bluuebunny/crossref_metadata_2025_split huggingface dataset:
A Unique Experimental Study Reveals How to Prevent Gas Migration in a Cemented Annulus
Authors: Talabani Soran , Chukwu G. A. , Hatzignatiou D. G. 
Published: December 2007

ABSTRACT
An experimental study was carried out to investigate the performance of new cement additives in controlling or eliminating gas migration through cemented wellbore annulus. The shrinkage behavior of the proposed cement slurries was obtained as a function of time and applied pressure at constant bottom hole temperature. Ultra-sonic measurements were correlated with the strength and bulk density of the cement. These measurements were used to screen out cement slurries for further testing in a cement simulation unit This unit consists of a 7″ casing pipe placed inside a 10″ controlled temperature water bath. The experimental unit was 6 ft long and was used to simulate borehole pressure and temperature conditions. The borehole was modeled by drilling a 2″ diameter hole through 2.5 ft long cylindrical core samples.
A large number of additives was tested to evaluate their effects on the cement volume fluctuations which are the primary causes of gas migration. A thorough procedure was followed to evaluate the effectiveness of all tested additives in controlling or eliminating the creation of micro-fractures during cement setting under borehole pressure and temperature conditions. The results obtained from this extensive experimental study show that the use of the proposed additives decrease significantly the cement volume fluctuations during cement setting.
The new cement additives proposed in this study reduce the contraction-expansion mechanism effects during cement slurry setting, thus minimizing and controlling the creation of micro-fracture.
Development of Asphaltene Phase Equilibria Predictive Model
Authors: Nor-Azlan N. , Adewumi M. A. 
Published: December 2007

ABSTRACT
Asphaltene deposition is a very serious and complex problem. The damaging effects of this problem are common in all facets of petroleum production, processing and transportation. The mechanisms of asphaltene precipitation are still not fully understood due to the lack of understanding of the physicochemical behavior of asphaltene as it exists in the crude oil system. In this paper, a model based on the statistical thermodynamics of polymer solution is described for the phase behavior of asphaltenes. A Vapor-Liquid-Liquid Equilibria (VLLE) model is employed, using separate VLE and LLE calculations to predict the phase splits (vapor, asphaltene and crude oil fractions). The model uses the concept of material balance by coupling with the Flory-Huggin theory of polymer solution. Various theoretical equations of state are employed as options for the estimation of the component properties for the lighter fraction. The properties of the heavy fractions in the crude oil system are determined using empirical correlations. The resulting model allows us to predict the onset of asphaltene flocculation as a function of temperature, pressure and compositional changes in the crude oil system. This model can be used as a basis for designing petroleum production systems, including separator design, production well performance analysis, pipelines and EOR projects.
A Comparative Analysis of the Performance of Two-Phase Relative Permeability Models in Reservoir Engineering Calculations
Authors: Siddiqui Shameem , Ertekin Turgay , Hicks P. J. 
Published: December 2007

Abstract
A comparison of ten two-phase relative permeability models is conducted using experimental, semi-analytical and numerical approaches. Relative permeabilities from the models are compared with data obtained from 12 steady-state experimental runs on Berea and Brown sandstones using different combinations of three white mineral oils and 2% CaCl2 brine. Relative permeability data from four of the experimental runs are used to predict the displacement performance under Buckley-Leverett conditions and the results are compared against those predicted by the models. Finally, waterflooding performances predicted by the models are analyzed at three different viscosity ratios using a twodimensional, two-phase numerical reservoir simulator. The model results are compared against the experimental data using three different criteria. The models predict relative permeability to oil, relative permeability to water and relative permeability ratio values with varying degrees of success. The Wyllie-Gardner, Honarpour and Fatt-Dykstra models predict the best values for the relative permeability ratios. The Wyllie-Gardner, Honarpour and Burdine models give better results than the other models under Buckley-Leverett type displacement conditions. The simulator runs show that all models are able to run without problems (for the given conditions) although the Naar-Henderson model yields significantly different results than the other models. The simulator data show that as the oil-water viscosity ratio increases, the difference of performance predicted by different models diminishes. Overall, the Wyllie-Gardner and Honarpour models are found to yield consistently better results than the other models at the experimental conditions.
Drag - Bit Model Including Wear
Authors: Hareland G. , Rampersad P. R. 
Published: December 2007

