bluuebunny/crossref_metadata_2025_split huggingface dataset:
Pressure Transient Data Acquisition and Analysis of Pumping Wells State of the Art
Authors: Da Prat G. , Pacheco E. , Sierra L. 
Published: December 2007

AbstractIn this work the advances in pressure transient data acquisition and analysis of pumping wells are presented. A brief summary is presented on methods used in the past 20 years for testing pumping wells. A comparison is made between pressure data acquired using bottom hole gauges and that based on indirect calculation of the bottom hole pressure by determining the liquid level in the annulus acoustically measuring the surface annulus pressure, and calculating the bottomhole transient pressure. The quality of the acquired data using the previously mentioned method is the main topic of discussion and its use and/or limitations for resevoir and well evaluation. Several field examples are used to ilustrate the presentedmethods. As a main result it is concluded that pressure data acquisition using acoustic methods is the best alternative for pumping wells. The pressure data resolution and accuracy is similar to a conventional amerada type of gauge. However the main advantage is that we can get the whole pressure transient profile (flowing/buildup) in real time if necessary. This definitely provides an enhanced data interpretation that can be used for resevoir evaluation specially for secondary recovery projects.
Ramos Field: Feasibility of Gas Cycling, An Integration of Geology and Engineering
Authors: Graue D. J. , Larsen W. 
Published: December 2007

Abstract
A study of the geology, the pressure data, and transient pressure tests from the Ramos Field in Northern Argentina suggest that the reserve of gas-in-place is probably 100× 109 standard cubic meters. However, the gas is probably not contained in the Santa Rosa sandstone formation from which it is produced. Rather it is probably contained in the shale zones which overlie and underlie this formation. The fracture system throughout the Santa Rosa sandstone is the conduit through which the gas is carried from the shales to the wells.
If this analysis is correct it means that any injected dry gas into the wells in the field will cycle very rapidly to the producers, because the pore volume of the fracture system is only a small fraction of the volume containing the gas. The available data indicate that the fracture system contains between .01 and .001 of the total gas indicated by a plot of P/Z versus the volume produced. The evidence is sufficient to caution the operator regarding the implementation of a dry gas cycling scheme which might be used to speed the recovery of the liquids contained in the gas condensate.
Oil Reservoir Sandstone Evaluation with Digital Backscattered Electron Images
Authors: Alvarado V. , Guzman J. , Kancev I. 
Published: December 2007

Abstract
Mineralogical and pore characterization has become an important key when evaluating oil reservoir quality. Presence of diagenetic or secondary mineral such as clays and cementing material can modify rock's texture, affecting in many cases the porosity and permeability during production and EOR processes.
Scanning electron microscopy (SEM) and other related techniques have been widely used in petroleum industry to study and characterize sedimentary rocks.
Backscattered electron (BSE) detectors and X-ray analysers are tools generally associated with SEM instruments, used by petrographers and petrophysicists who have taken a deeper concern with rock porous media (texture and mineralogy) through micrographies (analog signal) and its processing (digital signal). Relation between mineral composition and gray tone in the original signal, results on what could be called BSE imaging technique which shows some advantages over conventional techniques.
Core samples from Venezuela western region have been evaluated by BSEI. Micrographies from a SEM, working in the BSE mode were digitized and processed whith PDIFRAC software which was developed for this purpose.
Mineral and porosity fractions of the cores are presented for different depths. These results are compared with results obtained previously by XRD, IR and thin section petrography on the same samples.
Images are used to provide mineralogical composition, porosity maps, fractal dimention calculations and to visualize potential cases of formation damage by fines migration (kaolinite and pyrite fines)
Determination of True Resistivity (Rt) in Thin Beds Using Microresistivity Logs
Authors: Quintero L. F. , Ramirez M. O. 
Published: December 2007

