bluuebunny/crossref_metadata_2025_split huggingface dataset:
Laboratory Development and Field Application of a Novel Water-Based Drill-In Fluid for Geopressured Horizontal Wells
Authors: Dobson J. W. , Harrison J. C. , Hale A. H. , Lau H. C. , Bernardi L. A. , Kielty J. M. , Albrecht M. S. , Bruner S. D. 
Published: December 2007

Summary
Research has identified a novel water-based drill-in fluid for drilling and completing geopressured horizontal wells. This fluid has a unique combination of properties which make it especially suitable for geopressured applications. They include the use of calcium and/or zinc bromide as a base brine, minimal concentration of calcium carbonate as bridging material, low plastic viscosity, tight fluid loss control, good filter-cake properties, and excellent return permeability. This drill-in fluid has been used successfully to drill a 1,200-ft production interval, 4.75-in. diameter wellbore in the Gulf of Mexico with a system weight of 13.2 lbm/gal, bottomhole temperature of 185°F, and a 1,400 to 1,700 psi overbalance. The system functioned very well in both the drilling and the completion operations. Fluid rheology was easily maintainable and the hole conditions were excellent without torque or drag problems. Initial production data suggest that the well is producing at expected rates with low drawdown pressure.
Water Injection Profile Modification in a Layered Reservoir With Polymer Treatment
Authors: El-Hadidi S. M. , Falade G. K. , Dabbouk C. , Al-Ansari F. 
Published: December 2007

SummaryThe main focus of this paper is the applications of polymer treatment in controlling injectivity and the improvement of the nearwellbore injection profiles.Reservoir high-permeability zones causing distortions of water injection profiles at the wellbore, and the possible existence of layer barriers, were identified with conventional investigation tools such as openhole logs, production logging tools, formation, and microscanners.A polymer screening procedure was put in place so that appropriate polymer formulations that can reduce fluid mobility in the high-permeability zones at the near-wellbore region can be identified. The use of these polymer formulations facilitated the improvement of wellbore injectivity profiles.The field performance of the polymer treatment program was ascertained by the use of a monitoring program that combined the application of the production logging tools and well-test analyses.
A Note on IMPES and Some IMPES-Based Simulation Models
Authors: Coats K. H. 
Published: December 2007

SummaryThe generalized IMPES method applies to simulation models involving any number of conservation equations. The IMPES pressure equation is a linear combination of the linearized conservation equations. This article shows the generality, simplicity, uniqueness, and derivational brevity of that equation. The associated IMPES reduction vector leads directly to the value of total compressibility in a multiphase gridblock. That compressibility in turn gives several error checks on black oil pressure/volume/temperature (PVT) data.Three IMPES-type compositional models are compared and found to be very similar, with moderate differences in efficiencies and generality. An example problem serves two comparative purposes related to IMPES model efficiency.
Frontier Geothermal Drilling Operations Succeed at 500°C BHST
Authors: Saito Seiji , Sakuma Sumio 
Published: December 2007

Summary
The Japanese government-funded geothermal exploration Well WD-1A reached 3729 m at total depth, where the bottomhole static temperature is more than 500°C. A trajectory correction run was carried out with a positive displacement motor and measurement while drilling tool where the formation temperature is greater than 350°C. The combination of large surface mud containers and sufficient mud cooling equipment were used to cool return mud from the well. A top drive system was used to cool the bottomhole assembly while running each drillpipe stand in the hole. A borehole dynamic temperature experiment and drill bit tests were carried out in this well.
Generalized 3D Analytical Model for Transient Flow in Compartmentalized Reservoirs
Authors: Rahman N. M. A. , Ambastha A. K. 
Published: December 2007

SummaryA new generalized transient-flow model for a three-dimensional (3D) compartmentalized system with n compartments has been developed analytically. Each compartment may have distinct rock and fluid properties and may produce through a number of partially penetrating wells. A partially communicating fault or barrier causing poor hydraulic communication between a pair of adjoining compartments is modeled as a thin skin at the interface. Production rates and conditions at the extreme boundaries are considered to be time variant. The solution was also validated by examining a few limiting cases. An example problem with stacked channel realization was studied. A simple method for detecting the poorly drained compartments from the extended drawdown data was developed. This has also lead to an estimation of hydrocarbon-pore volume in each compartment.
Geostatistical Analysis of Permeability Data and Modeling of Fluid-Flow Effects in Carbonate Outcrops
Authors: Jennings J. W. , Ruppel S. C. , Ward W. B. 
Published: December 2007

