bluuebunny/crossref_metadata_2025_split huggingface dataset:
Optimization Design for Conformance Control Based on Profile Modification Treatments of Multiple Injectors in a Reservoir
Authors: Liu Y. Z. , Bai B. , Li Y. X. , Coste J-P. , Guo X. H. 
Published: December 2007

Abstract
Within the past 40 years, profile modification has been widely used in China to control excess water production and improve waterflood sweep efficiency. As most reservoirs reach mature stage, single well treatment often becomes uneconomic. Therefore, profile modification treatments of multiple injectors based on reservoir scale have been applied to improve reservoir conformance. In this paper, a method is introduced to optimize the design of the treatment. The selection of the wells and target layers, as well as the chemical agent and injection parameters can be achieved by this method. The selection of candidate wells is based on fuzzy mathematics methods, considering well injectivity, reservoir heterogeneity and offset production well performance. The chemical agent is selected from over 40 formula commonly used in China, according to its compatibility with reservoir characteristics and well injectivity. The volume of treatment is optimized by running numerical simulations. This optimization method has been widely used in many oilfields in China. In most cases, production analysis after treatment shows that the waterflood efficiency is improved, and that the model predictions match well with the actual production data. As an example, a detailed analysis of the treatment performed in the Long 11 fault-block reservoir in Qing Long Tai oilfield is given in the paper.
High-Energy Perforation and Fracturing (HEPF)----Great Revolution of Perforation for 21st Century
Authors: Zhang Tinghan , Zhang Xi , Li Ning , Li Kuan 
Published: December 2007

Abstract
Based on the snalysis of 50-year-long experiences of conventional perforation, this paper presents an innovative perforation techique that two different types of high energy-shaped charge and propellant are being put inside the gun, and these two types of energy would be ignited at the same time but be put in action separately, therefore perforation and fracturing could be combined perfectly, forming high conductine tunnel-fracturing network and greatly increasing percolation area around near wellbore, Surface concrete target test shows length of semi-radial fracture is 2500mm, More than 700 wells application proved that this technique is safely operating, and greatly increasing production and injection. At present, the comprehensive system of apparatus study and manufacture, surface test, operation art, modern downhole test and intelligent software is being composed, which will make progress and revolutionize international perforation.
Parallel Reservoir Simulation on Shared and Distributed Memory System
Authors: Liu Wei , Cao Jianwen , Mezzatesta Alberto , Zhu Peng 
Published: December 2007

AbstractComputational efficiency is a major subject in large-scale reservoir simulations. Parallel simulation has gained popularity in recent years. Complex geological environments and production management demand new mathematics and science in various computational environments.This paper presented a parallel simulation algorithm and data processing developed for shared and distributed memory systems. The preconditioned Krylov subspace method with hybrid preconditioner based on domain decomposition was constructed to solve the large-scale linear system resulted from black-oil simulator techniques.Based on a fully implicit, three-dimensional, three-phase black-oil reservoir simulator, this project focused on the numerical intensive linear solver. The parallel algorithm is scalable and applicable to both shared and distributed memory systems. Numerical tests were performed on both multi-CPU workstations and PC clusters. A message passing interface (MPI) library was adopted for all message passing functionality in both shared and distributed memory environments. Input/output parallelism and localism are presented in these hardware setups.Numerical results from benchmark models and field application examples are presented for both the multi-CPU SGI Power Challenger and a Linux based Intel PC cluster. Results show that the speedup factor is significant. The simulation performance increases with the number of processors and only decreases due to the limitations introduced by message passing activities.
Development of an Oil-Based Gravel-Pack Carrier Fluid
Authors: Kelkar S. , Parlar M. , Price-Smith C. , Hurst G. , Brady M. , Morris L. 
Published: December 2007

Abstract
Operational problems arise when wells drilled with synthetic/oil-based reservoir drilling fluid (S/OB-RDF) systems are completed using traditional water-based gravel pack carrier fluids. Fluid compatibility, formation wettability and filter cake cleanup have to be addressed, along with the cost of prolonged rig time, for displacements and pit cleaning. There is significant potential for oil-based gravel pack carrier fluids for completing openhole horizontal wells drilled with S/OB-RDFs. Oil-based carrier fluids may minimize compatibility issues, reduce rig time, and provide a means for filter cake cleanup. At a minimum, oil-based gravel pack carrier fluids should:
Carry and suspend gravel at downhole temperatures Provide density up to 13.5 ppg for well control Be compatible with standard oil- and synthetic-based muds and additives.
An oil-based gravel pack carrier fluid with these fluid characteristics has been developed. The fluid system is formulated using a low aromatic base hydrocarbon, a heavy brine formulation (e.g. NaCl, CaCl2, CaBr2, K-formate.) and a surfactant. Results indicate that the fluid system is stable under shear, has good gravel suspension characteristics and has a low formation damage potential. Yard test data demonstrate the feasibility of the fluid system when used in conjunction with shunt screen technology.
Structure and Process Optimization for the Use of a Polymeric Relative-Permeability Modifier in Conformance Control
Authors: Eoff Larry , Dalrymple E. Dwyann , Reddy B. R. , Everett Don 
Published: December 2007

