Book

Polímeros en Contexto. Experiencias teórico-prácticas

August 2008

Authors:

Flavia C Zacconi

Pontifical Catholic University of Chile

Sandra A. Hernández

Universidad Nacional del Sur

ResearchGate has not been able to resolve any citations for this publication.

ResearchGate has not been able to resolve any references for this publication.

Article

Investigation of the true area of contact of polymers

December 1963 · Polymer Science U S S R

V.V. Lavrent'ev

Conference Paper

The Effects of Polymer Molecular Weight on the Elastic Instabilities In Microchannels

November 2008

We investigate the effects of polymer molecular weight (MW) on the flow of flexible polymeric solutions in an extensional flow produced in a microchannel. The relatively small length scale and high deformation rates lead to significant stretching of the flexible polymer molecules near the hyperbolic point. For high molecular weights (MW~10^6 to 10^7), the stretching produces two flow ... [Show full abstract] instabilities, one in which the velocity field becomes strongly asymmetric, and a second in which it fluctuates in time. The frequency and amplitude of the velocity oscillations depends both on the Deborah number and on polymer molecular weight. These instabilities do not occur for semi-rigid polymer solutions or Newtonian fluids.

Article

Development and Application of a Streamline Micellar/Polymer Simulator

October 1981

A large-scale, two-dimensional, muticomponent, multiphase, compositional simulator for micellar/polymer flooding has been developed and applied. It can be used to calculate the areal sweep with any well pattern and any irregular reservoir boundary. This model involves both streamline and finite-difference techniques. Time invarient streamlines without transverse dispersion are assumed. The change ... [Show full abstract] in the flow rates into each streamline is accounted for as a function of mobility ratio. Computation results show that a line drive pattern produces a greater tertiary oil recovery than a 5-spot under the same pressure drop. However, the injection time of the line drive is two-to-three times larger. On the other hand, the oil recoveries of a 5-spot and a 9-spot are very close, but the 9-spot requires a longer project life. The fractional oil recovery for a 5-spot is found to decrease as a function of increasing well spacing. It is also observed that the orientation of an anisotropic reservoir with a 5-spot pattern plays a very important role in the micellar/polymer process. The injection time for a 5-spot may be reduced by a factor of one-half to one-third if the polymer solution is shear thinning. The proper control of the production rate of a single or isolated 5-spot pattern can greatly increase tertiary oil recovery. In order to demonstrate that this model is capable of handling much larger field problems, a large-scale simulation of the north lease of the El Dorado micellar/polymer pilot test was made. The simulated final oil recovery and the production histories of each producer are illustrated.

Article

Diffusivity of Rescaled Random Polymer in Random Environment in dimensions 1 and 2

January 2012

Zi Sheng Feng

We show random polymer is diffusive in dimensions 1 and 2 in probability in an intermediate scaling regime. The scale is

\beta= o(N^{-1/4})

in d=1 and

\beta=o((\log N)^{-1/2})

in d=2 as

N\rightarrow \infty

Article

The kinetics of the epoxy amine cure reaction from a solvation perspective

July 2004 · Journal of Polymer Science Part A Polymer Chemistry

J. D. R. Talbot

This article investigates the role of solvation effects in the autocatalysis reaction of the epoxy–amine cure reaction. A single-phase three component model was developed encompassing a two-component reaction mix and a single polymeric product. The reaction was modelled as an SN2 reaction. Association of the nucleophile with each component in the reaction was defined via a binding constant. © ... [Show full abstract] 2004 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 42: 3579–3586, 2004

Article

Nuclear magnetic relaxation without spin diffusion in polymers at interfaces

August 1999 · Physical review A, Atomic, molecular, and optical physics

We consider theoretically the possibility of solid state NMR experiments with frozen linear polymer chains at interfaces. Three different cases are studied, namely, when the macromolecules are grafted on the surface, when they are adsorbed, and when they are very strongly adsorbed from a melt that is subsequently washed by a good solvent. The latter case is somewhat intermediate between the two ... [Show full abstract] former ones. For each case, we consider the relaxation when paramagnetic centers are located on the surface. We show that the shape of the relaxation curves depends critically on the monomer concentration profile, and exhibits characteristic power-law variations.