Abstract
An algorithm for the determination of the true resistivity of thin beds (Rt) has been derived. The algorithm has been obtained using the deep resistivity curve and the microresistivity log. Numerical data modelling corroborate results. A smart computer program provides (with no need of programming skills) a user friendly interface.
X-Ray Tomography Application in Porous Media Evaluation
Authors: Angulo R. , Ortiz N. 
Published: December 2007

Abstract
With the development of a simple and more adequate macroscopic functional representation for the attenuation coefficient, more accurate quantitative and semiquantitative analysis can be made on X-ray tomography data. Numerical as well as visual information can be generated on the description of the phenomena occurring within the porous media. This work presents the results of analysis and numerical modeling of tomography data where a polynomial representation is used to estimate the attenuation coefficient. In addition, its application to the analysis of porous media and substances that are normally found in oil reservoirs is considered.
A polynomial representation is used for estimating the density and average atomic number of the substances occupying a volume element. These properties are also displayed for a better analysis of the system under consideration,
Characterization of an Oil Segregated Column, El Furrial Field
Authors: Alvarez R. , Marcano D. 
Published: December 2007

ABSTRACT
The El Furrial field is located in Monaqas State, eastern Venezuela. It was discovered in February 1986 with the drillinq and completion of well FUL-1 in the sandstone of the Naricual formation, which resulted in an initial production of over 7200 bpd of oil with a gravity of 29 °API and a 1/2" choke.
The results of an intensive assessment plan led to the identification of reservoirs with average sand thicknesses of 1200 feet, original oil in place of over 4,000 MMBBL and a complex fluids system arising from a segregation process of asphaltic components. The crude's API gravity varies from 29 °API at the top of the structure to a layer of bitumen (8 °API) at its base, which prevents any natural water flooding process.
The purpose of this paper is to chemically and thermodynamically characterize the fluid column in the El Furrial field. The peculiar PVT behaviour of the column and the way in which its chemical and thermodynamic properties can be identified through the API gravity figures are described. The methodology used to identify the various zones of fluids in the field and to characterize a transition zone approximately 350 feet thick is also described.
Interpretation of Miscible Displacement Experiments Using Solutions in Laplace Space and Deconvolution
Authors: Portella Ricardo C. M. , Corrêa Antonio Cláudio F. 
Published: December 2007

Abstract
This paper presents a new methodology to interpret miscible displacement experiments. From the monitoring and analysis of effluent tracer concentration in laboratory cores it has been possible to determine the parameters which characterize the porous media and the displacement process.
Miscible displacement models of tracer transport in both homogeneous and heterogeneous porous media have been considered. The three-parameter models for heterogeneous porous media have been solved by numerically inverting solutions obtained in Laplace domain. The numerical inversion has been carried by Crump's algorithm, which yields solutions virtually free of numerical dispersion.
The methodology consists initially of the analysis of the effluent concentration data obtained from one-dimensional tracer injection experiments, by simple graphical methods. The results of the graphical interpretation are then used as initial estimates of the model parameters in an automated curve fitting process.
Application of graphical analysis is only possible in continuous (step) injection experiments. For experiments consisting of injection of a tracer slug, the effluent composition data are deconvolved. The deconvolution process yields the equivalent effluent composition data that would have been obtained from a continuous injection experiment, thus allowing the application of graphical analysis.
An experimental apparatus has been constructed and a series of experiments have been made. Experimental results have been analized with the new interpretation methodology.
The combination of graphical and automated curve fitting analysis has proved to be fast and reliable, and can be employed in on-line experiments.
Automation of Pressure Transient Test in Laboratory Using Deconvolution
Authors: Orellana Enrique Noel , Corrêa Antonio Cláudio F. 
Published: December 2007

