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Pau, France

Ghannam L.,Lebanese University | Billon L.,IPREM
Journal of Colloid and Interface Science | Year: 2012

This study describes the mechanism of adsorption of polystyrene chains PS " in situ" growth from micro-sized commercial silicate particles, i.e. Feldspar. The main aim is to derive adsorption isotherms from thermal gravimetric analysis (TGA) and size exclusion chromatography (SEC) data obtained during the direct polymerization of PS initiated by a pre-adsorbed radical initiator onto the inorganic surface. The adsorption isotherm plot indicates that the PS adsorption is in accord with the Langmuir Model. The amount of PS monolayer coverage increases with polymerization time, and it is highly dependent on the monomer diffusion to the surface during the hybrid inorganic/organic synthesis. Such behavior depends on the concentration gradient between monomer concentration in solution and that adsorbed by polymerization onto the micro-sized particles surface of Feldspar. © 2012 Elsevier Inc. Source

Rambeau O.,Total S.A. | Andreu N.,IPREM | Loriau M.,Total S.A. | Passade-Boupat N.,Total S.A.
Society of Petroleum Engineers - SPE EOR Conference at Oil and Gas West Asia, OGWA 2016 | Year: 2016

A side effect of EOR polymer flooding on topsides process chain is the generation of stable thin emulsion in viscous water phase. Both viscosity and severe emulsion impede the efficiency of water treatment technologies. The viscosity of the back produced polymer increases the time of clarification of oily water phase. The target of the water treatment specialist would be to collapse the viscosity of the produced water. The main concern is to decrease the viscosity of the produced water containing polymer back produced, acting on the degradation of the polymer without generating more severe oily emulsion. Shearing, a well known mode of degradation has been compared to other techniques such as chemical oxidation (bleach) and sonication. All the tests were performed with a high molecular weight polyacrylamide commonly used in EOR; at bench lab scale on synthetic viscosified produced water and on back produced water from field with cEOR flooding. Degradation efficiency was evaluated through viscosity measurements and polymer molecular weight analyses. This paper presents the results of the different investigations carried out to drop the viscosity of the produced water to an acceptable value for water treatment. Chemical oxidation using bleach has proved its efficiency on synthetic produced water. Different shearing conditions and different powers of sonication have also highlighted actions on the polymer and on the viscosity of the water phase. Even if all the tested degradations lead to a significant viscosity drop of the synthetic viscosified water, the improvements on water treatment were not equivalent. Analytical measurements of the molecular weight of the degraded polymer allowed initiating a scale of degradation efficiency. The efficiency, feasibility, difficulty, beneficial impact on water treatment and level of readiness of the technology have been estimated. An assessment of the different techniques for the polymer degradation in water treatment is presented at the end of this paper. The feasibility to decrease the viscosity of the back produced water would allow to simplify the water treatment process chain dedicated to polymer flooding case. Works continues on integrated water treatment process, including pre-degradation of the polymer back produced. Copyright 2016, Society of Petroleum Engineers. Source

Rodriguez L.,IPREM | Mejia A.,IPREM | Reynaud S.,IPREM | Lespes G.,IPREM | And 8 more authors.
Society of Petroleum Engineers - SPE EOR Conference at Oil and Gas West Asia, OGWA 2016 | Year: 2016

