bluuebunny/crossref_metadata_2025 huggingface dataset:
Measurement and Modeling of Wax Deposition in Crude Oil Pipelines
Authors: Nazar A. R. Solaimany , Dabir B. , Islam M. R.
Published: December 2007

One of the problems faced by the petroleum industry is the wax deposition in pipelines during transportation of waxy crude oil. Oil companies dealing with waxy crude often spend millions of dollars in remedial procedures. An ideal design should use an accurate mathematical model that would include all salient features of wax deposition and waxy crude transport to predict wax deposition during crude oil transportation. In this paper, a comprehensive mathematical model for quantitative prediction of wax deposition for a multicomponent hydrocarbons mixture (oil) has been developed. The wax deposition is estimated from the diffusion of wax from the bulk towards the wall as a result of temperature gradients. Parametric studies on the variation of the amount of wax deposition were performed for a mixture of toluene and oil wax cut in an experimental setup. Overall predictive ability of the proposed model is excellent for the laminar flow.
Large Amounts of Acid Applied in a Real-Time Flow Mixture for Cleaning a Pipeline while Maintaining Environmental Control
Authors: Suzart J. W. P , Souza D. M. , Conceição A. C. Farias , Santos K. A.
Published: December 2007

This paper presents a method for pipeline cleaning in which large amounts of an acid mixture can be monitored in real-time. The acid concentration can also be modified to prevent environmental damage.

This method was applied to the scale-removal process, but the primary objective was real-time control of acid concentrations for minimizing environmental impact. This treatment completely cleaned the pipe without damaging the surrounding environment.
ARPEL's Approach to the Clean Development Mechanism
Authors: Lee Arthur
Published: December 2007

The Regional Association of Oil and Natural Gas Companies in Latin America and the Caribbean (ARPEL) has a comprehensive membership of state-owned and private oil and gas companies, representing more than 90% of the upstream and downstream operations in the Region. ARPEL is aware of the many concerns and uncertainties of the Kyoto Protocol, which include: Scientific uncertainties about climate change;Costs of emissions reductions;Impact on the demand of fossil fuels; andThe role of carbon sinks.

At the same time, ARPEL considers the Clean Development Mechanism (CDM) to be a key provision of the Kyoto Protocol that needs to be carefully designed to ensure that the common objectives of greenhouse gas emissions reductions, technology development and transfer, and other benefits to numerous partners, stakeholders, and businesses in the Region, are achieved. If developed and implemented properly, the CDM can help build partnerships not only among our own Member Companies but also between the oil and gas industry with other industries, governments, and nongovernment organizations in the Region to reduce greenhouse gas emissions at the lowest cost while promoting new investments, development and transfer of technology, best practices, and sustainable development. This paper outlines ARPEL's interpretation of key provisions of the CDM and makes several recommendations that would strengthen the viability of the CDM in achieving these common objectives.
Design of High Angle Wells in the Santa Barbara Field, Eastern Venezuela
Authors: Flores D. , Gonzalez D. , Rueda M. , Russo A. , Clarembaux J. , Sorrentino Y. , Castillo L. , Villa J.
Published: December 2007

The Santa Barbara Field was discovered in 1988 and is one of the largest hydrocarbon accumulations along the Northern Monagas trend, Eastern Venezuela. The producing formations range from Cretaceous to Miocene age, and the area is structurally complex. For about forty percent of the area, a very abrasive, hard to drill, allochthonous wedge of early to late Cretaceous age, which gradually thickens to the north, has to be penetrated to reach the producing formations, increasing exploitation costs. The field is currently producing light oil and condensates at depths between 13,500 and 18,000 feet. The average temperature of the reservoirs is around 290°F and reservoir pressures range between 8,000 and 11500 psi, depending on relative depletion. Asphaltenes precipitation and sand production are some of the operational problems encountered. Furthermore, parts of the field lays underneath a few towns and villages that constrain a regular drainage with vertical wells. A project to inject 1,200 million cubic feet of gas to maintain reservoir pressure is under way. To minimize production problems, to maximize productivity and injectivity, and to improve profitability of the field, a multidisciplinary task force was formed to plan and design highly deviated wells. In this work, reservoir geology and petrophysics, geomechanical characteristics, reservoir simulation, wellbore stability, construction angle rates, drilling hydraulics and drillstring performance design are discussed. To minimize costs, rig capacity was limited to available equipment. A 75° high-angle well is currently being drilled underneath the El Tejero town to reach previously underdeveloped zones, and the preliminary results of the pilot well will be presented. Total measured depth will be 20,240 feet with a vertical section of 5,500 feet. Simulation results for this design show substantial increase in oil production over a vertical well in the target location using a monobore completion. The designs of a high-angle, gas-injector well and a deep multilateral in the allochthonous region are also discussed. The overall recovery factor of the field may well be increased if oil otherwise left behind in low permeability zones is penetrated by highly deviated wells.
Geological and Geophysical Integrated Methodology for Reservoir Characterization
Authors: dos Anjos C. E. G. , Zucchi H.
Published: December 2007

Well measurements and seismic attributes can be used to derive multi-dimensional calibration functions that are applied to seismic attributes to map reservoir properties. Estimation of various properties is guided by multiple seismic attributes simultaneously. The estimates fit the well measurements and are guided by seismic data away from the wells. Significance estimation and error mapping provide a quantitative measure of confidence.

