bluuebunny/crossref_metadata_2025_split huggingface dataset:
Novel Breaker/Filtration Process Reduces the Cost of Recycling Viscosified Brine Completion Fluids
Authors: McIntyre James A. , Kalnins John M. , Varjlan Richard D. , Powell John 
Published: December 2007

SummaryA novel process for recycling polysaccharide-viscosified brine completion fluids was developed. The process uses oxidants generated directly in the used brine by electrolysis to "break" the viscosity. The treated brines can be filtered with conventional equipment, reviscosified, and reused. The process has been applied on a laboratory scale to Br-/Cl- brines containing Na+, K+, Ca+2, and Zn+2 cations. Calculations with information from pilot-scale tests on NaBr/NaCl brines indicate that the process should be attractive economically.
Interpretation of Dielectric Permittivity Measurements in the 20- to 50-MHz Frequency Range
Authors: Sherman Michael M. 
Published: December 2007

Summary
Laboratory measurements of the dielectric permittivity in the 20- to 50-MHz (2×107- to 5×107-cycle/sec) frequency range of brine-saturated rocks are difficult to obtain. An interpretation model is introduced in which laboratory measurements in the 100-to 1300-MHz (2×108- to 1.3×109-cycle/sec) range are used to calibrate an interpretation method in the 20- to 50-MHz (2×107- to 5 × 107-cycle/sec) range. The method is illustrated with an example from the Weber formation in Colorado. In the example, movable oil is calculated using one porosity and two dielectric logs.
Comparison of Implicit and Explicit Methods for Interpreting Displacement Data
Authors: Richmond Peyton C. , Watson A. Ted 
Published: December 2007

Summary
The Johnson-Bossler-Naumann (JBN) and related methods for interpreting displacement experiments provide explicit, or pointwise, estimates of relative permeability that must be interpolated or smoothed when entire relative permeability functions are desired. In this paper, we compare relative permeability functions obtained with an implicit (regression-based) method with those estimated with explicit values. We show that the functions obtained with the regression-based method are most consistent with the measured data.
Acoustic Flowmeter Field Test Results
Authors: McBane Richard A. , Campbell Raymond L. , DiBello Edward G. 
Published: December 2007

Summary
The newly developed borehole acoustic flowmeter provides data to locate depth precisely and to quantify gas production from individual gas entries, even when they are spaced closely together, for low-flow-rate gas-producing zones in a typical Devonian shale well in the Appalachian basin. Data from a field test conducted in Aug. 1987 are presented, along with the measurement theory involved. A comparison to a conventional spinner flowmeter on the same well is also presented.
Concrete Hulls for Tension-Leg Platforms
Authors: De Oliveira João G. , Fjeld Svein 
Published: December 2007

Summary
This paper describes the main features of a concrete-hull tension-leg-platform (TLP) concept developed for the Heidrun field in the Haltenbanken area of the Norwegian sector of the North Sea. The hydrodynamic response and the methods adopted to optimize the hull dimensions, as well as the mooring system and hull mechanical outfitting, are discussed first. Then construction methods are briefly described. Inspection, maintenance, and repair are also addressed. Finally, the advantages of the concrete-hull TLP concept are summarized, including the concrete hull's adaptability to a large range of design requirements, low cost, and short construction time. This paper shows that the concrete-hull TLP is a very cost-efficient solution for the development of deepwater fields.
New Gypsum/Polymer Mud System Eliminates Gumbo Problems on Tommeliten Field Production Wells
Authors: Sunde Egil 
Published: December 2007

Summary
A new gypsum/polymer mud system eliminated gumbo problems on Tommeliten field production wells. The success of the system was achieved by use of simple, widely known products, with great emphasis placed on understanding chemical interactions. The selection of rheology and mud weight also contributed to the success. The concept resulted in a 30% reduction in time spent on tripping, circulating, and reaming, and no time was lost because of hole instability when casings were run.
An Efficient and Accurate Model for the Structural Analysis of Threaded Tubular Connections
Authors: Kwon Young W. , Klementich Erich F. , Ko Kwang I. 
Published: December 2007

