bluuebunny/crossref_metadata_2025_split huggingface dataset:
Drilling Performance Improvement Case Study - Lawit-A Development Drilling
Authors: Dong S.N. , Longwell H.J. 
Published: December 2007

Abstract
This paper will cover a drilling performance improvement case study of an Esso Production Malaysia Inc (EPMI) gas development drilling program in the South China Sea. A "fast-track" process to optimize drilling time and cost is discussed, which includes planning, critical path activity and time analysis, and implementation.
Rig time savings of 45 days were realized through implementation of the "fast-track" recommendations. The "fast-track" recommendations include performing activities outside critical path or simultaneously, enhancing operational efficiency, applying available technology and eliminating critical activities through risk management. These recommendations coupled with careful planning, close surveillance, effective supervision, and team work were implemented without compromising operational safety.
P. 319
Advances in Metering and Control Technology Improves Design and Execution of Foamed Cement Jobs
Authors: Judge Robert A. , Benge Glen 
Published: December 2007

Abstract
A renewed interest in utilizing foamed cement slurries in wells where conventional slurries pose difficulties has increased the need for equipment capable of accurately monitoring and reliably controlling the necessary additives. These additives typically include nitrogen and a foaming agent. The goal is to have a completely automated control technology for the liquid additives and nitrogen. A fully automated system will also incorporate a cement mixing unit with automatic density control, with the additives metered in proportion to the base slurry rate. Proper pumping equipment selection is essential, but it is the flow monitoring technology selected that ultimately determines the accuracy of the additives. While process control technology for liquid additives is well established, metering and control technologies for automating nitrogen addition are less mature, and are critical to the proper execution of a foamed cement job.
Prior knowledge of slurry designs for a particular drilling program allows suitable components to be selected for use in an automated system, ensuring properly generated foamed cement slurries. The corollary is also true - that knowledge of the limitations of the equipment used to generate the foamed cement can lead to optimization of slurry design. Software is generally used to generate the ideal rates for base cement slurry, nitrogen, and liquid additives to obtain an optimum foamed cement slurry for a particular well. It is important to know that a software-generated solution that combines equipment capabilities with slurry and well requirements is technically feasible.
This paper describes the equipment and methods used to monitor and control the nitrogen and liquid additives used in foamed cement slurries. Additionally, the limitations of the nitrogen pumping and metering equipment, and how these limitations affect foamed cement job design, are discussed. Techniques to modify job parameters based on equipment performance parameters are also discussed. Charts from field evaluations of the developed system are included.
P. 349
An Investigation into the Application of QRA in Casing Design
Authors: Adams A. J. , Glover S. B. 
Published: December 2007

Abstract
The paper describes a major joint industry project undertaken to develop risk-calibrated design criteria for well casings and tubings. Supported by eighteen oil companies and two regulatory bodies, it included assessment of target safety levels; collection of historical load data and tubular resistance data; gas kick modelling and comparison with field test results; software enhancement; and calculation of risk-calibrated design criteria for the gas kick and tubing leak load cases.
The Development of Risk-Based Burst Design for Well Casing and Tubing
Authors: Tallin A. G. , Paslay P. R. , Onyewuenyi O. A. , Burres C. V. , Cernocky E. P. 
Published: December 2007

Abstract
This paper reports on the development of a risk-based burst design method. A criterion is developed so that ductile materials can be identified. The results for an experimental and analytical burst pressure study are combined with a large body of data for tubular dimensions and material properties. Statistical measures were obtained for all the data and a reliability study was performed on the design equations developed. This reliability study investigated: The relationships between probability of failure the design factor used in the design.The relationship between material grade and the probability of failure.The effect of axial tension on the probability of failure.The effect of flaw frequency on the probability of failure of a well string.The effect of D/T ratio on failure probability.
The methods developed can be used to estimate the probability of failure for well casing and tubing under any given combination of pressure and axial loads.
Burst Pressure Prediction of Thin-Walled, Ductile Tubulars Subjected to Axial Load
Authors: Paslay P. R. , Cernocky E. P. , Wink R. 
Published: December 2007

