bluuebunny/crossref_metadata_2025_split huggingface dataset:
Practical Evaluation of Rock-Bit Wear During Drilling
Authors: Faÿ Hubert 
Published: December 2007

Summary
One key factor in minimizing drilling costs is understanding rock-bit behavior, particularly the bit-tooth wear, at the well bottom. This paper describes a method that gives information about bit-tooth wear during drilling. The basic concept requires the following torque equation that is a function of weight on bit (WOB), W: TOB=uW + vW2. This equation is determined from measurement-while-drilling (MWD) data, and knowledge of v provides the bit-wear state, given the close correlation between these two parameters. Laboratory tests and field results have confirmed the validity of the concept quantitatively. In today's harsh economic environment, field applications of the method should lead to more-accurate decisions about when to pull out bits and, thus, should reduce drilling costs.
An Environmentally Safe Water-Based Alternative to Oil Muds
Authors: Enright Dorothy P. , Dye William M. , Smith Martin F. 
Published: December 2007

Summary
A mechanism describing the onset of bit balling is given. On the basis of this mechanism, a new copolymer/polypropylene glycol (COP/PPG) water-based drilling fluid was developed. The properties of this fluid are described, and field test comparisons are made with water- and oil-based fluids
Cumulative Bioluminescence - A Potential Rapid Test of Drilling Fluid Toxicity: Development Study
Authors: Wojtanowicz A. K. , Shane B. S. , Greenlaw P. N. , Stiffey A. V. 
Published: December 2007

Summary
A new rapid test of drilling fluid toxicity is based on the spontaneous bioluminescence of Pyrocystis lunula, an easy-to- culture alga that vigorously responds to shear stress (mixing) by emitting a sharp burst of light. In contrast to other bioluminescence methods, a cumulative flux of light is measured with a photomultiplier that eliminates the effect of exposure time on test results. Light quenching, caused by the presence of a toxicant, results in the dose/response relationship (DSR) typical for the enzymatic reaction kinetics. The Michaelis-Menten (dissociation) constant is used as a direct measure of toxicity. The evaluation study involved multiple experiments with 60 samples of drilling fluids from the U.S. gulf coast, as well as such typical toxicants as diesel oil, mineral oil, and chrome lignosulfonate (CLS). The results of the test error analysis and comparisons with the Microtox and Mysid shrimp assays are reported.
The Transition from Domestic to International Oil Operations
Authors: McLean John G. 
Published: December 2007

Abstract
The general strategies that Continental Oil Co. has pursued in developing its exploration, production, refining, pursued in developing its exploration, production, refining, and marketing positions overseas in the face of strong, deeply-entrenched competition are discussed. Attention is given to the contributions that the so-called "newcomers" can make to the oil economies of the producing and consuming countries in which they operate. A commentary on the political, economic, and competitive outlook for oil operations in the Eastern Hemisphere is also given.

Introduction
Continental Oil Co. is only one of many American companies that have made the transition from domestic to international oil operations during recent years. When the history books for the third quarter of the 20th century are written, they will mark an era for American business-an era in which we became for the first time a nation of international industrialists, merchants, traders, and financiers.
In the oil industry alone, some 200 or more companies have gone outside the U. S. during the past 10 or 15 years. Continental's experience has not necessarily been representative of the entire group, or any substantial segment thereof, and I certainly would not want to present it as such. My purpose is to discuss solely our own experience and our own viewpoints. I shall try to answer four questions:
- Why are we trying to develop a strong position overseas?
- What policies are we following? position overseas?
- What policies are we following?
- What has been the impact of the newcomers like us on the oil business abroad?
- What do we see ahead?
The Genesis of Torsional Drillstring Vibrations
Authors: Brett J. F. 
Published: December 2007

Summary
Inherent drilling characteristics of polycrystalline diamond compact (PDC) bits alone can be sufficient to excite severe torsional drillstring vibrations. The work presented here augments previous findings that torsional vibrations can result from the drilling characteristics of the bit itself. Laboratory and field torsional measurements are compared with model results to show that the observed vibrations can be explained by a reduction in PDC bit torque as rotary speed increases. These torsional vibrations are important because they can cause drillpipe fatigue and may be severe enough to damage the bit. The model also is used to pinpoint possible solutions to the problem.
Some Effects of Pressure on Oil-Shale Retorting
Authors: Bae J.H. 
Published: December 2007

