bluuebunny/crossref_metadata_2025_split huggingface dataset:
Analysis of Temperature Distribution and Performance of Polycrystalline Diamond Compact Bits Under Field Drilling Conditions
Authors: Zijsling D. H. 
Published: December 2007

ABSTRACT
Analysis of laboratory tests on full-scale field-worn polycrystalline diamond compact (PDC) bits showed the frictional heat at the rock/bit interface to be largely generated at the diamond cutting edges of the PDCs. Inspection of the observed wear of the PDCs together with the analysis revealed that the diamond layer attacks the formation at a large negative rake angle and that rock flour accumulates under the cutting edge during drilling, forming a stable buildup edge.
A thermal model has been developed on the basis of these results to predict the temperature distribution in the PDCs under quasi-static drilling conditions. The maximum temperature is found to occur at the PDC's cutting edge and is virtually independent of PDC position under normal rotary drilling conditions. At elevated rotary speeds however, the maximum cutting edge temperature occurs in PDCs at the gauge of the bit. This temperature can exceed the boiling point of water-based drilling fluids, resulting in higher cutting edge temperatures and wear rates of the PDCs which may lead to premature failure of the bit. Under normal rotary drilling conditions the maximum cutting edge temperature increases with the penetration rate. For the higher speed positive displacement motor drilling applications however, bits can be designed to give a virtually constant maximum cutting edge temperature over a wide range of bit penetration rates. This is achieved by selecting the optimum number of cutters whilst making use of the thermal insulating capacity of the buildup edge under the PDC. In addition a further reduction In the maximum cutting edge temperature can be achieved at these speeds by reducing the diamond layer thickness of the relevant PDCs.
The results also showed that for effective cooling of the PDCs fluid velocities of at least 50 m/s are required along the diamond surfaces when drilling with oil-based fluids. With water-based drilling fluids, higher velocities should be used to prevent bit balling or boiling of the drilling fluid at the diamond surface of the PDCs.
The Interpretation of Tracer Test Response from Heterogeneous Reservoirs
Authors: Smith P. J. , Brown C. E. 
Published: December 2007

ABSTRACT
Tracer testing is an increasingly used tool for reservoir characterisation. Hitherto either qualitative results (such as preferential flow paths) or simple conceptual models for the reservoir variability (such as layering) have been used. These studies allow a more general class of heterogeneous reservoirs to be investigated.
The results confirm that the characterisation of reservoir heterogeneity from tracer response requires both a measure of the dispersivity plus a knowledge of the correlation scale length and variability within the reservoir. The application of this work will have particular significance to the characterisation of reservoirs prior to the prediction of EOR schemes.
Role of Roughness and Edges During Imbibition in Square Capillaries
Authors: Lenormand Roland , Zarcone Cesar 
Published: December 2007

ABSTRACT
The displacement of one fluid by another in a two-dimensional etched network has been described at the microscopic level: during imbibition, the wetting fluid can flow through the roughness of surfaces, along the edges of the ducts (rectangular cross-section) or in the bulk of the ducts. In this paper, we present results for the time scales of these different mechanisms and the consequences for imbibition in large 2-dimensional networks of capillaries and approximate laws for the flow rates by roughness and corners are calculated in an infinitely long square duct. A theoretical model is built for describing the relationship between the fluid configuration and the Capillary Number (or flow rate):
VERY LOW FLOW RATE: The wetting fluid can reach all the parts of the network by flowing along the surface roughness. It begins to fill the bulk of the smallest ducts and the number of filled ducts increases with time. This is a Cluster growth mechanism. LOW FLOW RATE: The wetting fluid can flow along the corners of the ducts but not through the roughness. The mechanism is like Invasion Percolation but the wetting phase flows along the grains of the solid in a special network called: DUAL network. HIGH FLOW RATE: The wetting fluid only flows in the bulk of the ducts and the mechanism is a Frontal Drive without fingers nor trapping of the nonwetting phase.
Reservoir Management of the Bryan (Woodbine) Field
Authors: Givens J. W. 
Published: December 2007

Abstract
The Bryan (Woodbine) Field is a major oil reservoir which was recently discovered in Southeast Texas. The initial reservoir performance, reservoir rock properties, and reservoir fluid data indicated that the reservoir pressure would soon be depleted below the bubble-point pressure. The operators and working interest owners in the field realized the need for unitization in order to maximize the ultimate recovery from the reservoir and therefore began cooperative discussions and regular meetings early in the reservoir life. Because the reservoir is located largely under the city limits, there are a number of unique problems related to development and unitization. A unitization formula has been negotiated and the Unit Agreement is being circulated for ratification. Engineering studies of secondary recovery by waterflooding are in progress.
The purposes of this paper are (1) to present the geology, performance history, and reservoir parameters of the Bryan Field, (2) to describe the unitization process and its status, and (3) to discuss enhanced recovery alternatives.
The Tertiary Extension of the Wizard Lake D-3A Pool Miscible Flood
Authors: Backmeyer L. A. , Guise D. R. , MacDonell P. E. , Nute A. J. 
Published: December 2007