Article

Development and Application of Selective Polymer Injection to Control Water Production

August 1997

This paper presents the development and application of a process that is characterized by the injection of a rock adsorbing cationic polymer of selective behavior with regard to the flow of reservoir fluids. The polymer adsorbed to the rock surface forms a hydrophilic film that swells in the presence of water, and strongly reduces the water relative permeability. In the presence of oil, the film ... [Show full abstract] maintains its original thickness, only slightly reducing the oil permeability. Concurrently it was developed a simple and precise method for the diagnosis and selection of wells, mainly baed in the graphic analysis of the production data. The process has been tested in 17 oil wells of Fazenda Pocinho field, with water salinity around 3,000 ppm and temperatures up to 50 C. Water cuts between 70 and 90% decreased 10 to 20 percentile points in most of the treated wells. Furthermore, most of them also showed oil production increase. From an economic point of view, the selective polymer injection process has proven to be cost effective with both low chemical and operational costs. Introduction Water production in association with crude oil has been one of the major difficulties for the petroleum companies around the world. The breakthrough of either formation or injection water, results in accelerated oil production decline, increasing operational costs of pumping, treatment and disposal of large volumes of water. Several techniques are available to reduce water production, or to prevent its early breakthrough, and the choice of the adequate technique for each case, at first, depends on the source of the produced water. The reservoir and well analysis, therefore, must accurately define its origin. Water coning and injection water channeling frequently cause high water/oil ratios, and the use of flow barriers is frequently successful. These barriers can be either of the plugging or permeability reducing type, characterizing the blocking and selective systems, respectively. The plugging type barriers, which block simultaneously gas, water and oil flow, can be formed by cement, resins, solid particles suspensions, silicates, paraffin or water soluble polymers crosslinked "in situ" in the reservoir. On the other hand, selective systems mainly block the water flow, causing little or no restrictions at all to hydrocarbon flow. These selective barriers are generally formed by water soluble copolymers, that adsorb to the rock surface, forming a hydrophilic film that reduces the water mobility. The design of selective polymer systems depends on the rock mineralogy and permeability, reservoir temperature and formation water salinity. The rock type. sandstone or limestone, defines the polymer ionic character. The predominantly negatively charged adsorbing sites at the surf of sandstones calls for the cationic type of polyacrilamides. Conversely, limestones are flavored by the anionic of polymers to enhance the adsorbing capacity and thus the formation of the hydrophilic film responsible for the permeability reduction to water. Concerning the reservoir temperature and water salinity, polymer tolerance can be improved by adding products as AMPS (2-acrylamide-2-methylpropanesulfonic acid) and/or vinylpyrrolidone to the molecular structure of the base polymer. The salinity, however, can inhibit the hydrophilic film swelling and so impair the water phase permeability reduction effect. With respect to the rock permeability, the higher the rock permeability, the higher the hydrodynamic volume required for the polymer in the case of monolayer adsorption. It is also possible to improve the film thickness by adding successive alternate layers of anionic and cationic polymers. In the same way, it is possible to inject successive layers of selective polymer and crosslinking agents (e.g. trivalent metallic ions) to obtain a similar effect.

Article

Analysis of Volatile Constituents in Commercial Polymers by Direct Thermal Desorption and Gas Chroma...

