bluuebunny/crossref_metadata_2025_split huggingface dataset:
Flow of Non-Newtonian Fluid in Porous Media
Authors: Abou-Kassem J. H. , Farouq Ali S. M. 
Published: December 2007

ABSTRACT
A mathematical description of non-Newtonian fluids, in particular, emulsions, is of special importance now that most of the enhanced oil recovery methods are being modeled in increasing detail. Only recently a few characteristics of emulsion flow have been incorporated in some of the simulators. Nearly all enhanced oil recovery processes involve emulsion formation and flow in some form or other. Representation of such flow in mathematical models is still inadequate.
This paper investigates the rheology of emulsions, their formation in porous media, and subsequent flow, from a mathematical standpoint. A critical evaluation of several models describing the flow of pseudoplastic fluids in porous media is presented. The models are expressed in a unified form that makes it possible to detect differences between the various models. The assumptions underlying the various models are discussed in detail. Furthermore, the paper gives a summary of the rheology and in situ formation of emulsions, and the role of a variety of other factors responsible for emulsification in porous media.
The paper concludes with suggestions for incorporating emulsion flow in reservoir simulators. Extension to non-isothermal conditions is also discussed.
Simulation of Laboratory In-Situ Combustion Data and Effect of Process Variations
Authors: Kumar M. 
Published: December 2007

ABSTRACT
A fully implicit thermal simulator was validated by history matching laboratory combustion tube data. The validated simulator was used to identify important parameters that influence the predicted results and to study the effects of process variations. Measured cracking reaction parameters were used to minimize the number of adjustable parameters in history matching.
Results indicate that the simulator can history match the laboratory data when the relative permeabilities are modified. Matched experimental parameters include cumulative oil and water production histories, location of combustion front as a function of time, and peak temperatures along the tube. The simulation results were insensitive to the kinetics of combustion, grid size, sand thermal conductivity, and equilibrium coefficient of the heavy oil pseudocomponent. The results, however, were sensitive to relative permeability, capillary pressure near the irreducible water saturation, and equilibrium coefficient of the light oil component.
Predicted trends for oxygen injection, wet combustion, and variation in injection rates agree very well with published experimental results. Injection of oxygen instead of air (for nearly the same combustion front velocity) caused a significant increase in the fuel consumption and peak temperatures. Wet combustion generally caused a decrease in the fuel consumption and the average peak temperature, and an increase in the combustion front advance and production rates. The velocity of the combustion front was proportional to the air flux at the combustion front, except at very high injection rates. This implies that at field-like injection rates, the combustion process is air (oxygen) flow rate controlled.
Borehole Instability: Case Histories, Rock Mechanics Approach, and Results
Authors: Maury V. M. , Sauzay J-M. 
Published: December 2007

ABSTRACT
In order to find a solution or at least to minimize the consequences of borehole instability, two complementary approaches of the problem have been used:
– Case history analysis: identify from the different types of drilling problems those related to a poor borehole behavior, characterize the conditions for occurrence and main consequences (breakouts, cavings, reaming, torque) in agreement with a proper geomechanical behavior of the borehole. Several independent, or interconnected factors are controlling the borehole stability: high or low, isotropic or anisotropic horizontal stresses, particular rock rheological behavior, excessive wall stresses induced by fast tripping, pressure and temperature gradient around the borehole. – A comprehensive theoretical analysis providing a stress distribution around the borehole, avoiding irrelevant material behavior, and concentrating on the different loadings which may already explain most of the time-delayed instabilities (thermal and seepage stresses). Some major and unusual conclusions will be outlined: several rupture modes, maximum stress concentration inside the wall.
Two documented case histories are described. They allow to be rather optimistic regarding the efficiency of this mixed approach of the problem in providing less empirical solutions to drilling problems.
Guidelines for Stable Foam Drilling Through Permafrost
Authors: Fraser I. M. , Moore R. H. 
Published: December 2007

