bluuebunny/crossref_metadata_2025_split huggingface dataset:
A New Approach to the Prediction of Gas Flow After Cementing
Authors: Rae P. , Wilkins D. , Free D. 
Published: December 2007

ABSTRACT
Gas migration after cementing is a well-known and costly problem and one which is extremely difficult to prevent. Its causes are fairly well understood and several commercial techniques are offered today to prevent it, with varying degrees of success. Despite this understanding of the phenomenon, few attempts has been made to examine the parameters which may be relevant to it and, thereby, try to predict the probability of gas migration for a given well. Evaluating this risk, on a well-by-well basis, would allow the engineer to match his job design to this risk level.
In this paper, we describe a new approach to the prediction of post-placement gas flow. Our method is based on the identification of four key factors which are considered fundamental to the occurrence of gas migration. By using these four factors, we attempt to quantify the contributions made by the formation and annular configuration, the fluid hydrostatics, mud removal, and slurry performance, respec-tively. The factors consider such well parameters as reservoir productive capacity, annular geometry, pore pressure, hydrostatic head, mud removal efficiency, cement hydration kinetics and fluid loss.
Analysis of field data from a wide variety of gas wells in the United States, Canada, Latin America, Europe, Africa, Middle East, and Far East, has allowed the calculation of semi-empirical relationships between the four factors. The wide range of field conditions, through which this method has been established permits its use in most real cases. Field examples are provided.
Investigation of Natural Gas Hydrates in Various Drilling Fluids
Authors: Lai D. T. , Dzialowski A. K. 
Published: December 2007

ABSTRACT
This paper presents laboratory-derived equilibrium temperature and pressure data for gas hydrates in drilling fluids. Data are included for lime, sea-water gyp, polymer and dispersed muds with varying salt concentrations, as well as several experimental fluids. Equilibrium curves to determine salt requirements in deep-water drilling muds also are included.
Land Drilling Contractor: Can We Afford To Survive?
Authors: Loy S. E. , Johnson G. P. 
Published: December 2007

ABSTRACT
The U.S. land drilling contractor is in a serious financial condition. A continuous surplus of rigs and services over the past 8 years has threatened his economical survival. Capital replacements, particularly drill strings, must somehow be financed. The capital needs and a method of financing is discussed.
The economic dilemma of the drilling contractor has caused an attrition of experienced personnel. As a result, the drilling contractor must seize the opportunity to move his organization from one that is industry-based to one that is information-based to provide quality services and minimize both labor and G&A requirements.
Economics of the U.S. Onshore Contract Drilling Industry
Authors: Holm D. W. 
Published: December 2007

ABSTRACT
The principle purpose of this paper is to evaluate the pricing procedures of the onshore contract drilling industry and the resulting effect on contractor practices.
This evaluation includes an example, with discussion, of the cost factors included in the rates used by drilling contractors who desire to exercise prudent operating and management practices.
The paper discusses the areas of prudent operating practices that are currently being neglected, as well as management deficiencies which are prevalent, and how these factors are contributing to the drilling industry's problems.
Probable reasons for these actions by drilling contractor management and/or their financial supporters are reviewed to provide additional insight.
The paper concludes with the potential outcome of the current industry situation and general recommended strategies for drilling industry management, financial supporters, and operators.
An Economic View of the Drilling Industry
Authors: Strong R. E. 
Published: December 2007

ABSTRACT
During the past few years there has been some confusion, outside the industry, concerning contractor profitability. A survey was undertaken during early 1988 to evaluate rig operating cost and contractor profit potential. Sufficient information was obtained from six contractors who operate over 130 rigs to develop a representative average daily bid base and operating cost. Data is presented which will show the average contractor is operating at least 20% below the break-even point at 70% utilization. Investment and utilization sensitivities are shown and how they affect the contractor's cash flow.
Semisubmersible Rig Modifications for Subsea Field Development
Authors: Hoppingarner J. B. , Bates T. R. 
Published: December 2007

