Underground injection of acid gas has been studied for several decades for oil field applications, such as enhanced oil recovery (EOR), but is now being studied as a solution to climate change. This research aims to simulate underground conditions at injection sites, such as the pilot scale injection site located near the site of a coal fired power facility in the Black Warrior Basin of Alabama. This proposed carbon capture and sequestration (CCS) location would involve injection of liquid CO2 into a carbonaceous saline aquifer. The objective of this study was to investigate carbonate surface treatments that alter the kinetics and mechanism of mineral dissolution resulting from the injection of an acid gas (CO2) into a geologic formation. A variety of mineral coatings were tested in an attempt to preserve mineral integrity under acidic conditions. Surface active chemicals were first tested, including scale inhibitors, followed by a novel acid induced surface treatment that precipitates an inorganic layer on the calcite to preserve the acid soluble mineral. These experiments are the first to investigate the use of scale inhibitors for mineral preservation, although were found ultimately to have little impact on dissolution kinetics. However, anions of moderate to strong acids induced surface coatings that were determined to effectively inhibit dissolution. Additionally, a novel, high pressure flow-through experimental apparatus was developed to simulate pressure and temperature conditions relevant to injection sites. Similar mineralogical studies in the literature have used pressurized, unstirred, batch systems to simulate mineral interactions. Solids with an acid induced surface coating were tested in the high pressure column and no calcium was found to leave the column.

Underground injection of acid gas has been studied for several decades for oil field applications, such as enhanced oil recovery (EOR), but is now being studied as a solution to climate change. This research aims to simulate underground conditions at injection sites, such as the pilot scale injection site located near the site of a coal fired power facility in the Black Warrior Basin of Alabama. This proposed carbon capture and sequestration (CCS) location would involve injection of liquid CO2 into a carbonaceous saline aquifer. The objective of this study was to investigate carbonate surface treatments that alter the kinetics and mechanism of mineral dissolution resulting from the injection of an acid gas (CO2) into a geologic formation. A variety of mineral coatings were tested in an attempt to preserve mineral integrity under acidic conditions. Surface active chemicals were first tested, including scale inhibitors, followed by a novel acid induced surface treatment that precipitates an inorganic layer on the calcite to preserve the acid soluble mineral. These experiments are the first to investigate the use of scale inhibitors for mineral preservation, although were found ultimately to have little impact on dissolution kinetics. However, anions of moderate to strong acids induced surface coatings that were determined to effectively inhibit dissolution. Additionally, a novel, high pressure flow-through experimental apparatus was developed to simulate pressure and temperature conditions relevant to injection sites. Similar mineralogical studies in the literature have used pressurized, unstirred, batch systems to simulate mineral interactions. Solids with an acid induced surface coating were tested in the high pressure column and no calcium was found to leave the column.

A injeÃÃo de Ãgua do mar em poÃos de petrÃleo para recuperaÃÃo do Ãleo à o mecanismo mais empregado nas unidades de produÃÃo. Entretanto esse mÃtodo provoca a formaÃÃo de incrustaÃÃo, devido à incompatibilidade salina com a Ãgua de formaÃÃo do poÃo. A deposiÃÃo de sais reduz a produtividade dos poÃos e causa entupimento das linhas de produÃÃo, aumentando, assim, os custos com manutenÃÃes corretivas. A fim de reduzir esses danos utiliza-se a tÃcnica squeeze de injeÃÃo de inibidor de incrustaÃÃo, na qual o anti-incrustante à adsorvido na superfÃcie da formaÃÃo rochosa evitando a formaÃÃo dos cristais. Com isso, a fim de compreender o mecanismo de retenÃÃo do inibidor na rocha realizou-se estudos de adsorÃÃo em leito fixo utilizando uma rocha do tipo arenÃtica desagregada, com diÃmetro mÃdio de partÃcula igual 605 Âm e um inibidor de incrustaÃÃo comercial. Foram levantados as isotermas de adsorÃÃo/dessorÃÃo de N2 e ensaios de DRX para caracterizar a rocha bem como ensaios de FTIR para determinaÃÃo de uma possÃvel composiÃÃo do inibidor. Os ensaios de adsorÃÃo foram realizados nas temperaturas de 30, 50 e 80ÂC, a uma vazÃo de 0,1 mL/min e variou-se a concentraÃÃo de alimentaÃÃo do inibidor de 1 a 10 mg/mL. Utilizou-se a tÃcnica de Espectroscopia de EmissÃo Ãtica com Plasma Indutivamente Acoplado (ICP-OES) para determinar