bluuebunny/crossref_metadata_2025_split huggingface dataset:
Fast Computation of Effective Properties for Two Phase Flow Problems
Authors: Nomura M. 
Published: December 2007

Abstract
The current requirement of geologic detail to be built into reservoir descriptions has been exceeding the computational capabilities of reservoir simulation due to a need of huge number of simulation grids. This has motivated the development of a variety of upscaling techniques for flow simulation.
This paper presents an efficient upscaling method effective for an oil-wet heterogeneous reservoir, which offers a means of simulating multiple geostatistical realizations. A new effective permeability correlation is developed through application of one of the non-parametric regression techniques to the results of intensive numerical experiments. The developed empirical correlation enables us to compute effective permeabilities fast and accurately for a wide variety of heterogeneous permeability fields from layered to random system and can be easily extended for averaging two-phase flow properties under viscous limit or capillary limit.
The paper describes the developed technique in detail and demonstrates how the overall upscaling procedure can be speeded up with the desired accuracy.
Comparison of Specific Energy Between Drilling With High Power Lasers and Other Drilling Methods
Authors: Graves Ramona M. , Araya Anibal , Gahan Brian C. , Parker Richard A. 
Published: December 2007

Abstract
Specific energy is often used as a measure of a drilling methods performance. Specific energy as defined in this paper is the amount of energy required to remove a given volume of rock (energy/volume). This is a normalization method used to compare the efficiency of one rock destruction technique to another. This paper compares specific energy between drilling with high power lasers and other drilling techniques such as traditional rotary and other novel methods such as water jets.
Specific energy calculations made from laboratory measurements taken using four high power lasers, are compared to specific energy calculations reported in the literature. Although many other rock types were lased in this research, all comparisons are made on Berea sandstone, as it is the most commonly tested rock. A discussion of how the sample type, shape of test sample, and experimental conditions effect the calculations and results is included.
It was found that there could be, and probably is, confusion caused by the way that specific energy is defined and calculated. The definition of specific energy, as used in this paper, is often compared to specific kerfing energy that is defined as power per kerf depth multiplied by the speed the cutting mechanism is moving across a rock surface. It was also found, by reviewing published work, that there have been many comparisons made in the literature that did not take into consideration such things as rock type and shape. Experimental conditions such as the atmosphere where the "cutting" tool and the rock interact have not been accounted for when many of the previous comparisons were made. Sample size in relationship to power density has also not been accounted for.
Fateh Field Sea Water Injection - Water Treatment, Corrosion, And Scale Control
Authors: Nassivera M. , Essel A. 
Published: December 2007

Introduction
In May 1974, Dubai Petroleum Company started the injection of seawater in the Fateh Mishrif reservoir. Hereafter is described the water treatment, the corrosion control through the waterflood plant and the subsea water lines, the scale prevention in the injection wells and the prevention in the injection wells and the scale control in the producing wells.

WATER TREATMENT
The seawater is lifted from 100' below the surface through a lifting caisson common to three lifting pumps. Two electro-chlorinators provide a hypochlorite solution in order to kill the bacteria and marine organisms in the lifted water. The hypochlorite solution is injected through a distribution ring located at the bottom of the lifting caisson, therefore all the lifted water is treated. The electro-chlorinators can be operated either automatically or manually to insure a chlorine content of 1 to 1.2 mg/l in the lifted water.
The average total suspended solids (T.S.S.) in the raw water is 1 mg/l with a maximum of 4 to 5 mg/l. From the caisson, the water goes through strainers then to the upflow sand filters. Before entering the filters a coagulant is injected into the water. The injection of bentonite as a filter aid was found unnecessary and has been discontinued. After filtration the TSS is less than the specified 0.2 mg/l. The TSS is determined by filtration on a 0.45 millipore filter. To meet the TSS specification the filters are flushed every 48 or 72 hours according to the raw water TSS.
A defoamer is added to the water before entering the vacuum towers where the water is deaerated by vacuum. The remaining oxygen content is less than 0.02 mg/l. Since the water injection was started it has never been necessary to add an oxygen scavenger to meet the specified oxygen content of 0.02 mg/l. The filtered deaerated seawater is then injected in the Fateh Mishrif reservoir through 24 wells. Once a week a bactericide is injected as a batch treatment upstream of the sand filters to kill the remaining bacteria. Two different bactericides are used alternatively.
The oxygen content of the water is monitored continuously. The iron, hydrogen sulfide and sulfate reducing bacteria contents are regularly monitored on the waterflood plant and on the remote platforms to determine adjustments necessary in the water treatment.

