Experimental drill hole logging in potash deposits of the Carlsbad district, New Mexico

Experimental logging of holes drilled through potash deposits in the Carlsbad district, southeastern New Mexico, demonstrate the considerable utility of gamma-ray, neutron, and electrical resistivity logging in the search for and identification of mineable deposits of sylvite and langbeinite. Such deposits are strongly radioactive with both gamma-ray and neutron well logging. Their radlioactivity serves to distinguish them from claystone, sandstone, and polyhalite beds and from potash deposits containing carnallite, leonite, and kainite. These latter strata and deposits are radioactive with gamma-ray logging but yield no radiation with neutron logging. Porous beds, such as sandstone strata, and solution cavities, such as those commonly formed in potash deposits by rotary drilling of evaporites, are less resistive than other materials. Low resistivity provides a means for differentiating between potash deposits and polyhalite beds on electrical resistivity logs of holes drilled with fresh-water and salt-base muds.