bluuebunny/crossref_metadata_2025_split huggingface dataset:
Statistical Forecast Models To Determine Retrograde Dew Pressure and C7+ Percentage of Gas Condensates on Basis of Production Test Data of Eastern Venezuelan Reservoirs
Authors: Marruffo Ilsis , Maita Jose , Him Jesus , Rojas Gonzalo 
Published: December 2007

Abstract
In this paper are presented correlations to determine the dew point pressure and C7+ content of gas condensate reservoirs, achieved from production parameters that we usually have in the field. To develop this correlations it were collected 146 PVT analysis informs of western Venezuela (Anaco) fields: San Joaquin: 42; Santa Rosa: 26; El Roble: 16; Guario: 4; Santa Ana: 3; El Toco: 3; Zapatos: 15; Mata-R: 15; Aguasay: 13; La Ceibita: 5; Carisito: 4. At the end it were finally used 106 to the final correlations.
The PVT tests results were validated through consistence tests: mathematical recombination and mass balance. After this steps an statistical analysis of the variables was done.
For this, statistical methods were used and they were focused on multiple no linear regressions.
At last the correlations accuracy were the following: dew point pressure showed 5.74 % of average error with a correlation coefficient of 0.82 based on 80 PVT's data, the first C7+ content correlation showed 9.59 % of average error with a correlation coefficient of 0.98 based on 81 PVT's data, the second C7+ content correlation showed 7.85 % of average error with a correlation coefficient of 0.99 based on 90 PVT's data.
The new Retrograde Dew Point correlation that was obtained improves the Nemeth and Kennedy (10) one that forecast dew point with 9.69 % of average error when it is applied on 54 Anaco's PVT analyses which had all the compositional information that it requires; with the new Anaco Dew Point Correlation the average error was 5 % for the same data. This news Anaco correlations allow to improve the characterization and exploitation plans of gas condensate reservoirs without PVT information.
Intelligent Automation for Intermittent-Gas-Lift Oil Wells
Authors: Correa Jose F , Santos Odair G , Inazumi Paulo C M 
Published: December 2007

Abstract
Intermittent gas lift is widely used in the PETROBRAS onshore petroleum fields. The intermittent gas injection in the annulus between the tubing and casing causes a gas lift valve to open. This gas lift valve is a pressure driven valve installed in the lower part of the tubing and controls the amount of gas injected at the bottom of a liquid column held inside the tubing. The injected gas becomes a big gas bubble that carries the liquid column up to the surface. The intermittent cycles are obtained by a motor-valve installed at the surface opening and closing at fixed time intervals (Time cycle – Tc) and remaining open during a fixed amount of time (Time injection – Ti). This work presents the concepts use in a firmware for Programmable logic Control (PLC) especially designed to optimize both Tc and Ti. Based on the tubing and casing pressure continuously acquired by a pair of electronic pressure transmitters (PT) and on artificial intelligence (AI) concepts such as neural nets and fuzzy logic, this firmware performs the pattern recognition of the casing and tubing pressure behavior, executes an algorithm implemented by the user and gives a diagnostic about the performance of the system. With the diagnostic and changing the values of Ti and Tc, the electronic device improves the system performance, reducing the gas consumption and increasing the liquid production. The electronic device is installed at the well site and send to the central office, by request, the data acquired from the well. At the central office, a PC computer with a modem performs a data pooling, well by well, and stores the acquired data in MS-Access type data base for further statistical and historical analysis.
MIC: Microbiologically Influenced Corrosion in Gas Transportation Pipelines
Authors: Raffa Duilio F. 
Published: December 2007