CORROSION
The raw seawater contains an average of 6.5 mg/l of oxygen, 42 to 44,000 mg/l of dissolved salts and has a low resistivity of 17.60 ohm-cms; therefore it is very corrosive. The lifting caissons, the strainer bodies and the lifting pump discharge headers are made of epoxy lined carbon steel. The lifting pumps are composed of stainless steel and monel which are corrosion resistant. From the discharge header to the vacuum towers, vinyl ester resin fiberglass reinforced piping has been used successfully.
The vacuum towers are lined with rubber. Downstream of the vacuum towers the oxygen content of the water is less than or equal to 0.02 mg/l.
Active Feedback Control of Unstable Wells at the Brage Field
Authors: Dalsmo M. , Halvorsen E. , Slupphaug O. 
Published: December 2007

Abstract
In this paper we will present new results on stabilization of horizontal wells with gas lift. The stabilization is achieved by a novel dynamic feedback control solution using the production choke at the wellhead. The primary input to the dynamic feedback controller is a measurement of the downhole pressure.
The field results to be presented are from the Brage field operated by Norsk Hydro in the North sea. Production at Brage began in 1993 and the field went off plateau in 1998. As the production has decreased, the problems related to unstable production from some of the wells have escalated steadily.
The results from the extensive field tests on the Brage wells are very promising. The tests have confirmed the stabilization feature of the control solution. The pressure and flow variations have been dramatically reduced, and it is possible to produce the wells at a lower downhole pressure leading to increased production.
Downhole Fiber-Optic Multiphase Flowmeter: Field Installation
Authors: Kragas Tor K. , Myers Gregory A. , Purdy Gill E. , Dria Dennis E. , Rambow Frederick H. 
Published: December 2007

Abstract
In October of 2000, a downhole fiber optic flowmeter was installed in Shell's Mars A-18 well in deepwater Gulf of Mexico. The production tubing-deployed system was installed to a measured depth of 21,138 feet in a highly deviated section of the well, immediately above the producing zones, in 2940 feet of water. This installation represents the first allfiber optic, multiphase flowmeter system deployed in a commercial well.
The fiber optic flowmeter delivers real-time measurements of downhole pressure, temperature, flow rate, and phase fraction. It is completely non-intrusive and contains no downhole electronics or moving parts. The meter requires only one wellhead penetration and is deployed on a single fiber optic cable with the production tubing string during well completion, in a manner similar to conventional, electronic downhole monitoring systems. Installation of the flowmeter at Mars was achieved as planned with no additional rig time required. In fact, the entire well completion operation was finished ahead of the budgeted schedule. This in large part is attributable to pre-job planning and preparations for the entire operation.
Performance of the flowmeter at Mars exceeded expectations and demonstrates the value of real-time downhole production data. Along with providing the production engineer with downhole pressure and flow rate data to control draw down while the well was being ramped up, data from the flowmeter provided other valuable information such as a temperature and pressure profile of the well during run-in-hole, well behavior during cleanup, and well productivity data.
A Case Study: Field Development Plan for a Highly Overpressured Gas Reservoir in China by a Multidisciplinary Consulting Team
Authors: Li Haiping , Xiong Hongjie , Wang James , Broetz Rolf J. , Azoba Hilary , Ryer Thomas A. , Miller Gary D. , Rahn Tami Chism , Wiltgen Nicholas A. , Robinson Brad M. , Kugler Ralph L. , Lee Donald W. , Plumb Richard A. , Martin Ron , Spivey John , Sun Longde , Song Wenjie 
Published: December 2007

