The steel drill string attached to a drilling bit during typical rotary
drilling operations used to drill oil and gas wells is used for a second
purpose as the casing that is cemented in place during typical oil and
gas well completions. Methods of operation are described that provide for
the efficient installation of a cemented steel cased well wherein the
drill string and the drill bit are cemented into place during one single
drilling pass down into the earth. A stabilizer is attached to the drill
string that is used to centralize the drill string in the well during
cementing operations. A one-way cement valve is installed near the drill
bit of the drill string that allows the cement to set up efficiently
under ambient hydrostatic conditions while the drill string and drill bit
are cemented into place during one single drilling pass into the earth.