ABSTRACT
Subsea development is becoming commonplace in the UK sector of the North Sea. Over 50% of all fields to be developed in the next ten years on the UK Continental Shelf will be developed subsea and tied back to existing facilities or floating production facilities. In order to facilitate the development of these subsea fields a number of semisubmersibles have been converted from exploration to development mode. These rig modifications have included top drive installation, improved solids control equipment and oil base mud handling facilities, special subsea tree handling equipment, semi-permanent production test facilities and addition of saturation diving equipment.
These modifications have enhanced project economics by accelerating the drilling and completion of subsea wells. Each modification is discussed in detail.
Amendment to Louisiana Statewide Order 29-B Suggested Modifications for Barium Criteria
Authors: Deuel L. E. , Freeman B. D. 
Published: December 2007

ABSTRACT
This study was conducted to address the problem of inconsistent barium (Ba) analyses and the need to de-fine an acceptable criteria level. The study provides both mechanistic and comparative data in support of suggested changes in the Amendment to Statewide Order 29-B.
Initial non-hazardous oilfield waste (NOW) studies, which served as the basis for Ba criteria, used 1979 ERA protocol for estimating total metal contents. Three published revisions have since been made by EPA concerning Test Methods for Evaluating Solid Wastes (SW-846, 1982; SW-846, 1984; and SW-846, 1986), Sample size was the principal difference reflected in the revised protocols; sample size decreasedover time.
Experiments were designed and conducted to provide a method for determining "true" total Ba for comparison to SW-846 protocol. Regression analyses comparing SW-846 Ba as the dependent variable and corresponding total Ba as the independent variable showed the data best fit a polynomial (Y = -3.29 x 10 b(X)Z + 0.43 (X) + 376) with a r2 = 86%. Multiple linear regression analyses showed SW-846 Ba levels a function of the matrix pH, salinity, oil & grease, and "true" total Ba content.
A metals fractionation by sequential chemical extrac-tion technique demonstrated that Ba remains in a solid phase (barite form), evenafter being circulated down hole and subjected to extreme heat and strongly alka-line reactions. Chemical distributions varied signi-ficantly in response to mixing NOW solids with native soil and subjecting mixtures to reducing (diminished oxygen tension) conditions. Total Ba and oxygen ten-sion (redox potential) were found to have the greatest affect on Ba activity.
Integrity and Trends in Current Drilling Contracts: Risk vs. Reward
Authors: Williams D. W. , Schaffner W. R. 
Published: December 2007

Abstract
The document which precedes the performance of work and governs the operator/contractor relationship from the outset is the drilling contract. It is desirable that the contract be structured in a manner commensurate with the respective role of the operator and the contractor and in a manner where the combined parties have parallel goals. Often too little emphasis is placed on the construction of a fair, equitable and comprehensive contract which will promote a positive working relationship. In many instances, work is undertaken with the operator and contractor in an adversarial mode resulting from a lack of communication during the contract negotiation. The trend in today's contracts seems to be toward the shifting of risks and away from the quality and value of the service provided.
Offshore Operators Committee Gulf of Mexico Spotting Fluid Survey
Authors: Ayers R. C. , O'Reilly J. E. , Henry L. R. 
Published: December 2007

ABSTRACT
In the fall of 1986, the Offshore Operators Committee conducted a survey on spotting fluid use by member companies operating in the Gulf of Mexico. The purpose of the survey was to compare diesel and mineral oil spotting fluids for effectiveness in freeing stuck drillpipe. The survey covered the years, 1983 - 1986. Operators were asked to specify the number of wells drilled with water base mud for each year covered by the survey (1983 - 1986) and to supply certain information on each stuck pipe event where an oil base spotting fluid was used. The results showed that the success rate for freeing stuck pipe with diesel pills was 51%, while the success rate with mineral oil pills was 33%.
Rig Performance Monitoring and Measurement: Can It Again Be Useful?
Authors: Cochrane J. E. 
Published: December 2007