Summary
A structural analysis model for threaded tubular connections was developed by use of advanced mechanics. This computationally efficient model yields acceptably accurate solutions for stresses compared with other available methods, such as experimental (strain gauge) or finite-element analysis (FEA) procedures. Beam-on-elastic-foundation equations are used to compute stresses caused by the assembly of the connection while the bolt/nut and Lamé equations are used for axial loads and pressures.
A Pore-Level Investigation of Foam/Oil Interactions in Porous Media
Authors: Manlowe David J. , Radke Clayton J. 
Published: December 2007

SummaryDirect visual studies of foam flow in etched-glass micromodels containing residual oil demonstrate that foam decays as a result of breakage of pseudoemulsion films. Foam films collapse whenever nearby thin aqueous films separating gas bubbles and oil rupture. Consequently, surfactant formulation for foam insensitivity to oil in porous media should be based on stabilizing pseudo-emulsion films.
An Approximate Analysis Method for Multiphase Flow Data
Authors: Vo Dyung T. , Raghavan Rajagopal 
Published: December 2007

Summary
We analyze responses in wells producing at constant pressure under multiphase flow conditions and present methods to obtain estimates of effective permeability and the mechanical skin factor. All required information can be obtained from constant-composition expansion (CCE; flash) data, and the influence of relative permeability can be incorporated with Jones and Raghavan's theory. We demonstrate data-analysis procedures for semilog and type-curve techniques. We theoretically justify using liquid flow solutions to analyze multiphase flow responses by type-curve matching, and we discuss the design and application of multistep pressure tests.
Transient Pressure Behavior off Commingled Reservoirs
Authors: Kuchuk Flkri J. , Wilkinson David J. 
Published: December 2007

Summary
This paper presents a new general analytic formulation for pressure-transient behavior of commingled systems (layered reservoirs without crossflow). The formulation includes the effects of surface and downhole flow-rate variations and of wellbore storage resulting from the wellbore volume's location below the flow-rate measuring point (at any location in the wellbore, including the surface and sandface). The method can be applied to a variety of layered reservoirs. Each individual subzone (reservoir) in the system can be different, with different initial and outer-boundary conditions, and each zone can start to produce at a different time. The well completion for each layer can also be different.
New Laplace-domain solutions are presented for partially penetrating slanted wells and partially penetrated wells with and without a gas cap. The solution for slanted wells is based on that of Cinco-Ley et al. but includes the correct effective wellbore radius for the case of an anisotropic formation. Solutions to a few selected commingled systems are also presented to explore the application of the formulation.
Applications of Pulsed-Neutron-Capture Logs in Ekofisk Area Fields
Authors: Corwith Jeffrey R. , Mengel Frank 
Published: December 2007

Summary
Phillips Petroleum Co. Norway is engaged in an extensive reservoir-monitoring program in the seven greater Ekofisk area fields. This program includes pressure-transient testing, production log surveys, compaction monitoring, and pulsed-neutron-capture (PNC) log surveys. This paper describes the applications of PNC logging in the six Ekofisk area chalk reservoirs and the analysis techniques associated with those applications.
Gas has been injected into the upper portion of the Ekofisk reservoir since 1975, and waterflooding was initiated in 1987. These projects complicate PNC log analysis. Water breakthrough reduces or eliminates the "acid effect, " which can mask any increase in water saturation unless the acid-effect change can be quantified. Gas-saturation changes can introduce systematic error in water-saturation calculations unless taken into account. Phillips Petroleum Co. Norway recognized these complications and developed solutions that can be applied as part of the "standard" analysis techniques. Examples of each application are presented.
Evaluation of Accuracy of Estimating Air Permeability From Mercury- Injection Data
Authors: Kamath Jairam 
Published: December 2007

Summary
Published theoretical and correlative models and extensions developed during this study were examined to evaluate the accuracy of predicting air permeability from mercury-injection data. A recently developed statistical technique, bootstrapping, was used to compare different variables for correlation with permeability and to demonstrate that correlations by lithology or by field often are not statistically different.
A Method for Designing Fiberglass Sucker-Rod Strings With API RP 11L
Authors: Jennings J. W. , Laine R. E. 
Published: December 2007

