Uso de polímeros hidrolisáveis em sistemas controladores de fluxo em poços de petróleo

Abstract

In this Thesis, the feasibility of modification of flux profile in inflow control systems installed in oil wells was investigated by introducing three polymers in specific stages of the process. Two hydrolysable polymers: poly (methylene oxide) (POM) and poly (glycolic acid) (PGA) and also polystyrene (PS), because of its solubility in aromatic media, were chosen, taking into account their mechanical and chemical properties. The materials were characterized by infrared spectrometry (FTIR), carbon-13 nuclear magnetic resonance (13C-NMR), differential scanning calorimetry (DSC), thermal gravimetric analysis (TGA), scanning electron microscopy (SEM), optical microscopy (OM), ion chromatography (IEC), high pressure liquid chromatography (HPLC), gel permeation chromatography (GPC), diffraction wide angle X-ray (WXRD) and computerized microtomography (Micro CT). Disk-shaped samples, previously prepared, were subjected to chemical products commonly employed in formations treatment, by using specific equipment (SIFAM). The disks were confined separately in metallic cylindrical cells, at static conditions, with substances normally used in the treatment of formations bearing hydrocarbons (aqueous solutions of HCl 15% m/m, acetic acid 10% m/m, formic acid 10% m/m, sodium chloride 23% m/m, potassium diethylene-triamine-penta-acetate salt 10%, dimethyl benzene and oil), at conditions found in oil fields in Campos Basin, Rio de Janeiro, Brazil (25, 50 and 75°C and pressure of 41.4 MPa). The exposure to saline solution took place in periods of 1, 5, 10, 15, 20 and 25 days, the exposure to acid for 1, 4, 8, 16 days and, to other products, for 24 h. After each of the defined periods, the samples, and their aqueous solutions were analyzed by 13C-NMR, DSC, TGA, SEM, OM, WARXD, and Micro CT, so as to evaluate the mass loss and other effects to chemical exposure of the investigated polymers, besides determining the reaction rate for the hydrolysis of POM and PGA in aqueous environment. Additionally, tests were performed to evaluate the pressure resistance of the disk-shaped samples. The results showed that the use of POM, PGA and PS in inflow control devices is feasible