bluuebunny/crossref_metadata_2025_split huggingface dataset:
Safety as an Integrated Part of Platform Design
Authors: Harstad E. 
Published: December 2007

Abstract
Traditionally, risk, and safety analyses have been carried out as separate activities relative to the conceptual and detailed design development of offshore installations.
By continuous involvement from safety specialists, applying analytical tools as well as experience from former studies, it can be assured that –the correct decisions with respect to safety can be taken and incorporated without causing significant cost increase or schedule delays;–the need for additional compensating safety measures due to lack of inherent safe design is minimised;–the amount of redesign and reconstruction activities for safety reasons can be kept to a minimum.
This paper addresses how safety studies can be incorporated into the project organisation and project schedule, and the timing and type of qualitative and quantitative safety studies during the various phases of a project development.
Examples of application of risk and consequence studies as active design tools in recent developments are given.
Horizontal Well Evaluation in a Giant Oil-Rim in Unconsolidated Sand
Authors: Oosten R. K. V. , Cliff W. J. 
Published: December 2007

ABSTRACT
This paper concentrates on experience gained and techniques currently used in the evaluation of horizontal wells in an oil-rim located in the unconsolidated sands of the Rabi field, onshore Gabon, West Africa. Valuable experience leading to improved understanding has been obtained in the areas of:
– Open Hole Logging, including Fault detection and (Wireline) Formation testing – Production Logging on Coiled Tubing, including the use of Pulsed Neutron logs to identify gas and water in the horizontal section – Downhole pressure measurement for understanding horizontal well ‘dynamics’ and for production optimisation – Horizontal well test interpretation in a compartmentalised oil-rim.
Sizing an Electrical Submersible Pump in a Solution-Gas-Drive Horizontal Well
Authors: Kallas P. A. 
Published: December 2007

ABSTRACT
A model has been developed to optimize sizing the staging and brake horsepower requirements for an electrical sub-mersible pump (ESP) in a solution-gas-drive horizontal well. Three components are examined by the model, reservoir in-flow performance, casing and tubing outflow performance, and pump performance. Since severe gas slugging has been a characteristic of many horizontal wells, the gas slugging potential is monitored during the pressure traverse from where the fluid flows into the wellbore to the pump set depth. Flexibility for handling the gas at the pump intake has been included. The model can take into account the gas removed by a gas separator and the gas produced up the annulus. Actual data provided from norizontal wells producing with electrical submersible pumps has been used to verify the model's relative accuracy in sizing.
Multi-Rate Test Evaluation Using Field Cases
Authors: Pacheco E. , Da Prat G. 
Published: December 2007

Abstract
In this work, a brief summary is presented on the fundamental principles of multirate testing. The main objective is the analysis of several field cases where the technique has been successfully in the determination of drainage area reserves. The method of solution is presented for pressure transient analysis and involves the use of a numerical simulator in most of the cases for an optimum reservoir modeling. Examples of tests conducted in the Maracaibo Lake fields are presented. Based on several field cases, an efficient design of the multirate test in order to get the reservoir evaluation objectives was obtained. An extended flow rate period was added to the conventional way to conduct these tests resulting in a better reservoir description for the drainage area investigated. The results were used to determine the next development well in the field under study.
Porosity and Permeability from SEM Based Image Analysis of Core Material
Authors: Bonnie J. H. M. , Fens T. W. 
Published: December 2007