October 1978 · Journal of Polymer Science Polymer Chemistry Edition

Article

Polymer Flood Modeling Using Streamlines-Part 1

September 2008

The successful design of a polymer flood relies on the ability to properly model the distribution of polymer concentration in the reservoir while accounting for effects on fluid properties such as water viscosity increases as a function of in-situ polymer concentration and loss of polymer due to adsorption. Despite advances in numerical techniques and computer hardware, the numerical modeling of ... [Show full abstract] polymer floods using Eulerian-based approaches such as finite differences remains a challenge: coarse grids tend to excessively smear concentration fronts masking the true benefit of polymers, yet introducing finer grids inevitably leads to excessive run times that make using modern reservoir engineering workflows unrealistic. This problem was already outlined in 1978 by Lake et al.. We revisit the same problem 30 years later in the context of modern streamline simulation techniques. In this work, we present the extension of modern streamline simulation to field-scale polymer flooding, which represents a step-change from the hybrid, 2D steady-state models used in the 1970's. We apply the well-established numerical modeling of polymer flooding to captured the displacement efficiency in 1D, and couple it with a three-dimensional (3D) streamline simulator to efficiently capture the inter-pattern sweep efficiency caused by well rate imbalances, reservoir architecture, and reservoir heterogeneity. Because modern 3D streamline simulators account for changing well rates, non-uniform initial conditions, and gravity, adding polymer functionality means that real-field polymer floods can be modeled with sufficient confidence to be useful and with the necessary speed to be used for modern reservoir engineering workflows that center on assessing uncertainty and risk associated with design parameters. In this paper we proceed to outline the basic architecture of a streamline simulator with a polymer option. We discuss streamline-specific issues, such as the data that must be exchanged between the Lagrangian streamline grid and the underlying Eulerian grid to allow streamlines to be updated as production/injection conditions change. We discuss advantages and disadvantages of the formulation and present numerical experiments in 1D, 2D, and 3D to illustrate our results. Modern Streamline Simulation In 1981 (originally presented in 1978), Lake et al. introduced a hybrid streamline approach to model large-scale chemical floods. The motivation for their approach was that finite-difference simulators with detailed physical descriptions could not be used for large-scale simulations, while streamtube-models that could account for large-scale simulations were "seriously" deficient in displacement physics. To solve this dilemma, they proposed to solve detailed cross-sectional simulations using finite differences and then map these pseudo-solutions along areal streamlines as a way to predict field performance of a chemical flood. Surprisingly, 30 years later this motivation still holds and the dilemma remains. Today's modern reservoir engineering workflows require many forward simulations, and the computational load using finite-differences to accommodate such workflows, particularly under the use of advanced displacement physics and geostatistics-driven reservoir models is simply too high for field performance predictions and management. While the compute-power has increased many hundredfold since 1981, so have model complexities. Finding an efficient and sufficiently accurate modeling technique for chemical flooding remains an important target, particularly under the current economic conditions of ever increasing oil prices (near $140/bbl at the time of writing of this article), which have sparked renewed interest in surfactant/polymer flooding.

Article

A Review of Polymer Conformance Treatment: A Successful Guideline for Water Control in Mature Fields

November 2011 · Energy Sources, Part A: Recovery, Utilization and Environmental Effects

Waterflooding has been practiced for several decades as a means of secondary recovery. This process is successful if there is uniform resistance to the injected water. However, due to its nature of heterogeneity, the injected water flows to the less resistant path, resulting in poor sweep efficiency. As one of many candidates to overcome this problem, polymer systems mixing with several types of ... [Show full abstract] chemical agents have been researched and applied for several years. In this article, the authors reviewed and summarized the Relative Permeability Modification/Disproportionate Permeability Reduction and water shutoff treatments.

Article

Polybutadiene block microstructure effect upon the star-type styrene-butadiene block copolymers ther...

January 2000 · Materiale Plastice

This paper presents the effect of polybutadiene microstructure on the star styrene-butadiene block-copolymers properties. The rising of 1,2 polybutadiene content improves mainly the polymers thermooxidation stability.

Conference Paper

Success and Prospects in Advanced Materials and Polymers

November 2008

Jocelyn E. Scott