bluuebunny/crossref_metadata_2025_split huggingface dataset:
Trajectory Equations for Constant Tool Face Angle Deflections
Authors: Schuh F. J. 
Published: December 2007

ABSTRACT
Prior to the introduction of steering tools and MWD survey equipment, all deflection tools produced circular arc deflections. In order to drill a circular arc deflection the directional driller must change the tool face angle during the course of the correction. With modern bent housing motors and MWD or steering equipment, it is easier and more precise to make corrections using constant toolface angles. Holding a constant tool-face angle produces a uniform vertical build rate which is especially useful for the horizontal driller. This paper presents the derivation of the trajectory equations for drilling constant toolface deflections. The paper also includes both the equations as well as several forms of graphic solutions.
Performance of Rock Bits in the 17½- and 14¾-in. Sections of Germany's Ultradeep KTB Well
Authors: Wohlgemuth Lothar , Meany N. C. , Reinsvold C. H. 
Published: December 2007

Abstract
The Continental Deep Drilling Program of the Federal Republic of Germany (Kontinentinales Tiefbohrprogram der Bundesrepublik Deutschland - KTB) is drilling ahead on its planned 10, 000-meter (32, 808-ft) investigatory borehole in Bavaria, which is expected to reach total depth in 1994. Designed to research the earth's crust, the program was initiated with a pilot hole completed in April 1989 to a total depth of 4000 meters (13, 123 ft). The majority of the pilot hole was cored and the data obtained proved invaluable in planning for the current well, which is located 200 meters (656 ft) east of the pilot hole. Drilling of the current well commenced in October 1990.
Rolling cutter bits were specially designed for drilling the hard crystalline rock. The highly abrasive formations and elevated temperatures, coupled with expected deviation problems, mandated bits be developed to withstand the extremely hostile downhole environment. The bit design program focused on maintaining gage and enhancing bit life under the uniquely challenging downhole conditions.
This paper will discuss the design and performance of a variety of rolling cutter bits used in the 17 1/2″ and 14 3/4″ sections of the borehole, consisting primarily of gneiss and amphibolite rock. The performance of the first 50 bits will be analyzed.
Quality Assurance for Field Mud Testing Equipment
Authors: Geraghty S. , Motley T. 
Published: December 2007

ABSTRACT
The functional properties of drilling fluids are critical to safe and economic drilling operations. It is fundamental that equipment in use to check drilling fluid properties is operating correctly within clearly defined limits and documented accordingly. It is important that any procedure is documented concisely and is sensibly applicable under wellsite conditions.
This paper examines the development criteria, implementation of calibration and function testing procedures of drilling fluid testing equipment used by mud engineers at the wellsite. Set protocols establish standard methods and certificates of analyses establish standard reporting procedures.
Distinction is made between function testing, a quick simple field engineer's check, and calibration for equipment which fails the function test and requires repair. Not only are operational parameters examined but also safety aspects, especially with regard to pressurised equipment.
Although several calibration procedures are known for certain pieces of equipment (rheometers and retorts) these are often impractical for wellsite application. The procedures require special calibration equipment or are onerous to perform and therefore neglected. Many heuristic procedures in use are wrong.
The formalised and documented methodology presented here provides the quality assurance necessary for the work being done. This ensures greater consistency of data and confidence in it. Regularly performed function tests alert the field engineer as to the accuracy of data and quality of measurements.
In conclusion, field engineer response to implementation will be examined with a discussion on the benefits, problems and findings.
The Internal Pressure Capacity of Crescent-Shaped Wear Casing
Authors: Song J. S. , Bowen Jerry , Klementich Frank 
Published: December 2007