Summary
Permeability data from Permian dolomitized shallow-water platform carbonate outcrops in west Texas and New Mexico exhibit two to five orders of magnitude variability, most of which occurs within distances of a few feet [1 to 2 m] within single rock-fabric units. A variety of longer-range features are also observed, including vertical interbed average-permeability contrasts, 140- to 180-ft [42- to 54-m] lateral periodicities, and up to 2,700-ft [810-m] lateral trends. The short-range heterogeneities can be modeled with K-Bessel semivariograms having asymptotic power-law behavior at the origin. The periodicities can be modeled with "hole-effect" J-Bessel semivariograms.
Stochastic two-dimensional areal and vertical cross-section models explore the effects of these heterogeneities. Fluid-flow simulations demonstrate that some long-range features control overall flow behavior even when short-range variability composes most of the variance. The short-range heterogeneities produce local smearing of displacement fronts.
Production-Induced Compaction of a Sandstone Reservoir: The Strong Influence of Stress Path
Authors: Hettema M. H. H. , Schutjens P. M. T. M. , Verboom B. J. M. , Gussinklo H. J. 
Published: December 2007

Summary
The decrease of pore pressure during hydrocarbon production (depletion) leads to compaction of the reservoir, which in turn changes the stresses acting on the reservoir. The prediction of reservoir compaction and its consequences is usually based on laboratory experiments performed under uniaxial strain conditions, i.e., allowing no lateral strain during depletion. Field data of the Groningen gas field (The Netherlands) indicate that the stress development of the field deviates significantly from the stress path under uniaxial strain conditions. Laboratory experiments show that the applied stress path has a strong influence on the depletion-induced compaction behavior. We discuss the consequences of these results for the field compaction behavior by considering the responsible deformation mechanisms active in reservoir and experiment. The new Groningen field data, in combination with our experimental results, provide an explanation for the difference between the prediction of compaction and subsidence based on uniaxial experiments and the measurement of compaction and subsidence in the Groningen field. With the use of the new stress path, the predicted and measured compaction and subsidence are in agreement.
A Relation Between Gamma Radiation and Permeability, Denver-Julesburg Basin
Authors: Rabe C.L. 
Published: December 2007

Introduction
The Muddy and Dakota sands, more commonly known as the "D" and "J" sands, respectively, of the Denver-Julesburg Basin are correlative over a large area. It is reasonable to believe, therefore, that depositional environment throughout the Basin was comparable. Local variations in sand development do occur, however, and productivity is often governed by permeability as well as structural position. Experience indicates permeability is commonly a function of cementing material. While cases of siliceous or calcareous cementing have been observed, the bonding material is, for the most part, clay. Under the latter circumstance, clay should bear some relation to permeability. Similarly, gamma radiation should bear some relation to the amount of clay. This study was undertaken to determine if a cross relation exists between gamma radiation and permeability.

Results of Investigation
A qualitative relation does exist between gamma radiation and permeability for clay-bonded Muddy and Dakota sands of the Denver-Julesburg Basin. This is illustrated graphically by Fig. 1, which shows corrected gamma ray deflection vs permeability for five wells over an area approximately 50 miles long and 8 miles wide. The "corrected" gamma ray deflection cannot be read directly from the gamma ray survey in all cases. It became apparent early in the investigation that methods would have to be developed for converting all gamma ray surveys to a common deflection scale and to correct for thin bed effects.

Common Scale Deflection
Because all logs are not recorded in the same calibration units or at the same sensitivity, it was felt they could be most readily converted to a common scale by measurement of deflection in inches from zero. Initially, four wells in the Jacinto field of Nebraska were carefully correlated, and selected intervals were planimetered to obtain average deflections.
Fully Coupled Analysis of Well Responses in Stress-Sensitive Reservoirs
Authors: Chin L. Y. , Raghavan R. , Thomas L. K. 
Published: December 2007

Summary
A fully coupled geomechanics and single-phase, fluid-flow model is developed to evaluate the combined effects of stress, fluid flow, and reservoir property changes on well responses in stresssensitive reservoirs. In particular, we pay attention to the interpretation of pressure buildup tests and to changes in the production characteristics of wells. In general, for weak hydrocarbon reservoirs that exhibit nonlinear, elastic and plastic constitutive behaviors, and stress-dependent properties such as permeability and porosity, the physical effect contributed from geomechanics may not be ignored in well test analysis. The coupled interaction between geomechanics and reservoir fluid production markedly affects the stress state and reservoir properties. Because we are using a coupled, numerical model, we evaluate the consequences of using simplified relationships (e.g., permeability as a function of pressure). Numerical analyses are performed to quantitatively assess the impact of reservoir stress sensitivity on practical well test problems. The key variables investigated in the study, that are important in evaluating stress-sensitive reservoirs, include permeability, porosity, and constitutive behaviors of reservoir rock including hysteresis and loading conditions. The development of high-stress regions around wellbores and its consequences on well performance are considered. The numerical results from the study indicate that for analyzing highly stress-sensitive reservoirs, a fully coupled geomechanics and fluid-flow modeling approach is necessary and the developed model employed in this study provides such a tool.
The Effect of a Short Term Shut-In on a Subsequent Pressure Build-Up Test on an Oil Well
Authors: Nisle Robert G. 
Published: December 2007