Abstract
This study was undertaken to support the development of a Quantitative Risk Analysis (QRA) for tubulars. The QRA required a burst model that was relatively accurate compared to the normal burst models used in conventional design.
Conventional work-hardening plasticity theory was used to establish a computer program for the prediction of the burst pressure of a thin-walled tubular. The tubular material was assumed to be ductile and the burst phenomenon caused by plastic instability. Dimensions of the tubular, the constant, external, axial load, Poisson's ratio, and a stress–strain curve for the material are the required input data for the program.
In order to verify the predictions of the computer program, twenty-two full-scale bursts tests were performed. The test specimens had capped ends with five of the specimens having an external, axial load applied in addition to the pressure loading. A stress–strain curve was measured for each tubular used for the test specimens so that the computer program mentioned above could predict the burst pressure.
Agreement between the predicted and measured burst pressures was excellent. The standard deviation of the ratio of predicted to measured burst pressure for the twenty-two tests was 0.04 with a mean value of 1.04. The program was then run extensively with all of the stress–strain curves to provide data for the development of an elementary equation which predicts burst pressure in the presence of an axial load. The resulting equation is surprisingly accurate so the program was modified using the same theoretical basis to allow different load paths to be investigated. By this means the burst load dependence on load path was established and shown to be rather small.
Finally, the elementary equation predictions were compared to the API Internal Yield Pressure Equation which is sometimes used for burst pressure predictions. The comparison of the API equation predictions to the elementary equation predictions shows that the discrepancies can be significant depending on (1) the ratio of the ultimate strength to the yield point and (2) the diameter to wall thickness ratio. The first discrepancy occurs because the API equation is based on yield point and the elementary equation is based on ultimate strength. The second discrepancy occurs because the API equation is based on outer diameter, while the elementary equation is based on mean diameter.
Accounting for Flaws in the Burst Strength of OCTG
Authors: Stewart G. , Klever F. J. 
Published: December 2007

ABSTRACT
The quantification of risk using reliability based procedures offers significant safety-related and cost benefits. In order to progress this methodology for design of wells, accurate capacity prediction models for OCTG and associated statistical data for the model parameters are required. In this paper, we focus (a) on the development of a predictive model for burst failure of OCTG with naturally occurring crack-like flaws and (b) on constructing probability distributions of crack depth based on estimated mill rejection rates and inspection quality.
Limit load models and ductile fracture mechanics techniques are employed to identify the governing failure mechanism and a simple unified model is proposed for burst capacity. This model is supported by finite element (F.E.) J-integral analyses and burst tests on P110 and Q125 tubes with artificial axial part-through cracks.
Experience Transfer from Operational Environments to Installation Design: Why, How and What?
Authors: Pagenhart A. , Buset H. , Throndsen T. I. 
Published: December 2007

Abstract
Experience transfer of practical, technical information concerning working environment, work efficiency and equipment functionality from operations to development projects is a good investment. A variety of methods used for collecting relevant experience are discussed. Criteria for prioritizing the wealth of generated experience data include an evaluation of frequency and consequences. Experience transfer plays a major role in a systematic approach to achieving the zero mindset goal. Cooperation on an intercorporate, international level is vital to continual improvement of the experience transfer process.
Case History of Oil Well Performance Monitoring and Production Optimization in the Eldfisk and Ekofisk Fields, Norwegian North Sea
Authors: Wade J. M. , Hough E. V. , Harrington T. R. , Valdai J. , Pedersen S. H. 
Published: December 2007

Abstract
This case history reviews the systematic well performance monitoring procedures developed and implemented for the Eldfisk and Ekofisk Fields in the Norwegian North Sea. Examples of production optimization projects implemented as a result of the performance monitoring system are presented. Changes in well performance due to acid washes, acid fracture restimulations, perforation additions and tubing changeouts are illustrated in the examples presented.
Comparison of Plate Separator, Centrifuge and Hydrocyclone
Authors: van den Broek Wim M. G. T. , Plat Robert , van der Zande Mark J. 
Published: December 2007

Abstract
Frequently oil is produced while, simultaneously, large amounts of water are produced as well. Under these circumstances it is important to have compact and efficient deoiling equipment at one's disposal. After some remarks on other de-oiling methods, the attention in this paper is focused on three separation techniques: plate separation, centrifugation and the use of hydrocyclones. The working principles are described and subsequently typical data on separation efficiency, geometry of the separator section, separator volume and critical oil-droplet diameter are derived or given. Analysis of these data shows, that the ranking with respect to performance of the three separator types is: centrifuge, hydrocyclone, plate separator. In the last section of the paper attention is given to some recent developments concerning centrifugation and the use of hydrocyclones.
Modelling Porosity Distribution in the A'nan Oilfield: Use of Geological Quantification, Neural Networks and Geostatistics
Authors: Wang L. , Wong P. M. , Shibli S. A. R. 
Published: December 2007

Abstract
A'nan Oilfield is located in the northeast of the Erlian Basin in north China. The porosity distribution of the oil-bearing stratum is primarily controlled by complex distribution patterns of sedimentary lithofacies and diagenetic facies. This paper describes a methodology to provide a porosity model for the A'nan Oilfield using limited well porosity data, with the incorporation of the conceptual reservoir architecture. Neural network residual kriging or simulation (NNRK or NNRS) is employed to do tackle the problem. The integrated technique is developed based on a combined use of radial basis function (RBF) neural networks and geostatistics. It has the flexibility of neural networks in handling high-dimensional data, the exactitude property of kriging and the ability to perform stochastic simulation via the use of kriging variance. The results of this study show that the integrated technique provides a realistic description of porosity honouring both the well data and the conceptual framework of the geological interpretations. The technique is fast, straightforward and does not require any tedious cross-correlation modelling. It is of great benefit to reservoir geologists and engineers.
Recovery and Utilization of Methane from Solid Waste Landfills
Authors: Frantz J. H. , Wood Randy M. , Sawyer Walter K. , Delozier Denise L. 
Published: December 2007

