Patent · US Expired

Temperature limited heaters with thermally conductive fluid used to heat subsurface formations

US7383877B2 · kind B2 · utility

140Cited by
749References
30Claims
0Family size

Assignee

Inventors

Key dates

Filing dateApr 22, 2005
Grant dateJun 10, 2008
Priority date
Expiry dateDec 10, 2025

Classification

  • Technology area (CPC H)Electricity
  • CPC primaryH05B3/141
  • WIPO fieldCivil engineering
  • WIPO sectorOther fields

Abstract

Certain embodiments provide a system including a heater. The heater includes one or more electrical conductors. The heater is configured to generate a heat output during application of electrical current to the heater. The heater includes a ferromagnetic material. A conduit at least partially surrounds the heater. A fluid is located in a space between the heater and the conduit. The fluid has a higher thermal conductivity than air at standard temperature and pressure (STP) (0° C. and 101.325 kPa). The system is configured to provide (a) a first heat output below a selected temperature when time-varying electrical current is applied to the heater, and (b) a second heat output near or above the selected temperature when time-varying electrical current is applied to the heater.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.