Abstract
Operating companies generally produce their own field development plans (FDPs). Schlumberger Data and Consulting Services, a consulting group within an oilfield services company, was hired by PetroChina to perform a multidisciplinary integrated study on a highly overpressured gas reservoir, the Kela 2 field in the Tarim basin. The field has reserves exceeding 10 Tcf and will provide much of the gas for a major pipeline crossing China from the Tarim basin to Shanghai. The study consisted of building comprehensive geologic and reservoir models, estimating reserves, performing dynamic production and performance analyses on the reservoir, and providing an optimal FDP, which includes the drilling and completion designs, production engineering, reservoir monitoring and management, optimal implementation methods, and best practices.
This paper describes a comprehensive FDP technical approach and workflow designed to ensure both seamless integration of the disciplines and high-quality work. The technical approach incorporates the construction of a database, geological reservoir and mechanical earth models, a reservoir dynamic model, a single-well model, a development design model, and an economics and risk model. The paper summarizes our experience in assembling a multidisciplinary team, promoting effective teamwork, and quality control (QC).
Harmonic Testing for Continuous Well and Reservoir Monitoring
Authors: Hollaender Florian , Hammond Paul S. , Gringarten Alain C. 
Published: December 2007

Abstract
Harmonic testing for obtaining dynamic reservoir information was first proposed some thirty years ago. Although not much used in the oil industry, interest in the method is revived periodically, mostly for the determination of skin effect and near-wellbore permeability.
This paper looks at the practical aspects of using periodic rate variations for testing oil wells. It is shown that such tests can provide the same information as conventional well tests and can be interpreted in the same way. Their main advantage is that they do not require fluids to be brought to surface in exploration or early appraisal testing, or wells to be shut-in in production testing. They also provide data that are less affected by measurement errors and wellbore effects such as multiphase flow or phase redistribution. The main limitation is that, for the same radius of investigation, harmonic tests are significantly longer than conventional tests. Consequently, they cannot be used for reservoir characterization in exploration and appraisal wells. They appear well suited, however, for monitoring reservoir changes from production wells.
A Model for Foam Generation in Homogeneous Media
Authors: Kam S. I. , Rossen W. R. 
Published: December 2007

Abstract
Foam is a promising means to reduce gas influx into oil wells, control gas flow in improved oil recovery processes, direct acid flow in matrix acid well treatments, and improve the efficiency of environmental-remediation processes. Recent laboratory research in a wide range of porous media shows that creating foam in steady flow in homogeneous media requires exceeding a minimum pressure gradient. Data fit trends predicted by a theory in which foam generation depends on attaining sufficient ∇p to mobilize liquid lenses present before foam generation. Data show three regimes: a coarse-foam regime at low ∇p, strong foam at high ∇p, and, in between, an transient regime alternating between weaker and stronger foam.
Here for the first time a population-balance foam model incorporates bubble-creation function that depends on pressure gradient. The new model reproduces the three foam regimes seen in the laboratory, the abrupt occurrence of foam generation at a threshold velocity or pressure gradient, hysteresis in experimental results, the interplay between foam stability and foam generation, the effect of injected liquid fractional flow on foam generation, and foam behavior in the high-quality and low-quality steady-state strong-foam regimes. The details of the lamella-creation function have little effect on rheology of strong foam, which is controlled by other mechanisms. The predicted fractional-flow curves are complex. This model is a necessary step toward quantitative prediction of foam performance in the field.
Simulating Foam Process for a Venezuelan Pilot Test
Authors: Chalbaud C. A. , Moreno R. A. , Alvarez J. M. 
Published: December 2007

