bluuebunny/crossref_metadata_2025_split huggingface dataset:
Field Experiences with an Environmentally Acceptable Rotary-Shouldered Thread Compound
Authors: Stringfellow W. D. , Jacobs N. L. 
Published: December 2007

Abstract
Environmental regulations are prompting the oil and gas industry to consider replacement of thread compound formulations which have served for more than three decades. Replacement is necessary because these traditional compounds contain significant percentages (up to about 65%) of heavy metal powders. Use of copper, lead and zinc, as well as persistent synthetic materials, such as PTFE, has been restricted by environmentally conscious governments. Replacement presents several problems because of the nature and severity of the application.
This paper summarizes field experiences using a new technology rotary shouldered thread compound. This work includes field tests and drilling experiences in several geographic areas. In addition, it describes practical challenges and economic considerations with an environmentally acceptable compound.
Because new technology is needed soon, this paper provides a brief overview of the application, general performance requirements, and basis for changing to environmentally acceptable compounds.
The IADC Roller Bit Classification System
Authors: McGehee D. Y. , Dahlem J. S. , Gieck J. C. , Kost Bill , Lafuze Dave , Reinsvold C. H. , Steinke S. C. 
Published: December 2007

ABSTRACT
The LADC (International Association of Drilling Contractors) roller bit classification system provides a convenient method for categorizing rock bits according to their design features and intended applications. The system has been used worldwide since 1972. The 1992 version includes improvements which reflect the latest design trends in roller cone bits.
This paper explains the IADC roller bit classification code. Current classification charts are shown for major bit manufacturers. The relationship between the LADC code, bit design factors, and operating guidelines is discussed. Examples depict the major design features included in the code.
Since this version contains only minor changes from the 1987 Roller Bit Classification System,1 these changes will be listed at the beginning of the paper. Those experienced with the code need only read the changes. Subsequent paragraphs present a complete discussion of the classification system for the benefit of the readers who may not be familiar with the system or who wish more detail. IADC bit topics also updated in 1992 include Fixed Cutter Classification2 and Dull Bit Grading.3,4
New Horizontal Drilling Techniques Using Coiled Tubing
Authors: Wesson H. R. 
Published: December 2007

ABSTRACT
This paper describes the status of an ongoing project to both prove the feasibility of and provide a testbed for the development of processes and tools for drilling with coiled tubing. To date a total of three horizontal wells have been drilled in the Austin Chalk formation in Texas. These wells consisted of two 4 1/2" (114 mm) reentries in the Pearsall Field and one 5 1/2" (140 mm) reentry in the Austin Chalk near Bryan, Texas. To our knowledge these are the first horizontal wells to be drilled using coiled tubing.
These wells have been drilled using 2" (50.8 mm) coiled tubing with a 0.156" (3.96 mm) nominal wall, downhole mud motors, wireline steering tools and downhole mechanical orienting tools. The coiled tubing had a 5/16" (7.9 mm) single conductor wire installed inside it to allow the use of conventional wireline steering tools. The tools and techniques developed during this project and the advantages, limitations and future potential for this type of drilling operation are the subject of this paper.
Geophysical Methods for Reservoir Characterization
Authors: Zimmerman L. J. , Chen S. T. 
Published: December 2007

ABSTRACT
Petroleum resources are finite and becoming ever more elusive. As known reserves are depleted, efficient management of existing reservoirs is crucial. One valuable tool for reservoir development is computer simulation. Unfortunately, although the technology is available to construct geologically complex computer models of reservoirs, the level of detail which can be included in such models is far beyond the ability of traditional methods for measuring reservoir properties to accurately constrain those models. For example, geostatistical techniques permit a modeler to describe a geologic representation of a generic reservoir which is realistic and empirically matches historical measurements related to reservoir performance. However, the resulting model will not be a true representation of the specific reservoir and consequently predictions based on the model may be suspect. Seismic imaging methods are emerging as promising new measurement tools which can be used to bridge the information gap between wells and help constrain stochastic models. 1
Recent breakthroughs in hardware and software have improved the resolution of seismic methods to the point where they can now address production-scale problems. Parameters and attributes extracted from seismic data can be empirically and analytically related to rock properties of interest for reservoir development. This offers the tremendous potential for improving profitability through efficient development of reservoirs. This paper will illustrate the application of seismic imaging to, characterize reservoir properties. Examples from two geologic settings will be used to compare the resolution of four seismic imaging methods; Surface Seismic Surveying, Reversed Vertical Seismic Profiling (RVSP), Cross well Reflection Imaging, and Crosswell Tomography.
Microbes: The Practical and Environmental Safe Solution to Production Problems, Enhanced Production, and Enhanced Oil Recovery
Authors: Brown F. G. 
Published: December 2007