Specific seismic attributes have been found to correlate well with individual reservoir properties, thus improving the ability to map them. For example, interval velocity and acoustic impedance often correlate well with porosity.

This mapping process was used to define effective porosity and water saturation along the reservoir.
Studies of Sedimentological Heterogeneities and Their Impact in Fluid Flow Simulation
Authors: Carrasco B. N. , Portella R. C. M. , Becker M. R.
Published: December 2007

The fluid flow simulation response obtained using exposures of three depositional systems has important impact on predictive oil recovery as result of simplification processes through faciescaling and upscaling methods.

Based on complex geological models described, successively models have been simplified, so as to create a series of models by showing the ideal level of description of sedimentological aspects for oil reservoir faciescaling.

In the upscaling method, all of three depositional systems have been yielded reservoir attributes that resemble definitely with predictive models.

The difference between them is that in deep-water system, faciescaling method is not applied to transversal shale layers. However, it yielded good results from fluvial and eolian systems, in which most of shale layers are absent or less frequent and rather subparallel to themselves.

Upscaling method in three cases investigated worked well. It does not matter if shaly beds are parallel or transversal to fluid flow, or if shaly beds are hardly dipping or not. In fact, detailed geological descriptions always are needed to support upscaled results.
Uncertainty in Production Profiles on the Basis of Geostatistic Characterization and Flow Simulation
Authors: Salomão M. C. , Grell A. P.
Published: December 2007

The purpose of this work is to proceed uncertainties analysis with respectto the physical properties of a petroleum reservoir, in the process ofgeological characterization and flow simulation model. The approach is appliedin a real case of Campos Basin, in Brazil, and may be helpful to the decisionanalysis concerning the profitability of the exploitation project. The sequenceis performed in four parts: the quantification of the sources of uncertaintiesconcerning the reservoir volume; the quantification of the factors affectingthe oil recovery factor; the quantification of the uncertainty range of therecoverable volume; and the estimation of the production profiles. The firstpart is executed through geostatistic simulation of the net-to-gross variable, associated with variation on the position of the oil-water contact. The secondpart consists on the use of numerical simulation runs to verify the sensibilityof the recovery factor to the variation in the vertical permeability, therelative permeability to water, and the productivity index of the wells, themost important variables in this specific case. The effect of each factor issupposed to be independent of the others, and only two cases, representing thepessimist and the optimist case, are simulated for each variable. As thisindependence is not perfect, two additional simulation runs may be required toadjust the width of the distribution. Having the probability distributions ofthe oil volume and of the recovery factor, Monte Carlo simulations are used toobtain the distribution of the recoverable volume. Each value of reserve isrelated to a production profile, to obtain the cash flow of the project, andevaluate the uncertainty concerning to the economic parameters.
Mathematical Modeling of a VGO Hydrotreating Reactor
Authors: Lopez R. , Dassori C. G.
Published: December 2007

This paper presents a mathematical model developed for the operating simulation of a trickle-bed reactor. Furthermore, the model has been fixed to emulate the operation of the three reactors used at the gas oil hydrotreatment reactors available at Amuay refinery (PDVSA).

The differential mass balances of the chemical species present in the process system are defined based on the mass conservation equation at the gas and the liquid phase. Moreover, mass transfer resistance on the inner catalyst particle is evaluated in terms of the catalyst effectiveness factor. Also, mass transfer coefficients, gas solubilities and transport properties of the chemical species available in the gas and liquid phase are evaluated with the help of mathematical correlations obtained from gas oil desulfurization experiments adjusted at the operating conditions available in the Amuay refinery gas oil hydrotreatment units.

In addition, the model includes mathematical expressions for the rate of reaction (HDS and HDN) described with the help of kinetic equations of the Langmuir-Hinshelwood type. Furthermore, the kinetic parameters involved in the chemical reactions considered in the reactor model were estimated using a multidimensional simplex algorithm under the commercial reactor process conditions.
Optimizing Swabbing of Marginal Wells Through Simulation Studies
Authors: Pérez Anthony Alfaro
Published: December 2007

Oil production through swabbing is an alternative method that becomes attractive when the production from a well is under the economic limit of any conventional system of extraction.

This operation consists of running a plunger with rubber cups into the well, submerge it in the existing liquid and pulling it up, repeating the procedure until drying the well or until it is economically profitable for the service company. After some days to restore the of fluid level the procedure is repeated.