Abstract
Drill pipe operations inside casing produces a crescent-shaped wear pattern. Such wear can compromise the design integrity of the casing string. The lack of an adequate method of calculating the rupture pressure of crescent-shaped wear casing prevents an accurate assessment of the true safety factor of the string, as opposed to the strings initial yield pressure design factor. This paper presents an accurate method for calculating the internal rupture pressure of crescentshaped wear casing as verified by experimental results. The true safety of the string can thus be assessed and operations adjusted accordingly.
Development of a Cartridge Data Transmission System for Use with Air Drilling Motor
Authors: Shale Les , Moberley G. T. 
Published: December 2007

ABSTRACT
A cartridge data transmission (CDT) system has been developed for use when drilling with air and gas. The CDT system employs a steering tool that allows orientation of the drilling motor in a particular direction, while still allowing drilling straight ahead with drillstring rotation. The system can be easily converted for fluid drilling where this "poor man's MWD" has real economic and operational advantages.
The CDT system uses a specially ruggedized steering tool which provides continuous surface readout of drift angle and azimuth of the hole, as well as toolface orientation while drilling ahead. A hard wire from the steering tool through the drill pipe and kelly to the surface, relays information to computerized surface equipment. Date transmitted from the steering tool is updated and converted instantly to information which can be used to make any necessary corrections to the motor to ensure the target is reached and the well completed.
Application of Soft-Torque Rotary Table in Mobile Bay
Authors: Javanmardi Kazem , Gaspard D. T. 
Published: December 2007

ABSTRACT
Shell Offshore Inc. (SOI) has successfully installed and operated the Soft Torque Rotary System (STRS) for the first time on two drilling rigs operating in Mobile Bay. Application of the STRS has significantly reduced torque fluctuations (up to 80%), torsional drill string vibrations, and bit slip-stick conditions. The STRS attenuates and interrupts the torsional oscillations of the drill string and thus prevents the buildup of energy in torsional waves that are reflected back and forth between the bit and the rotary table. It can be installed on any rig equipped with an independent electronically driven rotary table or top drive. The STRS is inexpensive (about $25M for Shell group companies), easy to install, and has been a factor in improved drilling penetration rates realized on the SL 531 No. 3, a complex directional well drilled in the Mobile Bay area. Additionally, the STRS has been instrumental in avoiding expensive ($5MM-$10MM) drill string failures on the SL 531 No. 3. Further work needs to be done to fully quantify the impact of the STRS on reducing these types of failures.
Surfactant/Cement Blends Improve Plugging Operations in Oil-Base Muds
Authors: Harder C. , Carpenter R. , Wilson W. , Freeman E. , Payne H. 
Published: December 2007

ABSTRACT
Achieving a competent kick-off plug can be a difficult task, especially when cementing in oil-base mud (OBM). Historically, kick-off operations in OBM have required numerous costly and time consuming attempts to establish a good plug.
Portland or hydraulic cements require water wetting of their chemical components to initiate and maintain the hydration process. If the hydration process is interrupted, so is strength development. OBM impedes cement hydration by oil-wetting the cement components. Laboratory testing indicates as little as 10% by volume OBM mixed with cement can dramatically affect cement thickening time and compressive strength (see Figure 1 and Figure 2).
Cements mixed with water-wetting surfactants have significantly improved plug success rates in an area where plug failures in OBM were commonplace. The water wetting surfactant used in these tests effectively reduced the OBM contamination. Compressive strength, thickening time, and rheological testing have shown surfactant/cement blends to be more tolerant of OBM contamination (see Table 1). In field tests, using surfactant cements, only one attempt was required to establish a competent kick-off plug. In a three well program, a $2000 surfactant expenditure produced a projected $300,000 savings.
Sensitivity of Early Kick Detection Parameters in Full-Scale Gas Kick Experiments With Oil- and Water-Based Drilling Muds
Authors: Anfinsen B. T. , Rommetveit Rolv 
Published: December 2007