ABSTRACT
This work explores the application of automated pressure transient test analysis and deconvolution technique in laboratory scale.
To achieve this, a linear core which provides a pressure response corresponding to predetermined mathematical models, has been constructed.
The pressure response to applied boundary conditions has been monitored in real-time by means of an A/D converter installed in a microcomputer. Applying specific analysis techniques, permeability (k) and compressibility-porosity product (ϕ·ct) can be obtained from experimental data.
Data analysis includes: deconvolution of accumulated production and pressure responses, i.e. the desuperposition of a variable boundary condition;least squares non-linear estimation of system parameters. Greenstadt's modification of classical Newton's method has been selected to perform parameters optimization.
In order to be a reference to related future experiments, practical aspects and problems associated with the materialization of this experiment, specially those related with the interface between physical experiment and computer techniques, are extensively detailed in this work1.
A Brownian Method for Obtaining the Areal Continuous Distribution of Oil Reservoir Parameters
Authors: Martínez R. 
Published: December 2007

ABSTRACT
A method for obtaining the continuous areal distribution of oil parameters (porosity, water saturation, etc.) of heterogenous oil reservoirs is presented. For its application it requires the previous knowledge of a set of discret values z(k,l). The theoretical fundamental assumption of the proposed method etablishes that all natural distributions can be considered as the superposition of each elementary brownian distribution, represented by its discret value z(k,l), whose physical model is the diffusion differential equation and its solution. This is a technique that allows the representation of brownian random distributions as a linear combination of each elementary diffusion function. For illustrating the operational aspect of brownian analysis, four examples are presented. The resultats are presented as digital images by means of image processing techniques. This method can be applied in mapping, two dimensions interpolation, numeric simulation and reserves calculation.
lmbibition as a Dispersion Process
Authors: Hernández J. Cruz , Rosales C. Pérez 
Published: December 2007

ABSTRACT
In waterflooding operations in fractured reservoirs, imbibition is an important mechanism for expelling oil from the rock matrix. Therefore, a detail knowledge of imbibition processes is necessary for improving oil recovery. Here a theoretical-experimental work concerning this subject is described. In the theoretical part of the work, an analytical model is developed. This model is based on the assumption that imbibition can be visualized as a diffusion phenomenon. Some experiments carried out with Berea sandstone samples validate the model.
A Comparison of Deepwater Sand Control Practices in the Gulf of Mexico
Authors: Fahel R. A. , Brienen J. W. 
Published: December 2007

Abstract
Several published articles mention sand control problems in deep water Gulf of Mexico projects. ‘ In the Fall of 1990 Oryx Energy, while preparing for a deep water platform decision, conducted an in-depth study of deep water sand control techniques. At the time of the study, there were eleven platforms in water deeper than 700′ and they were operated by six companies. Each company permitted an interview with their engineers. This allowed us to trace the history of these platforms from conception through current operations, with special emphasis on sand control. This paper presents the specific techniques for wellbore preparation, perforating, stimulation, gravel packing, and completion hardware used by these six companies (companies only identified as A through F).
Sediment Alteration and Fines Migration in Enhanced Recovery Operations, Tertiary Heavy Oil Fields, California
Authors: Barrett M. L. , Mathias R. W. 
Published: December 2007

Abstract
California heavy-oil sands are very similar in alteration patterns during thermal recovery processes. Hot-water and steam reactions (up to 200°C) result in additional smectite and zeolite growth. These reactions alone do not predict the permeability decrease. As in sedimentary diagenesis, grain size allows a better understanding of permeability decreases and fines migration patterns. Finer-grained sediments have a greater order-of-magnitude permeability decrease to injected fluids as compared to coarser sediments. In-situ combustion reactions are much higher temperatures {500+ °C), but inter-well sediment alteration is limited to the matrix. This contrasts with samples from a combustion air injector, where both metamorphic fabrics and minerals were present.
Analysis of Gravel Packing Using 3-D Numerical Simulation
Authors: Nguyen P. D. , Fitzpatrick H. J. , Woodbridge G. A. , Reidenbach V. G. 
Published: December 2007