Abstract
For many years, relative-permeability modifiers (RPM's) have received a great deal of attention from the oil- and gas-production industry. Because of the completion techniques used in many wells, it is not always practical or cost-effective to protect the hydrocarbon interval properly during a water-shutoff treatment. RPM's offer the option of bullheading a treatment without zonal isolation, which is designed to decrease water production with little or no decrease in oil or gas production.
This paper describes the laboratory development and optimization of a polymeric RPM. The resulting material can be best described as a brush polymer consisting of a polymeric back-bone grafted with polyethylene oxide (PEO). Various phases of the development will be discussed, such as the optimization of the molecular weight of the backbone polymer and the concentration of grafted PEO. Details of laboratory evaluations will also be provided, including a discussion of the use of multipressure-tap flow cells for permeability-reduction tests, the effect of polymer concentration, and the effect of saturations. These test results show that the RPM polymer should be placed with a systematic approach consisting of proper preflushes and post-flushes for optimum results. Additionally, current theories concerning how RPM's function will be discussed, along with other materials claimed to act as RPM's.
Further Investigations on Two-Phase Flow Property Modification by Polymers: Wettability Effects.
Authors: Elmkies Ph. , Bertin H. , Lasseux D. , Murray M. , Zaitoun A. 
Published: December 2007

Abstract
Adsorption of water-soluble polymers in porous rocks is known to reduce water permeability much more than oil permeability. This effect is often referred to as "Disproportionate Permeability Reduction" (DPR) and can be used in production well treatment to reduce the water cut. This paper deals with nonionic polyacrylamide adsorption on carbonate rocks having different wettability properties. Cores were used first in their native water-wet condition, and after a wettability modification, which was obtained by aging cores saturated with a polar crude oil at 60°C for 6 weeks. Efficiency of the treatment was attested and quantified by strong changes in the wettability index as measured using Amott tests. Drainage and imbibition cycles were performed on these carbonate samples before and after polymer treatment. Polymer adsorption and oil/water relative permeabilities were compared for both media. While the quantity of adsorbed polymer is almost the same on water-wet and on wettability-modified cores, adsorption rates, estimated from viscosity profiles of effluents, are significantly different, suggesting that the polymer slowly restores part of the water-wet character of the native core. All our results indicate that polyacrylamide adsorbs on the rock whatever being the wetting conditions. While disproportionate permeability reduction is always observed, DPR is greater in low-permeability cores.
Productivity Decline of Vertical and Horizontal Wells by Asphaltene Deposition in Petroleum Reservoirs
Authors: Wang Shaojun , Civan Faruk 
Published: December 2007

Abstract
Asphaltene precipitation and deposition models were established and verified by typical experimental data. These models, the porosity and permeability reduction models, and the asphaltene mass balance equation were incorporated into a three-dimensional, three-phase black-oil simulator. Two typical cases involving asphaltene deposition in petroleum reservoirs associated with vertical and horizontal wells were investigated using the simulator. During the three-year period of production, the productivity index declined more than 50 % for both the vertical and horizontal wells. The pattern of asphaltene deposition in the reservoir with a horizontal well was found to be different from that in the reservoir with a vertical well.
Advancements in Paraffin Testing Methodology
Authors: Weispfennig Klaus 
Published: December 2007

Abstract
Predictive methods for wax deposition within pipelines make extensive use of diffusion models to account for the amount of wax being deposited. Laboratory testing methods commonly rely on deposition results from so-called coldfinger devices to assess deposition tendencies. While these experiments are primarily done for testing chemical inhibitor performance, they serve here as the basis for a cross-reference to the often-used diffusion models. An empirical heat transfer model is developed to adequately address the heat transfer within this device. Oil analysis data in combination with thermodynamic prediction routines are used to prepare the necessary n-paraffin solubility charts. While the heat transfer and solubility data are used for a diffusion-type wax deposition, an empirical deposition model is developed to describe the deposition process. It is illustrated how practical information such as deposition tendencies can be gained from these cold finger devices. An assessment of chemical inhibitor performance is made.
Water-Based Muds and Shale Interactions
Authors: Carminati S. , Del Gaudio L. , Del Piero G. , Brignoli M. 
Published: December 2007

