bluuebunny/crossref_metadata_2025_split huggingface dataset:
A Study of Bacteria-Influenced Scale Deposition
Authors: Reeves N. K. 
Published: December 2007

ABSTRACT
Scale deposition in perforations and tubular goods has been a problem for decades in the oil industry. Years have been spent in research and in somewhat futile attempts to solve this problem. Classic treatment is with a fluid, usually an acid, which is designed based on the mineralogical content of the scale. Complicating these efforts is the relationship of down-hole bacteria to scale deposition. The above mentioned treatments do not address the presence of bacteria. The ability of organisms to thrive in hostile environments is sometimes difficult to overcome and the number of biocides on the market today attests to this. The problems caused by these scale deposits have cost producers millions of dollars and have been known to change sweet oil to sour in whole fields. Also, much money has been spent for cathodic protection and other corrosion inhibition treatments when the major cause of tubular corrosion may have been biological activity.
Typical scale identification consists of determination of constituents by chemical means, X-ray or microscopic analysis, and acid solubility tests. This series of tests is necessary for the design of scale removal treatments, but does not account for the causes of scaling. Computer programs which determine the scaling tendency of waters give an insight into the cause of scaling. However, none of these tests can show the influence of biological activity. In order to provide a more thorough analysis of the cause of scaling, the use of epifluorescence microscopy has been added to the testing scheme. Bacterial cells from a scale and/or water are dyed and their fluorescence observed microscopically. The lack of fluorescence indicates no biological activity. The information gained from this microscopic technique is then used to modify removal treatments and to design treatments to help prevent further deposition.
This paper will discuss (1) epifluorescence as a scale testing technique, (2) well conditions that contribute to bacterial growth, (3) areas in the Rocky Mountains where bacterial scaling is prevalent, and (4) removal and inhibition treatments.
Rate-Cumulative Type Curves for Forecasting the Performance of Curtailed Wells
Authors: Lewis P. E. , Hoff J. G. 
Published: December 2007

Abstract
Most gas wells in the U.S. have not consistently produced at or near capacity in recent years due to persistent excess deliverability in the gas market. Seasonal or erratic production history can wreak havoc with traditional well performance forecasting techniques. Rate-time forecasting methods generally depend on the assumption of capacity production throughout the life of the well. Distortion caused by curtailment can be reduced somewhat by plotting rate vs. cumulative flowing time, but flowing time is not always available, and more importantly, distortion is still present on both the rate and time axes.
The fundamental problem with rate-time history matching is that stabilized production capacity is not a function of time, rather, it is a function of reservoir pressure which is a function of cumulative production.
History matching with rate-cumulative type curves presented here eliminates curtailment induced distortion on the cumulative (X) axis. The rate-cumulative approach is more accurate for "real world" situations where only production per period is available (e.g. Mcf/month). Unlike rate-time curves, the proper rate-cumulative curve match will always represent stabilized producing capacity, regardless of shut-in periods.
Other advantages are that rate-cumulative type curves allow the engineer to read forecast ultimate reserves for any given abandonment rate graphically from the match, stabilized deliverability may be easily forecast at any given cumulative production, and cumulative production is inherently smoothed data.
Dimensionless rate-cumulative type curves were generated by integrating rate-time type curves developed by Hale1 for fractured gas wells draining
an elliptical area. The original type curves were based on infinite conductivity fractures, but the technique can be extended to finite conductivity fractures.
Type Curves for Predicting Production Performance From Horizontal Wells in Low-Permeability Gas Reservoirs
Authors: Duda J. R. , Aminian K. 
Published: December 2007

Abstract
Type curves have been developed for horizontal wells producing from low permeability gas reservoirs. The general solutions are presented in terms of dimensionless cumulative production and dimensionless time and are grouped based on two other dimensionless variables, the wellbore radius and well length.
The type curves were developed using the solutions to flow problems, which were determined using a finite-difference reservoir model. This paper includes a detailed account of the methodology used and comparisons of supporting simulation results to other, general flow solutions that have been previously reported. Issues concerning the production performance of horizontal wells in anisotropic media are also discussed. The curves can be used to initially predict the performance of horizontal wells, thus avoiding the need for costly and time consuming computer simulation.
A Simulation Study of Horizontal, High-Angle, and Vertical Wells in Eastern Devonian Shale
Authors: Zammerilli A. M. 
Published: December 2007