ABSTRACT
This paper presents the theory and field application of microbial treating oil well systems and reservoirs to control paraffin wax deposition, increase producing rates and enhance oil recoveries. The technology applies to paraffin base crude oils produced from solution gas drive reservoirs. The application of this microbial enhancement technology can increase oil recoveries in all stages of reservoir depletion.
Techniques for Accelerating Production Response in Steam-Foam Recovery
Authors: Mohammadi S. S. 
Published: December 2007

ABSTRACTIncremental oil production response to steam-foam application can be accelerated by improved surfactant formulations and modification of techniques for foam emplacement. By considering the effect of gravity on surfactant and steam flow, a number of injection strategies for accelerating production response have been developed using a steam-foam simulator. The prototype model used, is an idealization of a section of Midway Sunset Field. Comparisons are made between various steam and foam injection strategies at different formation intervals. The results indicate that by injecting foam high in the structure while injecting steam near the bottom, production response can be accelerated over bottom injection alone. Maximum recovery can be achieved by gradually lowering the foam injection interval while injecting a portion of the foam near the bottom of the structure. Mechanically, these techniques can be implemented by multiple completion methods, simultaneous injection through tubing and annulus, or use of two adjacent wells for steam and steam-foam injection. Although demonstrated results are reservoir specific, the concept can be extended to other types of structures since the underlying principal deals with optimum placement of the surfactant for correcting gravity override.
Case History of Pressure Maintenance by Crestal Gas Injection in the 26R Gravity Drainage Reservoir
Authors: Wei M. H. , Yu J. P. , Moore D. M. , Ezekwe Nnaemeka , Querin M. E. , Williams L. L. 
Published: December 2007

ABSTRACT
This paper is a field case history on the performance of the 26R Reservoir. This is a gravity drainage reservoir under pressure maintenance by crestal gas injection. The 26R Reservoir is a highly layered Stevens turbidite sandstone. The reservoir is located in the Naval Petroleum Reserve No.1 (NPR-1) in Elk Hills, Kern County, California (Figure 1). The 26R Reservoir is contained within the steeply dipping southwestern limb of the 3 1S Anticline. The reservoir had an initial oil column of 1,800 feet. Original oil-in-place (OOIP) was estimated at 424 million barrels.1
Pressure maintenance by crestal gas injection was initiated immediately after production began in October 1976. The total volume of gas injected is about 586 BCF. This exceeds one reservoir pore volume. Reservoir pressure has declined from 3,155 psia to 2,461 psia at 6,000 feet subsea. This pressure decline is believed to be due to migration of injected gas into the overlaying shale reservoirs. Under the gas injection pressure maintenance strategy, reserves are estimated to be approximately 212 million barrels.
Reservoir studies have concluded that the aquifer at the base of the reservoir has been relatively inactive. Well recompletions, deepenings, and horizontal wells are used to improve oil recovery.
An aggressive program of controlling gas production began in the mid 1980's by the installation of multiple packers and sleeves. As the gas-oil contact (GOC) has dropped, sand intervals have subsequently been isolated behind packers. A cased hole logging program was recently undertaken to identify possible remaining reserves in the gas cap.
Thermal Simulation of Elk Hills Light-Oil Steamflood Pilot
Authors: Burzlaff A. A. , Harris B. R. 
Published: December 2007