Abstract
A series of batch-type retorting experiments 930 degrees F were performed to investigate the effect of pressure and surrounding atmosphere on the retorting of oil shale. The experimental pressure ranged from atmospheric to 2,500 psig. pressure ranged from atmospheric to 2,500 psig. The sweeping gases used were N2, COe, H2O, NH3 and H2.
We found that high pressure reduces the oil yield significantly and produces a larger volume of light hydrocarbon gases. The crude shale oil obtained at high pressure has higher aromaticity and a lower pour point than the low pressure material. The sulfur pour point than the low pressure material. The sulfur and nitrogen content in shale oil does not change significantly with increasing pressure.
The effect of sweeping gas is usually small. In general, gases which decompose to yield H2 increase the oil yield at high pressure. At atmospheric pressure there is no effect. The high oil yield with H2, pressure there is no effect. The high oil yield with H2, more than 100 percent of the Fischer Assay, reported on "hydrotorting" experiments was not observed in this work.

Introduction
The in-situ retorting of oil shale has attracted much interest because it obviates the troublesome problem in surface retorting of mining, crushing and problem in surface retorting of mining, crushing and handling a large quantity of oil shale. The cost of these operations in the surface retorting process amounts to more than half the total production cost of shale oil. From an economic point of view, the recovery of shale oil by in-situ methods is highly desirable
At present in--situ retorting is accomplished by combustion or hot gas injection, following conventional hydraulic fracturing. Explosive fracturing also has been studied. While these methods of fracturing are promising, there is still much uncertainty associated with them. On the other hand, even if an adequate mass permeability could be created, the high pressures encountered at depths of several thousand feet where oil shale commonly existwould certainly affect the thermal decomposition of oil shale.
Thomas has experimentally simulated the effects of overburden pressure on the physical and mechanical properties of oil shale during underground retorting. Allred and Nielson studied the effect of pressure in reverse combustion on the yield and pressure in reverse combustion on the yield and quality of oil produced. These results are fragmentary and are applicable only to reverse combustion. Grant reported an oil yield of 35 to 40 percent of the Fischer Assay was obtained in a laboratory forward combustion experiment at 500 psig.
We decided to investigate the effect of pressure on oil shale retorting because so little information was available on subjects. We sought to determine me effects of fluid pressure and surrounding atmosphere on the quantity and quality of products obtained from retorting oil slide. Results of a series of batch-type retorting experiments are reported.
Large-Scale Properties for Flow Through a Stratified Medium: Various Approaches
Authors: Azita Ahmadi , Alain Labastie , Michel Quintard 
Published: December 2007

Summary
Published pseudofunction theories are compared with the large-scale averaging method in the quasistatic case by numerical simulations of two-phase flow in a stratified medium for different flow regimes. In some cases, the large-scale averaging gives results that are as satisfactory as those of more complicated and more expensive methods.
The Effect of Trapped Gas Saturation on Initial Oil-in-Place
Authors: Earlougher R.C. 
Published: December 2007

Summary
This paper investigates the need for an adjustment to volumetric calculations for initial oil in place and residual oil after waterflooding to account for in-situ trapped gas in many reservoirs.

Introduction
In 1962, I was coauthor of a paper that presented a porosity adjustment factor to improve volumetric calculations of oil recovery by waterflooding. The adjustment results in a reduction of calculated oil in place (OIP). The paper described in detail the determination of the adjustment factor but did not include a conclusive reason why the adjustment was needed.
Earlier publications described a laboratory procedure for the flood pot test on fresh core samples and reported that (1) rotary cores from many shallow reservoirs were not flushed by the drilling water, (2) waterflood oil recovery was determined directly from the flood, pot test, (3) total liquid saturation, Sl for many reservoirs seldom exceeded 95% PV after a water throughput in excess of 100% PV, and (4) volumetric calculations using Sl and porosity usually provided a much better fit with actual waterflood performance. Trapped free gas, Sgt, dispersed throughout the oil reservoir would provide a reason for the correction.
Table 1 illustrates the effect of the adjustment for a reservoir with 30 % Swi, an oil FVF of 1.2, and 9% Sgt. Trapped gas results in a reduction of initial stock-tank OIP, a greater reduction of residual oil after primary recovery, and an even larger percent reduction after waterflooding.
Four years ago, I had the new experience of finding 25 % N2 in the associated gas from an oil reservoir in the Morrow sand while consulting with Medallion Petroleum Inc. This finding reminded me of the use of the PV correction factor and the possibility of trapped gas. Consultation with many peers failed to find one who "knowingly" had encountered nitrogen in an oil reservoir. Further investigation led to a U.S. Bureau of Mines publication that included gas analyses for more than 13,000 oil and gas wells in the U.S. for the years 1917 through 1985. This publication suggests that free nitrogen in associated gas is not uncommon.
Field-Applied Computerized Tracking System: A Practical Approach to On-Site Quality Control
Authors: Purvis D. L. , Novotny R. J. , Carlson B. T. 
Published: December 2007

