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. Methods of operation are described
wherein at least one geophysical parameter is measured with a geophysical parameter
sensing member located within the drill string. 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.