Abstract
The model presented in this paper is a new approach to predicting the performance of full-hole and core drag bits. The model is based on theoretical considerations of single-cutter rock interaction, lithology coefficients and bit wear. Several new modeling features are introduced, these include "equivalent bit radius", "dynamic cutter action", "lithology coefficients" and "cutter wear". The model is applicable to all types of drag bits (Natural Diamond Bits (NDB), Polycrystalline Diamond Compact Bits (PDC) and any Geoset Bits) with correct cutter geometrical description. The model is useful for pre-planning, day to day and post drilling analysis, as well as drilling optimization.
Application of the model to evaluate drag-bit performance has shown good results in several lab and field cases. The advantages of this model include, optimization of operating parameters, optimization of bit parameters and support of a total drilling system for penetration rate, solids control and hydraulics optimization. In addition, use of the model is simple and straight forward, data requirements are standard and readily available. Lithology coefficients can be obtained from lab data or one set of drill-off and/or bit performance test in the field. Penetration rates can be predicted by the model for different lithologiεs using rock strengths obtained from offset drilling or log data. In other words, the model will predict penetration rate for any set of operating conditions, formation description and bit parameters.
Experience in Drilling Deep Wells through Two Trouble Zones with Different Characteristics
Authors: Pereira C. R. , Perez J. R. 
Published: December 2007

Abstract
The purpose of this paper is to describe the experience obtained by Lagoven, S.A. Petróleos de Venezuela, during the drilling operations in Block "B", southern Lake Maracaibo. A 5 7/8" directional hole was drilled through two trouble zones with different characteristics. The zones are the Upper Cretaceous, Colón formation, and the Lower Cretaceous, Cogollo group. The Colón is composed of a highly hydratable, pressurized shale which requieres high drilling fluid densities for control. The Cogollo group is composed of fractured limestones with normal pore pressure. Lost circulation and differential sticking are the problems associated with these formations. In addition, the Cogollo group contains the productive zones in this area.
This study highlights the techniques, equipment, and materials which allowed the successful completion of the well, offering new drilling alternatives for future wells in this area.
Application of Genetic Algorithm on the Distribution of Gas-Lift Injection
Authors: Martinez E. R. , Moreno W. J. , Moreno J. A. , Maggiolo Ricardo 
Published: December 2007

ABSTRACT
In this paper is described the application of a genetic algorithm (GA) to the problem of optimizing production in oil fields operating under the gas lift method. The chosen computational methodology proves to be very effective and efficient in the execution of the task. The method provides assistance to the production engineer en the problem of assigning optimum gas-injection rates to each individual well given an available total gas supply for the field. This development is incorporated as an important utility in a system for computer aided analysis and optimization of gas lift wells developed in Corpoven S.A. (CORPOLAG).
The gas-lift optimization system is implemented by means of a genetic algorithm that executes an "intelligent search" in a "gas-injection rate" space. It obtains automatically and with a reasonable small computational effort a distribution of gas-injection rates for the wells in the field. This gas-injection rate is compatible with the restriction of the available gas supply for the field, and maximizes the total quantity of produced liquid.
Horizontal Drilling in a Reservoir under Secondary Recovery
Authors: Cicchitti A. O. , Martinez R. A. 
Published: December 2007

ABSTRACT
Puesto Hernández Field is located in the north of Neuquén province, and it extends as far as the south of the Mendoza province in Argentina. In 1969 the field began to be developed, producing at present (September 1993) 47,175.0 stbd (7500.0 m3/d) of oil with 387 producing wells. The cumulative oil production is 194.63 MMstbo (30.90 MMm3).
In 1976 waterflooding was started in the Avilé sand reservoir, responsible for the 83% of the cumulative production. The present recovery is 30% of the OOIP and 41 % final recovery is expected to be reached.
A considerable reserve volume from the Avilé reservoir is still undeveloped because it lays underneath the Colorado River, which goes from north to south through the oilfield. Horizontal drilling has been chosen as a suitable technique to produce such reserve.
In this report the estimation of the geometric characteristics of the well and its location, the productivity index (through a probabilistic calculation) and the selection of the lift system are considered. Also, aspects related to well drilling and completion are mentioned.
Through data obtained from the open hole logging, pressure measurements and production records, the estimates considered are finally compared. The succesful result of this well will allow the development of the reserves with the drilling of producing and injector horizontal wells.
Horizontal Well Transient Pressure Testing in Coalbed Reservoirs
Authors: Sarkar P. , Rajtar J. 
Published: December 2007

ABSTRACT
The dual porosity, anisotropic properties of coal beds make them good candidates for horizontal well completions. This paper presents an analysis of transient pressure response of a horizontal well in a coalbed reservoir. In general, the early time pressure response is distorted by the effect of wellbore storage. The general practice in such cases is to evaluate the time to the end of wellbore storage in a horizontal well using infinite conductivity fracture solutions. In this paper, a new, semi-analytical solution is developed to account for wellbore storage and skin effects on the pressure response of a horizontal well. This solution is developed for semi-infinite, anisotropic coalseam reservoir with single phase gas flow. With this solution, type curves can be generated for particular applications, allowing for calculation and verification of reservoir parameters including sorption properties of coals. Examples of the type curves are presented. An example of the analysis is given.
Methanol as Fracture Fluid in Gas Wells
Authors: Hernández J. M. , Fernández C. T. , Scianca N. M. 
Published: December 2007

