(under subclass 65) Processes comprising the step of treating a subsurface earth formation during drilling (1) to prevent the loss of drilling fluid into such formation or (2) to prevent the earth formation of the bore wall from collapsing into the earth bore.
SEE OR SEARCH THIS CLASS, SUBCLASS:
64, for processes including a chemical reaction with the formation or a drilling fluid constituent during drilling.
SEE OR SEARCH CLASS
166, Wells,
285+, and the search there noted for processes of cementing, plugging or consolidating a subsurface earth formation while drilling is interrupted.
