bluuebunny/crossref_metadata_2025_split huggingface dataset:
Role of Silicate and Aluminate Ions in the Reaction of Sodium Hydroxide With Reservoir Minerals
Authors: Thornton S. D. 
Published: December 2007

SummaryA chemical model is presented for extrapolating laboratory data on mineral/alkali reactions to reservoir time scales. Minerals in sandstone and ions in caustic solution that control sodium hydroxide consumption during alkaline flooding were identified. This work may help operators predict when significant dissolution of the formation will occur and where precipitates will deposit.The dissolution of eight silicate minerals in caustic solution at 24 and 70°C [75 and 158°F] was determined. The minerals studied were quartz, two feldspars (microcline and albite), two micas (muscovite and biotite), and three clays (kaolinite, montmorillonite, and chlorite). The concentrations of sodium, silicate, aluminate, and hydroxide were measured periodically during bottle tests. Balanced chemical reactions are written for quartz, kaolinite, and phillipsite, and the corresponding equilibrium quotients are defined. A kinetic model is presented that includes rate constants, solid/liquid ratios, and equilibrium quotients to account for the effect of solution composition. The model was tested for kaolinite. The equilibrium quotient for kaolinite was found to be three times higher at 70°C [158°F] than at 24°C [75°F]. Dissolution-rate data were fitted successfully with the kinetic model.The reaction of Kern River reservoir sand with sodium hydroxide was studied to test the model. Consumption of sodium hydroxide occurred as predicted. However, caustic consumption was delayed in a slim tube packed with 99% quartz and 1% kaolinite, probably because of reduced nucleation of new minerals.
Pipeline-Life Assessment Based on a Leak-Growth Model
Authors: Hansen D. A. , Boah J. K. , Shelkh A. K. 
Published: December 2007

Summary
An empirical model is used to forecast the frequency of pipeline leaks and to assess pipeline failure rate. The model, which is based on a simple exponential-growth relationship, predicts the cumulative number of leaks, n, as a function of time: n = A exp(mt), where A and m are empirical constants. The model is applicable to essentially all carbon-steel pipelines exposed to serious corrosion attack, either internal or external. The model is useful in evaluating the technical and capital alternatives in pipeline design, operation, and maintenance.
Mechanisms of Residual Oil Displacement by Steam Injection
Authors: Stewart L. D. , Udell K. S. 
Published: December 2007

SummaryIn an attempt to isolate various thermal and hydrodynamic mechanisms, a model of one-dimensional (1D) steam displacement of residual oil has been developed. The quasisteady model considers capillary pressure gradients and gravity forces during the simultaneous flow of oil, water, and steam to be the dominant factors in oil-bank mobilization. It was shown that under most conditions, the Buckley-Leverett displacement velocity is significantly faster than the steam-condensation-front velocity. This feature dictates the use of the steam-condensation-front velocity as the characteristic velocity in the problem formulation. Semianalytical solutions of saturation and pressure distributions are presented.Experiments were conducted to examine steam displacement of volatile, partially volatile, and nonvolatile nonaqueous-phase liquids at a residual saturation of 2.5%. Complete displacement of all low-viscosity, partially volatile liquids was observed. Displacement of a high-viscosity, nonvolatile oil was not observed. These experiments and similar results from the literature were in reasonable agreement with the model. It is concluded that mass-transfer-limited evaporation of hydrocarbon components with significant vapor pressures is responsible for the observed low residual oil saturations (ROS’s) in the steam zone.
Foam Production During Steam Displacement of Aqueous Surfactants
Authors: Michaels Karen F. , Udell Kent S. 
Published: December 2007

