Monday, May 4, 2009
9-45
Characterization of α-amylases for the removal filter cake on petroleum wall
Nattascha Kyaw1, Rafael F. Mesquita1, Etel Kameda1, Marta A. P. Langone2, and Maria Alice Zarur Coelho1. (1) Escola de Química, Universidade Federal do Rio de Janeiro, CT, Bloco E, Sala 103, Rio de Janeiro, Brazil, (2) Ppgeq, Universidade do Estado do Rio de Janeiro, Rua Sao Francisco Xavier 524 / PHLC/ Sala 427, Rio de Janeiro, Brazil
Drilling fluid has many functions as carry stones from the hole permitting their separation at sea surface, cool and clean the bit, reduce friction between the drill pipe and wellbore, maintain the stability of the wellbore, prevent the inflow of fluids from the wellbore and form a thin, low-permeable filter cake. The use of drilling fluid reduces wellbore productivity, because it deposit as a filter cake on the wellbore wall.
Laboratory studies have demonstrated that drill-in fluid filter cake can be effectively removed through the application of a newly developed technique incorporating an enzyme-based polymer degradation system. The drill-in fluids are typically comprised of starch, the most important component of the filter-cake. Starch in water-base drilling fluids increases viscosity for friction reduction and lubrication. The amylases are highly efficient to degrade native and chemically modified starches, the α-amylases hydrolyze starch molecules to fine diverse products as dextrin, and progressively smaller polymers composed of glucose units.
Studies herein reported the characterization of four α-amylases and defined the most qualified enzyme to attempt the standards used on this system. Results achieved prove that hydrostatic pressure can been used to increase the activity and stability as well as reported for different enzymes, including thermolysin, in literature.
Laboratory studies have demonstrated that drill-in fluid filter cake can be effectively removed through the application of a newly developed technique incorporating an enzyme-based polymer degradation system. The drill-in fluids are typically comprised of starch, the most important component of the filter-cake. Starch in water-base drilling fluids increases viscosity for friction reduction and lubrication. The amylases are highly efficient to degrade native and chemically modified starches, the α-amylases hydrolyze starch molecules to fine diverse products as dextrin, and progressively smaller polymers composed of glucose units.
Studies herein reported the characterization of four α-amylases and defined the most qualified enzyme to attempt the standards used on this system. Results achieved prove that hydrostatic pressure can been used to increase the activity and stability as well as reported for different enzymes, including thermolysin, in literature.