bluuebunny/crossref_metadata_2025_split huggingface dataset:
A Simplified Performance-Predictive Model for In-Situ Combustion Processes
Authors: Genrich J. F. , Pope G. A. 
Published: December 2007

SummaryA one-dimensional (ID) model to perform rapid calculations of fluid production history for dry and wet forward insitu combustion processes is presented. The predominantly explicit, discrete timestep formulation divides the reservoir into four zones of constant properties, separated by shock fronts. Model results are compared with a ID simulator study of a combustiontube experiment and with field data from the Suplacu de Barcau project.
Improved Estimation Algorithms for Automated Type-Curve Analysis of Well Tests
Authors: Barua J. , Horne R. N. , Greenstadt J. L. , Lopez L. 
Published: December 2007

Summary
The analysis of well-test data by automated type-curve match by use of computers is a subject of current interest. Although the automated type-curve-matching technique is often an improvement over conventional methods, there are certain practical problems that occur in its application. Except in the case of a homogeneous reservoir, many reservoir models require the estimation of several parameters. Unless the initial guess is very good, the estimation procedure for many parameters may fail to converge. Even in cases that have only a few parameters, contours of the objective function show that some parameters are inherently ill-defined.
To date, most applications have used the Gauss method or its modifications, such as the Levenberg-Marquardt algorithm. The Newton method should be better suited to the estimation of ill-defined parameters because it uses a search direction that is aligned in the direction of these parameters. This study investigates the application of the Newton method (and an important modification. the Newton-Greenstadt method) to automated well-test analysis. It shows that the added expense of the Newton-Greenstadt method is often justified by the improvement in performance achieved. In many cases, the Newton-Greenstadt procedure converges almost as fast as the Gauss-Marquardt method, yet is more reliable in cases where one (or more important, more than one) parameter is ill-defined.
Study of Subcritical Flow Through Multiple-Orifice Valves
Authors: Surbey D. W. , Kelkar B. G. , Brill J. P. 
Published: December 2007

Summary
Increased oil and gas production from offshore areas and hostile environments has led to a greater use of multiple- orifice-valve (MOV) wellhead chokes. Unlike conventional wellhead chokes, MOV's can be adjusted to any given choke area while under pressure, allowing wells in remote locations to be controlled from a central site. Data on the behavior of multiphase flow through MOV chokes have not been available in the past. This study investigated high-pressure (400 to 800 psia [2.8 to 5.5 iMPa]), two-phase air/water flow through a 2-in. [5.1-cm] MOV choke. Single-phase air and water data were obtained to determine the valve-sizing coefficient, Cv. A correlating parameter was determined with two-phase data to predict the subcritical two-phase pressure drop. This parameter was found to be a function of the gas/liquid ratio, upstream pressure, and choke opening. A mathematical model based on experimental observations was developed to predict the subcritical pressure drop across the choke for single-phase liquid flow.
Influence off Microporosity on the Evaluation off Hydrocarbon Saturation
Authors: Worthington Paul F. , Pallatt Nadia , Toussaint-Jackson John E. 
Published: December 2007

Summary
Saturation exponents, determined from electrical measurements on core plugs desaturated with air as the displacing fluid, are influenced by pore size and pore-size distribution. This influence, which manifests itself through the resistivity index, is most pronounced in microporous rocks. Two controlling factors are electrical tortuosity and surface conduction effects, both of which increase as the electrolyte-filled pore volume (PV) is reduced. Theoretical and experimental data have indicated that the saturation exponent can increase or decrease during desaturation, depending on how these factors interrelate. With due caution, the risk of errors in estimates of hydrocarbons in place caused by the use of an inappropriate saturation exponent can be greatly reduced.
Determination of Lithology From Well Logs by Statistical Analysis
Authors: Busch J. M. , Fortney W. G. , Berry L. N. 
Published: December 2007

Summary
This paper presents a method of predicting lithology by statistical analysis of wireline log measurements with calibration to a core lithology standard. Although an example of the technique applied to the Shublik formation of the Prudhoe Bay area, North Slope, AK, is developed and presented, the method can be applied to any field where some core has been taken. The Shublik, a complex mixture of seven clastic and carbonate rock types, presents a common problem: how can the rock lithology best be identified from wireline logs? During recent work on the reservoir description of the Shublik, it became necessary to answer this question.
A lithology standard must be available to calibrate against during development of a log model of lithology. For the Shublik, the core available provided an excellent sample of the total formation. Using the statistical technique of discriminant analysis, we were able to evaluate a number of log models and to choose the most appropriate one. The final log model chosen for the Shublik formation works quite well and correctly predicts lithology 75% of the time.
Infill Drilling in a Steamflood Operation: Kern River Field
Authors: Restine J. L. , Graves W. G. , Elias R. 
Published: December 2007