SummaryThe formation and flow of foam in porous media under conditions characteristic of steam injection were examined through a series of one-dimensional (1D) displacement experiments. The steam-front propagation velocity and temperature field ahead of and behind the condensation front were not significantly different for steam injection into partially saturated or dry media compared with injection into a water-saturated medium. Significant differences in measured parameters were observed during steam displacement of a 1 wt% surfactant solution. The steam-phase mobility decreased upstream of the condensation front by factors of 5.7 and 14 under conditions where noncondensable gases were not present and present as an initial gas saturation, respectively. These results clearly indicate that foam is produced during steam displacement of a surfactant solution without the presence of a noncondensable gas. Furthermore, noncondensable gas in the porous matrix was immobilized by the surfactant and aided in the stabilization of the foam in the steam zone.
A Regression Technique With Dynamic Parameter Selection for Phase-Behavior Matching
Authors: Agarwal Rajeev K. , Li Yau-Kun , Nghlem Long 
Published: December 2007

Summary
The major problem in phase-behavior matching with a cubic equation of state (EOS) is the selection of regression parameters. Many parameters can be selected as the best set of parameters; therefore, a dynamic parameter-solution scheme is desired to avoid tedious and time-consuming trial-and-error regression runs. This paper proposes a regression technique in which the most significant parameters are selected from a large set of parameters during the regression process. This technique reduces the regression effort considerably and alleviates the problem associated with a priori selection of regression parameters. The technique's success is demonstrated by matching experimental data for a light oil and a gas condensate.
Development of Reservoir Descriptions To Aid in Design of EOR Projects
Authors: Chopra A. K. , Stein M. H. , Ader J. C. 
Published: December 2007

Summary
A technique was developed to obtain reservoir descriptions to aid in the design of EOR projects. This technique incorporates the reservoir performance during primary and secondary processes and the geological, petrophysical, and pressure-transient data. The application of this technique is illustrated for a San Andres formation reservoir.
Laboratory Study of Foaming Surfactant for CO2 Mobility Control
Authors: Di Julio S. S. , Emanuel A. S. 
Published: December 2007

Summary
The effectiveness of foam as a mobility-control agent has been tested by an immiscible CO2 coreflood displacement of a California heavy oil (14°API [0.97 g/cm3]). Foam was produced by simultaneous injection of 0.5 wt% surfactant solution and CO2. Foam injection recovered an incremental 33.6% of original oil in place (OOIP) by reducing CO2 mobility and diverting CO2.
The Effects of Size, Shape, and Orientation of an Impermeable Region on Transient Pressure Testing
Authors: Britto Paulo R. , Grader Abraham S. 
Published: December 2007

SummaryA practical consideration of the effects of the shape, size, and orientation of an impermeable reservoir region on transient pressure testing is presented. The constant-rate production well is external to the impermeable region. Impermeable regions may be in the form of sealing fractures of finite length that have little volume associated with them and that are only a local restriction to fluid flow. These regions may also be shale lenses or reduced-permeability regions that, in addition to being a restriction to flow, occupy a significant reservoir volume. This paper considers a single impermeable region with various sizes, shapes, and orientations with respect to the active source well.The transient pressure response of the constant-rate well is generated by replacing the impermeable boundaries by a set of line sources and then applying the method of superposition. This method can be extended to include pressure responses of interference wells. The method is validated by matching the pressure responses of simple cases like a linear no-flow boundary and an internal circular no-flow boundary.The key issue of this paper is the detectability of large-scale impermeable reservoir regions by transient pressure analysis. The presence of an impermeable region causes the pressure response to deviate from the homogeneous line-source response. This pressure deviation is the indication that the reservoir is heterogeneous. Four major parameters affect the pressure response of the active source well in the presence of an impermeable region: (1) the shortest distance between the well and the impermeable region, (2) the size of the region, (3) the shape of the region, and (4) the orientation of the region. This paper presents combinations of these four parameters that significantly affect the transient pressure response, as well as some criteria for deciding what impermeable regions may be uniquely detected.
A Comparison Between the Pressure-Lag Model and the Rate-Type Model for the Prediction of Reservoir Compaction and Surface Subsidence
Authors: Smits R. M. M. , de Waal J. A. 
Published: December 2007