Abstract
Foams have been used routinely worldwide to divert acid in well stimulation treatments and to divert gas flow in improved-oil-recovery projects. However, the complexity of foam behavior has represented a strong obstacle in understanding and modeling such processes.
In 1999 Alvarez et al1 proposed an unified model for steady-state foam behavior at high and low qualities called "fg* model". This model explains the presence of two different foam-flow regimes identified by Osterloh and Jante2 in 1992. The fg* model is based on experimental laboratory data at room temperature.
The present study shows experimental data confirming that fg* model also applies at reservoir conditions (temperature, pressure and permeability close to the field). This fact has never been reported before. The experiments were designed to characterize steady-state nitrogen foam flow by measuring pressure gradients in Berea sandstone over a wide range of gas and liquid velocities and fractional flows. This study also presents the assumption that the critical surfactant concentration exists, below which the foam becomes weaker or unstable32. This critical variable was determined at reservoir conditions.
The experimental data were used to validate the foam model using a commercial simulator (STARS™), taking into account the parameters related to surfactant concentration, water saturation, capillary number and the reference mobility reduction factor. This simulation is used as part of the planning of a future pilot test in the Lagocinco field in the Maracaibo Lake, Venezuela.
Experimental work, such as that presented in this paper, gives support to the fg* model and allows choosing in advance, optimal foam treatment conditions (e.g. surfactant concentration and foam quality) for a particular gas diversion project, obtaining a more cost-effective field operations and determining the viability of a gas or acid diversion project.
Accurate Full-Bore Acoustic Densometer for Use with Proppant-Laden Stimulation Fluids at High Pressures
Authors: Birchak James R. , Vickery Curtis M. , Morgan Ronnie G. 
Published: December 2007

Abstract
Some areas of the globe with high oil and gas well drilling activity do not permit surface equipment that contains any type of radioactive source. The continuing concern with using radioactive sources in oilfield service equipment has led to the development of a new design for an acoustic densometer that will function accurately under the conditions required by stimulation pumping operations. Accurate metering of fluids containing high concentrations of materials such as frac sand, ceramic proppants, or other solids are an integral part of successful stimulation treatments of oil and gas wells around the world. Previous designs of acoustic densometers were not satisfactory for use at high pressures or were eroded excessively by the solids-laden fluids employed in hydraulic fracturing operations.
This new densometer design is able to handle full-bore flow at high pressures and to meet or exceed the accuracies of current in-line radioactive (R/A) densometers. In the paper, we will discuss the technical approach used to make the measurements. Extensive full scale test data will be shown for comparisons using three sand sizes (12/20, 16/30, and 20/40) in a water based gelled fluid with proppant concentrations of zero (no sand) up to 14 lb sand added per gallon.
A Method for Computing Fast and Accurate Analytical Gradient: the Key for Routinely Performing Efficient 2D and 3D Resistivity Inversions
Authors: Terpolilli P. , Ventre J. , Touron F. , Ramos I. 
Published: December 2007

Abstract
This paper consider several issues related to the inversion of resistivity log curves.
After choosing an initial guess, the inversion process needs to know exactly how to modify the earth resistivity map in order to obtain better computed curves. If we define the cost function as the square of the norm of the difference between the computed and the measured curves, the gradient map provides this piece of information. Only an analytical determination of this gradient map is efficient enough for an accurate solution. However, the additional computing time has to be reasonable. This paper includes an original method to determine an accurate first guess and a new method to compute efficiently the gradient of the cost function. Some numerical figures in CPU time are given for the computation of the gradient and for sensitivity analysis as well..
A Case Study of Long-Term Production Enhancement Derived from Usage of Organo-Borate Crosslinked Fracturing Fluids
Authors: Wood William D. , Brannon Harold D. , Ault Marshall G. , Matson Ronald P. , Carman Paul S. 
Published: December 2007

