bluuebunny/crossref_metadata_2025_split huggingface dataset:
Wettability Of Reservoir Minerals By Flotation And Correlation With Surfactant Adsorption
Authors: Celik Mehmet S. , Somasundaran P. 
Published: December 2007

ABSTRACT
Minerals can undergo significant alterations in wettability upon adsorption of surfactants on them. A method that appears promising for measuring wettability is flotation using air or oil extraction. Unlike contact angle, it does not require such drastic treatments as polishing. Good correlation was obtained in the present study between wettability as determined by flotation and adsorption density. Both air flotation and adsorption exhibit maxima in the same concentration range. Zeta potential of particles measured under the same conditions, however, shows a continuous increase in its negative value with sulfonate concentration. Correlation of these data suggests that sulfonate monomers adsorb in increasing amounts below as well as above the critical micelle concentration but with a reverse orientation. There is however a decrease in measured surface excess, possibly due to such factors as precipitate redissolution and micellar exclusion.
A combined approach using adsorption, wettability, zeta potential and surface tension shows promise as a valuable method for the study of mechanisms of interaction of surface active agents with minerals.
Operating Practices in Carthage Field
Authors: Rockwell Don E. , Coe Raymond H. 
Published: December 2007

Abstract
Through the cooperative participation of operators in the Carthage Field, a summarization of field completion practices has been prepared. This paper presents the results of an SPE questionnaire to determine operator preferences in tubular sizes, cementing practices, electric log interpretation, perforating techniques, fracture design and implementation, pre-frac and post-frac surveys, well clean-up procedures, and operational methods in the Carthage (Cotton Valley) Field. This summarization makes no attempt to identify particular operators with specific techniques, but endeavors to present an overview of the various field procedures being employed.
Fundamentals of Fracturing
Authors: Daniel Gene , White Jerry 
Published: December 2007

Abstract
The basic theory of massive hydraulic fracturing as it relates to rock mechanics and rock properties will be reviewed with particular emphasis on the Cotton Valley Formation. The assumptions and basic concepts in frac geometry and orientation will be discussed. The parameters required for design will be identified and their effect delineated. Although this paper will be geared for a general understanding of fracturing, recent findings in rock mechanics and key areas requiring further definition will be presented.
The Effect of Microscopic Core Heterogeneity on Miscible Flood Residual Oil Saturation
Authors: Spence Andrew P. , Watkins Robert W. 
Published: December 2007

Abstract
Much effort has been devoted to understanding the mechanisms responsible for the variation of CO2 flood residual oil saturations found both in the laboratory and in the field-Some of the many possible explanations are the detailed nature of CO2/oil phase behavior, trapping of oil by mobile water, viscous fingering, and bypassing of oil due to the micro-pore structure of a given porous medium. The purpose of this study was to investigate the influence of rock characteristics alone on misciblє displacement behavior through a combination of displacement testing and modeling. Modeling was used to characterize the displacements and to extrapolate the observed phenomena to untestable conditions. The displacement tests were used to calibrate the model and to test the model's predictive capabilities.
A number of stabilized CO2 displacements and xylene displacing iso-octane tests were conducted in both outcrop sandstones and San Andres reservoir carbonate core samples. By flooding with xylene displacing iso-octane, phase behavior complications and viscous fingering were avoided. Such an idealized displacement represented the "best case" laboratory miscible displacement. Effluent concentration profiles for the xylene displacing iso-octane floods were matched to the capacitance-dispersion model of Coats and Smith1 to estimate the magnitude of axial dispersion and so-called "dead-end" pore volume or capacitance.
The latter quantity was found to be essentially zero in outcrop sandstones but quite variable in the highly heterogeneous San Andres carbonates, attaining values as high as 50%. Axial dispersion followed similar trends. The carbonates displayed more variable and larger axial dispersion than the sandstones.
First contact and CO2 miscible flooding residual oil saturations were compared in the same core samples. Both measures of residual oil saturation were in agreement and depended on the particular sample. These data suggest microscopic heterogeneity is a primary determinant of residual oil saturation to miscible flooding when viscous fingering is controlled. Microscopic heterogeneity resulting from a non-uniform pore structure was characterized by the level of dispersion and capacitance in the rock sample. In addition, both laboratory data and model prediction showed that the effect of dispersion and capacitance on residual oil saturation decreased as the displacement was extrapolated to reservoir rates and system lengths of a few feet. This implies that microscopic heterogeneity is more important in laboratory systems than in field displacements.
High-Strength Nickel-Alloy Tubulars for Deep, Sour Gas Well Application
Authors: Vaughn Glen A. , Greer James B. 
Published: December 2007