Summary
Automation and monitoring of modern hydraulic fracturing treatments demand a unique approach incorporating intelligent data acquisition and control equipment. This paper describes how a computerized system was applied to the task.
During a treatment, several operations are conducted concurrently. Concentrated gelling agents must be precisely proportioned with various additives to form a base gel. This base gel is then blended with sand, crosslinking agents, and breakers to form the slurry that is pumped into the formation. These operations dictate the metering, measuring, and controlling of many parameters simultaneously over several pieces of mobile equipment.
Multiple microprocessor-based control modules are used to perform this task. Each module interfaces with various transducers involved in a particular operation. The use and design of these control modules are outlined, as well as the transmission of information between the modules and the operations control computer. The hardware, software, and ergonomic aspects of the system are discussed. Finally, an additional engineering computer system is outlined, including its link to the central monitor. The presentation of information in a manner to facilitate quality control is discussed. Throughout this paper, emphasis is placed on the use of computer technology to simplify and improve data analysis and quality control.
PC-Based Quick__Look Graphical Postprocessing in Reservoir Simulation for Thermal Recovery
Authors: Baldwin J. O. , Wilcox G. G. 
Published: December 2007

Summary
In reservoir management, use of numerical reservoir simulators is playing an increasing role in developing planning, completion design, operating policies, and surveillance. Computer models, both in-house and commercial, are being used in EOR projects with detailed reservoir description for better understanding of the physics of multiphase fluid flow through porous media, history matching field and/or well performance, performing case sensitivities for variations in operating policy, and optimizing pattern and well spacing. For reservoir simulation to reach its full potential, it must become a tool that practicing reservoir engineers use with a high level of confidence. The goal of this paper is to demonstrate graphical postprocessing of reservoir simulation output as a key part in the overall results analysis process and as a critical link in assisting reservoir engineers with limited simulation experience to make competent decisions regarding reservoir development and operation.
A Laboratory Study of Gravity Drainage in Fractured Systems Under Miscible Conditions
Authors: Thompson J.L. , Mungan N. 
Published: December 2007

Abstract
Laboratory displacement tests were performed to study oil recovery efficiency by gravity drainage in fractured systems under miscible conditions. The porous media used were cylindrical Berea and Blue porous media used were cylindrical Berea and Blue jacket sandstone cores containing a number of well-defined, artificially formed, vertical and subvertical fractures. Butane and Soltrol 130 were the two miscible fluids used. The purpose of the study was to examine the influences of the displacement rate, fracture density, fracture orientation, fracture permeability, matrix permeability, crossflow, core length and connate permeability, crossflow, core length and connate water on the oil recovery.
It was found that displacement rate, matrix permeability and the subvertical fractures affected permeability and the subvertical fractures affected oil recovery most. The critical flow rate, based on the matrix permeability, was found to be a significant factor in the process. For displacement rates below the critical flow rate, the oil recovery efficiency appeared to be unaffected by the density of the subvertical fractures. At the high displacement rates, the fracture density becomes important, with the recovery being the most efficient in the core having the greatest number of the subvertical fractures. The magnitude of the fracture permeability, the fracture orientation, the core permeability, the fracture orientation, the core length and the connate water have little effect on the oil recovery efficiency.

Introduction
Gravity drainage under miscible conditions from relatively thick reservoirs can be a very efficient recovery process, especially at low flow rates where the gravity forces are dominant and, consequently, the adverse viscous fingers associated with the unfavorable viscosity ratio are minimized or eliminated. Such a process might involve injection of an LPG or some solvent bank at the crest and then driving the bank with dry gas. For some favorable combination of reservoir temperature, pressure and oil composition, there may be no need to inject any solvent bank, since enrichment of the dry gas by the light ends of the crude creates an in-situ solvent bank.
Slobod and Howlett have studied the effects of gravity segregation in vertical unconsolidated porous media under miscible conditions in the porous media under miscible conditions in the laboratory. The main variables in their study were the viscosity ratio, the density differences and the rate of flow. In this study, the objective was to find the influence of fractures on gravity drainage under miscible conditions. A greater number of related variables were also studied.
Optimization of Horizontal Well Matrix Treatments
Authors: Economides M. J. , Frick T. P. 
Published: December 2007