Abstract
The present article analyzes the intervening factors in the complex phenomenon of the Microbiologically Influenced Corrosion and its relative influences. Basing on this analysis, an information correlation methodology is proposed to establish a monitoring criteria, control and evaluation of associated risk with each factor.
Corrosion rate is the key concept in this problem; there are different types of bacteria capable of increasing this rate. Each type of microorganism will use a different mechanism, varying consequently the set of necessary conditions for this phenomenon occurrence.
To assert that MIC process is occurring it is necessary to know type and quantity of bacteria, coating state, complete characterization of soil and corrosion products, cathodic protection history, leaks, defects assessment, etc. Since several factors are necessary to increase corrosion rate, those in which information acquisition will be easier and economic, should be monitored and will be used as indicators of areas with potential MIC problems. Remaining studies would be accomplished to confirm the problem in each location in particular.
All this information will feed a risk model, which will feedback with each new intervention in the pipeline. Finally a risk map will be obtained for each piping in particular, which will permit an adequate risk and resources management in the company.
The Use of Genetic Algorithms in Well Placement Optimization
Authors: Montes Guillermo , Bartolome Pablo , Udias Angel L. 
Published: December 2007

Abstract
This paper is centered in the optimization of well placement using Genetic Algorithms. A Simple Genetic Algorithm program has been developed and it has been used to optimize well placement in two case studies. The effects of different internal parameters on the algorithm performance have been analyzed and a base case configuration suggested. Future modifications are analyzed.
Bimodal Behavior of Mercury-Injection Capillary Pressure Curve and Its Relationship to Pore Geometry, Rock-Quality and Production Performance in a Laminated and Heterogeneous Reservoir
Authors: Leal Libny , Barbato Roberto , Quaglia Alfonso , Porras Juan Carlos , Lazarde Hugo 
Published: December 2007

Abstract
The determination of pore geometry and pore aperture size from mercury injection tests is a very helpful technique. Due to the amount of pressure data points that can be taken, a detailed characterization of the capillarity of the rocks can be accomplished. The size and geometry of the pores are related to variability in grain size, sorting and packing, as well as to factors such as the mineralogy and the diagenetic history of the formation.
This paper presents the results of the integration of capillary pressure curves, conventional core analysis and petrographical Investigation, in a highly heterogeneous pore geometry, where a bimodal behavior of mercury-injection capillary pressure curves was identified, showing two main types of pore throat, one with a larger flow capacity than the other. This analysis was backed up by thin sections made in adjacent samples, where strong changes in sorting, grain size and increment in the percentage of clay matrix can be seen. The changes in pore geometry observed within such small distances, demonstrate the high heterogeneity of the reservoir rock.
An attempt was made to classify the different rock types present in the reservoir, using the Winland (R35) relationship to calculate pore throat radius based on permeability and porosity. Despite the complexity of the pore system, it was found that R35 can appropriately represent the largest portion of the rock volume with the main pore throat radius that contributes to the flow.
The fact that the mercury capillary pressure curves grouped by rock type always show the bimodal shape, was taken into account in order to understand the wells production in the reservoir, because the performance of the wells will depend on the volume of each main pore throat radius in the completed zones.
Operating Benefits Achieved by Use of Advanced Data Communications for Oil and Gas SCADA Systems
Authors: Ehrenreich Dan , May Diana 
Published: December 2007

Abstract
Supervisory Control And Data Acquisition (SCADA) for monitoring of oil and gas systems is now increasingly implemented for pipelines. One of the most important building blocks in such operations is the communications network.1) Widely used communications media in these systems are fiber-optic links, dial-up and leased telephone lines, analog Trunking radio systems2) and digital wireless networks. Modern communication systems allow sending messages from any remote site to any remote site in addition to the control center. Use of advanced communications protocols allows implementation of networking features, remote diagnostics and calibration ("over-the-air"), up- and downloading of programs, parameters, databases, etc.
The Conformity Assessment Program: Accreditation as a Basis for a Modern System of Regulation
Authors: da Silva G. R. , Freire A. F. 
Published: December 2007