Abstract
This study is a comparative evaluation of predicted gas production from horizontal, high-angle, and vertical wells in the tight, fractured Devonian shales of West Virginia. The optimal drilling method was determined by economic and production comparisons of simulation results from studies of unstimulated and stimulated wells of the following types: a single horizontal well, a single high-angle well, and up to four vertical wells. Infill drilling was compared to new-lease wells, and the effect of faulting on predicted gas production was studied. The study showed that new-lease horizontal drilling is the optimal method in West Virginia, and high-angle drilling results in a slight improvement over vertical drilling. Horizontal drilling showed as much as a 46 percent improvement in production performance over both vertical and high-angle drilling for new-lease wells. Economically, a single 2,000-ft (6.096 × 102 m) horizontal well revealed a ROR of 40 percent and payout of 1.6 years as compared to 11.2 percent, 4.9 years and 4.1 percent, 7.8 years for single new lease vertical and 60° high-angle wells, respectively.
Well Spacing Analysis By The Discounted Production Method
Authors: Dehn Bren C. , Stoy Thomas W. 
Published: December 2007

Publication Rights Reserved
This paper is to be presented at the 36th Annual Fall Meeting of the Society of Petroleum Engineers of AIME in Dallas, October 8–11, 1961, and is considered the property of the Society of Petroleum Engineers. Permission to publish is hereby restricted to an abstract of not more than 300 words, with no illustrations, unless the paper is specifically released to the press by the Editor of the Journal of Petroleum Technology or the Executive Secretary. Such abstract should contain conspicuous acknowledgment of where and by whom the paper is presented. Publication elsewhere after publication in the Journal of Petroleum Technology or Society of Petroleum Engineers Journal is granted on request, providing proper credit is given that publication and the original presentation of the paper.
Discussion of this paper is invited. Three copies of any discussion should be sent to the Society of Petroleum Engineers office. Such discussion may be presented at the above meeting and, with the paper, may be considered for publication in one of the two SPE magazines.

Abstract
The Discounted Production Method of analyzing well density is a means whereby the increase in the discounted net profit by acceleration of a reservoir's depletion can be calculated for each succeeding development well. With the generalized equation, the actual accelerated reserves, and hence the discounted net profit, can be computed for any contemplated development well, for any interest rate, for any type of declining or constant production, and for any initial and final production rate.
This method has utility in that, it is a quick means of attaining the correct answer as to the number of wells that a pool should have in order to be properly developed by present worth standards. It also affords a ready comparison of discounted net profit and discounted profitability from potential development investments in different pools.

Introduction
After the exploration phase has passed and an oil pool is considered to be well enough defined to enter its development era, the problem is, how many additional wells are necessary to deplete the reserves. Although an inherent and Important part of this period is assuring that a maximum amount of oil be recovered from the reservoir, proper drainage of the oil is not the only consideration of those concerned with the economics of a development program.
What then constitutes proper development? In the days prior to mineral conservation commissions, proper development might have consisted of merely drilling as many wells as there was room for on a particular tract of land, or it might have consisted of enough wells to deplete the reserves in a given period of time that was considered to be a standard reservoir life.
Parameter Accuracy Required for Real-Time Fracture Geometry Simulation
Authors: Elbel J. L. 
Published: December 2007

Abstract
A major goal in hydraulic fracturing research is to be able to determine the fracture geometry, based on measurements of the treatment parameters, during the actual performance of the treatment. The treatment parameters measured are injection rate, viscosity of fluid and bottom-hole treating pressure; and, of these, the last two are difficult to obtain accurately under normal treating conditions. This paper provides equations and graphs that indicate the effect that an error in each parameter will have on the real-time fracture length calculation. These can be used to determine the parameter accuracy required and also indicate when real-time simulation will be practical and on what parameter (viscosity or pressure) it should be based. In fracture geometry simulation, it is assumed that the magnitude of the parameters are known. A number of papers have shown the effect of various parameters on fracture length. However, the effect of an error of an individual parameter is dependent on its magnitude in relationship to the magnitude of the other parameters. This paper shows that the effect of an error of a parameter on the fracture length calculation is a function of treatment efficiency. Therefore, if the treatment efficiency can be assumed or determined from an injection test, the effect of an error on any parameter can be determined. Simple algebraic equations and plots are given showing the effects of errors in each parameter as well as the error in more than one parameter.
Boundary-Dominated Flow in Solution Gas-Drive Reservoirs
Authors: Camacho R. , Raghavan R. 
Published: December 2007