Summary
This paper presents a method for using the API recommended practice for the design of sucker-rod pumping systems with fiberglass composite rod strings. The API method is useful for obtaining quick, approximate, preliminary design calculations. Equations for calculating all the composite material factors needed in the API calculations are given.
Investigation of Retarded Acids Provides Better Understanding of Their Effectiveness and Potential Benefits
Authors: Crowe Curtis W. , McGowan Gerald R. , Baranet Sandy E. 
Published: December 2007

Summary
An automated acid-reaction kinetics tester (ARKT) was developed and used to evaluate various retarded-acid systems. Studies of several commercially available acid retarders revealed that some functioned by depositing hydrophobic films on carbonate surfaces while others were foaming agents that stabilized a CO2 foam barrier on the rock surface. In the absence of filter-cake development, viscosity imparted by the addition of gelling agents had little effect on reaction rate. Emulsification of acid was shown to reduce reaction rate, with the greatest retardation provided by oil-external acid emulsions.
Lisburne Reservoir Limited-Drainage Test: A Pilot Test Case History
Authors: Currier Barbara H. 
Published: December 2007

SummaryPilot tests were run in the Lisburne reservoir before field startup. The second pilot, the limited-drainage test (LDT), obtained production history for a confined producing well, as well as reservoir description and producing-mechanism information. This paper discusses the data gathered and the data interpretation that led to a better understanding of the Lisburne reservoir.
Factors Influencing Unsteady Relative Permeability of a Mixed-Wet Reservoir Rock
Authors: Mohanty K. K. , Miller A. E. 
Published: December 2007

Summary
Capillarity, viscous fingering, and heterogeneity influence the flow in a core plug and hence affect the relative permeability determined from an unsteady test. Several unsteady water/oil relative permeability tests were carried out in a mixed-wet core while in-situ 3D saturation distribution was monitored by a computerized-tomography (CT) scanner. Results illustrate that, in the early part of the Johnson-Bossler-Naumann (JBN) method, relative permeability is dominated by fingering and heterogeneity effects. The later part of this method (&gt; 1 PV), however, represents the relative permeability of the end-face saturation and is influenced by the capillary number and throughput. Thus, laboratory results must be scaled to the field on the basis of the flow parameters: end-effect, capillary, instability, and heterogeneity numbers.
Centrifuge Measurements of Capillary Pressure: Part 1-Outflow Boundary Condition
Authors: O'Meara D. J. , Hirasaki G. J. , Rohan J. A. 
Published: December 2007

Summary
The capillary pressure curve is estimated from centrifuge measurements with the assumption that Pc =0 at the outflow end of the core. With the proper end piece to support the core sample, this boundary condition is valid in practically all circumstances. If the end piece is wetted by the produced liquid, however, experiments show that the capillary pressure curve is altered significantly. Theoretical analysis demonstrates that film drainage can displace the zero-capillary-pressure boundary condition to the bottom of the end piece or farther. Accordingly, we recommend that the displaced phase not wet the end piece; in the case of water, a teflon end piece is recommended over the commonly used rubber one. When the end piece is not a problem, the condition for 100% liquid saturation at the outflow face can be expressed as a critical Bond number, which is rarely exceeded. Saturation profiles for an experiment just below the critical Bond number were in excellent agreement with predictions. Pendant drops at the outflow face can result in a nonzero capillary pressure at the outflow face, but this effect is insignificant. Good agreement was obtained between mercury injection and centrifuge-measured capillary pressure curves. Attention is drawn to the importance of core jacketing, core cleaning, and equilibration times in providing reliable centrifuge-measured capillary pressure curves.
Conditional Simulation of Reservoir Heterogeneity With Fractals
Authors: Hewett Thomas A. , Behrens Ronald A. 
Published: December 2007