Abstract
Numerical simulators have proven to be viable tools for studying dynamic systems and providing accurate predictions. When combined with the advanced capability of modern computers, the flexibility of the numerical approach allows a wide array of variables to be investigated that otherwise would be limited by time, safety, or cost. Previous attempts at simulating gravel packing have yielded less than desirable results. This paper provides a comprehensive review of previous models and describes the mathematical development of a full scale, three-dimensional, gravel pack simulator.
Formation Damage Control During Underreaming and Gravel Packing in an Overpressured Reservoir
Authors: Blanton R. J. 
Published: December 2007

Abstract
Performing an underreamed gravel pack in a hot, overpressured reservoir is difficult. Underreaming fluid must be non-damaging, provide hole stability and cleaning, and generate a filter cake that can be removed. The gravel pack must be designed to minimize filter cake removal and gravel/formation sand intermixing. Successful underreamed gravel packs have been accomplished in normal pressure environments, but they have not been attempted in overpressured environments because of the associated difficulties.
This paper describes: 1) Displacement procedures used to clean the casing and protect the open hole, 2) Non-damaging underreaming fluid system which meets drilling and completion requirements, 3) Gravel pack design that minimizes gravel/formation sand intermixing, 4) Post gravel pack acid stimulation to remove the underreaming-fluid filter cake, 5) Gravel pack log, and 6) Well performance.
Hydraulic Fracturing of Soft Formations in The Gulf Coast
Authors: Ayoub J. A. , Kirksey J. M. , Malone B. P. , Norman W. D. 
Published: December 2007

Abstract
This paper discusses hydraulic fracturing treatments for unconsolidated sand reservoirs. The procedures needed for selecting the appropriate candidate wells, designing successful treatments, executing them and evaluating the results, are presented in a format directly usable by the practicing engineer. Field examples illustrate some of the key techniques.
Examining the Phase Behavior and Retention Characteristics of Binary Inhibitor Agents for Scale Control
Authors: Lawless T. A. , Bourne H. M. 
Published: December 2007

Abstract
The prediction and optimisation of scale inhibitor squeeze treatments demands careful attention to both aqueous phase behaviour and the resulting retention mechanisms in consolidated core material. Phase behaviour patterns for single and binary systems of acrylate and phosphonate scale inhibitors in sea water have been generated over a range of pH values and concentrations appropriate to flooding and field conditions. The phase maps were utilised to define coreflooding strategies that would yield separate adsorption and precipitation retention mechanisms for detailed study under a controlled pH environment.
Retention and desorption characteristics of the single component inhibitor agents were performed at 80°C on Clashach sandstone core specimens in both adsorption and precipitation regimes where possible. Return curve analyses were quantified using inductively coupled plasma spectroscopy and an analytical colourimetric method for the phosphonate and acrylate respectively. Desorption profiles have been fitted to mathematical expressions and the physical significance of the models used have been interrogated.
Binary inhibitor systems capable of yielding both adsorption and precipitation phase behaviour at 80°C were selected for test purposes to establish the prevailing retention mechanisms of both agents in competition. Separate desorption profiles for each inhibitor following a binary system shut-in were generated. The role and suitability of simple mathematical models to aid the interpretation and impact for future formulations has been addressed.
Damage Caused by Clay-Based and Clay-Free Inhibitive Fluids in Sandstone Formations
Authors: Ghofrani Reza , Alaboudi M. A. Mazeel , Sengupta Pinaki 
Published: December 2007

Abstract
This paper describes the results of a research project about the extent of damage caused by clay based and clay free inhibitive fluids in two consolidated sandstones of permeability ranges 0.008-0.013 μm2(D) and 2.2-2.6 μm2(D) under simulated borehole conditions, using a closed loop circulating facility.
The fluids containing K+, Mg++ or Ca++ ions as well as clays, solid bridging materials and different polymers can be used either as drilling fluids or as workover, fracture and gravel pack fluids.
The damage was studied by two factors, viz, damage ratio DR (Percentage of original permeability lost after encountering the fluids) and sectional damage ratio SDR (Determined by cutting the damaged core into several segments and then determining the damage ratio of each segment relative to the original permeability of the core). The sectional damage ratio is used to determine the radius and extent of damage in the formation.
The dynamic filtration characteristics and the rheological properties of the used fluids were also evaluated.
The effects of increasing the temperature and differential pressure on formation damage and filtration characteristics of the used fluids were also investigated.
The effect of the presence of formation pore bridging materials (viz, chalk) in decreasing the extent of damage is also demonstrated here.
Alternatives to Aromatics for Solvency of Organic Deposits
Authors: Samuelson M. L. 
Published: December 2007