Abstract
This paper will discuss new developments in recovery and utilization of methane from solid waste landfill projects in the United States. Landfills produce methane and CO2 gas (LFG) at 550 BTU/scf due to decomposition of biodegradable waste. The LFG recovery industry started in California in the 1970's and has continued to expand. During the 1970's and 1980's, LFG was used primarily as an energy source for direct onsite use such as boilers, electric generation, and co-generation. In the 1990's, many landfills began investigating upgrading LFG to pipeline quality, high BTU gas. LFG can be upgraded commercially to pipeline standards by removing the CO2 using adsorption, membrane separation, or cryogenic processes. This paper will review the historical uses of LFG, but focuses on the more recent efforts to process and upgrade LFG to high BTU, pipeline quality gas. Several case histories will be presented showing historical landfill gas rates, gas rate history matches using LFG reservoir models, and performance forecasts for future LFG rates. We will also discuss a methodology to develop a more robust simulation model to estimate landfill gas production.
Drilling and Completing a High-Angle Well With Coiled Tubing Technology
Authors: Samsonsen B. , Jacobsen B.G. , Skagestad T. , Kerr S. 
Published: December 2007

Abstract
In many cases the casing exit point of a CTD sidetrack may have to be established below the cap rock to avoid high pore pressures and thus excessive mud weights. If the target is attic oil updip from the mother well, it may become necessary to drill a tangent section with very high inclination.
In the case of A-19A on Gullfaks field a tangent section with 125 degrees inclination had to be drilled with the TD ten meters shallower than the casing window. The challenging wellpath was successfully drilled and is likely to increase the number of achievable targets for CTD in the Gullfaks field.
Focus in the planning phase was centered on friction and forces available and thorough simulations were performed by the contracting company. The conclusion was that the well could be drilled if the friction factor in open hole was no more than 0,4. The experience from first CTD sidetrack in this field was that the friction factor in open hole was less than 0,4 when tripping. However, differential sticking seriously impeded weight transfer while drilling.
A solids free drilling fluid was regarded as the best choice for improving weight transfer. No problems were observed due to differential sticking. Priority was also aimed at investing the necessary time for frequent wiper trips to enhance hole cleaning.
The planning and observations of the operational challenges encompassed during this CTD operation are discussed further in the contents of this paper.
P. 81
Goldsmith San Andres Unit CO2 Pilot - Design, Implementation, and Early Performance
Authors: Jasek D.E. , Frank J.R. , Mathis L.S. , Smith D.J. 
Published: December 2007

Abstract
This paper describes the evaluation, design, implementation, and operation of a large miscible CO2 tertiary pilot in the Goldsmith San Andres Unit (GSAU), Ector County, Texas.
The pilot consists of nine inverted (injector-centered) 5-spot patterns covering approximately 320 acres and is located in a mature area of the field where the majority of the wells had been plugged due to high water cuts. The pilot location was selected based on geology and reservoir performance during waterflood. A CO2 pilot was chosen, rather than full- field implementation, to investigate uncertainties associated with the CO2 target oil saturation, the feasibility of re-entering abandoned wellbores, and overall CO2 flood performance. CO2 injection in the pilot commenced in December of 1996.
The project benefited from available technology on CO2 flooding and particularly from information on other San Andres CO2 floods. The paper summarizes the methods used in the early project evaluation/design, data acquisition programs, reservoir simulation and CO2 flood predictions, and project implementation. The reservoir management plan, actual performance to date, and future potential are also discussed.
The process used (methodology and technical analysis) to evaluate and design the GSAU CO2 pilot are applicable to other potential Permian Basin CO2 floods.
P. 23
Vertical-Horizontal Wells For Depletion And Sweep
Authors: Muraikhi A.J. , Pham T.R. , Liu J.S. , Khatib M.R. , Muhaish A.S. 
Published: December 2007