ABSTRACT
Gas kicks in oil- and water-based mud have been studied in an inclined research well. One of the main objectives has been the study of early kick detection. Data on pit gain, stand pipe pressure and mud return flow have been systemized in all the kicks in order to evaluate the performance and sensitivity of these parameters. The sensitivity of the detection parameters have also been compared for various kick types. The results show that several surface detection parameters are necessary in order to optimize detection. The reduction in pit gain due to gas solubility in OBM is shown to be significant The mud return flow was the most sensitive parameter in OBM. In WBM also pit gain and stand pipe pressure were valuable for kick detection. New detection signs have been found on the return flow signal in OBM and in kicks with MWD pressure pulsing.
An Evaluation of Flowmeters for the Detection of Kicks and Lost Circulation During Drilling
Authors: Schafer D. M. , Loeppke G. E. , Glowka D. A. , Scott D. D. , Wright E. K. 
Published: December 2007

ABSTRACT
An independent evaluation of current industry standard and state-of-the-art drilling fluid inflow and outflow meters was conducted during the drilling of a geothermal exploratory well. Four different types of fluid inflow meters and three different types of fluid outflow meters were tested and evaluated during actual drilling operations. The tested drilling fluid inflow meters included conventional pump stroke counters, rotary pump speed counters, magnetic flow meters, and a Doppler ultrasonic flow meter. On the return flow line, a standard paddle meter, an acoustic level meter, and a prototype rolling float meter were evaluated to measure drilling fluid outflow rates. The prototype outflow meter utilizes a rolling float which rides on the surface of the flow thereby measuring the fluid height in the pipe. Both die prototype meter and the conventional paddle meter were also extensively tested under a variety of drilling conditions in a full-scale laboratory test facility. The meters were evaluated and compared on the basis of reliability and accuracy, and the results are presented in the paper.
Effectiveness of Conditional Simulation To Describe Carbonate Reservoir Properties
Authors: Perez Godofredo , Kelkar B. G. 
Published: December 2007

Abstract
Conditional simulation is a geos tat is tic al approach to generate multiple equiprobable distributions of a property with specified univariate and spatial attributes. These attributes are derived from sample data or inferred from external infor-mation. This paper evaluates the effectiveness of conditional simulation to describe distributions of porosity in a carbonate environment.
The reservoir studied produces from a dolomitized for-mation of complex lithology. The conditional simulation methods tested are the simulated annealing simulation (SAS) and the sequential indicator simulation (SIS). A validation procedure is introduced to compare observed and simulated porosity distributions and to quantify the quality of two- and three-dimensional conditional simulations. Results of three-dimensional validations indicate that SAS yields a good overall reproduction of observed porosity distributions. Comparisons of equiprobable two-dimensional distributions suggest that the quality of the porosity descriptions for SAS are slightly better than for SIS.
These results show that conditional simulation renders descriptions which capture variations of a property due to inherent geologic complexities. The major advantages of conditional simulation over traditional methods are: (l) it incorporates in a distribution of a property different degrees of variability for different directions, and (2) it accounts for uncertainties in the description.
The Effect of Delayed Enzyme Breakers on Filter Cake Cleaning in Southeastern New Mexico Stimulation Jobs
Authors: Laramay S. B. , Norman L. R. , Carathers B. K. 
Published: December 2007

ABSTRACT
Enzymes are useful breakers in water-based fracturing fluids, but delaying the release of the enzyme provides many advantages. These advantages include delaying the break of the fluid to provide improved fluid rheology, increased breaker concentration improves fracture conductivity and a solid filterable breaker concentrates the added breaker in the fracture. These advantages will lead to better proppant placement and improved production increases.
A study of the interdependence of temperature and pH on enzyme activity was investigated. These results indicated the limitations of enzymes as breakers in fracturing fluids, but the lifetimes of enzymes at higher pH and temperature were longer than expected. Laboratory investigation of improved fluid performance was investigated using delayed static break time, improved viscosity profiles, and filter cake dissolution study. Static break times were significantly longer than normally obtained in typical low temperature fracturing fluids with conventional enzyme breakers. This also resulted in better viscosity profiles especially in early time. Filter cake dissolution studies pointed to the usefulness of the delayed release enzyme breaker in cleaning filter cakes prepared from linear and borate crosslinked gels, but fluids crosslinked with metal ions were not cleaned.
Actual field trials made in a Southeastern New Mexico study wherein the delayed release enzyme breaker was used also point to the effectiveness of the delayed release enzyme breaker in improving fluid performance. Increased initial water production and sustained oil production were the results when the delayed release enzyme breaker was used. Another facet of the protection of the enzyme in high pH fracturing fluid was also examined. The delayed release enzyme breaker was successfully used in a pH 9.5 fracturing fluid.
Perils to the Free World's Essential Oil Supplies
Authors: Levy Walter J. 
Published: December 2007

