Marina Seixas Pereira

Determination of the Chemical and Mineralogical Composition of Drilled Cuttings at Different Points throughout the Solids Control Process

In this work, we use x-ray fluorescence and x-ray diffraction methods to investigate the chemical and mineralogical composition of drilled cuttings at different points throughout the solids control process. Cuttings coated or contaminated with drilling fluid are the result of drilling. Over the past twenty years, studies have been conducted to assess the effects that these contaminated cuttings have on the environment, in both offshore and onshore scenarios. A more restrictive environmental legislation and the need to reduce drilling costs (exploration and production) has led to the optimization of solid-liquid separation. Knowledge of the chemical and mineralogical composition of drilled cuttings will assist in finding a dispersant and in determining an appropriate procedure for carrying out particle size analysis of these solids.

Kinetics of microwave heating and drying of drilling fluids and drill cuttings

ABSTRACT Drill cutting decontamination by microwave drying has been studied over the past few years and has proved to be a promising technology. This study aimed to investigate fundamental aspects of kinetics of heating and drying of drilling fluids and drill cuttings by microwaves. The microwave heating curve of cuttings free of fluid, drilling fluids, and pure organic compounds usually used in the formulation of these fluids was evaluated to understand the behavior of each component in microwave cutting decontamination. Furthermore, commercial software was used to describe the heating kinetics of the drilling fluids used in this study. The drying kinetics of cuttings contaminated with these drilling fluids was also studied at three temperatures of control. Some classic models of conventional drying of solids were used to describe the removal kinetics of the liquid components present in contaminated cuttings (water and organic compounds). Important aspects related to the interaction of these components in the drying operation and solid heating, water evaporation, and the drag of organic compounds were investigated. Both drilling fluids showed a very similar kinetic heating. Pure organic bases did not show a significant heating. For the same drying time, the removal of paraffin is more intense than the olefin. In respect to organic component removal from cuttings contaminated with both fluids, the kinetic drying curves are similar. The Page model was the one that best describes the drying operation of drill cuttings contaminated with both drilling fluids. The microwave drying model (MDM) model is proposed in this work as a simple modification in the Henderson–Pabis model: the addition of a third parameter. The incorporation of this parameter enabled a better fit of the experimental data. Computational simulations show an electric field with symmetrical patterns for the two BR-MUL fluids analyzed.

Physical Properties of Cuttings, Drilling Fluid and Organic Phase Recovered in the Drying Operation in Oil and Gas Well Drilling

Oil companies have increasingly invested in alternative technologies for cuttings treatment. The research for new operations or equipments leads to investigate the properties and characteristics of drilled cuttings and drilling fluids. This work presents the physical characterization of cuttings, drilling fluid and organic phase recoved after cuttings drying. It was carried out analysis of rheology for the drilling fluid and particle size and shape for the cuttings. Considering the microwave drying technology, which has been investigated for cuttings treatment, it was also determined the dielectric properties for the drilling fluid. The quality of the organic phase recovered in the microwave cuttings drying was also analysed.

Influence of Rock Chemical Composition in Microwave Heating and Decontamination of Drill Cuttings

Drill cuttings generated by oil and gas drilling process are incorporated into the drilling fluid to ensure an efficient drilling and solids removal. The drilling rigs have a separation system accountable for separating drill cuttings and drilling fluids. Microwave drying is a new technology of separation that has been studied as an alternative to the currently drill cuttings dryer used. The results obtained in preliminary studies showed that this microwave drying is sensitive to different oxides presents into the rock. Thus, this study aimed to describe the microwave heating kinetics of some rocks in order to verify the interaction of oxides with electromagnetic waves. For this, the oxide contents of the rocks were determined by X-ray Fluorescence and different rocks were heated in a microwave heating unit. The results showed that the relationship between the temperature and heating time is exponential and depends on the rock oxide contents. It was found that the iron oxides may be unstable at microwave and rocks with high levels of magnesium oxides and sulfates tend to be good absorbers of microwave. Rocks containing high levels of calcium, silicon, titanium, barium and chloride (NaCl) are not good absorbers of microwave. It was also noted that faster solid heating, lesser the efficiency of microwave drying.

Fundamentals of Microwave Heating and Drying of Drilled Cuttings

Drilled cuttings contaminated by non aqueous drilling fluids are the major waste from oil well drilling activities. More restrictive environmental legislation has led to the search for alternative technologies to promote cuttings decontamination according to the law. The mixture of cuttings and fluid returning from the well goes through a set of separation equipments, called solids control systems, in order to recover the drilling fluid for reuse. The cuttings from the solids control system must be decontaminated before they can be discharged into the sea. Microwave heating has been studied over the past few years as an alternative to promote the decontamination of this waste and has been shown to be a promising technology. This work aimed to investigate fundamental aspects of microwave heating and drying of drilled cuttings. The heating curve of two different drilling fluids commonly employed in well-drilling operations was obtained. The kinetics of drying of cuttings contaminated with these drilling fluids was also investigated. It was evaluated the behavior of organic phase and water removal in the microwave drying process.

Doença de Hodgkin: Massa da parede torácica anterior como forma de apresentação clínica

RESUMO Os autores descrevem um caso de doenca de Hodgkin, do subtipo esclerose nodular, numa mulher de 24 anos de idade. A forma de apresentacao clinica, pouco habitual, e constituida por uma massa na regao esternal e parede anterior do hemitorax esquerdo, a qual adquire grande volume ao fim de 2 anos e meio de evolucao natural da doenca. Esta e tratada com quimioterapia (MOPP) e radioterapia adjuvante, sofrendo uma reeressao total das suas manifestacoes clinicas. REV PORT PNEUMOL 1999; V (3): 349-355