SummaryThe displacement efficiency of fluids injected into heterogeneous formations depends on the nature of reservoir-property variations and their spatial correlations. Conditional simulation is a geostatistical technique for creating property distributions, with any desired resolution, that have a prescribed spatial correlation structure and that match measured data at their sampling locations. Conditional simulations of reservoir heterogeneity can be used to address the two major issues in characterizing reservoirs for performance modeling: scaling of flow processes and properties and dealing with the uncertainty resulting from missing information in reservoir descriptions. The correlation structure emphasized in this study is a fractal model. Examples of conditional simulations of areal distributions and vertical cross sections of properties are presented. Simulations of fluid flow through different realizations of the simulated geology are compared with each other and with simulations of fluid flow through more homogeneous distributions derived by lumping parameters into discrete flow units or by smoothly interpolating well-log data. Results show that flow predictions in conditional simulations of the geology have greater fluid channeling, with earlier breakthrough of the injected fluids and less complete sweep of the formation. Flow simulations in multiple realizations of the heterogeneous geology provide a probability distribution of reservoir performance that may be used to evaluate the risk associated with a project caused by incomplete sampling of the reservoir-property distribution.
Experimental Aspects of Partitioning Tracer Tests for Residual Oil Saturation Determination With FIA-Based Laboratory Equipment
Authors: Knaepen W. A. I. , Tijssen Robert , van den Bergen E. A. 
Published: December 2007

Summary
Partitioning tracer tests are used to determine residual oil saturation (ROS). At Koninklijke/Shell Laboratorium, Amsterdam, laboratory equipment based on the flow injection analysis (FIA) method has been constructed for rapid (within 2 hours) and accurate (better than 8%) determination of the equilibrium partition coefficient of tracers between crude oil and brine under simulated reservoir conditions. The apparatus makes possible investigation of the influence of all relevant parameters on the partition coefficient: tracer type and concentration, crude oil type, pressure (up to 34 MPa [4, 930 psi]), GOR's, temperature (up to 150°C [302°F]), and brine salinity. The FIA equipment has been critically evaluated with model compounds. Its versatility has been verified with experimental results obtained on dead and live crudes.
Stochastic Modeling in Reservoir Simulation
Authors: Ding L. Y. , Mehra R. K. , Donnelly J. K. 
Published: December 2007

SUMMARY
This paper outlines details of a method that includes uncertainty in deterministic simulations. The method uses the probability distributions of reservoir and geological properties to obtain a likelihood distribution of the output variables. The Monte Carlo sampling (mcs) method is often applied, but it is impractical for simulation studies because the number of computations becomes excessive. This paper uses an analytical thermal screening model to compare various variance-reduction methods with MCS simulations. The Latin hypercube sampling (LHS) method is then selected to conduct numerical simulations. The methods allow computation of the partial correlation coefficients, which, as demonstrated, can be used to determine the sensitivity of process variables.
Reservoir Studies With Geostatistics To Forecast Performance
Authors: Tang R. W. , Behrens R. A. , Emanuel A. S. 
Published: December 2007

Summary
Example geostatistics and streamtube applications are presented for waterflood and CO2 flood in two low-permeability sandstone reservoirs. The hybrid approach of combining fine vertical resolution in cross-sectional models with streamtubes resulted in models that showed water channeling and provided realistic performance estimates. Results indicate that the combination of detailed geostatistical cross sections and fine-grid streamtube models offers a systematic approach for realistic performance forecasts.
Asphaltene Deposition in Production Facilities
Authors: Thawer Ruksana , Nicoll David C. A. , Dick Graeme 
Published: December 2007

Summary
Asphaltene deposition in the tubing and production facilities caused operational problems in the Ula reservoir. Laboratory and field studies were carried out to determine the point of asphaltene precipitation. Laboratory observations were made on the regimes of deposition as a function of decreasing pressure down to and below the bubblepoint of "live" crude oil samples. The tubing areas affected by deposition in the field corresponded to those identified in the laboratory and by subsequent pressure and temperature modeling of the wells. Large asphaltene deposits were also found in the production separators.
Studies of Water-Continuous Emulsions of Heavy Crude Oils Prepared by Alkali Treatment
Authors: Plegue T. H. , Frank S. G. , Fruman D. H. , Zakln J. L. 
Published: December 2007