Summary
An infill well program involving 574 wells in previously steamflooded idle reservoirs proved to be economical and increased recovery in some areas from 50 to 58%. These wells were recompleted to zones under active steam drive and showed similar recovery increases in addition to acceleration of reserves. These increases in recovery were attained without additional fuel.
Waterflood Calculations for Multiple Sets of Producing Wells
Authors: Hovanessian S.A. 
Published: December 2007

Abstract
The method of characteristics which reduces the Buckley-Leverett nonlinear, partial differential equation to two first-order, linear differential equations is applied to the solution of a water flood recovery problem for multiple lines of producing wells and one line of injection wells. The application of the method is described by a numerical example, and a brief theoretical background is given. From the results of this study, it is concluded that the cumulative water injected and oil produced are the same for single and multiple sets of producing wells.

Introduction
In this paper, the method of characteristics is applied to the solution of a waterflood recovery problem with multiple lines of producing wells and one line of injection wells. The application of the method to this type of recovery problem considerably simplifies the procedure of obtaining a numerical solution. It differs from the method described by Kern because it eliminates the need for integration in obtaining saturation fronts. In addition, the saturation history at any location within the field is obtained from a single diagram (time vs distance with saturation as a parameter).
The paper includes a brief theory of the method of characteristics and its application to the solution of oil recovery problems. A numerical example is worked out, and the cumulative oil recovery-vs-time curve for a system with multiple sets of producing wells is obtained. This curve is then compared with the recovery curve of a system with only one set of producing wells.
From this study, it is concluded that the cumulative water injected and oil produced are the same for single and multiple lines of producing wells. However, the recovery time is considerably longer for multiple sets of producing wells.
Improved Magnetic Model for Determination of Range and Direction to a Blowout Well
Authors: Jones Douglas L. , Hoehn Gus L. , Kuckes Arthur F. 
Published: December 2007

Summary
Magnetic logs are commonly used in wild-well kill operations to guide a relief well to a blowout well. Estimates of distance and direction to the blowout well are highly dependent on the assumed magnetic model of the blowout well casing. Theoretical and experimental results show that the magnetic poles of a long magnetized cylinder fit an exponentially distributed model rather than the standard impulsive-pole model. Magnetic techniques for determining range and direction from a relief well to a blowout well are explained, and modifications of these techniques based on the new magnetic model are developed. The techniques presented here can be used during drilling operations with data from most measurement-while-drilling (MWD) tools. Substantial improvements in range estimates are achieved for near- and medium-range targets.
A Management Look at Natural Gas
Authors: Golush W.B. 
Published: December 2007

Abstract
Natural gas is a major factor in the domestic petroleum industry and should command wellhead prices commensurate with its impact on the energy markets. By 1968 gas is predicted to supply 72 per cent of the petroleum energy consumed in those markets where gas and hydrocarbon liquids are in competition with each other. Industry must intensify its exploration efforts to find an annual average of 26 trillion cu ft of gas over the next 10 years. This is needed to back up the predicted 5 per cent annual increase in gas demand. Unit expenditures for finding and developing petroleum hydrocarbons have increased at a faster rate than have unit wellhead revenues per million Btu of combined domestic crude oil and natural gas production. In fact, at constant dollars, unit revenues for combined wellhead production have decreased. Wellhead prices ranging from 18 to 25 cents/Mcf for new gas contracts seem to offer the incentive to explore for and to develop gas reserves. The average wellhead price in 1958 of 11.9 cents/Mcf on all gas must rise to 18 to 20 cents within three years and to 25 cents within 10 years to sustain intensified exploration activities. In addition to firmer prices on new gas commitments, producers must receive higher prices on gas delivered under older contracts. In both cases, Federal regulation of about 65 per cent of the marketed gas production presents a number of uncertainties. Pending an acceptable solution to the regulatory problem, producers should aggressively pursue natural gas activities. Exploration should be concentrated in areas offering the required incentive prices. Sales should be made preferentially into non-jurisdictional markets, or to those interstate markets offering the greatest wellhead revenues.

