bluuebunny/crossref_metadata_2025_split huggingface dataset:
Extension of the Generalized Dykstra-Parsons Technique to Polymer Flooding in Stratified Porous Media
Authors: Mahfoudhi Jalel E. , Enick Robert M. 
Published: December 2007

Summary
This paper presents an analytical solution for oil recovery from a stratified reservoir during a polymer flood. Although the model used in the derivation does not incorporate several of the mechanisms and characteristics of an actual polymer-flooding displacement process, the analytical solution provides some interesting information concerning the effects of slug sizes, gelling, and permeability reduction. Computational costs are very small for the program.*
Constant-Pressure Production in Solution-Gas-Drive Reservoirs: Transient Flow
Authors: Camacho-V. Rodolfo G. 
Published: December 2007

Summary
This paper presents procedures to obtain reservoir parameters from constant-pressure drawdown data in solution-gas-drive reservoirs. A novel procedure to determine the mechanical skin factor is introduced. Examples, including a field case, illustrate the use of this procedure. An estimate of the drainage area can be obtained with the derivative of rate data. A theoretical basis for analyzing data by the pressure-squared, p2, approach is presented; this procedure permits the approximate determination of sandface effective permeabilities in the transient flow period. For damaged wells, it is possible to obtain rough estimates of the size of the skin zone and the ratio of reservoir/skin-zone permeability when early transient data are available. The expression of the appropriate dimensionless rate in terms of physical properties for solution-gas-drive systems is presented. Finally, this paper presents a procedure to obtain an estimate of the change in sandface saturation during the transient flow period.
Organic Deposition From Reservoir Fluids: A Thermodynamic Predictive Technique
Authors: Kawanaka Seldo , Park S. J. , Mansoori G. A. 
Published: December 2007

SummaryA molecular model is developed to predict onset and amount of organic deposition from reservoir fluids caused by variations in temperature and pressure and introduction of miscible solvents. The model is used successfully to predict the phase behavior and deposition regions of asphaltene in CO2/oil mixtures.
Use of a Monte Carlo Method To Simulate Unstable Miscible and Immiscible Flow Through Porous Media
Authors: Hughes D. S. , Murphy P. 
Published: December 2007

Summary
A Monte Carlo solution technique has been implemented within the framework of an implicit-pressure, explicit-saturation (IMPES) simulator for two-phase, or two-component, flow. The saturation equation is interpreted as a probability density function and solved statistically. This automatically triggers an unstable solution when the mobility ratio is unfavorable, thereby mimicking the instability produced by heterogeneities in the porous medium. Results are presented for linear and one-quarter five-spot miscible and immiscible problems.
Preconditioning Concepts in Polymer Flooding in High-Salinity Reservoirs: Laboratory Investigations and Case Histories
Authors: Sohn Wolfgang O. , Maitin Balram K. , Volz Hartwlg 
Published: December 2007

Summary
In polymer-flood field projects with partially hydrolized polyacrylamide (PH PAA) solutions, Deutsche Texaco A.G. (DTA) has applied two methods of preconditioning: a preflush with fresh water and the use of a relatively small slug of a less-salt-sensitive polymer. Results of laboratory work that led to an improved preconditioning concept with polymer are described. Case histories of two projects with two different preconditioning processes are presented and discussed in detail.
Analysis of Uncertainties in Applying the Waxman-Smits Equation to the Determination of Remaining Oil Saturation
Authors: Rackley S. A. , Tannemaat R. J. 
Published: December 2007

Summary
An analysis of the Waxman-Smits equation is presented that describes how uncertainties in the input log data and evaluation parameters affect computed water saturation, Sw, values, taking into account the interdependence of uncertainties that arises when intermediate parameters in the evaluation (water resistivity and excess clay conductivity) are derived from log data. The analysis is applied to the evaluation of remaining oil saturation from openhole logs taken in a number of reservoirs in the Baram delta, offshore Sarawak, Malaysia. When an original water zone is available for the determination of intermediate parameters in these formations, it is concluded that remaining oil saturation in the 0.10- to 0.30-PV range can be determined with a standard deviation of ≈0.04 PV from openhole logs.
A comparison with core-measured Sor values indicates that laboratory measurements and log-derived results differ significantly in these reservoirs. In one field example, this difference is attributed to reservoir inhomogeneity and the averaging inherent in the logging-tool resolution. In a second example, there is evidence that the discrepancy is a result of continued oil drainage after water breakthrough, which may be attributed to a mixed-wettability condition in the reservoir.
Accurate Prediction of Compressibility Factors by the GERG Virial Equation
Authors: Jaeschke Manfred , Audibert Serge , van Caneghem Patricia , Humphreys A. E. , Janssen-van Rosmalen Renée , Pellei Quinto , Schouten J. A. , Michels J. P. J. 
Published: December 2007