Abstract
Investigations into the relationship between the microstructure of reservoir rock and its petrophysical properties have made it possible to develop new procedures for deriving porosity and permeability data from digitised images of rock samples. The images of highly polished, resin-impregnated rock samples are recorded with an integrated scanning electron microscope/image analyser facility. Geometrical and topological features in the images have been quantified with the image analyser for 62 rock samples from 13 different reservoirs. Image-derived properties were compared with petrophysical properties as determined on corresponding core plugs using conventional analytical techniques.
The image-derived data pertain to a section through each sample and are therefore essentially two-dimensional. A number of quantities, such as porosity and surface-to-volume ratio, are determined from these data using stereological procedures. The subsequent analysis establishes a relation between image-derived quantities and plug-derived permeability.
The results obtained so far indicate that the image-derived porosity agrees with the core-plug-derived value to within 2.5 porosity per cent, while permeability is reproduced within a factor of 2.5. Deviations are ascribed partly to plug heterogeneities. The permeability relation has been tested on a challenging data set consisting of 16 additional samples, not in the above-mentioned learning set. The results show a major improvement over the conventional porosity-permeability cross-plot.
SIC - System for Identifying Contaminants in Drilling Fluids
Authors: Barragan R. V. , Aragao A. F. , Machado J. C. 
Published: December 2007

Abstract
Preventive treatments are the best method to avoid contamination. However, if it occurs, it is necessary to restore the original properties off drilling fluid by addition of chemicals after the contamination. The changes in the drilling fluids properties, determined by regular test at specified intervals, will indicate the type and degree of contamination and required treatment.
This paper presents a software which identifies various contaminants from the analysis of their properties during drilling operations.
A TURBO PASCAL program was developed using some artificial inteligence techniques. This program, named SIC (System for Identifying Contaminants), verifies, for each usual contaminant, the possibility of its degree of influence on each drilling fluid property.
Control of Erosion - Corrosion in Flowlines of Wells in Northern Monagas
Authors: Serrano J. , Peñalver J. 
Published: December 2007

Abstract
This paper presents the results of erosion-corrosion studies on 31 flowlines of wells in Northern Monagas, based on ultrasonic measurements of wall thickness of 4 1/2" diameter sections, extending from the wellhead standpipe to the anchor pile. These sections showed wear in the range of 12.5 to 35% with respect to nominal thickness of 11.12 mm and 8.55 mm, which correspond to critical erosion-corrosion rates of 3.7 to 12.88 mm/year and estimated remaining useful lifetime of 4 to 19 months before the onset of failure.
Subsequent inspections, which included cutting open the critical sections facilitated verification of the degree of wear which had taken place. From these results, a program was developed for the replacement of damaged short radius, 4" diameter, 45° elbows, by large radius, 6" diameter, 45° elbows and replacing the 4 1/2" diameter pipes by 6 5/8" pipe. These changes resulted in a decrease in the erosion-corrosion rate to approximately 0.26 mm/year and an increase in the estimated useful life of the most critical lines from one to as much as eigth years.
The results of this work also indicated that the equation Er = KVn (where Er is the erosion-corrosion rate, V is the flow velocity and n and k are constants) which was found by other workers to be applicable to erosion caused by aqueous References and illustrations at end of paper. slurries in laboratory studies, can also be used to describe the erosion-corrosion processes under actual operational conditions of producing wells.
Drilling Mud Solids Control and Waste Management
Authors: Bouse E. E. , Carrasquero J. E. 
Published: December 2007

Abstract
Several of the processes used to reduce the environmental impact of drilling are counter—productive. They can increase drilling cost and often worsen the waste disposal problem rather than solving or relieving it. Two-stage centrifugation is probably the worst of these processes. The trends toward total reliance on shale shakers for solids control, and the return of the liquid portion of hydroclone underflow to the system, in unweighted muds, are also very troublesome.
This paper reviews the importance of solids control and its relevance to waste management, discusses closed mud systems and other methods of handling drilling fluid waste, and reviews the proper design, installation, and monitoring of the solids removal system.
Dual Completions in EI Furrial Field
Authors: Mayol J. R. , Asuaje R. , Salazar A. 
Published: December 2007