ABSTRACT
A tertiary extension of the existing secondary hydrocarbon miscible flood in the Wizard Lake D-3A Pool was implemented in October, 1983. The extension will result in the oil-water contact being lowered 22.6 meters (74.1 feet) to allow miscible displacement of the residual oil in the water flushed portion of the reef. This water flushed zone was formed when the oil-water contact rose during primary depletion of the reservoir from discovery in 1951 until the implementation of the secondary miscible flood in 1969, and also during the repressuring phase of the secondary miscible flood. Ultimate recovery from the pool is expected to be 59 539 103m3 (374.49 MMSTB) or 95.95 percent of the original oil-in-place; which is 4 531 103m3 (28.50 MMSTB) higher than the secondary miscible flood and 18 583 103m3 (116.88 MMSTB) more than under primary depletion.
This paper reviews the implementation and monitoring of the tertiary extension of the miscible flood and also the performance of the pool to January 1, 1984.
Design and Implementation of a Miscible Water-Alternating-Gas Flood at Prudhoe Bay
Authors: Rupp K. A. , Nelson W. C. , Christian L. D. , Zimmerman K. A. , Metz B. E. , Styler J. W. 
Published: December 2007

ABSTRACT
An enriched, Water-Alternating-Gas (WAG), miscible flood was brought on stream in December 1982 in the Prudhoe Bay Field on Alaska's North Slope. This paper outlines details of the Project and traces its evolution from conceptual engineering through start-up to initial performance.
The Project involves an area containing 442 million barrels original oil in place. The 3,650 acre Project Area includes sixty 80-acre spaced wells in eleven inverted nine-spot patterns. Facilities process the 40 to 45 MMscf/D of miscible injectant which is then injected alternately with water on a 3 month/6 month gas/water cycle in eleven injection wells. An extensive surveillance program includes one fiberglass cased observation well, a comprehensive cased hole logging program, and radioactive gas tracers. The Project will consist of WAG injecting a slug of more than 10% total pore volume (TPV) miscible gas. The miscible gas will be injected at a rate of approximately 1% TPV per year, followed by. water injection to displace miscible gas through the reservoir and tertiary oil to producing wells. The estimated incremental-to-waterflood recovery is 5.5% of the original oil in place or 24 million barrels of oil.
Comparison of Digital and Analog Techniques for Determining Sonic Velocity from Borehole Acoustic Waveforms
Authors: Wu P. T. 
Published: December 2007

Abstract
Analog threshold detection, or the first motion detection (FMD) method, has been the traditional method for estimating formation compressional slowness. Recent advances in the design of wireline acoustic tools now allow near simultaneous acquisition of sonic waveforms from a downhole multireceiver array. Kimball and Marzetta1 proposed a digital method based on semblance called slowness-time-coherence (STC) to determine the slowness (Δt) of all coherent components of the waveforms. The purposes of this paper are to compare and explain the differences between the compressional slowness obtained from the FMD and the STC methods under different formation conditions.
The Analysis of the Invaded Zone Characteristics and Their Influence on Wireline Log and Well-Test Interpretation
Authors: Phelps G. D. , Stewart G. , Peden J. M. 
Published: December 2007

ABSTRACT
This study examines the invasion of a hydrocarbon bearing formation by drilling fluid filtrate, and investigates, with the aid of a numerical model, the significance of capillary forces on the resulting displacement.
It is observed that in high permeability zones, capillary imbibition can draw filtrate into the formation faster than it is lost through the filtercake, which is assumed to control the fluid loss rate.
On the basis of conclusions drawn from the numerical study, the phenomena of supercharging (the difference between the water phase pressure at the sandface and the undisturbed formation pressure) has been reanalysed, and an equation recognising supercharging as a two phase problem is presented. Depending on the character of the displacement, supercharging in a hydrocarbon zone can be enhanced or reduced due to the presence of mud filtrate.
A field example is used to validate the proposed theory, as well as to demonstrate how the down hole static fluid loss rate may be determined from repeat formation tester (RPT)* based measurements.
A New Approach to Casing Design for Salt Formations
Authors: Hackney R. M. 
Published: December 2007