Introduction
There are some 6,000 producers in the United States who sell significant quantities of natural gas and who are not primarily engaged in the operation of interstate gas pipelines. These "independent producers" sell gas in both interstate and intrastate commerce and are heavily engaged as well in crude-oil finding and development.
New Production Logging Technique for Horizontal Wells
Authors: Joly E. L. , Dormigny A. M. , Catala G. N. , Pincon F. P. , Louis A. J. P. 
Published: December 2007

Summary
A new technique for running production logs in horizontal wells has been developed. The logging tools attached to a rigid stinger are pumped down a service tubing until they reach the zone to be logged. This paper describes the new technique and the first two case histories, Lacq 91 (France) and Rospo Mare 6 (Italy).
Liquid Holdup in Wet-Gas Pipelines
Authors: Minami K. , Brill J. P. 
Published: December 2007

Summary
An experimental study of two-phase flow was conducted to investigate liquid holdup in wet-gas pipelines. The liquid-holdup data were obtained by passing spheres through a 1,333-ft [406.3-m] -long, 3.068-in. [77.93-mm] -ID horizontal pipe and measuring the liquid volumes removed. Three different two-phase mixtures were used.
The holdup data were compared with predicted holdup values and were used to evaluate a mechanistic model for stratified flow. None of the methods could accurately predict liquid holdup in this low-holdup region.
Two new empirical liquid-holdup correlations for horizontal flow were proposed. The first is strictly for wet-gas pipelines (0&lt;yL &lt;0.35); the second is for any horizontal pipeline (0&lt; yL&lt;1.0).
Retrieving Stuck Liners, Tubing, Casing, and Drillpipe With Vibratory Resonant Techniques
Authors: Gonzalez Orlando J. 
Published: December 2007

Summary
This paper discusses the constructive use of resonant power transmission down the axial length of a stuck oilfield tubular for the purpose of extracting the tubular from inadvertent (e.g., stuck drillpipe or tubing) or purposeful (e.g., gravel-packed liners) confinement. Resonant and nonresonant oilfield systems are examined with appropriate field measurements of resonant parameters.
Transverse Dispersion in Slug-Mode Chemical EOR Processes in Stratified Porous Media
Authors: Wheat Michael R. , Dawe Richard A. 
Published: December 2007

Summary
Transverse dispersion in multilayered media of moderate permeability contrast has been examined experimentally and theoretically. Continuous and slug-mode displacements at unit and nonunit mobility ratios have been conducted in a layered beadpack model with a permeability contrast of approximately 3:1. Layer-width and residence-time effects have been quantified and scaled to core and reservoir dimensions. Transverse dispersion can be significant for reservoirs with layers less than 100 cm [40 in.] thick and core material with layers less than 1 cm [0.4 in.] thick. The data can be used for validating simulation packages written for chemical dispersion.
Patterns of Permeability in Eolian Deposits: Page Sandstone (Jurassic), Northeastern Arizona
Authors: Goggin D. J. , Chandler M. A. , Kocurek G. , Lake L. W. 
Published: December 2007

Summary
The eolian, Jurassic Page sandstone of northeastern Arizona is marked by a highly ordered heterogeneity. The heterogeneity is expressed by the intricate association of stratification types, which are a direct result of the depositional processes. The dominant stratification types in eolian reservoirs are grainflow, grainfall, and wind-ripple deposits, which form on the lee faces of migrating dunes; interdune deposits, which form between migrating dunes; and extra-erg deposits, which occur sporadically when other depositional environments encroach upon an eolian system. These stratification types each have a unique permeability range, which implies that the fluid migration routes in eolian reservoirs will be dictated by the geometry and types of stratification present.
One of the most important aspects of this study is the correlation of qualitative geologic descriptions with quantitative variables such as permeability. About 2,000 measurements were made with a field minipermeameter on an outcrop of the Page sandstone. These data show that three distinct permeability modes directly relate to the different stratification types.
Permeability exhibits two components of variation: a structural or systematic component and a random or noise component. In this context, the structural component may be correlated to identifiable geologic processes, whereas the random component covers all unexplained variations. These definitions, however, are entirely scale dependent. That is, by decreasing the scale of measurement, structure is revealed in the random variation. This scale dependence is evident in the subject outcrop and, using several statistical tools, we are able to illustrate the "nested" nature of the spatial variation in permeability.
Interpretation of Miscible Displacements in Laboratory Cores
Authors: Bretz Robert E. , Orr Franklin M. 
Published: December 2007