ABSTRACT
There is considerable interest in producing deep, high-pressure reservoirs that contain substantial amounts of sour gas. Because of the great depths and pressures involved, it is necessary to use high-strength tubular materials if safety features such as a downhole packer are to be incorporated into the completion design. It is known that sour production from these wells is severe from the standpoint of corrosion and sulfide-stress cracking of high-strength steels. Recent work has also identified two potential problems with high-strength, nickel-alloy tubulars. These problems are related to environmental embrittlement: (1) hydrogen-embrittlement cracking, which is a concern in the cooler, upper portion of the well during extended periods of shut-in and (2) stress-corrosion cracking, which is a concern at elevated temperatures downhole. This paper describes these problems and discusses the major environmental and metallurgical variables in terms of the conditions present in a deep, sour-gas-well completion. In addition, the progression from laboratory testing to full-scale high-alloy tubular manufacture, including specifications, is reviewed.
A New Stimulation Technique: High Strength Crosslinked Acid
Authors: Pabley Avtar S. , Holcomb David L. 
Published: December 2007

ABSTRACT
A new revolutionary crosslinked high strength hydrochloric acid system (patent pending) has been developed which provides much better retardation of acid activity on the formation than the existing retarded acid systems1,2. The retardation effect has been established by laboratory testing up to temperatures of 350°F (176.7°C).
Now, the acid gel having hydrochloric acid concentrations of 14% to 28% and a pH less than one can be crosslinked for effective retardation. This new crosslinked acid has high viscosity with shear stability providing perfect support for proppants. Additionally, this new system has excellent clay stabilization and emulsion prevention properties.
Field treatments using this new crosslinked acid system for the Greater Aneth, San Juan County, Utah, will be discussed.
Preliminary Estimation of The Reservoir Capacity and the Longevity of the Baca Geothermal Field, New Mexico
Authors: Bödvarsson Gudmundur S. , Vonder Haar Stephen P. , Wilt Michael J. , Tsang Chin Fu 
Published: December 2007

ABSTRACT
A 50 MW geothermal power plant is currently under development at the Baca site in the Valles Caldera, New Mexico, as a joint venture of the Department of Energy (DOE), Union Oil Company of California and the Public Service Company of New Mexico (PNM). To date, over 20 wells have been drilled on the prospect, and the data from these wells indicate the presence of a high-temperature liquid dominated reservoir. In this paper, data from open literature on the field are used to estimate the amount of hot water in place (reservoir capacity) and the length of time the reservoir can supply steam for a 50 MW power plant (reservoir longevity).
The reservoir capacity is estimated by volumetric calculations using existing geological, geophysical and well data. The criteria used are described and the sensitivity of the results discussed.
The longevity of the field is studied using a two-phase numerical simulator (SHAFT79). A number of cases are studied based upon different boundary conditions, and injection and production criteria. Constant or variable mass production is employed in the simulations with closed, semi-infinite or infinite reservoir boundaries. In one of the cases, a fault zone feeding the production region is modeled. The injection strategy depends on the available waste water. The results of these simulations are discussed and the sensitivity of the results, with respect to mesh size and the relative permeability curves used, are briefly studied.
Pressure Transient Analysis of Geothermal Wells with Phase Boundaries
Authors: Home Roland N. , Satman Abdurrahman , Grant Malcolm A. 
Published: December 2007

ABSTRACT
The analysis of pressure tests in geothermal reservoirs is often complicated by two-phase effects. This paper investigates the effect of a phase boundary at a constant radial distance from the well, produced, for example, by the flashing of a water reservoir during production or by the injection of water into a steam or two-phase reservoir. This configuration may be recognized from a time shift in the buildup (or falloff) semilog straight line, and, in some cases, the distance to the phase boundary can be estimated by plotting the transition pressure response against time on cartesian coordinates. Field data from the Broad-lands geothermal field in New Zealand confirms the applicability of the technique and demonstrates that the injected volume (which is known) may be used with the buildup data to calculate porosity and "swept" volume.
The analysis also indicates the possibility of determining compressibility and permeability contrasts across the phase boundary. This enables estimation of the reservoir porosity and relative permeabilities in the two-phase region. In a few cases, wellbore storage effects can disguise the pressure response and make parameter determination more difficult. These cases are discussed.
Economic Sand Control and Stimulation Strategy for Marginal Wells with Limited Reserves
Authors: Morrison T. L. , Smith K. C. 
Published: December 2007