a concentraÃÃo de inibidor no efluente e construir as curvas de breakthrough e as isotermas. AlÃm disso, foi realizado simulaÃÃo do sistema para estimativa de parÃmetros de transferÃncia de massa. O leito estudado apresentou porosidade de 57% e dispersÃo axial de 0,178 cm2/min. A rocha à constituÃda por Ãxido de silÃcio e as partÃculas apresentaram porosidade de 0,68% e 2,66 g/cm3 de massa especÃfica. O inibidor apresentou fÃsforo na sua composiÃÃo sendo esse monitorado pelo ICP para determinaÃÃo da concentraÃÃo de inibidor na saÃda do leito. Com as isotermas de adsorÃÃo, observou-se que a capacidade mÃxima adsorvida variou de 3 a 28 mg/g. O modelo matemÃtico proposto para simular o sistema trabalhado se ajustou bem aos dados experimentais e foi possÃvel estimar alguns parÃmetros de transferÃncia de massa como coeficiente global de transferÃncia de massa e a tortuosidade mÃdias das partÃculas adsorventes. Observou-se pelos dados obtidos que o inibidor à adsorvido na superfÃcie do sÃlido, pois a partÃcula apresentou baixa porosidade e tortuosidade. / Seawater injection in oilfield is technic used to recover petroleum in production units. However, this method induces scale formation because formations water is incompatible with injection water. The salt deposition reduces oilfield production and induces blocking of production lines, increasing costs with corrective maintenance. To reduce theses damages was used the squeeze technic, where a scale inhibitor is adsorbed in rock surface to avoid crystals formation. With that, to understand the mechanism of inhibitor retention in the rock, was realized studies in bed fixed with particles of sandstone rock, with 605 Âm medium diameter, and scale inhibitor commercial. Isotherms of N2 adsorption/desorption and XDR analyses were realized to characterization of rock and FTIR analyses to determine of composition inhibitor. Tests adsorption were realize at 303, 323 and 353 K, with flow of 0.1 mL/min and at inhibitor concentration 1 to 10 mg/mL. Optical Emission Spectroscopy Inductively Coupled Plasma (ICP-OES) was used to determinate inhibitor concentration in the effluent and build isotherms and breakthrough curves. Furthermore, simulations of the system were realized to estimate mass transfer parameters. The bed showed of 57% porosity and axial dispersion of 0.178 cm2/min. The rock is constituted to silicon oxide and particles showed of 0.68% porosity and density of 2.66 g/cm3. The inhibitor has phosphorus in its composition and this was monitored by ICP to determine the inhibitor concentration at the bed outlet. With adsorption isotherms observed maximum capacity adsorbed was 3 to 28 mg/g. The mathematical model proposed to simulated this system had a good adjusted and was possible estimated some parameters of mass transfer as global mass transfer coefficient of mass transfer and tortuosity of adsorbents. It was observed from the data obtained that the inhibitor is adsorbed on the solid surface, because the particle had low porosity and tortuosity.

Made available in DSpace on 2014-12-17T15:42:31Z (GMT). No. of bitstreams: 1 BrunaVL_TESE.pdf: 4965695 bytes, checksum: f511eb063b5cd567f364bc0ec9385727 (MD5) Previous issue date: 2014-05-28 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior / Sustainable development is a major challenge in the oil industry and has aroused growing interest in research to obtain materials from renewable sources. Carboxymethylcellulose (CMC) is a polysaccharide derived from cellulose and becomes attractive because it is water-soluble, renewable, biodegradable and inexpensive, as well as may be chemically modified to gain new properties. Among the derivatives of carboxymethylcellulose, systems have been developed to induce stimuli-responsive properties and extend the applicability of multiple-responsive materials. Although these new materials have been the subject of study, understanding of their physicochemical properties, such as viscosity, solubility and particle size as a function of pH and temperature, is still very limited. This study describes systems of physical blends and copolymers based on carboxymethylcellulose and poly (N-isopropylacrylamide) (PNIPAM), with different feed percentage compositions of the reaction (25CMC, 50CMC e 75CMC), in aqueous solution. The chemical structure of the polymers was investigated by infrared and CHN elementary analysis. The physical blends were analyzed by rheology and the copolymers by UV-visible spectroscopy, small-angle X-ray scattering (SAXS), dynamic light scattering (DLS) and zeta potential. CMC and copolymer were assessed as scale inhibitors of calcium carbonate (CaCO3) using dynamic tube blocking tests and chemical compatibility tests, as well as scanning electron microscopy (SEM). Thermothickening behavior was observed for the 50 % CMC_50 % PNIPAM and 25 % CMC_75 % PNIPAM physical blends in aqueous solution at concentrations of 6 