Abstract
The "EL FURRIAL" field has an extent of 31250 acres, in which the original oil in place of medium API gravity oil is in the order of 4000×10 Bls. The main reserves are in the naricual formation. In this zone there are three reservoirs, in the following order: upper naricual, medium naricual and lower naricual, the production of these zones have been planned for the extraction of proportional volumes from each reservoir in order to optimize drainage while maintaining equilibrium of pressure and production in the reservoir. The configuration of the naricual formation establishes a favorable condition for dual completions.
In order to design the optimun dual completion to be run in the area, we conducted an engineering study taking into account the latest technology available worldwide on this type of completions. The experience gained by Lagoven running 176 dual completions for the past 30 years in Western Venezuela using double grip hydraulic dual packers. Proved to be very difficult to retrieve from the well-during the workover operation.
Based on these reasons, on march of 1988, we began a program to complete a well with two production strings consisting of 3-1/2"×3-l/2" (8,9 × 8,9 cm) using a dual flow assembly, instead of double grip hydraulic dual packers.
This reccomendation was applied successfully in the furrial No. 12 well; and until august 1991, we have run 17 dual completions in this field averaging a daily production of more than 200.000 BOPD of medium API gravity oil.
The objective of this paper is to present the experiences and results gained using this technique to complete in deep, high pressure and high temperature wells.
The Influence of Capillary Pressure when Determining Relative Permeability from Unsteady-State Corefloods
Authors: Savioli G. B. , Bidner M. S. , Grattoni C. A. 
Published: December 2007

ABSTRACT
An automatic history-matching algorithm has been developed to determine relative permeabilities and capillary pressure curves simultaneously from the production history of a displacement test of oil and water through a core. Relative permeability and capillary pressure curves are represented by power functions. Those representations contain some parameters which are found by minimizing an objective function. The objective function is formed by the sum of the square of the differences between experimentally measured and numerically simulated production data. The numerical simulator is an IMPES finite-difference program which models the one dimensional two-phase flow. The minimization is performed by a non-linear regression algorithm: the Quasi-Newton Approximation for the Least-Squares Problem (Broyden-Fletcher-Goldfarb-Shanno formulae).
The automatic history Bitching algorithm is applied to analyze the influence of capillary pressure on the determination of relative permeability curves. The algorithm is tested with simulated data and with actual experimental data.
Database consisting of simulated experiments with random errors are tested to demonstrate the feasibility of the method. Besides, they provide exact relative permeability curves for comparison purposes. In effect, results obtained by using simulated data show the convergence and uniqueness of the algorithm. But the main observation is that relative permeabilities estimates can be in error when capillary pressure terms are neglected.
Several sets of actual experimental data at inlet constant pressure are also tested. Convergent solutions are always found. Three different objective functions are applied. They are formed by oil rates, total fluid rates or a combination of both. The solution is dependent on the chosen objective function. Best adjustments are found by applying a combination of oil and total fluid rates, and including capillary pressure.
Fully Implicit Compositional Modelling of Gas Condensate and Volatile Oil Reservoirs
Authors: Gomes Hamilton P. , Corrêa Antonio Cláudio F. 
Published: December 2007

ABSTRACT
This work describes an isothermal and two-dimensional fully implicit compositonal model, which has been developed to the modelling of retrograde gas condensate and volatile oil reservoirs.
The model considers oil, gas and water phases, and may be used with either cartesian (x-y) or cylindrical (r-z) grids. Water has been considered to be immobile and slightly compressible, and water saturation is a function of pressure. Instantaneous thermodynamic equilibrium has also been considered, with no water dissolved in the hydrocarbon phases and no hydrocarbon dissolved in the water phase. Fluid-rock iteractions have not been considered.
Phase equilibrium and fluid properties have been computed by means of the Peng-Robinson6 equation of state. The adjustable coefficients of the equation of state have been previously determined by means of a comercial PVT simulator.
The resulting system of partial differential equations has been discretized by the finite difference method, yielding a non-linear system of algebraic equations. The one-point upwind scheme has been selected to compute the molar densities and the saturation dependent properties.
The Newton-Raphson method has been selected to solve the resulting non-linear numerical problem. The block penta-diagonal matrix has been solved by Gaussian elimination, which takes advantage of the matrix sparcity. The grid-block saturation pressures are updated at the end of each timestep.
Due to the problem complexity, the validation of the model has been provided to the steady-state flow case, which presents a known analytical solution for compositions and saturations.
Examples of application of the computer model to depletion process and well testing are presented.
Influence of Mass Transfer in Bottomhole Pressure and Afterflow Determination from Fluid Level Data
Authors: Pires José A. P. , Corrêa Antonio Cláudio F. 
Published: December 2007

