Engineered Internal Downhole Coating Solutions for Corrosion & Deposition Control in Downhole Production Tubulars

Abstract

Abstract During the last decade, DuPont™ has been developing an engineered fluoropolymer based internal downhole coating system, for downhole production tubes. This development work came as a response to critical needs expressed by major oil and gas producers in Europe, the Middle East and Northern / Latin America, in order to have a polymeric based coating solution that could be applied internally in downhole production tubes for the purpose of: Offering an enhanced corrosion resistance in HP/HT (8000 psi / 350 Deg F) sour and sweet corrosive environments Reducing substantially difficult type of organic and inorganic depositions, such as asphaletene, paraffin and BaSO4 scale. The ultimate objective of this exercise is to offer the oil and gas industry a reliable and sustainable static solution that would not require costly intervention for wells clean-up and maintenance and also to reduce the number of workovers required on oil and gas well producers, which would ensure lower production cost. In order to develop such a new polymeric solution, a new approach versus the resin matrix design had to be used. The new coating system has an effective combination of a very low finished surface energy coupled with an improved pressure / temperature design envelope. Given the inherent design envelope limitations of current coating systems used by the oil and gas industry, fluoropolymers were selected in order to develop such a new internal downhole coating system. The high thermal stability and high flexibility of fluoropolymer-based materials provide a significant advantage in terms of mechanical properties retention in high pressure and high temperature environments, which is a must for an effective internal corrosion control. On the other hand, it has the lowest sticking tendency versus difficult type of organic and inorganic depositions, such as asphaltene and BaSO4, which provides an opportunity for a new cost effective approach in terms of maintaining oil and gas producing wells prone to such problems.