ABSTRACT
Stable foam was used successfully on ten wells in the Canadian Arctic to drill near gauge holes through permafrost. During the program, important practical information on foam drilling guidelines and operational considerations were obtained. The results indicate that the optimum foam quality for ensuring good hole cleaning varies with drilled depth and lithology. The data is presented in a graphical format which can be applied directly in the field.
Zistersdorf ÜT2A: Milling 867 ft of a 75/8-in.×56-lbm Q 125 Liner
Authors: Baldauf F. , Vock W. 
Published: December 2007

ABSTRACT
OEMV milled 867 ft (264.5 m) of 7 5/8″ × 56 # Q 125 liner to obtain good conditions for a sidetrack at 19 816 ft. The different types and designs of milling tools were subjected to a pilot test. A scale to scale model of the casing combination was submerged and anchored inside the conductor pipe of another well. The best results during the milling operation at a depth from 19 023 to 19 890 ft were achieved with tungsten carbide cutting elements with a diameter of 1/2″ and with a rhombic design.
Soil Farming of Oil Mud Drill Cuttings
Authors: Whitfill D. L. , Boyd P. A. 
Published: December 2007

ABSTRACT
In 1980 Conoco recognized the need for proper disposal of oil mud cuttings and has conducted both controlled "pilot-scale" soil farm studies and full scale field studies. Both the pilot scale and full scale studies show rapid reduction of hydrocarbons for both diesel oil and mineral oil base muds—up to 90 percent oil reduction within one year.
In addition to demonstrating the rapid reduction of oil, these studies also show the immobility of both hydrocarbons and heavy metals in the soil. The comparison of concentrations in the upper 1 foot of soil with those below 1 foot shows no increase in concentration of either hydrocarbons or metals by downward leaching.
These tests also show no preferential leaching of hydrocarbon species, with the relative fraction of both paraffins and aromatics decreasing with time and depth of sampling. Other studies of land farming processes have established a 5 weight percent oil-in-soil treatment level as being environmentally safe.
In summary, the soil farming of oil mud cuttings and drilling wastes is a viable and environmentally sound means of disposal.
The Causes of Shallow Gas Kicks
Authors: Goins W. C. , Abies G. L. 
Published: December 2007

ABSTRACT
Shallow gas blowouts have occurred worldwide. Short casing strings and low fracture gradients prohibit holding back-pressure, and wells can only be diverted. Under these conditions well control procedures are much less certain, and risk of cratering and loss of well is high. This places a great emphasis on kick prevention.
Well control schools tend to focus on deeper drilling and the peculiarities of shallow gas are not thoroughly addressed.
Due to the low margin of overbalance that exists on shallow sands, a small loss of hydrostatic pressure, easily tolerated in deeper drilling, can initiate flow into the wellbore. These conditions are illustrated and related to loss of circulation and hole filling during trips.
Drilling shallow gas sands too fast is examined as a potential mechanism for causing blowouts. Previous work in this area has shown that gas cut mud will seldom cause a blowout from the formation being drilled. While this is generally true, gas cut mud can lower the hydrostatic pressure enough to allow shallower formations to flow. A more comprehensive equation than heretofore published is developed, and several drilling parameters are examined to show their effects on the effective mud density at depths above the interval being drilled. A significant conclusion is that a sand might be drilled safely if casing is set just above the sand, but the same drilling conditions could cause an uncased, shallower sand to blow out.
The paper also shows that shallow gas sands which are normally pressured at the bottom of the gas interval can require higher mud weights to control formation pressures at the top of the gas interval. This is due to the difference between the gas gradient in the formation and normal formation gradient.
The 1987 IADC Fixed Cutter Bit Classification System
Authors: Winters W. J. , Doiron H. H. 
Published: December 2007

ABSTRACT
The International Association of Drilling Contractors (IADC) has adopted a new method for classifying fixed cutter (diamond) drill bits according to their design features. Seven design traits are described by a four-character code. The code applies equally well to drill bits and core bits with natural diamond, polycrystalline diamond compact (PDC), thermally stable polycrystalline (TSP) diamond, or any other type of fixed cutter elements.
Examples of typical fixed cutter bit designs are shown along with the appropriate IADC classification code.
Improvements in fixed cutter bit utilization are expected through use of the new IADC classification code in conjunction with the first ever IADC dull grading standard for fixed cutter bits.
Application of the New IADC Dull Grading System for Fixed Cutter Bits
Authors: Clark D. A. , Coolidge R. B. , Kelety J. T. , Kerr J. 
Published: December 2007