The main objective of this work is to define the optimun frequency of intervention to maximize cumulative production (it is different to the maximum volume), thus resulting in maximize value.

The study allows to obtain sensibility analysis to important parameters as: Optimun extraction of annual cumulative volumeOptimun frequency of interventionMinimum levels of fluid that should be found in the wellsCost of each "swabbing run"Optimun annual expensesMaximum annual income
Santa Ines: Another Stratigraphic Prospect in QLC Block
Authors: Coria C. A , Risi D. H. , Franco A. E.
Published: December 2007

Santa Ines prospect is located 7 Km north of Quiamare field in Quiamare-La Ceiba block (QLC), in Eastern Venezuela basin. This west plunging anticline is directly to the south of the Urica fault and in the front of deformation of the Serrania del Interior.

After the success in prospecting combination traps in Quiamare and Cerro Pelado fields, Santa Ines prospect appears to be an analog of these fields in terms of trap type and reservoir quality.

Parasequence correlations and paleocoastline orientation between QLC fields show a high chance of finding pinchouts in Middle Miocene shoreface reservoirs that could provide an updip stratigraphic closure to the trap. This situation is enhanced by the presence of a maximum flooding surface in the middle part of the target section.

Due to the very scarce seismic coverage, outcrop data and image interpretation were used to better define the structural closure of the narrow anticline nose.

A naturally fractured system is probably the main contributor to the reservoir porosity, as in Quiamare field reservoirs.

Due to the shallow location of the anticline, seal integrity is the key risk for the prospect.
Non Conventional Sucker Rod Pumping for Slim Hole Wells
Authors: Alva Mario , Alfaro Anthony
Published: December 2007

Slim hole wells are usually associated to lifting efficiency problems, specially when completed with very reduced diameter, which is usual in marginal fields to decrease costs and improve profitability.

The objective of this work is to give insight into results obtained using a non-conventional sucker rod pumping in pumping wells of 2.7/8" in diameter. The principal characteristic of the system is the replacement of sucker rods by 1" maccarroni tubing, which reciprocate the pump plunger and direct the flow to the surface. The most important task was to calculate the appropiate pumping action as to have minimal risk to the well.

The same is considered in the modification of the equipment of subsurface (sucker rod pump and maccarroni), polished rod and stuffing box.
Operating Safety on New Maritime Terminal of Crude Oil Shipping
Authors: Marzocca Josè Luis
Published: December 2007

In this document we detail the main technical features and operational safety characteristics of the new offshore facilities belonging to Terminales Marítimas Patagónicas Sociedad Anónima (TERMAP S.A.) which are used for the shipping off all the crude oil produced in the San Jorge Gulf Basin.

The need to adapt business to the growing demands of markets and industries has led the Company to fulfill an ambitious project on the overhaul and revamping of its facilities of Caleta Córdova, Province of Chubut, and Caleta Olivia, Province of Santa Cruz.

Thus, major improvements were performed in order to diminish the shipping time and double the mooring capacity, allowing for the safe and efficient operation of up 160.000 DWT tankers, essential elements to increase the competitiveness of the local crude in the international market.
Utilization of Near Infrared Technologies in Gasoline Blending Systems
Authors: Bloise Guillermo Gerardo , Menez Hector
Published: December 2007

In the present time an important number of spectroscopic methods are becoming available for on line applications, to complement or to substitute traditional laboratory analysis and conventional on line analyser. This methods include ultra - violet (UV), visible (VIS), near infrared absorption (NIR), mediun infrared absorption (MID), nuclear magnetic resonance (NMR), Raman scattering, and mass spectrometry.

Specially the technology of the analysis systems based on the near infrared (NIR) has experienced an important development during the last five years and the application number of this technology in "on line measurements systems" in the petroleum industry has grown notably.

The objective of the present work is to show the characteristics and particularities of this technology and the result of one specific application, the measurement of quality component parameters in a gasoline blending.
The Argentina LPG Law: A Necessity That Cannot Be Postponed
Authors: Pozzo Carlos
Published: December 2007

This document is divided into three parts. The first one reflects the structure of the sector. The second one is devoted to analyze its legal base. Finally the third part deals about the requirements of a new law and the discussion of the most important law projects managed in this moment.

Present situation. Description of the LPG market

The structure by companies of the LPG 2.4 million Tns is shown.

There exist 15 producers in a competitive market. The demand is shared by the domestic market and 900 thousand Tns of exports. The household and industrial consumption grew since 1994, notwithstanding the competition of the natural gas. The petrochemical plants also increased their demand.

Bottling Sector

Although there are 47 companies competing in this market, it is a disloyal competition. It is necessary to eliminate practices like the filling of other brands or outdated bottles and cylinders. The analysis of the rotation index of bottles shows the reality of this market. The bottling sector is suffering many transformations and is the source of many conflicts.