Abstract
In conducting a pressure build-up test on an oil well, it is often necessary to shut-in the well for a short time prior to initiation of the test. The effect of such a short term shut-in on the resulting pressure build-up curve is derived. The derivation is based on the Kelvin point-source solution and is a straight forward extension of the fundamental theory.
The magnitude of the effect is evaluated and illustrated by an example. It is shown that if the production subsequent to the short term shut-in is at least 10 times the duration of the shut-in, the effect will be less than 10 per cent.

Introduction
It often happens that before a pressure build-up test can be made an additional valve must be mounted on the wellhead, or on arrival at the well, it might be learned that the well had been shut-in several hours the previous day because of a shortage of tankage. In such cases the question is "How will such an interruption of production affect the results of a pressure buildup test?" This work explains how to take account of such a short term shut-in in order that the test can proceed without further delay.
The solution presented here makes use of the Kelvin point-source solution used by Horner in his treatment of the pressure build-up in wells. Use is also made of the super-position theorem.

Mathematical Derivation
The well is assumed to have been in production at a constant rate for a relatively long time (several days or more). It is then shut-in for a short time, after which it is again placed in production at the previous constant rate. It continues to produce at this rate until shut-in for a pressure build-up test.
The Kelvin point-source solution is expressed by Eq. 1.
Computational Fluid Dynamics (CFD) Study of Bubble Carry-Under in Gas-Liquid Cylindrical Cyclone Separators
Authors: Erdal F. M. , Shirazi S. A. , Mantilla I. , Shoham O. 
Published: December 2007

Summary
The gas-liquid cylindrical cyclone (GLCC©) separator is an attractive compact separator alternative to the conventional vessel-type separator. Thus, it is important to develop predictive tools for design and to be able to improve the technology of the GLCC. Previous studies on the GLCC have focused on mechanistic models capable of predicting the operational envelope for liquid carryover and on the understanding of the flow field in the GLCC. The main objective of this work was to investigate the behavior of small gas bubbles in the lower part of the GLCC, below the inlet, and the related gas carry-under phenomena. This investigation was performed by flow visualization and by using a commercially available computational fluid dynamics (CFD) code. Simulations of single-phase and two-phase flows were carried out and bubble trajectories were obtained in an axisymmetric geometry that represents the GLCC configuration. Bubble trajectory analysis was used to quantify the effects of the important parameters on bubble carry-under. These include bubble size, ratio of the GLCC length below the inlet to diameter, viscosity, Reynolds number, and inlet tangential velocity.
Kinetics of the Primary Reaction of HF on Alumino-Silicates
Authors: Gdanski R. D. 
Published: December 2007

SummaryThe standard description of HF acidizing chemistry clearly demonstrates a primary and secondary reaction of HF with alumino-silicates.1–6 Field experience has taught our industry that possible precipitation during the secondary reaction can adversely affect treatment success,7,8 especially in formations with high K-feldspar content9 or temperatures above 300°F. Recent work has also been reported on the existence of a third, or tertiary reaction of HF with alumino-silicates.10In this paper determination of the rate law and kinetics for the primary reaction of HF on sand, clay, and feldspar over a broad temperature range is reported. The rate law for the primary reaction of HF with sand had no HCl dependence and was second order in HF concentration. The rate law for the primary reaction of HF with clay and feldspar was assumed to also have no HCl dependence and was adequately described by a first order in HF concentration. In addition, a mass transfer equation for reactive fluids flowing through porous sandstone media is proposed. These findings were made possible by recently applied experimental techniques including 19F nuclear magnetic resonance (NMR) spectroscopy,10 fractional pore-volume flow experiments,11 and an accurate knowledge of the HF stoichiometry.12 Laboratory findings have been verified through detailed analyses of flowback samples from field treatments.13
Correlation of Emulsion Stability With Phase Behavior in Surfactant Systems for Tertiary Oil Recovery
Authors: Vinatieri James E. 
Published: December 2007