Abstract
The Acoustic Well Sounding (AWS) method can be used for indirectly computing both bottomhole pressure (BHP) and rate of afterflow in pumping wells. This calculation uses fluid level and casinghead pressure data obtained during a a transient test. During pressure buildup tests, free gas goes back into solution as the pressure increases in the wellbore. This causes a reduction in both oil density and free gas flow rate. Mass transfer between the oil and gas phases has not been explicitly considered in the literature. This can be of significant influence for long shutin time. In this paper a method is proposed which accounts for the mass transfer between liquid and gas phases. A selected comparison example from the literature has been interpretated using both conventional and rate deconvolution analysis.
An Integrated Approach to the Design and Interpretation of Reservoir Tests and Well Productivity Analysis
Authors: Burgess K. A. , Pelissier-Combescure J. , Joseph J. 
Published: December 2007

AbstractOne important goal in reservoir testing is to determine the reservoir characteristics and the well's productivity. Measurements which can contribute to this goal include well logging, fluid sampling, pressure transient testing, and production profiling. A careful analysis of these measured data will provide adequate information for well evaluation. The purpose of this paper is to show how an integrated reservoir testing methodology in conjunction with a human engineered procedure on computer enhances the reservoir characterization and the evaluation of well performance.This integrated methodology includes concepts, which have been implemented in recent approaches to reservoir testing and NODAL* analysis. During the design phase of each test, sensitivity studies provide insights that facilitate adequate data gathering for valid interpretation, which can help minimize the cost of the test. During interpretation, the central issue is to identify a realistic reservoir model which reflects the transient pressure and rate behavior. Here significant use is made of the log-log plot of pressure change and its derivative with respect to superposition time. Systematic diagnosis of the log-log plot helps identify different flow regimes, while specialized plots and type curve analysis provide a basis for the estimation of reservoir parameters. Lastly, the computed results can be easily integrated into a NODAL analysis to study and evaluate the well's productivity.The examples presented illustrate the benefits of a systematic approach to reserovir test design and interpretation, and well productivity evaluation. The computer procedure also has the advantage of incorporating input data from several sources, including openhole logs and the Repeat Formation Tester (RFT*) tool.
A Study of Rheological Properties of Non-Newtonian Fluids and Settling Behavior of Ceramic Proppants Manufactured in Louisiana, USA.
Authors: Alcócer C. F. , Ghalambor A. , Sweet L. H. 
Published: December 2007

Summary
This paper presents the results of the study of the settling rate performed on C-P, C-L Proppants, and Sand for 16 and 20 mesh sizes.
The method of experimentation was Stoke's Method which is used for analysis; the Stoke's Law was not applied to the measurements. This is due to the fact that the Stoke's Law applies only to measurements of in newtonian fluids. The polymer (nonNewtonian fluid) used XCD is a shear thinning fluid with gel behavior and its viscosity is depended upon the fluid motion.
The test performed in a settling tube simulates static fluid condition. The results showed the effects of proppant density, diameter and size of particles, as described by Stoke's Law. The proppant C-P has 2.2 to 2.5 times the velocity of the proppant C-L. Proppants of size 16 mesh have 3.2 to 3.6 times the velocity of 20 mesh proppants. The first shows the effect of the density and the second illustrates the size or diameter effects, respectively.
Diffusivity Equation for Real Liquids with Gas in Solution
Authors: Lanfranchi E. 
Published: December 2007