Bulk

This is the new way to sell LPG. Since 1995 it showed explosive growing figures. It is leaded by YPF Gas's aggressive marketing.

LPG Networks

The inactivity of this market and the position of the ENARGAS are analyzed. The obstinacy of setting low prices to protect the consumers affected the development of this interesting service.

Legislation that rules the sector

The role of the different resolutions of the Secretary of Energy and Commerce and also the laws of Trademarks, Consumer Defense and Competition Defense are analyzed.

The Police Power Control issued by the Secretary of Energy by Resolution N 227/98 attempted, with little success, to stop the infractions.

The collection of the VAT in origin by the LPG producers set by the Tax Agency Resolution N°820/00 limited the evasion

The New Law

The law N° 24.076 issued in 1992, that rules the transport and distribution of natural gas, in its 67th article establishes that the regulatory framework of the LPG will be set by a special law. This law has not been issued yet. Our ideas: It is necessary for a law to protect the customers from dangerous practices.More than 6 million bottles have to be refurbished within the next 3 years.Companies’ investments should be respected.This will imply the protection of trademarks and property of the bottles.Free market and efficient control systems are basic requirements.The link between the legal framework and the control agencies is an important issue to solve.

The projects of the Secretary of Energy, CEGLA and others are discussed.
Diesel Oil Market in Argentina: Distortion and Origin
Authors: Barreiro Lic. Eduardo Mario , Rey Ing. Fernando
Published: December 2007

In the Argentina fuel market, Diesel oil amounts more than 60% of the fuels volume. This percentage has been increasing over the years, arriving now to that figure, impossible to be covered by the local refineries, and obliging them to import more and more Diesel.

The required Diesel quality is uncommon in the South American markets. Though not as tough as the European and North American regulations, the norms and specs of our diesel are difficult to find in the region due to its relatively low sulfur content and high cetane number.

So the provision for that increasing market is not regional, and the import prices are getting higher: especially when Europe and United States are searching for the same product.

We present the reasons for which the customer has change its preference to Diesel engines, and the increasing percentage of the Diesel vehicles sold. We analyze the conversion to diesel in the Argentine refineries and it has changed with time.

We study how the refineries total conversion have changed, and how they have reached a physical limit that cannot be surpassed. Besides, they cannot refine more oil because the co produced virgin gasoline must be sold at very low prices.

We study the relative evolution of the taxes, responsible for the problem; we compare with taxes in other countries that have a similar problem and how they are trying to solve this situation.

Finally we present several proposals that might correct, when applied, the Diesel distorted market.
Automotive LPG Development
Authors: Wolff G.
Published: December 2007

Automotive LPG is the most highly developed and widely used alternative fuel in the world. LPG having been included in the European Auto Oil 2 Program as part of the setting out of the fuel market of the future, and the fact that it aids in meeting the European Union air quality-related objectives at the lowest possible cost, means LPG's having clearly been recognized as a clean fuel, signifying a boost to its future development.

This study describes, first of all, the technical aspects of the use of LPG in both light and heavy duty vehicles. Of outstanding importance are the first-generation carburation systems, which were subsequently further improved by means of electronic control systems, in addition to what are known as third-generation gas-injection systems. In following, the advantages entailed in using LPG are discussed, focusing on its storage, the increase of the engine life and the lowering of regulated and non-regulated exhaust emissions. A description is also provided of the LPG's performances, that is, power and fuel consumption. Much of what is said is based on the findings of different in-house tests conducted by Repsol-YPF. Lastly, the main needs are set out as regards of an LPG's future development.
Project Management as an Investment Budget Controller
Authors: Fernández H. , Ardiani G. , Benitez L. , Munizaga F.
Published: December 2007

Project Management (PM) is a tool used in many industries to track large development projects from basic engineering to finalization. The main goals of PM are meeting cost, quality and time objectives. This paper shows basic application characteristics of PM, the tools required in implementation, main problems and results.

Our challenge was to adapt this tool for tracking capital expenditures of projects exceeding their fiscal year budget, at different development stages and classified according to their nature (pipelines, treatment plants, electricity facilities, etc.) or to a common target (a particular field development) and with maintenance programs strongly linked to production.

The PM system was implemented at the Puesto Hernández field, Neuquen Basin, Argentina. Capital expenditures of this field amounted to $100 million. As a result of this implementation and better contract planning, budget deviations were reduced by 90%, and timing, cost and quality objectives were met despite changes to the Investments Plan due to internal and external factors.