Summary
A theoretical study has been carried out to investigate whether the nonlinear compaction behavior of sandstone reservoirs, which has been reported for most well-documented field cases, can be explained by pressure lags in interbedding and/or neighboring low-permeability (shale) layers. On the basis of the results obtained, it is concluded that pressure-lag effects in normally encountered production scenarios cannot account for these nonlinearities, even under worst-case conditions. Therefore, the nonlinear field-compaction behavior must be caused by rate effects in the sandstone reservoir rock itself. This is supported by the fact that a rate-type compaction model recently introduced does indeed give a good description of the observed field behavior.
Advances in Borehole Seismic Fracture Diagnostics
Authors: Thorne B. J. , Morris H. E. 
Published: December 2007

Summary
Recent redesign of the hardware, software, and data-reduction techniques associated with a triaxial borehole seismic system (BSS) have made possible better estimates of hydraulic fracture geometry. The redesigned triaxial system now incorporates three geophones per axis and provides 30 times the downhole gain of the replaced system, resulting in improved signal-to-noise ratios. This stronger signal, with an increased digitization rate for each of the six simultaneously digitized channels from two borehole seismic tools, has made possible the acquisition and processing of data that previously were inaccessible. The new electronics makes use of a null system and an improved calibration system that includes a synthetic event generator to produce sinusoidal signals of specified amplitude, frequency, and phase. These make readjustments to maintain system balance while the tool is in place downhole. A maximum likelihood event location scheme, incorporating an algorithm based on the use of directional statistics, is used to compute the location of microseisms and error estimates for these locations. Based on the ability to locate perforation shots, a 25-ft [7.6-m] uncertainty in the location of individual microseisms is the estimated accuracy of the redesigned system. This resulted in a fairly high level of confidence in the determination of the azimuth of the Nov. 1, 1986, hydraulic fracture in the fluvial zone at DOE's Multiwell Experiment (MWX) site.
Dynamic Etching Tests Aid Fracture-Acidizing Treatment Design
Authors: Anderson M. S. , Fredrickson S. E. 
Published: December 2007

Summary
Satisfactory stimulation of oil- and gas-bearing formations by fracture acidizing depends on development of adequate fracture conductivity in the hydraulically induced fracture. The created fracture conductivity is a result of the reaction of the injected acid with the fracture face. This paper describes a laboratory core-testing procedure to evaluate the feasibility of an acid treatment and to allow optimization of several treatment parameters. Applications to treatment design for formations that typically are difficult to stimulate by fracture acidizing are given.
Author's Reply to Further Discussion of Application of Oil Muds
Authors: Bloemendal J. W. 
Published: December 2007

Abstract
I thank Benning for his extensive comments and support of most of my remarks.
In my 38 years as a mud engineer, both in research and in the field, I have seen many magic applications rise, shine, and sink. Much frustration and waste of money is prevented if petroleum engineers are more critical and distinguish between sales talk and science, between theory and practice.
Undoubtedly, oil-based muds (OBM's) outperform water-based muds (WBM's) in specific problem areas, but I believe they have been oversold and applied where no hard facts justified their use. In particular, the claimed higher rate of penetration has never been proved scientifically. In drilling practice, too many factors play a role to justify the conclusions without studies supported by measurements in the laboratory. With a relaxed WL CLS mud of the same weight and bottom-cleaning performance, with more weight on bit (as read on the weight indicator) to correct for the friction loss, and with all other factors the same, I expect little noticeable difference between OBM's and WBM's.
Modeling of the Stability of Highly Inclined Boreholes in Anisotropic Rock Formations
Authors: Aadnoy Bernt S. 
Published: December 2007

Summary
Simulators have been developed to study the fracture and collapse behavior of boreholes. To take into account the directional properties of real rocks, an anisotropic stress model is used. The model takes into account anisotropic elastic properties, directional shear, and directional tensile strengths. The orientation of the borehole, the in-situ stresses, and the bedding plane can all be arbitrarily related to each other to model actual field situations. This paper presents some of the results of the model. It is shown that neglecting the anisotropic effects introduces an error. Also, studying the anisotropic model yields further insight into the behavior of the borehole.
Concentration Measurements Above an Underwater Release of Natural Gas
Authors: Løes M. , Fanneløp T. K. 
Published: December 2007

