Influence of the concentrations of xanthan gum, hydroxypropyl starch and potassium chloride on the flow properties of drilling fluid formulations

Drilling operation of oil wells involves high costs and risks. With recent discoveries of deeper reservoirs and difficult to access, there was an increase in the number of horizontal wells drilled and far-reaching, and, thereat, new challenges with operational problems. Fluids, or muds, drilling are essential to the well drilling process, confirming the need to study and find physical, rheological, and filtration properties, appropriate to the complexities in each section and the drilling stage. Optimized formulation is the one that comprises a safe operation, mitigation of operational problems, environmental protection, low cost, and high productivity. Thus, this paper offers the study of the rheological properties, and determination of filtrate volume, of the aqueous base fluid formulations, developed with polymeric additives. A high performance formulation, presenting technical-economical feasibility for drilling operations, was achieved using 0.43% m/v of viscosifier (xanthan gun), 0.57% m/v of filtrate controller (hydroxypropyl starch) and 4.57% m/v of clay swelling inhibitor (KCl).La operación de perforación de pozos de petróleo implica altos costos y riesgos. Con los recientes descubrimientos de depósitos más profundos y de difícil acceso, hubo un aumento en el número de pozos horizontales perforados y de largo alcance y, por lo tanto, nuevos desafíos con problemas operacionales. Los fluidos o los lodos de perforación son esenciales para el proceso de perforación del pozo, confirmando la necesidad de estudiar y encontrar propiedades físicas, reológicas y de filtración, adecuadas a las complejidades de cada sección ya la fase de perforación. La formulación optimizada es aquella que comprende una operación segura, mitigación de problemas operacionales, protección ambiental, bajo costo y alta productividad. Así, este trabajo ofrece el estudio de las propiedades reológicas y de volumen de filtrado de las formulaciones de fluidos de base acuosa, desarrolladas con aditivos poliméricos. Una formulación de alto rendimiento, presentando viabilidad técnico-económica para operaciones de perforación, fue alcanzada utilizando 0,43% mv de viscosificante (goma xantana), 0,57% m / v de controlador de filtrado (hidroxipropilamido) y 4,57% m / v de inhibidor de la hinchazón de arcilla (KCl)

La influencia de los productos químicos en la precipitación de asfaltenos: una comparación entre las técnicas de microscopía de fuerza atómica y de infrarrojo cercano

Asphaltenes can cause serious problems to petroleum industry. Indication of asphaltenes stability can be obtained by precipitation induced by n-heptane, monitored by near-infrared (NIR). However, this technique does not provide information on the particles sizes. In this study, the precipitation onset of model systems (1wt% asphaltenes in toluene) was monitored by NIR, with and without adding additive. The particles sizes of the same systems were monitored by atomic force microscopy (AFM): Dispersions of asphaltenes in toluene, n-heptane and mixtures of these two solvents were analyzed by AFM. For the pure model system, the size of the asphaltenes aggregates clearly increased in function of rising n-heptane concentration in the solvent mixture, with this increase being much more pronounced for solubility parameter values below that corresponding to the precipitation onset. In the presence of additives, significantly smaller particles were obtained even when the precipitation onset showed only a slight shift

The influence of chemicals on asphaltenes precipitation: a comparison between atomic force microscopy and near infrared techniques

