Abstract: A self-contained, programmable temperature sensor is positioned within a suitable pressure housing affixed to a borehole tool to record and store temperature data at predetermined times during operations of the borehole tool in a borehole penetrating a subsurface formation. The depth of the temperature sensor within the borehole corresponding to each temperature reading is recorded. After the borehole tool is removed from the borehole, the temperature sensor is removed from the pressure housing and the stored temperature data is retrieved for use in producing a record of borehole temperature versus depth within the borehole at the programmed times.

Abstract: A method of improving the permeability of a hydrocarbon bearing formation such as a coal seam by electrolinking a first well and a second well which have been drilled into the formation. Both wells are completed with similar strings of casing. The portion of the casing string which passes into or through the formation is comprised of alternating sections of electrically conductive and nonconductive material. An electrode is lowered into each well into contact with one of the electrically conductive sections. Current is then flowed between the electrodes in the wells until a permeable path through the formation is established. Then one or both electrodes are moved into contact with different conductive sections within the respective wells and the procedure is repeated.