and 2 g/L, respectively, depending on polymer concentration and composition. For the copolymers, the increase in temperature and amount of PNIPAM favored polymer-polymer interactions through hydrophobic groups, resulting in increased turbidity of polymer solutions. Particle size decreased with the rise in copolymer PNIPAM content as a function of pH (3-12), at 25 ?C. Larger amounts of CMC result in a stronger effect of pH on particle size, indicating pH-responsive behavior. Thus, 25CMC was not affected by the change in pH, exhibiting similar behavior to PNIPAM. In addition, the presence of acidic or basic additives influenced particle size, which was smaller in the presence of the additives than in distilled water. The results of zeta potential also showed greater variation for polymers in distilled water than in the presence of acids and bases. The lower critical solution temperature (LCST) of PNIPAM determined by DLS corroborated the value obtained by UV-visible spectroscopy. SAXS data for PNIPAM and 50CMC indicated phase transition when the temperature increased from 32 to 34 ?C. A reduction in or absence of electrostatic properties was observed as a function of increased PNIPAM in copolymer composition. Assessment of samples as scale inhibitors showed that CMC performed better than the copolymers. This was attributed to the higher charge density present in CMC. The SEM micrographs confirmed morphological changes in the CaCO3 crystals, demonstrating the scale inhibiting potential of these polymers / O desenvolvimento sustent?vel ? um dos principais desafios da ind?stria do petr?leo, que tem despertado crescente interesse por pesquisas para obten??o de novos materiais provenientes de fontes renov?veis. A carboximetilcelulose (CMC) ? um polissacar?deo derivado da celulose, que se destaca por ser sol?vel em ?gua, renov?vel, biodegrad?vel, de baixo custo e por apresentar possibilidades de modifica??es em sua estrutura qu?mica. Dentre os derivados de carboximetilcelulose, alguns sistemas t?m sido desenvolvidos para induzir propriedades est?mulos-responsivos e ampliar a aplicabilidade desses materiais multirresponsivos. Embora esses novos materiais sejam atualmente objeto de estudo, a compreens?o de suas propriedades f?sico-qu?micas, tais como viscosidade, solubilidade e tamanho de part?culas em fun??o do pH e temperatura ainda ? muito limitada. Esta tese descreve sistemas de misturas f?sicas e copol?meros ? base de carboximetilcelulose e poli (Nisopropilacrilamida) (PNIPAM) com diferentes composi??es percentuais de alimenta??o reacional (25CMC, 50CMC e 75CMC), em solu??o aquosa. A estrutura qu?mica dos pol?meros foi investigada por infravermelho e an?lise elementar CHN. As misturas f?sicas foram analisadas por reologia e os copol?meros foram analisados por UV-vis?vel, espalhamento de raios-X a baixos ?ngulos (SAXS), espalhamento de luz din?mico (DLS) e potencial zeta. CMC e copol?mero foram avaliados como inibidores de incrusta??o de carbonato de c?lcio (CaCO3) usando os testes de compatibilidade qu?mica e precipita??o din?mica em capilar, assim como a microscopia eletr?nica de varredura (MEV). As misturas f?sicas 50% CMC_50% PNIPAM e 25% CMC_75% PNIPAM em solu??o aquosa, nas concentra??es de 6 e 2 g/L, respectivamente, apresentaram comportamento termoviscosificante dependente da concentra??o de pol?mero e da composi??o. Para os copol?meros, o aumento da quantidade de PNIPAM e da temperatura favoreceu as intera??es pol?mero-pol?mero atrav?s dos grupos hidrof?bicos, resultando no aumento da turbidez das solu??es polim?ricas. O tamanho das part?culas diminuiu com o aumento do teor de PNIPAM na composi??o dos copol?meros em fun??o do pH (3-12), a 25 ?C. Maiores quantidades de CMC resultaram em um efeito mais forte do pH nos tamanhos das part?culas, exibindo um comportamento pH-responsivo. Assim, 25CMC n?o foi afetada pela mudan?a de pH, apresentando comportamento similar a PNIPAM. Al?m disso, a presen?a de aditivos de car?ter ?cido ou b?sico influenciou no tamanho das part?culas, que foram menores na presen?a desses aditivos do que em ?gua destilada. Os resultados de potencial zeta tamb?m sofreram maior varia??o para os pol?meros em ?gua destilada do que na presen?a de ?cidos e bases. A temperatura consoluta inferior (LCST) da PNIPAM determinada por DLS foi concordante com o valor obtido por UV-visible. Os dados de SAXS mostraram para PNIPAM e 50CMC uma transi??o de fase quando a temperatura aumentou de 32 para 34 ?C. Um aumento do car?ter polieletrol?tico foi observado em fun??o do aumento da CMC na composi??o dos copol?meros. A avalia??o das amostras como inibidores de incrusta??o mostrou que a CMC apresenta um melhor desempenho do que o copol?mero. Isto foi atribu?do a maior densidade de cargas presente na CMC. As micrografias do MEV confirmaram mudan?as morfol?gicas dos cristais de CaCO3, indicando o potencial desses pol?meros para inibi??o de incrusta??o