ABSTRACT
During peak activity in onshore Arabian fields (1981-1983) workover rig performance was monitored and measured against performance targets. The results were used to significantly improve rig productivity and, when activity dramatically dropped, to aid in rig lay-down decisions.
The lessons learned during this period were valuable both to the operator and the contractors; they should again be applicable when rig activity reaches moderate levels.
Running and Handling of a Premium Connection on a Rig
Authors: Raney J. B. , Lamb J. F. 
Published: December 2007

ABSTRACT
Adequate control of field running procedures for premium connections has been a dilemma for users and thread manufacturers alike. Extensive studies were undertaken to develop improved field running procedures and to investigate factors considered to be major sources of field damage. The results of this work have led Mobil to develop a unique statistical approach using shoulder torque values to control field running procedures for premium connections.
Through the utilization of statistical control charts and a torque monitoring system, Mobil, as an operator, has been able to establish a high level of confidence in the performance of a premium shouldered connection (PSC) run into the well. The power of this statistical approach is that it provides a real time decision making tool on the rig during field make-up and a method for adjusting the qualification criteria due to changes in the rig environment.
A torque monitoring system is the rig site device used to qualify connection make-ups. Other factors affecting the connection make-up are minimized by properly utilizing accessory equipment (i.e. stabbing guides, alignment yokes, single joint weight compensator and calibrated make-up tongs) and by implementing controlled make-up procedures (i.e. proper cleaning and drying of the connection, doping practices and controlled make-up speed).
What Is the Condition of Your Downhole Tools and How Are They Being Repaired?
Authors: Brinegar D. W. 
Published: December 2007

ABSTRACT
Economic considerations have required many contractors and rental companies to repair and reuse downhole equipment that would have been discarded much sooner in previous years.
While the practice of striving to obtain the maximum life cycle for each piece of equipment should be encouraged, increased attention must be given to inspection and repair methods.
API Specifications detail mechanical properties and dimensions for the manufacture of new products. But the vast scope of repair of used equipment cannot always be covered by exacting procedures or specifications. Consequently, the repair and maintenance of used equipment is often left to the imagination and ingenuity of the user and/or the repair shop foreman. Successful repair may require the interpretation and blending of several specifications by competent machine shop personnel.
One of the objectives of this paper will be to review repair methods that are being used to increase the life of downhole tools. Particular attention will be paid to welding procedures.
New Developments in Short-, Medium-, and Long-Radius Lateral Drilling
Authors: Karlsson H. , Cobbley R. , Jaques G. E. 
Published: December 2007

ABSTRACT
While traditional definitions classify short-, medium- and long-radius lateral wells by angle build rates, the technology now employed to achieve those build rates suggests an industry definition which characterizes lateral wells not only in terms of wellbore geometry, but in engineering terms as well.
In proposing such a definition, this paper examines new developments in downhole technology, focusing on short- and medium-radius systems to show how choice of drilling hardware can determine the type of curve drilled, as well as how it is planned and completed.
New horizontal well-planning techniques developed in light of recent hardware improvements are also discussed, while technicaf innovations still in development are noted.
Field results of recent lateral wells present examples of problem-solving, since a detailed discussion of lateral applications exceeds the scope of this paper. Concluding remarks suggest areas for further development to improve economics and performance in lateral drilling.
Enchova Blowout: Record Relief Time
Authors: Maduro W. P. , Reynolds Jim 
Published: December 2007

ABSTRACT
On April 24 during workover operations on the Enchova Platform in the Campos Basin, one of the platform's 21 wells blew out and eventually ignited. Relying on state-of-the-art technology, Petrobras drilled two relief wells in 30 days time and successfully controlled the blowout.
The organization for this operation encompassed three project subteams: one on each of the two offshore semi-submersible platforms and one at the land-based control center. Each was equipped with directional software designed to facilitate rapid data analysis and determine required changes in key drilling parameters.
A steerable system incorporating measurement-while-drilling (MWD) with a slow-speed, high torque downhole motor was used throughout the entire course of both relief wells. A rate gyro and a downhole casing detection tool complemented this package. Using this combination, both relief wells safely passed through a network of 21 existing wellbores.
This article outlines the primary considerations used in organizing and managing this successful relief effort Factors in well programming are discussed in detail along with the attendent problem areas.
State-of-the-Art of In-Situ Combustion Modeling and Operations
Authors: Islam M. R. , Chakma A. , Farouq Ali S. M. 
Published: December 2007