ABSTRACT
A rather comprehensive theory has been developed to describe fluid flow phenomena in porous media. This theory, under the constraints of appropriate simplifying assumptions, ultimately leads to expressions which enable the petroleum engineer to characterize reservoir behaviour. In this context, one frequently treats some form of the diffusivity equation in conjunction with data obtained from well tests to arrive at specific reservoir parameters. For example, so-called pressure transient analysis can be used to arrive at estimates of the formation thickness permeability product, the storage capacity, the average reservoir pressure, etc. For liquid flow, the technique involves reducing the diffusivity equation to a form where pressure becomes the independent variable. This requires the assumptions that the liquid is both, ideal and slightly compressible.
In this work it has been developed an alternative approach which does not depend upon the assumptions cited above. An additional intent is to investigate the effects of these suppositions on computed pressure distributions in a one-dimensional system.
Utilization of Water Salinity as a Continuous Miscible Tracer in Waterflooding
Authors: Angeles R. Martínez 
Published: December 2007

ABSTRACT
An experimental simulation on the miscible displacement in fractured oil reservoir is presented. The theoretical and experimental studies are based on the ideas originally developed by Coats and Smith and recently modified by Perez-Cardenas in connection with miscible and immiscible displacements in heterogenous media which contain a double-porosity system. The proposed model considers that fluid displacement takes place through the fracture system by Convection-Dispersion process, while the matrix blocks exchange matter with the fractures mainly by hydrodynamic dispersion and molecular diffusion. To test the theory and experimental model, several displacements simulations were carried out with real field data. This paper describes application of two-dimensions simulations to miscible displacement during waterflooding operations. The first section describes a method of calculating the behavior of a water salinity tracer by use of an analytical solution for the Dispersion-Convection Equation. The second section of this work extends the analytical results in Berea sand cores. Finally, the last section covers the field simulation, thus the objective is to study the tracer evolution for frontal displacement simulation. Results are presented on calculations of salinity digital images for each evolution step at several pore volume injected and levels of mechanical dispersion-convection.
Reserves Nomenclature World-Wide: an Utopia?
Authors: Martinez A. R. 
Published: December 2007

Abstract
Everybody, everywhere acknowledges the need and usefulness of a simple, unassailable nomenclature for a hydrocarbons reserves system with world-wide approval; non-geological and non-engineering considerations, prominently of a commercial character, have prevented the acceptance of such a global scheme. Most relevant to the proper review of the awkward situation, is the prerequisite recognition of reserves as physical entities of L3 dimension.
Reserves are the quantities recoverable from the underground hydrocarbon deposits. No individually recommended scheme of reserves nomenclature seems to have the necessary persuasive power nor absolute imagination to develop into a universal classification; only, international organisations of undisputed prestige could submit a system capable of a general agreement, intelligible to economists, policymakers, politicians and laymen, while at the same time satisfying the professional needs of the petroleum scientists and technologists. The objective should be to incorporate existing definitions and nomenclatures, to those currently used in legislation and banking, or trade and custom. Particular positions of countries should be set aside, towards attainment of an international consensus. Then, a visionary utopian reality shall prevail, for a perfect technical order.
These devices be then made laws. Thomas More, Utopia, 344.
Heat Checking/Quench Cracking Tool Joints
Authors: Altermann J. A. , Smith T. B. 
Published: December 2007

ABSTRACT
Tool joints may be heated in service above the critical temperature of steel through the heat of friction. When this steel is quenched by the drilling mud, longitudinal cracks develop. These initially shallow cracks propagate rapidly. In boxes they lead to washouts near the makeup shoulders. In pins, some cases have lead to pin base failures and fishing jobs.
This drill string problem has plagued the oilfield for more than 40 years. In spite of this, many experienced drillers are unaware of its existence and have difficulty accepting the facts when they are first presented.
Heat checking/quench cracking of tool joints may occur when they are forced against the wall as they are rotated or pulled from the hole. This force or side thrust may result from an intentionally deviated well or from one which developed a severe dogleg.
The effects of severe in-hole heating has recently been observed on bottom hole assembly components used with top drive systems.