Summary
The European Gas Research Group (GERG, Groupe Européen de Recherches Gazières) performed an extensive research project involving the measurement of compressibility factors of pure gases and binary mixtures and of natural gases in the temperature range of 265 to 335 K and at pressures up to 12 MPa. These pure gas and binary mixture data, together with high-quality data from the literature, were used to develop the GERG virial equation for the accurate prediction of the compressibility factor of natural gas (multicomponent) mixtures. Pressure, temperature, and a 13-component composition are used as input data. Eighty-four sets of experimental natural gas data made up of more than 4, 000 data points were used to validate the GERG virial equation of state (EOS). The target accuracy of the GERG virial equation is ±0.1 %. A comparison of experimental and predicted compressibility factors shows that this target was achieved. The average root-mean-square (RMS) error for the differences between the experimental and the predicted compressibility factors is 0.06% for pressures up to 12 MPa. Even in the high-pressure range between 8 and 12 MPa, the RMS error is only 0.07%.
Daily Morning Production Report System
Authors: Branch H. O. , Breaux K. A. 
Published: December 2007

Summary
This paper describes a PC-based database system used by Chevron U.S.A.’s Eastern Region to input, store, gather, and report daily oil and gas production information from remote field locations. The system provides the following functions.
Data input at any location with data-integrity checks. Automated data transfer between locations by modem using in-place company telecommunications facilities. Data aggregation at field, base, and divisional levels. Retransmission of any data changes to appropriate locations. Compiled program written in DBASE III™. "User-friendly" menu interfaces. Fast report generation using arrays.
The system, known as the daily morning production report (DMPR), replaces faxing of paper between locations. The DMPR system is faster than the old reporting method and allows data to be sent to the mainframe computer or outloaded to spreadsheets. The DMPR system reduces the time needed for generating production data reports for operations management.
The data-gathering system is set up so that field locations enter and validate the data and generate reports. The field data are automatically sent to a shore base location and aggregated with data from other fields, analyzed, and reported on. Shore base locations send the aggregated data to the division office, where the data are further aggregated and stored and reports are generated for management. Reports may be produced at any location. Telecommunication is managed by commercially available software and is initiated within the program. The user does not need to leave the program to perform any of these functions.
This paper covers database and program design, program installation, user training, and field experience with the DMPR system.
Subsea Systems of the Argyll Area Fields
Authors: Huber D. S. , Burnett R. C. 
Published: December 2007

Summary
This paper highlights the major subsea/subsurface systems and equipment installed over the past several years in the Argyll area fields that have resulted in extended field life. Three major innovations emphasize the design philosophy of minimizing cost while maximizing flexibility, reliability, and the use of simple, existing technology. Details include the pioneering installation of gas lift, waterflooding of the Duncan field with its unique manifold system, and remote tie-in of wells 9 miles [14 km] away with a simple hydraulic system.
Seeking Engineers in the Sellers' Market
Authors: Stacy T. Don , McCain William D. 
Published: December 2007

Abstract
A common goal of the recruiting efforts of the various petroleum companies is to supply their needs for engineering manpower. Within this common purpose four recruiting techniques are used. These techniques may be described as the Miles Standish Method, the Combination Mode, the Lothario Approach and the Back Door Path. Each technique is described and evaluation of the effectiveness of each is given. A definite correlation is shown between the recruiting technique employed and the success of the company in attracting young engineers.
The basic principle underlying the success of any recruiting program is the exhibition of a sincere personal interest in each candidate. Observation over a period of years indicates that there are both a wrong and a right recruiting approach.
The paper outlines observations of how certain actions affect the student and his opinion of a company. Salaries, telephone communication, choice of assignment, plant visits, recruiting gimmicks, on-campus interviews, organization charts and other factors, are discussed.

