Design and Field Testing of a Permanent Magnet Induction Heater Tool for Paraffin Abatement

Abstract A downhole, permanent magnet (PM), induction heater tool for paraffin abatement has been developed and field tested. The objective of the tool is to generate heat and raise the oil temperature sufficiently to prevent paraffin from forming in the well as oil is pumped to the surface. The tool is installed in the well tubing just below the location where paraffin is forming. Tool power is provided by the pump jack and the motion of a lead-screw installed in the sucker rod string. The bulk of the heat is generated inductively by a conductive cylinder rotating in a permanent magnet array and transferred to the oil as it passes through the tool. The tool provides heat at the location where it is needed rather than heating the entire wellbore without the need of electrical wires. Significant analysis and laboratory validation tests were performed on tool components prior to moving to a prototype field test. Laboratory and field experiences have been incorporated into the latest commercial design resulting in simplified installation, improved reliability, longevity and flexibility to work in a range of well operating parameters. A number of tools have been manufactured and five have been successfully installed and operated in commercial wells. Five field tests have been conducted and all tools were successfully installed with standard workover rigs. The results from operating these tools over a period of weeks to years are presented in this paper. This paper also presents an overview of the latest "Gen III" tool design and operating data from the most recent field test.