In setting up the methodology, it was necessary to adapt Project Management to the accounting management system; develop procedures for programming tasks, tracking project progress and recording changes; coordinate different internal areas; optimize resource allocation; and correct deviations.
Log Normalization, a Very Important Task in the Petrophysical Evaluation for La Peña and Tundy Fields
Authors: Aguirre Omar , Antelo Roberto
Published: December 2007

The well logs available in the La Peña and Tundy fields have been logged for different service companies from the 60's (the oldest wells) up to the present time. The logging tool generations go from the oldest (Neutron in cps, Density gamma gamma, Microlog, Resistivity) to the modern technology (PI, CDL, CN, NMR, ect). This wide variety of logging tools technology made the normalization a critical step before getting into any Petrophysical Evaluation. Some logs corrections such as depth shift, wrong values corrections and eliminations, SP base line and others, were also applied before normalization. The main task of normalization was to obtain an homogeneous log data set because an important number of log traces showed signs of differing calibration and scaling. This became most apparent when the logs were displayed in cross sections and also when cross plots were compared with each other for different wells. This publication shows the importance, benefits and follows the log normalization procedure applied to 79 wells from La Peña field and the 9 wells from Tundy field. Once log normalization was performed, the wireline log data base obtained was consistent and homogeneous which let us count with reliable results in the petrophysical evaluation.
Development and Implementation of an Environmental Management System for an Oil Company in South Trinidad in Accordance with the ISO 14001 Standard
Authors: Ramnath K. , Dyal S. , Seeram B. , Maharaj P.
Published: December 2007

Trinidad and Tobago has the oldest petroleum industry in the world. The activities of this industry have historically impacted the environment and newly drafted environmental rules and regulations of Trinidad and Tobago will require sound environmental management systems by all operating companies in the industry.

In order to meet the challenges of these new regulations, the Petroleum Company of Trinidad and Tobago Limited (Petrotrin) is currently pursuing the development and implementation of an Environmental Management System within its Exploration and Production operations in accordance with the ISO 14001 Standard. This project was initiated in October 1999, and is expected to terminate in December 2001 with international certification.

Petrotrin, realizing the competitive advantages that can result from the integration of an Environmental Management System into its operating systems, has placed the implementation of the EMS as a company strategic goal.

The project was categorized into three main stages: Development, Implementation and Audit/Certification. To date, the Development Stage has been completed and the implementation stage initiated, with the following successes: Allocation of manpower resources in the formation of the Steering and Executive Management Committees, and an EMS Project Team;Training of project personnel in ISO 14001/10/11/12 Standards;Revision of the company Environmental Policy statement;Conducting the Gap Analysis Study;Development of the Implementation Plan based on the results of the Gap Analysis;Initiated the development of the EMS manual and drafted initial procedures as outlined in the Implementation Plan;Collection and analysis of data for identification of Significant Environmental Aspects and impacts for Exploration and Production activities.

The Development and Implementation of an Environmental Management System in accordance with the world renowned ISO 14001 is expected to derive many benefits to Petrotrin such as reduced operating costs, improved financial performance, increased access to markets, improved environmental performance, improved community relations, improved customer relations and employee involvement and education.
Development of Fractured Reservoirs of the Mulichinco Formation Using 3D Structural Modeling: Filo Morado Field, Neuquén Basin, Argentina
Authors: Zapata Tomás , Olivieri Gustavo , Dzelalija Francisco
Published: December 2007

The Filo Morado field produces hydrocarbons from primary porosity and fractured reservoirs such as the Mulichinco Fm., a fine grained calcareous sandstone and sandy limestone with 4 to 6% primary porosity. This unit has been developed as a conventional reservoir; most of the wells resulted dry or with a very low accumulated production. New 3D seismic information is scarce and highly laterally displaced due to the structural and geological complexities. 3D geologic modeling was made from twelve 2D structural sections. The different horizons were connected to generate a 3D solid model, with different velocity layers to perform a depth migration of the seismic data. The corrected seismic data allowed to characterize the 3D geometrical distribution of the faults and geological data. 3D structural analysis, combined with surface and depth data (logs, cores, well cutting, etc.) made possible to propose a kinematic model as a doubling detachment east-directed fold combined with backthrusting that tilted and displaced the flat crest to the west. Fracture geometry was inferred from core analysis, borehole images and outcrops. Fracture genesis may be related to flexural slip and to accommodation zones and to the regional stress field after the folding mechanism was locked. A development well was drilled to structurally evaluate the different segments of the structure. Drilling results as well as production data suggest that the forelimb environment is highly fractured; in accordance with the model predictions.
Maximization of a Field Characterization Using 3D Seismic: Case Study, C-2 Reservoir, Block VIII, Occidental Basin, Lake Maracaibo, Venezuela
Authors: Carrizales R. , Sifonte E. , Aguilar T.
Published: December 2007

In this work a methodology is developed in which is applied the advances of applications of seismic 3D (Variance Cube, Seismic Attributes, Three Dimensional Visualization, incorporating Well/Seismic depth cross sections, and others) in the evaluation of the field, integrating it with the disciplines of the geosciences to obtain a static model of the producing reservoir. This study is of great help in the reevaluation and interpretation of areas currently producing and also gives better definition and characterization of remaining prospective reservoir areas.