Introduction
In no case is the struggle of supply and demand more severe than when the product is a prospective employee. As long as engineering enrollments are low, and industry demand is high, this struggle remains acute. The major oil companies must compete with graduate school, military service, and other industries in filling their needs for engineering manpower. Every recruiter wonders "what went wrong" when a promising young engineer accepts the offer of another company. We have observed the recruiting merry-go-round for several years and have noted that although the companies visiting our campus use the same general approach, the degrees of their success vary widely.
The general program for recruiting engineers follows a pattern of: on-campus interviews, interview trips by the engineering student and follow-up. The major difference among the would-be employers is each one's specific application of this general program. This paper attempts to classify the recruiting techniques and correlate them with their success in the hiring of engineers.
A direct contrast is drawn between the unsuccessful and the successful methods of handling engineering students.
Threshold Pressure Phenomena in Porous Media
Authors: Thomas L.K. , Katz D.L. , Tek M.R. 
Published: December 2007

Abstract
Threshold displacement pressures are needed to determine how much overpressure can be used in storing natural gas. An experimental technique for determining threshold pressures by displacing water with gas from samples saturated with water is presented. Threshold pressures for eight low permeability samples were measured. Threshold pressure data obtained in this work, plus data on higher permeability samples reported in the literature, are correlated with porosity, permeability, surface tension and formation resistivity factor, Mercury injection pressures also were measured and correlated with air-water threshold pressures. Threshold pressures were found to be independent of time.
An aerial photograph of gas emerging from The top of a core shortly after its threshold pressure has been exceeded shows that the gas bubbles we uniformly distributed across the face of the core. Channeling will occur, however, when an increased gas phase permeability is reached.
A porous medium can be resealed after its threshold pressure has been reached provided it has not been desaturated below a fixed saturation. Its new threshold pressure will be lower than when the sample is 100 percent saturated with water.

Introduction
The degree of overpressure in excess of the discovery pressure that a gas storage reservoir can withstand is determined by the ability of its caprock to contain gas, providing the pressure does not exceed the structural limit of the reservoir. The retention of gas in a reservoir by a caprock saturated with water is a result of the capillary forces acting at the gas water interface. Without the presence of water in a caprock, gas would leak out of the reservoir at a rate determined by the permeability of the caprock to gas.
The ability of a caprock to contain gas is expressed in terms of its threshold displacement pressure, which is defined as the minimum pressure needed to initiate the displacement of a wetting phase by a nonwetting phase from a porous medium 100 percent saturated with the wetting phase.
The gas industry must be able to predict how much "overpressure" a gas reservoir can withstand before leakage occurs by gas displacing water from caprock overlying the reservoir. This is of economic importance since the storage capacity of a gas reservoir is proportional to its pressure.
The discovery pressure for most reservoirs is found between the upper and lower limits shown in Fig. 1. Discovery pressures in excess of their hydraulic pressure gradient are attributed to the compaction of an isolated shale formation by the overburden. The lower limit of 0.433 psi/ft corresponds to the weight of the overburden, the gradient of the rock itself.
Insights on Rheological Testing and Flow Behavior of Delayed-Crosslinked Fracturing Fluids
Authors: Cameron J. R. , Gardner D. C. , Veatch R. W. 
Published: December 2007

SummaryOur research findings show that the rheology of delayed-crosslinked fracturing fluids depends not only on the shear and thermal histories, but also on flow geometry, stress level, and time. These gels can flow as nonhomogeneous fluids and have an as yet unreported stress-state (phase) transformation property. These phenomena currently are not accounted for in gel testing or data scale-up but can manifest themselves in apparent test-geometry and time dependencies. This research also indicates that delayed-crosslinked fracturing fluids may give better proppant transport than expected.
Treatment of Variations of Composition With Depth in Gas-Condensate Reservoirs
Authors: Wheaton R. J. 
Published: December 2007

Summary
Considerable variations of hydrocarbon composition with depth have been reported in several North Sea gas-condensate fields. Within the gas phase, the mole fraction of methane present, for example, may change by several percent between the top and bottom of the field. These compositional gradients can cause dewpoint variations of as much as 4 psi/ft [90 kPa/m]. Neglect of these effects in simulation will lead to significant errors in the estimates of hydrocarbons initially in place. These errors can, in turn, cause errors of up to 20% in predicted cumulative oil production in some condensate fields. In this paper, we develop a theoretical treatment of variations of composition with depth in hydrocarbon reservoirs. Results of sample calculations show the type of results predicted by the theory and the extent of the errors that may occur if compositional gradients are neglected.
Experimental and Theoretical Investigation of Methane-Gas-Hydrate Dissociation in Porous Media
Authors: Youslf M. H. , Abass H. H. , Selim M. S. , Sloan E. D. 
Published: December 2007