ABSTRACT
This paper describes a recently developed standardized system for dull grading natural diamond, PDC, and TSP (Thermally Stable Polycrystalline diamond) bits, otherwise known as fixed cutter bits. The new system is consistent with the recently revised dull grading system for roller bits. It describes the condition of the cutting structure, the primary (with location) and secondary dull characteristics, the gauge condition, and the reason the bit was pulled. Examples of all commonly seen dull characteristics of fixed cutter bits are given. In addition, several worn fixed cutter bits are dull graded using the system.
Application of the 1987 Roller Bit Dull Grading System
Authors: Hampton S. D. , Garris S. , Winters W. J. 
Published: December 2007

ABSTRACT
The IADC has adopted an improved rock bit dull grading system modeled after the previously used "T,B,G Remarks" approach. This paper discusses the improved system as it applies to roller cone bits (application of the new system for fixed cutter bits is presented in another paper). A complete definition of the system is given. Descriptions and possible causes of many dulling characteristics of roller cone bits are presented and briefly discussed. Some example dull bits are graded using the improved system. An application of the dull grading system as used in well planning is demonstrated.
Case History of Lowering Cost in Mature Field through Optimization Efforts
Authors: Brennan R. M. 
Published: December 2007

Abstract
Drilling and completion operations in mature fields have a long history of optimization efforts targeted towards performance improvements and minimum operational cost. While older fields are not typically regarded as prime candidates for major cost reductions, cost performance is essential for all areas in a time of declining oil prices. Exxon Company U.S.A recently established several cost reduction study teams to review mature field drilling and completion programs. Cost reduction without compromising overall objectives or jeopardizing operational safety was the goal of these study teams. Summarized herein is the methodology incorporated in one of the fields studied and the resulting twenty-two percent reduction in drilling and completion costs.
MWD Performance and Economic Benefits in the Zu Horizontal Drilling Program
Authors: Clary M. M. , Stafford T. W. 
Published: December 2007

Abstract
This paper describes the application of Measurement-While-Drilling (MWD) technology as used in a Horizontal Drainhole Drilling Program. The requirements of both formation evaluation and directional survey measurements while drilling will be discussed with reference to field results obtained. The ability of the MWD tool to make formation evaluation measurements, in order to identify casing seats and formation tops will be shown as essential to the project. The field examples described in this paper are from results obtained as part of the Atlantic Richfield Indonesia Inc. (ARII), 1986 ZU Field Development Drilling Program. The economic benefits of the utilization of MWD by ARII will be included.
MWD proved to be ideally suited to the directional drilling of high angle wells, and horizontal wells in particular. The placement of horizontal completions was critical, and very little deviation from the proposed well plan could be tolerated. Lithologic interpretation was critical to prevent drilling out of the top or bottom of the pay zone and MWD was sufficiently reliable to track the horizontal section of the wellbore. Wireline logs were eventually eliminated on later operations. The overall economic benefits of MWD were derived by comparing surveying costs and drilling time costs between similar wells drilled and surveyed conventionally versus those drilled using MWD.
An Experimental Investigation of the Performance of a 3-in. Hydrocyclone
Authors: Young G. A. 
Published: December 2007

ABSTRACT
A special 3 in. hydrocyclone with interchangeable pieces, which allowed all the dimensional parameters to be varied, was built. A two7 factorial test was run that identified which hydrocyclone parameters are most important with respect to flow rate and performance. A total of 450 tests of hydrocyclone performance have been conducted using one drilling mud. Based on these tests, a mathematical regression model was written which parameterizes the data for the test mud. The results of this model is presented graphically. These tests have shown that there is an optimum set of hydrocyclone dimensions which provide maximum separation. For the test mud, the performance of an optimum hydrocyclone is at least 25% greater than desilters presently utilized in the oilfield today. Dimensions for a hydrocyclone with near optimum separation which have a flow rate of 50 gpm are also presented. Utilization of optimum hydrocyclones will result in significant savings due to increased penetration rates and lower mud costs.
Financing of Oil and Gas Transactions
Authors: Bergen Richard C. 
Published: December 2007