ABSTRACT
A light oil steamflood pilot project was conducted from 1987 to 1991 in the Shallow Oil Zone of the Elk Hills field. A thermal simulator, employing a distillable component and a non-distillable component, was used to construct a steamflood model and duplicate over three years of pilot performance. In addition, a conventional black oil model was used to duplicate pre-pilot primary production performance and quantify the distribution of oil, water and gas saturations prior to the start of steam injection. Uneven thermal energy distribution and limited steam zone temperatures minimized the effectiveness of the steam distillation recovery mechanism.
Imbibition Assisted Two-Phase Flow in Natural Fractures
Authors: Babadagli Tayfun , Ershaghi Iraj 
Published: December 2007

ABSTRACT
For modeling naturally fractured reservoirs (NFR) under active water drive, the multi-phase flow in the fractures and the interporosity flow effects need to be formulated accurately to represent the physics of the countercurrent imbibition.
This paper presents experimental results on two-phase (oil and water) flow through natural fractures under many different configurations. Flow experiments were enhanced with the saturation measurement technique using the CT scan. Important variables in our experiments were the nature of the matrix rock and its wettability characteristics and fracture configuration. A wide range of matrix wettabilities were investigated. Flow rate in the fractures, which plays a significant role in effectiveness of the countercurrent imbibition, was carefully monitored.
Relative permeability measurements for the bulk system were conducted under unsteady state flow conditions. Unlike homogeneous systems with a single set of relative permeability plots, for the fractured systems under study, a series of plots are generated. Composite system relative permeability response, which are referred to as Effective Fracture Relative Permeability (EFRP) curves, are formulated. This formulation is a potential tool for reducing the dual-porosity model to a fracture network model, where the matrix is a sub-system of the fracture network, and the matrix-fracture interaction is represented by the EFRP.
Inflow Performance of Slanted and Horizontal Wells in Solution-Gas Drive Reservoirs
Authors: Kabir C. S. 
Published: December 2007

ABSTRACT
Simple analytic tools are presented to predict a horizontal or slanted well's inflow performance relationship (IPR) producing from a solution-gas drive reservoir. Although a great body of work has been reported for a vertical well's performance during two-phase flow in the reservoir, only a few papers describe the same for a slanted/horizontal well.
Two recent studies developed empirical correlations for horizontal wells along the lines of Vogel, who had correlated flowing bottomhole pressure with flow rate for vertical well-bores by using numerical simulations. This work shows the difficulty of using these new correlations for evaluating the absolute open flow potential (AOFP), thereby limiting their applications in a predictive mode when field data are unavailable.
We also show that once the AOFP or the maximum oil flow rate is properly evaluated, both Vogel and Fetkovich correlations, originally intended for vertical wells, can be used to describe a well's IPR regardless of its orientation. Likewise, methods available for future prediction of a vertical well's IPR are equally applicable for wells having a different orientation. The AOFP can be computed by using any of the productivity index expressions developed for horizontal wells for various outer-boundary conditions. For slanted wells, the Cinco et al. correlation is used to calculate an effective wellbore radius and hence the well's productivity index.
Synthetic examples are used to show the application of the proposed methodology for computing a slanted well's IPR. On the other hand, a field example illustrates the method's applicability in a horizontal well.
Characterization and Removal of Amorphous Aluminosilicate Scales
Authors: Braun Gerald , Boles J. L. 
Published: December 2007

ABSTRACT
Characterization of amorphous aluminosilicates is best accomplished using an integrated approach involving polarized light microscopy, X-ray diffraction, and SEM-EDS analyses. The amorphous scales discussed in this study are from the near wellbore area and consist primarily of SiO2 and Al2O3 with minor Na2O and H2O. Their refractive index ranges from 1.49 to 1.51, and at least one broad X-ray diffraction "hump", ranging from d = 3.1 Å to 3.5 Å is always present. Field results and laboratory studies indicate that effective removal of these deposits generally requires the use of a combination acid treatment. The use of an organic acid preflush (10% acetic) followed by hydrochloric-hydrofluoric (12%-3%) acid has been particularly successful. In addition, metal chelating agents (e.g., nitrilotriacetic and citric acids) should be incorporated in all acid treating systems to prevent aluminum-rich amorphous phases from reprecipitating.
Deep Heavy-Oil Recovery by Steam Injection Using Twin Horizontal Drainholes
Authors: Cooper G. A. , Gondouin Michael , Zeyrek M. S. 
Published: December 2007