Abstract
Firstly, some of the principal challenges for ANP-the Brazilian Regulatory Agency for the petroleum industrial segment - are presented: a) the diversity and the great number of Plants / Facilities and Economical Agents; b) the peculiar context after a monopolistic scenario, in evolution to a liberal one, regulated in a efficient way by the Brazilian Government. Secondly, the bases, the guidelines and the expected results of a Conformity Assessment Program are showed; in a simply overview, the program consider that Authorized Entities by the National Accreditation Organism - INMETRO - would evaluate the expected performance of the petroleum "Players", according to international rules and to specific Regulations. Finally, it is presented a Planning for development and implantation of the Program, including its stages, in an outlined 5W + 2H method (WHAT - WHY - WHO - WHERE - WHEN - HOW and HOW MUCH).
Using Tracers to Characterize Petroleum Reservoirs: Application to Carmopolis Field, Brazil
Authors: Aparecida de Melo Maria , de Holleben Carlos Roberto , Almeida Alcino Resende 
Published: December 2007

Abstract
A specific area under water injection in the Carmópolis field, Brazil, is been considered a candidate area for a polymer pilot project for mobility control. A reservoir characterization and an evaluation of the polymer performance in this high heterogeneous reservoir were required. For this purpose, radioactive, fluorescent and chemical tracers were applied associated with polymer in a reduced area.
The tracer technology has an enormous potential use in Petrobras scenario and this Carmópolis field application was an opportunity to obtain know-how. This paper describes the basic steps from the laboratory tests to the final application including design and programming of field operation. The interpretation of the results using a new approach is also addressed.
Geological Constrained Log Filtering as a Basis for Scale Transference
Authors: da Silva A. , Remacre A. Z. 
Published: December 2007

Abstract
The choice of adequate scaling procedures is a crucial issue to geological reservoir modeling. The integration of fine scale geophysical well logging and petrophysical data with seismic data, and the procedures of transferring information from detailed geological models to large scale, dynamic reservoir models have been theme of intense debate in the literature.
In this work, we propose a new approach that is focused on filtering well logging data in order to control data entry for seismic inversion and subsequent reservoir modeling.
Spectral analysis using Fast Fourier Transform is performed for a set of wells arranged around a single line along the axis of the reservoir. Lithological geophysical logging (GR, sonic, litho-density and neutronporosity log) were fourier-transformed and their power spectra were analyzed. Observed main frequencies were compared to geological derived information in order to retain only significant architectural elements of the reservoir.
Logging data are filtered for these frequencies and the resulting medium scale features are used to model synthetic wells from which the data for seismic inversion were derived. This procedure minimizes higher frequency entries at a level where they can be adequately scrutinized under a very effective geological framework.
The proposed approach effectively handles with the various scale levels of geophysical and geological acquisition by filtering information from detailed logging data, retaining important geologic features characterization, and avoiding the introduction of high frequency noises for seismic inversion algorithms.
Hydrotreatment of Oil Fractions For The Production of Low-Sulfur Diesel
Authors: Albertos Fernando 
Published: December 2007

Abstract
In Europe there is a continuous increase in the demand for diesel fuel. Also, regulations to reduce tail pipe emissions to the atmosphere impose new and more stringent specifications; for diesel transportation fuel, main pressure being on the reduction of sulphur and polyaromatic concentration, reduction of density and decrease of final boiling point. For example, maximum sulphur level allowed now is 350 ppm, with reductions to levels of around 50 ppm foreseen in the short term. Further reductions (even to less than 10 ppm) are also on the horizon.
Hydrotreatment (HDT), as a variety of processes, is the main tool available to the refinery industry to improve diesel quality. This paper deals with the reach of hydrotreatment (HDT) technologies to adapt diesel fuel to the new regulations. The discussion is centred on three aspects: feed processability, process conditions and catalysts employed.
Feed processability is studied in terms of how some feed properties such as sulphur content and specific gravity have an effect on the HDS conversion. Correlations are shown that explain the effect of such variables. Main process conditions such as space velocity and hydrogen partial pressure are studied, and their effect on the product sulphur level is shown. Typical CoMo and NiMo hydrotreatment catalysts are compared upon on the perspective of actual and future specifications. Changes in product properties occurring during hydrotreatment (aromatic content, cetane index and specific gravity) are also shown.
This comprehensive study of the HDT process allows us to estimate hydrotreatment requirements to adapt our refineries to future specifications of the diesel fuel.
Case History: First Coiled-Tubing-Conveyed Live Well Intervention Run From a Semi-Submersible Platform in Brazil to Increase Perforation Length in a Deep Water Horizontal Wellbore
Authors: Rosetto Ilton , Schoener-Scott Martin , Etcheverry Carlos Fulvio , Almeida Jose 
Published: December 2007