Abstract
A simple and robust indentation test has been found to be useful in evaluating shale additive performance, providing results that correlate strongly with those of the much more time-intensive high pressure hollow cylinder tests. This method has been used to evaluate shale inhibitors and many other common drilling fluids additives. Experiments have been carried out with carefully prepared samples of Pierre 2 Shale aged in different formulations. A ranking of shale strength versus mud formulation has been constructed for the following water based fluid additives: glycols (soluble and with Cloud Point), salts (organic and inorganic), gypsum, and polymers (Xanthan Gum, cationic, polyanionic cellulose). Based on the X-ray diffraction pattern analysis of aged shale samples a shape factor has been proposed to identify effective additives.
Laboratory Evaluation of Iron-Control Chemicals for High-Temperature Sour-Gas Wells
Authors: Taylor K. C. , Nasr-El-Din H. A. , Saleem J. A. 
Published: December 2007

Abstract
The objective of this work was to evaluate iron control chemicals used in acidizing systems in high-temperature sour-gas wells.
This work is required because iron compounds that precipitate during acidizing can reduce reservoir permeability in the critical near-wellbore area. Formation damage from fines and precipitated material can be difficult to remove in subsequent remediation treatments.
A high temperature see-through cell was used to investigate the behavior of 28 wt% HCl acid formulae provided by three different service companies. Temperatures up to 300 °F and pressures up to 500 psi were used in this work. This is the first time in the literature that these high acid concentrations have been studied at 300 °F. Previous studies in the industry are available for acid concentrations of up to 15 wt% HCl, temperatures of up to 250 °F, and pressures of 500 psi.
The following conclusions are made:
Nitrilotriacetic acid (NTA) in 28 wt% HCl at 300 °F degrades completely after 5 hours. Therefore, NTA is not effective as an iron control chemical under these conditions. At 250 °F, 77% of the initial NTA remains after 24 hours. It was estimated that the degradation rate of NTA doubles for each 14 °F increase in temperature in the range 250 to 300 °F. Service company acid formulae degrade to produce black precipitates in 28 wt% HCl at 300 °F. These materials contain significant amounts of polyaromatic hydrocarbons and chlorinated aromatics. The acid formulae of two companies oxidize iron (II) to iron (III) at 300 °F in live acids. In spent acid at 300 °F, iron (III) is reduced to iron (II) by all three acid formulae. Both reactions may lead to degradation of acid additives. The acid formula from Company C shows an increase in iron sulfide precipitation in spent acid compared to a control. The acid formulae from Companies A and B show no significant effect on iron sulfide precipitation, when compared to a control. In coreflood tests, iron sulfide precipitates immediately when acid containing dissolved iron (II) and hydrogen sulfide spends on a carbonate rock at high temperature. Iron sulfide accumulates on the injection face, not within the rock itself.
The following recommendations are made:
Reduce total iron concentration in the injected acid to the lowest practical level. Pickle tubing, mixing tanks and lines before the acid treatment. Eliminate the use of NTA at temperatures above 250 °F. Investigate other chelating chemicals and hydrogen sulfide scavengers for control of iron sulfide precipitation at temperatures above 250 °F.
Diffusion Coefficients of Demulsifiers AP Measuring by Isotopic Labeled and Liquid Scintillation Counting Technique
Authors: Jiatai Bu , Wenhai Chen , Yabin Niu 
Published: December 2007

Abstract
This paper will firstly introduce the method of diffusion coefficient measuring in situ. Then the presentation is to be given that the diffusion coefficients of demulsifier AP between toluene and water are measured by isotopic labeled and liquid scintillation counting technique; The affection of NaCl on the diffusion behaves of demulsifier AP211 is also discussedin this paper
Novel Scale Removers Are Developed for Dissolving Alkaline Earth Deposits
Authors: Frenier Wayne W. 
Published: December 2007

Abstract
Scales are minerals that form on a surface due to the saturation of the local environment with an inorganic salt. The major categories of scales are: carbonates (Ca, Mg, Fe(II)), sulfates (Ca, Ba, Sr, Ra), oxides and hydroxides (Fe(II), Fe(III), Mg), sulfides (Fe(II) and Zn) and silicates (Ca, Mg, Al and Na).
The testing and categorizing of various classes of scale removal chemicals is described in this paper. The primary deposits studied were calcite, gypsum and barium sulfate. A variety of solvents, including organic acids and chelating agents were tested. Total capacity tests as well as kinetic tests were conducted to develop improved scale removal formulations.
One result has been the development of solvent formulations based on hydroxyaminocarboxylic acid (HACA) chelating agents. The tests demonstrated that HACAs are better overall complexers and solvents than aminocarboxylic acids or carboxylic acid type chelating agents in many scale dissolution formulations. A major benefit of HACAs are their high solubility in aqueous solutions from pH values &lt;1 to&gt; 12. Thus, an almost infinite number of custom formulations can be constructed. Some of the formulations have dissolution capacities that are equivalent to 7.5% HCl. One of the new materials, hydroxyethyliminodiacetic acid (HEIDA) is completely biodegradable and this contributes to the "greening" of oilfield chemicals.
Iron Sulfide Scale Deposit Formation and Prevention under Anaerobic Conditions Typically Found in the Oil Field
Authors: Przybylinski John L. 
Published: December 2007

