a method and apparatus for conducting earth borehole operations include a reel of continuous coiled casing , and an injector for moving the coiled casing . the bottomhole assembly including at least a motor and a bit is connected to the free end of the coiled casing , and injected into the earth while circulating fluid through the coiled casing to form a drilled earth borehole having a borehole wall . the coiled casing drill string may be retrieved from the borehole , the bottomhole assembly removed , and the coiled casing again injected into the borehole , then suspended from a wellhead assembly . after severing the coiled casing , a bonding agent such as a cementitious material may be injected into the suspended coiled casing and into the annulus between the coiled casing and the borehole .