Abstract
This paper discusses a completion scheme currently being applied in a thick, large, elongated carbonate anticline Middle-East oil reservoir. The new well completion calls for a combination of an open hole horizontal section penetrating the top 10 feet of the reservoir and a cased or un-disturbed vertical segment through a thick formation. The horizontal section will be used for producing and the vertical segment will be used for monitoring purposes (Figure-1). The cased vertical segment will allow undisturbed monitoring of the sweep in the area below the horizontal section, especially in areas of high heterogeneity. The horizontal application proved to be useful both in terms of economics and sweep with supported reservoir simulation results and some actual field data performance. Pilot wells have been drilled and completed and early assessment has been encouraging.
P. 123
Practical Methods Employed in Determining Permeability Anisotropy for Optimization of a Planned Waterflood of the Elfisk Field
Authors: Wade J.M. , Hough E.V. , Pedersen S.H. 
Published: December 2007

Abstract
This paper presents the various techniques and measurements undertaken to determine both the magnitude and direction of horizontal stress anisotropy present in the Eldfisk Field in preparation for a planned waterflood. Results from field measurements of in situ stress obtained from a vertical pilot hole designed specifically for gathering stress data reveal a highly an isotropic state of stress, with a maximum horizontal in situ stress oriented approximately 47 from grid North. These measurements include stress orientations measured from an elastic strain recovery (ASR) tests on core, oriented acoustic log data and 2 micro-frac tests with pre- and post fracture imaging log runs. Micro-fracture tests yield values of 5218 psi to 5326 psi for the minimum horizontal stress and 6904 psi to 7154 psi for the maximum horizontal stress. This represents a relatively large stress anisotropy which, in turn, could result in a sizeable permeability anisotropy. A numerical simulation study was conducted to investigate the impact of horizontal permeability an isotropy and completion strategy on hydrocarbon recovery. The results of this sensitivity study show that the optimum completion strategy consists of suitably staggered perforation schemes in the injection and producing wells.
P. 49
Model-Based Sticking Risk Assessment for Wireline Formation Testing Tools in the U.S. Gulf Coast
Authors: Underhill W.B. , Moore L. , Meeten G.H. 
Published: December 2007

Abstract
A model is developed to characterize wireline formation tester sticking from quantitative analyses of the most prevalent sticking modes. An appropriate description of differential pressure sticking mechanics for stationary logging tools and cables forms the foundation of the model, and a supplemental formulation provides a quantitative relationship for key-seat development based on borehole and tool parameters. The results of the analysis are converted into a sticking probability formula that allows quantitative risk assessment at the job planning stage. The primary form of the model uses mud cake parameters derived from a wellsite evaluation device, but an alternative formulation utilizes laboratory and field measurements of mudcake properties and only requires conventionally available parameters for risk assessment. The model is calibrated and tested by application to a database of 664 formation testing jobs in the Gulf Coast area. The resulting strong correlation between calculated sticking probability and actual fishing frequency illustrates the power of a model-based approach to risk assessment. In contrast to most statistically based approaches, it is possible to incorporate a large number of relevant parameters and quantitatively examine risk levels as adjustments are made. Direct measurement of mudcake properties at the wellsite will further enhance the risk assessment accuracy.
P. 79
A New Method for Analysis of Long-Term Pressure History
Authors: Gilly Patrick , Horne Roland N. 
Published: December 2007

Abstract
This study presents a new way to integrate flow rate history and pressure history data in well-test analysis. The method used is an extension of the deconvolution principle to a chosen period of time before the well-test. It is based on the recovery of missing parts of the pressure history by taking into account the flow rate history and the available sections of measured pressure history. The method has the advantage of working without making any assumption about the reservoir by using the data itself to define the "model". A real example with 71 pressure points and 70 corresponding flow rate points shows how it is possible to recover the first 20 pressure points correctly considering that only the flow rate history and the last 51 pressure points are known.
The main purpose of this procedure is to have an alternative to treat the problem of flow rate variations both before and during the well-test. In such a case, neither the deconvolution (only applicable for flow rate variations during the well-test, when flow rate and pressure are both known), nor the multirate superposition plots (too constraining on the shape of the flow rate history and on the late time reservoir behavior) can be applied properly.
In addition, the principle of the method enables us to extend its use to the analysis of well-tests with pressure recording errors or missing pressure recording. Examples show that it is possible to make a good analysis of a well-test with missing pressure regions when current methods give only parts of the information.
P. 91^
Combined Production Logging, Transient Testing, and Well-Performance Analysis
Authors: Kabir C.S. , Hoadley S.F. , Al-Dashti Q. , Kamal D. , Hasan A.R. , Lin D. 
Published: December 2007

Abstract
This study presents an approach to exploit full potentials of a production logging run. In the proposed methodology, we seek layer flow contributions, reservoir parameter estimation, and well-performance optimization, in one logging operation. In particular, we match the entire wellbore pressure, temperature, and density profiles using a fully transient wellbore/reservoir simulator.
In the proposed approach, perturbations can be created either from static or dynamic well condition. New formulations for these initial conditions for multirate tests with non-Darcy skin are presented. Field examples illustrate the notion presented in this work.
P. 107