibility pressure. In another example, recycling in a fractured gas/condensate reservoir is presented to demonstrate that diffusion has a significant effect on condensate recovery.
Transient Flow in Discretely Fractured Porous Media
Authors: Izadi Mehdi , Yildiz Turhan 
Published: June 2009

Summary
This paper presents a semianalytical model for transient flow into multiple vertical wells producing from a porous medium containing randomly distributed discrete fractures. Both vertical openhole wells and hydraulically fractured vertical wells are considered. The semianalytical model simulates pressure and pressure-derivative characteristics of wells and flow distribution along and through both the natural and the hydraulic fractures.
The study shows that single or multiple isolated natural fractures yield negative pseudoskin factors in vertical wells near isolated fractures. The negative pseudoskin factor is a function of fracture conductivity, density, length, distance from the wellbore, and azimuth.
Using the model, we demonstrate that the shape of the pressure derivative is related to fracture distribution. The results of this study indicate that the conventional double-porosity analysis to predict the storativity ratio of a naturally fractured system is not reliable. Also, the displacement between two semilog straight lines is not necessarily a good indicator of the storativity ratio.
Mechanisms, Parameters, and Modeling of Naphthenate-Soap-Induced Formation Damage
Authors: Sarac S. , Civan F. 
Published: June 2009

Summary
Naphthenate-soap deposition and the related formation damage in petroleum reservoirs are investigated by means of laboratory-scale experimental and theoretical studies. Experiments were carried out in three directions to understand and quantify the naphthenate-soap-deposition problem. Static bottle tests were conducted to determine the precipitation rate for various pH and temperature conditions. Microscopy investigations were carried out to verify the growth of naphthenate-soap particles under different pH conditions. Core-flow tests were conducted to generate naphthenate-soap particles and to determine the permeability impairment caused by subsequent deposition of these particles in porous media under flowing conditions and different pH values. A power-law expression was proposed and verified for the precipitation rate of the naphthenate-soap particles. The parameters of the rate equation were correlated with respect to pH and temperature. This also allowed the determination of the critical pH value for the onset of naphthenate-soap precipitation. The results of the particle-size experiments were described by a particle-growth equation, and the parameters of the equation were correlated with respect to pH. The core-flow experiments proved the occurrence of formation damage caused by naphthenate-soap precipitation and subsequent deposition. The permeability impairment in core-flow experiments was described by a new differential model. The applications presented in this study provide insights for understanding the mechanism and magnitude of naphthenate-soap-induced formation damage and help in taking proper measures to avoid the formation damage caused by naphthenate-soap deposition.
Lease Automation: The Present and the Future
Authors: Morgen Ralph A. , Young Edwin C. 
Published: June 2009

Production Automation Practical
Workable and economical equipment is available today to give automation from the wellhead to the pipeline. This automation can be most readily divided into three groups of equipment: Group 1, "Flowing and Production Controls";Group 2, "Well Testing"; and Group 5, "Custody Transfer". Let us examine each of these groups separately to determine the requirements of each.

Group 1, Flowing and Production Controls
These controls are required to regulate flow from the wellhead to the flowline, pressure control in the flow line and production equipment, level control in the production equipment, and temperature control where required. Access from wellhead to pipeline is provided through valving on flowing wells and through the pumping unit for wells on pump. The automation controls require dare used to shut-in the well when required by a preset program or in response to an alarm condition. The normal pressure, level, and temperature controls used on the production equipment are included in the alarm system.
An automated lease usually consists of several wells being produced into a central production facility. For ease of handling it is usually expedient to locate several flow diverter valves connected together into a manifold for the purpose of routing the fluids from the wellhead to either production or test facilities. Where flowing wells are manifolded together, it is often practical to use three-way, three-position valves for the purpose of shutting in the well.
It is an exception for this three-position valve to be the only shutoff between the wellhead and the production equipment. It is more common to close both of the outlets of the three-position valve to cause pressure to build up in the flow line. A two-way valve, installed at the wellhead and controlled by a hi-lo pressure pilot, senses this rising pressure and shuts in the well. For leases with relatively short-distance flow lines, a low pressure signal to the hi-lo pressure pilot may be used to indicate a ruptured line, and will cause the pilot to shut-in the well. Thus, the pilot acts as a high and low safety device as well as the means of shutting in the well in accordance with programming or in response to an alarm shut-in condition.
Wire Line Formation Testing in Open and Cased Holes in Southern Louisiana
Authors: Fischer J.S. , Havard E.H. , Van Ness A.E. 
Published: June 2009