ABSTRACT
We propose a novel method for improving the efficiency of recovery of heavy oil. Two horizontal drainholes are made at the bottom of a vertical well so that one may be steamed while the other is in production. Downgoing steam and rising produced fluids are carried in the same vertical casing so that heat from the produced fluids reduces heat losses from the steam. This arrangement requires a downhole valve that will switch steam and produced fluids between the boreholes. We discuss the design of a suitable well and of the valves, and report results of tests to select suitable materials to function in the high temperature downhole environment.
Options Theory: A New Way Forward for Exploration and Engineering Economics?
Authors: Markland J. T. 
Published: December 2007

Abstract
Techniques used in conventional project appraisal are mathematically very simple in comparison to those used in reservoir modelling, and in the geosciences. Clearly it would be possible to value assets in mathematically more sophisticated ways if it were meaningful and worthwhile so to do. The DCF approach in common use has recognised limitations; the inability to select a meaningful discount rate being particularly significant. Financial Theory has advanced enormously over the last few years, along with computational techniques, and methods are beginning to appear which may change the way we do project evaluations in practice.
The starting point for all of this was a paper by Black and Scholes, which asserts that almost all corporate liabilities can be viewed as options of varying degrees of complexity. Although the financial presentation may be unfamiliar to engineers and geoscientists, some of the concepts used will not be. This paper outlines, in plain English, the basis of option pricing theory for assessing the market value of a project. It also attempts to assess the future role of this type of approach in practical Petroleum Exploration and Engineering economics. Reference is made to relevant published Natural Resource literature.
The Anatomy and importance of Project Finance for Oil and Gas Developments
Authors: Whyatt A. S. 
Published: December 2007

Abstract
Project financing can be of great benefit to oil and gas projects because by separately identifying and securing assets and cashflows it can provide large sums not otherwise accessible to whole projects or to individual companies. Project financing is of interest to members of the SPE because it routinely requires the expertise of petroleum engineers and other professionals to vouch for the viability of petroleum projects and the recoverability of reserves. Its essential attraction is that risk analysis and the application of precise professional criteria enable large projects and amounts to be financed, which otherwise might not occur. This is particularly the case when there are a number of participants in a large project, none of which is on its own able to support the finance. The growth in the average size of projects means that an increasing number of projects must be financed in this way or not be able to go forward.
An Integrated Approach to Prediction of Hydrocarbon in Place and Recoverable Reserve With Uncertainty Measures
Authors: Abrahamsen Petter , Egeland Thore , Lia Oddvar , Omre Henning 
Published: December 2007

Abstract
A method for calculating the probability distribution for oil in place and recoverable reserve is presented. A stochastic reservoir model describing spatial variability is specified and conditioned on available observations. A large set of possible reservoirs are generated from the specified model by stochastic simulation. This set of simulated reservoirs displays the uncertainty and variability in the stochastic model and they can be further processed to
– obtain probability distributions for oil in place and recoverable reserve, – compare contributions to the uncertainty, – constructing maps showing the uncertainty, – evaluate reduction in uncertainty when drilling new wells, – study the uncertainty in the lateral extension of the reservoir.
The first part of the paper outlines the stochastic models for the geometry and the petrophysics. The last part shows several examples of results from case-studies. Emphasis is made on graphical presentations of maps and probability distributions.
Automatic Optimization of Well Locations Using a Front Tracking Reservoir Simulator
Authors: Søreide Ingolf , Flach T. A. , Rian D. T. 
Published: December 2007