The Free World Depends Increasingly on Foreign Oil
Since the beginning of World War II foreign oil has gained an ever greater importance in the oil supply of the United States and the other nations of the free world. During 1939 this country produced over 3.6 million barrels daily of crude oil and related products permitting, after satisfying domestic requirements, a net export of some 350,000 barrels a day. Beginning with 1948 the United States has been a net importer of oil, and during the first half of 1952, when production, at 6.7 million barrels daily, was over 85 per cent higher than in 1939, the net imports of the United States amounted to some 500,000 barrels daily.
The most recent studies of the future development of the U. S. oil industry indicate that this trend toward an ever growing importance of foreign oil in the U. S. supply pattern will not only continue but is likely to be greatly reinforced. According to estimates of the President's Materials Policy Commission [PMPC], this country, by 1975, will produce 11.2 million barrels daily of crude oil and related fuels, including shale oil and other synthetics. Its requirements will be as much as 13.7 million barrels daily, necessitating net imports of 2.5 million barrels a day. As a result it is likely that the United States, which has in the past obtained the bulk of its imports from the Caribbean area, will in the future absorb not only the total surplus production in the other countries of the Western Hemisphere but will also require large supplemental quantities of crude oil from the enormously rich fields of the Middle East. Similarly the free countries in the Eastern Hemisphere, which procured a large portion of their oil needs before World War II from the United States and the Caribbean, import now over two-thirds of their greatly increased requirements from the Middle East and less than one-quarter from the Western Hemisphere.
This change in the supply position of the United States and free world is based on a fundamental shift in the relative size of proven crude oil reserves in the United States and in foreign oil-producing countries. At the end of 1938 U. S. reserves, at 17.3 billion barrels, constituted 61 per cent of total free world reserves of 28.5 billion barrels. By the beginning of 1952 proven crude reserves in the United States, although they had risen to 27.5 billion barrels, represented only 29 percent of the reserves of the free nations, which had reached a total of 95.5 billion barrels. Foreign reserves, mostly located in the Middle East, had accordingly increased from 11.2 billion to 68 billion barrels. If the most recent estimates for Middle East oil reserves had been used, the latter figure would even be some 20 billion barrels higher.
Automatic Well Testing Using a Two-Phase Separator
Authors: Fransen Gary 
Published: December 2007

Abstract
The traditional methods of testing the production of oil wells have involved the task of separating the produced stream into its components; oil, water, and gas. However, development of an energy absorption device for measurement of oil/water mixtures in any ratio has eliminated the need for three-phase separation. This technology allows the use of a much simpler, less expensive and more accurate system: the two-phase well tester.
Reservoir Management of Light Oil Steamflood Pilot in the SOZ Fault Block, Elk Hills Field
Authors: Hong K. C. , Blunschi J. H. , Cease C. C. , Madison D. L. 
Published: December 2007