The study area is from the middle portion of Lake Maracaibo, Western Basin of Venezuela, more specifically in the Seismic 3D cube of Block VIII. The dataset cube embraces an area of 265 Km2; comprised by approximately 700 Inlines and 1400 Crosslines. Later in the project the study was further detailed in a smaller cube of 112 Km2 in order to study the C-2 reservoir of Block VIII. In total there were 152 wells loaded in the database.

Within the regional stratigraphic column, there were interpreted four (04) Seismic reflectors range from the Cretaceous period into the Miocene, and these reflectors show strong acoustic impedance and are of great areal extension, which are: Socuy member of the Creatceous Colon Formation, Guasare Formation(Paleocene), Top of Eocene Uncomformity and the Rosa Formation (Miocene). Subsequently the C-2 and C-3 Sands of the Eocene Misoa formation were interpreted in VIII Block.

The objective is to study the C-2 Sand of Block VIII which contains 190.7 MMBLs POES (original oil in place), remaining oil in place of 11.7 MMBLs, and accumulated production of 33.4 MMBLs with an oil retrieval factor of 23.65 % and oil of gravity of 27.5° API. This sand is segregated into six (6) separate reservoirs in this block.

The application of this methodology helped in finding new develoment prospects and increased the net recoverable barrells in the area of study.
Evaluation of the Dispersion Model in a Refinery, Lujan De Cuyo
Authors: Correa G. , Fernandez L. , Vera F.
Published: December 2007

Environmental Management System faced by Repsol YPF has implicating the installation of dispersion models of pollutants in the industrial pole of Mendoza. For this utilization with more complex objectives (for example: environmental impact studies, comparison with procedures of quality of the air, etc.) is necessary to confirm the predictive capacity of the model. The used method was to compare the results of model with monitoring data during the same period. It must be emphasized that the credibility of the confirmation requires a top quality in all the data used in the comparison, that is to say in monitoring data, emission and meteorology. The duration of the evaluation of the model was for a year.
Waterflooding Optimization Using Biotechnology: 2-Year Field Test, La Ventana Field, Argentina
Authors: Maure Alejandro , Dietrich Forrest , Gomez Ulises , Vallesi Javier , Irusta Marcelo
Published: December 2007

Biotechnology improved water flood performance during a two-year test in Victor Claro reservoir layers C2-D2, La Ventana field, northern Cuyo Basin, Mendoza Province, Argentina (Figure 1, 2 and 3). Paraffinic oil has been produced by water flooding since 1989. The objective of this project was to determine the technical and economical feasibility of Microbial Enhanced Oil Recovery (MEOR) methods for field-wide application in mature water floods. This paper explains the continuation of a pilot study of controlled microbial colonization in producer wells begun in La Ventana field in 1995.

Fluid property alterations were evaluated using a complete set of rheology parameters, specific geochemical fingerprints and bioassays on more than 82 samples from La Ventana and neighboring fields. The oil proved to be highly bio-treatable and formation water to be compatible with MEOR requirements. Reservoir conditions, including rock properties, pressure and temperature were also favorable.

Microbial Inoculation Program started December 1998 and was implemented by systematic treatment of injected water using hydrocarbon degrading anaerobic-facultative microorganisms on a non-regular injection pattern having direct influence on four neighboring producers (Figure 4). A complementary tracer field test using Tritium permitted validation of inter-well connectivity and allocation factors initially inferred by the use of streamline simulation. Pre-MEOR and Post-MEOR fractional flow field performance in producers was also correlated with theoretical predictions using a proprietary 2D, vertically integrated streamline simulator. The tracer and simulations contributed to better understanding MEOR mechanisms and to better designs for bio-treatments.

Original oil production decline rates improved. Increments in oil cut were measured using conventional methods for 24 months after MEOR program started (Figure 19). Two combined mechanisms help explain the change: Further depletion of residual oil saturation by in-situ production of metabolites with low interfacial tension andImproved oil mobility from short-chain solvents originated by microbial alteration of heavy paraffinic ends.

Further evaluations will cover extension of pilot period and economic feasibility analysis for large-scale MEOR implementation in other zones under conventional flooding.
SAGD Performance Optimization Through Numerical Simulations: Methodology and Field Case Example
Authors: Egermann P. , Renard G. , Delamaide E.
Published: December 2007

SAGD is a very promising recovery process to produce heavy oils and bitumen resources. The method ensures both a stable displacement of steam and economical rates by using gravity as the driving force and a pair of horizontal wells for injection/production. After several years of small scale field tests (pilots), the method is now considered as mature and large scale projects are scheduled in a near future (in Canada for instance). Nevertheless, both technical and economical success of the process require a satisfactory development of the steam chamber, which can be achieved by well monitoring (i.e. steam trap control).