Abstract
In this work the performance of wells in solution gas-drive reservoirs during the boundary-dominated flow period is examined. Both constant wellbore pressure and constant oil rate production modes in closed systems are considered.
For the constant wellbore pressure production mode, the conditions under which procedures in the literature can be used to analyze data are discussed. Specifically, Arps's equations for performance prediction are examined and it is shown that predictions of future performance are strong functions of well spacing, well condition, and fluid properties. The parameters, b (the decline exponent) and di (the initial decline rate), in the Arps equations are expressed in terms of physical properties. The conditions under which these equations can be used are specified. An empirical procedure to predict production rates is also presented.
In the case of constant oil rate production, an expression to correlate the pressure distribution in the reservoir is presented. The correlating function permits us to extend the definition of pseudosteady- state flow to solution gas-drive systems. Its use also allows the simultaneous computation of average properties (pressure and saturation) during boundary-dominated flow from wellbore information.
North Sea Reservoir Simulation: Practical Considerations
Authors: Johnson H. A. 
Published: December 2007

Abstract
Digital numerical simulation has played an increasing role in planning, developing, and depleting oil and gas reservoirs in the past 25 years. Through simulation, alternative development options can be evaluated to optimize development decisions (ref 1).
Since all of the North Sea fields have been developed since the advent of numerical simulators, numerous North Sea examples of applying numerical simulation to select reservoir development options exist in the literature. Virtually every field has had some simulation studies leading to its development.
The technology advances in both high speed computers and simulation software allow today's petroleum engineer to construct models with an ever increasing degrees of definition and complexity. The proper consideration of the need for a simulation study, the complexity required and the ultimate use all must be considered before a cost effective study can be undertaken. It is all to easy to design a model which is more complex than is required (ref 2). However, the limitations of a simulation model must be considered. A full field model is only as reliable as the data quality which is input. The most efficient use of simulation requires careful consideration of the ultimate use of the model, which frequently is dependent on the stage of field development.
Approaches to Full Field Simulation
Authors: Barnes A. L. 
Published: December 2007

Abstract
This paper discusses the objectives of full field simulation and the important considerations in full field model development. Major ARCO fieldwide models are described to illustrate these considerations and show how the use of full field simulation has developed. It is concluded that the reservoir management plans and investment decisions are made around full field modeling. Also, reservoir simulation has become more routine as computer costs have dropped. The trend of faster and larger computers should continue, increasing their use in reservoir engineering in the future.
Finite Element Representation of Two-Phase Fluid Flow Through a Naturally Fractured Reservoir
Authors: Bhatia K. S. , Advani S. H. , Lee J. K. 
Published: December 2007

AbstractTwo phase fluid flow through a naturally-fractured reservoir is investigated. The naturally-fracturedreservoir is characterized by two superimposed continua, with the fluid flow coupled via a fluid exchange term. The Galerkin-Newton method is used to discretize and solve the coupled differential equations. Problems associated with the representation of wellbore and induced fractures are initially evaluated. Steady state as well as time-dependent fluid flow around a wellbore is examined. It is demonstrated that curved isoparametric elements in the vicinity of the well with rectangular elements in the remainder of the reservoir can be used to obtain accurate solutions. Eight noded elements yield improved accuracy over four noded elements for single phase fluid flow through a porous medium. These elements also realistically model the flow field near induced fractures, for both single and two phase fluid flow cases. Langmuir's theory is used to model the sorption phenomenon in naturally fractured reservoirs. A onedimensional model is used to demonstrate the proposed procedure for dual permeability representation of naturally fractured reservoirs. The rapid convergence of solutions reveal the effectiveness of the finite element method in reservoir simulations. However, additional research on the presented methodologies is necessary.
Application of Reservoir Simulation Models to a New Parallel Computing System
Authors: Mayer D. F. 
Published: December 2007

ABSTRACT
The Connection Machine, which uses over 65,000 processors in parallel, is a SIMD (Single Instruction Multiple Data) computer capable of computing large reservoir simulation models efficiently. Features of this computing system are ideally suited to finite-difference solutions where equivalent operations are performed on different data in the grid blocks. The Connection Machine hardware and software are described, the application to reservoir simulation discussed, the code for a simple example problem provided, and timing results for this problem tabulated.
Enhanced Drilling Softwares and Integrated Advisor Expert Systems
Authors: Fenoul R. G. 
Published: December 2007