Los asfaltenos pueden causar serios problemas en la industria de petróleo. La evaluación de la estabilidad de los asfaltenos puede ser obtenida a través de la precipitación inducida por n-heptano, monitoreada por infrarrojo cercano (NIR). Sin embargo, esta técnica no provee información al respecto del tamaño de partículas. En este estudio, el onset de precipitación de sistemas modelo (asfaltenos en tolueno 1%p) fue monitoreado por NIR, con y sin la adición de aditivo. Los tamaños de partículas de los mismos sistemas fueron monitoreados por microscopía de fuerza atómica (AFM): dispersiones de asfaltenos en tolueno, n-heptano y mezclas de estos dos solventes fueron analizadas por AFM. Para el sistema modelo puro, el tamaño de los agregados de asfaltenos aumentó claramente en función del aumento de la concentración de n-heptano en la mezcla de solventes, siendo este aumento más marcado para valores de parámetros de solubilidad menor que el correspondiente al onset de precipitación. En la presencia de aditivos, partículas significativamente menores fueron obtenidas aun cuando el onset de precipitación mostró sólo un ligero cambio.Asphaltenes can cause serious problems to petroleum industry. Indication of asphaltenes stability can be obtained by precipitation induced by n-heptane, monitored by near-infrared (NIR). However, this technique does not provide information on the particles sizes. In this study, the precipitation onset of model systems (1wt% asphaltenes in toluene) was monitored by NIR, with and without adding additive. The particles sizes of the same systems were monitored by atomic force microscopy (AFM): Dispersions of asphaltenes in toluene, n-heptane and mixtures of these two solvents were analyzed by AFM. For the pure model system, the size of the asphaltenes aggregates clearly increased in function of rising n-heptane concentration in the solvent mixture, with this increase being much more pronounced for solubility parameter values below that corresponding to the precipitation onset. In the presence of additives, significantly smaller particles were obtained even when the precipitation onset showed only a slight shift

Estudo de soluções aquosas de copolímeros em bloco de poli(óxido de etileno)-poli(óxido de propileno) utilizando calorimetria exploratória diferencial (DSC) Study of poly(ethylene oxide-b-propylene oxide) block copolymers in aqueous solutions by differential scanning calorimetry

O comportamento de sistemas aquosos contendo copolímeros dibloco monofuncionais de poli(óxido de etileno)-poli(óxido de propileno), bloqueados em uma das extremidades da cadeia com segmento hidrocarbônico linear, foi avaliado através de calorimetria exploratória diferencial (DSC). Transições endotérmicas foram observadas no aquecimento das soluções dos copolímeros e as temperaturas iniciais destas transições estão de acordo com os pontos de turvação dos copolímeros estudados. Nas curvas de resfriamento, são observadas duas transições, e quanto mais rápido é resfriada a solução de copolímero, melhor é observada a transição que deve estar relacionada à formação das micelas. A influência da presença de um agente hidrotrópico também foi avaliada em todas as soluções de copolímeros por meio do aumento no ponto de turvação com o aumento da concentração do agente hidrotrópico, visto que os picos endotérmicos foram deslocados para temperaturas mais altas.The behavior of aqueous systems containing block copolymers of poly(ethylene oxide) (PEO) and poly(propylene oxide) (PPO), coupled to hydrocarbon groups, was evaluated by differential scanning calorimetry (DSC). Endothermic transitions in the copolymer solutions were observed under a linear heating rate and the initial temperatures of these transitions are in agreement with the cloud points of the copolymers studied. Two transitions were observed in the cooling curves; these transitions were better defined at faster cooling rates of the copolymer solutions which can be related to the micelles formation. The effect of the increasing concentration of the hydrotropic agent, sodium p-toluenesulfonate (NaPTS), in the copolymer solutions was observed by the increase in the cloud points given by the dislocation of the endothermic peaks to higher temperatures

Avaliação de aditivos poliméricos à base de éster fosfórico como modificadores da cristalização de parafina Evaluation of polymeric phosphoric ester-based additives as modifiers of paraffin crystallization

O desafio da produção de óleos parafínicos e óleos pesados tem sido destaque no cenário de inovações tecnológicas na indústria do petróleo. Este trabalho apresenta a obtenção de um novo aditivo químico de base polimérica, e sua avaliação como modificador da cristalização de parafinas de petróleo. O polímero foi obtido pela reação de éster fosfórico de cadeia longa e aluminato de sódio, de modo a gerar uma molécula de peso molecular relativamente alto e de características anfifílicas. Os estudos foram realizados utilizando um sistema-modelo de parafina de petróleo (P140) dissolvida em solvente parafínico. Ensaios reológicos, calorimétricos, cromatográficos e de microscopia óptica e eletrônica de varredura evidenciaram a ação do aditivo como modificador da cristalização de parafinas, sendo que a eficiência se mostrou dependente do peso molecular do polímero.The challenge of producing paraffinic and heavy oils plays an important role in the scenario of technological innovations in the petroleum industry. This work presents the synthesis of a new polymer-based chemical additive, and its evaluation as inhibitor of petroleum paraffin deposition. This polymer was obtained by reacting a long chain phosphoric ester with sodium aluminate, generating a molecule with relatively high molecular weight and amphiphilic character. The studies were carried out using a model-system of petroleum paraffin (P-140) dissolved in paraffin solvent. Rheological, calorimetric, chromatographic and optical and electron microscopy tests demonstrated that the additive acts as modifier of petroleum paraffin. The efficiency depended on the polymer molecular weight