Abstract
Iron sulfide deposition is a significant oilfield problem that has been ignored for the most part because of the perceived difficulty in preventing its formation. Usually iron sulfide is allowed to form and the resulting deposit problem remediated by either acid treatment or mechanical cleaning. Neither option is attractive in that acid cleaning is hazardous and mechanical cleaning is expensive.
Iron sulfide is not a single entity, but can exist in numerous forms. This paper discusses the various forms of iron sulfide. It compares the solubilities of iron and other sulfides with the solubilities of other mineral scales typically found in the oilfield and shows that it should be possible to inhibit the formation of ferrous sulfides using threshold inhibitors.
The perceived difficulty of preventing the formation of iron sulfide arises primarily from the very real problems involved in studying it in the laboratory under the anaerobic conditions typically found in the oilfield. These problems and solutions to some of them are discussed. The paper presents laboratory and limited field data showing how the deposition of ferrous sulfides may be reduced significantly.
Move to Environmentally Acceptable Products: How the OSPARCOM legislation affects the Introduction of New Products
Authors: Killaars Janine , Finley Pat 
Published: December 2007

Abstract
The Oslo-Paris Commission (OSPARCOM) has implemented strict guidelines for the use and discharge of chemicals used by oil and oil service companies in the North Sea. The ecotoxicity tests that must be performed according to OSPARCOM guidelines, as well as the country-specific prescreening and the soon-to-be-implemented Chemical Hazard and Risk Management (CHARM) model, have a major impact on the development of new products. In the commercial development phase of oilfield chemicals not only the performance, but also the environmental properties of the product must be taken into account.
This paper describes two examples of products that were successfully replaced with more environmentally acceptable alternatives. The improvement from an environmental point of view is outlined. The following parameters will be taken into account: Why is the product being replaced?Environmental properties (bioaccumulation, biodegradation, aquatic toxicity)Prescreening results in Norway, Denmark, and UKCHARM evaluation results
Comparisons of replacement products with the original product will be given, based on the above mentioned parameters. The replacement products that have been introduced are environmentally more acceptable. Due to the fact that regulations will become stricter, oil and oil service companies will have to put increasing effort into compliance with environmental legislation.
Simultaneous Matching of Production Data and Seismic Data for Reducing Uncertainty in Production Forecasts
Authors: Guérillot D. , Pianelo L. 
Published: December 2007

Abstract
Matching procedures are often used in reservoir production to improve geological models. In reservoir engineering, history matching leads to update petrophysical parameters in fluid flow simulators to fit the results of the calculations with observed data. In the same line, seismic parameters are inverted to allow the numerical recovery of seismic acquisitions. But these inversion processes are made separately and are poorly constrained.
The idea of this original work is to simultaneous match both the permeability and the acoustical impedance of the reservoir for an enhancement of the resulting geological model.
Comparison of the coupled matching with the two separated conventional ones realized on a 3D case demonstrates the practical efficiency of our method.
This work is an important step in a way of data integration. It allows to use simultaneously the available hard and soft data, as the knowledge of the depositional environment, seismic, and/or dynamic information.
Decision Analysis for Integrated Reservoir Management
Authors: Evans Robin 
Published: December 2007

Abstract
Decision analysis (DA) is presented as
A tool for carrying out a thorough and logical evaluation of alternative strategies, A means of systematically determining the best available reservoir management strategy with the objective of maximizing the net present value of the asset and the company.
Decision analysis is a framework for conducting integrated reservoir management. It is possible to integrate reservoir engineering, environmental regulations, environmental impact assessment, geochemistry, geological studies, process design, risk analysis, QC and financial appraisals with the aim of maximising the return on investment.
The value of decision analysis is not only in helping to structure information and thinking, but also in providing a vehicle for communication between different groups and technical disciplines. A complex decision problem is decomposed into separate components, often in the form of a decision tree, on which perceptions of options, uncertainties and values can be explicitly represented. Decision analysis is an ideal tool for decision making in an environment of risk and uncertainty.
The selection of a strategy for produced water handling and disposal is presented as an example of an application of decision analysis involving the integration of a variety of disciplines.