ABSTRACT
This paper describes the evolution of scientific softwares applied to ELF AQUITAINE's drilling operations.
Starting from an historically scattered situation, it points out how strategic decisions taken by the company have led to the development of a framework.
This framework, called CALPIN, set up to receive and integrate scientific programs, is now operational. It contains numerous softwares, including expert systems which are useful for drilling planning on operational bases and also help decision-making, directly on the rigsite.
The development guidelines as well as the solutions adopted are described in detail. The modular structure of the development allows for easy maintenance of the system and favours its evolution. In particular, it is easy to integrate a new software in the framework. Open to the outside, CALPIN enables the user to be connected with nearby data bases and to process his own data files by means of independent data-processing tools.
Control Aspects of Drilling High Pressure Wells
Authors: Prieur J. M. 
Published: December 2007

Abstract
Shell Expro ("Shell U.K. Exploration & Production", operators in the U.K. North Sea on behalf of Shell and Esso) have recently reviewed equipment requirements for the control of kicks incurred while drilling high pressure wells. Based on a "worst case" of a well bore full of gas, deriving from a reservoir pressure of some 14,000 psi [97 MPa], analysis of existing well control equipment standards has indicated a requirement for enhancements. New equipment standards have been developed and implemented, which will in all circumstances permit the well to be controlled, and the influx to be safely circulated out. These new standards principally apply to equipment which was already installed, though this equipment has been modified where necessary. These new standards mainly affect the BOP's elastomers, the choke manifold and the casing design. In some instances, control procedures have also been modified to take into account those equipment limitations that cannot readily be overcome. The main procedure change is the establishment of a maximum allowable kill rate which is governed by the capacity of the gas handling equipment on surface. These revised equipment standards and procedures will enable to control a well kick without danger to personnel or to the installation and should engender the confidence of the rig personnel.
Common Carriage and the Gas Act
Authors: McKinnon J. 
Published: December 2007

Abstract
In terms of the Oil and Gas (Enterprise) Act it has been possible since 1982 for competitive activity in the gas supply business. By the time the Gas Act 1986 had come into force there had been no successful development in the market. By the end of 1987, fifteen months after the privatisation of the British Gas Corporation nothing had occurred in terms of competition to its successor British Gas plc. What had happened however was that by that time the Gas Consumers Council and a number of individual customers of British Gas (BG) had complained to the Office of Fair Trading not only about the prices being charged for gas but also that British Gas had been acting unfairly in this regard. At that point no mention was being made about the lack of competition to British Gas.
The Director General of the Office of Fair Trading took the view based on the material presented to him that British Gas had a case to answer and referred the matter to the Monopolies and Mergers Commission. At the time of this reference media commentators emphasised the points on pricing but ignored or failed to realise the significance of the words combined in the OFT reference which indicated that the question of competition should also be considered by MMC. Perhaps this was because no commentator believed that there was ever going to be gas to gas competition.
In December 1987 OFGAS published a Report which examined the area of gas to gas competition. The Report suggested reasons as to why there had been no competition to date and made proposals about the steps needed if there were ever to be competition to British Gas. There were those who expressed surprise that OFGAS should have become involved in this area. After all OFGAS was supposed to have been brought into existence to look after the interests of the 17 million or so tariff customers of British Gas. Consequently it was stated that OFGAS had no reason to become involved in this the most vital area of the industrial and commercial segments of the gas supply market.
Performance of Manual Eddy Current Inspection of Welds in Offshore Steel Structures.
Authors: Cumming R. 
Published: December 2007

Abstract
The inspection of protected welded steel structures for fatigue cracks during their service life creates a set of problems which can be minimised by the efficient use of eddy current NDT techniques.
The oil industry has been cautious to adopt the techniques until the reliability of the equipment, the profiency of the personnel and the validity of the procedures have been demonstrated.
During the last five years SSNDT has provided a total package of support, by training and certifying technicians, by measuring the performance of equipment, and by devising and checking procedures in conjunction with industrial partners, details of which will be presented.
Over the last 18 months an industrial sponsored project has measured the limits of performance of eddy current equipment. The project work has specialised in the application of manual eddy current equipment ou fatigued and coated welds where the performance of the technician is a major contributing factor to overall reliability.
A method has been devised to provide a framework for the comparison of alternative manufacturers equipment and the validity of the basic measurements.
The latest results of the project will be described and include the limit of attainable performance of the inspections and the procedures which have become industrial standards.