Abstract
Over the past 12 years, a significant number of wells in fields across the United States have been fracture stimulated with advanced organo-borate crosslinked fluids. This case study examines the production enhancement benefits that have been realized, as compared to more conventionally treated offset wells. Conventional treatments are defined as treatments that may consist of mono-borate or organo-metallic crosslinked fluids. Several case histories and offset comparisons were presented in the original SPE Paper 22838. This paper will provide a 10-year follow-up of those wells, presenting their long-term production benefits acquired from the use of organo-borate crosslinked fluids. In addition to the presented case histories from two subsequent SPE Papers, production data from an available pool of over 4000 wells, existing in numerous fields throughout the U.S.' and dating back to 1996, was analyzed and compared to offsets using conventional fluids. Selected examples from this analysis will be examined, and field data utilized to accomplish this study will also be discussed.
Application of the organo-borate crosslink mechanism in fracturing operations improves long-term production by a number of methods. More complete break profiles may be obtained with an organo-borate fluid than conventional fluids because of the chemical formulation of the crosslinker itself. This break profile contributes to better long-term fracture performance by improving conductivity nearer the fracture tip, extending the effective fracture length over conventional fluids. Consequently, the long-term production benefits are improved, as more reservoir area is available to make a contribution. The organo-borate crosslinker technology also contributes to improve fracturing dynamics, as it delivers significantly higher in-situ viscosity development than conventional fluids. This viscosity development improves fracture generation capabilities, reduces tortuosity concerns, and places proppant more effectively than conventional fluids. Organo-borate crosslinker technology also dramatically improves the temperature stability of a fracturing fluid compared to a conventional mono-borate.
A Novel Approach for Enhancing Proppant Consolidation: Laboratory Testing and Field Applications
Authors: Nguyen P. D. , Weaver J. D. , Parker M. , McCabe M. , Hoogteijling M. , van der Horst M. J. 
Published: December 2007

Abstract
Curable resins have been used to coat onto proppant for controlling proppant flowback after hydraulic fracturing treatments as well as in screenless, frac pack completions. As more wells are drilled into deeper reservoirs, severe conditions including high temperatures and high production flow rates impose more constraint requirements on the use of curable resin systems. This paper presents the results of an extensive study, both laboratory and field testing, of a new liquid resin coating system that is particularly useful in controlling proppant flowback in high-temperature, high-flow rate wells. Additives included in the liquid resin system eliminate fracturing fluid interference and permit good consolidation properties to be achieved without any formation closure stress.
Results of this work demonstrate the difficulty in designing fracturing treatments such that the curing of resin does not occur too fast relative to fracture treatment time and the time for formation closure to achieve good consolidation, but fast enough to prevent flowback upon fluid recovery operations. The useful window for resin-coated proppants has been greatly expanded by the incorporation of simple chemical additives into the resin that react with fracturing fluids, rendering them noninterfering to the consolidation process. These additives permit resin-coated proppant to achieve good consolidation properties without closure stress.
This study provides new answers as to why resin-precoated proppant (RCP) consolidations sometimes fail in the field. Operators can use the information presented to help them select the appropriate curable resin systems for their applications where consolidations are expected to withstand production conditions of high temperatures, high flow rates, and stress loading.
Temperature effects in Brazilian, uniaxial and triaxial compressive tests with high porosity chalk
Authors: Madland Merete Vadla , Korsnes Reidar Inge , Risnes Rasmus 
Published: December 2007

Abstract
The objective of the present project was to study how high temperatures affect the different mechanical parameters of chalks. Two types of high porosity outcrop chalks were used. Several series of Brazilian, uniaxial and triaxial compressive tests have been performed at both ambient and reservoir temperature, 130 °C the Ekofisk temperature. Both water and glycol were used as saturating fluids, and in addition some test series on dry chalk were included. The results so far show that the yield envelope has a tendency to shrink with increasing temperature. Both cohesion and the hydrostatic yield stress are typically reduced about 20 % in going from 20 to 130 °C, but the magnitude of this reduction may be chalk type dependent. For the friction angle there are some indications of a slight increase with increasing temperature, but some results point in the opposite direction. Experiments with dry chalk show some degree of strengthening, probably due to drying effects.