Abstract
This paper describes the experience obtained by Pluspetrol in the use of Methanol as fracture fluid in gas wells. It analyzes the physio-chemical properties, enumerating their advantages and disadvantages. It describes the fracture procedure, the precautions and security measures taken and finally compares the results obtained with other fluids.
The use of Methanol as fracture fuid requires a complete knowledge of its properties and compliance with all precautions and security measures necessary. If all the proper information is taken into consideration, the use of Methanol is more adventagerous when compared to other fluid
A Mobility Driven Fingering Approach to the Field-Scale Simulation of Oil Recovery
Authors: Zolotukhin A. B. , Frick T. P. 
Published: December 2007

AbstractA stochastic simulation technique introduced recently has been successfully employed for the study of various unstable growth processes (polymerization, electrochemical deposition, dielectric breakdown of insulators, etc.) of different physical nature. Uncertainties in reservoir characterization and instable displacement processes necessitate the application of models based on stochastic and fuzzy rather than deterministic approaches.For a field-scale simulation of oil recovery a Mobility Driven Fingering (MDF) model has been developed. This approach is a further generalization of the Permeability Driven Fingering (PDF) model for multiphase flow. The main new feature of the MDF compared to the PDF model is that the growth of the displacing fluid cluster is governed by the actual mobilities of phases at the displacing front. Results of a field-scale stochastic simulation based on the MDF model with biased randomness are quite different from those obtained by conventional deterministic modeling techniques.The application of the MDF model to the field-scale simulation of oil displacement can reveal different instability phenomena such as viscous fingering and oil trapping, and how they affect the overall field performance. The model has been proved to be a useful tool for screening different instability phenomena caused by reservoir heterogeneity as well as differences in fluid mobilities.
Horizontal Re-entry Drilling Experiences in Non Consolidated Sands in Eastern of Venezuela Existant Vertical Wells
Authors: Sandoval D. A. , Garcia A. A. , Herrera C. J. 
Published: December 2007

ABSTRACT
This paper describes the horizontal reentry drilling experiences in non consolidated sands achieved by Lagoven, S.A., a subsidiary of PDVSA, in some existing wells at Eastern of Venezuela. Re-entry well planning, mud type, operational problems observed, are developed in this paper. Also, previous horizontal drilling experiences in the area are referred here. A total of 11 existing vertical wells have already been drilled, reaching horizontal drainage sections between 800 to 1600 ft. An excelent response of the sands for the medium radius application was observed.
A Thermodynamic Approach to Determine Convergence Pressure in Multicomponent Systems
Authors: Rivas O. R. 
Published: December 2007

ABSTRACT
A new thermodynamically sound procedure is developed in this work to unequivocally determine the convergence pressure for multi-component hydrocarbon mixtures by a two cell model. Convergence pressure is an important parameter used to determine liquid vapor equilibrium constants by means of Equilibrium Ratio Charts extensively published by the Natural Gas Processors Association (NGPA).
The method is based on assuming that multicomponent mixtures, in both the gas and liquid phases, can be represented thermodynamically by two kinds of cells or pseudo-components which are forced to have identical properties in both phases. The difference in the actual compositions of the phases in equilibrium are taken into account by having a different cell ratio in the liquid cell from that in the gas phase. The properties or characteristics of the pseudo-components are determined based in the distribution of the real components in the cells. These distributions are given in terms of the Boltzman factors of the individual chemical species, based on the concepts of the local composition theory, widely used in the thermodynamic of solutions.
Once the two cells are defined, we have an equivalent binary system whose convergence pressure is the critical pressure of a mixture of the two cells, whose critical temperature is the temperature of the system.
Simulation of Naturally Fractured Reservoirs Using the Hybrid Finite Differences/Boundary Element Technique
Authors: Vieira M. A. , Maraven S. A. , Roegiers J. C. 
Published: December 2007

Abstract
Rock deformability can greatly affect the response of naturally fractured reservoirs when subjected to changes in fluid pressure. This paper describes two numerical models that were developed to understand some of the fluid-rock interactions that can take place in this type of reservoir. Both models were used to study the response of a small ‘sugar block’ reservoir dissected by a large number of fractures and subjected to a number of field conditions and production rates. Results obtained during this preliminary phase indicate that fracture deformability plays a fundamental role in reservoir performance, and the associated compaction can represent an additional drive mechanism, even if significant reductions in fracture permeability are expected.
The newly developed models are useful reservoir management tools which allow to investigate the effect of matrix porosity and permeability, fracture aperture, mechanical properties, anisotropy and production rates on reservoir performance.
Jet Frac Porta-Skid - A New Concept in Oil Field Service Pump Equipment
Authors: Cooper Bob , Lewis Bill 
Published: December 2007