Abstract
The Formation Tester is a tool which is run in either open or cased holes on a conventional logging cable. Tests may be made rapidly and safely at various depths in the hole. The Formation Tester provides: a sample of the formation fluids, GORs, a means to determine accurate gas-oil, or oil-water contacts, bottom hole pressure data, an index to the permeability of the small zone adjacent to the tool.
There are many formation testing problems peculiar to soft formations. Development of solutions has been very successful. The problems encountered and their solutions were:The percentage of successful tests was less than expected because unconsolidated sands would not support the packer. This problem was almost completely solved by the introduction of the shaped charge and snorkel testers.The number of fishing jobs needed to be reduced. This problem was overcome by keeping the cable in constant motion so that hydrostatic pressure could not seal the cable to the wall of the hole.Interpretation was confusing. It was found after many tests that the amount of oil or gas recovered was the factor which determined what the ultimate production would be. The water produced should not be used as an indicator of final production.
The Wire Line Formation Tester has recently been used in cased holes with very good success. The operation and application are similar to those in open holes with the following additional applications: old wells may be tested, cement jobs can be evaluated for channeling, directional holes may be tested without wire line hazards.

Introduction
The Wire Line Formation Tester has, in the past year, become widely used and is now becoming a standard tool for formation evaluation in Southern Louisiana. During the first two years of testing the soft formations of these coastal regions, results were not as satisfactory as had been anticipated. Many problems were present. Many solutions were attempted. The purpose of this paper is to describe the equipment and techniques which have contributed to the recent success of the tester. In addition, the newly developed method of testing in cased holes will be discussed.
Study of Enhanced-Oil-Recovery Mechanism of Alkali/Surfactant/Polymer Flooding in Porous Media From Experiments
Authors: Shen Pingping , Wang Jialu , Yuan Shiyi , Zhong Taixian , Jia Xu 
Published: June 2009

Summary
The fluid-flow mechanism of enhanced oil recovery (EOR) in porous media by alkali/surfactant/polymer (ASP) flooding is investigated by measuring the production performance, pressure, and saturation distributions through the installed differential-pressure transducers and saturation-measurement probes in a physical model of a vertical heterogeneous reservoir. The fluid-flow variation in the reservoir is one of the main mechanisms of EOR of ASP flooding, and the nonlinear coupling and interaction between pressure and saturation fields results in the fluid-flow variation in the reservoir. In the vertical heterogeneous reservoir, the ASP agents flow initially in the high-permeability layer. Later, the flow direction changes toward the low- and middle-permeability layers because the resistance in the high-permeability layer increases on physical and chemical reactions such as adsorption, retention, and emulsion. ASP flooding displaces not only the residual oil in the high-permeability layer but also the remaining oil in the low- and middle-permeability layers by increasing both swept volume and displacement efficiency.
Analytical Determination of Optimum Bit Weight and Rotary Speed Combinations
Authors: Graham J.W. , Muench N.L. 
Published: June 2009

Abstract
This paper presents an analytical method for the selection of optimum combinations of rotary speed and bit weight to minimize total drilling cost. A mathematical analysis of the cost to drill any depth interval is the basis of the method. In the analysis, it is assumed that the total drilling cost can be expressed as the sum of rig cost for making round trips, rig cost for drilling, and bit cost. It is further assumed that bit life is limited by bearing failure, that bit weight is not limited by considerations such as hole deviation, and that drilling hydraulics are adequate. Based on these assumptions, the following important question is proposed: Do optimum combinations of bit weight and rotary speed exist which will minimize the cost to drill specified depth intervals? This question is understood more specifically through a consideration of the following facts. When either bit weight or rotary speed is increased, the rig cost for drilling becomes less because penetration rate is increased. However, when greater bit weight and/or faster rotary speed is used, both rig cost for making round trips and bit cost become greater because bit life is decreased. Whether or not a change in bit weight (or rotary speed) will increase or decrease drilling cost is determined by a mathematical analysis.
To perform the analysis, the results of past field experience are used to derive empirical mathematical expressions for bit life expectancy and for drilling rate as a function of depth, rotary speed, and bit weight.
The Future Course of United States Exploration
Authors: Gardner Frank J. 
Published: June 2009

