Methods of removing water-based drilling fluids and compositions

摘要

The present invention provides methods and compositions for removing a water-based drilling fluid from surfaces in a well bore and leaving the surfaces water-wet. A method of the invention basically comprises the following steps. A water-based drilling fluid removal solution comprised of water and a mixture of a sulfonated kraft lignin salt and an N-methyl-N-oleyltaurine salt dissolved therein is provided. The drilling fluid is displaced from the well bore and the well bore surfaces are contacted with the removal solution to thereby remove the drilling fluid from the surfaces and make the surfaces water-wet.