Abstract
This paper will describe the first coiled-tubing-conveyed perforating (CTCP) jobs performed offshore in a horizontal well in the Campos Basin, Rio de Janeiro, Brazil.
The operation was needed to obtain the objectives sought after for this well and also to provide a "learning curve" for a major job that was to be run subsequent to this job using the same method. The second job was to be in a water depth of 968 ft., and more than 1,000 ft. of guns would be run. Both jobs will be discussed in this paper along with the advantages gained on the second job from the first experience.
The first procedure required perforating of a 262-ft. interval in a 92-degree horizontal well using 2 in., 6 SPF super deep penetration scalloped guns that would be coiled-tubing deployed through 3-½ in. production tubing. The operation was to be performed from a semi-submersible platform, and the running and retrieving of the perforating guns would have to be accomplished without killing the well so that damaging completion fluids would not come into contact with the reservoir. Requirements for the job were that a safe method be used and that equipment and operational costs be kept at minimum so that a greater return on investment could be realized.
Operational conditions included the following: Perforation was to be conducted with the well in an underbalanced condition so that no formation damage would be sustained.The operation had to be run from a semi-submersible 5that was set in a water depth of 430 ft. (2nd job performed in a water depth of 968 ft.)The gun assembly would have to pass through a 2.81-in. minimum ID.
He two jobs were completed under live well conditions, and both were successful. The estimated cost saving from elimination of 3 days of rig time for the second job was approximately $360,000.
Even more significant for this technology, there are no documented jobs in which this perforation length has been attempted anywhere in the world from a semi-submersible or where the water-depth distance was used as a lubricator for the guns.
Natural Gas Supply/Demand Balance: The Case of Trinidad and Tobago
Authors: Ransome Godfrey , Furlonge Haydn 
Published: December 2007

Abstract
Given the anticipated development of the natural gas industry in Trinidad and Tobago, this paper addresses the supply-demand balance. A mathematical model was developed to determine the optimal reserves addition profile which meets all projected demand scenarios. It was shown that there is a need to boost reserves by up to 39 tscf in a 20-year period to satisfy a high demand scenario and to maintain a minimum reserves to production ratio of 25 years. This substantial volume would undoubtedly pose a significant exploration challenge to the country. However, substantial exploration activity is taking place and the prospects are promising.
Geostatistical Modeling and Simulation of a Compartmentalized Deltaic Sequence, Ceuta Tomoporo Field, Lake Maracaibo, Venezuela
Authors: Smith Richard , Bard Wade , Corredor Jairo , Herweijer Joost , McGuire Simon , Antunez Angel , Block Tatiana , Lazarde Natyuliz 
Published: December 2007

ABSTRACT
The Ceuta Tomoporo Field is a recent development in the Maracaibo Basin ofVenezuela. Recent changes in environmental constraints have allowed PetroleosDe Venezuela S.A. (PDVSA) to begin field development on-shore, adjacent to theexisting development in Lake Maracaibo. A detailed geostatistical model isrequired to make predictions of risk, reserves assessment, and developmentstrategies for potential on-shore development that is now approved. This paperdescribes the geostatistical model and simulation that was performed.
The geological description used to describe the reservoir is based on datafrom 41 wells in the area. The majority of the wells have been drilled in thelast 3 years. Core data is limited, so core data from other wells outside thedevelopment, and vertically similar but different sections, were acquired andevaluated to describe reasonable expectations of porosity and permeability frompotential Eocene reservoir intervals. The geostatistical modeling techniquerequired a unique algorithm performed on normalized well logs to predictdefined rock types associated with expected depositional sand facies.
The geostatistical model was built for a gross interval of approximately 700feet, including the reservoir units commonly referred to in the Maracaibo Basinas units Misoa B3.4 to B6.0. Three environments of delta-marine, distributary-delta, and fluvial-deltaic were identified as a guide to localizeddepositional events. Geostatistical modeling based on 2-foot vertical intervalswere simulated and up-scaled to 73 reservoir simulation layers. Simulationhistory matching of 12 years production data required no adjustments to porevolume but compartmentalization, as evidenced by repeat formation testing (RFT)data, suggests that the structural interpretation can be improved. Waterinjection was simulated to assess reservoir pressure maintenance as a fieldmanagement alternative.
The project identifies the potential to extend present and futuredevelopments in Lake Maracaibo from completely off-shore to include on-shore.The techniques utilized in this work have been successfully demonstrated andare thus transferable to other projects.
Interference Among Acoustic Positioning Systems in Campos Basin, Brazil: A Company's Approach
Authors: Silveira Alexandre C. , Silva do Couto Luiz 
Published: December 2007