Abstract
Oil exploration in future will depend more and more upon proper thought and perspective on the part of those engaged in it. Success will demand flexibility and imagination in order to picture the possible occurrences of oil which are not readily evident at the surface.
There will be an increasing emphasis on world-wide exploration, and Americans will be the leaders in this world-wide search. We need not fear the apparent flood of oil which might result, for in the long run the world is going to need every drop of oil energy that it can muster. The supply of oil is a finite thing, and within a hundred years or so a new kind of energy must takeover the world.
There are numerous unexplored habitats of oil in the United States. The most important ones lie in the Rocky Mountain states, on the continental shelves, and in Alaska. But other less important ones are scattered from coast to coast.
In addition, a great deal of oil is yet to be discovered in unexploited habitats of oil. These include the deeper measures in older provinces and the ample flanks of sparsely-explored basins of the west and Midwest.
For the past few years, the oil finding profession has been undergoing some sweeping changes. These fall into several fields, but all are involved with THOUGHT and PERSPECTIVE. Webster defines perspective as "the capacity to view things in their relation or relative importance; i.e., some folks can'tsee the wood for the trees, while others have perspective." In terms of logic, all perspective is thought, but not all thought is perspective.
It is this last phrase with which we're concerned here. A successful oil finder now and in the future is the man who can form images in his mind and relate them one to the other in proper perspective. More important, his mind is flexible enough to narrow this perspective to focus on the problem immediately at hand, or broaden it to encompass the world.
Research on Methods for Improving Oil Recovery in Pennsylvania Oil Fields
Authors: Slobod R.L. 
Published: June 2009

Introduction
It is now common knowledge in the industry that only about one third of the oil in known reservoirs will be recovered by present methods of production. Since 240 billion barrels of oil have been discovered and only 90 billion barrels are expected to be produced, the unrecovered oil in fields already discovered amounts to approximately 150 billion barrels. This tremendous quantity of oil is of great economic value and is the prize for those who devise new or improved methods for increasing recovery.
One approach being used by many to obtain some of these reserves is the use of heat and "in-situ" combustion as a recovery scheme. Such methods are particularly adaptable to viscous crudes which apparently cannot be recovered by any other known scheme.
A second and different approach is based on the fact that oil can be displaced completely by fluids miscible with it. Consequently, we are presently seeing great activity ill the-industry in the development and testing of a variety of miscible displacement schemes for increasing recovery. The most common of these which are now being field tested include high pressure gas displacement, condensing gas drive, and the LEG slug process. All of these methods require the use of pressure of the order of 1500 psi or higher. Unfortunately, most of the old Pennsylvania fields are shallow. The material in this paper describes some of the efforts of our laboratory to develop a type of miscible displacement which works at low pressures and so would be applicable to Pennsylvania oil fields. In particular, we have been working on the development of a relatively new modification of the miscible flood called the"Alcohol Slug Process." The work reported here describes this process, and discusses supporting studies which were performed to test or prove the validity of the laboratory work.
Present Status of Nuclear Magnetism Logging
Authors: Coolidge J.E. , Gamson B.W. 
Published: June 2009

Abstract
The Nuclear Magnetism Log (NML), which responds only to formation fluids, is described. Basic principles on which this new development rests are reviewed. Field examples are given for a broad spectrum of operating conditions. These include large variations in mud composition, different geological provinces, various reservoir rock conditions, a wide range of formations fluid contents and composition, and well depth, temperature and pressure. Two distinct NML measurements are made. The Free Fluid Index (FFI) is a formation permeability and productivity, and is an excellent correlation index. Thermal relaxation data (T1) distinguish oil or gas and water zones with good reliability and provide information about reservoir permeability.

Introduction
The purpose of well logging is to obtain quantitative information about the presence and amount of reservoir fluids and the characterization and percentage of their chemical species namely, hydrocarbon or water. Other useful information desired is formation fluid for production. In addition, it is useful to have a logging technique which is a good correlation between well sand is universal in application irrespective of hole geometry, mud composition, reservoir rock composition, and physical properties, etc.
Interpretation of existing commercial logging techniques is predicated upon empirical correlations derived from the measurement of gross reservoir properties. They are in the main properties such as resistivity, transmission of sound, natural radioactivity, induced radio-activity, and spontaneous potential which are not simple functions of the diverse reservoir rocks and fluid compositions encountered in oil exploration. The use of other than a primary property of the reservoir fluid frequently gives rise to ambiguous interpretation of well logging data. For a long time a direct means has been sought of measuring some physical or chemical property of solely the reservoir fluids and not the rock matrix to yield a relatively unambiguous result.
Measurement of the nuclear magnetic properties of protons offers a unique means of meeting the objectives of well logging. Under operating conditions in the borehole, nuclear magnetism logging is responsive only to hydrogenous fluids in the reservoir. The magnitude of the signal is quantitatively related to the geometrical configurations of the tool and borehole and the thermodynamic and nuclear magnetic properties of the formation fluids.