Summary
Vast quantities of natural gas deposits exist in the form of solid hydrates. Methane gas hydrate was formed and dissociated for the first time in Berea core samples. A three-phase ID model was developed to simulate the process of gas production from Berea sandstone samples containing methane hydrate by means of a depressurization mechanism. The model closely matched the experimental data of gas and water production, the progress of the dissociation front, and the pressure and saturation profiles.
Characterization of Fluvial Sedimentology for Reservoir Simulation Modeling
Authors: Henriquez Adolfo , Tyler Kelly J. , Hurst Andrew 
Published: December 2007

Summary
This paper presents a critical study of a 3D stochastic simulation of a fluvial reservoir and of the transfer of the geological model to a reservoir simulation grid. The stochastic model is conditioned by sand-body thickness and position in wellbores. Geological input parameters—sand-body orientation and width/thickness ratios—are often difficult to determine, and are invariably subject to interpretation. Net/gross ratio (NGR) and sand-body thickness are more easily estimated. Sand-body connectedness varies, depending on the modeling procedure; however, a sedimentary process-related model gives intermediate values for connectedness between the values for a regular packing model and the stochastic model. The geological model is transferred to a reservoir simulation grid by use of transmissibility multipliers and an NGR value for each block. The transfer of data smooths out much of the detailed geological information, and the calculated recovery factors are insensitive to the continuity measured in the geological model. Hence, we propose improvements to the interface between geological and reservoir simulation models. Input for our conditional, statistical, sedimentary, process-related model includes regional geological parameters (rates of subsidence and aggradation and grossly contoured paleotopography) and local values (depth, thickness, and direction and width of sand bodies ascertained from well-test and core analyses). Integration of sedimentological understanding of the reservoir's depositional environment is emphasized.
Valid Capillary Pressure Data at Low Wetting-Phase Saturations
Authors: Melrose J. C. 
Published: December 2007

Summary
Air/brine capillary pressure data obtained by three different techniques are reported as a function of saturation for several Berea core-plug samples. The capillary pressure values ranged from about 0.67 to 9.5 MPa [97 to 1, 380 psi]. The corresponding brine saturations ranged from 10 to 3% PV. The techniques used were high-speed centrifuge, porous plate, and water-vapor desorption (WVD). The results show that a plot of log Pc vs. log Sw is linear in the saturation range studied. These data are believed to be the first valid capillary pressure data reported for Berea samples in the high-pressure, low-saturation region. Also, no comparable data appear to have been published for any sedimentary rock in the permeability range above 1 md.
Pressure-Transient Analysis of a Composite Naturally Fractured Reservoir
Authors: Satman Abdurrahman 
Published: December 2007

SummaryAn analytical model describing the transient pressure behavior of a well completed in a composite naturally fractured reservoir is presented. This model was derived by extending the naturally fractured reservoir model with unrestricted interporosity flow to a composite reservoir. The composite reservoir has a circular inner region with fluid and rock properties different from those of the outer region. It is a concentric composite model with a finite-radius well located in the center.Two new solutions for analyzing the pressure response at the producing (or injection) well in infinitely large composite and bounded composite naturally fractured reservoirs are given. The results were obtained with the Stehfest algorithm for Laplace-transform inversion. Depending on the reservoir and fluid properties, various semilog straight lines may be observed in a particular pressure/time curve. The pseudo-steady-state approach can be used to determine the swept volume. On the basis of model results for different parameter values, guidelines are provided for conducting and interpreting a pressure test to determine the characteristics of a composite naturally fractured system, provided that wellbore-storage effects do not mask early-time data.
New Solutions for Well-Test-Analysis Problems: Part 2 — Computational Considerations and Applications
Authors: Ozkan Erdal , Raghavan Rajagopal 
Published: December 2007

Summary
Computational considerations in obtaining well responses and pressure distributions for several problems presented in Part 1 are discussed. In addition, new asymptotic expressions for pressure distributions in closed drainage volumes applicable during the boundary-dominated flow period are derived. Interestingly, these expressions, which are much simpler than those available in the literature, can be used to derive shape factors for a variety of completion conditions (vertical, horizontal, and vertically fractured wells). Application of constant-rate solutions to more complex conditions is also presented.