ABSTRACT
The light oil steamflood pilot in the SOZ Fault Block at the Elk Hills Field, Kern County, California, has been managed by a team of geologists and engineers. To assist the reservoir management efforts, a history-matched, large-scale reservoir model was developed. A simulation study with this model quantitatively assessed the performance decrease from well productivity damage and the lack of reservoir confinement. It further showed that waterflood would have been the process of choice for recovering oil from this type of reservoir. The study indicated that future recovery strategy should aim at the oil banks that have moved out of the pilot area during steam injection, and should include a means to pressurize the reservoir. This can best be accomplished by converting the pattern steamflood to a line-drive waterflood and drilling additional wells to capture the displaced oil. A recommendation based on these findings is currently being implemented in the field.
New Technique Provides Better Low-Density-Cement Evaluation
Authors: Harness P. E. , Sabins F. L. , Griffith J. E. 
Published: December 2007

ABSTRACT
Ultra-lightweight cements have been used throughout the industry for many years as a specialty cement for application in areas of weak formations. Typical lightweight slurries use hollow ceramic microspheres or nitrogen and other low specific gravity materials to maintain light slurry densities while providing good compressive strength development. The one problem with these systems has been the evaluation of the job via sonic tools. This paper will introduce a new technique to allow an accurate interpretation of a sonic cement evaluation and will be demonstrated from laboratory model studies.
Light cement evaluation studies show a statistical variance technique to be the preferred method of evaluation in its class. Standard methods of cement evaluation rely on the contrast in acoustic properties of materials behind pipe. The Cement Bond Log (CBL) acoustic amplitude is used to derive compressive strength. The ultrasonic tool uses acoustic impedance to derive compressive strength. However, in the process of lightening the cement slurry, the acoustic properties of the cement can approach the acoustic properties of a fluid. Modeled values were compared to measured values of various slurries from 16.4 lb/gal to 9.0 lb/gal, confirming the trend from high acoustic impedance contrast of a cement to a drilling fluid in the case of a 16.4 lb/gal slurry to a negative contrast in the case of a 9.0 lb/gal slurry.
Situations can arrive where drilling mud will be displaced by a cement slurry of the same density. Standard cement evaluation techniques would not be able to identify the cement in this case because of a lack of acoustic impedance contrast. Another technique is available for low-density cement evaluation that identifies the cement from the fluid behind pipe by quantifying the other statistical variance of the acoustic impedance measurement. It will be demonstrated that there is a difference in the impedance measurement statistically between a solid crystalline cement and fluid, even though the absolute values are the same.
Additional work will demonstrate the difference between designed lightweight cement with nitrogen and cement that has been subjected to gas migration.
New Technology Improves the Performance of Borate Fluids in Low-Temperature Zones of the Belridge Field
Authors: Laramay S. B. , Shelley R. F. , Hatcher W. B. 
Published: December 2007

ABSTRACT
In high pH, low temperature fracturing fluids, enzymes are not useful breakers because enzymes are not active in high pH solutions. When these types of fluids are used, oxidizing breakers are used in conjunction with activators to break water-based fracturing fluids. A delayed release oxidizing breaker which it's operable temperature range is between 70 – 125 °F has been developed. This breaker is useful in delaying the break of high pH, low temperature fracturing fluids. Improved fluid rheology in the applicable temperature range was also attainable with this product. Filter cake dissolution studies pointed to the usefulness of the delayed release product in cleaning filter cakes of borate fluids. This product will allow the breaker concentration to be increased over the amount of conventional breaker currently added. This will lead to improved fracture cleanup. Actual field trials made in a Belridge Field study suggested that improved performance of borate fluids in the low temperature zones was attainable. Using a borate fluid with the delayed release breaker added allowed more sand to be placed in the fracture and increased cumulative oil production.
A Study of the Base of Fresh Water in the Southern San Joaquin Basin, California
Authors: O'Bryan P. L. 
Published: December 2007

ABSTRACT
This paper presents a study done to determine the base of fresh water in the southern San Joaquin basin in California. Presented is a base of fresh water contour map for the study area as well as a Rwe versus Rw correlation for determining Rw from the SP which was developed for fresh waters found in the study area.