Abstract
This paper considers the different ways of financing oil and gas transactions and points out that the financing method selected could be responsible for any given deal being much better, or worse, than anticipated by the engineers. In the drilling of wildcat prospects, for instance, the carried interest or the free-well type of contractual agreement could have entirely different consequences depending upon the particular form taken by the agreement. Also, when a proven well is financed by the carving out of an oil payment, a very substantial difference results if the oil payment is pledged to the development of the property. Financing of the purchase of producing properties by the so-called ABC procedure could result in the purchase price of a property being largely paid for by the proceeds from production without diminution due to income taxes.

Introduction
The function of this paper is to discuss the various possible methods of investing in or borrowing upon oil and gas properties, pointing out the advantages and disadvantages of using one method rather than another. The particular method selected can, and does under our tax laws, make a tremendous difference in the economics of the venture. For instance, if one method would result in the imposition of a Federal income tax on the production in question at the maximum corporate rate of 52 per cent and if another method would substantially avoid the imposition of this tax, it is evident that the method which would avoid the tax could make the venture twice as attractive as would otherwise be the case. As will be seen later, this is not simply a theoretical possibility; accordingly, tax planning in the oil and gas field leaves plenty of room for an inventive tax attorney.
Diverting Agents: Laboratory Study and Modeling of Resultant Zone Injectivities
Authors: Doerler N. , Prouvost L. P. 
Published: December 2007

Abstract
A methodology for the design of the diversion stages of matrix acidizing jobs is presented. The resistance to flow induced by a cake of diverting agent deposited at the sandface of a single core has been measured in the lab under a large variety of conditions, representative of those encountered downhole.
The experimental data are then combined with a numerical model to yield a design tool for diversion jobs, which enables to predict the flow distribution due to diverters in multi-layered formations, according to both reservoir and diverter properties.
Finally, results obtained with the model are presented, to demonstrate how it can be used to optimize the volume of diverter slugs in matrix acidizing treatments.
Alumina Precipitation in Porous Media for Profile Control
Authors: Torrest R. S. , Huang S-H. 
Published: December 2007

Abstract
The precipitation of hydrated aluminum oxide from aqueous solutions can be controlled with reactions that change solution pH. Gels, fine grained precipitates and tightly adhering coatings can be readily produced within porous media to provide profile control. Substantial permeability reductions to over 99% were achieved with small amounts of gels not only in a 5 darcy sand, but also in relatively coarse 20/40 mesh glass beads and gravel. Laboratory results show the influence of injection volume and rate on overall permeability reduction. Profiles for permeability and gel content were also measured. Gel size distributions from static and plugging experiments show the development of sizes leading to effective control.
Optimization of Vertical Acid Fractures in Steady-State Flow
Authors: Sevougian S. D. , Schechter R. S. , Sepehrnoori K. 
Published: December 2007

Abstract
The first step in the formulation of acid-fracturing fluids is to specify an optimal range for each of the fluid properties. To do this, a new procedure is developed for the optimization of hydraulic acid-fracturing treatments. This procedure first predicts the optimum fracture geometry, namely, the geometry which maximizes the stimulation (or productivity) ratio for a given acid volume and then identifies the fracture fluid properties needed to create this geometry.
By utilizing the calculus of variations, an analytical solution is found for the optimum fracture geometry. This solution has several important features. First, the optimum dimensionless fracture shape (conductivity profile or acid-spending profile) in undamaged reservoirs is invariant with respect to both acid volume and formation properties; and, furthermore, this shape is nearly uniform (i.e., constant conductivity) over the entire length of the fracture. Second, the optimum length is a function of a single dimensionless variable. Third, the optimum shape (acid-spending profile) in damaged reservoirs is nearly the same as in undamaged reservoirs and essentially independent of the extent of damage, so long as the fracture extends beyond the damaged zone.
By combining the variational solution for optimum fracture geometry with existing analytical models of the acid reaction and fracture growth processes, it is possible to define ranges of fluid properties which will yield a treatment closely approximating the optimum one. The primary conclusions reached by this method are that the Peclet number for viscoεified acids must be large, approximately 4.0, to achieve the optimal shape; and that optimal fluid-loss coefficients are greater than those previously thought desirable. In fact, it appears that fluid loss except in highly fissured or vuggy carbonate formations is not a critical design variable. Furthermore, very low injection rates or relatively high diffusion coefficients may require unacceptably high acid viscosities.
High-Temperature/High-Pressure Solubility Measurements in the Systems BaSO4-NaCl-H2O and SrSO4-NaCl-H2O in Connection With Scale Studies
Authors: Schulien S. 
Published: December 2007