ABSTRACT
In situ combustion continue to be an important oil recovery process. The applicability of in situ combustion to wide range of reservoirs, and the recent advances, show that this process has unique advantages (as well as disadvantages). This report analyzes existing numerical models developed in recent years. Also reviewed is the state-of-the-art of in situ combustion from the point of experimental modeling and some field operations.
A comparative evaluation of existing in situ combustion numerical models helped identifying shortcomings of each model and detect missing links. This helped in developing new ideals and draw attention to the areas which have been ignored largely in numerical simulation studies. A complete in situ combustion model description is presented and difficulties in implementing such a model are pointed out.
This paper discusses in detail various mechanisms involved in in situ combustion operations and points out shortcomings of present experimental techniques. Guidelines are provided for experiments to be conducted in order to provide data for an ideal in situ combustion simulator.
Miscible Displacement of Heavy West Sak Crude by Solvents in Slim Tube
Authors: Sharma A. K. , Patil S. L. , Kamath V. A. , Sharma G. D. 
Published: December 2007

ABSTRACT
In enriched gas drives, for correct interpretation of slim tube displacement (STD) tests and for determination of minimum miscibility pressure (MMP) or minimum enrichment (ME) required to achieve dynamic miscibility, it is extremely important to identify the correct mechanism of misciblity development. Traditional, pseudo-ternary diagram construction and limiting tie-line method or the criteria of very high (90-95% plus) ultimate oil recoveries or the criteria of breakover point in ultimate oil recovery versus pressure diagram in STD tests, used to determine MMP or ME are not always valid and can lead to solvents designed either too rich or too lean.
In this study, STD tests supported by equation-of-state (EOS) predictions were used to evaluate the ability of various solvents such as CO2, n-butane and various mixtures of Prudhoe Bay natural gas (PBG) and natural gas liquids (NGL), to miscibly displace heavy, asphaltic West Sak crude. Results indicate that for enriched gas drives, the development of dynamic miscibility occurs via simultaneous vaporizing and condensing mechanisms. The solvent minimum enrichments for this dual mechanism were obtained from the solvent-oil, pressure-composition isotherms, compositional path in multicontact test (MCT) calculations and the methane spike disappearance phenomena in STD tests and were compared to those determined by condensing type, pseudo-ternary diagram construction method.
STD test results indicate that the ultimate oil recoveries, even for first contact miscible (FCM) solvent were considerably lower due to asphaltene precipitation. Asphaltene tests were conducted for various solvent-West Sak crude mixtures to determine the amount of precipitation and it's effect on oil composition.
STD results and EOS predictions indicate that CO2 was unable to develop dynamic miscibility with West Sak crude at reservoir pressure and temperature conditions and the process mechanism for CO2 drive is simultaneous vaporizing-condensing drive.
Thermal EOR in Salt Dome Structures of the Gulf Coast, Saratoga Field, Hardin County, Texas
Authors: Pebdani F. N. , Kleb M. S. , Johnson G. P. 
Published: December 2007

ABSTRACT
Field tests of various thermal enhanced oil recovery processes in the thin reservoirs of the Saratoga field in southeast Texas are in progress. The primary objective is to evaluate recovery and economics for each of: dry in-situ air combustion, wet in-situ air combustion, and steamflooding, to determine the optimal process.
The Saratoga field is one of many piercement type saltdomes located along the U.S. Gulf Coast. The field contains numerous Miocene sandstone stringers, averaging 20 feet in thickness and ranging in depth from 150 to 1900 feet, from which approximately 17% of the original oil-in-place has been produced by primary methods. The reservoirs contain low to medium gravity (14-22 °API) crude, with moderate to high viscosity (100-1000 cp), which make secondary recovery by a process such as waterflooding highly unfavorable. Thermal recovery processes were initiated in this field in the early 1970's; eight fireflood projects have been completed, while four wet in-situ air combustion projects and one steamflood project are ongoing.
Evaluation of these projects will provide a basis for the application of the appropriate thermal recovery process in thin, shallow reservoirs, typical of the Gulf Coast.
Role of Foam, Non-Newtonian Flow, and Thermal Upgrading in Steam Injection
Authors: Kasraie M. , Farouq Ali S. M. 
Published: December 2007

