发明名称 |
Temperature limited heaters with relatively constant current |
摘要 |
Certain embodiments provide a system configured to heat a subsurface formation. The system includes an electrical power supply. A heater section includes one or more electrical conductors electrically coupled to the electrical power supply. At least one of the electrical conductors includes ferromagnetic material. The heater section provides a first heat output when time-varying electrical current is applied to the heater section below a selected temperature, and a second heat output approximately at and above the selected temperature during use. The second heat output is reduced compared to the first heat output. The system is configured to allow heat to transfer from the heater section to a part of the formation. The electrical power supply is configured to provide a relatively constant amount of time-varying electrical current that remains within about 15% of a selected constant current value when a load of the electrical conductors changes.
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申请公布号 |
US7481274(B2) |
申请公布日期 |
2009.01.27 |
申请号 |
US20050112878 |
申请日期 |
2005.04.22 |
申请人 |
SHELL OIL COMPANY |
发明人 |
VINEGAR HAROLD J.;SANDBERG CHESTER LEDLIE;HARRIS CHRISTOPHER KELVIN |
分类号 |
E21B36/04;E21B29/00;E21B43/00;E21B43/12;E21B43/24;E21B43/30;E21B43/38;H05B3/10;H05B3/14;H05B6/10 |
主分类号 |
E21B36/04 |
代理机构 |
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代理人 |
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主权项 |
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地址 |
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