This paper presents a general methodology based on numerical investigations to obtain and maintain an optimized development of the chamber throughout the production life of the wellpair. First, the methodology is explained on a synthetic case and applied to a real field case example. Field data are first history matched with the model and then the proposed approach is used to evaluate how the oil production could have been enhanced and optimized further.

It is shown that an optimized steam chamber development is obtained by adjusting the steam injection rate to the potential of the reservoir (fluids and geology) and by monitoring the production rate during the process/operations to keep the steam chamber as large as possible but away enough from the production well to prevent any steam breakthrough. The results are in good agreement compared with Butler's analytical model (oil rate and steam chamber shape). A very good history match is obtained in the field case example. The proposed methodology shows that oil production rate can be doubled when injection/production rates are adapted to the SAGD reservoir potential.
Reservoir Characterization of the Orinoco Heavy Oil Belt: Miocene Oficina Formation, Zuata Field, Eastern Venezuela Basin
Authors: Kopper Robert , Kupecz Julie , Curtis Carl , Cole Tony , Dorn-López Donald , Copley Jeffrey , Muñoz Alberto , Caicedo Vladimir
Published: December 2007

The Zuata Field, located on the southern flank of the Eastern Venezuela Basin, produces heavy oil from porous unconsolidated sandstones of the Lower Miocene Oficina Formation. The Oficina Formation is composed of multiple depositional sequences which display complex erosional geometries. This creates an intricate reservoir architecture as younger fluvial systems down-cut, erode and re-distribute the sediments of earlier-deposited systems within each depositional sequence. Superimposed on this intra-sequence complexity is the downcutting and interconnection of sands of different depositional sequences.

The Oficina Formation within the study area can be subdivided into eleven depositional sequences. Each depositional sequence has been characterized in terms of environments of deposition and mapped, which has allowed visualization through time of the facies and reservoir geometries. Within sequences, environments of deposition include a mix of fluvial, distributary channel, estuarine, tidal channel, delta plain and coastal plain, resulting in variable net to gross ratios and variable kv/kh. Productive sands are located within incised valleys, usually within the basal part of each depositional sequence, while sediments in the inter-valley areas comprise a combination of older (pre-incision) deposits and thin delta plain / coastal plain deposits. These are variously intercalated siltstones, fine-grained sandstones and coals, and are generally non-productive.
Enhancing Steamflood Effectiveness by Horizontal Producers
Authors: Leonhardt Bernd
Published: December 2007

The Emlichheim oilfield is located in North-West-Germany on the Dutch-German border being the Southern downdip part of the Schoonebeek anticline. The field was discovered in 1943 and came on production in 1944. Since production startup, Wintershall operates the field as owner of the concession (90 % share of interest) in a joint venture with Mobil Erdgas-Erdoel GmbH (10 %).

For more than 50 years an average crude oil production of 150,000 tons/yr (1.05 MMstb/yr) has been maintained. Starting with huff ‘n’ puff and hot water flooding in the late 60's, the first steam flood project was implemented in 1981. Further steamflood projects started in 1989, 1992, 1993, 1994 and 1998 in different areas of the field. Until 1997, only vertical production wells were drilled in the field. Wellbore stability seemed to be a major problem for drilling horizontal wells in the unconsolidated sandstone reservoir at that time.

In 1999 an innovative steamflood project was started with three newly drilled horizontal producers surrounding a vertical steam injector. First results are showing a significant improvement in the performance as compared to the earlier projects and offer new chances for further development of the field. Today, the field could no longer be operated without the steam projects as roughly 95 % of the field production is coming from thermal EOR.

This paper gives a brief overview of the field and its production history, the planning and realization of a current steamflood project using horizontal well technology as well as its performance compared to the earlier projects. It also describes the experience of drilling horizontal wells in the unconsolidated sandstone. A brief outlook to the future field development is given.
Experiences Using an ESP Application on Heavy-Oil Cold-Production Automation in Eastern Venezuela Fields
Authors: Aponte H. , Toussaint L. , Ramos M.
Published: December 2007

PDVSA Automation Strategy for Electro-Submersible Pump artificial lifting of heavy and extra-heavy crude is inspired on the reality of subsurface conditions and successful experiences from applying ESP methods. The usage of pure thermal and heating methods to manage crude viscosity is constrained due to the risks it represents in damaging the pump-motor arrangement. On the other hand, the advantages of using the heating effects of the motor, combined with the injection of light crude as a dilute fluid, both subsurface and surface to decrease crude viscosity, have given great results when incorporating subsurface and surface automation strategies.