Abstract
This paper describes laboratory investigation of alternate solvent systems and their application to the removal of organic deposits. Aromatic solvents, such as toluene and xylene, have been popular remedies for near-wellbore cleanup operations. Stricter regulations governing disposal, volatile-emission limits, and flammability/handling concerns have made the use of toluene and xylene less attractive. In an effort to limit environmental and personal exposure hazards, alternate solvents have been investigated.
Theoretical solvency parameter comparisons linked with a data base search was used to initially screen alternate solvent systems. Quantitative paraffin and pipe-dope solvency tests, along with asphaltene stability titrations, were used to qualify potential solvent candidates. As a result of this work, several alternative solvents have been found which fall outside the regulatory restrictions for xylene and toluene, while maintaining effective removal of paraffin, asphaltene and pipe-dope deposits.
Successful Stimulation of Acid-Sensitive Crude Producers in the Gulf of Mexico
Authors: Picou R. A. , Ricketts Kevin , Luquette Mary , Hudson L. M. 
Published: December 2007

Abstract
This paper presents a case history of successful acid stimulation treatments on acid sensitive crude producers in the Gulf of Mexico at Main Pass 313 field. It shows how catastrophic emulsion and facility upset problems encountered during the flowback of the first well in a multi-well stimulation program were resolved and used as the basis for optimizing treatment design on the remaining wells. Overall, it demonstrates how taking a preventative posture through a total system approach to the stimulation process was the key to solving the acid treatment flowback problems experienced.
Formation Damage Due to Static and Dynamic Filtration of Water-Based Muds
Authors: Jiao Di , Sharma M. M. 
Published: December 2007

Abstract
A series of drilling mud invasion experiments were conducted on Berea sandstone cores to measure the extent and depth of formation damage by mud filtrates and mud particles. A specially designed dynamic filtration core holder was used in this study. Pressure taps along the core holder allowed us to measure the permeabilities for 3 sections of the core while circulating mud. Seven kinds of muds with different salinities and different dynamic filtration rates were circulated across the face of the core for 10 hours. After mud circulation, return permeabilities for brine and oil were measured. The effect of bentonite concentration, the effective particle size, degree of flocculation, polymer additive concentration, and oil saturation in the core were shown to influence the extent of formation damage.
Quantitative Analysis of Bulk Mineralogy: The Applicability and Performance of XRD and FTIR
Authors: Ruessink B. H. , Harville D. G. 
Published: December 2007

Abstract
Understanding the limitations and sensitivity of various techniques for quantifying mineral composition is essential for enhanced control of formation damage, e.g. in selecting a completion fluid and/or acid formulation.
This paper presents the results of a systematic evaluation of the reliability, applicability and intrinsic accuracy of the two most commonly used analytical techniques for quantitative mineral analysis: X-ray diffraction (XRD) and Fourier Transform Infra-Red (FTIR) spectroscopy. The strengths and weaknesses of each technique are related to the different scales of investigation (structural vs. molecular). The analytical accuracies of the techniques are assessed by analysing synthetic mixtures of common rock-forming minerals.
The two techniques were found to have comparable accuracies in analysing bulk mineralogy. For both techniques 90 % of the analyses of synthetic mixtures fell within 5 wt% from the actual concentrations. The results of reservoir core material were consistent with these findings. Costs and turnaround time favour FTIR. The two techniques may be used in combination to supply complementary mineralogical information on complex formations.