Abstract
Waterflood projects on land often well spacing for development, e.g. 5-spot pattern with 40-acre spacing. Deep water offshore waterflood projects, in contrast, are limited to far fewer wells, and hence, well density and location are critical design parameters.
Numerical simulators are often used to optimize these parameters, frequently at considerable expense, using manual trial-and-error techniques and three-dimensional (3D) finite difference simulators.
This study applies an automated technique for the optimization of well locations in a North Sea reservoir developed by waterflooding. An optimization routine was combined with a two-dimensional (2D) areal front tracking reservoir simulator. The simulator is characterized by being very CPU efficient, independent of grid orientation, and free of numerical dispersion.
With the objective of maximizing pretax net present value of oil production, the optimizer was used to find the optimal well locations for two injectors and two to three producers. Optimization runs were performed for a seven-well development case and an alternative nine-well development case. Both cases were examined using two different flood directions.
Results from several optimization runs are presented, including the optimal well locations found. In addition, production data are compared for different optimization runs.
The procedure proved to be both CPU and man-time efficient, and is recommended as a screening method prior to using large, more detailed 3D numerical models.
Optimization Techniques Application in Oil Recovery Problems
Authors: Virnovsky G. A. 
Published: December 2007

Abstract
The paper surveys several applications of the optimization algorithms in different problems of oil reservoir development, well testing and gas resource distribution for gas lift wells. For all these cases the optimization technique proved to be beneficial. The results of calculations show, that the optimal solution may give a substantial gain in oil production in the first and third cases. In the second case the optimization formulation of the problem is the only opportunity to solve it.
A New Approach for Modeling Fluid Inertia Effects on Sucker-Rod Pump Performance and Design
Authors: Khodabandeh Ardeshir , Miska Stefan 
Published: December 2007

ABSTRACT
The elastic behavior of the sucker-rod string, in most models, is simulated by a second-order wave equation with a viscous damping factor, which does not consider the inertia effects of the fluid surrounding the rod string. To consider these effects, another system of first-order wave equations must be solved simultaneously with the rod string equation. Solution of the system of partial differential equation becomes even more complicated if the sucker-rod string properties are not uniform. Because tapered and combination rods are often used in the string, a new approach has been developed. This approach can simulate any combination of rods and fluid inertia effects in a relatively simple and effective manner. It applies the Bergeron method, which can be used for pressure and stress propagation in fluids and solids respectively, by using a system of linear algebraic equations instead of the wave equation(s). A simple example problem is solved before applying the approach to a sucker-rod pumping system. The numerical results are compared to the actual measured surface dynamometer cards. Analysis of the numerical results shows that the fluid inertia effects are important for accurate modeling and design of the sucker-rod pumping system.
Light Oil Recovery from Cyclic CO2 Injection: Influence of Drive Gas, CO2 Injection Rate, and Reservoir Dip
Authors: Karim Fatma , Berzins T. V. , Schenewerk P. A. , Bassiouni Z. A. , Wolcott J. M. 
Published: December 2007

ABSTRACT
Laboratory corefloods were performed to investigate the effects of CO2 injection rate, reservoir dip, and the use of a drive gas on the cyclic CO2 stimulation process. Experiments were conducted in 6 foot long Berea sandstone cores using Timbalier Bay, a light oil, under immiscible conditions (500 psig and 78 °F).
Process performance was maximized at moderate injection rates. Oil recovery efficiencies and gas utilization factors were poorer at very high or low injection rates. The inclination of the core and the site of injection substantially influenced oil recovery efficiencies and gas utilization factors. Process performance was favored when CO2 was injected into the lower end of a core tilted at a 45 or 90 degree angle. The use of a horizontal core or injection into the top of a tilted core yielded a poorer response.
The benefits of a nitrogen drive (or chase) gas were evaluated by comparing the results of injecting CO2 followed by nitrogen with injection of CO2 or nitrogen alone. First cycle injection of a certain mass of CO2 followed by nitrogen yielded over twice as much oil as injection of that mass of CO2 alone. In the second injection cycle, the drive gas experiment recovered over three times as much oil as recovered by CO2 alone.