ABSTRACT
Foam formation and flow, non-Newtonian behaviour, and thermal upgrading phenomena play a role in steam injection processes, which is still not clearly understood. This investigation addresses these effects in the context of steamflooding. The results are based upon a steam injection simulator, which was modified to account for foam, non-Newtonian oil viscosity, and thermal upgrading.
Steam-foam flow was represented by means of a shear-dependent mobility, which was also a function of pressure, temperature, foam quality, and flow velocity. The relative permeability to gas was also a function of surfactant concentration. Non-Newtonian flow behaviour was implemented in the conventional manner, making the apparent viscosity of oil a function of local shear rate. Thermal upgrading was represented as a permanent decrease in oil viscosity depending on the residence time and temperature. These effects were incorporated into a three-phase, three-dimensional, fully implicit steam simulator.
It was found that a steam foam led to an increase in oil production rate, compared to steam alone. However, the increase was small, since the foam acted to increase steam viscosity, although the blocking effect was present to a small extent. The oil production behaviour in the case of a non-Newtonian oil was superior to that for a Newtonian oil, because the apparent viscosity of oil decreased in the cold part of the reservoir. Thermal upgrading, on the other hand, was less effective in increasing oil recovery, because the oil viscosity decrease due to cracking, over and above that due to temperature, was small.
The Design of a Modern Steamflood in a Thick, Dipping, Heavy Oil Reservoir
Authors: Atkinson D. S. , Clayton C. A. , Baldwin J. O. , Smith R. C. 
Published: December 2007

ABSTRACT
Mobil has completed the design phase of a steamflood project in a thick, moderately dipping, unconsolidated heavy oil reservoir. The design takes advantage of the gravity drainage recovery mechanism in the thick reservoir, allowing vertical steam zone expansion with minimal steam breakthrough. This steamflood project is economic in the late 1980's period of low oil prices. The design was completed with an interdisciplinary teamwork approach using concurrent studies for expediency.

BACKGROUND
During 1987, Mobil undertook a scoping study of its U.S. heavy oil producing properties, looking for areas of high potential for the 1990's. Several successful cyclic steam operations were identified as having potential that could be exploited using modern steamflood technology. The scoping study showed that the subject project had a reserve potential on the order of tens of millions of barrels of oil. The study documented here was undertaken to better determine the potential of this project.
The Use of Insulated Tubulars in Thermal Projects
Authors: Kutzak A. R. , Gunn D. W. 
Published: December 2007

Abstract
Many enhanced oil recovery steam projects are underway in Canadian heavy oil properties. Various well completion designs are employed to optimize the recovery and overall economic performance of these projects. This paper discusses both economic and design considerations regarding the selection of insulated tubulars as well as operational experience in some Canadian heavy oil recovery operations.
Study of the Cyclical Performance of Berm Pump Motors
Authors: Lea J. F. , Durham M. O. 
Published: December 2007

ABSTRACT
Cyclic loads, such as eccentric pumping units, cause a varying torque on the driver. Determination of the most effective induction motor for the load is addressed. Ultra high slip motors as well as NEMA design motors are evaluated. Comparison of operating costs for the same load are presented.
Elimination of Liquid Loading in Low-Productivity Gas Wells
Authors: Neves T. R. , Brimhall R. M. 
Published: December 2007

ABSTRACT
Liquid buildup in the wellbore has long been recognized as being detrimental to flow from gas wells. This paper will discuss a programmed approach for analyzing liquid loading problems and for selecting the optimal artificial lift method to be used once a liquid loading problem occurs.
This paper discusses factors affecting methods to alleviate liquid loading problems and guidelines for selecting in advance the optimum method to be used when liquid loading occurs.