Summary
Underwater gas releases resulting from blowouts, pipeline or riser breaks, etc., represent a fire hazard for structures and craft near the surfacing zone. The hydrodynamics of the underwater bubble plume has been the subject of several recent investigations, but no method or data that are useful in predicting the gas concentration above the surfacing zone are known to exist. This paper presents measurements from a field experiment using methane flow rates up to 1.3 normal m3/s [46 scf/sec] at a depth of 50 m [164 ft]. In addition to the continuous concentration measurements from four sensors in the surfacing zone (50 cm [20 in.] above the water surface), certain plume parameters (e.g., plume rise time in air and water and plume center wandering and offset) were either measured or deduced from video recordings. The experiments were performed under ideal weather conditions and the data obtained were not influenced by such extraneous environmental factors as wind, waves, currents, or stratification. For comparison with the data, a simple momentum theory was developed for the zone of formation of the light-gas plume. The agreement with the averaged concentration data is very good over the range of flow rates investigated.
Chemical Shrinkage Properties of Oilfield Cements
Authors: Chenevert M. E. , Shrestha B. K. 
Published: December 2007

Summary
Chemical shrinkage was measured at elevated temperatures and pressures for 29 different cements with modified PVT equipment. Results showed that a "dilution" effect exists; i.e., the cements that had the highest yield had the lowest chemical shrinkage. For the 29 tests, the maximum chemical shrinkage measured was 4.6% and the minimum was 1.6%. Tube column tests showed that chemical shrinkage helped to reduce hydrostatic pressures.
Uses and Limitations of Drillstring Tension and Torque Models for Monitoring Hole Conditions
Authors: Brett J. F. , Beckett A. D. , Holt C. A. , Smith D. L. 
Published: December 2007

Summary
This paper presents the results of the application of a tension/torque model to directional wells drilled worldwide. The final inclination of the wells ranged from 25 to 70°, and the tension/torque model was effectively used in these cases to aid in planning the directional program before spudding, to monitor the wells during drilling, and to analyze particular drilling problems after completion. The first set of examples represents the situations to which the tension/torque model can be routinely applied and shows that the model can effectively aid the well planner in selecting the best well path, drillstring designs, casing program, and mud system before spudding. A second set of examples shows how real-time monitoring of drilling conditions can be combined with the model to develop a baseline so that deviations from expected behavior can be analyzed and explained. Appropriate action can then be taken to remedy problems before they become serious. A final set of examples shows how a tension/torque model can be effectively used to determine the actual cause of a particular drilling problem after a well is completed. Experience gained from postanalysis of problems can be used to improve later operations. This paper also compares field data with model predictions for a wide range of different inclinations.
Swelling of Oil-Based Drilling Fluids Resulting From Dissolved Gas
Authors: O'Bryan Patrick L. , Bourgoyne Adam T. 
Published: December 2007

SUMMARY
The method presented in this paper uses an experimentally calibrated equation-of-state (EOS) model to estimate the swelling of oil-based drilling fluids caused by dissolved methane. With this method, the pit gain associated with a given kick size can be determined. The calculation method was verified by experiments conducted in a 6, 000-ft [1828.8-m] test well. Example calculations are also presented.
Directional Acoustic Surveying Instrument
Authors: Treherne D. M. , Harper P. G. , Su D. 
Published: December 2007

Summary
A new type of acoustic detector capable of determining the direction of a noise source was developed. Under granite transmission at a depth of 600 m [1,970 ft] and ranges up to 200 m [655 ft], directional accuracies of 1 to 2° were achieved. Detectable sources included quasicontinuous (e.g., drill-bit) noise and pulses (e.g., explosive or sparker tool). The sensing element is a symmetric resonator whose flexural modes are readily excited by an external acoustic source. The physical principle is that the phase plane of a strong acoustic spectral component fixes the nodal directions of the resonant flexural vibrational mode, thus establishing the propagation direction in relation to the modal symmetry. The resonator is encapsulated in oil to damp the vibrations and to retain and communicate the acoustic signal. (The vibrational modal pattern is detected with strain gauges and processed to provide directionality.) This paper presents (1) vibrational response theory; (2) construction details; and (3) analysis of field data leading to directionality.
Flow of Non-Newtonian Fluids Through Eccentric Annuli
Authors: Luo Yuejin , Peden J. M. 
Published: December 2007