The benefits resulting from the use of an integrated strategy, is a consequence of maintaining production rates constant, regardless of day and night viscosity variations and other changing conditions from changes in the process behavior. Additionally, a less hostile operating environment results in a longer lifetime of the motor-pump arrangement. A case study considering the controllability of the ESP system running in a heavy and extra-heavy cold production environment is presented.
Promising Progress in Field Application of Reservoir Electrical Heating Methods
Authors: Sierra R. , Tripathy B. , Bridges J. E. , Ali S. M. Farouq
Published: December 2007

Electrical Heating of heavy oil reservoirs has been successfully applied in near wellbore regions. Well stimulations through downhole resistive, dielectric, or induction electric heating systems when applied in suitable reservoirs can triple flow rates for a small additional operating cost. In such cases high-energy conversion ratios such as 10-15 bbls. Of oil for every bbl of oil consumed at the power plant can be achieved. Applications of electric heating can particularly be beneficial in situations where steam cannot be used due to either depth, formation incompatibility, low incipient injectivity, excessive heat losses or existence of thief zones. Additionally, for reservoirs already having a high temperature in the 60-80 degree C and higher range, only a small amount of electric heating-stimulation is enough to increase oil production by an order of magnitude. Some Orinoco reservoirs of Venezuela fall into this category. Heavy oil reservoirs, overlain by heat sensitive permafrost, may also find electrical heating a viable thermal stimulation technique. Electrical heating process has also been adapted to apply in preheat phase of other complimentary processes like VAPEX. The process also has been investigated for hot water flood in deep reservoirs. This paper proposes to use downhole electric systems for stimulating for both vertical and horizontal wells in such reservoirs. Using CMG's thermal simulator-STARS (ref. 7), results of several worldwide investigations are included. A summary of field applications is also presented. In addition, incremental oil recovery vs. energy consumption is tabulated.
Helitherm-Solar Power Throughput Enhancement and Heat Tracing for Heavy Oil Pipelines
Authors: Lasich John , Kaila Neelabh
Published: December 2007

Helitherm is a passive and stand-alone solar thermal powered heating system for pipelines and vessels and is applicable for crude oil/product flow enhancement and heat tracing in above-ground installations.

Helitherm's operating principle relies upon an integrated thermal diode, which traps sunlight and retains heat. The pipeline is fully insulated and therefore heat loss is minimized and the elevated temperature maintained.

This paper specifically addresses the throughput enhancement of heavy crude oils using Helitherm technology. In order to quantify the throughput enhancement, Solar Systems has developed a computer model called Helitherm Dynamic Simulator to evaluate the pressure drop and temperature profile of a Helitherm pipeline and compare it with a bare pipeline under average sunshine conditions. This program can also be used for nighttime analysis of pressure drop and temperature profile in Helitherm and bare pipelines. This program evaluates the pressure drop at crude oil viscosity corresponding to an integrated average pipeline temperature. FEA techniques are also being developed to obtain a more accurate pressure and temperature profile.

Based on this computer model, Solar Systems has conducted several feasibility studies for oil companies around the world. Two studies, one for Petroleos de Venezuela SA and the other for Pertamina (Indonesian National Oil Company) have been discussed in detail.

For PDVSA, the existing throughput of 231BOPD will increase to 306 BOPD, resulting in a percentage increase of 32.4%.

Similarly for Pertamina the increase in throughput is from 386.4 BOPD to 452.4 BOPD, resulting in a percentage increase of 16.8%. The payback period for both projects is less than one year.

In addition to the increase in throughput under no flow (stagnation) conditions, the pipelines are maintained at a temperature higher than the pour point at all times. This eliminates the pipeline start-up problems.

Another version of the computer program (called Helitherm Static Simulator), which predicts the temperature profile of a solar heated pipeline during no flow (stagnation) conditions has been developed and validated for a range of climatic conditions.

Solar Systems Pty Ltd has analyzed the Thayfut pipeline for Petroleum Development of Oman to demonstrate the capability of Helitherm as a stand-alone heat tracing system.

Both these programs would assist a pipeline designer in evaluating the pressure drop, pipe sizing, selection of pumps, investigating pipeline start-up problems and computation of thermal expansion in pipelines.

Helitherm technology is an innovative and economically attractive alternative to the conventional electric or steam heat tracing of pipelines or utilization of drag reducing agents (DRA's) or pour point depressants.

Depending upon process requirements, this technology is specifically suited for tropical and mid latitudes. This technology is also suitable for vessels.
Application of Advanced Heavy-Oil-Production Technologies in the Orinoco Heavy-Oil-Belt, Venezuela
Authors: Robles Jorge
Published: December 2007

The successful application of state of the art drilling technologies such as horizontal and multilateral wells for the development of Zuata field in the Orinoco Belt demands improvements in the areas of artificial lift, fluid gathering and fluid treatment. The economic production of wells with initial potentials beyond 3,000 nbpd challenges both equipment and process.

This paper summarizes the latest experiences of Petrozuata C.A. in the Zuata field in the use of electric submersible pumps, and progressive cavity pumps, as well as the application of state of the art instrumentation for monitoring of production parameters.