Abstract
Exploration and production in deep water has been a challenge to oil industry over the last years. To develop fields in over 1000 meters water depth, Petrobras had contracted most of the total fleet of Dynamic Positioning – (DP) rigs around the world and also anchor handling and special purpose vessels. Work-over operations as well wet Christmas trees installation and the deployment of manifolds and pipelines have been carried out at same time in a small area. The operation scenario can be a target circle of 5 km radio, which can comprise four rigs and others DP vessels operating at the same time. The purpose of this paper is to report how we have managed to control this critical situation and reduce the interference among the acoustic positioning systems of these vessels. For that reason, we have been assuming new technical and administrative procedures. In deep waters the signal to noise ratio at the surface transducer is the critical point. Because of the high nominal ranges required in this application, the acoustic bandwidth is very narrow, less than 30 kHz. The interference problem became more critical during the ionosphere scintillation periods, when the rigs positioning system relied solely on acoustics systems. By controlling the acoustic environment and looking for new technologies, we think we are hoping to reduce this kind of problem. The paper shows how we have controlled the acoustic environment in those areas of interest and how we have plan operations to reduce the possibility of an accident. In addition it also shows graphics and tables that will help the reader to fully understand what we have done.
Opportunities for Redevelopment of Mature Fields by Determinations of Hydraulic Units for Commingled Production
Authors: Villalba Marlene , Mendez Osmary , Marcano Cruz 
Published: December 2007

Abstract
In the Eastern Venezuela, Anaco area, there are about 50 mature fields of condensates and light oil which still have reserves ranging between 50 and 300 million barrels. However, a good portion of the remaining reserves are still trapped due to inefficient drainage and production declination.
This paper presents an analysis method to increase and accelerate production as well as recover additional reserves based on the detection of communication between pay sands. The study have been made in the Santa Rosa Field, which is one of the most important mature volatile oil field in the Eastern Venezuela Basin, with remaining reserves of 321 MMBLS and 4851 BCF. The integration of oil compositional data, gas chromatography and fingerprinting analysis of oils, as well as, pvt data with pressure, well test, production data and geological information have contributed to identify reservoir continuity. The identification of four oil family types into the field was achieved through Geochemistry analysis. Wells correlation reveals significant stratigraphic coalescence, and integration of these results with production and pressure data permitted to identify four hydraulic flow units.
The results of this study helped to understand the vertical and lateral connectivity of the sand bodies and aided in the distinction of areas in the field with the best infill drilling potential, both of which have contributed to optimize well location, recompletion works, and also improved the accuracy of the production performance predicted.
Economic Evaluation of a Multi-Prospect Exploratory Block
Authors: Vukelic M. , Pescara R. , Franco A. 
Published: December 2007

Abstract
This work describes a methodology used to evaluate an exploratory block with 56 prospects and leads. The method is based on Monte Carlo simulations of exploration and development scenarios of the entire block. We obtained probability distributions of production, capital expenditures, cash flow net present values, etc. that allow management to determine the value and understand the risk of the business. The same methodology can be used to evaluate and optimize the exploration portfolio of a company.