ABSTRACT
Solubility data on BaSO4 and SrSO4 have been determined in the temperature range 353 to 393 K at pressures up to 41,4 MPa (6000 psi) and at ionic strength of NaCl brines between 0.1 and 2.0 M. The experiments were performed in a high temperature/high pressure test equipment by applying the dissolution technique. The experimental results confirm the general trend in solubility dependencies for both BaSO4 and SrSO4, determined at lower temperatures and pressures: pronounced increase in solubilities of BaSO4 and SrSO4 with increasing ionic strength, slight increase in solubilities when pressurizing the solutions up to 41.4 MPa. A temperature rise from 353 to 393 K causes an increase in BaSO4 solubility, but a decrease in SrSO4 solubility. Calculation of the solubility products reveals for BaSO4 an increase from 1.1 • 10−10 in pure water at 298 K and normal pressure to 5.1 • 10−8 in 2M NaCl brines at 393K and 41.4 MPa. For SrSO4 the solubility product increases from 2.8 • 10−7 in pure water at 298 and normal pressure to 18.2 • 10−7 at 373 K and 41.4 MPa and to 16 • 10−7 at 393 K and 41.4 MPa in 2M NaCl brines.
Development and Evaluation of EOR Polymers Suitable for Hostile Environments: II—Copolymers of Acrylamide and Sodium AMPS
Authors: Moradi-Araghi A. , Cleveland D. H. , Westerman I. J. 
Published: December 2007

Abstract
Copolymers of acrylamide (Am) and sodium-2-acrylamido-2-methylpropane sulfonate (NaAMPS) have been evaluated for flooding applications at elevated temperatures. The brines employed in this study include synthetic seawater (447 ppm Ca++, 1256 ppm Mg++ and 33,560 ppm TDS) and others containing a It 10 weight ratio of CaCl2 to NaCl and having TDS ranging from 0.55 to 16.5%. AMPS is a registered trade mark of the Lubrizol Corporation.
While NaAMPS homopolymer solutions are thermally stable at 121°C (250°F), and hydrolyze very slowly and to about 4% after extended aging, copolymerization of NaAMPS with acrylamide does not appear to protect the later against thermal hydrolysis and consequent precipitation in hard brines. Only Am-NaAMPS copolymers containing less than 9 wt.% Am might tolerate a brine such as seawater at 121°C (250°F). Comparison of these results with those reported for vinylpyrrolidone (Vp) and acrylamide copolymers which showed stability for a copolymer containing 50 wt.% Am in seawater at 121°C (250°F) is evidence that Vp protects acrylamide against thermal hydrolysis, but NaAMPS does not.
Evaluation of various weight ratios of Am-NaAMPS copolymers for flooding applications at 93°C (200°F) resulted in an optimum composition near 40/60 wt. ratio of Am/NaAMPS. Given the fact that polyacrylamides are suitable for flooding applications up to 75°C (167°F), inclusion of about 60 wt.% of a more expensive NaAMPS monomer into the copolymer composition to increase its usability limit by less than 20°C (36°F), does not appear economically viable. It is believed that many of the so called "high temperature" polymers commercially available, are NaAMPS based materials containing high levels of acrylamide and are not suitable for polymerflooding at temperatures significantly higher than those of polyacrylamide.