ABSTRACT
Data from over forty incidences of casing collapse in the Midcontinent area is used to develop a new design method for casing to be set across salt formations. The new method reduces overdesign of casing 37% over hydrostatic collapse designs while predicting all failures. This design method involves modification of the standard Von Mises equations to account for the nonuniform collapse loads generally presented by salt formations. The modification involves use of curved beam theory and correlation to field data. It is valid across the midcontinent region and may be adapted to other areas. Additionally, tight casing due to excessive elastic deformation may be considered as well as failure due to plastic collapse.
Discussion includes current industry design methods and the mechanics of formation flow.
Thermally Stable Synthetic Diamond Drill Bit Proves Effective in Gulf Coast
Authors: Stoddard J. , Cerkovnik J. 
Published: December 2007

ABSTRACT
A new thermally stable diamond cutter has proven effective in drilling medium to hard limestone and moderately abrasive sand. This new type of diamond is called "Ballas" which is a synthetic polycrystalline diamond. Ballas can be thought of as a more refined, or pure, polycrystalline diamond compact cutter which is free of foreign material within or attached to the diamond mass. The Ballas cutter is thermally stable up to 1200 degrees C compared to a conventional polycrystalline diamond compact which is only thermally stable up to 750 degrees C. This additional temperature resistance allows the use of self sharpening polycrystalline diamond to be used in harder, more abrasive formations which cannot be cut with the present diamond compact material.
The use of the Ballas material has shown significant rate of penetration advantage in drilling the carbonate formations of East Texas and the depleted sands of So. Louisiana. Along with the success, present bit designs have experienced some problems drilling some of the clean plastic shales common on the Gulf Coast.
The Rise and Fall of the Offshore Contract Drilling Industry, 1979 to 1983
Authors: Rankin M. D. 
Published: December 2007

Abstract
As the offshore contract drilling industry moves into its third decade, it faces a number of serious and expensive problems which defy easy solutions. Over a period of three years, the industry has been transformed from a thriving, profitable business into one of incredible surplus capacity and economic margins insufficient for long term survival.
Few other industries can claim the level of capital growth and entrepreneurship which has been the trademark of the contract drilling business. The industry is largely free of commercial regulation although a number of developing countries have implemented policies which severely limit the ability of private concerns to enter the market. By and large, offshore contract drilling is a textbook example of the free marketplace-living and dying by the double edged "sword" of supply and demand.
The purpose of this paper involves a general assessment of industry performance over the period 1979-1983, years which encompass the latest "boom-bust" cycle. The analysis is intended to be an objective assessment, rather than an indictment, with the hopeful result that the industry will eventually profit from the less fortunate aspects of the recent past.
Air Drilling Practices in the Midcontinent and Rocky Mountain Areas
Authors: Sheffield J. S. , Sitzman J. J. 
Published: December 2007

Abstract
This paper is adapted to air drilling in the Midcontinent and Rocky Mountain areas. A compilation of operational experience and design data dealing with air drilling is explained and summarized.
Discussion includes when and when not to air drill, how to plan for air drilling, and different drilling strategies employed during air drilling operations.
Operational experience is reviewed in several Rocky Mountain areas and in Arkansas. Air drilling has proven to be a significant factor in reducing drilling costs in these areas. Conclusions and recommendations are made with regard to the major areas discussed in the paper concerning what well conditions lend themselves to air drilling, and when to use mist, inhibited mist or foam.
Methods to utilize air drilling to its fullest potential such as the use of air hammers and polymer foam drilling are also discussed.
Design Outline for a Microcomputer Drilling Management Program
Authors: Weatherspoon R. L. 
Published: December 2007

ABSTRACT
This paper outlines the design considerations and performance criteria of a microcomputer program developed for drilling management. The program utilizes existing daily report procedures used in most offices to build an on-site well information data base. The data base is then used for real-time operations optimization, report generation, and subsequent well analysis. It is totally self-contained for use on IBM-XT microcomputer. The outline, while specific to the IBM-XT, can be used by any data processing department to structure their own drilling management system for micro, mini, or mainframe computer installations.
The Well Testing Program at the Heber Geothermal Field
Authors: Da Sie W. J. , Hoang V. T. 
Published: December 2007

Abstract
In 1984, Chevron Geothermal Company of California embarked on the drilling and testing of geothermal development wells for the Dravo dual flash and San Diego Gas and Electric binary plant both scheduled for startup in 1985. This paper describes the methods and special techniques used in processing and analyzing the large volumes of pressure data gathered during the extensive single well and interference testing program. A summary of the testing results is presented which show the Heber reservoir to be of high quality with excellent communication between the wells drilled. Special phenomena observable in some of the interference testing results, possibly related to spatial transitions in reservoir characteristics, are described in some detail.
Hydraulic Fracture Growth During Steam Stimulation in a Single-Well Test
Authors: Holzhausen G. R. , Card C. C. , Raisbeck J. M. , Dobecki T. L. 
Published: December 2007

