providing a pipe seal assembly that includes a sleeve with a leading receptacle and a trailing receptacle that are joined together at an internal annular flange;

pushing the pipe seal assembly in a boring direction onto a leading casing pipe section that accommodates a leading auger flight, such that an end of the leading casing pipe section inserts into the leading receptacle and confronts the internal annular flange; and

pushing a trailing casing pipe section that accommodates a trailing auger flight in the boring direction, such that an end of the trailing casing pipe section inserts into the trailing receptacle and confronts the internal annular flange;

wherein the leading casing pipe section and the trailing casing pipe section abut against opposite sides of the internal annular flange;

providing a leading sealing ring in the leading receptacle;

compressing the leading sealing ring between the leading receptacle and the leading casing pipe section;

providing a trailing sealing ring in the trailing receptacle;

compressing the trailing sealing ring between the trailing receptacle and the trailing casing pipe section; and

wherein the internal annular flange is interposed between and abuts against the leading sealing ring and the trailing sealing ring.