Avaliação da interação macromolécula/íon Zn+2 em meio aquoso: poli(acrilamida-co-ácido acrílico) e taninos Estimation of the macromolecules/zinc ion interaction in the aqueous solution: poly(acrylamide-co-acrylic acid) and tannins

Este trabalho visa o estudo da interação entre polímeros sintéticos e produtos naturais à base de taninos com o íon zinco (Zn+2) em meio aquoso para sua utilização na remoção de metais em efluentes. Uma série de copolímeros poli(acrilamida-co-ácido acrílico) de diferentes composições e homopolímeros de acrilamida e de ácido acrílico foram preparados, assim como, taninos comerciais foram utilizados como recebidos e purificados por extração. Uma metodologia de avaliação da eficiência de interação da macromolécula com o íon Zn+2 foi desenvolvida baseada em curva padrão de intensidade de absorção na região do ultravioleta-visível (UV-VIS) em função da concentração do complexo formado, utilizando colorimetria. A capacidade de interação com o íon zinco foi ligeiramente maior para os polímeros sintéticos porém o produto natural tem a vantagem de apresentar um custo mais baixo.<br>The aim of this work was to evaluate the interaction between natural and synthetic macromolecules with the zinc ion (Zn+2) in aqueous solution. Polyacrylamide, poly(acrylic acid) and poly(acrylamide-co-acrylic acid) were prepared and natural products (tannins) were extracted and purified from commercial products. The methodology to evaluate the macromolecule/zinc ion interaction was based on colorimetry by using a standard curve. The interaction efficiency was slightly larger for the synthetic macromolecules when compared to the natural one. Nevertheless, the tanning has lower cost and its use could be recommended

Influência das condições reacionais nas características de copolímeros de metacrilato de metila e divinilbenzeno obtidos por polimerização em suspensão Influence from the reaction conditions on the characteristics of methyl methacrylate-divinylbenzene copolymers obtained by suspension polymerization

Foram sintetizados copolímeros esféricos e porosos à base de metacrilato de metila e divinilbenzeno através de polimerização em suspensão aquosa utilizando metil-etil-cetona (MEK) e ciclo-hexano (CH) como diluentes. Diferentes estruturas morfológicas foram obtidas através da modificação dos parâmetros reacionais tais como teor de divinilbenzeno e razão MEK/CH. Os copolímeros foram caracterizados por porosimetria de mercúrio, análise de área específica, densidade aparente e microscopia ótica. Foram obtidas estruturas macroporosas com os teores mais altos do DVB e do diluente não-solvatante (CH).Spherical and porous copolymers based on methyl methacrylate and divinylbenzene were synthesized by aqueous suspension polymerization using methyl-ethyl-ketone (MEK) and cyclohexane (CH) as diluents. Different morphological structures were obtained by modifying the reaction parameters, such as divinylbenzene content and MEK/CH ratio. The copolymers were characterized by several techniques: mercury porosimetry, specific superficial area analyzer, apparent density and optical microcopy. Macroporous structures were obtained when using high content of DVB and of nonsolvatant diluent (CH)

Degradation of non-vulcanized natural rubber - renewable resource for fine chemicals used in polymer synthesis

In the current scenario, there is growing interest in the products of degradation of rubber (natural and synthetic) for specific applications in different industry sectors, whose benefits in replacing conventionally used products are mainly related to sustainability. Since the degradation products of rubber can be used in different areas, several research groups may have the interest aroused by these products, but are not familiar with the aspects related to the chemical behavior of rubber. This review aims to bring together the key information in the published literature on the degradation of natural rubber, emphasizing metatheses reactions, oxidative damage and splitting of the double bond, in order to serve as a reference source for researchers from different fields interested in obtaining such kind of products. The structures and properties as well as additional chemical transformations resulting in oligomers of isoprene, functionalised oligomers and polymers based on both are also described