Summary
Pumping of heavy crudes as concentrated oil-in-water (O/W) emulsions may be a feasible pipeline transport scheme for viscous crudes. Many crude oils can be emulsified by treatment with alkali without the addition of expensive surfactants. In experimental studies of seven crudes, stable emulsions could be formed with four by alkali treatment; two could not be emulsified; and one formed unstable emulsions. High shear viscosity, particle size, and stability measurements on 60% emulsions formed with various amounts of alkali are reported. High shear viscosities below 100 mPa·s [100 cp] at 25°C [77°F] indicate that concentrated emulsions of some crudes can be transported in pipelines at concentrations of 60% and higher.
Rheological Evaluation of Dense Suspensions: Simulation of a Fresh Cement Paste
Authors: Clark P. E. , Shaughnessy R. J. 
Published: December 2007

SummaryThe rheology of fresh cement pastes is a function of not only particle size, shape, and concentration, but also the cement setting reactions. This greatly complicates the analysis of data obtained in any rheological experiment. To separate the slurry contribution to the system rheology from the chemical reaction component, a slurry of marble-dust particles is used to represent a cement slurry.In this study, both tube-flow and concentric-cylinder [Rheometrics Pressure Rheometer™ (RPR)] rheometers are used to evaluate the rheological behavior of the dense suspensions. The apparent "slip" of the suspension makes correlation of the flow curves generated from the two viscometers difficult. The degree of slip in both viscometers becomes increasingly significant as the marble-dust concentration increases. The use of a grooved bob in the concentric-cylinder viscometer considerably reduces the amount of slip. Large annular gaps can also contribute to inconsistent results. An analysis of the data from both types of viscometers is presented.The Reiner-Riwlin equation, derived for a Bingham fluid, was used to approximate the flow curves generated with the concentric-cylinder viscometer. Marble-dust suspensions displayed antithixotropic behavior regardless of the water/solids ratio tested. These data are representative of an antithixotropic system that builds structure as the shear rate is increased. The duration of the tests affects the observed data only when sedimentation occurs during the test. When the denser marble-dust suspensions are tested, sedimentation occurs in the viscometer, producing an irregular shear thinning. Marble-dust suspensions generally provide a good model system for gaining an understanding of the rheological properties of fresh cement pastes.
Quartz Technology Allows for Wider Downhole Pressure Testing Range
Authors: Dennis J. R. , Zeller V. P. 
Published: December 2007

Summary
This paper presents a quartz-thickness shear-mode transducer for use in a borehole environment. The pressure sensor is a direct-conversion device that uses a noncylindrical shell to convert and to transmit forces to the quartz-crystal resonator. A brief conceptual description of the transducer is given. Laboratory and field examples illustrate the exceptional performance of the quartz-thickness shear-mode transducer.
Equilibrium Acid Fracturing: A New Fracture Acidizing Technique for Carbonate Formations
Authors: Tinker S. J. 
Published: December 2007

Summary
The equilibrium-acid-fracturing technique was developed to stimulate wells in the Wasson San Andres Denver Production Unit. This new treatment technique maximizes acid contact time with the fracture faces while allowing control of the created fracture dimensions. Maximum acid contact time is essential to create highly conductive etched pathways on the fracture faces of cool dolomite formations that react slowly with acid. Control of fracture dimensions is important in the San Andres Denver Unit because fractures tend to grow uncontained in at least one vertical direction and the oil column is bounded by permeable gas-bearing intervals above and permeable water-bearing intervals below.
With this technique, a fracture of desired dimensions is created by injection of acid at fracturing rates. The volume of acid required to create the desired fracture dimensions is determined by a 2D fracture-geometry program with design parameters determined from fracture field testing and laboratory testing. Injection is then continued at reduced rates that maintain equilibrium with the fluid leakoff rate from the created fracture faces. Maintaining equilibrium between injection and leakoff allows the created fracture to be held open without significant further fracture extension. Equilibrium is achieved in the field by maintaining the injection pressure below the fracture extension pressure but above the fracture closure pressure determined by fracture field testing.
This paper presents the background and theory of this technique along with design procedures, field examples, results, and conclusions. Results of the equilibrium-acid-fracture treatments and other acid stimulations performed in the Denver Unit are also compared.