This paper was prepared for the 44th Annual Fall Meeting of the of the Society of Petroleum Engineers of AIME, to be held in Denver, Colo., Sept. 28-Oct. 1, 1969. Permission to copy is restricted to an abstract of not more than 300 words. Illustrations may not be copied. The abstract should contain conspicuous acknowledgment of where and by whom the paper is presented. Publication elsewhere after publication in the JOURNAL OF PETROLEUM TECHNOLOGY or the SOCIETY OF PETROLEUM ENGINEERS JOURNAL is usually granted upon request to the Editor of the appropriate journal, provided agreement to give proper credit is made.
Discussion of this paper is invited. Three copies of any discussion should be sent to the Society of Petroleum Engineers office. Such discussion may be presented at the above meeting and, with the paper, may be considered for publication in one of the two SPE magazines.

Abstract
Increasing demands of the free world oil industry call for pumping equipment that can be moved to any location in the world within a matter of hours. Many times these locations are remote and inaccessible to conventional equipment. Offshore drilling and production requires equipment capable of a production requires equipment capable of a high degree of portability and operation in a minimum of floor space. High performance pumping equipment is an performance pumping equipment is an example of this type service. To meet these demands containerized turbine-powered fracturing pumping units have been developed suitable for movement by air cargo plane, helicopters, boat and land vehicles. Basic features include small size, containerization, high horsepower, and high mobility. Each unit consists of three sections: A standard Halliburton HT-400 pump, a transmission and accessories section, and a gas turbine power section. Each section is interchangeable with the same section in all other units. This equipment is now available to the oil industry and is scheduled for operation in the Eastern Hemisphere after blowout pumping jobs are completed in South Louisiana.

Introduction
The petroleum industry is supported by numerous, highly-specialized, service companies. Creating, providing, and operating equipment capable of pumping fluids beyond the capacities of pumping fluids beyond the capacities of normal drilling rig components is one such service. Generally, operating time at the well site for this service is brief and long periods may elapse before service is again necessary on any given location Normally, this pumping equipment is made available where ground transportation is feasible with equipment mounted on trucks or trailers. (A truck-mounted unit may be viewed in Fig. 1). Marine installations commonly are equipped with service company skid units permanently installed on the rig. (A permanently installed on the rig. (A typical offshore skid is shown in Fig. 2).
Simulation of the Santa Barbara Field, El Tejero - Bosque Area
Authors: Todd M. , Cabrera J. , Achong C. H. 
Published: December 2007

ABSTRACT
A numerical compositional simulation based reservoir engineering study has been made of alternative recovery processes for the Santa Barbara field, El Tejero-Bosque area.
The Santa Barbara field reservoir is comprised of two productive zones, the Naricual and the Cretaceous, totaling about 2,500 feet of thickness. The reservoir is estimated to have originally contained 4.6 billion barrels of stock-tank liquids in the form of condensate in the gas zone and black oil in the oil zone, and 20.5 trillion scf of gas.
This paper describes the results of a mechanistic study, designed, to examine the physical mechanisms that govern fluid hehavior, transport and production in the reservoir. The study utilized numerical models of two prototype regions, of the reservoir, representing different reservoir characteristics. The process investigated include straight depletion, pressure maintenance at 8000 psi and 6000 psi by injection of either inlet (separator) or outlet (dry) gas from the local cryogenic gas plant, re-injection of separator gas produced, and water injection into the oil column.
Also were investigated the effects of completing the wells, above or below the gas oil transition zone. The hydrocarbon fluid column at Santa Barbara is highly unusual, characterized by a variation in com position with depth, being an undersaturated rich gas at the top and an undersaturated oil at the botton, both separated by a transition zone. It was determined that condensate recovery is highly sensitive to reservoir pressure performance, and independent of the composition of the gas injected Best recoveries were obtained with injection of dry gas high pressure.
Audits Emphasize Need for Long-Term Relationship to Improve Prevention
Authors: Bobillier A. A. Y. , Keary Tim 
Published: December 2007

Abstract
Sedco Forex is a drilling contractor that operates approximately 90 rigs on land and offshore, worldwide. Similarly to clients and regulatory bodies, Sedco Forex has developed safety drilling policies, standards and regulations to minimize hazards at the drilling site. The effort imposed on field supervisors to follow these internal and external requirements has increased, a trend that shows little sign of abatement.
It has been found that field training and regular inspections by Line Management are a key ingredient in reducing injuries. Methods of promoting education, measuring compliance with standards and evaluating progress are used by field supervisors with encouraging results.
Join audits are still identifying many inconsistencies in the overall approach to HSE management at the rig site. The Oil Companies main operating risks differ from the Contractors. Training needs vary, emergency response procedures may be conflicting, and even HSE statistics are not always comparable.
This paper proposes solutions to improve this situation and help the key players who must make it happen i.e. the line management.