Chemical EOR polymers are in general anionic, synthetic, acrylamide based co-and ter-polymers. Those polymers provide viscosity to water based system thanks to their high molecular weight (Mw) and the repulsions between the ionic charges. Uncoiling and entanglements are the two mechanisms linked to Mw and ionic repulsion. When a polymer is injected, different mechanisms will act on its chemical structure by chemical, mechanical, thermal, free radical modifications. The understanding of the resulting rheological properties of the modified PAM is very important since it can change the control over the mobility ratio when it propagates downhole in the reservoir. Various lab experiments can be performed to predict those changes over time. In particular, the intrinsic viscosity is a convenient way of reaching the dimension of the macromolecule in a given solvent and at a given temperature but is time consuming. In this publication, a new and efficient capillary rheology technique is presented allowing measuring the bulk solution rheology and intrinsic viscosity of polymers in various brines even at high temperature (140° C) and at a controlled and low shear rate. It is thus possible to access to the rheological properties of dilute polymer solutions under conditions that, to our knowledge, cannot be performed by viscometers commercially available. The new technique involves a specific set up including a capillary and pressure transducers. It allows monitoring the effect of various chemical, mechanical, free radical and thermal modifications on the PAM structure after various ageing times. The performances of the technique were determined in terms of accuracy, and acquisition time. Various PAM compositions and different molar masses (104-106 g/mol) were used for calibration purposes. The technique was then applied to investigate the behavior of two industrial PAM (M>106g/mol) used in EOR: A sodium acrylamido-Tertiary-butyl sulfonate (ATBS) based PAM (SPAM), and a PAM terpolymer with ATBS, and N-vinylpyrrolidone (NVP) (PAM called SAV). Rheological properties and intrinsic viscosities were determined at low shear rates 8 to 800 s-1, at 25, 85 and 140°C, and for different salinities (20,000 to 240,000 TDS). In addition, the mechanical stability was evaluated by injection of a polymer solution in a capillary with a low internal diameter (125μm), and with a shear rate up to 1,500,000s-1. The results obtained using the new technique provide an efficient and reliable way of selecting the proper PAM chemistry for a given reservoir condition. Ultimately, it defines the salinity, temperature and shear rate domains where the PAM, SPAM or SAV are stable. The technique can be automated, is made of transportable devices, can be used in anaerobic conditions and provides a fast way of following changes in the rheological property of very high Mw industrial PAM over time. Copyright 2016, Society of Petroleum Engineers. Source

Parat C.,IPREM | Aguilar D.,University of Lleida | Authier L.,IPREM | Potin-Gautier M.,IPREM | And 3 more authors.
Electroanalysis | Year: 2011

AGNES (Absence of Gradients and Nernstian Equilibrium Stripping) has been implemented with screen-printed electrodes (SPE) for the determination of the free concentration of Zn2+, Cd2+ and Pb2+. For SPE, the stripped charge is a suitable response function which does not require the second stage of AGNES to be under diffusion limited conditions. This property can be used in the avoiding of the interference of Pb on [Cd2+] determination. The proportionality factor between stripped charge and concentration of amalgamated metal depends on the volume of mercury and opens the way to a future calibrationless strategy. Zn and Cd complexation with oxalate at various pH-values confirms the suitability of the developed methodology, which compares favourable with the standard one based on the Hanging Mercury Drop Electrode. © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim. Source

Aparaschivei R.,Al. I. Cuza University | Aparaschivei R.,Technical University Gheorghe Asachi | Sunel V.,Al. I. Cuza University | Popa M.,Technical University Gheorghe Asachi | Desbrieres J.,IPREM
International Journal of Polymeric Materials and Polymeric Biomaterials | Year: 2014

The results reported represent a continuation of the research on the synthesis of new 2-mercaptobenzoxazole derivatives with potential pharmacological activity and corresponding conjugates prepared by chemical immobilization through ester and amidic bonds onto poly(maleic anhydride-alt-vinyl acetate). New sulfonic compounds derived from 2-mercaptobenzoxazole were synthesized in order to obtain substances with a nucleophilic capacity. Their immobilization on copolymer support, based on poly(maleic anhydride-alt-vinyl acetate) through ester or amidic bonds led to polymer-biologically active principle conjugates with controlled release capacity. Release of the compound immobilized by ester bonds was found to take place in the first 5-6 h. The 2-mercaptobenzoxazole derivatives and the conjugates were characterized using elemental and spectral analysis (FT-IR, 1H-NMR). Toxicological and antimicrobial tests were performed, recommending some of these therapeutics as candidates for pharmacological applications. © 2014 Taylor and Francis Group, LLC. Source

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