NOVELTY - Well bore casings are formed and repaired by coupling an end (14) of a first tubular member (10) to an end of a tubular sleeve (16), an end (26) of a second tubular member (28) to another end of the tubular sleeve, and ends of the first and second tubular members; and expanding and plastically deforming the first and second tubular members.    USE - For forming and repairing well bore casings to facilitate oil and gas exploration.    ADVANTAGE - The method is reliable and produces satisfactory results. It avoids damage of the threaded connections during the radial expansion process. The threaded connections between adjacent tubular members are sufficiently coupled to permit the transmission of energy through the tubular members from the surface to a downhole location.    DETAILED DESCRIPTION - INDEPENDENT CLAIMS are also included for:    (a) casing strings comprising a tubular sleeve, and tubular members;    (b) a method of extracting geothermal energy from a subterranean source of geothermal energy, comprising drilling a borehole that traverses the subterranean source of geothermal energy, positioning a first casing string within the borehole, expanding and plastically deforming the first casing string within the borehole, positioning a second casing string within the borehole, overlapping a portion of the second casing string with a portion of the first casing string, expanding and deforming a second casing string, and extracting geothermal energy from the subterranean source using the casing strings; and    (c) an apparatus for extracting geothermal energy from a subterranean source of geothermal energy, comprising a borehole and casing strings.    DESCRIPTION OF DRAWING(S) - The figures show fragmentary cross-sectional views of a first tubular member having an internally threaded connection at an end portion, placement of a tubular sleeve onto the end portion of the first tubular member, coupling of an externally threaded connection at an end portion of a second tubular member, radial expansion and plastic deformation of a first tubular member portion, and continued radial expansion and plastic deformation of the threaded connection between the tubular members and the tubular sleeve.    First tubular member (10)    First tubular member end (14)    Tubular sleeve (16)    Second tubular member end (26)    Second tubular member (28)