Summary
This paper presents an optimization method for the matrix stimulation of horizontal wells that may include the deliberate blanking of well segments. The lengths of these segments are balanced against the stimulation fluid volumetric coverage of the perforated segments. The stimulation and completion design is optimized through the use of the net present value (NPV) as an economic criterion.
Performance Analysis and Optimization of the Prudhoe Bay Miscible-Gas Project
Authors: McGuire P. L. , Stalkup F. I. 
Published: December 2007

Summary
Because EOR oil response at Prudhoe Bay has been difficult to measure directly, a number of different types of field measurements have been made to evaluate the miscible-flood displacement efficiency. These measurements include water- and solvent-injection profiles, logging data from an observation well, and single-well tracer test (SWTT) data. Despite ambiguity in these data, the measurements support the simulation and laboratory data and generally indicate that the Prudhoe Bay Miscible Gas Project (PBMGP) is performing well. The most useful EOR surveillance data have been the separator-gas-sample database, with ≈4,000 compositional analyses. Separator flash analysis and allocation programs use this database to infer EOR performance on the basis of produced solvent. Reservoir mechanisms that adversely affect the EOR process efficiency have been identified. The project has exceeded initial expectations in terms of solvent retained within the reservoir, which has favorable implications for solvent sweep efficiency. Procedures have been developed to use the field and simulation data to determine how the solvent should be allocated to the existing patterns and when the project should be expanded into new areas. These procedures are designed to maximize the value of the PBMGP.
Computerized Drilling Control
Authors: Young F.S. 
Published: December 2007

An on-site computer system to control bit weight and rotary speed has been developed and successfully installed on a South Louisiana well. Early field tests indicate that the system could be invaluable in reducing drilling costs.

Introduction
Previous laboratory and field experimentation has Previous laboratory and field experimentation has demonstrated the effect of several variables on drilling rate. These results have been incorporated into optimization theories for the purpose of reducing drilling cost.
Minimum-cost drilling theories rely on a combination of historical data and empirical prediction techniques for selecting optimum bit weight and rotary speed. Past solutions have required extensive use of computing equipment because of both the complexity of the mathematical formulations and the large number of parameters involved. Field attempts to apply these computed results have frequently failed because of the uncertainty of input data requirements.
Humble has developed an on-site computer system to control bit weight and rotary speed and thereby implement the concepts of minimum-cost drilling. This system can
perform short interval drilling rate tests for formation evaluation, use the results of these tests as input information to solve minimum-cost drilling formulas, and control bit weight and rotary speed in accordance with these computed solutions.
The purpose of this paper is to describe the computer control system and present results of initial field testing.

Theoretical Considerations
Minimum-cost drilling (MCD) requires a quantitative evaluation of the variables involved. Several forms of a basic mathematical model have been suggested. The relationships reported here form the basis for the solution programmed in this work. Four equations are used, expressing drilling rate, bit bearing wear, bit tooth wear, and cost.
A solution for minimum-cost drilling assuming constant bit weight and rotary speed over the entire bit life has been programmed for use in computing MCD schedules. This solution is subject to certain limiting assumptions such as those discussed by Graham et al.:
Drilling cost is the summation of bit cost, rotating cost, connection cost and hoisting cost. Diamond bits are excluded. Bit life is limited by either bearing failure or tooth wear, or by a combination of operational factors that make it cheaper to pull an incompletely consumed bit. Circulating hydraulics are adequate and do not limit drilling rate. Bit weight considerations exclude hole deviation. Drilling rate is a function of only bit weight, rotary speed, and degree of tooth dullness; that is, the effects of pressure, lithology, fluid property, hydraulics and drill string dynamics are ignored.
JPT
P. 483
Evaluation of Spotting Fluids in a Full-Scale Differential-Pressure Sticking Apparatus
Authors: Clark R. K. , Almquist S. G. 
Published: December 2007

Summary
A full-scale differential-pressure simulator was used to evaluate spotting fluids in the laboratory. Tests at elevated temperature and pressure identified a variety of unweighted and weighted, oil and nonoil fluids that are able to free differentially stuck pipe. Some low-toxicity, water-based spotting fluids are effective and acceptable substitutes for the traditional oil-based systems.