Abstract
This paper presents a detailed case history showing the practical use of monobore and vent-screen completions to produce from reservoirs that are marginally commercial.
Marginal well completions can become a viable economic possibility through (1) advancements using monobore and vent-screen completions, (2) innovative application of sand control products, and (3) 3-D modeling. The three-part completion strategy presented below shows that a sand-control fracture treatment can be economically efficient in marginal wells that would not have historically justified such completion.
Perform the completion process without a rig on location. All elements of the strategy must have this element as a primary consideration. Plan and prepare for the delivery of the completion in a manner that is practical, economic, and timely, so that job quality and safety are not compromised. Integrate new and existing technologies to create a fresh approach to provide economic solutions for both sand control and stimulation of the well.
Rheological Evaluation of Cement Slurries: Methods and Models
Authors: Bannister Charles E. 
Published: December 2007

Abstract
The determination of the rheological behavior of cement slurries is essential for the proper evaluation of displacement pressures and flow rates for optimum cement placement. Several cement slurries have been examined, using pipe flow and concentric cylinder viscometers, in an effort to determine which method is better suited for determining such flow characteristics. Comparative analysis of the data indicates that the concentric cylinder viscometer may be inadequate for measurement of the rheological properties of cement slurries.
Studies using a pipe-flow rheometer indicate that an apparent "slip" at the pipe surface occurs during rheological evaluation of cement slurries. This wall "slip" is attributed to particle migration when cement slurries are sheared. Field evaluation of the rheological properties of cement slurries flowing in large diameter pipes confirm the results of the pipe-flow rheometer.
Based on data obtained with a pipe-flow rheometer, a recommendation is offered as to which mathematical model most accurately describes the flow characteristics of cement slurries.
Multi-Well Operational Optimization for Maximum Production
Authors: Kappos L. , Economides M. J. 
Published: December 2007

Abstract
A typical oil and gas surface production scheme consists of gathering systems where individual wells are connected en route to a common separator. These wells are invariably at differing distances and may also be connected with different size pipelines and other pressure-reducing devices. However, they do have some overriding commonalities: they are all expected to be culminating into a common pressure at the separator and, often, at the other end they also start at a common pressure, that of the reservoir. The latter is time dependent, reflecting reservoir depletion. The production rate greatly depends on the well "plumbing", the surface network and, of course, the fluid properties. The pressure drop depends on the flow rate and the inlet pressure and the system temperature. In such a situation, production engineers have a number of tools at their disposal to maximize the production rate: a more drastic approach is to change the production tubing and/or the surface pipelines, add pumps etc. A more benign approach is to optimize the choke sizes and, especially, anticipate, the time of such choke changes or work in the system a schedule for variable choke adjustments.
We have developed a multi-well network optimization scheme that uses a mathematical solver, which employs a large number of equations, which, when solved simultaneously, allow the finding of the system optimum rate, points towards the appropriate choke sizes (as the reservoir pressure declines) and re-sizes the diameter of the surface network tubulars. We present here both the methodology and example applications for natural gas gathering systems.
Numerical Simulation of the Imbibition Process in Fractured Reservoirs
Authors: Menouar Habib , Knapp Roy M. 
Published: December 2007

ABSTRACT
This paper describes an algorithm for simulating matrix fractured reservoirs. Response curves for individual matrix blocks developed by numerically simulating the inhibition processes in individual blocks for several sets of boundary conditions are coupled in an iterative process to describe vertical water movement and oil production in the simulator. This simulator can be used to estimate the efficiency of water-flooding in matrix fractured reservoirs as a function of reservoir and matrix block description and planned waterflooding rates.
The simulator has been used on an example reservoir to develop some general results and conclusions. For matrix fractured reservoirs, ultimate recoveries will be greater if there are relative few blocks in the vertical direction and flooding rates are kept low. If individual blocks are tall and flooding rates are high low recoveries can be expected. The water oil ratio increases more rapidly in matrix fractured reservoirs after water breakthrough than in homogeneous reservoirs.
An Experimental Investigation of the Effect of the Conductive Matrix on the Physical and Electrical Properties of Saudi Sandstone Reservoir Rocks
Authors: Zaafran Zaher M. , Totonji Ahmad M. 
Published: December 2007

ABSTRACT
Laboratory studies of saturated sandstone samples collected from Saudi Oil Fields showed that the sandstone exhibits conductive matrix. Formation Factor of the reservoir rocks is measured under different water salinities and correlated with rock porosities. A relationship between the Formation Factor and the corresponding water quality is also determined.
The study has its merit not only in electric log interpretation but also in the Study of Fundamental rock Parameters which are of great use in reservoir engineering.
Application of Build-Up Transient Pressure Analysis to Well Deliverability Forecasting in Gas Condensate Reservoirs Using Single-Phase and Two-Phase Pseudo-Pressures
Authors: Bozorgzadeh M. , Gringarten A. C. 
Published: December 2007