Summary
The laminar eccentric annular flow of non-Newtonian fluids is analyzed with a new method where an eccentric annulus is represented by an infinite number of concentric annuli with variable outer radii. The analytical solutions for the shear stress, shear rate, velocity, and volumetric flow rate/pressure gradient are obtained for both power-law and Bingham-plastic fluids. This method is shown to provide more accurate approximations for various profiles and good predictions of the volumetric flow rate/pressure gradient in eccentric annular flow. In addition, turbulent eccentric annular flow is discussed.
Drag Bit Wear Model
Authors: Slnor A. , Warren T. M. 
Published: December 2007

Summary
A performance model for polycrystalline-diamond-compact (PDC) bits was modified to include the wear prediction of individual cutters. Wear predictions are based on the geometry of each cutter, the rock type, the forces acting on the cutter, cutter velocity, and cutter temperature. The results of predicted and actual cutter wear for different 8½-in. [21.6-cm] field-worn PDC bit designs are shown. The worn geometry of each cutter was measured and compared with the model's prediction.
Laboratory performance tests were also conducted with similar bit designs to quantify the effect of bit imbalance. Reduced rate of penetration (ROP), drilling an overgauge hole, and increased cutter wear and breakage can result from bit imbalance.
Computation and Interpretation off Miscible Displacement Performance in Heterogeneous Porous Media
Authors: Corrêa A. C. , Pande K. K. , Ramey H. J. , Brigham W. E. 
Published: December 2007

Summary
Computation of miscible displacement performance requires an estimate of the amount of mixing in the reservoir. Dispersion coefficients measured from displacements in laboratory cores are often used to compute reservoir performance. This paper considers interpretation of effluent flowing concentration data obtained from heterogeneous cores by use of the Coats-Smith, porous-sphere, and transverse-matrix-diffusion heterogeneous models. Analytical solutions to the three heterogeneous models are presented in Laplace space. Approximate solutions for short- and long-time effluent flowing concentrations, developed from simplification of the Laplace transformation solution, are used to develop practical methods of interpreting effluent concentration data to determine model parameters. Criteria for design of laboratory experiments based on these results are suggested.
Composition Paths in Four-Component Systems: Effect of Dissolved Methane on 1D C02 Flood Performance
Authors: Monroe W. Wesley , Silva Matthew K. , Larsen L. L. , Orr Franklin M. 
Published: December 2007

Summary
New measurements of phase compositions and densities are reported for a quaternary system containing CO2, methane, butane, and decane and related ternary systems at 160°F and 1, 250 psia [71°C and 8620 kPa]. Measured values of phase compositions and vapor densities agreed well with values calculated with the Peng-Robinson equation of state (PREOS), though calculated liquid densities were less accurate. Composition paths for two-phase flow of four-component mixtures were calculated with the method of characteristics and the equation-of-state (EOS) representation of the phase behavior. Analysis of resulting paths indicates why displacement efficiency in ID CO2 floods is insensitive to the addition of dissolved methane to the oil displaced. Methane in the oil partitions so strongly into the more mobile vapor phase that a methane-rich bank forms at the leading edge of the transition zone. The displacing CO2 then encounters hydrocarbon mixtures without methane. Analysis indicates that high displacement efficiency is possible even when two-phase flow occurs throughout the displacement and that high recovery is possible even when a live oil is displaced below its bub-blepoint pressure (BP), if the pressure is above the minimum miscibility pressure (MMP) for the same oil with all methane removed.
A Cross-Sectional Simulation of West Heidelberg In-Situ Combustion Project
Authors: Kumar Mridul 
Published: December 2007

Summary
In-situ combustion (ISC) in a deep, thin, dipping reservoir was simulated to delineate major production mechanisms and to improve reservoir management. Results show that air injection is preferable over flue-gas injection because pressure maintenance accounts for less than half of the cumulative oil production. Water injection following air breakthrough resulted in little incremental recovery. Recovery can be maximized by placing the production well near the lower edge.