Results of stable, first-contact miscible displacements are presented for three San Andres carbonate cores from west Texas and eastern New Mexico. All three cores showed evidence of significant heterogeneity at the core scale. Effluent composition measurements were interpreted with two relatively simple models of mixing during flow in heterogeneous porous media: the Coats-Smith (CS) model, which represents the pore space as flowing and stagnant fractions with mass transfer between them, and a porous sphere (PS) model, which describes flow between an assemblage of porous spheres with diffusive interchange of material in the spheres with fluid flowing past them. Parameters for the two models are reported and compared. Direct measurements of some parameters from thin-sections agreed well with least-error parameters for one sample for which comparisons were possible. PS model fits showed less error than CS model fits.The form of the PS model is then used to examine how mixing effects change with changes in flow velocity, displacement length, the length scale associated with heterogeneity, and the rate of exchange of material between flowing and stagnant zones. We conclude that for reservoirs with scales of heterogeneity larger than those present in core samples, laboratory core displacements do not provide evidence about mixing behavior at field scale.
Analysis of Heavy-Oil Immiscible CO2 Tertiary Coreflood Data
Authors: Mayer E. H. , Earlougher R. C. , Spivak Allan , Costa Alexander 
Published: December 2007

Summary
This paper describes the results of a series of tertiary, immiscible, CO2 corefloods of Wilmington field Pliocene reservoir rock containing heavy oil (±14°API [+0.97 g/cm3] and±480 cp [+480 mPa-s]). An initial set of corefloods defined the recovery potential of the CO2 injection, while a series of later tests served to define the process more accurately as applied in the field. In an attempt to understand the displacement mechanism, simulator matching of one of the later, more refined groups of corefloods was performed. The corefloods and simulator work indicate that the incremental recovery is more than can be accounted for by oil-viscosity reduction and crude-oil swelling. The improved performance is attributed to more favorable displacement characteristics and the presence of a free gas saturation in the cores.
In-Situ Combustion in the Lower Hospah Formation, McKinley County, New Mexico
Authors: Struna Stephen M. , Poettmann Fred H. 
Published: December 2007

Summary
In 1980-81, Tenneco Oil Co. conducted an in-situ combustion pilot test on the Lower Hospah formation of the South Hospah field, McKinley County, NM. Although the reservoir appeared to be an excellent candidate for in-situ combustion, the pilot project recovered only a very small amount of incremental oil and was terminated as a consequence.
To evaluate the pilot test and to determine the reasons for its performance behavior, a reservoir model of the test site was developed from the historical performance of secondary recovery operations in conjunction with available log and core data. The result was a three-layer, four-quadrant model of the test site. The volumetric sweep efficiency of the combustion front was estimated from two interior core holes drilled after the project was terminated. This resulted in a postcombustion model of the test site depicting the vertical sweep of the combustion front.
Stoichiometric relationships were used to evaluate the combustion performance of each layer of the model. The stoichiometric evaluation provided a means to compare quantitatively the postcombustion reservoir model with actual test performance, thus verifying the model. The project failed because the combustion front migrated beneath the oil zone, processing an interval containing low oil saturation and resulting in very large air/oil ratios.
Review of CO2 Flood, Springer "A" Sand, Northeast Purdy Unit, Garvin County, Oklahoma
Authors: Fox Michael J. , Slmlote Vishnu N. , Stark Kelly L. , Brinlee L. D. 
Published: December 2007

Summary
This paper describes the response of a CO2 flood in the Northeast Purdy Springer "A" Sand Unit in Garvin County, OK. Various aspects of field operations are discussed, including surface handling of the CO2 production stream, measurement and treatment of produced fluids, corrosion and pump problems, effects of high CO2 production seen downhole, and solutions to alleviate these problems. Several patterns in the project have received the full designed CO2 slug size of 30% of initial HCPV. On the basis of individual pattern response, operational and design changes were made to enhance the production performance of the flood area. Results of a time-lapse well-logging program are shown, along with comparisons of injection profiles taken before CO2 injection, during CO2 injection, and during post-CO2 water injection. Production response for several wells is shown and compared. The information and operating philosophy presented is based on operating experience before 1985.
CO2 Diversion With Foam in an Immiscible CO2 Field Project
Authors: Holm L. W. , Garrison William H. 
Published: December 2007

Summary
A foam emplacement technique was applied through one well in the tar zone of Fault Block V in the Wilmington field to improve the distribution and sweep efficiency of injected CO2. The Long Beach Oil Development Co. is conducting an immiscible CO2/N2 water-alternating-gas (WAG) flood in this waterflooded, heavy-oil reservoir. Laboratory studies showed reduction in CO2/N2 gas mobility and improvement in overall sweep of laboratory cores by the addition of Alipal CD-128 foaming agent during the gasflood.
The field application of the foaming technique was successful in diverting the gas to a previously unswept interval, but subsequent injection of water diluted the foam to the extent that it lost its effectiveness.