Abstract
The ability to predict well deliverability is a key issue for the development of gas condensate reservoirs. We show in this paper that well deliverability depends mainly on the gas relative permeabilities at both the end point and the near-wellbore saturations, and on the reservoir permeability. We then demonstrate how these parameters and the base capillary number can be obtained from pressure build-up data by using single-phase and two-phase pseudo-pressures simultaneously. These parameters can in turn be used to generate gas pseudo-relative permeability curves. Finally, we illustrate this approach with simulated build-up pressure data before applying it to an actual field case.
Deep Ocean Coring - Recent Operational Experiences of the Deep Sea Drilling Project
Authors: Larson Valdemar F. , Robson V. Barry , Foss Glen N. 
Published: December 2007

ABSTRACT
During recent years, many changes and innovations in deep sea drilling techniques and equipment have been required to meet the objectives of an increasingly sophisticated and diversified scientific program. These include such developments as a deep-penetrating hydraulic piston corer, drill string design improvements and a bit releasing mechanism. Methods of deploying instrumentation for specialized geophysical investigations were devised. An additional challenge lay in maintaining the efficiency of the drilling vessel in the face of a research schedule with an increasing amount of on-site time and rising operating costs.
Adding Value through Integrated Research to Unlock the Tight Gas Potential in the Rotliegendes Formation of North-Germany
Authors: Gaupp R. , Liermann N. , Pusch G. 
Published: December 2007

Abstract
The deep Rotliegendes sandstone deposits in North-Germany are estimated to carry natural gas resources of some 300-500 billion cubic meters. The distribution of the diagenetically altered Permian Basin deposits was identified by 3-D seismic survey of 200 square kilometers, well log analyses of 46 exploratory and production wells and of approximately 1200 meters of cores. A scientific analysis and interpretation of this data was achieved in a joint-industry, university and research institutes-project, co-ordinated by DGMK. The most important geologic and geophysical findings can be summarized: Diagenetic patterns correlate with reservoir properties in tectonically controlled compartments. Seismic facies classes distinguish major reservoir characteristics. Early oil (and other HC) migration appears to be a dominant factor in the reservoir quality evolution of the later tight gas reservoirs. Best perme-abilities are encountered in settings with late stage dissolution porosities adjacent to former oil accumulations and migration paths.
No presently open natural fracture systems have been identified in the tight formation. The extremely low permeability of less than 600 micro-Darcies of the rock matrix under in-situ stress conditions requires the application of horizontal well technology combined with multiple hydraulic fracturing, which could be used successfully in many cases, although less successful tests have been reported.
The water sensitive rock can entrap fracture fluid filtrate, which damages the potential productivity of the fractured wells (hydraulic skin). The key parameters of this rock-liquid inter-action-the interfacial tension and the liquid mobility-have been identified by numerical simulation as being responsible for sustaining hydraulic skin effects. Solid production in form of illite fines as well as broken quartz grains in the early production phase of the fractured wells indicates a further potential form of productivity damagea mechanical skin, induced by the disintegration of the rock during the dilatant deformation in the fracture pressure build-up phase.
Evaluating Uranium Deposits for Solution Mining
Authors: Stover Dennis E. 
Published: December 2007

ABSTRACT
In situ leaching of uranium has rapidly developed into a commercial technology. The extent of this development is typified by the fact that many mining feasibility studies now routinely examine in situ leaching as well as the conventional shaft and open pit options.
A methodology for evaluating the leachability of a uranium ore body is presented. Extensive coring of the ore body and testing of ore samples are necessary to establish the quality, quantity, and leachability of the ore. A testing program which provides the necessary data in a rapid, yet thorough fashion, is discussed.
Pumping Well Analysis
Authors: Alexander Lloyd G. 
Published: December 2007

ABSTRACT
This paper presents a new, patented1,2 approach to the testing and evaluation of a pumping oil well.3 For an actively pumping well, the test provides the flowing bottom-hole pressure, the flow rate at which gas is liberated up the annulus, and the pumping rate of the bottom-hole pump.
When the well is shut in, the technique can be used to determine the bottom-hole pressure as a function of time. This information can be used in conventional pressure-buildup analysis for damage, transmissibility, and static pressures.
Regulatory Impacts on Major Energy Projects
Authors: Barton Hugh B. , Hester Carl T. 
Published: December 2007

ABSTRACT
Environmental laws and other regulatory restraints have seriously hampered progress toward achieving national objectives of greater energy self-sufficiency. Significant energy projects have been stymied by the instability of regulations and erosion of economic liberties. Although there are encouraging signals of a move toward a more practical regulatory climate for the energy industry, advocates of this movement must support it strongly while the momentum is building. Several definitive methods are suggested as potential avenues to re-establish a greater degree of economic freedom so important to the long-term strength of our nation.