Patent ID: 7543643

Claim:
An apparatus for heating a segment of an oil or gas well bore and surrounding strata comprising: an electrical resistance heating rod; an electrical cable for carrying electrical current from an electrical current source to said electrical resistance heating rod; at least one surface electrical lead having first and second ends, said first end being connected to said electrical cable to form a first electrical junction; at least one surface connector pin having distal and medial ends, said distal end being connected to said second end of said at least one surface electrical lead to form a second electrical junction; at least one heating rod electrical lead having first and second ends, said first end of said at least one heating rod electrical lead being connected to said electrical resistance heating rod to form a third electrical junction; at least one downhole connector pin having distal and medial ends, said distal end of said at least one downhole connector pin being connected to said second end of said at least one heating rod electrical lead to form a fourth electrical junction, wherein said medial end of said at least one downhole connector pin reversibly connects with said medial end of said at least one surface connector pin to form a pin connection, such that electrical current may be carried from said electrical cable to said first electrical junction, said second electrical junction, said pin connection, said third electrical junction, said fourth electrical junction, and said electrical resistance heating rod; a protective block comprising an upper portion and a lower portion, said upper portion having embedded therein the respective portions of said at least one surface electrical lead and said at least one surface connector pin as connect one to the other, said lower portion having embedded therein the respective portions of said at least one heating rod electrical lead and said at least one downhole connector pin as connect one to the other, each of said upper and lower portions further having a distal section and a medial section, said distal sections of said upper and lower portions containing a moldable material which, when cured, is substantially impervious to pressure and chemical permeation; and a metallic encasement member encasing said protective block and sealingly connecting said upper portion to said lower portion of said protective block via a mechanical coupling that, when said mechanical coupling is coupled, forms a substantially impervious enclosure with said protective block.