Abstract
Ground deformation was monitored for nearly ten weeks during the first cycle of steam stimulation in a single-well test using an array of high-resolution borehole tiltmeters. The test was conducted in a section of the Athabasca oil sands having properties similar to the unconsolidated oil sands of California. The 310-meter injection depth was also comparable to the depth of thermal stimulation in many California oil fields. Ground response indicated that steam injection was not a continuous process, but rather was characterized by numerous episodic events. During these events wellhead pressure dropped (in one case by 2650 kPa), boiler feed rate increased by a few percent, and the ground surface within the instrument array was lifted up. Pressures again began to rise and the ground surface subsided within a few hours of the beginning of an event, but subsidence always preceded pressure increase. The magnitudes of the pressure and deformation changes varied from event to event, apparently unsystematically.
The events are interpreted to have resulted from breakdown of the oil sands and attendant propagation of hydraulic fractures away from the wellbore in approximately horizontal planes. Larger fractures may have continued to propagate until internal pressures were insufficient to lift the overburden, at which time they collapsed. Fracture growth terminated at higher pressures in events for which deformation changes were small, perhaps because of inelastic blunting of the fracture tips. Modelling suggests that the radii of fractures formed in the larger events may have been about 160 meters, whereas those formed in the smallest events had radii of about 40 meters.
A delay of three weeks between the start of steam injection and the occurrence of the first episodic event suggests that there may have been major modification of the in-situ stress state during this period. Pressure records from cold-water hydraulic fracturing a week before the start of steam injection indicate that this fracture was vertical, from which we infer that the most compressive component of in-situ stress was also vertical. Gradual heating of the oil sands during steam injection should have closed the vertical fracture by thermal expansion, and then led to an increase of horizontal compression as further lateral expansion was suppressed. Formation of horizontal fractures after three weeks of steaming is consistent with a modified in-situ stress state in which horizontal exceeded vertical compression.
Steady-State Analysis of In-Situ Combustion
Authors: Agca C. , Yortsos Y. C. 
Published: December 2007

ABSTRACT
The success on an in-situ combustion project depends primarily on the development of a stable combustion front, which propagates at constant velocity, and sustains a constant temperature high enough for the efficient mobilization of the original reservoir oil. To determine the conditions favoring a stable combustion front, a numerical solution of the equations describing conservation of mass and thermal energy is typically implemented using thermal simulators.
In this paper, an alternative simplified steady-state analysis is attempted by treating the combustion region as a moving zone of constant length, within which the oxidation reaction is taking place. Steadystate solutions are obtained which relate the combustion characteristics, such as front velocity, combustion temperature, and reaction extent, to the reservoir and process parameters. In particular, the effects of reservoir thickness, heat losses to surrounding formations, initial reservoir temperature, injection rate, and injection pressure are analyzed.
It is found that, for typical values of the parameters three steady-state develop, one at a low temperature near the initial reservoir temperature, and one at a sufficiently high temperature, both of which are stable, and one at intermediate temperatures, which is unstable. In such cases, preheating (ignition) near the injection well is necessary for the desired steady-state at the higher temperature to be reached. The region in the values of the parameters where such behavior occurs is numerically determined. It is also found that single steady-states may develop, either at a low temperature implying an unsuccessful combustion project, or at a high temperature implying spontaneous ignition. Conditions are obtained that determine the range in the values of the parameters where such cases prevail.
The steady-state results indicate that the combustion temperature increases with an increase in reservoir thickness, injection rate and injection pressure. The front velocity was found to vary almost nearly with the injection rate, although it is rather insensitive to the values of most of the other parameters. The combustion reaction reaches completion at higher temperatures.
The simple analysis presented here delineates the range of the values of the reservoir and the process parameters that would result into favorable combustion characteristics and thus a successful in-situ combustion project. The numerical results obtained agree both qualitatively and quantitatively with field values previously reported for successful in-situ combustion projects.
Pressure Transient Analysis for Single Well/Reservoir Configurations (Considering Partial Penetration, Mixed Boundary, Wellbore Storage, and Skin Effects)
Authors: Theuveny B. C. , Jack W. A. , Economides M. J. 
Published: December 2007

Abstract
This work presents a set of solutions for pressure transients analysis demonstrating the flexibility of Green's functions In solving a wide range of problems.
The Impact of partial completions and offoentered wells is presented along with a first-time Incorporation of wellbore storage and skin effects. Custom type-curves tailored to fit any well, reservoir and boundary configuration may be generated using the methods outlined here. An associated computer model is fully interactive and can be run on a small computer, readily available to most reservoir engineers.