Abstract
This paper describes a study of the emulsions which could occur during a pilot surfactant flood, such as that conducted by Phillips Petroleum Co. in the North Burbank Unit, Osage County, OK. The phase behavior of this surfactant system can be characterized by three types of microemulsions, with the transition from one type to another being a function of the salinity. The rate at which emulsions coalesce was seen to correlate directly with the type of microemulsion.
Coalescence was slow for macroemulsions at low salinities, rapid at intermediate salinities (where the final state was a three-phase system), and varied from slow to rapid at salinities above the three-phase region. Knowledge of the correlation between phase behavior and emulsion stability can be useful in treating macroemulsions produced during a surfactant flood.
Formulation of a General Multiphase, Multicomponent Chemical Flood Model
Authors: Fleming Paul D. , Thomas Charles P. , Winter William K. 
Published: December 2007

Abstract
A general multiphase, multicomponent chemical flood model has been formulated. The set of mass conservation laws for each component in an isothermal system is closed by assuming local thermodynamic (phase) equilibrium, Darcy's law for multiphase flow through porous media, and Fick's law of diffusion. For the special case of binary, two-phase flow of nonmixing incompressible fluids, the equations reduce to those of Buckley and Leverett. The Buckley-Leverett equations also may be obtained for significant fractions of both components in the phases if the two phases are sufficiently incompressible. To illustrate the usefulness of the approach, ã simple chemical flood model for a ternary, two-phase system is obtained which can be applied to surfactant flooding, polymer flooding, caustic flooding, etc.
Subsurface Sealing of Tubing Thread Leaks
Authors: True Martin E. , O&apos;Reilly W.M. 
Published: December 2007

Abstract
A technique, equipment, and a compound have been developed and field tested for sealing tubing joint thread leaks without removing the tubing from the well. This eliminates the necessity of killing the well with possible damage to the producing formation, which could result if it were exposed to drilling mud. A thread sealing compound, developed and tested in the laboratory, is introduced into the tubing and squeezed into the joint to eliminate the leak. A high percentage of successful field applications have effected an appreciable cost reduction in repairing leaking tubing strings in East Texas and in the Louisiana Gulf Coast area.

Introduction
In producing oil and gas wells the industry has been plagued with a never ending problem of tubing connection leakage. This situation is becoming increasingly more significant as more gas wells are placed on production and as higher pressures are encountered at greater depths of current drilling.
Substantial progress has been made in minimizing thread leaks by careful handling and cleaning of joints and by the use of improved sealing compounds in combination with controlled makeup. But even with the use of the best known methods and sealing materials during initial makeup, occasional leaks through tubing joint threads appear inevitable. In some instances, tubing joints in high-pressure gas wells have been found to leak gas at relatively less pressure than that at which the tubing had been tested satisfactorily using liquid.
Many expedients have been employed to prevent the physical replacement of tubing when leaks have developed. Perhaps the most commonly used is the sodium silicate treatment in which the solution is lubricated into the tubing to form a crystalline plug in the leak. Generally, any benefit realized is of a temporary nature.
In addition to field studies on handling and makeup of tubing, extensive laboratory work has been undertaken on the development and testing of thread dopes. Also, substantial effort has been devoted to testing tubing joints using high-pressure gas as a pressure medium. The results of this work have emphasized that tubing joints are susceptible to occasional leaks, especially when subjected to relatively high differential pressures.
To cope with the problem of leaking connections, an extensive investigation was undertaken to devise means of sealing leaks without removing the tubing from the well and without reducing the inside diameter of the tubing. The purpose of this paper is to present a technique, together with the associated equipment and compound, which have been developed for effecting a seal of leaking tubing in place.
Reverse Combustion Instabilities in Tar Sands and Coal
Authors: Gunn Robert D. , Krantz William B. 
Published: December 2007

Abstract
A linear stability analysis shows that reverse combustion in coal and tar sands is only conditionally stable for mobility ratios less than one. However, high air-flow rates and gas generation at the combustion front can be stabilizing influences. For unstable operation, an estimate of the size of the reverse combustion channel may be obtained from the curve for the most highly amplified wave length. This provides a method for calculating the air flux, combustion front velocity, and rate of progress of the burn front.
Recently the U.S. DOE Laramie Energy Technology Center (LETC) and Sandia Laboratories obtained experimental data about reverse combustion from a field test of in-situ coal gasification at Hanna, WY. These data show that 9.7 days were required for the development of a reverse combustion path 68 to 70 ft in length. The stability theory developed in this work predicts a length of 64 ft for this same 9.7-day period. In addition to quantitative predictions, stability theory provides an explanation of certain puzzling qualitative observations concerning reverse combustion.